Low-temperature curing anti-corrosion primer for air conditioner aluminum fins and preparation method of low-temperature curing anti-corrosion primer

Abstract

The invention relates to the technical field of primer, in particular to low-temperature curing anti-corrosion primer for an air conditioner aluminum fin and a preparation method of the low-temperature curing anti-corrosion primer. The low-temperature curing anti-corrosion primer for the air conditioner aluminum fins is compounded by adopting modified epoxy resin and a curing agent; the preparation method comprises the following steps: treating hydroxylated graphene oxide by adopting a KH570 silane coupling agent and perfluorooctyltriethoxysilane, introducing unsaturated double bonds and a fluorine-containing siloxane chain segment into modified graphene oxide, reacting with a perfluorinated acrylate monomer and an amide monomer under the action of an initiator and an emulsifier, adding epoxy resin for reaction, and carrying out vacuum drying to obtain the fluorine-containing acrylate modified graphene oxide. Introducing the amido group and the modified graphene oxide of the fluorine-containing acrylate chain segment and the fluorine-containing siloxane chain segment into the modified epoxy resin respectively; through the process of combining the polymerization reaction, reactant diffusion control and other processes, the curing temperature of the aluminum fin anticorrosion prime coat is reduced to 150-200 DEG C on the basis that the performance is not reduced.

Description

Technical Field

[0001] The invention relates to the technical field of primers, in particular to a low-temperature curing anti-corrosion primer for air conditioner aluminum fins and a preparation method thereof. Background Art

[0002] The fins of air conditioner heat exchangers are made of densely packed sheets of aluminum foil approximately 0.1mm thick. During use, these sheets gradually develop "water bridges," white powder, and an unpleasant odor, seriously reducing air conditioner efficiency and significantly impacting health. To cost-effectively address these issues, domestic and international manufacturers typically coat the aluminum foil with a hydrophilic protective material.

[0003] Air conditioner radiators use aluminum fins for heat dissipation. To improve the heat dissipation efficiency of the aluminum fins, they are typically coated with two layers of coating: one for corrosion protection and the other for hydrophilicity. The anti-corrosion primer is typically applied with a resin such as acrylic or epoxy. After coating, the hydrophilic primer on the air conditioner fins is typically cured at high temperatures. Acrylic resins, in particular, are cured at a peak substrate temperature (PMT) of 232°C to 254°C. This high-temperature curing requires high energy consumption. Furthermore, the high tension on the aluminum foil during roller coating can easily cause the coil to break at high temperatures, leading to production stoppages and wasted materials and time.

[0004] In order to reduce the curing temperature of the primer for air conditioner aluminum fins, it is necessary to provide a method for low-temperature curing of resins, which can not only reduce the peak substrate temperature (PMT) during coating, but also ensure that the aluminum fins after coating have good corrosion resistance and hydrophilic properties. Summary of the Invention

[0005] Therefore, there is a need for a low-temperature curing anti-corrosion primer for air conditioner aluminum fins. This primer allows for a lower curing temperature during coating, and also ensures that the cured primer exhibits relatively good anti-corrosion and hydrophilic properties. The low-temperature curing method for aluminum fins provided by this invention also reduces coating energy consumption, lowers tension on the aluminum foil, reduces the risk of coil breakage, improves production efficiency, and reduces costs.

[0006] One object of the present invention is to provide a low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0007] 45-65 parts of modified epoxy resin

[0008] 30-50 parts of curing agent

[0009] 0.5-5 parts of additives;

[0010] The modified epoxy resin is obtained by reacting perfluoroacrylate monomer, amide monomer, epoxy resin and modified graphene oxide;

[0011] The modified graphene oxide is obtained by reacting graphene oxide with tridecafluorooctyltriethoxysilane and KH570.

[0012] Furthermore, the perfluoroacrylate monomer is selected from one or more of perfluoropolyether acrylate, perfluorohexylethyl acrylate, and perfluorobutylethyl methacrylate.

[0013] Furthermore, the epoxy resin is selected from one or more of epoxy resin E-44, epoxy resin E-51, and epoxy resin 6101.

[0014] Furthermore, the auxiliary agent is selected from one or more of a defoaming agent, a dispersant, and a leveling agent.

[0015] Furthermore, the curing agent is selected from one or more of acrylic resin curing agents, amide resin cross-linking agents, and organotin drying agents.

[0016] Furthermore, the amide cross-linking agent includes one or more of boric acid and borax.

[0017] The present invention also provides a method for preparing the low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following steps:

[0018] S1, adding hydroxylated graphene oxide, tridecafluorooctyltriethoxysilane, and KH570 to a solvent, heating and reacting to obtain modified graphene oxide;

[0019] S2. Under the protection of an inert gas, a perfluoroacrylate monomer, an amide monomer, an epoxy resin, and modified graphene oxide are blended, an initiator and an emulsifier are added, and the mixture is heated for reaction to obtain a modified epoxy resin;

[0020] S3. Evenly mix the modified epoxy resin with other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0021] Furthermore, in step S1, the temperature of the heating reaction is 80-90°C.

[0022] Furthermore, in step S2, the temperature of the heating reaction is 85-95°C.

[0023] The present invention has the following beneficial effects:

[0024] The low-temperature curing anti-corrosion primer for air-conditioning aluminum fins of the present invention is compounded with modified epoxy resin and curing agent; first, hydroxylated graphene oxide is treated with KH570 silane coupling agent and tridecafluorooctyl triethoxysilane, and unsaturated double bonds and fluorine-containing siloxane segments are introduced into the modified graphene oxide, and then reacted with perfluoroacrylate monomers and amide monomers under the action of an initiator and an emulsifier, and then epoxy resin is added for reaction, so that the modified graphene oxide containing amide groups, fluorine-containing acrylate segments and fluorine-containing siloxane segments are respectively introduced into the modified epoxy resin; on the one hand, since the modified graphene oxide introduces fluorine-containing siloxane segments, which are similar in polarity to components such as perfluoroacrylate monomers and amide monomers, the compatibility of the modified graphene oxide in the components can be effectively improved, and the agglomeration of the modified graphene oxide during the reaction can be avoided, and the modified graphene oxide not only has ultra-high specific surface area and barrier properties, but also has fluorine-containing siloxane segments that can The invention can give the primer a low surface energy and chemical inertness, form a hydrophobic surface on the surface of the primer, and form a dense physical barrier, effectively isolating the penetration of water, oxygen and corrosive media, and effectively improving the corrosion resistance of the anti-corrosion primer; secondly, the introduced perfluoroacrylate monomer and acrylamide form an amphiphilic structure, which can balance the hydrophobicity brought by the fluorine-containing segment and adjust the hydrophilicity of the primer, so that the primer has certain hydrophilic properties; the polar groups of acrylamide are cross-linked with the oxygen-containing group network in the epoxy resin and modified graphene oxide through hydrogen bonds, thereby enhancing the phase interface bonding; and the flexibility of the fluorine-containing segment reduces the internal stress of the coating, reduces the tension when coated on the aluminum foil, reduces the risk of breakage, improves production efficiency and reduces costs; in addition, the present invention reduces the curing temperature of the aluminum fin anti-corrosion primer, i.e., the peak substrate temperature (PMT), to 150-200°C without reducing the performance through a process combining polymerization reaction, reactant diffusion control and other processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the TGA graph of the primers of Examples 1-5 during curing. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0027] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0028] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0029] Epoxy resin, epoxy resin E44. Hydroxylated graphene oxide, purchased from Xi'an Qiyue Biological. TDI, toluene diisocyanate, TDI-80 curing agent, purchased from Shandong Shengcang Chemical Technology Co., Ltd. Leveling agent, BYK300. Dispersant, BYK110. Defoamer, BYK052. KH570, γ-methacryloyloxypropyltrimethoxysilane.

[0030] Example 1

[0031] A low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0032]

[0033] The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps:

[0034] S1, adding 40 parts of hydroxylated graphene oxide, 10 parts of tridecafluorooctyltriethoxysilane, 10 parts of KH570 and 3 parts of distilled water to 60 parts of anhydrous ethanol, heating to 85 ° C. for 5 hours, washing with deionized water three times, and drying to obtain modified graphene oxide;

[0035] S2. Under the protection of nitrogen, 160 parts of perfluorohexylethyl acrylate, 100 parts of 50wt% acrylamide solution and 10 parts of modified graphene oxide were added to 50 parts of deionized water and blended, 2 parts of potassium persulfate and 8 parts of sodium dodecylbenzenesulfonate were added, and the mixture was heated to 90°C for 2h. The pH value of the system was adjusted to 9 with 1wt% sodium hydroxide solution, and 12 parts of epoxy resin were added, and the mixture was stirred for 1h to obtain a modified epoxy resin;

[0036] S3-1, adding 28 parts of TDI, 4 parts of boric acid and 8 parts of dibutyltin dilaurate to 90 parts of ether, stirring at 30° C. for 50 minutes to obtain the curing agent;

[0037] S3-2. Mix the modified epoxy resin, curing agent and other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0038] Example 2

[0039] A low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0040]

[0041] The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps:

[0042] S1, adding 40 parts of hydroxylated graphene oxide, 10 parts of tridecafluorooctyltriethoxysilane, 10 parts of KH570 and 3 parts of distilled water to 60 parts of anhydrous ethanol, heating to 85 ° C. for 5 hours, washing with deionized water three times, and drying to obtain modified graphene oxide;

[0043] S2. Under the protection of nitrogen, 160 parts of perfluorohexyl ethyl acrylate, 100 parts of 50 wt% acrylamide solution and 10 parts of modified graphene oxide were added to 50 parts of deionized water and blended, 2 parts of potassium persulfate and 8 parts of sodium dodecylbenzene sulfonate were added, and the mixture was heated to 90° C. for 2 h. The pH value of the system was adjusted to 9 with 1 wt% sodium hydroxide solution, and 8 parts of epoxy resin were added, and the mixture was stirred for 1 h to obtain a modified epoxy resin;

[0044] S3-1, adding 28 parts of TDI, 4 parts of boric acid and 8 parts of dibutyltin dilaurate to 90 parts of ether, stirring at 30° C. for 50 minutes to obtain the curing agent;

[0045] S3-2. Evenly mix the modified epoxy resin, curing agent and other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0046] Example 3

[0047] A low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0048]

[0049]

[0050] The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps:

[0051] S1, adding 40 parts of hydroxylated graphene oxide, 10 parts of tridecafluorooctyltriethoxysilane, 10 parts of KH570 and 3 parts of distilled water to 60 parts of anhydrous ethanol, heating to 85 ° C. for 5 hours, washing with deionized water three times, and drying to obtain modified graphene oxide;

[0052] S2. Under the protection of nitrogen, 160 parts of perfluorohexyl ethyl acrylate, 100 parts of 50 wt% acrylamide solution and 10 parts of modified graphene oxide were added to 50 parts of deionized water and blended, 2 parts of potassium persulfate and 8 parts of sodium dodecylbenzenesulfonate were added, and the mixture was heated to 90° C. for 2 h. The pH value of the system was adjusted to 9 with 1 wt% sodium hydroxide solution, and 16 parts of epoxy resin were added, and the mixture was stirred for 1 h to obtain a modified epoxy resin;

[0053] S3-1, adding 28 parts of TDI, 4 parts of boric acid and 8 parts of dibutyltin dilaurate to 90 parts of ether, stirring at 30° C. for 50 minutes to obtain the curing agent;

[0054] S3-2. Evenly mix the modified epoxy resin, curing agent and other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0055] Example 4

[0056] A low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0057]

[0058] The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps:

[0059] S1, adding 40 parts of hydroxylated graphene oxide, 10 parts of tridecafluorooctyltriethoxysilane, 10 parts of KH570 and 3 parts of distilled water to 60 parts of anhydrous ethanol, heating to 85 ° C. for 5 hours, washing with deionized water three times, and drying to obtain modified graphene oxide;

[0060] S2. Under the protection of nitrogen, 160 parts of perfluorohexylethyl acrylate, 100 parts of 50wt% acrylamide solution and 10 parts of modified graphene oxide were added to 50 parts of deionized water and blended, 2 parts of potassium persulfate and 8 parts of sodium dodecylbenzenesulfonate were added, and the mixture was heated to 90°C for 2h. The pH value of the system was adjusted to 9 with 1wt% sodium hydroxide solution, and 12 parts of epoxy resin were added, and the mixture was stirred for 1h to obtain a modified epoxy resin;

[0061] S3-1, adding 28 parts of TDI, 4 parts of boric acid and 8 parts of dibutyltin dilaurate to 90 parts of ether, stirring at 30° C. for 50 minutes to obtain the curing agent;

[0062] S3-2. Evenly mix the modified epoxy resin, curing agent and other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0063] Example 5

[0064] A low-temperature curing anticorrosive primer for air conditioner aluminum fins, comprising the following components in parts by mass:

[0065]

[0066] The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps:

[0067] S1, adding 40 parts of hydroxylated graphene oxide, 10 parts of tridecafluorooctyltriethoxysilane, 10 parts of KH570 and 3 parts of distilled water to 60 parts of anhydrous ethanol, heating to 85 ° C. for 5 hours, washing with deionized water three times, and drying to obtain modified graphene oxide;

[0068] S2. Under the protection of nitrogen, 160 parts of perfluorohexylethyl acrylate, 100 parts of 50wt% acrylamide solution and 10 parts of modified graphene oxide were added to 50 parts of deionized water and blended, 2 parts of potassium persulfate and 8 parts of sodium dodecylbenzenesulfonate were added, and the mixture was heated to 90°C for 2h. The pH value of the system was adjusted to 9 with 1wt% sodium hydroxide solution, and 12 parts of epoxy resin were added, and the mixture was stirred for 1h to obtain a modified epoxy resin;

[0069] S3-1, adding 28 parts of TDI, 4 parts of boric acid and 8 parts of dibutyltin dilaurate to 90 parts of ether, stirring at 30° C. for 50 minutes to obtain the curing agent;

[0070] S3-2. Evenly mix the modified epoxy resin, curing agent and other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

[0071] Comparative Example 1

[0072] An anti-corrosion primer. The difference between this comparative example and Example 1 is that in step S2, perfluorohexylethyl acrylate is replaced by methacrylic acid, and other components and preparation methods are the same.

[0073] Comparative Example 2

[0074] An anti-corrosion primer. The difference between this comparative example and Example 1 is that step S1 is removed, that is, in step S2, the modified graphene oxide is removed, and the other components and preparation methods are the same.

[0075] Comparative Example 3

[0076] An anti-corrosion primer. The difference between this comparative example and Example 1 is that step S1 is removed and the modified graphene oxide is replaced by graphene oxide. Other components and preparation methods are the same.

[0077] Test Example 1

[0078] The primers prepared in Examples 1-5 were coated on aluminum foil and then cured in an oven at 150-200° C. for 30 seconds. The curing temperature of the primers was then tested.

[0079] The test results are as follows Figure 1 As shown in the figure, it can be seen that the primer curing process mainly occurs in the range of 150-200℃.

[0080] Test Example 2

[0081] The primers prepared in Examples 1-5 and Comparative Examples 1-3 were coated on aluminum foil, baked and cured in an oven at 180° C. for 30 seconds, and then tested for salt spray resistance according to the neutral salt spray test conditions of 10.1 in GB / T 10125-2021;

[0082] The water resistance is tested using the immersion test method in 9.1 of GB-T1733-1993.

[0083] The difference between the indicators of each group and those of Example 1 was calculated. The test results are shown in Table 1.

[0084] Table 1 Performance test results of primers of Examples 1-5 and Comparative Examples 1-3

[0085] Serial number Water resistance (h) Salt spray resistance (h) △ Water resistance (h) △Salt spray resistance (h) Example 1 1700 560 0 0 Example 2 1500 550 -200 -10 Example 3 1500 570 -200 10 Example 4 1600 580 -100 20 Example 5 1500 570 -200 10 Comparative Example 1 1300 520 -400 -40 Comparative Example 2 1150 510 -550 -50 Comparative Example 3 1000 490 -700 -70

[0086] According to Table 1, it can be concluded that the water resistance and salt spray resistance of Examples 1-5 are better than those of Comparative Examples 1-3 as a whole. Among them, the water resistance of Example 1 is the best, reaching 1700h, and the salt spray resistance is 560h. It can be seen that the primer product of the present invention can not only be cured at low temperature, but also has very good corrosion resistance, and is suitable for the application of air-conditioning aluminum fins. The water resistance of Examples 2, 3, and 5 is 1500h, and the salt spray resistance is between 560-580h, and the performance is relatively close. In the comparative examples, the water resistance and salt spray resistance show a downward trend as the number increases, and the two indicators of Comparative Example 3 are the lowest, at 1000h and 490h respectively. Overall, the primer of the embodiment performs better in water resistance and salt spray resistance, has better stability, and the performance of the comparative example is relatively weak.

[0087] 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 embodied 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 illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0088] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A low-temperature curing anticorrosive primer for air conditioner aluminum fins, characterized in that: The composition includes the following components in parts by weight: 45-65 parts of modified epoxy resin 30-50 parts of curing agent 0.5-5 parts of additives; The modified epoxy resin is obtained by reacting perfluoroacrylate monomer, amide monomer, epoxy resin and modified graphene oxide; The modified graphene oxide is obtained by reacting graphene oxide with tridecafluorooctyltriethoxysilane and KH570.

2. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 1, characterized in that: The perfluoroacrylate monomer is selected from one or more of perfluoropolyether acrylate, perfluorohexylethyl acrylate, and perfluorobutylethyl methacrylate.

3. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 1, characterized in that: The amide monomer is selected from one or more of acrylamide, methacrylamide, and isopropyl acrylamide.

4. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 1, characterized in that: The epoxy resin is selected from one or more of epoxy resin E-44, epoxy resin E-51, and epoxy resin 6101.

5. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 1, characterized in that: The auxiliary agent is selected from one or more of a defoaming agent, a dispersant, and a leveling agent.

6. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 1, characterized in that: The curing agent is selected from one or more of acrylic resin curing agents, amide resin cross-linking agents, and organotin drying agents.

7. The low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 6, characterized in that: The amide cross-linking agent includes one or more of boric acid and borax.

8. The method for preparing the low-temperature curing anticorrosive primer for air conditioner aluminum fins according to any one of claims 1 to 7, characterized in that: The preparation method of the low-temperature curing anticorrosive primer for air conditioner aluminum fins comprises the following steps: S1, adding hydroxylated graphene oxide, tridecafluorooctyltriethoxysilane, and KH570 to a solvent, heating and reacting to obtain modified graphene oxide; S2. Under the protection of an inert gas, a perfluoroacrylate monomer, an amide monomer, an epoxy resin, and modified graphene oxide are blended, an initiator and an emulsifier are added, and the mixture is heated for reaction to obtain a modified epoxy resin; S3. Evenly mix the modified epoxy resin with other ingredients to obtain a low-temperature curing anti-corrosion primer for air conditioner aluminum fins.

9. The method for preparing the low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 8, characterized in that: In step S1, the temperature of the heating reaction is 80-90°C.

10. The method for preparing the low-temperature curing anticorrosive primer for air conditioner aluminum fins according to claim 8, characterized in that: In step S2, the temperature of the heating reaction is 85-95°C.

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