A self-healing coating capable of automatically repairing micro-scratches and a preparation method thereof

Abstract

The present application provides a kind of self-healing coating capable of automatically repairing micro scratch and its preparation method.The raw materials for preparing the self-healing coating include resin and solvent, wherein, according to weight ratio, the resin: the solvent = (8-10) : 1.The self-healing coating provided by the present application can absorb and store heat to increase the temperature of the self-healing coating by adding photo-thermal filler with good heat absorption and heat fixation performance and heat absorption solvent under the irradiation of sunlight.In high temperature conditions, the polymer aggregate in the self-healing coating plays a role to repair micro scratch and achieve self-healing effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of self-healing coatings, in particular to a self-healing coating capable of automatically repairing minor scratches and a preparation method thereof. BACKGROUND

[0002] Coatings are materials coated on the surface of objects to be protected or decorated, and can form a continuous film with the coated object. The material is usually a viscous liquid prepared by adding or not adding pigments, fillers, and corresponding additives to resins, oils, and emulsions, and using organic solvents or water.

[0003] In recent years, a large number of paint film scratch-resistant coatings have appeared in the coating industry, but they are basically achieved by increasing the hardness of the paint film and enhancing the smoothness of the paint film surface. At present, there are relatively few wall coatings on the market that can resist scratches and self-heal, and the scratch resistance and self-healing performance are not ideal. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a self-healing coating capable of automatically repairing minor scratches and a preparation method thereof.

[0005] The purpose of the present application is to provide a self-healing coating capable of automatically repairing minor scratches, and the raw materials for preparing the self-healing coating include resins and solvents, wherein the resins:solvents = (8-10) : 1 by weight;

[0006] The resin includes the following components by weight: epoxy resin 20-30 parts, polyimide resin 30-50 parts, iron oxide red 2-4 parts, talc powder 20-30 parts, mica powder 15-25 parts, light and heat filler 10-20 parts, and polymer aggregate 30-50 parts.

[0007] The solvent includes the following components by weight: tetrahydrofuran 100-200 parts, azobisdimethylamide 5-10 parts, diluent 10-15 parts, polydimethylsiloxane 3-5 parts, and endothermic solvent 10-20 parts.

[0008] The self-healing coating provided by the present application improves the scratch resistance of the coating by adding talc powder and mica powder. The lubricity and flowability of talc powder help the uniform distribution of mica powder in the coating. At the same time, the hardness and toughness of mica powder can make up for the low hardness of talc powder. In addition, the layered structure of talc powder and mica powder can form a dense protective film in the coating, which helps to resist scratches and scratches from the outside and improve the scratch resistance of the coating.

[0009] Preferably, the photo-thermal filler raw material comprises ferriferrous oxide and carbon black; and the weight ratio of the ferriferrous oxide to the carbon black is (2-4):(3-5).

[0010] The self-healing coating provided by the present application improves the heat absorption and heat fixation performance of the coating by adding photo-thermal fillers. The photo-thermal fillers are prepared by combining ferriferrous oxide and carbon black, both of which have a certain light absorption capacity and can convert light energy into heat energy. Through photo-thermal conversion, this combination can effectively improve the temperature of the coating, thereby achieving temperature regulation.

[0011] Preferably, the polymer aggregate raw material comprises dopamine methacrylamide and methacryloxypropyl dimethyl methoxy silane; and the weight ratio of the dopamine methacrylamide to the methacryloxypropyl dimethyl methoxy silane is 1:(2-4).

[0012] The self-healing coating provided by the present application adds polymer aggregates prepared from dopamine methacrylamide and methacryloxypropyl dimethyl methoxy silane to achieve repair of minor scratches and achieve self-healing effect. The photo-thermal fillers and heat-absorbing solvents added to the self-healing coating have good heat absorption and heat fixation performance, so that the self-healing coating can absorb and store heat under the irradiation of sunlight to increase the temperature of the coating. Dopamine methacrylamide and methacryloxypropyl dimethyl methoxy silane can undergo free radical polymerization at high temperatures to generate graft copolymers. This copolymer has autonomous self-repairing ability and is an intrinsic self-repairing material. Among them, methacryloxypropyl dimethyl methoxy silane acts as a flexible segment, which can increase the movement ability of dopamine methacrylamide, and the hydrogen bonds in dopamine methacrylamide are the key to self-repairing. When the coating is damaged by minor scratches, these hydrogen bonds can be reformed to repair the scratches.

[0013] Preferably, the diluent raw material comprises allyl glycidyl ether and polyester modified acrylate; and the weight ratio of the allyl glycidyl ether to the polyester modified acrylate is (1-3):(2-4).

[0014] Preferably, the heat-absorbing solvent raw material comprises ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution; and the weight ratio of the ammonium nitrate solution, the ammonium chloride solution and the potassium nitrate solution is (3-6):(1-3):(2-4).

[0015] The self-healing coating provided by the present application improves the heat absorption performance of the coating by adding heat-absorbing solvents. The heat-absorbing solvents are prepared from ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution, all of which have good heat absorption performance. The combination of the three solvents produces a superposition effect on the heat absorption performance, which can absorb more heat. When applied to the preparation process of the coating, the heat absorption performance of the coating is improved.

[0016] Another object of the present application is to provide a preparation method of a self-healing paint capable of automatically repairing micro scratches, comprising the following steps:

[0017] S1, mix the epoxy resin, the polyimide resin, heat and stir, cool to room temperature, add the talc powder, the mica powder, the red iron oxide, the light-heat filler and the polymer aggregate, stir uniformly, grind, and obtain a resin;

[0018] S2, mix the tetrahydrofuran, the azobisisobutyronitrile and the polydimethylsiloxane, heat and stir uniformly, cool to room temperature, add the diluent, the endothermic solvent and vacuum stir to obtain a mixture A;

[0019] S3, mix the resin of step S1 and the mixture A of step S2, stir uniformly, and obtain a self-healing paint.

[0020] Preferably, the heating temperature in step S1 is 900-1200℃, and the heating time is 2-3h.

[0021] Preferably, the heating temperature in step S2 is 1500-2000℃, and the heating time is 3-5h. DETAILED DESCRIPTION

[0022] The technical features in the technical solutions provided by the present application will be further described clearly and completely in combination with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] Embodiment 1

[0024] The present embodiment provides a self-healing paint capable of automatically repairing micro scratches, which is prepared by the following steps:

[0025] 1. Raw material preparation:

[0026] Resin: epoxy resin 20 parts, polyimide resin 30 parts, red iron oxide 2 parts, talc powder 20 parts, mica powder 15 parts, light-heat filler 10 parts, polymer aggregate 30 parts;

[0027] Solvent: tetrahydrofuran 100 parts, azobisisobutyronitrile 5 parts, diluent 10 parts, polydimethylsiloxane 3 parts, endothermic solvent 10 parts.

[0028] 2. Preparation of self-healing paint:

[0029] S1, the epoxy resin, the polyimide resin is mixed, heating stirring, cooling to room temperature, add the talcum powder, the mica powder, the iron oxide red, the light heat filler and the polymer aggregate, stirring, grinding, get resin;

[0030] S2, the tetrahydrofuran, the azobisdimethyl isobutyronitrile and the polydimethylsiloxane are mixed, heated and stirred uniformly, cooled to room temperature, add the diluent, the endothermic solvent vacuum stirring, get mixture A;

[0031] S3, the resin of step S1 and the mixture A of step S2 are mixed, stirred uniformly, get self-healing coating.

[0032] Wherein, the weight ratio of resin to solvent is 8:1.

[0033] Wherein, the light heat filler is prepared from ferriferrous oxide, carbon black, and the weight ratio of ferriferrous oxide microbody to carbon black is 2:3.

[0034] Wherein, the polymer aggregate is prepared from dopamine methacrylamide and methacryloyloxypropyl dimethyl methoxysilane, and the weight ratio of dopamine methacrylamide to methacryloyloxypropyl dimethyl methoxysilane is 1:2.

[0035] Wherein, the diluent is prepared from allyl glycidyl ether and polyester modified acrylate, and the weight ratio of allyl glycidyl ether to polyester modified acrylate is 1:2.

[0036] Wherein, the endothermic solvent is composed of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution, and the weight ratio of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution is 3:1:2.

[0037] Wherein, the heating temperature of step S1 is 900℃, and the heating time is 2h.

[0038] Wherein, the heating temperature of step S2 is 1500℃, and the heating time is 3h.

[0039] Example 2

[0040] The present embodiment provides a self-healing coating capable of automatically repairing micro scratches, which is prepared by the following steps:

[0041] 1, raw material preparation:

[0042] Resin: epoxy resin 25 parts, polyimide resin 40 parts, iron oxide red 3 parts, talcum powder 25 parts, mica powder 20 parts, light heat filler 15 parts, polymer aggregate 40 parts;

[0043] Solvent: tetrahydrofuran 150 parts, azobisisobutyronitrile 7 parts, diluent 13 parts, polydimethylsiloxane 4 parts, endothermic solvent 15 parts.

[0044] 2. Self-healing coating preparation:

[0045] S1, the epoxy resin, the polyimide resin is mixed, heated and stirred, cooled to room temperature, the talc, the mica powder, the iron oxide red, the light heat filler and the polymer aggregate are added, stirred uniformly, ground, and the resin is obtained;

[0046] S2, the tetrahydrofuran, the azobisisobutyronitrile and the polydimethylsiloxane are mixed, heated and stirred uniformly, cooled to room temperature, the diluent, the endothermic solvent is added, and the mixture A is obtained by vacuum stirring;

[0047] S3, the resin of step S1 and the mixture A of step S2 are mixed, stirred uniformly, and the self-healing coating is obtained.

[0048] Wherein, the weight ratio of resin to solvent is 9:1.

[0049] Wherein, the light heat filler is prepared from ferroferric oxide micro and carbon black, and the weight ratio of ferroferric oxide micro to carbon black is 3:4.

[0050] Wherein, the polymer aggregate is prepared from dopamine methacrylamide and methacryloyloxypropyl dimethyl methoxysilane, and the weight ratio of dopamine methacrylamide to methacryloyloxypropyl dimethyl methoxysilane is 1:3.

[0051] Wherein, the diluent is prepared from allyl glycidyl ether and polyester modified acrylate, and the weight ratio of allyl glycidyl ether to polyester modified acrylate is 2:3.

[0052] Wherein, the endothermic solvent is composed of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution, and the weight ratio of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution is 5:2:3.

[0053] Wherein, the heating temperature of step S1 is 1050℃, and the heating time is 2.5h.

[0054] Wherein, the heating temperature of step S2 is 1750℃, and the heating time is 4h.

[0055] Example 3

[0056] The present embodiment provides a self-healing coating capable of automatically repairing micro scratches, which is prepared by the following steps:

[0057] 1. Raw material preparation:

[0058] Resin: epoxy resin 30 parts, polyimide resin 50 parts, iron oxide red 4 parts, talc powder 30 parts, mica powder 25 parts, light-heat filler 20 parts, polymer aggregate 50 parts;

[0059] Solvent: tetrahydrofuran 200 parts, azobisdimethyl isobutyronitrile 10 parts, diluent 15 parts, polydimethylsiloxane 5 parts, endothermic solvent 20 parts.

[0060] 2. Self-healing coating preparation:

[0061] S1, the epoxy resin, the polyimide resin is mixed, heated and stirred, cooled to room temperature, the talc powder, the mica powder, the iron oxide red, the light-heat filler and the polymer aggregate are added, stirred uniformly, ground, and the resin is obtained;

[0062] S2, the tetrahydrofuran, the azobisdimethyl isobutyronitrile and the polydimethylsiloxane are mixed, heated and stirred uniformly, cooled to room temperature, the diluent, the endothermic solvent is added, and the mixture A is obtained by vacuum stirring;

[0063] S3, the resin of step S1 and the mixture A of step S2 are mixed, stirred uniformly, and the self-healing coating is obtained.

[0064] Among them, the weight ratio of resin to solvent is 10:1.

[0065] Among them, the light-heat filler is prepared from ferroferric oxide micro and carbon black, and the weight ratio of ferroferric oxide micro to carbon black is 4:5.

[0066] Among them, the polymer aggregate is prepared from dopamine methacrylamide and methacryloxypropyl dimethyl methoxy silane, and the weight ratio of dopamine methacrylamide to methacryloxypropyl dimethyl methoxy silane is 1:4.

[0067] Among them, the diluent is prepared from allyl glycidyl ether and polyester modified acrylate, and the weight ratio of allyl glycidyl ether to polyester modified acrylate is 3:4.

[0068] Among them, the endothermic solvent is composed of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution, and the weight ratio of ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution is 6:3:4.

[0069] Among them, the heating temperature of step S1 is 1200℃, and the heating time is 3h.

[0070] Among them, the heating temperature of step S2 is 2000℃, and the heating time is 2h.

[0071] Example 4

[0072] The embodiment provides a self-healing coating capable of automatically repairing micro scratches, and the difference from the embodiment 1 is that the photo-thermal filler is prepared from only the ferriferrous oxide. Except the above difference, the materials, the formula ratio and the preparation operation adopted in the embodiment are strictly consistent with those in the embodiment 1.

[0073] Embodiment 5

[0074] The embodiment provides a self-healing coating capable of automatically repairing micro scratches, and the difference from the embodiment 1 is that the endothermic solvent is prepared from only the ammonium nitrate solution. Except the above difference, the materials, the formula ratio and the preparation operation adopted in the embodiment are strictly consistent with those in the embodiment 1.

[0075] Embodiment 6

[0076] The embodiment provides a self-healing coating capable of automatically repairing micro scratches, and the difference from the embodiment 1 is that the polymer aggregate is prepared from only the dopamine methacrylamide. Except the above difference, the materials, the formula ratio and the preparation operation adopted in the embodiment are strictly consistent with those in the embodiment 1.

[0077] Embodiment 7

[0078] The embodiment provides a self-healing coating capable of automatically repairing micro scratches, and the difference from the embodiment 1 is that the diluent is prepared from only the allyl glycidyl ether. Except the above difference, the materials, the formula ratio and the preparation operation adopted in the embodiment are strictly consistent with those in the embodiment 1.

[0079] Test example

[0080] The self-healing coatings prepared in the embodiments 1-7 are selected to perform coating tests, and the wall outer facade is selected as a coating surface, the test is performed outdoors, and after the coating is completely dried, a coin is used to scratch the surface for 1 min, the coating surface should be ventilated, the distance between three coatings should be 1.2-1.5 m, and the test temperature should be normal outdoor temperature, and the final test results are shown in the following table 1.

[0081] Table 1 Test results of the self-healing coating

[0082]

[0083]

[0084] The self-healing coatings of Example 1, Example 2 and Example 3 all showed good scratch repair performance within 72 hours after painting and scratching, and the scratches were basically disappeared. This shows that the ratio and interaction between the components in these coatings, such as resins, solvents, photo-thermal fillers, polymer aggregates, etc., are effective, and can realize the function of automatically repairing small scratches. The self-healing coatings of Example 4, Example 5, Example 6 and Example 7 did not have as good scratch repair effect as Example 1, 2, 3 within 72 hours after painting and scratching, and the scratches were only slightly faded. This may be due to the changes in the formulations of these coatings, such as the changes in the types and proportions of photo-thermal fillers, heat-absorbing solvents or polymer aggregates, which affect the self-healing performance of the coatings. The common exterior facade coatings on the market still have obvious scratches within 72 hours after painting and scratching, and do not show any self-healing performance.

[0085] The above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the above examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents, and these modifications or replacements are within the protection scope of the present application.

Claims

1. A self-healing coating capable of automatically repairing minor scratches, characterized in that, The raw materials for preparing the self-healing coating include resin and solvent, wherein, by weight ratio, the resin:solvent = (8-10):1; The resin comprises the following components in parts by weight: 20-30 parts epoxy resin, 30-50 parts polyimide resin, 2-4 parts iron oxide red, 20-30 parts talc powder, 15-25 parts mica powder, 10-20 parts photothermal filler, and 30-50 parts polymer aggregate. The solvent comprises the following components in parts by weight: 100-200 parts tetrahydrofuran, 5-10 parts azobisisobutyronitrile, 10-15 parts diluent, 3-5 parts polydimethylsiloxane, and 10-20 parts endothermic solvent. The photothermal filler material includes iron oxide and carbon black; and the weight ratio of iron oxide to carbon black is (2-4):(3-5); The polymer aggregate raw materials include dopamine methacrylamide and methacryloyloxypropyl dimethylmethoxysilane; and the weight ratio of dopamine methacrylamide to methacryloyloxypropyl dimethylmethoxysilane is 1:(2-4); The diluent raw materials include allyl glycidyl ether and polyester-modified acrylate; and the weight ratio of allyl glycidyl ether to polyester-modified acrylate is (1-3):(2-4). The endothermic solvent raw materials include ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution; and the weight ratio of the ammonium nitrate solution, ammonium chloride solution and potassium nitrate solution is (3-6):(1-3):(2-4).

2. A method for preparing the self-healing coating as described in claim 1, characterized in that, Includes the following steps: S1. Mix the epoxy resin and the polyimide resin, heat and stir, cool to room temperature, add the talc powder, the mica powder, the iron oxide red, the photothermal filler and the polymer aggregate, stir evenly, grind, and obtain the resin; S2. Mix the tetrahydrofuran, the azobisisobutyronitrile and the polydimethylsiloxane, heat and stir until uniform, cool to room temperature, add the diluent and the endothermic solvent, and stir under vacuum to obtain mixture A; S3. Mix the resin described in step S1 and the mixture A described in step S2, and stir until homogeneous to obtain a self-healing coating.

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