Water-based intumescent fireproof coating as well as preparation method and application thereof

Abstract

The invention provides a water-based intumescent fireproof coating as well as a preparation method and application thereof, and relates to the technical field of coating materials. The water-based intumescent fireproof coating is prepared from the following components in parts by weight: 25 to 35 parts of water-based silicone acrylic emulsion, 40 to 60 parts of flame retardant, 15 to 25 parts of water, 5 to 10 parts of titanium dioxide and 1 to 5 parts of coalescing agent, wherein the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine. According to the water-based intumescent fireproof coating disclosed by the invention, the silicone acrylic emulsion is used as a main film forming substance, the 1-cyclohexylpiperazine modified ammonium polyphosphate is used as a flame retardant, and the titanium dioxide is used as a filler to form a fireproof intumescent system, so that the water-based intumescent fireproof coating has the advantages of simple production process, excellent performance, environment friendliness and the like; and the prepared fireproof coating has good fireproof performance and durability.

Description

Technical Field

[0001] The invention relates to the technical field of coating materials, and in particular to a water-based intumescent fire-retardant coating and a preparation method and application thereof. Background Art

[0002] Fire retardant coating is a special coating that can act on the surface of the substrate to increase its fire resistance time. At the same time, it plays a certain protective and decorative role on the substrate, can prevent fire and delay the spread of fire, minimize the loss of life and property caused by fire, and play a significant role in improving the fire safety level of related places. Fire retardant coatings are generally divided into non-expanding fire retardant coatings and expanding fire retardant coatings based on the fire retardant mechanism.

[0003] Generally speaking, chemical reaction type intumescent steel structure fire retardant coatings mainly use "acid source", "gas source" and "carbon source" materials to form a fire retardant system. During the combustion process, the "carbon source" participates in the carbonization process under the catalytic action of the "acid source", and the formed carbon expands under the action of the "gas source" to form an intumescent carbon layer. The formed carbon layer can reduce the heat transfer between the heat source and the substrate surface, and isolate oxygen transfer. The carbon layer has good thermal insulation and low thermal conductivity, which can improve the fire retardant performance of the coating to a certain extent, thereby protecting the substrate and slowing down the temperature rise of the substrate.

[0004] Usually, the fireproof system of such water-based intumescent fireproof coatings uses different materials as "acid source", "gas source" and "carbon source", with ammonium polyphosphate, melamine and pentaerythritol being the most common, and they are dispersed in the coating system together with water, additives, film-forming substances and other pigments and fillers. This dispersion method poses certain challenges to the dispersion of fireproof systems and pigments and fillers, and there is currently a lack of research on the synergistic mechanism and matching between different flame retardants.

[0005] In addition, developing a new type of "three-source-in-one" intumescent flame retardant is a future research direction, which combines the advantages of "acid source", "gas source" and "carbon source" to improve the expansion efficiency of the fireproof system and the fireproof performance of the coating. At present, some studies have modified ammonium polyphosphate by adding ethylenediamine, ethanolamine, piperazine and other substances to the molecular chain of ammonium polyphosphate. With ammonium polyphosphate as the main "acid source and gas source" and other groups as "carbon source", it can play a fireproof and flame-retardant role on materials such as PE and PP. The application of this type of flame retardant in fire-retardant coatings has not yet been proposed.

[0006] CN101205441A discloses a steel structure fireproof coating based on a self-crosslinking silicone-acrylic composite emulsion and a preparation method thereof. The fireproof coating is composed of a polyorganosiloxane emulsion, a self-crosslinking polyacrylate emulsion and a fireproofing auxiliary agent, and is supplemented with a filler, a film-forming auxiliary agent and an early foaming agent, wherein the fireproofing auxiliary agent is ammonium polyphosphate, melamine phosphate, melamine and pentaerythritol, and the filler is titanium dioxide, sepiolite and aluminum silicate fiber. However, the fireproofing auxiliary agent is obtained by simply stirring and blending ammonium polyphosphate, melamine phosphate, melamine and pentaerythritol, and these components not only have poor dispersibility in the aqueous emulsion, but also the expansion ratio of the carbon layer of the fireproof coating formed in the end is low when it encounters fire.

[0007] CN116554482A discloses a highly heat-resistant and precipitation-resistant chemically blocked focused piperazine phosphate modified ammonium polyphosphate and a preparation method thereof. The preparation method is based on ammonium polyphosphate, which is modified with focused piperazine phosphate and then blocked; and the focused piperazine phosphate is obtained by dehydration condensation of phosphoric acid and piperazine to obtain an intermediate diphosphate piperazine, which is then polymerized. This modification method is difficult to introduce more "carbon sources", so if it is directly added as a flame retardant to a water-based intumescent fire-retardant coating, the coating formed after curing has poor charring and thermal stability when it expands in the event of fire.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] The purpose of the present invention is to provide a water-based intumescent fire-retardant coating and its preparation method and application. The water-based intumescent fire-retardant coating uses silicone-acrylic emulsion as the main film-forming substance, 1-cyclohexylpiperazine-modified ammonium polyphosphate as a flame retardant, and titanium dioxide as a filler to form a fire-retardant expansion system, so that the carbon layer of the fire-retardant coating has a higher expansion ratio when it encounters fire, and significantly enhances the carbonization and thermal stability of the coating when it expands when it encounters fire.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0011] In a first aspect, the present invention provides a water-based intumescent fire retardant coating, wherein the water-based intumescent fire retardant coating comprises the following components in parts by weight:

[0012]

[0013] Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

[0014] Preferably, the raw materials for preparing the 1-cyclohexylpiperazine-modified ammonium polyphosphate include ammonium polyphosphate and 1-cyclohexylpiperazine in a molar ratio of 1:(1-2).

[0015] Preferably, the degree of polymerization of the ammonium polyphosphate is greater than 1000.

[0016] Preferably, the 1-cyclohexylpiperazine modified ammonium polyphosphate is prepared by the following steps:

[0017] In the presence of protective gas, ammonium polyphosphate and 1-cyclohexylpiperazine react in a mixed solvent of ethanol and water to obtain the 1-cyclohexylpiperazine-modified ammonium polyphosphate.

[0018] Preferably, the protective gas includes any one of nitrogen, argon or helium, or a combination of at least two of them.

[0019] Preferably, the volume ratio of ethanol to water is 100:(1-10).

[0020] Preferably, the ratio of the mass of the mixed solvent of ethanol and water to the total mass of the ammonium polyphosphate and 1-cyclohexylpiperazine is 1:(1-4).

[0021] Preferably, the reaction temperature is 85-95° C., and the reaction time is 3-6 h.

[0022] Preferably, after the reaction is completed, a post-treatment step is further included: the mixture obtained by the reaction is cooled, washed, and dried in sequence to obtain the 1-cyclohexylpiperazine-modified ammonium polyphosphate.

[0023] Preferably, the detergent used in the washing is ethanol.

[0024] Preferably, the water-based intumescent fire retardant coating further comprises 0.1 to 0.5 parts of an anti-settling agent.

[0025] Preferably, the anti-settling agent is organic bentonite.

[0026] Preferably, the water-based intumescent fire retardant coating further comprises 0.1 to 0.5 parts of a dispersant.

[0027] Preferably, the dispersant is a polycarboxylate dispersant.

[0028] Preferably, the water-based intumescent fire retardant coating further comprises 0.1 to 0.5 parts of a defoaming agent.

[0029] Preferably, the defoamer is a silicone defoamer.

[0030] Preferably, the water-based intumescent fire retardant coating further comprises 0.1 to 0.5 parts of an anti-flash rust agent.

[0031] Preferably, the flash rust inhibitor is a 30 wt % sodium nitrite aqueous solution.

[0032] In a second aspect, the present invention provides a method for preparing the waterborne intumescent fire retardant coating as described in the first aspect, the method for preparing the waterborne intumescent fire retardant coating comprising the following steps:

[0033] The water-based silicone acrylic emulsion, flame retardant, water, titanium dioxide and film-forming aid are mixed to obtain the water-based intumescent fire-retardant coating.

[0034] Preferably, the preparation method of the water-based intumescent fire retardant coating specifically comprises the following steps:

[0035] Mix water, a dispersant and a defoamer, and stir once to obtain a mixture 1;

[0036] The mixture 1, the flame retardant, the titanium dioxide and the anti-settling agent are mixed and stirred for a second time to obtain a mixture 2;

[0037] The mixture 2, the water-based silicone acrylic emulsion, the film-forming aid and the anti-flash rust agent are mixed and stirred three times to obtain the water-based intumescent fire retardant coating.

[0038] Preferably, the rotation speed of the primary stirring is 700-900 r / min, and the time of the primary stirring is 10-30 min.

[0039] Preferably, the rotation speed of the secondary stirring is 1400-1600 r / min, and the time of the secondary stirring is 20-40 min.

[0040] Preferably, the rotation speed of the three stirrings is 500-700 r / min, and the time of the three stirrings is 10-20 min.

[0041] In a third aspect, the present invention provides a use of the water-based intumescent fire retardant coating as described in the first aspect as a fire retardant coating for protecting carbon steel materials.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The fire-retardant coating of the present invention uses silicone-acrylic emulsion as the main film-forming substance, 1-cyclohexylpiperazine-modified ammonium polyphosphate as a flame retardant, and rutile titanium dioxide as a filler to form a fire-retardant expansion system. It has the advantages of simple production process, excellent performance, and green environmental protection. The prepared fire-retardant coating has good fire resistance and durability.

[0044] (2) The fire-retardant coating of the present invention uses 1-cyclohexylpiperazine-modified ammonium polyphosphate as the expansion flame retardant system of the fire-retardant coating. The 1-cyclohexylpiperazine-modified ammonium polyphosphate is uniformly dispersed in an aqueous emulsion by a dispersant. Compared with the traditional fire-retardant expansion system formed by ammonium polyphosphate, pentaerythritol and melamine, it has better dispersibility, so that the char layer of the fire-retardant coating has a higher expansion ratio when encountering fire.

[0045] (3) The fire-retardant coating of the present invention uses 1-cyclohexylpiperazine-modified ammonium polyphosphate as the expansion flame retardant system of the fire-retardant coating. Different from other piperazine-modified ammonium polyphosphate flame retardants, 1-cyclohexylpiperazine-modified ammonium polyphosphate can introduce more "carbon sources" into ammonium polyphosphate, thereby enhancing the carbonization and thermal stability of the coating when it expands in fire. DETAILED DESCRIPTION

[0046] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0047] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0048] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In a first aspect, the present invention provides a water-based intumescent fire retardant coating, wherein the water-based intumescent fire retardant coating comprises the following components in parts by weight:

[0050]

[0051] Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

[0052] In the present invention, silicone-acrylic emulsion is used as the main film-forming substance, 1-cyclohexylpiperazine-modified ammonium polyphosphate is used as a flame retardant, and rutile titanium dioxide is used as a filler to form a fire-retardant expansion system, which has the advantages of simple production process, excellent performance, and green environmental protection. The prepared fire-retardant coating has good fire resistance and durability.

[0053] In the present invention, 1-cyclohexylpiperazine modified ammonium polyphosphate is used as the expansion flame retardant system of the fire retardant coating. The 1-cyclohexylpiperazine modified ammonium polyphosphate can be evenly dispersed in the aqueous emulsion through a dispersant. Compared with the traditional fire retardant expansion system formed by ammonium polyphosphate, pentaerythritol and melamine, it has better dispersibility, so that the carbon layer of the fire retardant coating has a higher expansion ratio when it encounters fire. And unlike other ammonium polyphosphates modified by piperazine substances, 1-cyclohexylpiperazine modified ammonium polyphosphate can introduce more "carbon sources" into the ammonium polyphosphate, thereby enhancing the carbonization and thermal stability of the coating when it expands in the fire.

[0054] As an optional embodiment, the content of the aqueous silicone acrylic emulsion is 25 to 35 parts, for example, it can be 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, etc.

[0055] As an optional embodiment, the content of the flame retardant is 40 to 60 parts, for example, it can be 40 parts, 42 parts, 44 parts, 45 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 55 parts, 56 parts, 58 parts, 60 parts, etc.

[0056] As an optional embodiment, the water content is 15 to 25 parts, for example, it can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, etc.

[0057] As an optional embodiment, the content of titanium dioxide is 5 to 10 parts, for example, it can be 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, etc.

[0058] As an optional embodiment, the content of the film-forming aid is 1 to 5 parts, for example, it can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0059] As an optional embodiment, the structural formula of the 1-cyclohexylpiperazine modified ammonium polyphosphate is shown in the following formula I:

[0060]

[0061] As an optional embodiment, the raw materials for preparing the 1-cyclohexylpiperazine-modified ammonium polyphosphate include ammonium polyphosphate and 1-cyclohexylpiperazine.

[0062] In the present invention, the flame retardant 1-cyclohexylpiperazine modified ammonium polyphosphate is prepared by using 1-cyclohexylpiperazine modified ammonium polyphosphate, which integrates the acid source, carbon source and gas source. In the initial stage of the coating encountering fire, with the release of NH3 and H2O, a PNC structure is formed during the combustion process, thereby forming a relatively stable carbon layer. Then, as the temperature rises, part of the PNC structure decomposes under the catalytic action of P-OH, while releasing H2O and NH3. Most of the PNC structure and other stable structures (such as C=C, etc.) are combined with the gas source to promote and form an expanded, dense and stable carbon layer, thereby achieving the excellent fireproof performance of the flame retardant 1-cyclohexylpiperazine modified ammonium polyphosphate.

[0063] As an optional embodiment, the molar ratio of the ammonium polyphosphate to 1-cyclohexylpiperazine is 1:(1-2), for example, it can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, etc.

[0064] As an optional embodiment, the degree of polymerization of the ammonium polyphosphate is greater than 1000, for example, it can be 1100, 1200, 1400, 1500, 1600, 1800, 2000, 3000, 4000, 5000, etc.

[0065] As an optional embodiment, the 1-cyclohexylpiperazine modified ammonium polyphosphate is prepared by the following steps:

[0066] In the presence of protective gas, ammonium polyphosphate and 1-cyclohexylpiperazine react in a mixed solvent of ethanol and water to obtain the 1-cyclohexylpiperazine-modified ammonium polyphosphate.

[0067] As an optional embodiment, the protective gas includes any one of nitrogen, argon or helium, or a combination of at least two of them.

[0068] As an optional embodiment, the volume ratio of ethanol to water is 100:(1-10), for example, it can be 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, etc.

[0069] As an optional embodiment, the ratio of the mass of the mixed solvent of ethanol and water to the total mass of the ammonium polyphosphate and 1-cyclohexylpiperazine is 1:(1-4)), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, etc.

[0070] As an optional embodiment, the reaction temperature is 85-95°C, for example, it can be 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, etc.

[0071] As an optional embodiment, the reaction time is 3 to 6 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, etc.

[0072] As an optional embodiment, after the reaction is completed, a post-treatment step is further included: the mixture obtained by the reaction is cooled, washed, and dried in sequence to obtain the 1-cyclohexylpiperazine modified ammonium polyphosphate.

[0073] As an optional embodiment, the detergent used for washing is ethanol.

[0074] As an optional embodiment, the water-based intumescent fire retardant coating further includes 0.1 to 0.5 parts of an anti-settling agent, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0075] As an optional implementation, the anti-settling agent is organic bentonite.

[0076] As an optional embodiment, the water-based intumescent fire retardant coating further includes 0.1 to 0.5 parts of a dispersant, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0077] As an optional embodiment, the dispersant is a polycarboxylate dispersant.

[0078] As an optional embodiment, the dispersant is BYK-190.

[0079] As an optional embodiment, the water-based intumescent fire retardant coating further includes 0.1 to 0.5 parts of a defoaming agent, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0080] As an optional embodiment, the defoaming agent is a silicone defoaming agent.

[0081] As an optional implementation, the defoaming agent is BYK-024.

[0082] As an optional embodiment, the water-based intumescent fire retardant coating further includes 0.1 to 0.5 parts of an anti-flash rust agent, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0083] As an optional embodiment, the flash rust inhibitor is a 30 wt % sodium nitrite aqueous solution.

[0084] In a second aspect, the present invention provides a method for preparing the waterborne intumescent fire retardant coating as described in the first aspect, the method for preparing the waterborne intumescent fire retardant coating comprising the following steps:

[0085] The water-based silicone acrylic emulsion, flame retardant, water, titanium dioxide and film-forming aid are mixed to obtain the water-based intumescent fire-retardant coating.

[0086] Preferably, the preparation method of the water-based intumescent fire retardant coating specifically comprises the following steps:

[0087] Mix water, a dispersant and a defoamer, and stir once to obtain a mixture 1;

[0088] The mixture 1, the flame retardant, the titanium dioxide and the anti-settling agent are mixed and stirred for a second time to obtain a mixture 2;

[0089] The mixture 2, the water-based silicone acrylic emulsion, the film-forming aid and the anti-flash rust agent are mixed and stirred three times to obtain the water-based intumescent fire retardant coating.

[0090] In the present invention, this scheme adopts the above-mentioned preparation method, 1-cyclohexylpiperazine modified ammonium polyphosphate is used as the expansion flame retardant system of the fire retardant coating, and the 1-cyclohexylpiperazine modified ammonium polyphosphate is uniformly dispersed in the aqueous emulsion through a dispersant. Compared with the traditional fire retardant expansion system formed by ammonium polyphosphate, pentaerythritol and melamine, it has better dispersibility and has the advantage of a simple preparation process.

[0091] As an optional embodiment, the rotation speed of the stirring is 700-900r / min, for example, it can be 700r / min, 720r / min, 740r / min, 750r / min, 760r / min, 780r / min, 800r / min, 820r / min, 840r / min, 850r / min, 860r / min, 880r / min, 900r / min, etc., and the time of the stirring is 10-30min, for example, it can be 10min, 12min, 14min, 15min, 16min, 18min, 20min, 22min, 24min, 25min, 26min, 28min, 30min, etc.

[0092] As an optional embodiment, the rotation speed of the secondary stirring is 1400-1600r / min, for example, it can be 1400r / min, 1420r / min, 1440r / min, 1450r / min, 1460r / min, 1480r / min, 1500r / min, 1520r / min, 1540r / min, 1550r / min, 1560r / min, 1580r / min, 1600r / min, etc., and the time of the secondary stirring is 20-40min, for example, it can be 20min, 22min, 24min, 25min, 26min, 28min, 30min, 32min, 34min, 35min, 36min, 38min, 40min, etc.

[0093] As an optional embodiment, the rotation speed of the three stirrings is 500-700r / min, for example, it can be 500r / min, 520r / min, 540r / min, 550r / min, 560r / min, 580r / min, 600r / min, 620r / min, 640r / min, 650r / min, 660r / min, 680r / min, 700r / min, etc., and the time of the three stirrings is 10-20min, for example, it can be 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min, etc.

[0094] In a third aspect, the present invention provides a use of the water-based intumescent fire retardant coating as described in the first aspect as a fire retardant coating for protecting carbon steel materials.

[0095] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0096] The sources of the following components are as follows:

[0097]

[0098]

[0099] Example 1

[0100] This embodiment provides a water-based intumescent fire retardant coating, which comprises the following components in parts by weight:

[0101]

[0102] Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

[0103] The water-based intumescent fire retardant coating is prepared by the following steps:

[0104] (1) Preparation of flame retardant:

[0105] At room temperature, ethanol and water are mixed in a volume ratio of 100:5 to obtain a mixed solvent of ethanol and water, which is added to a reaction container, and nitrogen is introduced. Under a nitrogen atmosphere, ammonium polyphosphate and 1-cyclohexylpiperazine are added to the mixed solvent reaction container in a molar ratio of 1:1.5 (the ratio of the mass of the mixed solvent of ethanol and water to the total mass of the ammonium polyphosphate and 1-cyclohexylpiperazine is 2:1), stirred and heated to 90°C, and reacted for 4.5 hours; after the reaction is completed, the mixture is cooled to room temperature, washed with ethanol, and dried to obtain the 1-cyclohexylpiperazine-modified ammonium polyphosphate.

[0106] (2) Preparation of water-based intumescent fire retardant coating:

[0107] First, water, BYK-190 and BYK-024 are mixed according to the above weight proportions, and stirred at a speed of 800 r / min for 20 minutes; then the above weight proportions of rutile titanium dioxide, flame retardant and organic bentonite are added, and stirring is continued at a speed of 1500 r / min for 30 minutes; then the above weight proportions of water-based silicone acrylic emulsion, dipropylene glycol butyl ether and 30wt% sodium nitrite aqueous solution are added, and stirring is carried out at 600 r / min for 15 minutes to obtain a water-based intumescent fire retardant coating.

[0108] Example 2

[0109] This embodiment provides a water-based intumescent fire retardant coating, which comprises the following components in parts by weight:

[0110]

[0111] Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

[0112] The water-based intumescent fire retardant coating is prepared by the following steps:

[0113] (1) Preparation of flame retardant: the same as in Example 1.

[0114] (2) Preparation of water-based intumescent fire retardant coating: the same as in Example 1.

[0115] Example 3

[0116] This embodiment provides a water-based intumescent fire retardant coating, which comprises the following components in parts by weight:

[0117]

[0118] Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

[0119] The water-based intumescent fire retardant coating is prepared by the following steps:

[0120] (1) Preparation of flame retardant: the same as in Example 1.

[0121] (2) Preparation of water-based intumescent fire retardant coating: the same as in Example 1.

[0122] Example 4

[0123] This embodiment provides a water-based intumescent fire retardant coating, which comprises the following components in parts by weight:

[0124]

[0125]

[0126] The water-based intumescent fire retardant coating is prepared by the following steps:

[0127] (1) Preparation of flame retardant: the same as in Example 1.

[0128] (2) Preparation of water-based intumescent fire retardant coating: the same as in Example 1.

[0129] Example 5

[0130] This embodiment provides a water-based intumescent fire retardant coating, which comprises the following components in parts by weight:

[0131]

[0132] The water-based intumescent fire retardant coating is prepared by the following steps:

[0133] (1) Preparation of flame retardant: the same as in Example 1.

[0134] (2) Preparation of water-based intumescent fire retardant coating: the same as in Example 1.

[0135] Example 6

[0136] This embodiment provides a water-based intumescent fire retardant coating, which differs from Embodiment 1 only in that, in the process of preparing the flame retardant in step (1), the molar ratio of the ammonium polyphosphate and 1-cyclohexylpiperazine is 1:1, and the other steps are exactly the same as Embodiment 1.

[0137] Example 7

[0138] This embodiment provides a water-based intumescent fire retardant coating, which differs from Embodiment 1 only in that, in the process of preparing the flame retardant in step (1), the molar ratio of the ammonium polyphosphate and 1-cyclohexylpiperazine is 1:2, and the other steps are exactly the same as Embodiment 1.

[0139] Example 8

[0140] This embodiment provides a water-based intumescent fire retardant coating, which differs from Embodiment 1 only in that, during the process of preparing the flame retardant in step (1), the reaction temperature is 85° C., the reaction time is 6 hours, and the other steps are exactly the same as Embodiment 1.

[0141] Example 9

[0142] This embodiment provides a water-based intumescent fire retardant coating, which differs from Embodiment 1 only in that, during the process of preparing the flame retardant in step (1), the reaction temperature is 95° C. and the reaction time is 3 hours. The other steps are exactly the same as those in Embodiment 1.

[0143] Comparative Example 1

[0144] This comparative example provides a water-based coating, which differs from Example 1 only in that 45 parts of 1-cyclohexylpiperazine-modified ammonium polyphosphate are replaced with 45 parts of unmodified ammonium polyphosphate, and the other steps are exactly the same as Example 1.

[0145] Comparative Example 2

[0146] This comparative example provides a water-based coating, which differs from Example 1 only in that 45 parts of 1-cyclohexylpiperazine-modified ammonium polyphosphate are replaced with 45 parts of piperazine-modified ammonium polyphosphate (CN201310727560.2), and the other steps are exactly the same as those of Example 1;

[0147] Among them, the structural formula of piperazine modified ammonium polyphosphate is

[0148] Comparative Example 3

[0149] This comparative example provides a water-based coating, which differs from Example 1 only in that 45 parts of 1-cyclohexylpiperazine-modified ammonium polyphosphate are replaced with 45 parts of 1,4-cyclohexanediamine-modified ammonium polyphosphate (CN202010837257.8), and the other steps are exactly the same as those in Example 1;

[0150] Among them, the structural formula of 1,4-cyclohexanediamine modified ammonium polyphosphate is

[0151] Comparative Example 4

[0152] This comparative example provides a water-based coating, which differs from Example 1 only in that the content of the water-based silicone acrylic emulsion is 20 parts, the content of the flame retardant (1-cyclohexylpiperazine modified ammonium polyphosphate) is 50 parts, the content of rutile titanium dioxide is 12 parts, and the contents of other components and the preparation steps are consistent with those of Example 1.

[0153] Comparative Example 5

[0154] This comparative example provides a water-based coating, which differs from Example 1 only in that the content of the water-based silicone acrylic emulsion is 50 parts, the content of the flame retardant (ammonium polyphosphate modified by 1-cyclohexylpiperazine) is 30 parts, the content of rutile titanium dioxide is 2 parts, and the contents of other components and the preparation steps are consistent with those of Example 1.

[0155] Comparative Example 6

[0156] This comparative example provides a water-based coating, which differs from Example 1 only in that the content of the water-based silicone acrylic emulsion is 35 parts, the content of the flame retardant (ammonium polyphosphate modified by 1-cyclohexylpiperazine) is 30 parts, the content of rutile titanium dioxide is 17 parts, and the contents of other components and the preparation steps are consistent with those of Example 1.

[0157] Test Case

[0158] Test samples: the water-based intumescent fire retardant coatings provided in Examples 1 to 9, and the water-based intumescent fire retardant coatings provided in Comparative Examples 1 to 6.

[0159] Test method: Apply each sample evenly (coating amount is 3kg / m 2 ) On the corresponding substrate (carbon steel plate), the carbon steel plate was polished and degreased before applying the fire retardant coating. The performance parameters of each sample were tested in accordance with the relevant standards for fire retardant coatings (GB14907-2018).

[0160] The specific test results are shown in Table 1 below:

[0161] Table 1

[0162]

[0163]

[0164] As shown in Table 1, the back temperature of the steel plate of the water-based intumescent fire-retardant coating of the present invention is below 281°C, the expansion ratio reaches more than 15 times, and the carbon layer is firm and has good compactness. The water-based intumescent fire-retardant coating prepared by the present invention has good fireproof performance, and at high temperature, the expansion of the coating mainly depends on the film-forming material to wrap the inert gas released by the thermal decomposition of the flame retardant to form a honeycomb-shaped cellular carbon layer. It can be seen from Examples 1 to 5 that the coating provided by the present invention has good fireproof performance, indicating that the modified ammonium polyphosphate flame retardant has a "three-source-in-one" high-efficiency fireproof performance, can effectively improve the compactness and continuity of the carbon layer, and block the transfer of heat. The prepared water-based intumescent fire-retardant coating exhibits excellent fireproof performance. By comparing Example 1 with Comparative Example 1, it can be seen that the unmodified ammonium polyphosphate fails to form an expanded carbon layer of a certain thickness due to the lack of carbon source in the coating.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-based intumescent fire retardant coating, characterized in that: The water-based intumescent fire retardant coating comprises the following components by weight: Wherein, the flame retardant is ammonium polyphosphate modified by 1-cyclohexylpiperazine.

2. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The raw materials for preparing the 1-cyclohexylpiperazine-modified ammonium polyphosphate include ammonium polyphosphate and 1-cyclohexylpiperazine in a molar ratio of 1:(1-2); Preferably, the degree of polymerization of the ammonium polyphosphate is greater than 1000; Preferably, the 1-cyclohexylpiperazine modified ammonium polyphosphate is prepared by the following steps: In the presence of a protective gas, ammonium polyphosphate and 1-cyclohexylpiperazine react in a mixed solvent of ethanol and water to obtain the 1-cyclohexylpiperazine-modified ammonium polyphosphate; Preferably, the protective gas comprises any one of nitrogen, argon or helium, or a combination of at least two thereof; Preferably, the volume ratio of ethanol to water is 100:(1-10); Preferably, the ratio of the mass of the mixed solvent of ethanol and water to the total mass of the ammonium polyphosphate and 1-cyclohexylpiperazine is 1:(1-4); Preferably, the reaction temperature is 85-95°C, and the reaction time is 3-6h; Preferably, after the reaction is completed, a post-treatment step is further included: cooling, washing and drying the reaction mixture in sequence to obtain the 1-cyclohexylpiperazine modified ammonium polyphosphate; Preferably, the detergent used in the washing is ethanol.

3. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The titanium dioxide is rutile titanium dioxide; Preferably, the film-forming aid is dipropylene glycol butyl ether.

4. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The water-based intumescent fire retardant coating also includes 0.1 to 0.5 parts of an anti-settling agent; Preferably, the anti-settling agent is organic bentonite.

5. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The water-based intumescent fire retardant coating also includes 0.1 to 0.5 parts of a dispersant; Preferably, the dispersant is a polycarboxylate dispersant.

6. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The water-based intumescent fire retardant coating also includes 0.1 to 0.5 parts of a defoamer; Preferably, the defoamer is a silicone defoamer.

7. The water-based intumescent fire retardant coating according to claim 1, characterized in that: The water-based intumescent fire retardant coating also includes 0.1 to 0.5 parts of anti-flash rust agent; Preferably, the flash rust inhibitor is a 30 wt % sodium nitrite aqueous solution.

8. A method for preparing a waterborne intumescent fire retardant coating according to any one of claims 1 to 7, characterized in that: The preparation method of the water-based intumescent fire retardant coating comprises the following steps: The water-based silicone acrylic emulsion, flame retardant, water, titanium dioxide and film-forming aid are mixed to obtain the water-based intumescent fire-retardant coating.

9. The method for preparing the water-based intumescent fire retardant coating according to claim 8, characterized in that: The preparation method of the water-based intumescent fire retardant coating specifically comprises the following steps: Mix water, a dispersant and a defoamer, and stir once to obtain a mixture 1; The mixture 1, the flame retardant, the titanium dioxide and the anti-settling agent are mixed and stirred for a second time to obtain a mixture 2; The mixture 2, the water-based silicone acrylic emulsion, the film-forming aid and the anti-flash rust agent are mixed, and stirred three times to obtain the water-based intumescent fire retardant coating; Preferably, the rotation speed of the primary stirring is 700-900 r / min, and the time of the primary stirring is 10-30 min; Preferably, the rotation speed of the secondary stirring is 1400-1600 r / min, and the time of the secondary stirring is 20-40 min; Preferably, the rotation speed of the three stirrings is 500-700 r / min, and the time of the three stirrings is 10-20 min.

10. Use of the waterborne intumescent fire retardant coating according to any one of claims 1 to 7 as a fire retardant coating for protecting carbon steel materials.

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