Moisture-resistant single-component polyurea wear-resistant coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a moisture-resistant single-component polyurea wear-resistant coating as well as a preparation method and application thereof. The moisture-resistant single-component polyurea wear-resistant coating provided by the invention is prepared from the following components in parts by weight: 50 to 70 parts of polyurea prepolymer, 20 to 30 parts of wear-resistant filler, 3 to 8 parts of plasticizer, 0.1 to 0.5 part of moisture curing catalyst, 0.2 to 0.5 part of defoaming agent, 0.5 to 1.5 parts of ultraviolet absorbent and 3 to 5 parts of water repellent agent. The coating has very good wear resistance and moisture resistance, and shows better stability in a humid environment.

Description

Technical Field

[0001] This invention belongs to the technical field of coatings, specifically relating to a moisture-resistant single-component polyurea abrasion-resistant coating, its preparation method, and its application. Background Art

[0002] Moisture-resistant, single-component, abrasion-resistant polyurea coating is a high-performance protective material based on polyurea resin. It forms a dense, high-strength elastic coating through a moisture-curing reaction. Its single-component system requires no mixing and can be directly applied. It cures quickly, exhibits excellent abrasion resistance, and achieves a balance between elasticity and hardness, possessing superior abrasion resistance, impact resistance, and chemical corrosion resistance. It has broad application prospects in industrial flooring (warehouses, workshops, parking lots), mining machinery, conveyor belt abrasion protection, water conservancy projects, bridge anti-corrosion and abrasion-resistant coatings, ship decks, and offshore platform protection.

[0003] One-component polyurea coatings offer advantages such as ease of application, but they still have some technical limitations compared to two-component systems. The abrasion resistance and impact resistance of one-component polyurea are generally lower than those of two-component polyurea. One-component polyurea cures through moisture, and curing is slow or even incomplete in low-temperature or low-humidity environments, with deep curing being even more difficult. Because the NCO-terminated prepolymer is sensitive to moisture, one-component polyurea has a shorter shelf life and poor storage stability, requiring strict airtight storage, which limits its application.

[0004] Therefore, how to further improve the performance of single-component polyurea coatings has received increasing attention. Summary of the Invention

[0005] The present invention aims to at least partially solve one of the technical problems in the related art. To this end, embodiments of the present invention provide a moisture-resistant, one-component polyurea abrasion-resistant coating.

[0006] The moisture-resistant single-component polyurea wear-resistant coating of this invention comprises: 50-70 parts of polyurea prepolymer, 20-30 parts of wear-resistant filler, 3-8 parts of plasticizer, 0.1-0.5 parts of moisture-curing catalyst, 0.2-0.5 parts of defoamer, 0.5-1.5 parts of ultraviolet absorber, and 3-5 parts of hydrophobic agent, by weight.

[0007] The advantages and technical effects of the moisture-resistant single-component polyurea wear-resistant coating of the present invention are as follows: 1. In the embodiments of the present invention, the moisture curing catalyst added to the coating can promote the uniformity of the coating and improve the film quality; 2. In the embodiments of the present invention, by adjusting the content of each component, the obtained coating has very good wear resistance and moisture resistance, and exhibits better stability in humid environments.

[0008] In some embodiments, the wear-resistant filler includes at least one of silicon carbide, alumina, or silicon nitride;

[0009] And / or, the wear-resistant filler is surface modified using a silane coupling agent, wherein the particle size of the wear-resistant filler is 10–50 μm.

[0010] In some embodiments, the plasticizer comprises phthalates.

[0011] In some embodiments, the moisture-curing catalyst comprises organotin.

[0012] In some embodiments, the defoamer comprises silicone.

[0013] In some embodiments, the ultraviolet absorber includes at least one of titanium dioxide, benzotriazole, benzophenone, triazine, or hindered amine light stabilizer.

[0014] In some embodiments, the hydrophobic agent comprises fluorinated fumed silica.

[0015] This invention also provides a method for preparing a moisture-resistant one-component polyurea abrasion-resistant coating, comprising the following steps:

[0016] (1) After the wear-resistant filler is dispersed by sand milling, the surface is modified by silane coupling agent to obtain the modified wear-resistant filler;

[0017] (2) Mix the modified wear-resistant filler, polyurea prepolymer, plasticizer, moisture curing catalyst, defoamer, ultraviolet absorber and hydrophobic agent evenly in proportion.

[0018] In some embodiments, in step (1), surface modification includes: dispersing the wear-resistant filler by sand milling, mixing it with 0.1wt% to 0.2wt% of KH-550 silane coupling agent, and stirring evenly to obtain the modified wear-resistant filler.

[0019] The embodiments of the present invention also provide the application of the above-mentioned moisture-resistant single-component polyurea abrasion-resistant coating or the moisture-resistant single-component polyurea abrasion-resistant coating prepared by the above preparation method in environments such as the Gobi Desert and the frozen plateau. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The moisture-resistant single-component polyurea wear-resistant coating of this invention comprises: 50-70 parts of polyurea prepolymer, 20-30 parts of wear-resistant filler, 3-8 parts of plasticizer, 0.1-0.5 parts of moisture-curing catalyst, 0.2-0.5 parts of defoamer, 0.5-1.5 parts of ultraviolet absorber, and 3-5 parts of hydrophobic agent, by weight.

[0022] The moisture-curing catalyst added to the moisture-resistant single-component polyurea wear-resistant coating of this invention can promote the uniformity of the coating and improve the film quality. By adjusting the content of each component, the resulting coating has very good wear resistance and moisture resistance, exhibiting longer stability in humid environments.

[0023] In some embodiments, preferably, the wear-resistant filler comprises at least one of silicon carbide, alumina, or silicon nitride;

[0024] And / or, the wear-resistant filler is surface-modified using a silane coupling agent, wherein the particle size of the wear-resistant filler is 10–50 μm. Surface modification of the wear-resistant filler improves the compatibility between the wear-resistant filler and the polyurea prepolymer.

[0025] In some embodiments, preferably, the plasticizer comprises phthalates. More preferably, the plasticizer comprises at least one selected from dioctyl phthalate, dibutyl phthalate, or diethyl phthalate.

[0026] In some embodiments, preferably, the moisture-curing catalyst comprises organotin. More preferably, the organotin comprises at least one of dibutyltin dilaurate, stannous isooctanoate, dibutyltin diacetate, and their isomers or derivatives.

[0027] In some embodiments, preferably, the defoamer comprises silicone. More preferably, the silicone comprises at least one of polydimethylsiloxane or polyether-modified silicone oil.

[0028] In some embodiments, preferably, the ultraviolet absorber includes at least one of titanium dioxide, benzotriazole, benzophenone, triazine, or hindered amine light stabilizer.

[0029] In some embodiments, preferably, the hydrophobic agent comprises fluorinated fumed silica. The fluorinated fumed silica is sourced from Evonik, product model Aerosil R 8200, and significantly improves the storage stability of one-component polyurea coatings, as well as the moisture resistance of the coating formed from the coating.

[0030] This invention also provides a method for preparing a moisture-resistant one-component polyurea abrasion-resistant coating, comprising the following steps:

[0031] (1) After the wear-resistant filler is dispersed by sand milling, the surface is modified by silane coupling agent to obtain the modified wear-resistant filler;

[0032] (2) Mix the modified wear-resistant filler, polyurea prepolymer, plasticizer, moisture curing catalyst, defoamer, ultraviolet absorber and hydrophobic agent evenly in proportion.

[0033] In some embodiments, preferably, in step (1), surface modification includes: dispersing the wear-resistant filler by sand milling, mixing it with 0.1wt% to 0.2wt% of KH-550 silane coupling agent, and stirring evenly to obtain the modified wear-resistant filler.

[0034] The embodiments of the present invention also provide the application of the above-mentioned moisture-resistant single-component polyurea abrasion-resistant coating or the moisture-resistant single-component polyurea abrasion-resistant coating prepared by the above preparation method in environments such as the Gobi Desert and the frozen plateau.

[0035] The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0036] Example 1

[0037] (1) Use a sand mill to grind and disperse 20 parts of silicon nitride to a fineness of ≤50μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0038] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 3 parts fluorinated fumed silica hydrophobic agent, 0.1 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0039] Example 2

[0040] (1) 20 parts of alumina were ground and dispersed to a fineness of ≤50μm using a sand mill. 0.2 parts of KH-550 were used as a silane coupling agent and the mixture was stirred for 2 hours to obtain modified alumina.

[0041] (2) 20 parts modified alumina, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 3 parts fluorinated fumed silica hydrophobic agent, 0.1 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0042] Example 3

[0043] (1) Use a sand mill to grind and disperse 25 parts of silicon nitride to a fineness of ≤50μm, use 0.25 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0044] (2) 25 parts modified silicon nitride, 60 parts polyurea prepolymer, 4 parts dibutyl phthalate plasticizer, 4 parts fluorinated fumed silica hydrophobic agent, 0.2 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.7 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0045] Example 4

[0046] (1) Use a sand mill to grind and disperse 30 parts of silicon nitride to a fineness of ≤50μm, use 0.3 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 4 hours to obtain modified silicon nitride;

[0047] (2) 30 parts modified silicon nitride, 70 parts polyurea prepolymer, 6 parts dibutyl phthalate plasticizer, 5 parts fluorinated fumed silica hydrophobic agent, 0.5 parts dibutyltin disilicate moisture curing catalyst, 0.5 parts polydimethylsiloxane as defoamer, and 1.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0048] Comparative Example 1

[0049] (1) Use a sand mill to grind and disperse 20 parts of silicon carbide to a fineness of 50-100 μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0050] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 3 parts fluorinated fumed silica hydrophobic agent, 0.1 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0051] Comparative Example 2

[0052] (1) Use a sand mill to grind and disperse 20 parts of silicon carbide to a fineness of ≤50μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0053] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts fluorinated fumed silica hydrophobic agent, 0.1 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0054] Comparative Example 3

[0055] (1) Use a sand mill to grind and disperse 20 parts of silicon carbide to a fineness of ≤50μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0056] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 3 parts fluorinated fumed silica hydrophobic agent, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide ultraviolet absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0057] Comparative Example 4

[0058] (1) Use a sand mill to grind and disperse 20 parts of silicon carbide to a fineness of ≤50μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0059] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 3 parts fumed silica hydrophobic agent, 0.1 parts dibutyltin disilicate moisture curing catalyst, 0.2 parts polydimethylsiloxane as defoamer, and 0.5 parts titanium dioxide UV absorber are stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0060] Comparative Example 5

[0061] (1) Use a sand mill to grind and disperse 20 parts of silicon carbide to a fineness of ≤50μm, use 0.2 parts of KH-550 as a silane coupling agent, and stir with a stirrer for 2 hours to obtain modified silicon nitride;

[0062] (2) 20 parts modified silicon nitride, 50 parts polyurea prepolymer, 3 parts dibutyl phthalate plasticizer, 0.1 parts dibutyltin dibutylsilicate moisture curing catalyst, and 0.2 parts polydimethylsiloxane were used as defoamers and stirred evenly in a stirrer to obtain a single-component polyurea coating.

[0063] The single-component polyurea coatings prepared in Examples 1-4 and Comparative Examples 1-5 were applied to the surface of Q235 steel substrates to form coatings. The water contact angle, roll-off angle, adhesion, and abrasion resistance of the coatings were then tested, and the results are shown in Table 1. Specifically, the coating adhesion was tested using the pull-off method according to GB / T 5210-2006 "Standard for Adhesion Test of Paints and Varnishes by Pull-Off Method". The abrasion resistance was tested using the reciprocating module of an MS-M9000 friction testing machine, with Si3N4 as the friction pair, applying a 10N load to the coating sample on the surface of the Q235 steel substrate at a reciprocating frequency of 2Hz.

[0064] Table 1

[0065] Water contact angle (°) Roll angle (°) Adhesion abrasion resistance Example 1 152 3 10MPa Minor scratches Example 2 135 3 9.6MPa Less wear Example 3 155 3 9.8MPa Minor scratches Example 4 148 4 9.5MPa Minor scratches Comparative Example 1 126 4 6MPa Significant wear Comparative Example 2 138 3 - Obvious scratches Comparative Example 3 115 6 5N Obvious scratches Comparative Example 4 108 4 8N Minor scratches Comparative Example 5 105 10 9N Minor scratches

[0066] As can be seen from the data in Table 1, the coatings formed by the coatings prepared using Examples 1 to 4 of the present invention have better hydrophobicity, adhesion and wear resistance.

[0067] Compared with Example 1, Example 2 uses alumina as the wear-resistant filler. Although the overall performance is still good and meets the requirements, the coating in Example 2 has a certain degree of wear and the wear resistance is slightly reduced because the hardness of alumina is less than that of silicon nitride.

[0068] Compared with Example 1, Example 3 adjusted the composition of the coating, and the various indicators remained almost unchanged. This shows that when the wear-resistant filler is increased, the other filler components of the coating are adjusted accordingly to ensure the film quality and wear resistance of the coating.

[0069] Compared to Example 1, Example 4 further increases the content of silicon nitride wear-resistant filler and appropriately adjusts the content of key components such as plasticizer, organotin catalyst, and fluorinated fumed silica to fully utilize the functional advantages of these components in dispersing the wear-resistant filler and avoid the decrease in coating wear resistance due to filler sedimentation. It is necessary to simultaneously pay attention to adjusting the content of key components such as plasticizer and organotin catalyst; excessive addition of wear-resistant filler will cause sedimentation, leading to a decrease in the wear resistance of the coating, a decline in film quality, or even failure to form a film.

[0070] Compared with Example 1, Comparative Example 1 showed that replacing the particle size of the wear-resistant filler with 50-100 μm resulted in a coating with reduced hydrophobicity, reduced adhesion, and poorer wear resistance. This indicates that excessively large abrasive particle size is not suitable for this coating film-forming system, and further improvements to the coating formulation are needed to ensure the quality of the coating film.

[0071] Compared with Example 1, Comparative Example 2 did not add phthalate plasticizer. Phthalate plasticizer improves the toughness of the coating by embedding it into the polymer chain, thus preventing the coating from cracking under load after film formation. In this comparative example, the absence of phthalate plasticizer caused the coating to crack during the adhesion test, and the adhesion could not be measured.

[0072] Compared to Example 1, Comparative Example 3, which did not include an organotin moisture-curing catalyst, showed reduced hydrophobicity, decreased adhesion to 5N, and worsened abrasion resistance. This is because organotin catalysts promote coating uniformity and improve film quality; the absence of organotin catalysts leads to a decline in film quality or even prevents film formation.

[0073] Compared with Example 1, Comparative Example 4 replaced fluorinated fumed silica with fumed silica. Although the resulting coating had good wear resistance, its hydrophobicity and adhesion were significantly reduced. This indicates that fluorinated fumed silica can further improve the hydrophobicity of the coating compared with fumed silica, which is of great significance for extending the durability of the coating in humid climates.

[0074] Compared with Example 1, Comparative Example 5, without the addition of fluorinated fumed silica and titanium dioxide, produced a coating with good wear resistance, but its hydrophobicity and adhesion were significantly reduced. This indicates that fluorinated fumed silica and titanium dioxide play an important role in ensuring the hydrophobicity and UV aging resistance of the coating. The lack of relevant functional fillers will lead to a decrease in the durability of the coating.

[0075] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A moisture-resistant, one-component polyurea abrasion-resistant coating, characterized in that, include: The composition is as follows: 50-70 parts polyurea prepolymer, 20-30 parts wear-resistant filler, 3-8 parts plasticizer, 0.1-0.5 parts moisture-curing catalyst, 0.2-0.5 parts defoamer, 0.5-1.5 parts ultraviolet absorber, and 3-5 parts hydrophobic agent, by weight.

2. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The wear-resistant filler includes at least one of silicon carbide, alumina, or silicon nitride. And / or, the wear-resistant filler is surface modified using a silane coupling agent, wherein the particle size of the wear-resistant filler is 10–50 μm.

3. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The plasticizer includes phthalates.

4. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The moisture-curing catalyst includes organotin.

5. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The defoamer includes organosilicon.

6. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The ultraviolet absorber includes at least one of titanium dioxide, benzotriazole, benzophenone, triazine, or hindered amine light stabilizer.

7. The moisture-resistant single-component polyurea abrasion-resistant coating according to claim 1, characterized in that, The hydrophobic agent includes fluorinated fumed silica.

8. The method for preparing the moisture-resistant single-component polyurea abrasion-resistant coating according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) After the wear-resistant filler is dispersed by sand milling, the surface is modified by silane coupling agent to obtain the modified wear-resistant filler; (2) Mix the modified wear-resistant filler, polyurea prepolymer, plasticizer, moisture curing catalyst, defoamer, ultraviolet absorber and hydrophobic agent evenly in proportion.

9. The method for preparing the moisture-resistant single-component polyurea abrasion-resistant coating according to claim 8, characterized in that, In step (1), surface modification includes: dispersing the wear-resistant filler by sand milling, mixing it with 0.1wt% to 0.2wt% of KH-550 silane coupling agent, and stirring evenly to obtain the modified wear-resistant filler.

10. The application of the moisture-resistant single-component polyurea abrasion-resistant coating according to any one of claims 1 to 7 or the moisture-resistant single-component polyurea abrasion-resistant coating prepared by the preparation method according to claim 8 or 9 in environments such as the Gobi Desert and frozen plateau.