Temperature and humidity alternating resistant water-based paint and preparation method thereof

Abstract

The invention provides a temperature and humidity alternating resistant water-based paint and a preparation method thereof. The temperature and humidity alternating resistant water-based paint is composed of a component A and a component B, the component A comprises an elastic emulsion, an anti-freezing agent, a coalescing agent, a wetting dispersant, a defoaming agent, a thickening agent, a multifunctional additive, water and at least one of glass fibers, high silica fibers and sepiolite fibers; the component B comprises a cross-linking agent; the cross-linking agent is an isocyanate curing agent, an oxazoline cross-linking agent or an aziridine cross-linking agent. According to the temperature and humidity alternating resistant water-based paint provided by the invention, components with specific contents are adopted, so that relatively good overall interaction is realized, and a coating can have good stability in a complex temperature and humidity change environment; and the component A can also comprise a fireproof filler and a flame retardant, can expand and foam when meeting flames to form a foam expansion layer, has high strength and compactness, can prevent flame heat transmission and prolong the fire endurance of the base material, and has good fire resistance.

Description

[0001] The present application is a divisional application of a patent application with the application date of July 8, 2022, the application number of 202210799523.1, and the invention name of a temperature and humidity alternating resistant water-based fireproof coating and a preparation method thereof. TECHNICAL FIELD

[0002] The present application relates to the technical field of water-based intumescent fireproof coating, more specifically, to a temperature and humidity alternating resistant water-based fireproof coating and a preparation method thereof, which is specifically used for fireproofing requirements of buildings, bridges, offshore equipment, rail transit vehicles, new energy, etc. BACKGROUND

[0003] Intumescent fireproof coating is a functional coating with properties of fireproofing, flame retardation, heat insulation, decoration, etc. When a fire occurs, the coating forms a carbonized layer with flame-retardant and heat-insulating effects through foaming and expansion when exposed to fire, which can improve the fire resistance of the substrate and prolong the disaster resistance time of the substrate for a certain period of time.

[0004] Intumescent fireproof coating can be divided into oil-based fireproof coating and water-based fireproof coating according to the different dispersion media. Among them, water-based fireproof coating uses water as the dispersion medium, has very low volatile organic compound content, is green and environmentally friendly, and does not have the problems of environmental protection and flammability and explosion that are common in oil-based fireproof coating, is safe to use, and has a wide application prospect in the fields of rail vehicles, ships, aviation, buildings, household appliances, etc. Moreover, under the current serious air pollution environment, it is an inevitable trend for water-based fireproof coating to replace traditional oil-based fireproof coating in the future.

[0005] According to the requirements of GB 14907-2018 Steel Structure Fireproof Coating Technical Conditions, intumescent coating can be divided into indoor fireproof coating and outdoor fireproof coating. Among them, outdoor fireproof coating has higher demands on the comprehensive performance of the material. Not only does the coating have excellent fire resistance, but also the adhesion, temperature change resistance, humidity resistance, medium resistance, etc. of the coating are also subject to corresponding standard requirements. In order to ensure the fire resistance of the coating, it is often necessary to appropriately increase the fireproof filler, and the color base ratio of the system is too high, the medium resistance and mechanical properties of the coating are poor, and when the coating is exposed to an environment with high humidity and large temperature difference, cracking, peeling, and skinning may occur. At present, there have been many reports on the research of intumescent water-based fireproof coating. The focus of the research is mostly on the fire resistance of the coating itself, and the related products on the market are mostly used for indoor fireproofing. There are few reports on the application and solution of outdoor high-performance intumescent water-based fireproof coating.

[0006] Therefore, it is of great significance to develop a water-based fireproof coating that has high and low temperature resistance, humidity resistance, stable properties during curing and use, is not prone to cracking, and has good fire resistance. SUMMARY

[0007] In view of this, the purpose of this invention is to provide a water-based fire-retardant coating resistant to alternating temperature and humidity and its preparation method. The water-based fire-retardant coating resistant to alternating temperature and humidity provided by this invention is stable in properties and not prone to cracking during curing and use. The coating can have good stability in complex temperature and humidity environments. Furthermore, it can expand and foam when exposed to flames to form a foam expansion layer. The expansion layer has high strength and density, which can prevent the transfer of heat from the flame, extend the fire resistance limit of the substrate, and has good fire resistance performance.

[0008] This invention provides a temperature and humidity resistant water-based fire-retardant coating, which is composed of component A and component B;

[0009] Component A includes:

[0010] 25-55 parts by weight of elastic emulsion;

[0011] 70-100 parts by weight of fire-retardant filler;

[0012] Flame retardant 3-11 parts by weight;

[0013] Antifreeze 1-4 parts by weight;

[0014] Refractory fiber 2-6 parts by weight;

[0015] 1-4 parts by weight of film-forming aid;

[0016] Wetting and dispersing agent: 0.1-3 parts by weight;

[0017] Defoamer 0.1~3 parts by weight;

[0018] Thickener 0.1~3 parts by weight;

[0019] Multifunctional additive, 0.1-2 parts by weight;

[0020] 2-11 parts by weight of water;

[0021] Component B includes:

[0022] 1-10 parts by weight of crosslinking agent; the crosslinking agent is an isocyanate curing agent, an oxazoline crosslinking agent, or a aziridine crosslinking agent.

[0023] Preferably, the elastic emulsion is selected from one or more of styrene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, vinyl acetate-acrylic emulsion, and waterborne polyurea emulsion.

[0024] Preferably, the fire-retardant filler is composed of ammonium polyphosphate, melamine, pentaerythritol, titanium dioxide and expandable graphite in a mass ratio of (20~30):(16~20):(18~24):(12~20):(2~6).

[0025] Preferably, the flame retardant is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; and the antifreeze is propylene glycol.

[0026] Preferably, the refractory fiber is selected from one or more of glass fiber, high silica fiber and sepiolite fiber.

[0027] Preferably, the film-forming aid is selected from one or more of dodecyl alcohol ester, propylene glycol butyl ether, and dipropylene glycol methyl ether.

[0028] Preferably, the wetting and dispersing agent is selected from one or more of sodium polycarboxylate, polymeric alkyl alcohol ammonium salt, and acrylate copolymer ammonium salt.

[0029] Preferably, the thickener is selected from one or more of acrylic thickeners, polyurethane thickeners, and fumed silica.

[0030] Preferably, the multifunctional additive is 2-amino-2-methyl-1-propanol.

[0031] This invention also provides a method for preparing the temperature and humidity resistant water-based fire-retardant coating described above, comprising the following steps:

[0032] a) Mix the elastic emulsion, antifreeze, film-forming aid and water evenly, then add the wetting and dispersing agent, defoamer, multifunctional aid, flame retardant and refractory fiber in sequence, and stir at low speed of 300 rpm to 500 rpm for 5 min to 15 min to obtain the slurry;

[0033] b) Add fire-retardant filler to the above slurry and stir at high speed of 1000 rpm to 1500 rpm for 30 min to 60 min to obtain a mixed slurry;

[0034] c) Add a thickener to the above mixed slurry and disperse at 800 rpm to 1000 rpm for 10 min to 30 min to obtain component A;

[0035] d) Mix the above components A and B evenly to obtain a water-based fire-retardant coating resistant to temperature and humidity alternation.

[0036] This invention provides a temperature and humidity resistant water-based fire-retardant coating, composed of component A and component B. Component A includes: 25-55 parts by weight of elastic emulsion; 70-100 parts by weight of fire-retardant filler; 3-11 parts by weight of flame retardant; 1-4 parts by weight of antifreeze; 2-6 parts by weight of refractory fiber; 1-4 parts by weight of film-forming aid; 0.1-3 parts by weight of wetting and dispersing agent; 0.1-3 parts by weight of defoamer; 0.1-3 parts by weight of thickener; 0.1-2 parts by weight of multifunctional additive; and 2-11 parts by weight of water. Component B includes: 1-10 parts by weight of crosslinking agent; the crosslinking agent is an isocyanate curing agent, an oxazoline crosslinking agent, or a aziridine crosslinking agent. Compared with the prior art, the temperature and humidity resistant water-based fireproof coating provided by the present invention uses specific content components to achieve better overall interaction. It is stable and not easy to crack during curing and use. The coating can have good stability in complex temperature and humidity environments. Furthermore, it can expand and foam when exposed to flames to form a foam expansion layer. The expansion layer has high strength and density, which can prevent the heat transfer of the flame, extend the fire resistance limit of the substrate, and has good fire resistance performance.

[0037] In addition, the preparation method provided by this invention uses readily available raw materials, is simple to operate, and operates under mild conditions, thus having broad application prospects. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] This invention provides a temperature and humidity resistant water-based fire-retardant coating, which is composed of component A and component B;

[0040] Component A includes:

[0041] 25-55 parts by weight of elastic emulsion;

[0042] 70-100 parts by weight of fire-retardant filler;

[0043] Flame retardant 3-11 parts by weight;

[0044] Antifreeze 1-4 parts by weight;

[0045] Refractory fiber 2-6 parts by weight;

[0046] 1-4 parts by weight of film-forming aid;

[0047] Wetting and dispersing agent: 0.1-3 parts by weight;

[0048] Defoamer 0.1~3 parts by weight;

[0049] Thickener 0.1~3 parts by weight;

[0050] Multifunctional additive, 0.1-2 parts by weight;

[0051] 2-11 parts by weight of water;

[0052] Component B includes:

[0053] 1-10 parts by weight of crosslinking agent; the crosslinking agent is an isocyanate curing agent, an oxazoline crosslinking agent, or a aziridine crosslinking agent.

[0054] The main purpose of this invention is to improve the impact resistance of water-based fire-retardant coatings under complex temperature and humidity conditions, preventing cracking, peeling, and flaking when exposed to environments with large temperature and humidity differences. Most existing fire-retardant coatings on the market are solvent-based. While solvent-based fire-retardant coatings still have significant advantages in overall performance and a wider range of applications compared to water-based fire-retardant coatings, with the advancement and implementation of national environmental protection policies, water-based fire-retardant coatings replacing traditional oil-based fire-retardant coatings is an inevitable trend for future development. Currently, most water-based fire-retardant coating products and research reports on the market indicate that due to their generally limited overall performance, they are mostly only suitable for indoor fire prevention and other ordinary environments. When facing environments with complex temperature and humidity variations, water-based fire-retardant coatings offer no advantage.

[0055] This invention provides a temperature and humidity resistant water-based fire-retardant coating, which consists of component A and component B, i.e., a two-component water-based fire-retardant coating.

[0056] In this invention, component A comprises:

[0057] 25-55 parts by weight of elastic emulsion;

[0058] 70-100 parts by weight of fire-retardant filler;

[0059] Flame retardant 3-11 parts by weight;

[0060] Antifreeze 1-4 parts by weight;

[0061] Refractory fiber 2-6 parts by weight;

[0062] 1-4 parts by weight of film-forming aid;

[0063] Wetting and dispersing agent: 0.1-3 parts by weight;

[0064] Defoamer 0.1~3 parts by weight;

[0065] Thickener 0.1~3 parts by weight;

[0066] Multifunctional additive, 0.1-2 parts by weight;

[0067] 2-11 parts by weight of water;

[0068] Preferably composed of the following components:

[0069] 30-50 parts by weight of elastic emulsion;

[0070] 77-94 parts by weight of fire-retardant filler;

[0071] 5-10 parts by weight of flame retardant;

[0072] 2-3 parts by weight of antifreeze;

[0073] 3-5 parts by weight of refractory fiber;

[0074] 2-3 parts by weight of film-forming aid;

[0075] 0.5 to 2 parts by weight of wetting and dispersing agent;

[0076] Defoamer 0.5~2 parts by weight;

[0077] Thickener 0.8~2 parts by weight;

[0078] Multifunctional additive, 0.2~1 parts by weight;

[0079] 3 to 10 parts by weight of water.

[0080] In this invention, the elastic emulsion is preferably selected from one or more of styrene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, vinyl acetate-acrylic emulsion, and waterborne polyurea emulsion, more preferably styrene-acrylic emulsion, silicone-acrylic emulsion, vinyl acetate-acrylic emulsion, or waterborne polyurea emulsion. This invention does not impose any special restrictions on the source of the elastic emulsion; commercially available products well-known to those skilled in the art can be used.

[0081] In this invention, the fire-retardant filler is preferably composed of ammonium polyphosphate, melamine, pentaerythritol, titanium dioxide, and expandable graphite in a mass ratio of (20~30):(16~20):(18~24):(12~20):(2~6). This invention does not impose any special restrictions on the source of the ammonium polyphosphate, melamine, pentaerythritol, titanium dioxide, and expandable graphite in the fire-retardant filler; commercially available products well-known to those skilled in the art can be used.

[0082] In this invention, the flame retardant is preferably 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO); the antifreeze is preferably propylene glycol; both are commercially available products well known to those skilled in the art.

[0083] In this invention, the refractory fiber is preferably selected from one or more of glass fiber, high-silica fiber, and sepiolite fiber, and more preferably glass fiber or high-silica fiber. This invention does not impose any special restrictions on the source of the refractory fiber; commercially available products well-known to those skilled in the art can be used.

[0084] In this invention, the film-forming aid is preferably selected from one or more of dodecyl alcohol ester, propylene glycol butyl ether, and dipropylene glycol methyl ether, and more preferably dodecyl alcohol ester. This invention does not impose any particular limitation on the source of the film-forming aid; commercially available products well-known to those skilled in the art can be used.

[0085] In this invention, the wetting and dispersing agent is preferably selected from one or more of sodium polycarboxylate, polymeric alkyl alcohol ammonium salt, and acrylate copolymer ammonium salt, more preferably sodium polycarboxylate. This invention does not impose any particular limitation on the source of the wetting and dispersing agent; commercially available products well known to those skilled in the art can be used.

[0086] In this invention, the defoamer is preferably selected from nonionic polysiloxane defoamers and / or mineral oil defoamers, more preferably nonionic polysiloxane defoamers. This invention does not impose any special restrictions on the source of the defoamer; commercially available products well-known to those skilled in the art can be used.

[0087] In this invention, the thickener is preferably selected from one or more of acrylic thickeners, polyurethane thickeners, and fumed silica, more preferably from one or two of acrylic thickeners, polyurethane thickeners, and fumed silica; wherein the acrylic thickener includes acrylate thickeners and acrylic thickeners. This invention does not impose any special restrictions on the source of the thickener; commercially available products well known to those skilled in the art can be used.

[0088] In this invention, the multifunctional additive is preferably 2-amino-2-methyl-1-propanol (AMP-95); it is mostly used in aqueous systems and has functions such as wetting and dispersing, pH adjustment, and corrosion reduction. Commercially available products well known to those skilled in the art can be used.

[0089] The present invention does not impose any special restrictions on the water used; deionized water, which is well known to those skilled in the art, can be used.

[0090] In this invention, component B comprises:

[0091] 1-10 parts by weight of crosslinking agent;

[0092] Preferred options are:

[0093] Crosslinking agent 2.5~9.5 parts by weight.

[0094] In this invention, the crosslinking agent is an isocyanate curing agent, an oxazoline crosslinking agent, or a aziridine crosslinking agent. This invention does not have any particular restrictions on the source of the crosslinking agent; commercially available products well-known to those skilled in the art can be used. This invention selects the aforementioned specific types of crosslinking agents to improve the chemical crosslinking properties of the coating through chemical crosslinking. This post-crosslinking enables the coating to form a dense network structure, effectively blocking moisture and simultaneously improving the mechanical strength of the coating. Combined with fire-retardant fibers, it provides the coating with excellent mechanical properties.

[0095] The temperature and humidity resistant water-based fire-retardant coating provided by this invention is a green and environmentally friendly intumescent fire-retardant coating. When the coating is exposed to fire, it expands through foaming to form a carbonized layer with flame-retardant and heat-insulating effects. No harmful gases are produced during the expansion process. It can improve the fire resistance of the substrate and extend the substrate's disaster resistance time for a certain period of time. The coating still has good stability in complex environments with alternating temperature and humidity. Compared with single-component water-based fire-retardant coatings, its comprehensive performance has significant advantages in impact resistance, flexibility, resistance to media, and resistance to high and low temperature impacts, in addition to its excellent fire-retardant performance.

[0096] This invention also provides a method for preparing the temperature and humidity resistant water-based fire-retardant coating described above, comprising the following steps:

[0097] a) Mix the elastic emulsion, antifreeze, film-forming aid and water evenly, then add the wetting and dispersing agent, defoamer, multifunctional aid, flame retardant and refractory fiber in sequence, and stir at low speed of 300 rpm to 500 rpm for 5 min to 15 min to obtain the slurry;

[0098] b) Add fire-retardant filler to the above slurry and stir at high speed of 1000 rpm to 1500 rpm for 30 min to 60 min to obtain a mixed slurry;

[0099] c) Add a thickener to the above mixed slurry and disperse at 800 rpm to 1000 rpm for 10 min to 30 min to obtain component A;

[0100] d) Mix the above components A and B evenly to obtain a water-based fire-retardant coating resistant to temperature and humidity alternation.

[0101] The present invention first prepares a slurry by mixing elastic emulsion, antifreeze, film-forming aid and water evenly, then adding wetting and dispersing agent, defoamer, multifunctional aid, flame retardant and refractory fiber in sequence, and stirring at low speed at 300 rpm to 500 rpm for 5 min to 15 min to obtain the slurry.

[0102] In this invention, the elastic emulsion, antifreeze, film-forming aid, water, wetting and dispersing agent, defoamer, multifunctional additive, flame retardant and refractory fiber are the same as those in the above technical solution, and will not be repeated here.

[0103] After obtaining the slurry, the present invention mixes the slurry with filler, specifically by adding fire-retardant filler to the slurry and stirring at high speed at 1000rpm~1500rpm for 30min~60min to obtain a mixed slurry.

[0104] In this invention, the fireproof filler is the same as that in the above technical solution, and will not be described again here; at the same time, this invention adopts the method of adding each component of the fireproof filler into the slurry one by one, which can avoid the problem of large dust flying due to pre-mixing.

[0105] After obtaining the mixed slurry, the present invention adjusts the consistency by adding a thickener to the mixed slurry and dispersing it at 800 rpm to 1000 rpm for 10 min to 30 min to obtain component A.

[0106] In this invention, the thickener is the same as that in the above technical solution, and will not be described again here; this invention uses the above thickener to adjust the consistency of the system and obtain component A.

[0107] Finally, the present invention mixes the above-mentioned component A and component B evenly to obtain a water-based fire-retardant coating resistant to temperature and humidity alternation.

[0108] In this invention, all steps of the above preparation method can be carried out under greenhouse conditions, and there are no special restrictions on this.

[0109] The preparation method provided by this invention uses readily available raw materials, is simple to operate, and operates under mild conditions, thus having broad application prospects.

[0110] This invention provides a temperature and humidity resistant water-based fire-retardant coating, composed of component A and component B. Component A includes: 25-55 parts by weight of elastic emulsion; 70-100 parts by weight of fire-retardant filler; 3-11 parts by weight of flame retardant; 1-4 parts by weight of antifreeze; 2-6 parts by weight of refractory fiber; 1-4 parts by weight of film-forming aid; 0.1-3 parts by weight of wetting and dispersing agent; 0.1-3 parts by weight of defoamer; 0.1-3 parts by weight of thickener; 0.1-2 parts by weight of multifunctional additive; and 2-11 parts by weight of water. Component B includes: 1-10 parts by weight of crosslinking agent; the crosslinking agent is an isocyanate curing agent, an oxazoline crosslinking agent, or a aziridine crosslinking agent. Compared with the prior art, the temperature and humidity resistant water-based fireproof coating provided by the present invention uses specific content components to achieve better overall interaction. It is stable and not easy to crack during curing and use. The coating can have good stability in complex temperature and humidity environments. Furthermore, it can expand and foam when exposed to flames to form a foam expansion layer. The expansion layer has high strength and density, which can prevent the heat transfer of the flame, extend the fire resistance limit of the substrate, and has good fire resistance performance.

[0111] In addition, the preparation method provided by this invention uses readily available raw materials, is simple to operate, and operates under mild conditions, thus having broad application prospects.

[0112] To further illustrate the present invention, the following embodiments are provided for detailed description. All raw materials used in the following embodiments of the present invention are commercially available products.

[0113] Example 1

[0114] (1) Preparation of slurry: Mix 30 parts by weight of styrene-acrylic emulsion, 2 parts by weight of propylene glycol, 2 parts by weight of dodecyl alcohol ester and 10 parts by weight of deionized water evenly, and then add 0.5 parts by weight of sodium polycarboxylate, 0.5 parts by weight of nonionic polysiloxane defoamer, 0.5 parts by weight of AMP-95, 5 parts by weight of DOPO and 3 parts by weight of glass fiber in sequence. Stir at low speed for 10 minutes at room temperature and 400 rpm to obtain slurry.

[0115] (2) Mixing of filler and slurry: 24 parts by weight of ammonium polyphosphate, 16 parts by weight of melamine, 18 parts by weight of pentaerythritol, 4 parts by weight of expandable graphite and 15 parts by weight of titanium dioxide were added to the above slurry in sequence, and the mixture was stirred at high speed at 1200 rpm for 45 min at room temperature to obtain a mixed slurry.

[0116] (3) Consistency adjustment: First, add 0.5 parts by weight of acrylate thickener to the above mixed slurry to adjust the consistency of the system, then add 1 part by weight of fumed silica, stir and disperse at room temperature and 900 rpm for 20 min to obtain component A.

[0117] (4) Mix the above component A and component B (aziridine crosslinking agent) at a mass ratio of 98:2 to obtain a water-based fireproof coating resistant to temperature and humidity alternation.

[0118] Example 2

[0119] (1) Preparation of slurry: Mix 45 parts by weight of vinyl acetate emulsion, 3 parts by weight of propylene glycol, 3 parts by weight of dodecyl alcohol ester and 8 parts by weight of deionized water evenly, then add 1 part by weight of sodium polycarboxylate, 1 part by weight of nonionic polysiloxane defoamer, 1 part by weight of AMP-95, 6 parts by weight of DOPO and 5 parts by weight of high silica fiber in sequence, and stir at low speed for 10 minutes at 400 rpm to obtain slurry.

[0120] (2) Mixing of filler and slurry: 28 parts by weight of ammonium polyphosphate, 18 parts by weight of melamine, 20 parts by weight of pentaerythritol, 6 parts by weight of expandable graphite and 12 parts by weight of titanium dioxide were added to the above slurry in sequence, and the mixture was stirred at high speed of 1200 rpm for 45 min to obtain a mixed slurry.

[0121] (3) Consistency adjustment: First, add 0.5 parts by weight of polyurethane thickener to the above mixed slurry to adjust the consistency of the system, then add 0.3 parts by weight of acrylic thickener, stir and disperse at 900 rpm for 20 min to obtain component A.

[0122] (4) Mix the above component A and component B (oxazoline crosslinking agent) at a mass ratio of 97:3 to obtain a water-based fireproof coating resistant to temperature and humidity alternation.

[0123] Example 3

[0124] (1) Preparation of slurry: Mix 35 parts by weight of silicone acrylic emulsion, 2 parts by weight of propylene glycol, 2 parts by weight of dodecyl alcohol ester and 10 parts by weight of deionized water evenly, then add 0.5 parts by weight of sodium polycarboxylate, 0.5 parts by weight of nonionic polysiloxane defoamer, 0.5 parts by weight of AMP-95, 5 parts by weight of DOPO and 3 parts by weight of glass fiber in sequence, and stir at low speed at 400 rpm for 10 min to obtain slurry.

[0125] (2) Mixing of filler and slurry: 26 parts by weight of ammonium polyphosphate, 20 parts by weight of melamine, 22 parts by weight of pentaerythritol, 5 parts by weight of expandable graphite and 12 parts by weight of titanium dioxide were added to the above slurry in sequence, and the mixture was stirred at high speed of 1200 rpm for 45 min to obtain a mixed slurry.

[0126] (3) Consistency adjustment: Add 2 parts by weight of acrylate thickener to the above mixed slurry to adjust the consistency of the system, stir and disperse at 900 rpm for 20 min to obtain component A.

[0127] (4) Mix the above component A and component B (aziridine crosslinking agent) at a mass ratio of 98:2 to obtain a water-based fireproof coating resistant to temperature and humidity alternation.

[0128] Example 4

[0129] (1) Preparation of slurry: Mix 50 parts by weight of waterborne polyurea emulsion, 3 parts by weight of propylene glycol, 3 parts by weight of dodecyl alcohol ester and 3 parts by weight of deionized water evenly, then add 2 parts by weight of sodium polycarboxylate, 2 parts by weight of nonionic polysiloxane defoamer, 0.2 parts by weight of AMP-95, 10 parts by weight of DOPO and 5 parts by weight of glass fiber in sequence, and stir at low speed at 400 rpm for 10 min to obtain slurry.

[0130] (2) Mixing of filler and slurry: 30 parts by weight of ammonium polyphosphate, 18 parts by weight of melamine, 24 parts by weight of pentaerythritol, 2 parts by weight of expandable graphite and 20 parts by weight of titanium dioxide are added to the above slurry in sequence, and the mixture is stirred at high speed of 1200 rpm for 45 min to obtain a mixed slurry.

[0131] (3) Consistency adjustment: Add 2 parts by weight of fumed silica to the above mixed slurry, stir and disperse at 900 rpm for 20 min to obtain component A.

[0132] (4) Mix the above component A and component B (isocyanate curing agent) at a mass ratio of 95:5 to obtain a water-based fireproof coating resistant to temperature and humidity alternation.

[0133] Samples of the temperature and humidity resistant water-based fire retardant coatings (2mm dry film) prepared in Examples 1-4 and commercially available water-based fire retardant coatings (Henan Lianfang) were prepared according to the requirements of GB 14907-2018 and their performance was tested. The test results are shown in Table 1.

[0134] Table 1. Performance data of the temperature and humidity resistant waterborne fire retardant coatings prepared in Examples 1-4 and commercially available waterborne fire retardant coatings.

[0135]

[0136] In summary, the beneficial effects of this invention are: the water-based fire-retardant coating provided by this invention has a simple preparation process, and the coating, after curing, possesses excellent fire resistance, high impact resistance, good toughness, and is not prone to cracking; it also maintains good stability under high temperature, high humidity, and high temperature environments; furthermore, the A / B components have a long activation time after mixing, are easy to apply, and have extremely low VOCs, effectively replacing high-performance outdoor solvent-based fire-retardant coatings; specifically:

[0137] (1) The water-based fireproof coating provided by the present invention has an activation time of up to 1 day after the A component and the B component are mixed. The viscosity changes very little during the activation period, and the construction is simple and convenient.

[0138] (2) The water-based fireproof coating provided by the present invention adopts the traditional “PNC” system. Through the optimization of the “PNC” system with titanium dioxide and expandable graphite, and by adding fireproof fiber, the strength of the char layer is further improved. The dry film coating with a thickness of only 2mm can expand more than 10 times under fire conditions to form a dense char layer with a certain strength and height, thereby playing a fireproof effect of flame retardancy and heat insulation, and the fire resistance limit of the char layer is more than 2 hours.

[0139] (3) The water-based fireproof coating provided by the present invention forms a unique three-dimensional structure through the chemical cross-linking effect between the elastic emulsion in component A and the cross-linking agent in component B, combined with fireproof fibers, which enables it to isotropically improve the mechanical function of the material. The combination of the three components further improves the mechanical strength and elastic modulus of the coating, resulting in good impact resistance and flexibility. The coating still has good mechanical stability under high and low temperature of -40~80℃ and humidity of 25%~99%.

[0140] (4) The water-based fireproof coating provided by the present invention forms a dense network structure to block water vapor through the chemical cross-linking effect between the elastic emulsion in component A and the cross-linking agent in component B, which effectively improves the water resistance, solvent resistance and damp heat resistance of the coating; and the active groups in component B can further improve the adhesion of the coating and avoid problems such as detachment from the substrate and blistering in the environment of alternating temperature and humidity.

[0141] (5) Combining the contents of part (2) above, Table 1 and the contents of the embodiments, it can be seen that the fire-retardant filler in the water-based fire-retardant coating provided by the present invention, ammonium polyphosphate, melamine, pentaerythritol, titanium dioxide and expandable graphite, combined with high silica fiber and other fibers, can enable the 2mm thick dry film coating to expand rapidly and effectively by 14 to 16 times under fire conditions, and the fire-retardant performance is significantly higher than that of commercially available water-based fire-retardant coatings provided by Henan Lianfang.

[0142] (6) Combining the contents of (3) and (4) above, Table 1 and the contents of the embodiments, it can be seen that the chemical cross-linking effect between the elastic emulsion in component A and the cross-linking agent in component B of the water-based fireproof coating provided by the present invention forms a dense network structure. Combined with high silica fiber and other fibers, it forms a unique three-dimensional structure that enables it to isotropically improve the mechanical function of the material. The combination of the three components makes the coating still have good mechanical stability after being subjected to high and low temperature of -40~80℃ and 25%~99% humidity for 500h. There is no bulging, cracking and peeling. The adhesion is not significantly reduced when pried by a blade. In contrast, the commercially available water-based fireproof coating provided by Henan Lianfang cracked and peeled after being subjected to high and low temperature of -40~80℃ and 25%~99% humidity for 500h. This shows that the temperature and humidity resistance of the water-based fireproof coating provided by the present invention is significantly higher than that of the commercially available water-based fireproof coating provided by Henan Lianfang.

[0143] (7) Combining the contents of (5) and (6) above, it can be seen that the water-based fireproof coating provided by the present invention has excellent resistance to temperature and humidity changes when not exposed to fire, and can exert excellent fireproof performance when exposed to fire.

[0144] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water-based coating resistant to alternating temperature and humidity, characterized in that, include: Component A and Component B; Component A includes: elastic emulsion, antifreeze, film-forming aid, wetting and dispersing agent, defoamer, thickener, multifunctional additive, water, and at least one of glass fiber, high silica fiber, and sepiolite fiber; Component B includes a crosslinking agent.

2. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The crosslinking agent is selected from at least one of isocyanate curing agents, oxazoline crosslinking agents, or aziridine crosslinking agents.

3. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, Component A contains 25 to 55 parts by weight of elastic emulsion, calculated in parts by weight. Antifreeze 1-4 parts by weight; 1-4 parts by weight of film-forming aid; Wetting and dispersing agent: 0.1-3 parts by weight; Defoamer 0.1~3 parts by weight; Thickener 0.1~3 parts by weight; Multifunctional additive, 0.1-2 parts by weight; 2-11 parts by weight of water; 2 to 6 parts by weight of at least one of glass fiber, high silica fiber, and sepiolite fiber; Component B includes: 1 to 10 parts by weight of crosslinking agent.

4. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The elastic emulsion is selected from at least one of styrene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, vinyl acetate-acrylic emulsion, and waterborne polyurea emulsion.

5. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The antifreeze is propylene glycol.

6. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The film-forming aid is selected from at least one of dodecyl alcohol ester, propylene glycol butyl ether, and dipropylene glycol methyl ether.

7. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The wetting and dispersing agent is selected from at least one of sodium carboxylate salts, polymeric alkyl alcohol ammonium salts, and acrylate copolymer ammonium salts.

8. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The thickener is selected from at least one of acrylic thickeners, polyurethane thickeners, and fumed silica.

9. The water-based coating resistant to alternating temperature and humidity according to claim 1, characterized in that, The multifunctional additive is At least one of them.

10. A method for preparing a waterborne coating resistant to temperature and humidity alternation, characterized in that, The preparation of a temperature and humidity resistant waterborne fire coating according to any one of claims 1-9 includes the following steps: a) Mix the elastic emulsion, antifreeze, film-forming aid and water evenly, then add wetting and dispersing agent, defoamer, multifunctional aid and at least one of glass fiber, high silica fiber and sepiolite fiber in sequence and stir to obtain slurry; b) Add a thickener to the above slurry and disperse to obtain component A; c) Stir the above component A and component B crosslinking agent evenly to obtain a water-based coating resistant to temperature and humidity alternation.

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