Ultra-low temperature protective paint and protective coating thereof

Abstract

The present invention provides an ultra-low temperature protective coating and a protective coating thereof, wherein the protective coating comprises component A, wherein component A comprises an acrylic modified epoxy resin and a hyperbranched polymer toughening agent, wherein the hyperbranched polymer toughening agent is prepared by reacting 3-allyl-cyclooctene and a capping agent, wherein the molar ratio of the 3-allyl-cyclooctene to the capping agent is 10 to 30:1; and the capping agent comprises at least one of itaconic anhydride, glycidyl methacrylate, and glycidyl acrylate. A protective coating is also disclosed, wherein the protective coating is sprayed or rolled on a metal surface and dried to form a protective coating. The protective coating and protective coating prepared by the present invention can withstand an ultra-low temperature environment of 183°C, significantly improve the toughness and low temperature adhesion of the coating at ultra-low temperatures, and also have anti-salt spray, anti-humidity and anti-mildew functions, have high impact strength, and realize efficient protection of the protective coating.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to an ultra-low temperature protective coating and a protective coating thereof. Background Art

[0002] At present, insulation measures are required in the process of storage and transportation of ultra-low temperature liquids. The traditional method is to use foam insulation, which has complex manufacturing process and low production efficiency. For example, the new generation of carrier rockets use liquid oxygen / kerosene environmentally friendly fuel propellants, and the boiling point of liquid oxygen is as low as minus 183℃. The insulation structure of the liquid oxygen tank of domestic carrier rockets mostly uses polyurethane foam layer for insulation. However, this low-temperature protection structure design has low production efficiency and is difficult to meet the situation of high-density launch of carrier rockets.

[0003] For complex structural parts, organic coatings are often used for protection. In view of the different operating conditions of complex structural parts, the surface of my country's aerospace weapons and equipment is generally protected by various types of coatings, such as thermal control coatings, antistatic coatings, etc., which effectively ensure the service of aerospace weapons and equipment. However, so far, there are still challenges for organic coatings under ultra-low temperature (-183°C) conditions. The main reason is that polymer resins (including epoxy resins) shrink at low temperatures, the stress is large, and the coating is easy to break. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention provides an ultra-low temperature protective paint and protective coating to replace the traditional inefficient low-temperature protection structure and achieve high-quality and efficient protection in the form of a coating; and solves the problem that traditional organic coatings are difficult to withstand the use requirements under ultra-low temperature conditions.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides an ultra-low temperature protective coating, comprising component A, wherein component A comprises an acrylic modified epoxy resin and a hyperbranched polymer toughening agent, wherein the hyperbranched polymer toughening agent is prepared by reacting 3-allyl-cyclooctene and a capping agent, wherein the molar ratio of the 3-allyl-cyclooctene to the capping agent is 10 to 30:1; and the capping agent comprises at least one of itaconic anhydride, glycidyl methacrylate, and glycidyl acrylate.

[0007] The end of the end-capping agent contains a group that can react with an amine group. The anhydride group at the end of itaconic anhydride, and the epoxy group at the end of glycidyl methacrylate and glycidyl acrylate can react with the amine group and participate in the curing of the resin matrix. The prepared hyperbranched polymer toughening agent, the multi-free volume hyperbranched polymer containing a polyolefin core effectively absorbs and dissipates energy, and improves the ultra-low temperature resistance of the coating.

[0008] As some specific embodiments of the present invention, the 3-allyl-cyclooctene and the capping agent are reacted under the catalysis of Grubbs second-generation catalyst or Grubbs third-generation catalyst to prepare a hyperbranched polymer toughening agent, and the molar ratio of the 3-allyl-cyclooctene to the catalyst is 100:1 to 200:1.

[0009] As some specific embodiments of the present invention, when preparing the hyperbranched polymer toughening agent, the reaction is carried out in argon;

[0010] And / or, the reaction temperature is 25-60°C and the reaction time is 12-24 h.

[0011] As some specific embodiments of the present invention, the end-capping agent is itaconic anhydride, and the structural formula of the obtained hyperbranched polymer toughening agent is:

[0012] ,

[0013] Among them, m is 5-10 and n is 5-10.

[0014] As some specific embodiments of the present invention, the epoxy equivalent of the acrylic modified epoxy resin is 100-300 g / mol.

[0015] As some specific embodiments of the present invention, the component A includes, by mass percentage, 30-50% of an acrylic modified epoxy resin and 3-20% of a hyperbranched polymer toughening agent.

[0016] As some specific embodiments of the present invention, the component A also includes the following components, calculated by mass percentage: 20-30% talc, 5-10% titanium dioxide, 0.5-2% dispersant, 0.5-1% leveling agent, and 5%-25% diluent.

[0017] As some specific embodiments of the present invention, the mesh size of the talc is 100-400 mesh.

[0018] As some specific embodiments of the present invention, the mesh size of the titanium dioxide is 500-2000 mesh.

[0019] As some specific embodiments of the present invention, the dispersant is at least one of BYK-106, BYK-110, and BYK-180.

[0020] As some specific embodiments of the present invention, the leveling agent is at least one of Tego-450 and BYK-3441.

[0021] As some specific embodiments of the present invention, the ultra-low temperature protective coating further includes a component B, and the mass ratio of the component B to the component A is 1:2-3; in terms of mass percentage, the component B includes the following components:

[0022] Curing agent: 20~90%,

[0023] Diluent: 10%~80%.

[0024] As some specific embodiments of the present invention, the curing agent is a long-chain fatty curing agent, and the amine value of the long-chain fatty curing agent is 100-400 mg KOH / g.

[0025] Furthermore, the curing agent is at least one of Huntsman 3986, Huntsman 38-1, Hansman Chemical 8290, and Hansman Chemical 6870.

[0026] As some specific embodiments of the present invention, the diluent includes at least one of N,N-dimethylformamide, dimethylacetamide, tetrahydrofuran, methanol, ethanol, butanol, pentanol, and hexanol.

[0027] As some specific embodiments of the present invention, the protective coating can be applied to ultra-low temperature working conditions of minus 196°C.

[0028] As some specific embodiments of the present invention, the ultra-low temperature protective coating is prepared by the following preparation method:

[0029] S1. Add talcum powder, titanium dioxide, hyperbranched polymer toughening agent, dispersant, leveling agent and diluent gradually to acrylic modified epoxy resin according to the mass percentage content, and stir evenly at a speed of 50-150 r / min to form component A;

[0030] S2, dissolving the curing agent in the diluent to form component B;

[0031] S3. Mix component A and component B evenly at a stirring speed of 50-200 r / min to obtain a protective coating.

[0032] In a second aspect, the present invention provides an ultra-low temperature protective coating, which is prepared by spraying or rolling any of the ultra-low temperature protective coatings described above on a metal surface and drying it.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1) The protective coating and protective coating of the present invention first replace the traditional inefficient low-temperature protection structure, and achieve high-quality and efficient protection by preparing the protective coating into the form of a protective coating;

[0035] 2) The problem that traditional organic coatings are difficult to withstand the use requirements under ultra-low temperature conditions is solved. The protective coating of the present invention contains a hyperbranched toughening agent, which absorbs and dissipates energy through the cavity structure of the hyperbranched toughening agent, improves the ultra-low temperature resistance of the coating, and can also improve the compatibility of the coating's multiple components;

[0036] 3) The present invention realizes the preparation of a multifunctional protective coating that is ultra-low temperature resistant, salt fog resistant, moisture resistant, and mildew resistant through the synergistic effect between the resin and the filler, thereby achieving efficient protection of the heat-resistant coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0038] Figure 1 Schematic diagram of the structure of the hyperbranched polymer toughening agent synthesized in Examples 1-3;

[0039] Figure 2 This is a comparison chart of the flexibility and adhesion test results of the protective coatings in Example 6 and Comparative Example 6 at low temperatures, where 1mm and 2mm in the figure are the test conditions for low-temperature flexibility;

[0040] Figure 3 It is the infrared spectrum of the hyperbranched polymer toughening agent prepared in Example 1-3. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0042] Example 1

[0043] This embodiment provides a method for preparing a hyperbranched polymer toughening agent: 1 mmol of 3-allyl-cyclooctene is dissolved in 10 mL of tetrahydrofuran, and then 4.42 mg of Grubbs second-generation catalyst and 4.41 mg of itaconic anhydride are added, and the reaction is carried out under argon for 24 hours at a reaction temperature of 25°C, and a hyperbranched polymer toughening agent is obtained by precipitation. The conversion rate of the monomer is 46.6%, and the branching degree of the product is 25.9%. The structural schematic diagram of the prepared hyperbranched polymer toughening agent is shown in FIG. Figure 1 Its infrared spectrum is shown in Figure 3 shown.

[0044] Example 2

[0045] The Grubbs second generation catalyst in Example 1 was replaced by a Grubbs third generation catalyst, and the remaining conditions and steps were the same as in Example 1.

[0046] Example 3

[0047] Compared with Example 2, the reaction temperature was adjusted to 40°C, and the remaining steps were consistent with Example 2.

[0048] The structural formula of the hyperbranched toughening agent prepared in Examples 1-3 is as follows: Figure 1 As shown, the infrared spectrum is Figure 3 The reaction conditions and product structures are shown in Table 1 below.

[0049] Table 1 Reaction conditions and reaction products of Examples 1-3 for preparing hyperbranched toughening agents

[0050]

[0051] Example 4

[0052] The end-capping agent in Example 3 was replaced by 5.51 mg of glycidyl methacrylate from 4.41 mg of itaconic anhydride, and the remaining steps were the same as in Example 3 to obtain a hyperbranched polymer toughening agent. The conversion rate of the monomer was 52.7%, and the branching degree of the product was 33.7%.

[0053] Example 5

[0054] The end-capping agent in Example 3 was replaced by 5.51 mg of glycidyl acrylate from 4.41 mg of itaconic anhydride, and the remaining steps were the same as in Example 3 to obtain a hyperbranched polymer toughening agent. The conversion rate of the monomer was 55.7%, and the branching degree of the product was 37.2%.

[0055] According to the above results, the monomer conversion rate and branching degree of the polymer toughening agent prepared in Examples 3-5 are relatively high.

[0056] Comparative Examples 1-5

[0057] A different end-capping agent from that in Example 1-5 was used to prepare a hyperbranched polyolefin. Specifically, the end-capping agent in Example 3 was replaced by cis-2-butene-1,4-diol, dimethyl maleate, maleic acid, 1,4-dicyano-2-butene, and cis-4-octene, and the remaining steps were the same as in Example 3 to prepare a hyperbranched polyolefin. The specific results of the type and amount of the end-capping agent used in Comparative Examples 1-5, as well as the monomer conversion rate and product branching degree of the generated reaction product, are shown in Table 2.

[0058] Table 2 Monomer conversion rate and branching degree of hyperbranched polyolefins produced by reaction of comparative examples 1-5

[0059]

[0060] Embodiment 6-8

[0061] The hyperbranched polymer toughening agent prepared in Example 3 is used together with other components to prepare an ultra-low temperature protective coating, and the specific steps are as follows:

[0062] (1) titanium dioxide, talcum powder, the hyperbranched toughening agent prepared in Example 3, a dispersant, a leveling agent, and a diluent are gradually added to an acrylic modified epoxy resin, and stirred at a speed of 100 r / min to form component A;

[0063] (2) dissolving the curing agent in the diluent to form component B;

[0064] (3) mixing component A and component B uniformly at a stirring speed of 150 r / min to obtain a protective coating;

[0065] (4) The protective coating is sprayed onto the metal surface using a spraying process, and a protective coating is formed after drying.

[0066] The amount of the hyperbranched polymer toughening agent prepared in Example 3 in component A was adjusted to form Examples 6-8.

[0067] Examples 9-10

[0068] The hyperbranched polymer toughening agent in Examples 6-8 was replaced with the hyperbranched polymer toughening agent synthesized in Examples 4 and 5, and the remaining steps were carried out according to Examples 6-8 to form Examples 9 and 10.

[0069] Comparative Example 6

[0070] Compared with the ultra-low temperature protective coatings in Examples 6-10, no hyperbranched toughening agent is added to component A of Comparative Example 6, and the remaining components and steps are consistent with Examples 6-10.

[0071] Comparative Examples 7-11

[0072] The hyperbranched polymer toughening agents in Examples 6-10 were replaced with the hyperbranched polyolefins prepared in Comparative Examples 1-5, respectively, and the remaining steps and components were consistent with those in Examples 6-10.

[0073] The specific compositions of component A and component B in each embodiment and comparative example are shown in Table 3.

[0074] Table 3 Composition of component A and component B in each embodiment and comparative example

[0075]

[0076] In the above table, the dosage units of each component are all grams (g), the mesh size of titanium dioxide used in each embodiment and comparative example is 500 mesh, the mesh size of talc powder is 300 mesh, the dispersant in component A is BYK-110, the leveling agent is Tego-450, the curing agent in component B is Huntsman 3986, and the diluents in components A and B are all ethanol. The source of the acrylic modified epoxy resin in component A is the product CFU1955A of Weifang Fule New Materials Co., Ltd.

[0077] Effect Example

[0078] 1. The protective coatings prepared in Examples 6-10 and Comparative Examples 6-11 were sprayed on metal surfaces to form protective coatings, and the low-temperature flexibility, low-temperature adhesion, and impact strength of the prepared protective coatings were tested in accordance with GB-T 1731-1993, GB / T 9286-1998, and GB / T 1732-93. The density of the coatings was tested using the Archimedes drainage method.

[0079] 2. The protective coatings prepared in Examples 6-10 and Comparative Examples 6-11 were made into protective coatings, and the prepared coatings were tested for moisture and heat resistance, mildew resistance, and salt spray resistance according to GJB150.9A-2009, GJB150.10A-2009, and GJB150.11A-2009, respectively.

[0080] The performance test results are shown in Table 4 below.

[0081] Table 4 Test results of protective coating performance

[0082]

[0083] like Figure 2 The figure shows the flexibility and adhesion test results of Example 6 and Comparative Example 6 at low temperature (-196°C). It can be found that when the low-temperature flexibility of the low-temperature protective coating of Example 6 is tested at 1mm, its coating structure is still intact, while the protective coating of Comparative Example 6 is damaged when tested at 2mm. According to the low-temperature (-196°C) adhesion test results, Example 6 still has excellent adhesion at minus 196°C, and the test result is level 0, while the coating of Comparative Example 6 has tearing damage. Figure 2 From the data in the above table, it can be seen that the low-temperature toughness and low-temperature adhesion of Comparative Example 6 are significantly inferior to those of Example 6. When the low-temperature toughness of Examples 6-10 was tested at 1 mm, the coating structure was still intact, while the protective coatings of Comparative Examples 6, 8, 9, and 11 were damaged when the low-temperature toughness was tested at 2 mm, and the protective coatings of Comparative Examples 7 and 10 were damaged when the low-temperature toughness was tested at 3 mm.

[0084] According to the performance test results in Table 4, it can be seen that the low-temperature adhesion results of Comparative Examples 7-11 are slightly improved compared with Comparative Example 6, but are still significantly lower than the Examples. In addition, the impact strength test results of the coatings of the Examples are also significantly higher than those of the Comparative Examples, and the Examples passed the tests of salt spray resistance, moisture resistance, and mildew resistance, while the Comparative Examples failed to pass all the tests. Due to poor low-temperature toughness, the test results of the Comparative Examples are all lower than those of the Examples.

[0085] The above results show that the protective coating prepared by using the hyperbranched polyolefin in the comparative example has poor protective performance in a low temperature environment, while the use of the hyperbranched toughening agent in the present invention can greatly improve the low temperature protective performance of the protective coating. The hyperbranched toughening agent in the present application is a hyperbranched polyolefin containing anhydride or epoxy groups, which can improve the compatibility of multiple components of the coating; and it has a large free volume, and the cavity structure can effectively absorb and dissipate energy, reduce the low temperature volume strain of the coating, thereby greatly improving the low temperature protective performance of the coating.

[0086] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An ultra-low temperature protective coating, characterized in that: The invention comprises component A, wherein the component A comprises an acrylic modified epoxy resin and a hyperbranched polymer toughening agent, wherein the hyperbranched polymer toughening agent is prepared by reacting 3-allyl-cyclooctene and a capping agent, wherein the molar ratio of the 3-allyl-cyclooctene to the capping agent is 10 to 30:1; and the capping agent comprises at least one of itaconic anhydride, glycidyl methacrylate and glycidyl acrylate; The ultra-low temperature protective coating further comprises a component B, wherein the component B comprises a curing agent, and the curing agent is a long-chain fatty curing agent, and the amine value of the long-chain fatty curing agent is 100 to 400 mg KOH / g.

2. The ultra-low temperature protective coating according to claim 1, characterized in that: The 3-allyl-cyclooctene and the end-capping agent are reacted under the catalysis of Grubbs second-generation catalyst or Grubbs third-generation catalyst to prepare a hyperbranched polymer toughening agent, wherein the molar ratio of the 3-allyl-cyclooctene to the catalyst is 100:1 to 200:1; And / or, the reaction for preparing the hyperbranched polymer toughening agent is carried out in argon gas, the reaction temperature is 25-60° C., and the reaction time is 12-24 h.

3. The ultra-low temperature protective coating according to claim 1, characterized in that: The epoxy equivalent of the acrylic modified epoxy resin is 100-300 g / mol.

4. The ultra-low temperature protective coating according to claim 1, characterized in that: The component A comprises, by mass percentage, 30-50% of an acrylic acid-modified epoxy resin and 3-20% of a hyperbranched polymer toughening agent.

5. The ultra-low temperature protective coating according to claim 1, characterized in that: Calculated by mass percentage, the component A also includes the following components: 20-30% talc, 5-10% titanium dioxide, 0.5-2% dispersant, 0.5-1% leveling agent, and 5-25% diluent.

6. The ultra-low temperature protective coating according to claim 5, characterized in that: The mesh size of the talcum powder is 100 to 400 meshes; And / or, the mesh size of the titanium dioxide is 500-2000 mesh; And / or, the dispersant includes at least one of BYK-106, BYK-110, and BYK-180; And / or, the leveling agent includes at least one of Tego-450 and BYK-3441.

7. The ultra-low temperature protective coating according to claim 1, characterized in that: The mass ratio of component B to component A is 1:2-3; Calculated by mass percentage, the B component includes the following components: 20% to 90% of a curing agent, and 10% to 80% of a diluent.

8. The ultra-low temperature protective coating according to claim 5 or 7, characterized in that: The diluent includes at least one of N,N-dimethylformamide, dimethylacetamide, tetrahydrofuran, methanol, ethanol, butanol, pentanol, and hexanol.

9. An ultra-low temperature protective coating, characterized in that: The ultra-low temperature protective coating is prepared by spraying or rolling the ultra-low temperature protective coating as described in any one of claims 1 to 8 on a metal surface and drying the coating.

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