Natural marble self-cleaning anti-erosion surface treatment process
By constructing a gradient composite coating of a nano-titanium dioxide photocatalytic layer and a hydrophobic micro-nano structure surface layer on the surface of natural marble, the problems of weak coating adhesion and incomplete self-cleaning mechanism are solved, achieving stable and efficient industrial production and long-lasting self-cleaning and anti-corrosion effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, the surface treatment coatings for natural marble have weak adhesion to the stone substrate, making it difficult to achieve stable and efficient continuous industrial production. Furthermore, it is difficult to simultaneously achieve the dual self-cleaning mechanism of photocatalytic decomposition of organic pollutants and superhydrophobic rolling droplets, resulting in easy degradation of coating performance and cumbersome process steps.
Atmospheric pressure plasma jet is used to activate the stone surface, constructing a nano-titanium dioxide photocatalytic layer and a hydrophobic micro-nano structure surface layer. Through liquid phase deposition, electrostatic atomization spraying and gradient curing processes, a functionally graded composite coating is formed, which enhances the bonding force and achieves long-lasting self-cleaning and anti-corrosion functions.
It achieves a strong bond between the coating and the substrate, has long-lasting self-cleaning and corrosion resistance capabilities, and the coating performance is stable, making it suitable for mass production.
Smart Images
Figure CN121820146A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of marble surface treatment, and particularly relates to a natural marble self-cleaning and anti-erosion surface treatment process. BACKGROUND
[0002] Natural stone is widely used in building decoration due to its beauty and durability. However, its porous surface is easy to adsorb dust and pollutants, and is prone to corrosion and discoloration under the environment of acid rain, pollutants and the like, and the maintenance cost is high. In order to endow the stone with self-cleaning function, the existing technology often adopts the method of surface coating photocatalytic material or constructing super-hydrophobic coating.
[0003] However, the existing technical solutions usually have limitations: 1. A single functional coating cannot simultaneously achieve the dual self-cleaning mechanisms of photocatalytic decomposition of organic pollutants and super-hydrophobic rolling of liquid droplets; 2. The adhesion between the coating and the stone substrate is weak, and the coating is easy to peel off under the action of outdoor thermal stress, mechanical friction and the like, and the durability is poor; 3. The performance of the functional coating is easy to decay under the action of light, pollution and the like; 4. Most of the process steps are complicated, and it is difficult to realize stable and efficient industrialized continuous production; therefore, it is urgent to develop a natural marble self-cleaning and anti-erosion surface treatment process which can be combined firmly, has durable function and is suitable for large-scale production. SUMMARY
[0004] In order to overcome the shortcomings of the existing technical solutions that the adhesion between the coating and the stone substrate is weak, the process steps are complicated, and it is difficult to realize stable and efficient industrialized continuous production, the technical problem to be solved by the present application is to provide a natural marble self-cleaning and anti-erosion surface treatment process which can be combined firmly, has durable function and is suitable for large-scale production.
[0005] The present application is achieved by the following specific technical means: A natural marble self-cleaning and anti-erosion surface treatment process, comprising the following steps: Step one, substrate pretreatment: the stone plate is subjected to thickness determination, grinding and polishing to obtain a substrate with a smooth surface; Step two, surface activation: the substrate is sent into a plasma surface treatment bin, and an atmospheric pressure plasma jet is used to scan and treat the decorative surface of the substrate to realize cleaning and activation; Step three, construction of a photocatalytic layer: the activated substrate is transferred to a liquid deposition device, and a uniform nanometer titanium dioxide hydrogel film is generated on the surface of the substrate through liquid deposition reaction; then the substrate is sent into a heat treatment furnace for crystallization to form a nanometer structure bottom layer with photocatalytic activity; Step four, constructing super-hydrophobic surface layer: on the photocatalytic bottom layer obtained in step three, use the working fluid containing nano-silicon dioxide particles pre-modified by fluorosilane surface and hydrophobic resin, and perform high-voltage electrostatic atomization spraying through the electrostatic atomization spraying station to form a uniform liquid film; then, the sprayed substrate is sent into a drying box to volatilize the solvent and preliminarily crosslink the resin under the set temperature and humidity conditions, so as to fix and form a hydrophobic composite layer with micro-nano rough structure on the photocatalytic bottom layer; Step five, gradient curing: the plate is sent into a gradient curing box to sequentially undergo medium infrared preheating, ultraviolet light post-curing and circulating air cooling and stabilization treatment. Step six, inspection and sorting: the finished plate is subjected to non-contact scanning detection and automatic sorting by using an inspection and sorting system.
[0006] Further, in step two, the working gas of the atmospheric pressure plasma jet is argon, nitrogen or a mixed gas thereof, the scanning speed is 10-100 mm / s, and the power density is 0.5-5 W / cm².
[0007] Further, in step three, the precursor solution used for the liquid deposition reaction is a mixed aqueous solution containing tetraisopropyl titanate, deionized water and nitric acid, the pH value is controlled at 1.5-3.0, the reaction temperature is 40-60°C, and the deposition time is 10-30 minutes; the heating temperature of the heat treatment furnace is 150-300°C, and the crystallization time is 15-60 minutes.
[0008] Further, in step five, the specific conditions of the gradient curing are as follows: the medium infrared preheating temperature is 60-90°C, and the time is 2-5 minutes; the ultraviolet curing adopts ultraviolet light with a wavelength of 365 nm, the irradiation intensity is 80-200 mW / cm², and the time is 30-90 seconds; and the air cooling temperature is controlled at 25-40°C.
[0009] An integrated preparation device for a natural marble self-cleaning anti-erosion surface treatment process, characterized by comprising, in sequence along a production line: A plasma surface treatment bin, in which an atmospheric pressure plasma jet device is arranged, for scanning cleaning and activation of a substrate; A liquid deposition device, including a temperature-controllable reaction tank or a spraying system, for generating a uniform nano-titanium dioxide hydrogel film on the substrate surface; A chain heat treatment furnace, for crystallization treatment of the substrate covered with the gel film to form a photocatalytic active bottom layer; An electrostatic atomization spraying station, for spraying a working fluid containing modified nanoparticles and hydrophobic resin on the photocatalytic bottom layer; A drying box, for preliminary curing of the sprayed liquid film; A gradient curing box is provided with a middle infrared preheating module, an ultraviolet post-curing module and a temperature control air cooling module in sequence, and is used for gradient curing of a coating. An inspection and sorting system is integrated with a laser profilometer and a contact angle measuring instrument, and is connected with an automatic sorting mechanical arm, and is used for inspection and sorting of finished products.
[0010] A natural marble prepared by a self-cleaning anti-erosion surface treatment process, the decorative surface of which has a functional gradient composite coating from inside to outside; including a nano-titanium dioxide photocatalytic bottom layer closely combined with the substrate, the layer having photocatalytic activity and a certain surface roughness; and a hydrophobic micro-nano structure surface layer constructed on the photocatalytic bottom layer, the surface layer being composed of nano-silicon dioxide particles modified by fluorosilane and hydrophobic resin to form a stable super-hydrophobic interface.
[0011] Further, the nano-silicon dioxide particles in the hydrophobic micro-nano structure surface layer have a bimodal particle size distribution, the main peak particle size being 50-100 nm and the secondary peak particle size being 10-20 nm.
[0012] Further, the thickness of the hydrophobic micro-nano structure surface layer is 5-20 microns, and the surface roughness Ra is 0.1-1.0 μm.
[0013] Further, the thickness of the nano-titanium dioxide photocatalytic bottom layer is 100-500 nanometers, and the content of anatase phase in the crystal structure thereof is not less than 80%.
[0014] Compared with the prior art, the present application has the following beneficial effects: By constructing the gradient composite coating of the photocatalytic bottom layer and the super-hydrophobic surface layer, a synergistic self-cleaning mechanism of photocatalytic decomposition of organic matter and super-hydrophobic rolling off of pollutants is realized; the surface layer protects the bottom layer from pollution and covering, the bottom layer decomposes the organic pollutants reaching the surface layer, and the hydrophobic performance is delayed from decaying, so that long-acting self-cleaning and anti-erosion ability are obtained.
[0015] The plasma activation is adopted to enhance the activity of the substrate, the photocatalytic layer is firmly combined with the substrate through liquid deposition; the super-hydrophobic layer is anchored with the bottom layer through resin bonding, and the internal stress is optimized through a gradient curing process, so that the bonding force of the entire composite coating with the stone substrate is extremely strong, and the weather resistance and wear resistance are significantly improved. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The figure is a process flow diagram of the present application. DETAILED DESCRIPTION
[0017] The present application is further described below in combination with the drawings: EMBODIMENT
[0018] A natural marble self-cleaning anti-erosion surface treatment process, as shown inFigure 1 As shown, comprising the following steps: Step one, substrate pretreatment: the stone plate is thickened, ground and polished to obtain a flat substrate; Step two, surface activation: the substrate is sent into the plasma surface treatment bin, and the decorative surface is scanned and treated by atmospheric pressure plasma jet to realize cleaning and activation; Step three, building a photocatalytic layer: the activated substrate is transferred to a liquid deposition device to generate a uniform nanometer titanium dioxide hydrogel film on the substrate surface through liquid deposition reaction; then the substrate is sent into a heat treatment furnace for crystallization to form a nano-structured bottom layer with photocatalytic activity; Step four, building a super-hydrophobic surface layer: on the photocatalytic bottom layer obtained in step three, use a working liquid containing nano-silicon dioxide particles pre-modified by fluorosilane surface and hydrophobic resin to form a uniform liquid film by high-voltage electrostatic atomization spraying through an electrostatic atomization spraying station; then, the sprayed substrate is sent into a drying box to evaporate the solvent and preliminarily crosslink the resin under the set temperature and humidity conditions, so as to fix a layer of hydrophobic composite layer with micro-nano rough structure on the photocatalytic bottom layer; Step five, gradient curing: the plate is sent into a gradient curing box and sequentially subjected to medium infrared preheating, ultraviolet light post-curing and circulating air cooling and stabilization treatment; Step six, inspection and sorting: the finished plate is subjected to non-contact scanning detection and automatic sorting by using an inspection and sorting system.
[0019] Working principle: The present application focuses on the construction and synergistic mechanism of functional gradient composite coating, and forms a protective layer with high adhesion, long-lasting photocatalytic activity and stable super-hydrophobic properties on the surface of stone through the combination of physical and chemical methods, so as to realize long-acting self-cleaning and corrosion resistance.
[0020] Overall, the coating structure is divided into two layers with complementary functions: the bottom layer is a nanometer titanium dioxide photocatalytic layer formed by liquid deposition and crystallization, which can produce strong oxidizing holes and hydroxyl radicals under light, mainly used for chemical decomposition of organic pollutants attached to the surface; the surface layer is a micro-nano rough structure composed of fluorosilane modified nano-silicon dioxide particles and hydrophobic resin, which endows the surface with super-hydrophobicity, can physically repel water droplets and make them roll off, while carrying away dust and inorganic particles; the hydrophobic layer greatly reduces the contact area and time of water, stains and coating and stone substrate, thereby physically blocking the invasion of corrosive media.
[0021] A self-sustaining synergistic cycle is formed between the two layers of functions: the superhydrophobic surface layer reduces the adhesion and residence of pollutants; while the photocatalytic layer can decompose a small amount of organic pollutants that break through the hydrophobic barrier or deposit in the recesses of the microstructure, preventing their accumulation from causing a decrease in hydrophobicity; the two work together to ensure the long-term stability of the coating functions.
[0022] In terms of structural design, the coating gradually transitions from the inorganic photocatalytic layer chemically bonded to the substrate to the hydrophobic functional layer, effectively avoiding interface stress concentration caused by differences in material properties; the nanostructure of the photocatalytic layer provides the upper hydrophobic resin with a high specific surface area and anchoring points, and the resin can partially penetrate into the nanopores to form mechanical interlocking; fluorosilane-modified nanosilica particles not only have hydrophobicity but also can be well combined with the resin and firmly coated; the subsequent gradient curing process, including infrared preheating, ultraviolet curing, and programmed air cooling, promotes the uniform crosslinking of the resin from the inside out, gently releasing the shrinkage stress, thereby preventing the coating from producing cohesive cracking or detaching from the bottom layer due to rapid curing, ensuring the overall cohesion of the composite coating and its adhesion to the substrate.
[0023] The starting point of the process chain is plasma activation treatment: atmospheric pressure plasma jet bombards the stone surface with high-energy particles and active particles, achieving deep cleaning, nanoscale micro-etching, and surface activation, removing organic residues and weak boundary layers while increasing surface roughness and introducing active groups such as hydroxyl groups, creating an ideal chemical bonding interface for subsequent deposition.
[0024] On this basis, the photocatalytic layer is constructed by liquid deposition: on the activated hydrophilic surface, the hydrolysis and condensation reaction of the acidic precursor solution is controlled to make titanium dioxide precursor molecules uniformly adsorb and directly nucleate and grow into a hydrated gel film on the substrate surface; this surface-controlled reaction can form a uniform and dense film that is firmly bonded on complex curved surfaces; subsequent moderate-temperature heat treatment promotes the conversion of amorphous gel into high-photocatalytic-activity anatase nanocrystals and further strengthens the bonding with the substrate through dehydration and condensation.
[0025] The formation of micro-nano structures is achieved through electrostatic atomization spraying: high-voltage electrostatic atomization disperses the working liquid into fine droplets with the same charge, which are attracted to the grounded substrate under the action of electric field force, forming a uniform and thickness-controllable liquid film; this method not only avoids the phenomenon of sagging, but also improves the uniformity of the coating through the electrostatic self-leveling effect; the modified nanoparticles in the liquid film are fixed to form stable micro-nano secondary rough structures through the synergistic action of self-assembly and solidification during the solvent evaporation and resin crosslinking process, which is the key to obtaining durable superhydrophobicity.
[0026] Finally, the gradient energy field curing process further integrates the coating system: the mid-infrared preheating gently warms the coating, promoting solvent evaporation and resin pre-crosslinking; the ultraviolet curing initiates rapid and deep crosslinking of the resin, forming a high-strength three-dimensional network structure that firmly locks the nanoparticles; the program-controlled air cooling process gently reduces the temperature, avoiding thermal stress concentration caused by the difference in thermal expansion coefficient, thereby improving the stability of the coating in a temperature changing environment.
[0027] In summary, the present application builds a gradient composite functional coating on the surface of the stone through a series of surface treatment and deposition processes, which has strong adhesion in the inner layer, can photocatalytically decompose organic matter, has super-hydrophobicity in the outer layer, and can physically block pollution; each step of the process lays the foundation for the interface for the subsequent steps, and the subsequent steps further consolidate and strengthen the overall performance, ultimately under the protection of the special integrated device, efficiently and stably preparing a stone plate with long-acting self-cleaning and corrosion-resistant functions.
[0028] Although the present disclosure has been described in detail with reference to exemplary embodiments, the present disclosure is not limited thereto and it will be apparent to those skilled in the art that various modifications and changes can be made thereto without departing from the scope of the present disclosure.
Claims
1. A self-cleaning and erosion-resistant surface treatment process for natural marble, characterized in that, Includes the following steps: Step 1: Substrate pretreatment: The stone slabs are subjected to thickness determination, grinding and polishing to obtain a substrate with a smooth surface; Step 2, Surface activation: The substrate is sent into the plasma surface treatment chamber, and atmospheric pressure plasma jet is used to scan its decorative surface to achieve cleaning and activation; Step 3: Constructing the photocatalytic layer: The activated substrate is transferred to a liquid phase deposition device, and a uniform nano-titanium dioxide hydrated gel film is generated on the substrate surface through a liquid phase deposition reaction. The substrate is then sent to a heat treatment furnace for crystallization to form a nanostructure bottom layer with photocatalytic activity. Step 4: Constructing a superhydrophobic surface layer: On the photocatalytic substrate obtained in Step 3, a working solution containing nano-silica particles with pre-modified fluorosilane surface and hydrophobic resin is applied by high-pressure electrostatic atomization spraying through an electrostatic atomization spraying workstation to form a uniform liquid film. Subsequently, the coated substrate is sent into a drying oven, where the solvent evaporates and the resin undergoes initial cross-linking under set temperature and humidity conditions, thereby fixing a hydrophobic composite layer with a micro-nano rough structure on the photocatalytic substrate. Step 5, Gradient Curing: The board is sent into the gradient curing chamber and undergoes mid-infrared preheating, ultraviolet post-curing, and circulating air cooling stabilization treatment in sequence. Step Six: Inspection and Sorting: Use the inspection and sorting system to perform non-contact scanning inspection and automatic sorting of finished boards.
2. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 1, characterized in that, In step two, the working gas of the atmospheric pressure plasma jet is argon, nitrogen, or a mixture thereof, the scanning speed is 10-100 mm / s, and the power density is 0.5-5 W / cm².
3. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 1, characterized in that, In step three, the precursor solution used in the liquid phase deposition reaction is a mixed aqueous solution containing tetraisopropyl titanate, deionized water and nitric acid, with its pH value controlled at 1.5-3.0, the reaction temperature at 40-60℃, and the deposition time at 10-30 minutes; the heating temperature of the heat treatment furnace is 150-300℃, and the crystallization time is 15-60 minutes.
4. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 1, characterized in that, In step five, the specific conditions for gradient curing are as follows: mid-infrared preheating temperature 60-90℃, time 2-5 minutes; ultraviolet curing uses ultraviolet light with a wavelength of 365nm, irradiation intensity of 80-200 mW / cm², time 30-90 seconds; air cooling temperature is controlled at 25-40℃.
5. An integrated preparation apparatus for carrying out the process described in claim 1, characterized in that, The production line includes, in sequence: The plasma surface treatment chamber is equipped with an atmospheric pressure plasma jet device for scanning, cleaning and activating the substrate. Liquid phase deposition apparatus, including a temperature-controlled reaction tank or spraying system, for generating a uniform nano-titanium dioxide hydrated gel film on a substrate surface. A chain heat treatment furnace is used to crystallize a substrate coated with a gel film to form a photocatalytically active bottom layer. An electrostatic atomizing spraying workstation is used to spray a working liquid containing modified nanoparticles and hydrophobic resin onto a photocatalytic substrate. A drying oven is used to allow the sprayed liquid film to initially cure. The gradient curing chamber is equipped with a mid-infrared preheating module, an ultraviolet post-curing module, and a temperature-controlled air-cooling module, which are used for gradient curing of the coating. The inspection and sorting system integrates a laser profilometer and a contact angle measuring instrument, and is connected to an automatic sorting robotic arm for inspecting and sorting finished products.
6. A stone slab with self-cleaning and anti-corrosion functions prepared by the method described in claim 1, characterized in that, Its decorative surface features a functionally graded composite coating from the inside out; It includes a nano-titanium dioxide photocatalytic underlayer that is tightly bonded to the substrate. This layer has photocatalytic activity and a certain surface roughness. And a hydrophobic micro / nano structure surface layer built on the photocatalytic substrate, which is composed of fluorosilane-modified nano silica particles and hydrophobic resin to form a stable superhydrophobic interface.
7. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 6, characterized in that, The nano-silica particles in the surface layer of the hydrophobic micro / nano structure have a bimodal particle size distribution, with the main peak particle size being 50-100 nm and the secondary peak particle size being 10-20 nm.
8. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 6, characterized in that, The thickness of the surface layer of the hydrophobic micro / nano structure is 5-20 micrometers, and the surface roughness Ra is 0.1-1.0 μm.
9. The self-cleaning and erosion-resistant surface treatment process for natural marble according to claim 6, characterized in that, The thickness of the nano-titanium dioxide photocatalytic substrate is 100-500 nanometers, and the content of the anatase phase in its crystal structure is not less than 80%.