Windable fireproof coating as well as preparation method and application thereof

Abstract

The invention provides a reelable fireproof coating and a preparation method and application thereof, the reelable fireproof coating is composed of a component A and a component B. The component A comprises the following components: polyether diamine type asparagus resin, a defoaming agent, calcium carbonate, modified expanded graphite, ceramic fibers, a water absorbent, ammonium polyphosphate and a flame-retardant plasticizer; the component B comprises the following components: expanded graphite particles and isocyanate; the modified expanded graphite is a reaction product of polyfunctional epoxy resin, polyethyleneimine and oxidized expanded graphite. The polyether diamine type asparagus resin is used as matrix resin, the modified oxidized expanded graphite is added, crosslinking and synergistic effects among the components are good, the coating is endowed with better flexibility, so that the coating can be wound, meanwhile, the stability, aging resistance and flame retardance of a product are enhanced, the service life of the coating is longer, and the service life of the coating is prolonged. The protective effect can be stably achieved in an extreme environment, and the problems existing in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a rollable fire-retardant coating, its preparation method, and its application. Background Technology

[0002] Conventional fire-retardant coatings are primarily epoxy-based, while acrylic resin-based and epoxy-based fire-retardant coatings generally have poor flexibility and high rigidity. Furthermore, acrylic resins have poor water resistance and are highly hygroscopic. Currently, the corrosion and fire protection of bridge cable stays mostly relies on ordinary fire-retardant coatings with limited protective effects, or methods involving wrapping with fiber cloth. Ordinary fire-retardant coatings have limited fire resistance and are prone to photo-aging, leading to fire-retardant failure and frequent repairs with high maintenance costs. Wrapping fire-retardant felts such as aerogel felt and fiber cloth around the cable stays not only results in significant weight but also makes them highly susceptible to moisture absorption, a problem particularly pronounced in humid and hot southern regions and coastal areas. The increased weight of the fiber cloth after absorbing moisture significantly increases the overall load on the cable stays, severely impacting the bridge's service life and operational safety. In addition, some proposals have suggested using sleeves to protect the surface of the stay cables. However, this method has the problem that the sleeves are difficult to fix effectively to the stay cables. Furthermore, the sleeves have a larger diameter and surface area than the stay cables, which would increase the overall wind resistance of the cable-stayed bridge and fail to meet the wind resistance limit requirements for cable-stayed bridges.

[0003] Therefore, in view of the many practical problems existing in the corrosion and fire protection of cable-stayed bridge cables, developing a new type of anti-corrosion and fireproof coating that can achieve efficient corrosion and fire protection for cable-stayed cables, is lightweight and does not increase the wind resistance and self-weight of cable-stayed bridges, and is convenient to construct and easy to replace and maintain has become one of the technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0004] To address the deficiencies and shortcomings of the existing technology, this invention provides a rollable fire-retardant coating, its preparation method, and its application. This invention uses polyether diamine-type aspartic resin as the base resin and incorporates modified oxidized expanded graphite. The excellent cross-linking and synergistic effects among the various components not only endow the coating with better flexibility, enabling it to be rolled, but also enhance the product's stability, aging resistance, and flame retardancy, resulting in a longer service life and stable protective performance in extreme environments, thus solving the problems existing in the prior art.

[0005] One object of the present invention is to provide a rollable fire-retardant coating, wherein the rollable fire-retardant coating is composed of component A and component B. Component A comprises the following components in parts by mass: 25-70 parts of polyether diamine aspartic resin 0.2-2 parts of defoamer 0.5-5 parts calcium carbonate 3-20 parts modified expanded graphite 0.5-10 parts ceramic fiber 0.5-12 parts water absorbent 5-45 parts of ammonium polyphosphate 5-30 parts of flame retardant plasticizer; Component B comprises the following components in parts by mass: 2-15 parts of expanded graphite particles 85-98 parts of isocyanate; The modified expanded graphite is a product of the reaction of multifunctional epoxy resin, polyethyleneimine, and oxidized expanded graphite.

[0006] Furthermore, the functionality of the polyether diamine aspartic resin is 1.8-2.

[0007] Furthermore, the isocyanate is an isophorone diisocyanate trimer.

[0008] Furthermore, the polyethyleneimine is branched polyethyleneimine.

[0009] Furthermore, the multifunctional epoxy resin is ethylene glycol diglycidyl ether.

[0010] Furthermore, the flame retardant plasticizer is selected from one or more of tert-butylated aryl phosphate, triphenyl phosphate, and dibutylaluminum hypophosphite.

[0011] Furthermore, the phosphorus content of the flame retardant plasticizer is 8-13 wt%.

[0012] Furthermore, the tert-butylated aryl phosphate is composed of tert-butylphenyl diphenyl phosphate, bis(tert-butylphenyl)phenyl phosphate, and tri(tert-butylphenyl) phosphate. The combination of these three components exhibits excellent anti-yellowing properties, superior hydrolytic stability, low volatility, and low atomization. The resulting foam possesses good compressibility and offers advantages such as synergistic flame retardancy, enhanced char formation, and improved thermal stability.

[0013] Another object of the present invention is to provide a method for preparing the above-mentioned rollable fire-retardant coating, the method comprising the following steps: S1. Oxidized expanded graphite, multifunctional epoxy resin and accelerator are mixed and heated to react to obtain an intermediate product. S2. The intermediate product and polyethyleneimine are mixed and heated to react, resulting in modified expanded graphite. S3. Mix the modified expanded graphite with the remaining components in component A to obtain component A, and mix the components in component B to obtain component B.

[0014] Furthermore, the temperature of the heating reaction is 60-100℃.

[0015] Furthermore, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30).

[0016] Furthermore, it also includes: S4. Mix component A and component B, and apply a film with a thickness of 0.1-5 mm to the surface of the molding plate by spraying or scraping. S5. Curing for 12-60 hours yields a rollable fireproof coating.

[0017] Another object of the present invention is to provide the application of the above-mentioned rollable fireproof coating in the fireproof and corrosion protection construction of steel cables and steel structures.

[0018] Another object of the present invention is to provide a method for applying the above-mentioned rollable fire-retardant coating in the fireproofing and corrosion protection construction of steel cables, comprising the following steps: First, clean the surface of the steel cable. Then, spray or brush a layer of fire-retardant adhesive onto the surface of the steel cable. Before the fire-retardant adhesive layer cures, quickly bond and wrap the rollable fire-retardant coating onto the surface of the steel cable. Let it dry at room temperature and pressure for 3-8 hours.

[0019] Preferably, at least two layers are wrapped in a staggered manner during the winding process, and each layer is bonded and fixed with fire-retardant adhesive.

[0020] The rollable fire-retardant coating of this invention can complete the reaction at room temperature, has a short curing time, and produces a fire-retardant coating layer with excellent flexibility. Furthermore, when continuously sprayed with a high-temperature flame for 1 hour, the coating expands by more than 13 times under the influence of the flame, reaching a maximum of 14.5 times. Therefore, the fire-retardant coating of this invention is expected to replace the potential hazards to bridges caused by the moisture absorption and wind resistance changes resulting from the wrapping of fiber cloth around steel cables and stay cables, and also addresses the problem of poor performance of previous fire-retardant coatings. It is lightweight, easy to apply, and convenient to use.

[0021] In addition, this invention changes the conventional construction methods of fireproof and anti-corrosion coatings, which require on-site spraying, brushing, and roller coating. Instead, it can pre-mold and obtain a roll of fireproof coating that can be wound. When wrapping the coating on the substrate surface, only a small amount of fireproof adhesive needs to be sprayed to secure it firmly. There is no need to wait for curing time, which greatly shortens the overall construction period on site and eliminates the need for the support of a large construction site (in the past, when fireproof coatings were sprayed on site, it was necessary to wait half a day to a day for curing after spraying, and a curing site and a construction site were required for the substrate).

[0022] The present invention has the following beneficial effects: This invention provides a rollable fire-retardant coating using polyether diamine-type long-chain, low-functionality aspartic resin as the base resin. This component reacts rapidly with isocyanates and exhibits good aging resistance, ensuring the coating's weather resistance. Furthermore, this invention introduces epoxy groups by reacting oxidized expanded graphite with multifunctional epoxy resin, followed by further reaction with polyethyleneimine to obtain modified expanded graphite. This introduces a large number of active amino groups and branched structures, thereby avoiding the problem of uneven dispersion of expanded graphite particles. The active functional groups can crosslink with the base resin and other components through chemical bonds and intermolecular forces, which not only shortens the curing time but also forms a three-dimensional network structure, further ensuring the coating's adhesion, strength, and stability. In addition, this invention, through the compounding of various flame-retardant plasticizers with modified expanded graphite and expanded graphite particles, endows the product with excellent flame retardancy. Through the synergistic effect of multiple physical and chemical flame-retardant mechanisms, it achieves highly efficient isolation of flames and heat. It can be used not only for fire and corrosion protection in bridge-related fields but also for fire and corrosion protection of substrates in steel structures, docks, and ships, showing promising application prospects. Attached Figure Description

[0023] Figure 1 An appearance image of the rollable fire-retardant coating sample prepared in Example 1 is shown.

[0024] Figure 2 The image shows the adhesion effect of the rollable fireproof coating prepared in Example 1 on the surface of a steel pipe.

[0025] Figure 3 The bending effect diagram of the rollable fireproof coating prepared in Example 1 is shown.

[0026] Figure 4 The image shows the effect of the rollable fire-retardant coating prepared in Example 1.

[0027] Figure 5 The image shows the effect of the rollable fire-retardant coating prepared in Example 1 being wrapped around the outside of a pipe.

[0028] Figure 6 The image shows the appearance of the rollable fire-retardant coating prepared in Example 1 after a high-temperature flame test.

[0029] Figure 7 The diagram shows a cross-sectional view of the carbon layer of the rollable fire-retardant coating prepared in Example 1 after a high-temperature flame test. Detailed Implementation

[0030] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0031] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0032] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0033] The following raw materials are used in the embodiments and comparative examples of this invention: Polyether diamine type long-chain low-functionality aspartic resin: purchased from Shenzhen Feiyang Junyan Materials Co., Ltd., model F520.

[0034] Defoamer: BYK-1794.

[0035] Ceramic fiber: Isofrax 1260C.

[0036] Water absorbent: Incozol 2.

[0037] Ammonium polyphosphate: Molecular formula: (NH4PO3) n , n>1000, Product brand: CF-APP201.

[0038] Flame retardant plasticizers: tert-butylphenyl diphenyl phosphate, bis(tert-butylphenyl) phenyl phosphate, and tri(tert-butylphenyl) phosphate in a mass ratio of 2:1:1 were all purchased from Zhejiang Wansheng.

[0039] Expanded graphite particles: purchased from Qingdao Tianheda Co., Ltd., model 9580250, with a particle size ≤200 μm and an expansion volume ≥230 mL / g at 1200℃.

[0040] Isophorone diisocyanate trimer: Z4470.

[0041] The oxidized expanded graphite was prepared in-house, and the preparation method included the following steps: 1g of expandable graphite (EG, 50 mesh) and 0.5g of NaNO3 were added to a container. Under ice bath conditions, 70mL of concentrated sulfuric acid was poured in. After stirring magnetically at 4℃ for 10min, 3g of KMnO4 was added (0.5g every 5min, for a total of 30min). After the addition was complete, stirring was continued for 8h. Then, 50mL of deionized water was added, followed by 20mL of 5wt% hydrogen peroxide for oxidation. The reaction was stirred for 1h. The mixture was centrifuged and freeze-dried to obtain oxidized expanded graphite.

[0042] Branched polyethyleneimine: Aladdin P434400.

[0043] Example 1 A rollable fire-retardant coating, wherein the rollable fire-retardant coating is composed of component A and component B. Component A comprises the following components in parts by mass: 55 parts of polyether diamine type long-chain low-functionality aspartic resin 2 parts defoamer 5 parts calcium carbonate 16 parts of modified expanded graphite 9 parts ceramic fiber 8 parts water absorbent 40 parts of ammonium polyphosphate 28 parts flame retardant plasticizer; Component B comprises the following components in parts by mass: 12 parts of expanded graphite particles 85 parts of isophorone diisocyanate trimer; The method for preparing the rollable fire-retardant coating includes the following steps: S1. Mix oxidized expanded graphite, ethylene glycol diglycidyl ether and DMP-30 in a mass ratio of 1:20:0.21, react at 100℃ for 6 h, centrifuge, wash with acetone, and dry to obtain intermediate product. S2. Using ethanol as a solvent, the intermediate product and branched polyethyleneimine were mixed in a mass ratio of 1:1, stirred at 60°C for 4 h, and then centrifuged, washed and dried to obtain modified expanded graphite. S3. Mix the modified expanded graphite and the remaining components in component A according to the above-mentioned mass proportions to obtain component A; mix the components in component B to obtain component B. S4. Mix component A and component B, and apply the mixture to the surface of the molding plate by spraying to obtain a film layer with a thickness of 2 mm. S5. Curing at room temperature for 48 hours yields a rollable fireproof coating.

[0044] Example 2 A rollable fire-retardant coating, wherein the rollable fire-retardant coating is composed of component A and component B. Component A comprises the following components in parts by mass: 70 parts of polyether diamine type long-chain low-functionality aspartic resin 2 parts defoamer 5 parts calcium carbonate 20 parts modified expanded graphite 10 parts ceramic fiber 12 parts water absorbent 45 parts of ammonium polyphosphate 30 parts flame retardant plasticizer; Component B comprises the following components in parts by mass: 15 parts of expanded graphite particles 98 parts of isophorone diisocyanate trimer; The method for preparing the rollable fire-retardant coating includes the following steps: S1. Mix oxidized expanded graphite, ethylene glycol diglycidyl ether and DMP-30 in a mass ratio of 1:20:0.21, react at 100℃ for 6 h, centrifuge, wash with acetone, and dry to obtain intermediate product. S2. Using ethanol as a solvent, the intermediate product and branched polyethyleneimine were mixed in a mass ratio of 1:1, stirred at 60°C for 4 h, and then centrifuged, washed and dried to obtain modified expanded graphite. S3. Mix the modified expanded graphite and the remaining components in component A according to the above-mentioned mass proportions to obtain component A; mix the components in component B to obtain component B. S4. Mix component A and component B, and apply the mixture to the surface of the molding plate by spraying to obtain a film layer with a thickness of 2 mm. S5. Curing at room temperature for 48 hours yields a rollable fireproof coating.

[0045] Example 3 A rollable fire-retardant coating, wherein the rollable fire-retardant coating is composed of component A and component B. Component A comprises the following components in parts by mass: 60 parts of polyether diamine type long-chain low-functionality aspartic resin 1.8 parts defoamer 4 parts calcium carbonate 17 parts of modified expanded graphite 8 parts ceramic fiber 9 parts water absorbent 35 parts of ammonium polyphosphate 26 parts flame retardant plasticizer; Component B comprises the following components in parts by mass: 13 parts of expanded graphite particles 94 parts of isophorone diisocyanate trimer; The method for preparing the rollable fire-retardant coating includes the following steps: S1. Mix oxidized expanded graphite, ethylene glycol diglycidyl ether and DMP-30 in a mass ratio of 1:20:0.21, react at 100℃ for 6 h, centrifuge, wash with acetone, and dry to obtain intermediate product. S2. Using ethanol as a solvent, the intermediate product and branched polyethyleneimine were mixed in a mass ratio of 1:1, stirred at 60°C for 4 h, and then centrifuged, washed and dried to obtain modified expanded graphite. S3. Mix the modified expanded graphite and the remaining components in component A according to the above-mentioned mass proportions to obtain component A; mix the components in component B to obtain component B. S4. Mix component A and component B, and apply the mixture to the surface of the molding plate by spraying to obtain a film layer with a thickness of 2 mm. S5. Curing at room temperature for 48 hours yields a rollable fireproof coating.

[0046] Comparative Example 1 A rollable fireproof coating, the difference between this comparative example and Example 1 is that step S2 is deleted, and an intermediate product is used as modified expanded graphite; in step S5, the room temperature curing time is extended to 50 h, and other components and preparation methods are the same as in Example 1.

[0047] Comparative Example 2 A rollable fireproof coating, the difference between this comparative example and Example 1 is that: steps S1-S2 are modified to: oxidized expanded graphite and branched polyethyleneimine are mixed and stirred evenly in a mass ratio of 1:1 to obtain modified expanded graphite; in step S5, the room temperature curing time is extended to 55 h, and other components and preparation methods are the same as in Example 1.

[0048] Test case Performance tests were conducted on the rollable fire-retardant coatings prepared in the examples and comparative examples.

[0049] Test method: Tensile strength: Refer to GB / T 16777-2008.

[0050] Flexibility: Tested according to GB / T 1731-2020, shaft bending method.

[0051] Expansion: Tested according to the national standard GB 14907.

[0052] Weather resistance: Tested according to GB / T 16422.3 2022 method.

[0053] Water resistance: The test shall be conducted by the room temperature immersion method in GB / T 1733.

[0054] Fire resistance: Tested according to the method of GB / T 9978.1-2008.

[0055] The test results are shown in Table 1.

[0056] Table 1 Performance Test Results Figure 1 An appearance image of the rollable fire-retardant coating sample prepared in Example 1 is shown.

[0057] Figure 2 The image shows the adhesion effect of the rollable fireproof coating prepared in Example 1 on the surface of a steel pipe.

[0058] Figure 3 The bending effect diagram of the rollable fireproof coating prepared in Example 1 is shown.

[0059] Figure 4 The image shows the effect of the rollable fire-retardant coating prepared in Example 1.

[0060] Figure 5 The image shows the effect of the rollable fire-retardant coating prepared in Example 1 being wrapped around the outside of a pipe.

[0061] Figure 6 The image shows the appearance of the rollable fire-retardant coating prepared in Example 1 after a high-temperature flame test. It can be seen that no obvious cracking, movement, or peeling of the carbon layer was observed.

[0062] Figure 7 A cross-sectional view of the carbon layer of the rollable fire-retardant coating prepared in Example 1 after a high-temperature flame test is shown. It can be seen that the expanded carbon layer of the coating is relatively dense.

[0063] Based on the above test results, it can be concluded that the embodiments of the present invention effectively improve the comprehensive performance of the coating by modifying expanded graphite. This not only endows the product with a rollable function but also ensures the coating's water resistance and weather resistance, while also possessing high mechanical strength and excellent flame retardancy. In contrast, comparative examples 1-2, which replaced the modified expanded graphite, struggled to form an ideal cross-linked, network structure between the components, resulting in varying degrees of reduction in strength and weather resistance. Furthermore, due to the insufficient uniformity of the expanded graphite and its inadequate bonding with the resin, the fire-retardant performance also declined. In conclusion, the rollable fire-retardant coating of the present invention overcomes the shortcomings of the prior art and is of great significance to the development of fire-retardant coatings.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A rollable fire-retardant coating, characterized in that, The rollable fire-retardant coating consists of component A and component B. Component A comprises the following components in parts by mass: 25-70 parts of polyether diamine aspartic resin 0.2-2 parts of defoamer 0.5-5 parts calcium carbonate 3-20 parts modified expanded graphite 0.5-10 parts ceramic fiber 0.5-12 parts water absorbent 5-45 parts of ammonium polyphosphate 5-30 parts of flame retardant plasticizer; Component B comprises the following components in parts by mass: 2-15 parts of expanded graphite particles 85-98 parts of isocyanate; The modified expanded graphite is a product of the reaction of multifunctional epoxy resin, polyethyleneimine, and oxidized expanded graphite.

2. The rollable fire-retardant coating according to claim 1, characterized in that, The functionality of the polyether diamine-type aspartic resin is 1.8-2.

3. The rollable fire-retardant coating according to claim 1, characterized in that, The isocyanate is an isophorone diisocyanate trimer.

4. The rollable fire-retardant coating according to claim 1, characterized in that, The polyethyleneimine is a branched polyethyleneimine.

5. The rollable fire-retardant coating according to claim 1, characterized in that, The multifunctional epoxy resin is ethylene glycol diglycidyl ether.

6. The rollable fire-retardant coating according to claim 1, characterized in that, The flame retardant plasticizer is selected from one or more of tert-butylated aryl phosphate, triphenyl phosphate, and dibutyl aluminum hypophosphite.

7. The method for preparing the rollable fire-retardant coating according to any one of claims 1-6, characterized in that, The method for preparing the rollable fire-retardant coating includes the following steps: S1. Oxidized expanded graphite, multifunctional epoxy resin and accelerator are mixed and heated to react to obtain an intermediate product. S2. The intermediate product and polyethyleneimine are mixed and heated to react, resulting in modified expanded graphite. S3. Mix the modified expanded graphite with the remaining components in component A to obtain component A, and mix the components in component B to obtain component B.

8. The method for preparing the rollable fire-retardant coating according to claim 7, characterized in that, The temperature of the heating reaction is 60-100℃.

9. The method for preparing the rollable fire-retardant coating according to claim 7, characterized in that, Also includes: S4. Mix component A and component B and coat them onto the surface of the molding plate to obtain a film with a thickness of 0.1-5 mm. S5. Curing for 12-60 hours yields a rollable fireproof coating.

10. The application of the rollable fire-retardant coating according to any one of claims 1-6 in the fireproofing and corrosion protection construction of steel cables and steel structures.

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