A quick-drying water-based coating system

Abstract

The invention discloses a quick-drying water-based coating system, comprising at least one first coating layer and at least one second coating layer, characterized in that the first coating layer is formed by a first coating composition, and the second coating layer is formed by a second coating composition; wherein the first coating composition comprises: a cross-linkable component (A) and an amine curing agent; the second coating composition comprises: a cross-linkable component (B) and a polyisocyanate curing agent; the cross-linkable component (A) comprises: a water-based epoxy resin dispersion, and the epoxy value of the water-based epoxy resin dispersion is The cross-linkable component (B) comprises an aqueous hydroxylated acrylic resin dispersion having a hydroxyl value of 100 to 140 mgKOH / g, a pH value of 6.5 to 7.5, a solid acid value of 18 to 25 mgKOH / g, a number average molecular weight of 5000 to 10000, and a particle size of 100 to 180 nm.

Description

Technical Field

[0001] The present invention relates to the field of coatings, and more specifically to a quick-drying waterborne epoxy coating and waterborne polyurethane coating system and a preparation method thereof. Background Art

[0002] In recent years, in order to accelerate the optimization of the coatings industry and the pace of environmental protection, the Chinese government has advocated that coatings suppliers transform and upgrade coatings products and maintain sustainable development. At the same time, the state also provides policy guidance for coatings production and consumption companies. According to national regulations, consumption tax is levied on coatings manufacturers whose volatile organic compound (VOC) content under construction is higher than 420g / L (inclusive), and VOC emission tax is levied on coatings users, which has accelerated the control of VOC pollution sources by enterprises and the development and application of environmentally friendly coatings. Driven by national environmental protection policies, the application of coatings in steel structures, commercial vehicles, construction machinery, rail transit, wood products and other fields is changing and developing from oil-based to water-based applications.

[0003] Two-component epoxy coatings are usually formed by chemical crosslinking of epoxy and amine into a three-dimensional network structure. The epoxy-amine crosslinking structure contains soft ether bonds and rigid phenyl groups, which give the paint film excellent toughness. The epoxy group and the amine group can form a strong interaction with the metal surface. This structural feature gives epoxy coatings excellent adhesion and anti-corrosion properties on metal surfaces, and also outstanding performance in chemical resistance, oil resistance, and especially alkali resistance. Two-component polyurethane coatings are usually formed by crosslinking structures of hydroxy acrylic acid and isocyanate curing agent. The strong polar urethane groups on the polyurethane molecular chain give it high cohesive energy, and the molecular chains form hard segment microphases in the form of hydrogen bonds. At the same time, the weakly polar flexible segments in the polyurethane molecular chain are easy to aggregate to form soft phases. This unique "hard-soft" microphase structure of polyurethane makes its coating have good adhesion, appearance, chemical resistance, hardness, and excellent wear resistance and weather resistance.

[0004] At present, epoxy coating and polyurethane coating systems have good anti-corrosion, weather resistance, appearance, chemical resistance and other characteristics, and can be used in steel structures, commercial vehicles, construction machinery, rail transit and other fields. Traditional solvent-based epoxy coatings and polyurethane coatings emit a large amount of VOCs into the air during the manufacturing, construction, drying, curing and film-forming processes, causing serious pollution and threats to the human ecological environment. Therefore, water-based epoxy and water-based polyurethane coatings are becoming more and more popular. With the promotion of environmental protection policies and the improvement of environmental awareness among coating consumers, water-based epoxy and water-based polyurethane coating systems will be widely promoted and applied in construction machinery, rail transit and subways. Compared with oil-based systems, water-based systems have slow drying speeds in construction applications. When polyurethane coatings are matched with epoxy coating systems, epoxy coatings need to be baked, resulting in high energy consumption, slow production rhythm, and high-thickness polyurethane coatings are prone to bubble bursting. These problems have largely limited the promotion and use of water-based epoxy and water-based polyurethane coating systems.

[0005] In view of this, it is necessary to provide a quick-drying water-based epoxy coating and water-based polyurethane coating system and a preparation method thereof. In this coating system, the epoxy coating dries quickly, and the polyurethane coating can be sprayed without baking, thereby reducing the energy consumption of water-based paint and improving production efficiency. The polyurethane coating has a good bubble film thickness and meets normal industrial production requirements. At the same time, the epoxy coating combined with the polyurethane coating has good corrosion resistance, chemical resistance, water resistance, and weather resistance, and can be used in industrial protection fields such as steel structures, commercial vehicles, and construction machinery. Summary of the invention

[0006] The purpose of the present invention is to provide a quick-drying coating system, including a water-based epoxy coating and a water-based polyurethane coating, so as to solve the problems of slow drying speed of water-based paint in construction application, high energy consumption and low production efficiency caused by baking of the epoxy coating when the polyurethane and epoxy coatings are matched, and easy bubble bursting of the high-thickness polyurethane coating.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A quick-drying coating system, comprising at least one first coating layer and at least one second coating layer; the first coating layer is formed by a first coating composition, and the second coating layer is formed by a second coating composition; wherein the first coating composition comprises: a crosslinkable component (A) and an amine curing agent; and the second coating composition comprises: a crosslinkable component (B) and a polyisocyanate curing agent;

[0009] The crosslinkable component (A) comprises: an aqueous epoxy resin dispersion, wherein the epoxy value of the aqueous epoxy resin dispersion is 450-550 mol / 100 g, the pH value is 7.5-8.5, the solid content is 50-55%, and the particle size is 0.8-1.0 μm; and

[0010] The crosslinkable component (B) includes: an aqueous hydroxy acrylic resin dispersion, wherein the aqueous hydroxy acrylic resin dispersion has a hydroxyl value of 100 to 140 mgKOH / g, a pH value of 6.5 to 7.5, a solid acid value of 18 to 25 mgKOH / g, a number average molecular weight of 5000 to 10000, and a particle size of 100 to 180 nm.

[0011] In some embodiments, the mass ratio of the crosslinkable component (A) to the amine curing agent is 100:(10-20).

[0012] In some embodiments, the ratio of the active hydrogen equivalent weight (AHEW) in the amine curing agent to the epoxy equivalent weight (EEW) in the crosslinkable component (A) is (0.8-1):1.

[0013] In some embodiments, the aqueous epoxy resin dispersion is obtained by copolymerizing a solid epoxy resin with a polyether to obtain a polymer with uniform molecular weight distribution and segments with hydrophilic groups, and then further emulsifying to obtain an aqueous epoxy emulsion with a core-shell structure.

[0014] In some embodiments, the water-based epoxy resin dispersion is selected from one or a mixture of the water-based epoxy emulsion XS0402 of Honghui New Materials Technology Co., Ltd., the water-based epoxy emulsion model PZ3961-1 of Huntsman Chemical Co., Ltd., and the water-based epoxy emulsion model EP387W of Allnex Resins (China) Co., Ltd.

[0015] In some embodiments, the amine curing agent is a 40-60 wt % water-based epoxy amine curing agent.

[0016] In some embodiments, the waterborne epoxy curing agent is an aqueous solution of a modified alicyclic polyamine adduct.

[0017] In some embodiments, the water-based epoxy amine curing agent is selected from one or a mixture of XS0608C of Honghui New Materials Technology Co., Ltd., Aradur 38-1 of Huntsman Co., Ltd., and BECKOPOXTM EH613w / 80WA of Allnex Resins (China) Co., Ltd.

[0018] In the present application, the waterborne epoxy amine curing agent is a high-viscosity polymer. When used alone in a waterborne epoxy coating composition (i.e., the first coating composition), the miscibility between the crosslinkable component (A) and the curing agent is poor, thereby affecting the crosslinking density. Therefore, in the present application, the mixing compatibility problem between the crosslinkable component (A) and the waterborne epoxy amine curing agent is effectively solved by using a pure water dilution method, so that the obtained waterborne epoxy coating composition (i.e., the first coating composition) has good construction applicability and can form a three-dimensional polymer material coating when dried at room temperature.

[0019] In some embodiments, the ratio of the NCO groups of the polyisocyanate curing agent to the OH groups of the crosslinkable component (B) is (1-1.5):1.

[0020] In some embodiments, the aqueous hydroxy acrylic resin dispersion includes aqueous hydroxy acrylic resin A, which is obtained by free radical copolymerization of acrylate monomers and vinyl monomers to obtain a polymer with uniform molecular weight distribution and chain segments with active groups that can participate in curing and cross-linking, and further emulsified to obtain aqueous hydroxy acrylic resin A with a core-shell structure.

[0021] In some embodiments, the water-based hydroxyl acrylic resin A is selected from the water-based hydroxyl acrylic resin of Covestro Polymer (China) Co., Ltd. with the model number Bayhydrol A 2601, the water-based hydroxyl acrylic resin of Covestro Polymer (China) Co., Ltd. with the model number Bayhydrol A 145, the water-based hydroxyl acrylic resin of Covestro Polymer (China) Co., Ltd. with the model number Bayhydrol A 2542, the water-based hydroxyl acrylic resin of Allnex Resins (China) Co., Ltd. with the model number A mixture of one or more of the water-based hydroxy acrylic resin of 6511 and the water-based hydroxy acrylic resin of Antkote2035 produced by Yantai Wanhua.

[0022] In some embodiments, the aqueous hydroxyl acrylic resin dispersion further comprises an aqueous hydroxyl acrylic resin B, wherein the aqueous hydroxyl acrylic resin B is selected from the aqueous hydroxyl acrylic resin of model Bayhydrol A 2601 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxyl acrylic resin of model Bayhydrol A 145 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxyl acrylic resin of model Bayhydrol A 2542 of Covestro Polymers (China) Co., Ltd., ... One or a mixture of the water-based hydroxy acrylic resin of 6511 and the water-based hydroxy acrylic resin of Antkote 2035 produced by Yantai Wanhua.

[0023] In some embodiments, the mass ratio of the aqueous hydroxylated acrylic resin A to the aqueous hydroxylated acrylic resin B is (2-5):1.

[0024] In some embodiments, the crosslinkable component (A) further comprises an anti-rust pigment, and the anti-rust pigment is selected from at least one of a composite hybrid phosphate anti-rust pigment and a composite molybdate anti-rust pigment.

[0025] In some embodiments, the crosslinkable component (A) further comprises a co-solvent, and the co-solvent is selected from at least one or more mixtures of propylene glycol methyl ether, propylene glycol phenyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

[0026] In some embodiments, the crosslinkable component (B) further comprises a film-forming solvent, and the film-forming solvent is selected from at least one or more mixtures of ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

[0027] In some embodiments, at least one of the crosslinkable component (A) or the crosslinkable component (B) further comprises a filler, and the filler is selected from at least one of talc powder, feldspar powder, barite powder, precipitated barium sulfate, and mica powder.

[0028] In some embodiments, at least one of the crosslinkable component (A) or the crosslinkable component (B) further comprises a pigment, and the pigment is selected from at least one of titanium white, carbon black, and an organic pigment.

[0029] In some embodiments, at least one of the crosslinkable component (A) or the crosslinkable component (B) further comprises an auxiliary agent, wherein the auxiliary agent is selected from at least one of a dispersant, a defoamer, a substrate wetting agent, and a rheological additive.

[0030] In some embodiments, the crosslinkable component (B) further comprises a functional auxiliary agent, which is at least one of an ultraviolet light absorber and a hindered amine light stabilizer.

[0031] In some preferred embodiments, the present application provides a fast-drying coating system, comprising at least one first coating layer and at least one second coating layer; the first coating layer is formed by a first coating composition, and the second coating layer is formed by a second coating composition; wherein,

[0032] The first coating composition comprises: a cross-linkable component (A) and an amine curing agent;

[0033] The crosslinkable component (A) comprises the following components in parts by weight (based on 100 parts by weight of the total crosslinkable component (A):

[0034]

[0035] The amine curing agent comprises the following components in parts by weight (based on 100 parts by total weight of the amine curing agent):

[0036] 40-60 parts of water-based epoxy amine curing agent;

[0037] 45-60 parts of deionized water;

[0038] A water-based epoxy resin dispersion, wherein the epoxy value of the water-based epoxy resin dispersion is 450-550 mol / 100 g, the pH value is 7.5-8.5, the solid content is 50-55%, and the particle size is 0.8-1.0 μm; and

[0039] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:(10-20);

[0040] The second coating composition comprises: a crosslinkable component (B) and a polyisocyanate curing agent;

[0041] The crosslinkable component (B) comprises the following components in parts by weight (based on 100 parts by weight of the total crosslinkable component (B):

[0042]

[0043] The aqueous hydroxy acrylic resin dispersion has a hydroxyl value of 100 to 140 mgKOH / g, a pH value of 6.5 to 7.5, a solid acid value of 18 to 25 mgKOH / g, a number average molecular weight of 5000 to 10000, and a particle size of 100 to 180 nm; and

[0044] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:(15-30).

[0045] In some embodiments, based on 100 parts by weight of the total crosslinkable component (A), the auxiliary agent included in the crosslinkable component (A) includes the following components in parts by weight:

[0046]

[0047] In some embodiments, based on 100 parts by weight of the total crosslinkable component (B), the auxiliary agent included in the crosslinkable component (B) includes the following components in parts by weight:

[0048]

[0049] The beneficial effects of the present invention are as follows:

[0050] The quick-drying waterborne epoxy coating and waterborne polyurethane coating system provided by the present invention has good construction operability and final coating performance. The waterborne epoxy coating has a fast drying speed, and the polyurethane coating can be sprayed without baking, which reduces baking energy consumption and improves production efficiency. The polyurethane coating has a good bubble burst film thickness and is suitable for industrial production. At the same time, the epoxy coating combined with the polyurethane coating has good corrosion resistance, chemical resistance, water resistance, and weather resistance, and can be applied to industrial protection fields such as steel structures, commercial vehicles, and engineering machinery. DETAILED DESCRIPTION

[0051] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0052] According to a specific embodiment of the present invention, a quick-drying coating system is provided, comprising at least one layer of water-based epoxy coating (first coating) and at least one layer of water-based polyurethane coating (second coating).

[0053] In this embodiment, the first coating, i.e., the waterborne epoxy coating, is formed by a first coating composition, which comprises: a crosslinkable component (A) and an amine curing agent, wherein:

[0054] The crosslinkable component (A) comprises:

[0055] Based on 100 parts by weight of the total crosslinkable component (A), the following components are included:

[0056]

[0057] Component B, including:

[0058] The total weight of the amine curing agent is 100 parts, including the following components in parts by weight:

[0059] 40-60 parts of water-based epoxy amine curing agent

[0060] 40-60 parts of deionized water

[0061] Wherein, the mass ratio of the cross-linkable component (A) to the amine curing agent is 100:10-20.

[0062] In the first coating composition formed by the cross-linkable component (A) and the amine curing agent, by adjusting the ratio of the water-based epoxy resin dispersion and the amine curing agent in the formula, the chemical reaction rate and cross-linking density of the water-based epoxy coating can be effectively adjusted, and the epoxy coating can be adjusted to a high quick-drying film thickness.

[0063] At the same time, the selection of waterborne epoxy resin dispersion in the formula and the use of amine curing agent in a preferred ratio can effectively remove bubbles during production and construction, avoiding shrinkage holes in the epoxy coating during construction. The polymer cross-linked coating formed by this epoxy coating has high adhesion, stable structure, excellent appearance, no defects, good salt spray resistance, water resistance, chemical resistance and other properties, which can match the waterborne polyurethane coating well.

[0064] It can be understood that in this embodiment, the water-based epoxy resin dispersion is formed by dispersing the water-based epoxy resin in water.

[0065] In a preferred example, in the amine curing agent, the amine curing agent is a water-based epoxy amine curing agent. The water-based epoxy amine curing agent is a high-viscosity polymer, which is used alone in a water-based epoxy coating composition to cause poor miscibility between epoxy resin and curing agent, thereby affecting the crosslinking density. In this example, the use of pure water dilution effectively solves the problem of mixed compatibility between the crosslinkable component (A) and the water-based epoxy amine curing agent, so that the obtained composition has good construction applicability and can form a three-dimensional polymer material coating under room temperature drying.

[0066] Furthermore, the water-based epoxy amine curing agent is an aqueous solution of a modified alicyclic polyamine adduct.

[0067] In a preferred example, the waterborne epoxy resin dispersion has an epoxy value of 450-550 mol / 100 g, a pH value of 7.5-8.5, a solid content of 53±2%, and a particle size of 0.8-1.0 μm based on solid resin.

[0068] In a preferred example, the anti-rust pigment is selected from at least one of complex hybrid phosphates and complex molybdates.

[0069] In a preferred example, the pigment is selected from at least one of titanium white, carbon black, and organic pigments.

[0070] In a preferred example, the filler is selected from at least one of talc powder, feldspar powder, barite powder, precipitated barium sulfate, and mica powder.

[0071] In a preferred example, the co-solvent is an alcohol ether solvent. Exemplary film-forming solvents include, but are not limited to, at least one or more selected from propylene glycol methyl ether, propylene glycol phenyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

[0072] In a preferred example, based on 100 parts by weight of the total crosslinkable component (A), the auxiliary agent includes the following components in parts by weight:

[0073]

[0074] In the present application, by using the above-mentioned specific proportions of the auxiliary agent components in combination, the bubbles generated during the production and construction process can be further effectively removed, while the drying property of the epoxy paint film can be improved during the construction process.

[0075] In a preferred example, the above dispersant is Additol VXW 6208, a product of Allnex. VXW 6374 or at least one of DIS-2012 and DIS-2055 produced by Peak.

[0076] In a preferred example, the defoamer comprises a polydimethylsiloxane defoamer and an acetylene glycol defoamer. The polydimethylsiloxane defoamer is preferably a mixture of at least one or more of Evonik's TEGO Foamex 825 and TEGO Airex 901W, BYK024, and BYK 028; the acetylene glycol defoamer is preferably a mixture of at least one or more of Evonik's series products SURFYNOL104BC, SURFYNOL 107L, and SURFYNOL 440.

[0077] In a preferred example, the substrate wetting agent is an organic modified siloxane, which can effectively reduce surface tension. Exemplary substrate wetting agents include, but are not limited to, BYK 345, BYK 346, BYK349, BYK 346 ...

[0078] In a preferred example, the rheological additive is a nonionic polyurethane associative thickener, which can effectively adjust the viscosity of low shear and high shear, and the thickener is obtained by nonionic hydrophobic modification. Preferably, it is a mixture of at least one or more of the series products WT-202 and WT-102 of Deqian Chemical (China) Co., Ltd., or SN-THICKER 660T and SN-THICKER 640T of Sannokop Co., Ltd. The rheological additive in the formula can effectively adjust the low shear viscosity and high shear viscosity during the construction process, and can improve the rheological behavior during the construction process.

[0079] In this embodiment, the second coating, i.e., the waterborne polyurethane coating, is formed by a second coating composition, wherein the second coating composition comprises: a crosslinkable component (B) and a polyisocyanate curing agent, wherein:

[0080] The crosslinkable component (B) comprises:

[0081] Based on 100 parts by weight of the total crosslinkable component (B), the following components are included:

[0082]

[0083] Wherein, the mass ratio of the cross-linkable component (B) to the polyisocyanate curing agent is 100:15-30.

[0084] In the present application, in the waterborne polyurethane coating formed by the crosslinkable component (B) and the polyisocyanate curing agent, the chemical reaction rate and crosslinking density of the waterborne polyurethane coating can be effectively adjusted by adjusting the ratio of the waterborne hydroxy acrylic resin dispersion and the polyisocyanate curing agent in the formula, so as to adjust the waterborne polyurethane coating to the highest bubble-bursting film thickness. At the same time, in the above-mentioned formula, by selecting the waterborne hydroxy acrylic resin dispersion and using the polyisocyanate curing agent in a preferred ratio range, the bubbles in the production and construction process can be effectively removed, and the bubble-bursting problem of the waterborne polyurethane coating during the construction process is avoided. And the polymer cross-linked coating formed by this waterborne polyurethane coating has high gloss, stable structure, excellent appearance, no defects, good salt spray resistance, water resistance, chemical resistance and other properties, and can be well matched with the two-component epoxy coating.

[0085] It can be understood that in this embodiment, the aqueous hydroxy acrylic resin dispersion is formed by dispersing the aqueous hydroxy acrylic resin in water.

[0086] In a preferred example, the polyisocyanate curing agent also contains an urethane grade solvent. In the present application, the polyisocyanate curing agent is a hydrophobic curing agent, which is used alone in a waterborne polyurethane coating composition and has poor dispersibility in water, which will affect the crosslinking characteristics. Therefore, in this example, the solvent dilution method can effectively solve the problem of mixing compatibility between the crosslinkable component (B) and the polyisocyanate curing agent, so that the obtained composition has good construction applicability, can form a three-dimensional polymer material coating under room temperature drying and low temperature baking conditions, and reduce the occurrence of blistering during construction.

[0087] Furthermore, the polyisocyanate curing agent is a low-viscosity asymmetric trimer of hexamethylene diisocyanate, preferably one of Asahi Kasei's Duranate TLA100 and Duranate TUL-100, or one of Covestro (China) Co., Ltd.'s series products Desmodur N 3900 and Desmodur 3600.

[0088] Furthermore, the urethane-grade solvent is preferably DOWANOLTM MPMA, DOWANOLTM PGDA, or PROGLYDETM DMM produced by Dow Chemical (China) Co., Ltd.

[0089] In a preferred example, the aqueous hydroxylated acrylic resin dispersion has a hydroxyl value (based on solid content) of 100-140 mgKOH / g, a pH value of 6.5-7.5, a solid acid value of 18-25 mgKOH / g, a number average molecular weight of 5000-10000, and a particle size of 100-180 nm.

[0090] In yet another example, the aqueous hydroxylated acrylic resin dispersion comprises at least two aqueous hydroxylated acrylic resins.

[0091] In another example, in the aqueous hydroxyl acrylic resin dispersion, the aqueous hydroxyl acrylic resin is selected from aqueous hydroxyl acrylic resin A, and the aqueous hydroxyl acrylic resin A is selected from aqueous hydroxyl acrylic resin of model Bayhydrol A 2601 of Covestro Polymer (China) Co., Ltd., aqueous hydroxyl acrylic resin of model Bayhydrol A 145 of Covestro Polymer (China) Co., Ltd., aqueous hydroxyl acrylic resin of model Bayhydrol A 2542 of Covestro Polymer (China) Co., Ltd., ... One or a mixture of the water-based hydroxy acrylic resin of 6511 and the water-based hydroxy acrylic resin of Antkote 2035 produced by Yantai Wanhua.

[0092] The waterborne hydroxy acrylic resin A is obtained by free radical copolymerization of acrylic ester monomers and vinyl monomers to obtain a polymer with uniform molecular weight distribution and active groups in the chain segments that can participate in curing and crosslinking, and further emulsified to obtain a waterborne hydroxy acrylic resin A with a core-shell structure. Based on the solid resin, the waterborne hydroxy acrylic resin A has a hydroxyl value of 100-140 mgKOH / g, a pH value of 6.5-7.5, a solid acid value of 18-25 mgKOH / g, a number average molecular weight of 5000-10000, and a particle size of 100-180 nm.

[0093] Further, the aqueous hydroxyl acrylic resin dispersion comprises a mixture of the aqueous hydroxyl acrylic resin A and the aqueous hydroxyl acrylic resin B; wherein the aqueous hydroxyl acrylic resin B is selected from the aqueous hydroxyl acrylic resin of model Bayhydrol A 2601 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxyl acrylic resin of model Bayhydrol A 145 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxyl acrylic resin of model Bayhydrol A 2542 of Covestro Polymers (China) Co., Ltd., ... One or a mixture of the water-based hydroxy acrylic resin of 6511 and the water-based hydroxy acrylic resin of Antkote 2035 produced by Yantai Wanhua.

[0094] The mass ratio of the water-based hydroxylated acrylic resin A to the water-based hydroxylated acrylic resin B is (2-5):1.

[0095] In a preferred example, the pigment is selected from at least one of titanium white, carbon black, and organic pigments.

[0096] In a preferred example, the film-forming solvent is an alcohol ether solvent. Exemplary film-forming solvents include, but are not limited to, at least one or more mixtures selected from ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

[0097] In another preferred example, based on 100 parts by weight of the total crosslinkable component (B), the auxiliary agent includes the following components in parts by weight:

[0098]

[0099] In the present application, by using the components of the auxiliary agent in the above-mentioned specific proportion range in combination, the bubbles generated during the production and construction process can be further effectively removed, thereby avoiding the problem of bubble bursting of the polyurethane coating during the construction process.

[0100] In a preferred example, the dispersant is at least one of BASF's series products Dispex Ultra PA 4550, Dispex Ultra PX 4585, Dispex Ultra PX 4275, Dispex Ultra PX 4575 or BYK's DIS-2012, DIS-2055.

[0101] In a preferred example, the defoamer comprises a polydimethylsiloxane defoamer and an acetylene glycol defoamer. The polydimethylsiloxane defoamer is preferably a mixture of at least one or more of Evonik's TEGO Foamex 825 and TEGO Airex 901W, BYK024, and BYK 028; the acetylene glycol defoamer is preferably a mixture of at least one or more of Evonik's series products SURFYNOL104BC, SURFYNOL 107L, and SURFYNOL 440.

[0102] In a preferred example, the substrate wetting agent is an organic modified siloxane, which can effectively reduce surface tension. Exemplary substrate wetting agents include, but are not limited to, BYK 345, BYK 346, BYK349, BYK 346 ...

[0103] In a preferred example, the rheological additive is a non-ionic polyurethane associative thickener, which can effectively adjust the viscosity of low shear and high shear, and the thickener is obtained by non-ionic hydrophobic modification. Preferably, it is a composite of at least one or more of ACRTSOL RM-3030NPR and ACRYSOL RM-998, a series of products of Dow Chemical (China) Co., Ltd., or RHEOLATE 350D and RHEOLATE 299 of Hemmings New Materials Technology Co., Ltd. The rheological additive in the formula can effectively adjust the low shear viscosity and high shear viscosity during the construction process, and can improve the rheological behavior during the construction process. The reasonable combination of ultraviolet absorber and hindered amine light stabilizer will make the coating have good weather resistance.

[0104] In a preferred example, the ultraviolet light absorber is preferably at least one of TINUVIN 99DW(N), TINUVIN 123DW(N), and TINUVIN1130 produced by BASF.

[0105] In a preferred example, the hindered amine light stabilizer is preferably at least one of BASF's TINUVIN 477DW (N), TINUVIN 292, and TINUVIN 400DW (N).

[0106] The technical scheme of the present invention is described below in conjunction with some specific embodiments. If not specifically described, the various raw materials of the present invention are commercially available or prepared according to conventional methods in the art. Unless otherwise specified, all professional and scientific terms used in the present invention have the same meanings as those familiar to those skilled in the art. Any method or material similar to the described content can be applied in the method of the present invention.

[0107] Example 1

[0108] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0109] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0110] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0111]

[0112]

[0113] The amine curing agent consists of a water-based epoxy amine curing agent and a solvent, and the solvent is pure water.

[0114] The waterborne epoxy resin dispersion is a waterborne epoxy emulsion XS0402 produced by Honghui New Materials Technology Co., Ltd. The emulsion has a solid content of 53%, a solid EEW of 480g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm;

[0115] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0116] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0117] The dispersant is Additol VXW 6208;

[0118] The fillers include: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, and mica powder GA-1.

[0119] The cosolvents are propylene glycol methyl ether and ethylene glycol butyl ether.

[0120] The defoamer is TEGO Airex 901W;

[0121] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0122] The content of the water-based epoxy amine curing agent is 43wt%, XS0608C from Honghui New Materials Technology Co., Ltd.

[0123] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:11, and the ratio of AHEW to EEW is 0.9.

[0124] Furthermore, the waterborne epoxy dispersion, pigment, filler, dispersant, cosolvent and defoamer are ground to a fineness of less than 30 μm by a sand mill, and then a substrate wetting agent and a rheological additive are added in sequence under high-speed stirring conditions to obtain a uniformly mixed crosslinkable component (A).

[0125] During construction, the crosslinkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0126] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0127] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0128]

[0129] The solvent of the polyisocyanate curing agent is dipropylene glycol dimethyl ether (DMM); wherein:

[0130] The aqueous hydroxy acrylic resin dispersion is a resin obtained by free radical copolymerization of acrylic ester monomers and vinyl monomers to obtain a polymer with uniform molecular weight distribution and active groups that can participate in curing and crosslinking. The polymer is further neutralized and emulsified to obtain a hydroxy acrylic resin dispersion with a core-shell structure and low solvent content and high solid content. The dispersion has a hydroxyl value of 100-140 mgKOH / g, a pH value of 6.5-7.5, a particle size of 100-180 nm, a solid acid value of 18-25 mgKOH / g, and a number average molecular weight of about 5000-10000.

[0131] The pigment is TI-PURE R-960 titanium dioxide;

[0132] The dispersant is Dispex Ultra PX 4575;

[0133] The film-forming solvent is 2.0 parts of ethylene glycol butyl ether and 3.0 parts of diethylene glycol butyl ether;

[0134] The defoamer is 0.5 parts of TEGO Foamex 825 defoamer and 0.5 parts of SURFYNOL 107L defoamer;

[0135] The substrate wetting agent is BYK 345 from BYK;

[0136] The rheological additives are 0.5 parts of ACRTSOL RM-998 and 0.5 parts of ACRTSOL RM-3030NPR;

[0137] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN1130 and TINUVIN292 respectively.

[0138] The content of the polyisocyanate curing agent is 65wt%, and the polyisocyanate curing agent is Asahi Kasei Duranate TUL-100.

[0139] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:15, and the ratio of the NCO group (isocyanate group) of the polyisocyanate curing agent to the OH group (hydroxyl group) of the crosslinkable component (B) is 1.1:1.

[0140] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0141] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0142] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0143] Example 2

[0144] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0145] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0146] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0147]

[0148] The amine curing agent is a water-based epoxy curing agent, and the solvent is pure water.

[0149] The waterborne epoxy resin dispersion is waterborne epoxy emulsion XS0402 produced by Honghui New Materials Technology Co., Ltd. The emulsion has a solid content of 53%, a solid EEW of 480g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm.

[0150] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0151] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0152] The dispersant is Additol VXW 6208;

[0153] The filler: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, mica powder GA-1;

[0154] The cosolvent is propylene glycol methyl ether and ethylene glycol butyl ether;

[0155] The defoamer is TEGO Airex 901W;

[0156] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0157] In the amine curing agent, the content of the water-based epoxy curing agent is 43wt%, XS0608C from Honghui New Materials Technology Co., Ltd.

[0158] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:16, and the ratio of AHEW to EEW is 0.9.

[0159] Furthermore, the waterborne epoxy dispersion, pigment, filler, dispersant, cosolvent and defoamer are ground to a fineness of less than 30 μm by a sand mill, and then a substrate wetting agent and a rheological additive are added in sequence under high-speed stirring conditions to obtain a uniformly mixed crosslinkable component (A).

[0160] During construction, the crosslinkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0161] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0162] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0163]

[0164]

[0165] The solvent of the polyisocyanate curing agent is propylene glycol methyl ether acetate (PMA); wherein:

[0166] The aqueous hydroxylated acrylic resin dispersion is a mixture of the aqueous hydroxylated acrylic resin dispersion described in Example 1 and Bayhydrol A 145 of Covestro Polymers (China) Co., Ltd., with the mass ratio of the two being 2 / 1.

[0167] The pigment is BASF Heliogen Blue L6930;

[0168] The dispersant is Dispex Ultra PX 4585;

[0169] The film-forming solvent is 4.0 parts of dipropylene glycol monobutyl ether, 2.0 parts of diethylene glycol butyl ether, and 2.0 parts of ethylene glycol butyl ether;

[0170] The defoamer is 1.5 parts of SURFYNOL DF-110D defoamer and 0.5 parts of BYK 028;

[0171] The substrate wetting agent is TEGO Twin 4100 from BYK;

[0172] The rheological additives are 0.5 parts of RHEOLATE 350D and 0.5 parts of RHEOLATE 299;

[0173] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN 99DW(N) and TINUVIN400DW(N) respectively.

[0174] The content of the polyisocyanate curing agent is 60wt%, and the polyisocyanate curing agent is Desmodur N 3900.

[0175] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:30, and the ratio of NCO (isocyanate group) to OH (hydroxyl group) is 1.5.

[0176] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0177] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, which is a coating-4 cup viscosity.

[0178] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0179] Example 3

[0180] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0181] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0182] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0183]

[0184] The amine curing agent is a water-based epoxy curing agent, and the solvent is pure water.

[0185] The waterborne epoxy resin dispersion is a waterborne epoxy emulsion XS0402 produced by Honghui New Materials Technology Co., Ltd. The emulsion has a solid content of 53%, a solid EEW of 480g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm;

[0186] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0187] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0188] The dispersant is Additol VXW 6208;

[0189] The filler: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, mica powder GA-1;

[0190] The cosolvent is propylene glycol methyl ether and ethylene glycol butyl ether;

[0191] The defoamer is TEGO Airex 901W;

[0192] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0193] The content of the waterborne epoxy curing agent in the amine curing agent is 43wt%, XS0608C from Honghui New Materials Technology Co., Ltd.

[0194] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:14, and the ratio of AHEW to EEW is 0.9.

[0195] Furthermore, the waterborne epoxy dispersion, pigments, fillers, dispersants, cosolvents and defoamers are ground to a fineness of less than 30 μm using a sand mill, and then substrate wetting agents and rheological additives are added in sequence under high-speed stirring conditions to obtain a uniformly mixed component A.

[0196] During construction, the cross-linkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0197] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0198] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0199]

[0200] The solvent of the polyisocyanate curing agent is propylene glycol diacetate (PGDA).

[0201] The aqueous hydroxylated acrylic resin dispersion is a product of Allnex Resins (China) Co., Ltd. A mixture of 6511, Antkote 2035 from Yantai Wanhua Chemical Group Co., Ltd. and Bayhydrol A 2542 from Covestro Polymers (China) Co., Ltd., with the mass ratio of the three being 2 / 1 / 1;

[0202] The film-forming solvent is 4.0 parts of diethylene glycol butyl ether, 1.0 parts of dipropylene glycol monobutyl ether, and 2.0 parts of ethylene glycol butyl ether;

[0203] The defoamer is 0.5 parts BYK 024 and 1.5 parts SURFYNOL 104BC defoamer;

[0204] The substrate wetting agent is TEGO Twin 4100 from BYK;

[0205] The rheological additives are 0.5 parts of ACRTSOL RM-998W and 0.5 parts of ACRTSOL RM-3030NPR;

[0206] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN 99DW(N) and TINUVIN400DW(N) respectively.

[0207] The content of the polyisocyanate curing agent is 70wt%, and the polyisocyanate curing agent is Asahi Kasei Duranate TLA100.

[0208] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:25, and the ratio of NCO (isocyanate group) to OH (hydroxyl group) is 1.3.

[0209] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0210] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, which is a coating-4 cup viscosity.

[0211] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0212] Example 4

[0213] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0214] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0215] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0216]

[0217]

[0218] The amine curing agent is a water-based epoxy curing agent, and the solvent is pure water.

[0219] The waterborne epoxy resin dispersion is a waterborne epoxy emulsion XS0402 produced by Honghui New Materials Technology Co., Ltd. The emulsion has a solid content of 53%, a solid EEW of 480g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm.

[0220] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0221] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0222] The dispersant is Additol VXW 6208;

[0223] The filler: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, mica powder GA-1;

[0224] The cosolvent is propylene glycol methyl ether and ethylene glycol butyl ether;

[0225] The defoamer is TEGO Airex 901W;

[0226] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0227] The content of the waterborne epoxy curing agent in the amine curing agent is 32wt%, and the waterborne epoxy curing agent is XS0608C from Honghui New Materials Technology Co., Ltd. and BECKOPOX from Allnex Resins (China) Co., Ltd. TM EH613w / 80WA mixed, mass ratio is 1:1.

[0228] The mass ratio of the cross-linkable component (A) to the amine curing agent is 100:15, and the ratio of AHEW to EEW is 0.9.

[0229] Furthermore, the waterborne epoxy dispersion, pigment, filler, dispersant, cosolvent and defoamer are ground to a fineness of less than 30 μm by a sand mill, and then a substrate wetting agent and a rheological additive are added in sequence under high-speed stirring conditions to obtain a uniformly mixed crosslinkable component (A).

[0230] During construction, the crosslinkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0231] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0232] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0233]

[0234]

[0235] The solvent of the polyisocyanate curing agent is propylene glycol diacetate (PGDA).

[0236] The aqueous hydroxylated acrylic resin dispersion is a product of Allnex Resins (China) Co., Ltd. A mixture of 6511, Antkote 2035 from Yantai Wanhua Chemical Group Co., Ltd. and Bayhydrol A 2542 from Covestro Polymers (China) Co., Ltd., with the mass ratio of the three being 2 / 1 / 1;

[0237] The film-forming solvent is 4.0 parts of diethylene glycol butyl ether, 1.0 parts of dipropylene glycol monobutyl ether, and 2.0 parts of ethylene glycol butyl ether;

[0238] The defoamer is 0.5 parts BYK 024 and 1.5 parts SURFYNOL 104BC defoamer;

[0239] The substrate wetting agent is TEGO Twin 4100 from BYK;

[0240] The rheological additives are 0.5 parts of ACRTSOL RM-998W and 0.5 parts of ACRTSOL RM-3030NPR;

[0241] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN 99DW(N) and TINUVIN 400DW(N) respectively.

[0242] The content of the polyisocyanate curing agent is 70 wt %, and the polyisocyanate curing agent is Asahi Kasei Duranate TLA100.

[0243] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:25, and the ratio of NCO (isocyanate group) to OH (hydroxyl group) is 1.3.

[0244] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0245] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, which is a coating-4 cup viscosity.

[0246] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0247] Example 5

[0248] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0249] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0250] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0251]

[0252] The amine curing agent is a water-based epoxy curing agent, and the solvent is pure water.

[0253] The water-based epoxy resin dispersion is the water-based epoxy emulsion XS0402 produced by Honghui New Materials Technology Co., Ltd., which has a solid content of 53%, a solid EEW of 480g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm; and the water-based epoxy emulsion EP387W produced by Allnex Resins (China) Co., Ltd., which has a solid content of 53%, a solid EEW of 490g / Ep, a viscosity of 1200mPa.S, and a particle size of 0.8-1μm; the ratio of the two emulsions is 1:1.

[0254] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0255] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0256] The dispersant is Additol VXW 6208;

[0257] The filler: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, mica powder GA-1;

[0258] The cosolvent is propylene glycol methyl ether and ethylene glycol butyl ether;

[0259] The defoamer is TEGO Airex 901W;

[0260] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0261] The content of the waterborne epoxy curing agent in the amine curing agent is 32wt%, and the waterborne epoxy curing agent is XS0608C of Honghui New Materials Technology Co., Ltd. and BECKOPOX of Allnex Resins (China) Co., Ltd. TM The mixture of EH613w / 80WA has a mass ratio of 1:1.

[0262] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:14, and the ratio of AHEW to EEW is 0.9.

[0263] Furthermore, the waterborne epoxy dispersion, pigments, fillers, dispersants, cosolvents and defoamers are ground to a fineness of less than 30 μm using a sand mill, and then substrate wetting agents and rheological additives are added in sequence under high-speed stirring conditions to obtain a uniformly mixed component A.

[0264] During construction, the cross-linkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0265] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0266] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0267]

[0268] The solvent of the polyisocyanate curing agent is propylene glycol diacetate (PGDA).

[0269] The aqueous hydroxylated acrylic resin dispersion is a product of Allnex Resins (China) Co., Ltd. A mixture of 6511, Antkote 2035 from Yantai Wanhua Chemical Group Co., Ltd. and Bayhydrol A 2542 from Covestro Polymers (China) Co., Ltd., with the mass ratio of the three being 2 / 1 / 1;

[0270] The film-forming solvent is 4.0 parts of diethylene glycol butyl ether, 1.0 parts of dipropylene glycol monobutyl ether, and 2.0 parts of ethylene glycol butyl ether;

[0271] The defoamer is 0.5 parts BYK 024 and 1.5 parts SURFYNOL 104BC defoamer;

[0272] The substrate wetting agent is TEGO Twin 4100 from BYK;

[0273] The rheological additives are 0.5 parts of ACRTSOL RM-998W and 0.5 parts of ACRTSOL RM-3030NPR;

[0274] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN 99DW(N) and TINUVIN 400DW(N) respectively;

[0275] The content of the polyisocyanate curing agent is 70 wt %, and the polyisocyanate curing agent is Asahi Kasei Duranate TLA100.

[0276] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:25, and the ratio of NCO (isocyanate group) to OH (hydroxyl group) is 1.3.

[0277] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0278] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, which is a coating-4 cup viscosity.

[0279] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0280] Example 6

[0281] In this embodiment, a fast-drying coating system is provided, comprising a fast-drying waterborne epoxy coating and a fast-drying waterborne polyurethane coating.

[0282] The quick-drying waterborne epoxy coating is formed from a first coating composition, which includes: a cross-linkable component (A) and an amine curing agent;

[0283] The crosslinkable component (A) is composed of the following components in terms of mass percentage:

[0284]

[0285] The amine curing agent is a water-based epoxy curing agent, and the solvent is pure water.

[0286] The water-based epoxy resin dispersion is a water-based epoxy emulsion model PZ3961-1 produced by Huntsman Chemical Co., Ltd., which has a solid content of 53%, a solid EEW of 490g / Ep, a viscosity of 1000mPa.S, and a particle size of 0.8-1μm; and a water-based epoxy emulsion model EP387W produced by Allnex Resins (China) Co., Ltd., which has a solid content of 53%, a solid EEW of 490g / Ep, a viscosity of 1200mPa.S, and a particle size of 0.8-1μm; the ratio of the two emulsions is 1:1.

[0287] The pigments are TI-PURE R-996 titanium dioxide and YZ 1688 iron oxide yellow;

[0288] The anti-rust pigments are 409 zinc sulfate and CLF102 aluminum tripolyphosphate;

[0289] The dispersant is Additol VXW 6208;

[0290] The filler: feldspar powder PGf-7, barite powder B45, 800 mesh talc powder, mica powder GA-1;

[0291] The cosolvent is propylene glycol methyl ether and ethylene glycol butyl ether;

[0292] The defoamer is TEGO Airex 901W;

[0293] The substrate wetting agent is BYK 345 from BYK and TEGO Twin 4100 from Evonik.

[0294] In the amine curing agent, the content of the waterborne epoxy curing agent is 43wt%, and the waterborne epoxy curing agent is Aradur 38-1 of Huntsman Co., Ltd. and BECKOPOX TM Mix of EH 613w / 80WA, mass ratio is 1:1.

[0295] The mass ratio of the crosslinkable component (A) to the amine curing agent is 100:14, and the ratio of AHEW to EEW is 0.9.

[0296] Furthermore, the water-based epoxy dispersion, pigments, fillers, dispersants, cosolvents, and defoamers are ground to a fineness of less than 30 μm using a sand mill, and then substrate wetting agents and rheological additives are added in sequence under high-speed stirring conditions to obtain the crosslinkable component (A) that is evenly mixed.

[0297] During construction, the cross-linkable component (A) and the amine curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, wherein the viscosity is a coating-4 cup viscosity.

[0298] The quick-drying waterborne polyurethane coating is formed from a second coating composition, which comprises: a cross-linkable component (B) and a polyisocyanate curing agent;

[0299] The crosslinkable component (B) is composed of the following components in terms of mass percentage:

[0300]

[0301] The solvent of the polyisocyanate curing agent is propylene glycol diacetate (PGDA).

[0302] The aqueous hydroxylated acrylic resin dispersion is a product of Allnex Resins (China) Co., Ltd. A mixture of 6511, Antkote 2035 from Yantai Wanhua Chemical Group Co., Ltd. and Bayhydrol A 2542 from Covestro Polymers (China) Co., Ltd., with the mass ratio of the three being 2 / 1 / 1;

[0303] The film-forming solvent is 4.0 parts of diethylene glycol butyl ether, 1.0 parts of dipropylene glycol monobutyl ether, and 2.0 parts of ethylene glycol butyl ether;

[0304] The defoamer is 0.5 parts BYK 024 and 1.5 parts SURFYNOL 104BC defoamer;

[0305] The substrate wetting agent is TEGO Twin 4100 from BYK;

[0306] The rheological additives are 0.5 parts of ACRTSOL RM-998W and 0.5 parts of ACRTSOL RM-3030NPR;

[0307] The ultraviolet light absorber and the hindered amine light stabilizer are TINUVIN 99DW(N) and TINUVIN 400DW(N) respectively.

[0308] The content of the polyisocyanate curing agent is 70 wt %, and the polyisocyanate curing agent is Asahi Kasei Duranate TLA100.

[0309] The mass ratio of the crosslinkable component (B) to the polyisocyanate curing agent is 100:25, and the ratio of NCO (isocyanate group) to OH (hydroxyl group) is 1.3.

[0310] Furthermore, the aqueous hydroxy acrylic resin dispersion, pigment, dispersant, film-forming solvent, and defoamer are ground to a fineness of less than 10 μm using a sand mill, and then a substrate wetting agent, a rheological additive, an ultraviolet light absorber, and a hindered amine light stabilizer are added in sequence under high-speed stirring conditions to obtain the cross-linkable component (B) that is evenly mixed.

[0311] During construction, the crosslinkable component (B) and the polyisocyanate curing agent are mixed evenly and diluted with water to a viscosity of 15-40s, which is a coating-4 cup viscosity.

[0312] The construction properties and appearance of the quick-drying water-based two-component epoxy coating and water-based two-component polyurethane coating are shown in Tables 1 and 2. The evaluation method for bubble burst is as follows: the epoxy coating is sprayed with a Sata JET5000 upper pot gun (1.8mm diameter), the flash-drying time between spraying passes is 1 minute, the leveling time is 15 minutes, and the film thickness of the epoxy coating is 30-50μm. The polyurethane coating is sprayed in the same way, leveled for 15 minutes, and then placed in a 60-degree oven for 40 minutes.

[0313] Comparative Example 1

[0314] Example 1 was repeated, except that in the crosslinkable component (B), the hydroxy acrylic resin was XK-540 resin; other conditions remain unchanged and the test is carried out according to the method of the above embodiment.

[0315] Comparative Example 2

[0316] Example 1 was repeated, except that the polyisocyanate curing agent was DIC's BURNOCK DNW-5500, and other conditions remained unchanged, and the test was carried out according to the method of the above example.

[0317] Comparative Example 3

[0318] Example 3 was repeated, except that in the crosslinkable component (A), the waterborne epoxy resin dispersion was STW703A waterborne epoxy emulsion produced by Huayi Chemical. The remaining conditions remained unchanged, and the test was carried out according to the method of the above example.

[0319] Comparative Example 4

[0320] Example 3 was repeated, except that the amine curing agent was BECKOPOXE H616w / 67WA produced by Allnex Resins (China) Co., Ltd. The other conditions remained unchanged, and the test was carried out according to the method of the above example.

[0321] In the above embodiments and comparative examples of the present invention, the test performance substrate used is an SPCC steel plate, which is then coated with a water-based epoxy coating, dried for 30 minutes, baked at 80°C for 2 hours, and placed at room temperature for 7 days before testing the performance. The performance is shown in Table 2.

[0322] Table 1

[0323]

[0324]

[0325] It can be seen from the experimental results in Table 1 that, relative to the currently commercially available polyurethane coating samples (Comparative Example 1 and Comparative Example 2), the quick-drying waterborne polyurethane coating provided by the embodiment of the present invention has a high bubble-bursting film thickness under high temperature and low humidity, high temperature and high humidity, low temperature and low humidity, and low temperature and high humidity conditions. Relative to the currently commercially available epoxy coating (Comparative Example 3 and Comparative Example 4), the present invention discloses a quick-drying waterborne epoxy coating (dry film thickness of about 30-50 μm) which is sprayed for 15 minutes under four different temperature and humidity conditions and then surface-dry, and then a quick-drying waterborne polyurethane coating can be sprayed. It can be seen that the quick-drying coating system composed of a quick-drying waterborne epoxy coating and a quick-drying waterborne polyurethane coating provided by the present application has good construction properties under high temperature and low humidity, high temperature and high humidity, low temperature and low humidity, and low temperature and high humidity conditions.

[0326] Table 2

[0327]

[0328]

[0329] As shown in Table 2, relative to the currently commercially available polyurethane coating samples (Comparative Example 1 and Comparative Example 2), the quick-drying waterborne polyurethane coating provided by the present invention has good water resistance and acid and alkali resistance, and has the characteristics of high gloss. Under baking conditions, the gloss of the quick-drying waterborne polyurethane coating of the present invention is 5 points higher than that of the commercially available ones. This is related to the reaction speed and cross-linking density of the hydroxypropyl resin and the curing agent in the polyurethane. Comparison of Comparative Example 3 with Comparative Example 4 shows that the epoxy resin and the amine curing agent in the epoxy coating have a great influence on the performance and gloss of the composite coating. This may be related to the drying properties of the epoxy resin and the amine curing agent, that is, the slow-drying epoxy resin and the amine curing agent will affect the reaction of NCO / OH in the polyurethane coating, and there will be obvious mixed layers between the epoxy coating and the polyurethane coating, thereby affecting the performance and reducing the gloss. The quick-drying waterborne epoxy coating of the present invention has the characteristics of quick drying, and has little effect on the reaction of NCO / OH in the quick-drying waterborne polyurethane coating, so the characteristics of high cross-linking density, high gloss and high resistance of the quick-drying waterborne polyurethane coating can be maintained. The quick-drying coating system provided by the present application, which is composed of a quick-drying waterborne epoxy coating and a quick-drying waterborne polyurethane coating, has a high-gloss, high-brightness paint film appearance, and the dry film has good durability.

[0330] It can also be seen from Table 1 and Table 2 that the quick-drying coating system composed of the quick-drying waterborne epoxy coating and the quick-drying waterborne polyurethane coating provided by the present invention has wide construction applicability and high gloss. Under the conditions of self-drying and low-temperature baking, it has the characteristics of high gloss and is suitable for various industries such as locomotives, machinery and equipment, steel structures and wooden furniture.

[0331] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A quick-drying water-based coating system, comprising at least one first coating layer and at least one second coating layer, characterized in that: The first coating layer is formed from a first coating composition, and the second coating layer is formed from a second coating composition; wherein, The first coating composition comprises: a cross-linkable component (A) and an amine curing agent; The second coating composition comprises: a crosslinkable component (B) and a polyisocyanate curing agent; The crosslinkable component (A) comprises: an aqueous epoxy resin dispersion, wherein the aqueous epoxy resin dispersion is selected from one or a mixture of the aqueous epoxy emulsion XS0402 of Honghui New Materials Technology Co., Ltd., the aqueous epoxy emulsion model PZ3961-1 of Huntsman Chemical Co., Ltd., and the aqueous epoxy emulsion model EP387W of Allnex Resins (China) Co., Ltd.; and, The cross-linkable component (B) comprises: an aqueous hydroxy acrylic resin dispersion, wherein the aqueous hydroxy acrylic resin dispersion is selected from the aqueous hydroxy acrylic resin of model Bayhydrol A 2601 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxy acrylic resin of model Bayhydrol A 145 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxy acrylic resin of model Bayhydrol A 2542 of Covestro Polymers (China) Co., Ltd., the aqueous hydroxy acrylic resin of model SETAQUA 6511 of Allnex Resins (China) Co., Ltd., and the aqueous hydroxy acrylic resin of model Antkote2035 of Yantai Wanhua, or a mixture of several thereof; The amine curing agent is an aqueous solution of a modified alicyclic polyamine adduct; The polyisocyanate curing agent is one of Asahi Kasei's Duranate TLA100 and Duranate TUL-100, or one of Covestro Polymers (China) Co., Ltd.'s Desmodur N 3900 and Desmodur 3600.

2. The quick-drying water-based coating system according to claim 1, characterized in that: The mass ratio of the cross-linkable component (A) to the amine curing agent is 100:(10-20).

3. The quick-drying water-based coating system according to claim 1, characterized in that: The crosslinkable component (A) further comprises an anti-rust pigment, and the anti-rust pigment is selected from at least one of a composite hybrid phosphate anti-rust pigment and a composite molybdate anti-rust pigment.

4. The quick-drying water-based coating system according to claim 1, characterized in that: The crosslinkable component (A) further comprises a cosolvent, which is selected from at least one or more mixtures of propylene glycol methyl ether, propylene glycol phenyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

5. The quick-drying water-based coating system according to claim 1, characterized in that: The ratio of the NCO group of the polyisocyanate curing agent to the OH group of the crosslinkable component (B) is (1-1.5):

1.

6. The quick-drying water-based coating system according to claim 1, characterized in that: The crosslinkable component (B) further comprises a film-forming solvent, and the film-forming solvent is selected from at least one or more mixtures of ethylene glycol butyl ether, diethylene glycol butyl ether, diethylene glycol ethyl ether acetate, diethylene glycol hexyl ether, diethylene glycol diethyl ether, propylene glycol diacetate, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether solvents.

7. The quick-drying water-based coating system according to any one of claims 1 to 6, characterized in that: At least one of the cross-linkable component (A) or the cross-linkable component (B) further comprises a filler, and the filler is selected from at least one of talc powder, feldspar powder, barite powder, precipitated barium sulfate, and mica powder.

8. The quick-drying water-based coating system according to claim 7, characterized in that: At least one of the crosslinkable component (A) or the crosslinkable component (B) further comprises an auxiliary agent, wherein the auxiliary agent is selected from at least one of a dispersant, a defoamer, a substrate wetting agent, a rheological additive, and a pigment.

9. The quick-drying water-based coating system according to claim 7, characterized in that: The crosslinkable component (B) further comprises at least one of an ultraviolet light absorber or a hindered amine light stabilizer.

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