Stone-like fluorocarbon coating and preparation method thereof

Abstract

The application relates to the field of paint technology and relates to a stone-imitating fluorocarbon paint and a preparation method thereof. The stone-imitating fluorocarbon paint is prepared from the following components in parts by mass: fluorocarbon resin 35-50 parts, nepheline powder 10-20 parts, potassium aluminosilicate 5-15 parts, rutile titanium dioxide 3-8 parts, inorganic color paste 1-5 parts, silane coupling agent 0.5-2 parts, polyamide wax anti-settling agent 0.3-1.5 parts, fumed silica 0.5-2 parts, organic silicon leveling agent 0.1-0.8 parts, modified hydrogenated castor oil 0.2-1 part, aliphatic isocyanate curing agent 5-12 parts and mixed solvent 10-20 parts. The stone-imitating fluorocarbon paint has excellent weather resistance, can effectively resist the influence of environmental factors such as ultraviolet rays, acid rain and temperature change, significantly reduces the occurrence probability of phenomena such as discoloration, powdering and peeling, prolongs the service life of the paint and ensures long-term stable decoration effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, in particular to a kind of stone-like fluorocarbon coating and preparation method thereof. BACKGROUND

[0002] In the field of building, decoration and industrial protection, coatings as indispensable materials play a key role in protecting substrates, enhancing aesthetics and imparting special functions. With the continuous progress of society and the increasing improvement of people's aesthetic concept, more stringent requirements are put forward for the performance and appearance effect of coatings. Traditional coatings have gradually been difficult to meet the diversification needs of modern market in terms of weather resistance, corrosion resistance and decorative effect, etc.

[0003] Stone-like coatings emerge as the times require, aiming to simulate the texture, color and texture of natural stone, providing elegant and durable decorative solutions for building facades, etc. However, existing stone-like coatings have many shortcomings. On the one hand, their weather resistance is not good, and under the long-term action of environmental factors such as ultraviolet light, acid rain and temperature change, they are prone to problems such as fading, chalking and peeling, affecting service life and decorative effect. On the other hand, the adhesion of the coating is not ideal, and the combination with different substrates is not firm enough, which can easily lead to cracking and peeling of the coating, especially when the substrate is slightly deformed or subjected to external impact.

[0004] In addition, the formulation and preparation process of some stone-like coatings are not perfect, resulting in poor rheological properties and construction performance of the coatings, such as sagging, orange peel, uneven particles, etc., affecting construction efficiency and final appearance quality. In terms of environmental performance, some coatings still contain high amounts of organic volatile substances, which pose potential hazards to the environment and human health, and do not meet the increasingly stringent environmental regulations and the requirements of sustainable development.

[0005] Under this background, it is particularly urgent to develop a stone-like fluorocarbon coating with excellent comprehensive performance, realistic decorative effect and environmental protection, as well as a scientific and reasonable preparation process. This not only helps to promote the development of the coatings industry towards high performance and high quality, but also meets the market demand for high-end decorative coatings, while reducing the negative impact on the environment, providing more reliable and beautiful coating solutions for the building and other fields. SUMMARY

[0006] The present application aims to provide a stone-like fluorocarbon coating with excellent weather resistance, adhesion, realistic decorative effect and environmental protection, as well as a preparation process thereof, to overcome the problems of existing coatings such as fading, peeling and insufficient environmental performance.

[0007] To achieve the above object, the technical scheme adopted by the present application is: a kind of stone-like fluorocarbon coating, which is made of the following components by mass fraction: fluorocarbon resin 35-50 parts, nepheline powder 10-20 parts, potassium aluminosilicate 5-15 parts, rutile titanium dioxide 3-8 parts, inorganic color paste 1-5 parts, silane coupling agent 0.5-2 parts, polyamide wax anti-settling agent 0.3-1.5 parts, fumed silica 0.5-2 parts, silicone leveling agent 0.1-0.8 parts, modified hydrogenated castor oil 0.2-1 part, aliphatic isocyanate curing agent 5-12 parts, mixed solvent 10-20 parts;

[0008] The silane coupling agent is a compound represented by formula 1:

[0009] Formula 1;

[0010] R1 is selected from: cyano, propyl, methyl, methyl cyano.

[0011] Further, the silane coupling agent is a compound represented by any one of the following structures:

[0012] ;

[0013] .

[0014] Further, the inorganic color paste is an iron oxide-based color paste, which contains at least one of iron red, iron yellow or iron black.

[0015] Further, the particle size D50 of the nepheline powder is 10-20 μm, and the particle size D50 of the potassium aluminosilicate is 5-15 μm.

[0016] Further, the polyamide wax anti-settling agent is Desbapon 6900-20X.

[0017] Further, the silicone leveling agent is BYK-306.

[0018] Further, the aliphatic isocyanate curing agent is BASF Basonat HI100ap.

[0019] Further, the mixed solvent is a mixed solution of dimethylbenzene and butyl acetate, and the mass fraction ratio of the two is 1:1.

[0020] A preparation method of a stone-like fluorocarbon coating, comprising the following steps:

[0021] S1. Add the fluorocarbon resin and mixed solvent to a dispersion kettle, and stir at 300-500 rpm for 10 min to obtain material A;

[0022] S2. Add the nepheline powder, potassium aluminosilicate, rutile titanium dioxide, inorganic color paste to the material A, disperse at 1200-1500 rpm for 30 min, to obtain material B;

[0023] S3. Add the silane coupling agent, polyamide wax anti-settling agent, fumed silica, silicone leveling agent, modified hydrogenated castor oil to the material B, disperse at 800 rpm for 15 min, to obtain material C;

[0024] S4. Grind the material C to a fineness of ≤25 μm, add the aliphatic isocyanate curing agent at 25±3℃, stir at 400 rpm for 10 min, filter with an 80 mesh screen, to obtain a stone-like fluorocarbon coating.

[0025] Further, the temperature of the dispersion in S2 is ≤40℃.

[0026] Further, the aliphatic isocyanate curing agent in S4 needs to be pre-dispersed in 1-2 parts of mixed solvent before being added.

[0027] Further, the grinding in S4 is carried out in a grinding machine using zirconium bead grinding media with a particle size of 1.0-1.5 mm.

[0028] The silane group in the silane coupling agent in the present application hydrolyzes to form silanol, and the hydrolyzed Si-OH reacts with the surface of the inorganic fillers such as nepheline powder and potassium aluminosilicate to form a covalent bond, which "anchors" the fillers in the inorganic phase, reduces the interface defects, improves the adhesion of the coating, prevents the agglomeration of the fillers after bonding, ensures the uniformity of the coating, and avoids uneven particles or sedimentation during construction. The cyano group in the silane coupling agent is an electron acceptor, which forms a dipole-dipole interaction or hydrogen bond with the polar group of the fluorocarbon resin. Fluorocarbon resin is a hydrophobic polymer, and the polarity of cyano group makes it more miscible with the resin, reduces phase separation, and improves the leveling property of the coating. During the curing stage, the cyano group may participate in the reaction of the aliphatic isocyanate curing agent, indirectly promoting the formation of resin network, improving the hardness and chemical resistance of the coating.

[0029] The stone-like fluorocarbon coating of the present application aims at the four defects of poor weather resistance, insufficient adhesion, poor rheological properties and low environmental performance of existing stone-like coatings, which are overcome by the synergistic effect of each component in the formula and scientific preparation process. The component synergistic mechanism is based on the principle of "functional complementation, interface optimization and process synergy", and each component is divided into five categories according to function and forms a hierarchical network. Fluorocarbon resin provides resistance to ultraviolet light, acid rain and temperature variation with high bond energy carbon-fluorine bond, and forms a polar interaction with the organic functional groups of silane coupling agent to reduce resin-filler interface defects; aliphatic isocyanate curing agent reacts with the hydroxyl groups of fluorocarbon resin to form a crosslinked network during the curing stage, its aliphatic structure avoids yellowing, and the cyano group of the silane coupling agent may participate in the curing reaction to accelerate crosslinking and enhance the hardness of the coating. In terms of inorganic fillers and interface modification, nepheline powder and potassium aluminum silicate are bonded by silane coupling agent, and the silanol of silane coupling agent hydrolyzes and condenses with the surface hydroxyl groups of the filler to form Si-O-Si covalent bonds, its cyano group forms a dipole-dipole interaction with the polar groups of fluorocarbon resin to reduce phase separation, thereby enhancing adhesion and durability. In rheological control and construction aid, polyamide wax anti-settling agent prevents settling by hydrogen bonding thickening, fumed silica provides pseudoplasticity to inhibit construction sag, silicone leveling agent reduces surface tension to promote coating leveling, and modified hydrogenated castor oil improves pigment dispersion, synergistically optimizing rheological properties to solve sagging and orange peel problems. The solvent system uses mixed solvents, which are low in toxicity and cooperate with high-efficiency components to reduce total organic volatile matter, meeting environmental protection requirements. Each component forms an integrated network of "resin-filler-aid", solving problems such as weather resistance, adhesion, and improving construction performance and coating consistency, enhancing environmental performance, making the coating have excellent weather resistance, adhesion, realistic decorative effect, environmental protection, long service life and high construction efficiency.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] 1. Weather resistance is significantly improved: The stone-like fluorocarbon coating of the present application performs well in weather resistance, effectively resisting the influence of environmental factors such as ultraviolet light, acid rain and temperature changes, significantly reducing the probability of phenomena such as fading, powdering and peeling, prolonging the service life of the coating and ensuring long-term stable decorative effect.

[0032] 2. Adhesion is greatly improved: Through the chemical bonding of silane coupling agent, the bonding force between the coating and different substrates is significantly enhanced, reducing problems such as coating cracking and peeling, especially when the base layer is slightly deformed or subjected to external force impact, it still maintains good adhesion performance.

[0033] 3. Environmental performance is significantly enhanced: The coating of the present application uses a low-toxicity mixed solvent system, reducing the content of organic volatile matter, meeting the requirements of environmental regulations and reducing potential harm to the environment and human health. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 HNMR chart of silane coupling agent 1 described in the present application. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] Preparation Example One

[0037] Synthesis of silane coupling agent 1:

[0038] ;

[0039] First step: under nitrogen atmosphere, 20 g of raw material 1, 33.19 g of raw material 2, 29.73 g of anhydrous potassium carbonate and 250 g of a mixed solution of toluene and ethanol (volume ratio 2:1) were sequentially added into the reaction system, stirred uniformly, and replaced with nitrogen twice. Under nitrogen protection, 3.73 g of tetrakis(triphenylphosphine)palladium was added into the reaction system, and nitrogen was replaced twice again. The reaction was heated to 95℃ and refluxed for 10 hours. Filtration, spin-drying, column chromatography, using a mixture of petroleum ether and ethyl acetate as eluent, spin-drying, 14.51 g of intermediate 1 was obtained. Structure identification: MS [MS+H] of intermediate 1 + : 319;

[0040] Second step: under nitrogen atmosphere, 14.51 g of intermediate 1, 16.36 g of raw material 3, 12.59 g of potassium carbonate, 0.30 g of palladium acetate, 0.46 g of tri-tert-butylphosphine and 220 g of toluene were added into the reaction system, stirred uniformly, heated to 110℃, and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, and filtration was performed using diatomite. After the filtrate was cooled to room temperature, filtration, spin-drying, column chromatography, using a mixture of petroleum ether and ethyl acetate as eluent, spin-drying, 18.83 g of silane coupling agent 1 was obtained.

[0041] Structure identification: MS [MS+H] of silane coupling agent 1 + : 537;

[0042] HNMR of silane coupling agent 1 : δ 7.86 (d, 1H), 7.58 (m, 1H), 7.39 (dd, 1H), 6.95 (m, 1H), 5.38 (q, 1H), 4.71 (m, 1H), 3.75 (q, 1H), 3.65-3.53 (m, 9H), 2.62 (m, 2H), 2.09 (s, 3H), 1.69-1.51 (m, 7H), 1.51 (d, 3H), 1.34 (d, 3H), 0.82-0.68 (m, 2H).

[0043] Preparation Examples Two to Four

[0044] Silane coupling agents 2-4 were synthesized in turn in Preparation Examples Two to Four, referring to the synthesis method of Preparation Example One, replacing raw material 1 therein, and the rest being the same as Preparation Example One. The structures of the raw material 1, silane coupling agents 2-4, and MS [MS+H] are as follows. + The data are shown in Table 1.

[0045] Table 1. Structures of raw material 1, silane coupling agents 2-4, and MS [MS+H] involved in Preparation Examples Two to Four + Data

[0046]

[0047] Example One

[0048] Preparation of a stone-like fluorocarbon coating

[0049] 1. Components and specific mass parts:

[0050] Fluorocarbon resin: 40 parts (purchased from Shanghai Fluorine Chemical Co., Ltd., No. 9010-75-7);

[0051] Nepheline powder: 15 parts (particle size D50 is 15 μm);

[0052] Potassium aluminosilicate: 10 parts (particle size D50 is 10 μm);

[0053] Rutile titanium dioxide: 5 parts;

[0054] Inorganic color paste: iron red iron oxide color paste, 3 parts;

[0055] Silane coupling agent: silane coupling agent 1 (synthesized according to Preparation Example One);

[0056] Polyamide wax anti-settling agent: Disparlon 6900-20X, 0.5 parts (purchased from Nanben Chemical Industry Co., Ltd.);

[0057] Fumed silica: 1 part;

[0058] Silicone leveling agent: BYK-306, 0.5 parts (purchased from: BYK-Chemical (Tongling) Co., Ltd.);

[0059] Modified hydrogenated castor oil: 0.5 parts;

[0060] Aliphatic isocyanate curing agent: BASF Basonat HI100ap, 8 parts (purchased from: BASF SE);

[0061] Mixed solvent: xylene and butyl acetate, each 10 parts (total 20 parts, mass ratio 1:1).

[0062] 2. Preparation method:

[0063] S1. Add 40 parts of fluorocarbon resin and 20 parts of mixed solvent (10 parts of xylene, 10 parts of butyl acetate) into a dispersion kettle, stir at a speed of 400 rpm for 10 minutes to ensure that the resin is fully dissolved in the solvent, and obtain a uniform material A;

[0064] S2. Add 15 parts of nepheline powder, 10 parts of potassium aluminum silicate, 5 parts of rutile titanium dioxide, and 3 parts of inorganic color paste (iron red iron oxide color paste) to material A in turn, and disperse at a speed of 1400 rpm for 30 minutes. The temperature is strictly controlled at ≤40℃ during the process to avoid thermal degradation, and material B is obtained;

[0065] S3. Add 1 part of silane coupling agent, 0.5 parts of polyamide wax anti-settling agent, 1 part of fumed silica, 0.5 parts of silicone leveling agent, and 0.5 parts of modified hydrogenated castor oil to material B, and disperse at a speed of 800 rpm for 15 minutes to form a stable suspension system, and obtain material C;

[0066] S4. Transfer material C to a grinding machine, use zirconium beads as grinding medium (particle size 1.2 mm, range 1.0-1.5 mm), and grind to a fineness of ≤25 μm. At an ambient temperature of 25℃, 8 parts of aliphatic isocyanate curing agent is pre-dispersed in 1.5 parts of mixed solvent (xylene and butyl acetate 1:1), then added to the ground material, stirred at a speed of 400 rpm for 10 minutes, and finally filtered with an 80 mesh screen to obtain a stone-like fluorocarbon coating.

[0067] Examples two to four

[0068] A stone-like fluorocarbon coating is prepared by referring to the preparation method of Example 1, and replacing the silane coupling agent in Example 1 with the silane coupling agents 2-4 prepared in Preparation Examples two to four in turn, and the rest remains the same as Example 1.

[0069] Comparative Example one

[0070] A kind of stone-like fluorocarbon coating preparation, with reference to the preparation method of example one, the silane coupling agent in it is replaced with comparative compound 1 (silane coupling agent kh550), the rest is same with example one.

[0071] The structure of comparative compound 1 (silane coupling agent kh550) is: 。

[0072] Comparative example two

[0073] A kind of stone-like fluorocarbon coating preparation, with reference to the preparation method of example one, the silane coupling agent in it is replaced with comparative compound 2, the rest is same with example one.

[0074] The structure of comparative compound 2 is: 。

[0075] Comparative example three

[0076] A kind of stone-like fluorocarbon coating preparation, with reference to the preparation method of example one, the silane coupling agent in it is not added, the rest is same with example one.

[0077] Comparative example four

[0078] A kind of stone-like fluorocarbon coating preparation, with reference to the preparation method of example one, the mass fraction of potassium aluminium silicate in it is replaced with 25 parts, the rest is same with example one.

[0079] Comparative example five

[0080] A kind of stone-like fluorocarbon coating preparation, with reference to the preparation method of example one, the mass fraction of polyamide wax anti-settling agent in it is replaced with 0.1 parts, the rest is same with example one.

[0081] Performance test:

[0082] 1. Weather resistance test: detection method refers to standard GB / T 1865-2009, artificial climate aging 1000H, irradiance: 0.51 (W / m 2 @340nm), BST: 65 DEG C, box temperature: 38 DEG C, box humidity: 50%RH, stage 1: light, 102 min, stage 2: light, 18 min, spray sample front, total test time: 1000h;Result requirement: discoloration ≤2 level, light loss ≤2 level, no abnormal phenomenon such as powdering, bubble, cracking, peeling etc. The final test result is shown in the following table 2.

[0083] 2. Salt mist resistance test: The detection method refers to the standard GB / T 10125-2021, and the 900H salt mist resistance test is carried out. The intelligent salt mist corrosion test box is used, the instrument number is E-033-011TD, and the results require that the single rust corrosion of the line is less than or equal to 2.0mm, and there is no abnormality in the non-line area. The final test results are shown in Table 2 as follows.

[0084] 3. Impact resistance test: The detection method refers to the standard GB / T 1732-2020, and the impact resistance test is carried out.

[0085] Table 2 Performance test data of stone-like fluorocarbon coatings prepared in examples and comparative examples

[0086]

[0087] The example group shows significant advantages in all performance tests, specifically, the degree of discoloration and loss of luster is extremely low, and there is no any peeling, blistering or cracking phenomenon; in terms of salt mist resistance, the corrosion range of the line area is effectively controlled, and there is no abnormality in the non-line area; the impact resistance maintains a high level. In contrast, the performance of the comparative example group generally declines, among which the weather resistance appears different degrees of problems such as discoloration and loss of luster, accompanied by peeling or blistering defects; the salt mist resistance shows higher corrosion risk in the line area and the non-line area; the impact resistance is also significantly weakened. Overall, the formula using the specific silane coupling agent compared to the formula replacing or not adding the relevant components, in terms of weather resistance, corrosion resistance and mechanical strength, all embodies better stability and reliability, highlighting the synergistic effect of the core component in improving the overall performance.

[0088] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A stone-like fluorocarbon coating, characterized in that, It is made from the following components in parts by weight: 35-50 parts fluorocarbon resin, 10-20 parts nepheline powder, 5-15 parts potassium aluminum silicate, 3-8 parts rutile titanium dioxide, 1-5 parts inorganic pigment, 0.5-2 parts silane coupling agent, 0.3-1.5 parts polyamide wax anti-settling agent, 0.5-2 parts fumed silica, 0.1-0.8 parts organosilicon leveling agent, 0.2-1 parts modified hydrogenated castor oil, 5-12 parts aliphatic isocyanate curing agent, and 10-20 parts mixed solvent; The silane coupling agent is a compound represented by Formula 1: Formula 1; R1 is selected from: cyano, propyl, methyl, methylcyano.

2. The stone-like fluorocarbon coating according to claim 1, characterized in that, The silane coupling agent is any one of the compounds shown in the following structures: ； 。 3. The stone-like fluorocarbon coating according to claim 1, characterized in that, The inorganic pigment is an iron oxide-based pigment, containing at least one of iron red, iron yellow, or iron black.

4. The stone-like fluorocarbon coating according to claim 1, characterized in that, The particle size D50 of the nepheline powder is 10-20 μm, and the particle size D50 of the potassium aluminum silicate is 5-15 μm.

5. The stone-like fluorocarbon coating according to claim 1, characterized in that, The polyamide wax anti-settling agent is DISPA 6900-20X; The silicone leveling agent is BYK-306; The aliphatic isocyanate curing agent is BASF Basonat HI100ap.

6. The stone-like fluorocarbon coating according to claim 1, characterized in that, The mixed solvent is a mixed solution of xylene and butyl acetate, with a mass ratio of 1:

1.

7. A method for preparing a stone-like fluorocarbon coating according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Add the fluorocarbon resin and mixed solvent to a dispersion vessel and stir at 300-500 rpm for 10 min to obtain material A; S2. Add the nepheline powder, potassium aluminum silicate, rutile titanium dioxide, and inorganic color paste to the material A, and disperse at 1200-1500 rpm for 30 min to obtain material B; S3. Add the silane coupling agent, polyamide wax anti-settling agent, fumed silica, organosilicon leveling agent, and modified hydrogenated castor oil to the material B, and disperse at 800 rpm for 15 min to obtain material C; S4. Grind the material C to a fineness ≤25μm, add the aliphatic isocyanate curing agent at 25±3℃, stir at 400rpm for 10min, and filter with an 80-mesh filter to obtain a stone-like fluorocarbon coating.

8. The method for preparing a stone-like fluorocarbon coating according to claim 7, characterized in that, The dispersion temperature in S2 is ≤40℃.

9. The method for preparing a stone-like fluorocarbon coating according to claim 7, characterized in that, The aliphatic isocyanate curing agent in S4 needs to be pre-dispersed in 1-2 parts of mixed solvent before being added.

10. The method for preparing a stone-like fluorocarbon coating according to claim 7, characterized in that, The grinding in S4 is carried out in a grinding machine, which uses zirconium bead grinding media with a particle size of 1.0-1.5 mm.

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