Self-repairing coating and its application, and deicing material

Abstract

The present application relates to a kind of self-repairing coating and its application, anti-icing material.The self-repairing coating includes DA resin, mercapto curing agent and light base generator;The DA resin has the structure as shown in formula I.R1It is the divalent radical from polymeric dihydric alcohol;R3It is the divalent radical containing ester group of C1-C10 or the divalent radical containing ether bond of C1-C10;n1, n2 each independently is integer greater than or equal to 0.The present application selects DA resin as the material of self-repairing coating, when coating is damaged, temperature is heated to above heat-sensitive point or under the condition of solar irradiation, furfuryl alcohol is removed from maleimide ring, crosslinking system is released, coating is soft and flat, and damaged position is automatically repaired.Mercapto and double bond are crosslinked, and the strength is higher at room temperature, while reaching repair rheological point, can be simply supplemented with hydrophobic anti-icing material, compared with conventional self-repairing material, more repair times can be obtained.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a self-healing coating and its application, and an anti-icing material. Background Technology

[0002] Currently, self-healing coatings can be divided into exogenous self-healing and intrinsic self-healing. Exogenous self-healing generally refers to repairing damaged areas using external repair agents such as microcapsules, nanotubes, and hollow fibers, while intrinsic self-healing repairs damaged areas by altering the fluidity of the coating itself through reversible chemical bonds. Superhydrophobic anti-icing coatings have become a hot topic in recent years. For power lines and poles in high-altitude or cold northern regions that are prone to icing, electrical facilities and supporting structures are often damaged during cold waves. Hydrophobic anti-icing coatings can effectively reduce the adhesion of ice and water, while accelerating de-icing, thereby protecting building materials and the safety of local residents.

[0003] CN110396308A discloses a self-healing anti-icing coating with a micro-nano porous structure, which can prolong the freezing time and reduce the adhesion between ice and the coating. CN108893070A discloses a thermally-driven low-temperature anti-icing film, including a photothermal layer and a self-healing superhydrophobic layer, combining active and passive anti-icing methods to improve the anti-icing effect. CN109762453A discloses a design method for preparing a bio-based superhydrophobic anti-icing coating using renewable biomass resources as raw materials, which reduces the use of petroleum products while achieving superhydrophobic properties.

[0004] However, most current methods for preparing superhydrophobic coatings have limited re-repair capabilities. Furthermore, natural environments such as rain, dust accumulation, oxygen oxidation, and friction from various objects can damage the micro- and nano-structures of materials or increase their surface energy. Therefore, developing a re-repairable anti-icing material has become an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention develops a self-healing coating and its application, as well as an anti-icing material.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a self-healing coating, the self-healing coating comprising DA resin, mercapto curing agent and photoalkali generator;

[0008] The DA resin has the structure shown in Formula I:

[0009]

[0010] R1 is a divalent group derived from a polymeric diol;

[0011] R2 is a divalent group containing an aromatic structure, such as C6-C30, C7, C8, C10, C12, C15, C18, C20 or C25, etc.

[0012] R3 is a C1-C10 divalent group containing an ester group or a C1-C10 divalent group containing an ether bond;

[0013] The divalent groups containing ester groups in C1-C10 can be divalent groups containing ester groups (-COO- or -OCO-) such as C2, C4, C6 or C8.

[0014] Divalent groups containing ether bonds in C1-C10, such as divalent groups containing ether bonds (-O-) in C2, C4, C6 or C8, etc.

[0015] n1 and n2 are each independent integers greater than or equal to 0, such as 1, 2, 3, 4 or 5.

[0016] The self-healing coating provided by this invention comprises a DA resin with a specific structure, a thiol curing agent, and a photo-alkali generator. The double bonds in the DA resin and the thiol groups in the thiol curing agent can undergo a curing reaction under the catalysis of the photo-alkali generator to form a self-healing coating. This self-healing coating can be repeatedly repaired compared to traditional self-healing coatings. This invention selects DA resin as the material for the self-healing coating. When the coating is damaged, heating it above its thermosensitive point or exposing it to sunlight causes furfuryl alcohol to detach from the maleimide ring, breaking the cross-linking system, softening and leveling the coating, and automatically repairing the damaged area. After the temperature drops to room temperature, furfuryl alcohol re-bonds with the maleimide ring, completing the repair. Furthermore, due to its cross-linking with double bonds using thiol groups, it exhibits high strength at room temperature. Simultaneously, reaching the repair rheological point allows for the simple addition of hydrophobic anti-icing materials, resulting in more repair cycles compared to conventional self-healing materials.

[0017] Preferably, R1 is selected from any of the following structures:

[0018]

[0019] in, Indicates the linkage site of the functional group;

[0020] n3, n4, n5, n6, n7, and n8 are each independent integers between 5 and 35, for example, they can be 10, 15, 20, 25, or 30, etc.

[0021] Preferably, R2 is Indicates the linking site of a functional group.

[0022] Preferably, R3 is selected from any of the following structures.

[0023] Indicates the linkage site of the functional group;

[0024] Preferably, the number average molecular weight of the DA resin is 1000-5000 g / mol, for example, it can be 1200 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 2800 g / mol, 3000 g / mol, 3300 g / mol, 3500 g / mol, 4000 g / mol, 4300 g / mol, 4500 g / mol or 4800 g / mol, etc.

[0025] Preferably, the DA resin is prepared by the following method, the method comprising:

[0026] (1) The polymer diol and isophorone diisocyanate were reacted under the catalysis of dibutyltin dilaurate to obtain the first intermediate with isocyanate group end capping.

[0027] (2) The first intermediate is reacted with DA monomer to obtain a hydroxyl-terminated second intermediate;

[0028] The structural formula of the DA monomer is as follows:

[0029] R2 has the same defined range as in Equation I;

[0030] (3) The second intermediate reacts with isophorone diisocyanate under the catalysis of dibutyltin dilaurate to obtain a third intermediate with isocyanate group end capping.

[0031] (4) The third intermediate reacts with the capping agent to obtain the DA resin;

[0032] The structure of the capping agent is as follows: R3 has the same defined range as in Equation I.

[0033] Preferably, the reaction temperatures in steps (1), (2), (3), and (4) are each independently 40-60°C, such as 42°C, 45°C, 47°C, 50°C, 52°C, 55°C, or 57°C.

[0034] Preferably, the reaction time in steps (1), (2), (3), and (4) is 3-5 hours, for example, 3.5 hours, 3.7 hours, 4 hours, 4.2 hours, or 4.5 hours.

[0035] Preferably, the reactions described in steps (1) and (3) are carried out under stirring conditions.

[0036] Preferably, the stirring speed of the reaction in steps (1) and (3) is 1000-2000 rpm, for example, 1200 rpm, 1400 rpm, 1600 rpm or 1800 rpm.

[0037] Preferably, the molar ratio of isophorone diisocyanate to polymeric diol in step (1) is (1.5-2.5):1, for example, 1.7:1, 1.9:1, 2:1, 2.2:1 or 2.4:1.

[0038] Preferably, the molar ratio of the DA monomer to the first intermediate in step (2) is (1.5-2.5):1, such as 1.7:1, 1.9:1, 2:1, 2.2:1 or 2.4:1.

[0039] Preferably, the molar ratio of isophorone diisocyanate to the second intermediate in step (3) is (1.5-2.5):1, for example, 1.7:1, 1.9:1, 2:1, 2.2:1 or 2.4:1.

[0040] Preferably, the molar ratio of the capping agent to the third intermediate in step (4) is (1.5-2.5):1, for example, 1.7:1, 1.9:1, 2:1, 2.2:1 or 2.4:1, etc.

[0041] Preferably, the mass ratio of dibutyltin dilaurate to isophorone diisocyanate in steps (1) and (3) is 1:(5-20), for example, 1:8, 1:9, 1:10, 1:11, 1:12, 1:15 or 1:18, etc.

[0042] Preferably, before step (1) begins, all reactants are dehydrated.

[0043] Preferably, nitrogen protection is provided during the reaction processes in steps (1), (2), (3) and (4).

[0044] In the synthesis of DA resin, this invention uses isophorone diisocyanate (IPDI) as a raw material. By utilizing the different activities of the isocyanate groups at both ends of IPDI under the catalyst of dibutyltin dilaurate, IPDI is added stepwise for programmed synthesis, which can obtain a more symmetrical DA resin, improve the regularity of molecular chains in the coating film, and enhance the strength of the coating film.

[0045] Preferably, the mercapto curing agent comprises trimethylolpropane tris(3-mercaptopropionate).

[0046] Preferably, the mass ratio of the DA resin to the mercapto curing agent is (5-15):1, for example, 6:1, 7:1, 9:1, 10:1 or 12:1.

[0047] Preferably, the photoalkali generator is obtained by reacting an organic base with a photoalkali-producing salt.

[0048] Preferably, the preparation method of the photo-alkali generator includes the following steps:

[0049] The organic base reacts with the photoalkali-producing salt to obtain the photoalkali generator.

[0050] Preferably, the organic base needs to be dissolved in an acidic solution before reacting with the photo-alkali-producing salt.

[0051] Preferably, the acidic solution includes any one or a combination of at least two of hydrochloric acid solution, sulfuric acid solution or nitric acid solution, and more preferably hydrochloric acid solution.

[0052] Preferably, the organic base includes any one or a combination of at least two of triethylamine, tributylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene or 1,5,7-trizabicyclo[4.4.0]decene-5-ene.

[0053] Preferably, the photo-alkali-producing salt comprises sodium tetraphenylborate.

[0054] Preferably, the mass ratio of the DA resin to the photo-alkali generator is (50-150):1, such as 60:1, 80:1, 100:1, 120:1 or 140:1.

[0055] Preferably, the self-healing coating further includes a photosensitizer.

[0056] In this invention, adding a photosensitizer to the self-healing coating can enhance the coating's light absorption capacity and energy transfer, thereby enhancing the anti-icing effect.

[0057] Preferably, the photosensitizer includes any one or a combination of at least two of 2-isopropylthioxanthonone, 4-isopropylthioxanthonone, 2-chlorothioxanthonone, or benzophenone.

[0058] Preferably, the mass ratio of the DA resin to the photosensitizer is (150-250):1, such as 160:1, 180:1, 200:1, 220:1 or 240:1.

[0059] Preferably, the self-healing coating also includes a free radical polymerization inhibitor.

[0060] This invention incorporates a free radical polymerization inhibitor when compounding DA resin. This inhibitor suppresses the free radical polymerization of double bonds and promotes the click reaction between double bonds and thiol groups, ensuring that all double bonds undergo the click reaction with thiol groups. This results in an anti-icing coating with higher strength, less susceptibility to wrinkling, and controllable reaction rate. Furthermore, the addition of the free radical polymerization inhibitor optimizes reaction conditions, allowing the reaction to proceed in a mild environment, and even enabling a dark reaction to continue after the light reaction, thus ensuring complete cross-linking of the coating film.

[0061] Preferably, the mass ratio of the free radical polymerization inhibitor to the photosensitizer is 1:(0.3-3), such as 1:0.5, 1:0.7, 1:1, 1:1.5 or 1:2.

[0062] In this invention, if the mass ratio of free radical polymerization inhibitor to photosensitizer is too large or too small, an anti-icing coating with excellent strength cannot be obtained.

[0063] Preferably, the free radical polymerization inhibitor comprises 2,2,6,6-tetramethylpiperidine-N-oxy radical and / or butylated hydroxytoluene.

[0064] Preferably, the self-healing coating also includes a solvent.

[0065] Preferably, the solvent includes acetone.

[0066] Preferably, the solid content of the self-healing coating is 40%-60%, for example, it can be 42%, 45%, 50%, 55% or 58%, etc.

[0067] In a second aspect, the present invention provides an anti-icing coating, the anti-icing coating comprising agent A, agent B and agent C, agent A comprising the self-healing coating as described in the first aspect, agent B comprising photothermal filler, and agent C comprising superhydrophobic filler.

[0068] This invention incorporates a combination of photothermal filler, superhydrophobic filler, and self-healing coating. Upon heating, the coating formed by the self-healing coating softens, and the superhydrophobic filler and self-healing coating interpenetrate, improving the coating's anti-icing effect. Because the photothermal filler has a photothermal effect, under good sunlight conditions, the coating absorbs light energy directly to its rheological heat-sensitive point, allowing it to self-flow, repair damage, and accelerate de-icing.

[0069] Preferably, agents A, B, and C are each packaged independently.

[0070] Preferably, the photothermal filler comprises superhydrophobic carbon nanotubes.

[0071] In this invention, superhydrophobic carbon nanotubes are selected as photothermal fillers, which can further improve the anti-icing effect of the coating.

[0072] Preferably, agent B further includes a solvent.

[0073] Preferably, the solvent includes petroleum ether.

[0074] Preferably, the mass percentage of photothermal filler in agent B is 2%-10%, for example, it can be 3%, 4%, 5%, 7% or 9%, etc.

[0075] Preferably, the superhydrophobic filler comprises superhydrophobic silica.

[0076] Preferably, agent C further includes a solvent.

[0077] Preferably, the solvent includes petroleum ether.

[0078] Preferably, the superhydrophobic filler content in agent C is 2%-10% by mass, for example, it can be 3%, 4%, 5%, 7% or 9%.

[0079] Thirdly, the present invention provides an anti-icing material, the anti-icing material comprising a substrate in contact with each other, a self-healing resin layer, a photothermal filler layer, and a superhydrophobic filler layer.

[0080] Preferably, the anti-icing material is prepared by means of an anti-icing coating as described in the second aspect.

[0081] Fourthly, the present invention provides a method for preparing the anti-icing material as described in the third aspect, the method comprising the following steps:

[0082] The self-healing coating as described in the first aspect is applied to the substrate to obtain a self-healing resin layer;

[0083] Apply agent B, cure, and obtain a photothermal filler layer;

[0084] After softening the self-healing resin layer, agent C (which includes superhydrophobic fillers) is coated to obtain the anti-icing material.

[0085] Preferably, the curing is carried out under ultraviolet irradiation.

[0086] Preferably, the curing time is 15s-5min, such as 30s, 45s, 1min, 2min, 3min or 4min.

[0087] Preferably, the softening treatment temperature is 90-150℃, such as 100℃, 110℃, 120℃, 125℃, 130℃, 135℃, 140℃ or 145℃, and more preferably 100-130℃.

[0088] Preferably, the softening treatment time is 1-5 minutes, such as 1.5 minutes, 2 minutes, 3 minutes, 4 minutes or 4.5 minutes.

[0089] By adjusting the temperature and time of the softening treatment, the superhydrophobic filler is prevented from sinking into the resin layer due to excessive fluidity of the self-healing resin layer, thus losing its superhydrophobic and anti-icing properties. At the same time, it can obtain long-lasting superhydrophobic and anti-icing properties. With simple heating and softening and spraying, the area that has lost its superhydrophobic and anti-icing properties can be restored to its original properties.

[0090] Compared with the prior art, the present invention has at least the following beneficial effects:

[0091] The self-healing coating provided by this invention includes a DA resin with a specific structure, a mercapto curing agent, and a photo-alkali generator. The double bonds in the DA resin and the mercapto groups in the mercapto curing agent can undergo a curing reaction under the catalysis of the photo-alkali generator to form a self-healing coating. Compared with traditional self-healing coatings, this self-healing coating can be repeatedly repaired.

[0092] This invention selects DA resin as the material for a self-healing coating. When the coating is damaged, heating it above its thermosensitive point or exposing it to sunlight causes furfuryl alcohol to detach from the maleimide ring, breaking the cross-linking system, softening and leveling the coating, and automatically repairing the damaged area. Because it utilizes thiol groups and double bonds for cross-linking, it exhibits high strength at room temperature. Simultaneously, reaching the repair rheological point allows for the simple addition of hydrophobic anti-icing materials, resulting in a greater number of repair cycles compared to conventional self-healing materials. Attached Figure Description

[0093] Figure 1 This is a chemical structure diagram of the DA resin described in this invention.

[0094] Figure 2 This is the infrared spectrum from the start of the reaction to the start of end-capping in Example 1 of the present invention when DA resin was prepared.

[0095] Figure 3 This is an infrared spectrum of the DA resin from the start of end-capping preparation in Example 1 of the present invention to the curing of the self-healing resin layer during coating.

[0096] Figure 4 The figures show the photothermal performance test results of Examples 1-3 and Comparative Examples 3 and 6 of this invention.

[0097] Figure 5 (A) and (B) are infrared spectra of the DA monomer prepared in Preparation Example 2 of the present invention.

[0098] Figure 6 (A) and (B) are infrared spectra of the superhydrophobic carbon nanotubes prepared in Example 4 of the present invention.

[0099] Figure 7 The DSC rheograms are for Example 2 and Comparative Example 6.

[0100] Figure 8 The TG thermogravimetric curves are for Example 2 and Comparative Example 6.

[0101] Figure 9 The image shows the self-healing effect of the anti-icing material in Comparative Example 6 at 120°C.

[0102] Figure 10 This is a diagram showing the self-healing properties of the anti-icing material in Example 2 at 120°C. Detailed Implementation

[0103] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0104] Preparation Example 1

[0105] Preparation of photoalkali generator:

[0106] First, 10.00 mL of 10% hydrochloric acid solution was added to a single-necked flask. Then, 0.0036 mol (0.5 g) of 1,5,7-triazabicyclo[4.4.0]decen-5-ene (TBD) was weighed and added, and stirred thoroughly to dissolve. Next, 0.0040 mol (1.352 g) of sodium tetraphenylborate was added to 10.00 mL of deionized water and dissolved completely before being added to the hydrochloric acid solution. After stirring the mixture for 10.00 min, it was filtered, and the resulting precipitate was washed multiple times with water and methanol. Finally, it was recrystallized with methanol. The crystallized product was placed in a vacuum drying oven at 40 °C for 24 h to obtain 0.853 g of a photo-alkali generator (TBDHBPh4), which was then removed and stored in a dark place for later use.

[0107] Preparation Example 2

[0108] Preparation of DA monomers:

[0109] Furfuryl alcohol was purified by vacuum distillation and then placed in a refrigerator. 3 g (0.0084 mol) of biphenyl bismaleimide (BMI) was dissolved in 20 mL of chloroform and added to a single-necked flask equipped with a stir bar under nitrogen protection. The mixture was heated to 60 °C. 1.724 g (0.0176 mol) of furfuryl alcohol (FA) was dissolved in 20 mL of chloroform to obtain a furfuryl alcohol solution. The furfuryl alcohol solution was added dropwise to the single-necked flask over 30 minutes. After reacting for 24 hours, the reaction was stopped. The product was added to ethyl acetate and rapidly stirred for purification. The product was then placed in a light-proof fume hood to evaporate the solvent for 6 hours, and dried in a vacuum oven at 60 °C for 24 hours. The dried product was then ground into powder to obtain the DA monomer. Figure 5 To obtain the infrared spectrum of the DA monomer obtained in Example 2, the DA monomer was measured at 1188 cm⁻¹. -1and 1774cm -1 The characteristic peak at the point proves the successful synthesis of the DA monomer.

[0110]

[0111] Preparation Example 3

[0112] Preparation of superhydrophobic silica solution:

[0113] Dissolve 0.2g of superhydrophobic nano silica in 5g of petroleum ether, and place it in an ultrasonic machine for 5 minutes to fully dissolve and disperse it, thus obtaining a superhydrophobic silica solution.

[0114] Preparation Example 4

[0115] Preparation of superhydrophobic carbon nanotube solutions

[0116] 0.2 g of carboxylated carbon nanotubes were poured into a beaker containing 50 mL of anhydrous ethanol, 6 mL of ammonia water and 6 mL of tetraethyl orthosilicate were added, and the mixture was magnetically stirred at 900 rpm for 10 h. Then, 0.2 g of hexadecanetrimethylsilane was added, and the mixture was magnetically stirred at 900 rpm for 10 h. After the reaction was complete, the mixture was removed, filtered, and dried in an oven at 60 °C for 2 h. The dried mixture was then ground into powder. 0.2 g of the powder was poured into a beaker containing 5 g of petroleum ether, stirred, and sonicated in an ultrasonic machine for 5 min to obtain a superhydrophobic carbon nanotube solution. Figure 6 The presence of Si-O characteristic peaks and the disappearance of OH characteristic peaks in the infrared spectrum of CNTs@SiO2 proves that the superhydrophobic carbon nanotubes were successfully synthesized.

[0117] Example 1

[0118] This embodiment provides a self-healing coating comprising DA resin, trimethylolpropane tris(3-mercaptopropionate), a photoalkali generator (from Preparation Example 1), a photosensitizer (2-isopropylthioxanthanone), and a free radical inhibitor (2,2,6,6-tetramethylpiperidine-N-oxygen radical, TEMPO);

[0119] The preparation method of the self-healing coating includes:

[0120] (1) Preparation of DA resin

[0121] First, in a three-necked flask equipped with a condenser, thermometer, and mechanical stirrer, add 0.9 g (0.0009 mol) of polycaprolactone diol (PCL1000) (purchased from Maclean Biochemical Technology Co., Ltd., brand name P750206), 50 μL of dibutyltin dilaurate catalyst (DBTDL), and 50 mL of acetone. Heat to 55 °C. After the polyester diol dissolves, weigh out 0.4223 g (0.0019 mol) of isofluorodione diisocyanate (IPDI) and add it dropwise over 30 minutes with high-speed stirring (1500 r / min). React at 55 °C for 4 hours.

[0122] Add 1 g (0.0018 mol) of DA monomer and 50 μL of dibutyltin dilaurate (DBTDL) catalyst, and react at 55 °C for another 4 h.

[0123] 0.4001 g (0.0018 mol) of IPDI was added dropwise over 35 min with high-speed stirring (1500 r / min). Then, 50 μL of the catalyst dibutyltin dilaurate (DBTDL) was added dropwise, and the reaction was carried out at 55 °C for another 4 h.

[0124] Finally, add 0.0019 mol of end-capping agent hydroxypropyl acrylate (HPA), 50 μL of catalyst dibutyltin dilaurate (DBTDL), and an appropriate amount of acetone. After the reaction is complete, stop the reaction, dry the solvent, and pour out to obtain DA resin.

[0125] (2) Preparation of self-healing coatings

[0126] Take 2.96g of the DA resin obtained in step (1), 0.25g of trimethylolpropane tris(3-mercaptopropionate), 0.014g of 2-isopropylthioxanthone (ITX), 0.014g of 2,2,6,6-tetramethylpiperidine-N-oxygen radical (TEMPO), and 0.029g of photoalkali generator (TBD HBPh4). Stir and mix, add acetone to make the solid content 50%, and place in an ultrasonic machine for 30 minutes to fully mix and dissolve the substances to obtain the self-healing coating.

[0127] This embodiment also provides an anti-icing coating, comprising Agent A (self-healing coating), Agent B (from the superhydrophobic carbon nanotube solution of Preparation Example 4), and Agent C (from the superhydrophobic silica solution of Preparation Example 3).

[0128] This embodiment also provides an anti-icing material, the preparation method of which is as follows:

[0129] (1) Apply self-healing resin layer

[0130] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm scraper to apply the self-healing coating evenly to cover the substrate. After application, place the slide in a fume hood and allow it to air dry for 4 hours to obtain a self-healing resin layer.

[0131] (2) Coating with photothermal filler

[0132] Then, the superhydrophobic carbon nanotube solution was sprayed onto the resin substrate at a distance of 25cm and an angle of 45° using a spray gun. The spraying was even to coat the substrate with filler. After the solvent evaporated, the substrate was cured by irradiation with a UV lamp for 5 minutes to obtain a photothermal filler layer.

[0133] (3) Preparation of anti-icing materials

[0134] The previously obtained self-healing resin layer was softened at a temperature of 130℃ for 3 minutes. After reaching the softening point, a superhydrophobic silica solution was sprayed onto the photothermal filler layer at a distance of 25cm and an angle of 45°. The uniform spraying ensured that the filler covered the substrate, and finally, the anti-icing material was obtained.

[0135] Figure 2 This is the infrared spectrum from the start of the reaction to the start of end-capping in this embodiment of DA resin preparation. Figure 3 This is the infrared spectrum of the DA resin from the start of its end-capping process to the curing of the self-healing resin layer during the coating process in this embodiment. Figure 2 It can be seen that as the reaction proceeds, the number of isocyanate groups first decreases and then increases, proving that the reaction for synthesizing DA resin proceeds in steps. From Figure 3 It can be seen that the number of isocyanate groups gradually decreases during end-capping, proving that the end-capping reaction occurs. During compounding and curing, the number of thiol groups first increases and then decreases, proving that the reaction between the double bond and the thiol group gradually occurs.

[0136] Example 2

[0137] This embodiment provides an anti-icing material, which differs from Embodiment 1 only in that the step (2) of preparing the anti-icing material is omitted and the superhydrophobic carbon nanotube solution is not sprayed.

[0138] Specifically, the method for preparing the anti-icing material is as follows:

[0139] (1) Apply self-healing resin layer

[0140] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm scraper to apply the self-healing coating evenly to cover the substrate. After application, place the slide in a fume hood to air dry for 4 hours to obtain a self-healing resin layer. Then, irradiate it with a UV lamp for 5 minutes to cure it.

[0141] (2) Preparation of anti-icing materials

[0142] The previously obtained self-healing resin layer was softened at a temperature of 130℃ for 3 minutes. After reaching the softening point, a superhydrophobic silica solution was sprayed onto the photothermal filler layer at a distance of 25cm and an angle of 45°. The uniform spraying ensured that the filler covered the substrate, and finally, the anti-icing material was obtained.

[0143] The remaining steps are the same as in Example 1.

[0144] Example 3

[0145] This embodiment provides an anti-icing material, which differs from Embodiment 1 only in that step (3) is omitted and the superhydrophobic silica solution is not sprayed.

[0146] Specifically, the method for preparing the anti-icing material is as follows:

[0147] (1) Apply self-healing resin layer

[0148] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm scraper to apply the self-healing coating evenly to cover the substrate. After application, place the slide in a fume hood and allow it to air dry for 4 hours to obtain a self-healing resin layer.

[0149] (2) Coating with photothermal filler

[0150] Then, the superhydrophobic carbon nanotube solution was sprayed onto the resin substrate at a distance of 25cm and an angle of 45° using a spray gun. The coating was evenly applied to ensure that the filler covered the substrate. After the solvent evaporated, the substrate was irradiated with an ultraviolet lamp for 5 minutes to cure it, thus obtaining the anti-icing material.

[0151] The remaining steps are the same as in Example 1.

[0152] Example 4

[0153] This embodiment provides a self-healing coating comprising DA resin, trimethylolpropane tris(3-mercaptopropionate), a photoalkali generator (from Preparation Example 1), a photosensitizer (2-isopropylthioxanthanone), and a free radical inhibitor (2,2,6,6-tetramethylpiperidine-N-oxygen radical, TEMPO);

[0154] The only difference between this example and Example 1 is that the preparation method of the self-healing coating includes:

[0155] (1) Preparation of DA resin

[0156] First, in a three-necked flask equipped with a condenser, thermometer, and mechanical stirrer, add 0.9 g (0.0009 mol) of polycaprolactone diol (PCL1000), 50 μL of dibutyltin dilaurate catalyst (DBTDL), and 50 mL of acetone. Heat to 55°C. After the polyester diol dissolves, weigh out 0.3001 g (0.0014 mol) of isofluorodione diisocyanate (IPDI) and add it dropwise over 30 minutes with high-speed stirring (1000 r / min). React at 40°C for 3 hours. Then add 0.7486 g (0.0014 mol) of DA monomer and 50 μL of dibutyltin dilaurate catalyst (DBTDL), and react at 40°C for another 3 hours.

[0157] 0.3001 g (0.0014 mol) of IPDI was added dropwise over 35 min with high-speed stirring (1000 r / min), followed by the addition of 50 μL of the catalyst dibutyltin dilaurate (DBTDL). The reaction was then carried out at 40 °C for 3 h.

[0158] Finally, add 0.0014 mol of end-capping agent hydroxypropyl acrylate (HPA), 50 μL of catalyst dibutyltin dilaurate (DBTDL), and an appropriate amount of acetone. After the reaction is complete, stop the reaction, dry the solvent, and pour out to obtain DA resin.

[0159] (2) Preparation of self-healing coating

[0160] Take 2.42g of DA resin obtained in step (1), 0.48g of trimethylolpropane tris(3-mercaptopropionate), 0.016g of 2-isopropylthioxanthone (ITX), 0.014g of 2,2,6,6-tetramethylpiperidine-N-oxygen radical (TEMPO), and 0.048g of photoalkali generator (TBD HBPh4), stir and mix them together, add acetone to make its solid content 50%, and place it in an ultrasonic machine for 30 minutes to sonicate and dissolve the substances to obtain the self-healing coating.

[0161] This embodiment also provides an anti-icing coating and the anti-icing material formed therefrom, the preparation method of which is as follows:

[0162] (1) Apply self-healing resin layer

[0163] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm scraper to apply the self-healing coating evenly to cover the substrate. After application, place the slide in a fume hood and allow it to air dry for 4 hours to obtain a self-healing resin layer.

[0164] (2) Coating with photothermal filler

[0165] Then, the obtained superhydrophobic carbon nanotube solution was sprayed onto the resin substrate at a distance of 25cm and an angle of 45° using a spray gun. The filler was evenly sprayed to cover the substrate. After the solvent evaporated, it was irradiated with a UV lamp for 5 minutes to cure it, thus obtaining a photothermal filler layer.

[0166] (3) Preparation of anti-icing materials

[0167] The previously obtained self-healing resin layer was softened at 100℃ for 1 minute. After reaching the softening point, a superhydrophobic silica solution was sprayed onto the photothermal filler layer at a distance of 25cm and an angle of 45°. The spraying was uniform to ensure the filler covered the substrate, thus obtaining the anti-icing material.

[0168] Example 5

[0169] This embodiment provides a self-healing coating comprising DA resin, trimethylolpropane tris(3-mercaptopropionate), a photoalkali generator (from Preparation Example 1), a photosensitizer (2-isopropylthioxanthanone), and a free radical inhibitor (2,2,6,6-tetramethylpiperidine-N-oxy radical, TEMPO);

[0170] The only difference between this example and Example 1 is that the preparation method of the self-healing coating includes:

[0171] (1) Preparation of DA resin

[0172] First, in a three-necked flask equipped with a condenser, thermometer, and mechanical stirrer, add 0.9 g (0.0009 mol) of polycaprolactone diol (PCL1000), 50 μL of dibutyltin dilaurate catalyst (DBTDL), and 50 mL of acetone. Heat to 55°C. After the polyester diol dissolves, weigh out 0.4890 g (0.0022 mol) of isofluorodione diisocyanate (IPDI) and add it dropwise over 30 minutes with high-speed stirring (2000 rpm). React at 60°C for 5 hours. Then add 1.2200 g (0.0022 mol) of DA monomer and 50 μL of dibutyltin dilaurate catalyst (DBTDL), and react at 60°C for another 5 hours.

[0173] 0.4890 g (0.0022 mol) of IPDI was added dropwise over 35 min with high-speed stirring (2000 r / min). Then, 50 μL of the catalyst dibutyltin dilaurate (DBTDL) was added dropwise, and the reaction was carried out at 60 °C for another 5 h.

[0174] Finally, add 0.0022 mol of end-capping agent hydroxypropyl acrylate (HPA), 50 μL of catalyst dibutyltin dilaurate (DBTDL), and an appropriate amount of acetone. After the reaction is complete, stop the reaction, dry the solvent, and pour it out to obtain DA resin.

[0175] (2) Preparation of self-healing coating

[0176] Take 3.35g of DA resin obtained in step (1), 0.23g of trimethylolpropane tris(3-mercaptopropionate), 0.014g of 2-isopropylthioxanthone (ITX), 0.014g of 2,2,6,6-tetramethylpiperidine-N-oxygen radical (TEMPO), and 0.023g of photoalkali generator (TBD HBPh4) and stir to mix. Add acetone to make its solid content 50%. Place it in an ultrasonic machine and sonicate for 30 minutes to fully mix and dissolve the substances to obtain the self-healing coating.

[0177] This embodiment also provides an anti-icing coating and the anti-icing material formed therefrom, the preparation method of which is as follows:

[0178] (1) Apply self-healing resin layer

[0179] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm scraper to apply the self-healing coating evenly to cover the substrate. After application, place the slide in a fume hood and allow it to air dry for 4 hours to obtain a self-healing resin layer.

[0180] (2) Coating with photothermal filler

[0181] Then, the obtained superhydrophobic carbon nanotube solution was sprayed onto the resin substrate at a distance of 25cm and an angle of 45° using a spray gun. The filler was evenly sprayed to cover the substrate. After the solvent evaporated, it was irradiated with a UV lamp for 5 minutes to cure it, thus obtaining a photothermal filler layer.

[0182] (3) Preparation of anti-icing materials

[0183] The previously obtained self-healing resin layer was softened at a temperature of 120℃ for 5 minutes. After reaching the softening point, a superhydrophobic silica solution was sprayed onto the photothermal filler layer at a distance of 25cm and an angle of 45°. The spraying was uniform to ensure that the filler covered the substrate, thus obtaining the anti-icing material.

[0184] Comparative Example 1

[0185] This comparative example provides an anti-icing material, which differs from Example 1 only in that trimethylolpropane tris(3-mercaptopropionate) and photoalkali generator (TBD HBPh4) are not added when preparing the self-healing coating.

[0186] Comparative Example 2

[0187] This comparative example provides an anti-icing material, which differs from Example 1 only in that, when preparing the DA resin, the DA monomer is replaced with an equimolar amount of polyethylene glycol 500 (purchased from MCE).

[0188] Comparative Example 3

[0189] Comparative Example 3 is a bare glass slide without any coating.

[0190] Comparative Example 4

[0191] This comparative example provides an anti-icing material, which differs from Example 1 only in that, during the preparation of DA resin, dibutyltin dilaurate (DBTDL) is replaced with an equimolar amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0192] Comparative Example 5

[0193] This comparative example provides an anti-icing material, which differs from Example 1 only in that the synthesis steps of the DA resin are as follows:

[0194] First, in a three-necked flask equipped with a condenser, thermometer, and mechanical stirrer, add 0.9 g (0.0009 mol) of polycaprolactone diol (PCL1000), 50 μL of dibutyltin dilaurate catalyst (DBTDL), and 50 mL of acetone. Heat to 55 °C. After the polyester diol dissolves, weigh out 0.8224 g (0.0037 mol) of isofluorodiketone diisocyanate (IPDI) and add it dropwise over 30 minutes with high-speed stirring (1500 rpm). React at 55 °C for 4 hours.

[0195] Add 1 g (0.0018 mol) of DA monomer and 50 μL of dibutyltin dilaurate (DBTDL) catalyst, and react at 55 °C for another 4 h.

[0196] Add 50 μL of the catalyst dibutyltin dilaurate (DBTDL) dropwise, and react at 55 °C for another 4 h.

[0197] Finally, add 0.0019 mol of end-capping agent hydroxypropyl acrylate (HPA), 50 μL of catalyst dibutyltin dilaurate (DBTDL), and an appropriate amount of acetone. After the reaction is complete, stop the reaction, dry the solvent, and pour out to obtain DA resin.

[0198] Comparative Example 6

[0199] This comparative example provides an anti-icing material, which differs from Example 1 only in that, when coating the self-healing resin layer, a superhydrophobic carbon nanotube solution is not sprayed; and when preparing the anti-icing material, a superhydrophobic silica solution is not sprayed.

[0200] Specifically, the method for preparing the anti-icing material is as follows:

[0201] Cut a 2cm x 2cm glass slide, rinse it with alcohol, and wipe it dry with degreased cotton. Use a 500μm applicator to apply the self-healing coating evenly to cover the substrate. After application, place it in a fume hood to air dry for 4 hours to obtain a self-healing resin layer. Irradiate with a UV lamp for 5 minutes to cure, obtaining the anti-icing material.

[0202] The remaining steps are the same as in Example 1.

[0203] Test methods

[0204] Infrared characterization: The corresponding samples are characterized by infrared radiation.

[0205] Photothermal performance test: At room temperature (22℃), the irradiation power of the near-infrared laser was set to 1W, the center distance between the near-infrared laser probe and the coating surface was controlled to 10cm, and the diameter of the infrared aperture was set to 5mm. The timer started from turning on the infrared laser, irradiated for 300s, and cooled for 300s to test the photothermal performance of the material.

[0206] Freezing Time Test: The process by which a water droplet completely solidifies from a hemispherical shape into an ice crystal with a pointed tip is called complete freezing. Four states are defined here: coating edge freezing point, pre-freezing state, frozen state, and fully frozen state, each corresponding to a different freezing morphology. Specifically, coating edge freezing refers to freezing occurring at the interface between the coating and the water droplet; pre-freezing refers to the initial formation of ice crystals within the water droplet; frozen state refers to the state where ice crystals occupy the entire volume of the water droplet; and fully frozen state refers to the state where no liquid water remains inside the water droplet, and the ice crystal structure is intact.

[0207] De-icing time test: Under a completely frozen environment (-10℃), ice crystals on each coating were irradiated with a near-infrared laser, and the morphological changes of the ice crystals were observed and the time for complete melting was recorded. De-icing performance was analyzed based on the morphological changes and melting time of the ice crystals. Two freezing state points were defined here: the ice crystal flow point and the complete melting point. Ice crystal flow refers to the state where liquid water begins to appear inside the ice crystal, and complete melting refers to the state where the ice crystal has completely transformed into liquid water.

[0208] Coating mechanical property testing: The coating hardness is tested according to GB / T 6739-1996, the coating adhesion is tested according to GB / T1720-1979, and the coating flexibility is tested according to GB / T 1731-1993.

[0209] Self-healing test: The scratch self-healing of DA-SH and DA-SH-SiO2 was characterized using an optical microscope (Mingmei Optoelectronics Technology Co., Ltd., MP41) and a heating stage. Specifically, the coating was scratched with a blade, and the scratched coating was placed on a heating stage preheated to 80°C. The stage was heated until it reached 120°C, at which point the time was started, and the repair of the scratches was observed and recorded using a microscope.

[0210] Test Results

[0211] Table 1

[0212]

[0213]

[0214] Figure 4 The photothermal performance of Examples 1-3 and Comparative Examples 3 and 6 was tested. As can be seen from the highest point of each curve in the figure, Example 1 has the highest photothermal effect temperature rise point of 156.9℃, and has the best photothermal effect. Figure 7 The test results show that after adding silica, the softening temperature of the coating decreased from 125℃ to 120℃. Figure 8 The test results show that, based on the anti-icing coating of Example 2 with a mass percentage of 100%, the mass percentage of silica is 7.9%. Figure 9 and Figure 10 Test results show that the anti-icing material of this application can self-repair within 150 seconds.

[0215] The test results in Table 1 show that:

[0216] (1) As can be seen from Examples 1 to 5, the present invention obtains a coating with high strength and good anti-icing effect by adding DA resin with a specific structure, mercapto curing agent and photoalkali generator to the self-healing coating.

[0217] (2) By comparing Example 1 with Examples 2-3, it can be seen that if superhydrophobic carbon nanotubes or superhydrophobic silica are not added, the freezing time and thawing time of the coating will be prolonged, and the maximum temperature rise of the photothermal effect will also decrease.

[0218] (3) As can be seen from the comparison between Example 1 and Comparative Example 1, the present invention improves the hardness, adhesion and toughness of the coating by adding mercapto curing agent and photoalkali generator.

[0219] (4) As can be seen from the comparison between Example 1 and Comparative Example 2, the present invention improves the repeated repair capability of the coating by adding DA monomer.

[0220] (5) As can be seen from the comparison between Example 1 and Comparative Examples 4-5, the present invention can obtain a more symmetrical DA resin by selecting a specific type of catalyst and adding IPDI step by step, thereby improving the hardness, adhesion and toughness of the coating.

[0221] In summary, by selecting DA resin as the material for the self-healing coating, this invention can obtain an anti-icing coating with self-healing effect.

[0222] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An anti-icing material, characterized in that, The anti-icing material comprises a substrate in contact with each other, a self-healing resin layer, a photothermal filler layer, and a superhydrophobic filler layer; The method for preparing the anti-icing material includes the following steps: A self-healing coating is applied to the substrate to obtain a self-healing resin layer; Apply agent B, cure, and obtain a photothermal filler layer; After softening the self-healing resin layer, agent C is coated to obtain the anti-icing material; The self-healing coating comprises DA resin, mercapto curing agent, and photoalkali generator; The DA resin has the structure shown in Formula I: Equation I; R1 is a divalent group derived from a polymeric diol; R2 is a C6-C30 divalent group containing an aromatic structure; R3 is a C1-C10 divalent group containing an ester group or a C1-C10 divalent group containing an ether bond; The DA resin is prepared by the following method, the method comprising: (1) The polymer diol and isophorone diisocyanate were reacted under the catalysis of dibutyltin dilaurate to obtain the first intermediate with isocyanate group end capping; (2) The first intermediate is reacted with DA monomer to obtain a hydroxyl-terminated second intermediate; The structural formula of the DA monomer is as follows: R2 has the same defined range as in Equation I; (3) The second intermediate reacts with isophorone diisocyanate under the catalysis of dibutyltin dilaurate to obtain a third intermediate with isocyanate group end capping; (4) The third intermediate reacts with the capping agent to obtain the DA resin; The structure of the capping agent is as follows: R3 has the same defined range as in Equation I; The molar ratio of isophorone diisocyanate to polymeric diol in step (1) is (1.5-2.5):1; The molar ratio of isophorone diisocyanate to the second intermediate in step (3) is (1.5-2.5):1; The reaction temperatures in steps (1) and (3) are each independently 40-60℃; Agent B includes a photothermal filler, and agent C includes a superhydrophobic filler.

2. The anti-icing material according to claim 1, characterized in that, R1 is selected from any of the following structures: , , or ; in, Indicates the linkage site of the functional group; n3, n4, n5, n6, n7, and n8 are each an independent integer between 5 and 35.

3. The anti-icing material according to claim 1, characterized in that, R2 is , Indicates the linking site of a functional group.

4. The anti-icing material according to claim 1, characterized in that, R3 is selected from any of the following structures: , , or , Indicates the linking site of a functional group.

5. The anti-icing material according to claim 1, characterized in that, The number-average molecular weight of the DA resin is 1000-5000 g / mol.

6. The anti-icing material according to claim 1, characterized in that, The reaction temperatures in steps (2) and (4) are each 40-60℃.

7. The anti-icing material according to claim 1, characterized in that, The reaction times described in steps (1), (2), (3), and (4) are each 3-5 h independently.

8. The anti-icing material according to claim 1, characterized in that, The reactions described in steps (1) and (3) are carried out under stirring conditions.

9. The anti-icing material according to claim 8, characterized in that, The stirring speed of the reactions described in steps (1) and (3) is 1000-2000 rpm each.

10. The anti-icing material according to claim 1, characterized in that, The molar ratio of the DA monomer to the first intermediate in step (2) is (1.5-2.5):

1.

11. The anti-icing material according to claim 1, characterized in that, The molar ratio of the capping agent to the third intermediate in step (4) is (1.5-2.5):

1.

12. The anti-icing material according to claim 1, characterized in that, The mercapto curing agent includes trimethylolpropane tris(3-mercaptopropionate).

13. The anti-icing material according to claim 1, characterized in that, The mass ratio of the DA resin to the mercapto curing agent is (5-15):

1.

14. The anti-icing material according to claim 1, characterized in that, The photoalkali generator is obtained by reacting organic bases and photoalkali-producing salts.

15. The anti-icing material according to claim 14, characterized in that, The organic base includes any one or a combination of at least two of the following: triethylamine, tributylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, or 1,5,7-trizabicyclo[4.4.0]decene-5-ene.

16. The anti-icing material according to claim 14, characterized in that, The photo-alkali-producing salt includes sodium tetraphenylborate.

17. The anti-icing material according to claim 1, characterized in that, The mass ratio of the DA resin to the photo-alkali generator is (50-150):

1.

18. The anti-icing material according to claim 1, characterized in that, The self-healing coating also includes a photosensitizer.

19. The anti-icing material according to claim 18, characterized in that, The photosensitizer includes any one or a combination of at least two of 2-isopropylthioxanthones, 4-isopropylthioxanthones, 2-chlorothioxanthones, or benzophenone.

20. The anti-icing material according to claim 18, characterized in that, The mass ratio of the DA resin to the photosensitizer is (150-250):

1.

21. The anti-icing material according to claim 1, characterized in that, The self-healing coating also includes a free radical polymerization inhibitor.

22. The anti-icing material according to claim 21, characterized in that, The mass ratio of the free radical polymerization inhibitor to the photosensitizer is 1:(0.3-3).

23. The anti-icing material according to claim 21, characterized in that, The free radical polymerization inhibitors include 2,2,6,6-tetramethylpiperidine-N-oxy radicals and / or butylated hydroxytoluene.

24. The anti-icing material according to claim 1, characterized in that, The self-healing coating also includes a solvent.

25. The anti-icing material according to claim 24, characterized in that, The solvent includes acetone.

26. The anti-icing material according to claim 1, characterized in that, The solid content of the self-healing coating is 40%-60%.

27. The anti-icing material according to claim 1, characterized in that, The photothermal filler includes superhydrophobic carbon nanotubes.

28. The anti-icing material according to claim 1, characterized in that, Agent B also includes a solvent.

29. The anti-icing material according to claim 28, characterized in that, The solvent includes petroleum ether.

30. The anti-icing material according to claim 1, characterized in that, The mass percentage of photothermal filler in Agent B is 2%-10%.

31. The anti-icing material according to claim 1, characterized in that, The superhydrophobic filler includes superhydrophobic silica.

32. The anti-icing material according to claim 1, characterized in that, The agent C also includes a solvent.

33. The anti-icing material according to claim 32, characterized in that, The solvent includes petroleum ether.

34. The anti-icing material according to claim 1, characterized in that, The superhydrophobic filler content in agent C is 2%-10% by mass.

35. A method for preparing an anti-icing material as described in any one of claims 1-34, characterized in that, The preparation method includes the following steps: A self-healing coating is applied to the substrate to obtain a self-healing resin layer; Apply agent B, cure, and obtain a photothermal filler layer; After softening the self-healing resin layer, agent C is coated to obtain the anti-icing material.

36. The method for preparing the anti-icing material according to claim 35, characterized in that, The curing process is carried out under ultraviolet irradiation.

37. The method for preparing the anti-icing material according to claim 35, characterized in that, The curing time is 15 seconds to 5 minutes.

38. The method for preparing the anti-icing material according to claim 35, characterized in that, The softening treatment temperature is 90-150℃.

39. The method for preparing the anti-icing material according to claim 35, characterized in that, The softening treatment temperature is 100-130℃.

40. The method for preparing the anti-icing material according to claim 35, characterized in that, The softening process takes 1-5 minutes.

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