Imitation stone fluorocarbon coating and preparation method thereof

Abstract

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

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a stone-imitation fluorocarbon coating and a preparation method thereof. Background Art

[0002] In the fields of construction, decoration, and industrial protection, coatings are indispensable materials, playing a key role in protecting substrates, enhancing aesthetics, and imparting special functions. With the continuous advancement of society and the increasing appreciation of aesthetic standards, more stringent requirements are being placed on the performance and appearance of coatings. Traditional coatings are increasingly unable to meet the diverse demands of the modern market in terms of weather resistance, corrosion resistance, and decorative effects.

[0003] Paints with imitation stone effects have emerged, aiming to mimic the texture, color, and grain of natural stone, providing elegant and durable decorative solutions for building exteriors and other applications. However, existing imitation stone coatings have numerous shortcomings. Firstly, they lack weather resistance and are susceptible to fading, chalking, and flaking under the long-term effects of environmental factors such as ultraviolet rays, acid rain, and temperature fluctuations, impacting their service life and decorative effect. Secondly, the coatings lack ideal adhesion and bond strength to various substrates, leading to cracking and shedding, especially when the substrate is slightly deformed or subjected to external forces.

[0004] Furthermore, the formulation and preparation processes of some imitation stone coatings are inadequate, resulting in poor rheological and application properties. These include sagging, orange peeling, and uneven particle size, impacting application efficiency and the final appearance. Furthermore, some coatings still contain high levels of volatile organic compounds (VOCs), posing potential hazards to the environment and human health, and failing to comply with increasingly stringent environmental regulations and sustainable development requirements.

[0005] Against this backdrop, the development of a fluorocarbon-based stone-like coating with superior overall performance, realistic decorative effects, and environmental friendliness, along with a scientifically sound preparation process, is crucial. This will not only help drive the coatings industry toward higher performance and higher quality, but also meet market demand for high-end decorative coatings while minimizing negative environmental impacts and providing more reliable and aesthetically pleasing coating solutions for applications such as construction. Summary of the Invention

[0006] The present invention aims to provide a stone-like fluorocarbon coating and its preparation process that has excellent weather resistance, adhesion, lifelike decorative effect and environmental protection, so as to overcome the problems of existing coatings such as easy fading, peeling and insufficient environmental performance.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a stone-like fluorocarbon coating, which is made of the following components in parts by mass: 35-50 parts of fluorocarbon resin, 10-20 parts of nepheline powder, 5-15 parts of potassium aluminum silicate, 3-8 parts of rutile titanium dioxide, 1-5 parts of inorganic color paste, 0.5-2 parts of silane coupling agent, 0.3-1.5 parts of polyamide wax anti-settling agent, 0.5-2 parts of fumed silica, 0.1-0.8 parts of organic silicon leveling agent, 0.2-1 parts of modified hydrogenated castor oil, 5-12 parts of aliphatic isocyanate curing agent, and 10-20 parts of mixed solvent; The silane coupling agent is a compound represented by Formula 1: Formula 1; The R1 is selected from the group consisting of cyano, propyl, methyl, and methylcyano.

[0008] Furthermore, the silane coupling agent is any one of the compounds shown in the following structures: ; .

[0009] Furthermore, the inorganic color paste is an iron oxide color paste, including at least one of iron red, iron yellow or iron black.

[0010] Furthermore, the particle size D50 of the nepheline powder is 10-20 μm, and the particle size D50 of potassium aluminum silicate is 5-15 μm.

[0011] Furthermore, the polyamide wax anti-settling agent is Disibalon 6900-20X.

[0012] Furthermore, the organic silicone leveling agent is BYK-306.

[0013] Furthermore, the aliphatic isocyanate curing agent is BASF Basonat HI100ap.

[0014] Furthermore, the mixed solvent is a mixed solution of xylene and butyl acetate, and the mass ratio of the two is 1:1.

[0015] A method for preparing a stone-like fluorocarbon coating comprises the following steps: S1. The fluorocarbon resin and the mixed solvent were added to a dispersion vessel and stirred at 300-500 rpm for 10 min to obtain material A; S2. To the material A, the nepheline powder, potassium aluminum silicate, rutile titanium dioxide, and inorganic color paste were added and dispersed at 1200-1500 rpm for 30 min to obtain material B; S3. Add the silane coupling agent, polyamide wax anti-settling agent, fumed silica, silicone leveling agent, 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 of ≤25 μm, add the aliphatic isocyanate curing agent at 25±3°C, stir at 400 rpm for 10 min, and filter with an 80-mesh filter to obtain a stone-like fluorocarbon coating.

[0016] Furthermore, the dispersion temperature in S2 is ≤40°C.

[0017] Furthermore, the aliphatic isocyanate curing agent in S4 needs to be pre-dispersed in 1-2 parts of the mixed solvent before being added.

[0018] Furthermore, the grinding in S4 is performed in a grinder, and the grinder uses zirconium beads as grinding media, and the particle size of the zirconium beads is 1.0-1.5 mm.

[0019] The silane alkoxy group in the silane coupling agent of the present invention is hydrolyzed to form silanol, and the Si-OH after hydrolysis undergoes a condensation reaction with the surface of inorganic fillers such as nepheline powder and potassium aluminum silicate, and the filler is "anchored" to the inorganic phase through a covalent bond, thereby reducing interface defects, improving coating adhesion, and preventing filler agglomeration after bonding, thereby ensuring coating uniformity and avoiding uneven particles or sedimentation during construction. The cyano group in the silane coupling agent is an electron acceptor, which forms dipole-dipole interactions or hydrogen bonds with the polar groups of the fluorocarbon resin. Fluorocarbon resin is a hydrophobic polymer, and the polarity of the cyano group makes it more miscible with the resin, reduces phase separation, and improves the leveling 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 the resin network, and improving the hardness and chemical resistance of the coating.

[0020] The stone-like fluorocarbon coating of the present invention overcomes the four major defects of existing stone-like coatings, namely poor weather resistance, insufficient adhesion, poor rheological properties and low environmental performance, through the synergistic effect of the components in the formula and a scientific preparation process. The component synergistic mechanism is based on the principle of "functional complementarity, interface optimization and process synergy". The components are divided into five categories according to their functions and form a hierarchical network. Fluorocarbon resin provides resistance to ultraviolet rays, acid rain and temperature changes by virtue of its high bond energy carbon-fluorine bond, and forms polar interactions with the organic functional groups of the silane coupling agent to reduce defects at the resin-filler interface; the aliphatic isocyanate curing agent reacts with the hydroxyl groups of the fluorocarbon resin during the curing stage to form a cross-linked network. Its aliphatic structure avoids yellowing, and the cyano group of the silane coupling agent may participate in the curing reaction, accelerating cross-linking and enhancing the hardness of the coating. In terms of inorganic fillers and interface modification, nepheline powder and potassium aluminum silicate are used as inorganic fillers and bonded with a silane coupling agent. The silane coupling agent's silane alkoxy groups hydrolyze and condense with the filler surface hydroxyl groups to form Si-O-Si covalent bonds. The cyano groups form a dipole-dipole interaction with the polar groups of the fluorocarbon resin, reducing phase separation and thus enhancing adhesion and durability. Among rheology control and construction additives, polyamide wax anti-settling agents thicken through hydrogen bonding to prevent filler sedimentation. Fumed silica provides pseudoplasticity to inhibit sagging during construction. Silicone leveling agents reduce surface tension and promote coating leveling. Modified hydrogenated castor oil improves pigment dispersion, synergistically optimizing rheological properties and addressing sagging and orange peel issues. The solvent system utilizes a mixed solvent with low toxicity. Combined with high-efficiency components, it reduces total organic volatiles, meeting environmental requirements. The various components form an integrated "resin-filler-additive" network to solve multiple problems such as weather resistance and adhesion, improve workability and coating consistency, enhance environmental protection, and make the coating have excellent weather resistance and adhesion, realistic and environmentally friendly decorative effects, extended service life, and improved construction efficiency.

[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly improved weather resistance: The stone-like fluorocarbon coating of the present invention has excellent weather resistance and can effectively resist the influence of environmental factors such as ultraviolet rays, acid rain, and temperature changes. It significantly reduces the probability of fading, powdering, and peeling, extends the service life of the coating, and ensures long-term and stable decorative effects.

[0022] 2. Greatly improved adhesion: Through the chemical bonding effect of silane coupling agent, the bonding strength between the coating and different substrates is significantly enhanced, reducing problems such as coating cracking and falling off. Especially when the base layer is slightly deformed or impacted by external force, it can still maintain good adhesion performance.

[0023] 3. Significantly enhanced environmental performance: The coating of the present invention adopts a low-toxic mixed solvent system, which reduces the content of organic volatiles, complies with the requirements of environmental protection laws and regulations, and reduces potential harm to the environment and human health. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the HNMR diagram of the silane coupling agent 1 described in the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Preparation Example 1 Synthesis of silane coupling agent 1: ; Step 1: Under a nitrogen atmosphere, 20g of raw material 1, 33.19g of raw material 2, 29.73g of anhydrous potassium carbonate and 250g of a mixed solution of toluene and ethanol (volume ratio 2:1) were added to the reaction system in sequence, stirred evenly, and the nitrogen was replaced twice. Under nitrogen protection, 3.73g of tetrakis(triphenylphosphine)palladium was added to the reaction system, the nitrogen was replaced twice again, and the reaction was heated to 95°C and refluxed for 10 hours. Filter, spin dry, and perform column chromatography using a mixture of petroleum ether and ethyl acetate as eluent, spin dry to obtain 14.51g of intermediate 1. Structural identification: MS [MS+H] of intermediate 1 + :319; Step 2: Under a nitrogen atmosphere, 14.51g of intermediate 1, 16.36g of raw material 3, 12.59g of potassium carbonate, 0.30g of palladium acetate, 0.46g of tri-tert-butylphosphine and 220g of toluene were added to the reaction system, stirred evenly, heated to 110°C, and refluxed for 12h. After the reaction was completed, the temperature was slightly lowered and filtered using diatomaceous earth. After the filtrate was cooled to room temperature, it was filtered, dried, and subjected to column chromatography using a mixture of petroleum ether and ethyl acetate as eluent. It was dried and spun to obtain 18.83g of silane coupling agent 1.

[0027] Structural identification: MS [MS+H] of silane coupling agent 1 + :537; HNMR of silane coupling agent 1: δ7.86(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).

[0028] Preparation Examples 2 to 4 In Preparation Examples 2 to 4, silane coupling agents 2 to 4 were synthesized in sequence, referring to the synthesis method of Preparation Example 1, replacing raw material 1, and remaining the same as Preparation Example 1. Specific raw material structure, silane coupling agent structure, MS [MS + H] + See Table 1 for data.

[0029] Table 1 Structure of raw material 1, silane coupling agent 2-silane coupling agent 4, and MS [MS+H] involved in preparation examples 2 to 4 + data Example 1 Preparation of a stone-like fluorocarbon coating: 1. Components and specific weight parts: Fluorocarbon resin: 40 parts (purchased from Shanghai Flucon Chemical Co., Ltd., No. 9010-75-7); Nepheline powder: 15 parts (particle size D50 is 15 μm); Potassium aluminum silicate: 10 parts (particle size D50 is 10 μm); Rutile titanium dioxide: 5 parts; Inorganic color paste: iron red iron oxide color paste, 3 parts; Silane coupling agent: Silane coupling agent 1 (synthesized according to Preparation Example 1); Polyamide wax anti-settling agent: Diesel Baron 6900-20X, 0.5 parts (purchased from Kusumoto Chemicals Co., Ltd.); Fumed silica: 1 part; Silicone leveling agent: BYK-306, 0.5 parts (purchased from BYK Chemical (Tongling) Co., Ltd.); Modified hydrogenated castor oil: 0.5 parts; Aliphatic isocyanate curing agent: BASF Basonat HI100ap, 8 parts (purchased from BASF SE); Mixed solvent: 10 parts each of xylene and butyl acetate (20 parts in total, mass ratio 1:1).

[0030] 2. Preparation method: S1. 40 parts of fluorocarbon resin and 20 parts of a mixed solvent (10 parts of xylene, 10 parts of butyl acetate) were added to a dispersion vessel and stirred at 400 rpm for 10 minutes to ensure that the resin was fully dissolved in the solvent to obtain a uniform material A; S2. To material A, 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) were added in sequence and dispersed at a speed of 1400 rpm for 30 minutes. During the process, the temperature was strictly controlled at ≤40 ° C to avoid thermal degradation to obtain material B; S3. To material B were added 1 part of a silane coupling agent, 0.5 parts of a polyamide wax anti-settling agent, 1 part of fumed silica, 0.5 parts of a silicone leveling agent and 0.5 parts of modified hydrogenated castor oil, and dispersed at a speed of 800 rpm for 15 minutes to form a stable suspension to obtain material C; S4. Transfer material C to a grinder and grind it to a fineness of ≤25 μm using zirconium beads (particle size 1.2 mm, range 1.0-1.5 mm) as the grinding media. Pre-disperse 8 parts of an aliphatic isocyanate curing agent in 1.5 parts of a mixed solvent (xylene:butyl acetate, 1:1) at 25°C. Add the ground material and stir at 400 rpm for 10 minutes. Finally, filter through an 80-mesh filter to obtain a stone-like fluorocarbon coating.

[0031] Examples 2 to 4 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the silane coupling agent was replaced with silane coupling agent 2 to silane coupling agent 4 prepared in Preparation Examples 2 to 4, and the rest of the process remained the same as that of Example 1.

[0032] Comparative Example 1 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the silane coupling agent was replaced with comparative compound 1 (silane coupling agent KH550), and the rest of the process remained the same as that of Example 1.

[0033] The structure of comparative compound 1 (silane coupling agent kh550) is: .

[0034] Comparative Example 2 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the silane coupling agent was replaced with comparative compound 2, and the rest of the steps were the same as those of Example 1.

[0035] The structure of comparative compound 2 is: .

[0036] Comparative Example 3 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the silane coupling agent was not added, and the rest of the steps were the same as those of Example 1.

[0037] Comparative Example 4 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the mass fraction of potassium aluminum silicate was replaced with 25 parts, and the rest remained the same as in Example 1.

[0038] Comparative Example 5 A stone-like fluorocarbon coating was prepared by referring to the preparation method of Example 1, except that the mass fraction of the polyamide wax anti-settling agent was replaced with 0.1 parts, and the rest remained the same as in Example 1.

[0039] Performance testing: 1. Weathering test: The test method refers to the standard GB / T 1865-2009, artificial weathering 1000H, irradiance: 0.51 (W / m 2 @340nm), BST: 65°C, chamber temperature: 38°C, chamber humidity: 50% RH, Stage 1: Light exposure, 102 minutes, Stage 2: Light exposure, 18 minutes, spraying the front of the specimen, total test time: 1000 hours; result requirements: discoloration ≤ Level 2, gloss loss ≤ Level 2, and no abnormalities such as powdering, bubbles, cracking, and peeling. The final summary test results are shown in Table 2 below.

[0040] 2. Salt Spray Resistance Test: The test method refers to the standard GB / T 10125-2021, and salt spray resistance testing was conducted for 900 hours using an intelligent salt spray corrosion test chamber (E-033-011TD). The test results required: unidirectional corrosion ≤ 2.0 mm on the scribed area; no abnormalities in the unscribed area. The final test results are summarized in Table 2 below.

[0041] 3. Impact resistance test: The testing method refers to the standard GB / T 1732-2020 for impact resistance test.

[0042] Table 2 Performance test data of the stone-like fluorocarbon coatings prepared in the examples and comparative examples The example group showed significant advantages in all performance tests, specifically in terms of weather resistance, with extremely low discoloration and gloss loss, and no powdering, bubbles or cracking; in terms of salt spray resistance, the corrosion range in the scribed area was effectively controlled, and there were no abnormalities in the unscribed area; and impact resistance maintained a high level. In contrast, the performance of the comparative group generally declined, with varying degrees of problems in weather resistance, such as increased discoloration and gloss loss, accompanied by powdering or bubble defects; salt spray resistance showed a higher corrosion risk in both the scribed and unscribed areas; and impact resistance was also significantly weakened. Overall, the formulation using a specific silane coupling agent demonstrated better stability and reliability in terms of weather resistance, corrosion resistance, and mechanical strength than the formulation that replaced or did not add the relevant components, highlighting the synergistic effect of the core components in improving overall performance.

[0043] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A stone-like fluorocarbon coating, characterized in that: The invention is prepared from the following components in parts by mass: 35-50 parts of fluorocarbon resin, 10-20 parts of nepheline powder, 5-15 parts of potassium aluminum silicate, 3-8 parts of rutile titanium dioxide, 1-5 parts of inorganic color paste, 0.5-2 parts of silane coupling agent, 0.3-1.5 parts of polyamide wax anti-settling agent, 0.5-2 parts of fumed silica, 0.1-0.8 parts of organic silicon leveling agent, 0.2-1 parts of modified hydrogenated castor oil, 5-12 parts of aliphatic isocyanate curing agent, and 10-20 parts of mixed solvent; The silane coupling agent is a compound represented by Formula 1: Formula 1; The R1 is selected from the group consisting of cyano, propyl, methyl, and 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 color paste is an iron oxide color paste, including 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 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 Disibalon 6900-20X; The organosilicon 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, and the mass ratio of the two is 1:

1.

7. A method for preparing a stone-like fluorocarbon coating according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. The fluorocarbon resin and the mixed solvent were added to a dispersion vessel and stirred at 300-500 rpm for 10 min to obtain material A; S2. To the material A, the nepheline powder, potassium aluminum silicate, rutile titanium dioxide, and inorganic color paste were added and dispersed at 1200-1500 rpm for 30 min to obtain material B; S3. Add the silane coupling agent, polyamide wax anti-settling agent, fumed silica, silicone leveling agent, 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 of ≤25 μm, add the aliphatic isocyanate curing agent at 25±3°C, stir at 400 rpm for 10 min, 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°C.

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 the 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 performed in a grinder, which uses zirconium beads as grinding media, and the particle size of the zirconium beads is 1.0-1.5 mm.

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