Anti-explosion coating and preparation method thereof

Abstract

The invention discloses an anti-explosion coating and a preparation method thereof. The anti-explosion coating is composed of a component A and a component B in a volume ratio of 1: 1; the component A is composed of 91 wt% of a semi-prepolymer and 9 wt% of a diluent, and the semi-prepolymer is prepared from isocyanate MDI-50 and polytetrahydrofuran glycol; the component B is composed of 50-60 wt% of amine-terminated polyether, 38-48 wt% of an amine chain extender, 0-1 wt% of a filler carbon nanotube and 1 wt% of a defoaming agent, and the amine chain extender is composed of E300 and Unlink 4200 in a molar ratio of 1: 1-3: 1. The density of hydrogen bonds is improved through different amine chain extenders, the carbon nanotubes and a polymer matrix form a hydrogen bond cross-linked network, interaction in a polyurea structure is increased, and the anti-explosion coating has high protection capacity under the action of explosion impact loads.

Description

Technical Field

[0001] This invention belongs to the field of coating compositions and relates to an anti-explosion coating and its preparation method. Background Technology

[0002] In the engineering field, buildings and infrastructure frequently face various unexpected impacts, such as vehicles colliding with building facades or ships hitting docks. Therefore, to ensure the stability and safety of building or infrastructure structures, engineers often select or develop new materials with excellent energy absorption capabilities, such as polyurea, to spray onto the surface of buildings or infrastructure to enhance their impact resistance. Using these materials as coatings can effectively disperse and absorb energy upon impact, reducing damage to the building or infrastructure structure. Because the material response time is extremely short under high-speed impacts, especially explosive impacts, the requirements for the material's mechanical properties are very high. Coating materials in related technologies often struggle to simultaneously achieve both mechanical properties and blast resistance.

[0003] Chinese Patent 202010451640.X discloses a polyurea carbon fiber composite material with excellent tensile and tear strength. Chinese Patent 201910846432.7 discloses a two-component polyurea coating material with high hardness and impact resistance, but its explosion-proof performance needs improvement. Chinese Patent 202011094108.3 discloses an explosion-proof and impact-resistant polyurea coating with excellent explosion-proof and impact-resistant properties, but poor tear strength. Furthermore, the preparation of the above-mentioned explosion-proof coating materials requires specialized spraying equipment, making them difficult to use.

[0004] Therefore, there is an urgent need to develop coating materials that have strong protective capabilities under explosive impact loads and are easy to prepare. Summary of the Invention

[0005] The purpose of this invention is to provide an explosion-proof coating and its preparation method. This coating material has strong protective capabilities under the action of explosive impact loads and is simple to use.

[0006] The technical solution for achieving the objective of this invention is as follows:

[0007] An explosion-proof coating comprises component A and component B in a volume ratio of 1:1. Component A consists of 91 wt% semi-prepolymer and 9 wt% diluent, wherein the semi-prepolymer is prepared from isocyanate MDI-50 and polytetrahydrofuran diol. Component B consists of 50-60 wt% amino-terminated polyether, 38-48 wt% amine chain extender, 0-1 wt% filler, and 1 wt% defoamer, wherein the amino-terminated polyether is composed of polypropylene oxide diamine and polypropylene oxide triamine, and the amine chain extender is composed of dimethyl thiotoluene diamine (E300) and 4,4'-bis(sec-butylamino)-diphenylmethane (Unlink4200) in a molar ratio of 1:1 to 3:1. The filler is carbon nanotubes.

[0008] Preferably, the semi-prepolymer is prepared from 52-57 wt% isocyanate MDI-50 and 34-39 wt% polytetrahydrofuran diol.

[0009] Preferably, the polytetrahydrofuran diol has a functionality of 2 and a molecular weight of 2000.

[0010] Preferably, the terminal amino polyether has a functionality of 2 to 3 and a molecular weight of 2000 to 5000, and is composed of 46 to 52 wt% polyoxypropylene diamine and 4 to 8 wt% polyoxypropylene triamine.

[0011] Preferably, the average particle size of the carbon nanotubes is 5 to 10 micrometers.

[0012] Preferably, the functionality of the amine chain extender is 2.

[0013] The diluent described in this invention is a diluent commonly used in existing coating materials, such as propylene carbonate.

[0014] The defoamer described in this invention is a defoamer commonly used in existing coating materials, such as BYK066.

[0015] Preferably, component A is prepared as follows:

[0016] Polytetrahydrofuran diol was dehydrated at 120°C for 2 hours, then cooled to 80°C and reacted with isocyanate MDI-50 in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer was then reacted with a diluent for another hour, and after vacuuming, component A was obtained.

[0017] Preferably, component B is prepared as follows:

[0018] 50–60 wt% of amino-terminated polyether, 38–48 wt% of amine chain extender, 0–1 wt% of filler, and 1 wt% of defoamer are mixed at high speed in a reactor for at least 2 hours, and then vacuumed to obtain component B. The preparation method of the above-mentioned anti-explosion coating includes the following steps:

[0019] After preheating components A and B, with a volume ratio of 1:1, at 65℃~70℃ respectively, the components A and B are sprayed simultaneously using a spraying device to obtain an explosion-proof coating.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention uses E300 and Unlink4200 as chain extenders and carbon nanotubes as fillers. Since E300 and Unlink4200 are primary and secondary amines, respectively, they provide different hydrogen bond strengths. The carbon nanotube surface is rich in functional groups, readily forming hydrogen bonds with polymer molecules. Therefore, the coating material exhibits abundant intermolecular interactions, excellent mechanical properties, and strong protective capabilities under explosive impact loads. Furthermore, E300 and Unlink4200 possess sterically hindered structures, resulting in a longer gel time compared to chain extenders without sterically hindered structures, such as isoflurane diamine. This allows the coating material to achieve excellent mechanical properties without relying on specialized high-pressure spraying equipment; general-purpose two-component spraying equipment can be used, reducing the difficulty of application and increasing flexibility. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the explosion-proof test results of an embodiment of the present invention;

[0023] Figure 2 This is a comparison chart of the tensile properties of embodiments of the present invention. Detailed Implementation

[0024] 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.

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] In the following examples, all raw materials used are commercially available. Specifically, polytetrahydrofuran diol has a functionality of 2 and a molecular weight of 2000; polypropylene oxide diamine has a molecular weight of 2000; polypropylene oxide triamine has a molecular weight of 5000; the diluent is propylene carbonate; the filler is carbon nanotubes with an average particle size of 7 micrometers; and the defoamer is BYK066.

[0027] In the following embodiments, the coating performance is tested using the following methods:

[0028] After being placed under the conditions specified in GB9278 for 7 days, the coating performance was tested. The test standards for hardness, tensile strength, elongation at break, elastic modulus, and tear strength were GB / T529-2008. The coating material was sprayed onto a 0.5mm thick PMMA plate for explosion resistance testing, using 30% volume fraction hydrogen gas for the explosion test, according to T / CIESC 0019-2021.

[0029] Example 1

[0030] Preparation of component A: It consists of 91 wt% semi-prepolymer and 9 wt% diluent. First, 34 wt% polytetrahydrofuran glycol is dehydrated at 120℃ for 2 hours, then cooled to 80℃ and 57 wt% isocyanate MDI-50 is added. The mixture is reacted in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer is then reacted with 9 wt% diluent for 1 hour and then vacuumed.

[0031] Preparation of component B: 50 wt% polyoxypropylene diamine, 6 wt% polyoxypropylene triamine, 24 wt% E300, 18 wt% Unlink4200 (molar ratio of E300 to Unlink4200 is 2:1), 1 wt% filler and 1 wt% defoamer are mixed in a reactor and stirred at high speed for 2 h.

[0032] Coating preparation: Component A and component B with a volume ratio of 1:1 were preheated at 65℃~70℃ for 10 min, and then sprayed using a spraying device while mixing components A and B to obtain an explosion-proof coating.

[0033] Performance tests were conducted after the material was placed under the conditions specified in GB9278 for 7 days, and the results are shown in Table 1. Among these tests, the coating material was sprayed onto a 0.5 mm thick PMMA plate for explosion resistance testing, and an explosion test was performed using 30% hydrogen by volume. Figure 1This is a schematic diagram of the explosion resistance test results of the coating. The horizontal axis represents time and the vertical axis represents pressure. It can be seen that the uncoated PMMA board depressurizes and breaks in a very short time, while the coated PMMA board does not depressurize (prolongs the response time) and can effectively resist the explosion impact and remain intact.

[0034] Example 2

[0035] Preparation of component A: It consists of 91 wt% semi-prepolymer and 9 wt% diluent. First, 35 wt% polytetrahydrofuran glycol is dehydrated at 120℃ for 2 hours, then cooled to 80℃ and 56 wt% isocyanate MDI-50 is added. The mixture is reacted in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer is then reacted with 9 wt% diluent for 1 hour and then vacuumed.

[0036] Preparation of component B: 46 wt% polypropylene diamine and 4 wt% polypropylene triamine, 19.5 wt% E300, 28.5 wt% Unlink4200 (molar ratio of E300 and Unlink4200 is 1:1), 1 wt% filler, and 1 wt% defoamer were stirred at high speed in a reactor for 2 h.

[0037] Coating preparation: Component A and component B with a volume ratio of 1:1 were preheated at 65℃~70℃ for 10 min, and then sprayed using a spraying device while mixing components A and B to obtain an explosion-proof coating.

[0038] The performance test results are shown in Table 1.

[0039] Example 3

[0040] Preparation of component A: It consists of 91 wt% semi-prepolymer and 9 wt% diluent. First, 39 wt% polytetrahydrofuran glycol is dehydrated at 120℃ for 2 hours, then cooled to 80℃ and 52 wt% isocyanate MDI-50 is added. The mixture is reacted in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer is then reacted with 9 wt% diluent for 1 hour and then vacuumed.

[0041] Preparation of component B: 50 wt% polypropylene diamine, 5 wt% polypropylene triamine, 28.5 wt% E300, 14.5 wt% Unlink4200 (molar ratio of E300 to Unlink4200 is 3:1), 1 wt% filler, and 1 wt% defoamer were stirred at high speed in a reactor for 2 h.

[0042] Coating preparation: Component A and component B with a volume ratio of 1:1 were preheated at 65℃~70℃ for 10 min, and then sprayed using a spraying device while mixing components A and B to obtain an explosion-proof coating.

[0043] The performance test results are shown in Table 1.

[0044] Example 4

[0045] Preparation of component A: It consists of 91 wt% semi-prepolymer and 9 wt% diluent. First, 34 wt% polytetrahydrofuran glycol is dehydrated at 120℃ for 2 hours, then cooled to 80℃ and 57 wt% isocyanate MDI-50 is added. The mixture is reacted in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer is then reacted with 9 wt% diluent for 1 hour and then vacuumed.

[0046] Preparation of component B: 52 wt% polypropylene diamine, 8 wt% polypropylene triamine, 21.5 wt% E300, 16.5 wt% Unlink4200 (molar ratio of E300 to Unlink4200 is 2:1), 1 wt% filler, and 1 wt% defoamer were stirred at high speed in a reactor for 2 h.

[0047] Coating preparation: Component A and component B with a volume ratio of 1:1 were preheated at 65℃~70℃ for 10 min, and then sprayed using a spraying device while mixing components A and B to obtain an explosion-proof coating.

[0048] The performance test results are shown in Table 1.

[0049] Example 5

[0050] This embodiment is basically the same as Example 1, except that the amount of polyoxypropylene diamine added is 51 wt%, and no filler is added.

[0051] Comparative Example 1

[0052] This comparative example is basically the same as Example 5, except that the following components are added in different amounts: 32wt% polytetrahydrofuran diol, 59wt% isocyanate MDI-50, 30.5wt% E300, and 11.5wt% Unlink4200 (the molar ratio of E300 to Unlink4200 is 4:1).

[0053] As can be seen from Table 1, excessive addition of E300 will lead to brittle materials with low elongation at break.

[0054] Comparative Example 2

[0055] This comparative example is basically the same as Example 5, except that the following components are added in different amounts: 43 wt% polytetrahydrofuran diol, 48 wt% isocyanate MDI-50, 51 wt% polyoxypropylene diamine, 6 wt% E300, and 36 wt% Unlink4200 (the molar ratio of E300 to Unlink4200 is 1:4).

[0056] As can be seen from Table 1, adding too much Unlink4200 will result in low material strength.

[0057] Comparative Example 3

[0058] This comparative example is basically the same as Example 1, except that the following components are added in different amounts: 53 wt% polyoxypropylene diamine, 8 wt% polyoxypropylene triamine, 21.5 wt% E300, and 15.5 wt% Unlink4200 (the molar ratio of E300 to Unlink4200 is 2:1).

[0059] As can be seen from Table 1, a low proportion of chain extender leads to insufficient hydrogen bond density, poor energy consumption, and thus poor anti-explosion performance.

[0060] Comparative Example 4

[0061] This comparative example is basically the same as Example 1, except that the filler is carbon black.

[0062] As can be seen from Table 1, the performance of coatings with carbon black as filler is significantly worse than that of coatings with carbon nanotubes as filler. This is because the surface of carbon nanotubes is rich in functional groups and can form sufficient interaction forces with the polymer matrix, while carbon black has weak bonding force with the polymer matrix and is prone to agglomeration. In addition, carbon nanotubes themselves have excellent mechanical properties.

[0063] Comparative Example 5

[0064] Preparation of component A: It consists of 91 wt% semi-prepolymer and 9 wt% diluent. First, 25 wt% polytetrahydrofuran glycol is dehydrated at 120℃ for 2 h, then cooled to 80℃ and 66 wt% isocyanate MDI-50 is added. The mixture is reacted in a nitrogen atmosphere for 3 h. The resulting semi-prepolymer is then reacted with 9 wt% diluent for 1 h and then vacuumed.

[0065] Preparation of component B: 54 wt% polyoxypropylene diamine, 6 wt% polyoxypropylene triamine, 40 wt% isoflurane diamine, and 1 wt% defoamer were stirred at high speed in a reactor for 2 hours.

[0066] Coating preparation: Component A and component B with a volume ratio of 1:1 were preheated at 65℃~70℃ for 10 min, and then sprayed using a spraying device while mixing components A and B to obtain the coating.

[0067] As can be seen from Table 1, chain extenders without steric hindrance structures have short gel times and poor molding when using general spraying equipment, resulting in very poor performance.

[0068] Table 1: Performance test results.

[0069]

[0070] Figure 2This is a comparison chart of the tensile properties of the explosion-proof coating prepared in Example 1. (From...) Figure 2 As shown in Table 1, the coating formed by the method of the present invention has excellent mechanical properties. By using a reasonable ratio of E300 and Unlink4200 to provide different hydrogen bonds, carbon nanotubes and polyurea matrix form a hydrogen bond cross-linking network, which increases intermolecular interactions, improves the quasi-static and dynamic mechanical properties of the coating, and thus enhances its explosion-proof performance.

[0071] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An explosion-proof coating, characterized in that, The product consists of component A and component B in a volume ratio of 1:

1. Component A comprises 91 wt% semi-prepolymer and 9 wt% diluent, wherein the semi-prepolymer is prepared from isocyanate MDI-50 and polytetrahydrofuran diol. Component B comprises 50-60 wt% amino-terminated polyether, 38-48 wt% amine chain extender, 0-1 wt% filler, and 1 wt% defoamer, wherein the amino-terminated polyether is composed of polypropylene oxide diamine and polypropylene oxide triamine, and the amine chain extender is composed of dimethylthiotoluene diamine and 4,4-bis(sec-butylamino)-diphenylmethane in a molar ratio of 1:1 to 3:

1. The filler is carbon nanotubes.

2. The explosion-proof coating according to claim 1, characterized in that, The semi-prepolymer is prepared from 52-57 wt% isocyanate MDI-50 and 34-39 wt% polytetrahydrofuran diol.

3. The explosion-proof coating according to claim 1, characterized in that, Polytetrahydrofuran diol has a functionality of 2 and a molecular weight of 2000.

4. The explosion-proof coating according to claim 1, characterized in that, The terminal amino polyether has a functionality of 2-3 and a molecular weight of 2000-5000. The terminal amino polyether is composed of 46-52 wt% polyoxypropylene diamine and 4-8 wt% polyoxypropylene triamine.

5. The explosion-proof coating according to claim 1, characterized in that, The average particle size of carbon nanotubes is 5-10 micrometers.

6. The explosion-proof coating according to claim 1, characterized in that, The functionality of amine chain extenders is 2.

7. The explosion-proof coating according to claim 1, characterized in that, The diluent is propylene carbonate, and the defoamer is BYK066.

8. The explosion-proof coating according to claim 1, characterized in that, Component A is prepared as follows: Polytetrahydrofuran diol was dehydrated at 120°C for 2 hours, then cooled to 80°C and reacted with isocyanate MDI-50 in a nitrogen atmosphere for 3 hours. The resulting semi-prepolymer was then reacted with a diluent for another hour, and after vacuuming, component A was obtained.

9. The explosion-proof coating according to claim 1, characterized in that, The preparation of component B is as follows: 50-60 wt% of amino-terminated polyether, 38-48 wt% of amine chain extender, 0-1 wt% of filler, and 1 wt% of defoamer were mixed at high speed in a reactor for more than 2 hours, and then the mixture was vacuumed to obtain component B.

10. The method for preparing the explosion-proof coating according to any one of claims 1 to 9, characterized in that, Includes the following steps: After preheating components A and B, with a volume ratio of 1:1, at 65℃~70℃, they are sprayed simultaneously using a spraying device to obtain an explosion-proof coating.

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