A composite modified teflon coating, its preparation method and application

Abstract

The application provides a composite modified Teflon coating and a preparation method and application thereof, and belongs to the technical field of coatings. After a molybdenum carbide / graphite / carbon fiber composite material is prepared, silicon is infiltrated, carbon is increased, and then the composite modified Teflon coating is prepared by mixing the coating with oleic acid modification and ultraviolet absorber UV-328 modified by a silane coupling agent, adding polytetrafluoroethylene emulsion, adding an acrylic monomer, and performing polymerization reaction. The emulsion polymerization method is adopted to copolymerize polytetrafluoroethylene, an acrylic ester and modified materials, a series of composite emulsion coatings with different contents are prepared, the thermal stability, high-temperature resistance, weather resistance, ultraviolet light aging resistance and wear resistance of the coating are improved, the color fastness of the coating is high, the water washing resistance and sunlight resistance are good, the coating has certain hydrophobicity, and the coating has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a composite modified Teflon coating, its preparation method, and its application. Background Technology

[0002] Pigment printing is a simple and rapid coloring method, characterized by a short process flow, easy preparation of printing pastes, wide applicability, and energy conservation and environmental friendliness, making it one of the key development areas in the textile printing and dyeing industry. However, pigment particles lack affinity for fibers and require adhesives to adhere them to the fabric surface. The color fastness and lightfastness of pigment-printed fabrics are closely related to the performance of the adhesive. Currently, water-based polyacrylate adhesives are widely used in pigment printing due to their good adhesion, bright colors, low pollution, and low cost. However, polyacrylates suffer from poor water resistance and thermal brittleness, resulting in poor color fastness of pigment-printed fabrics, which may yellow under high temperatures and outdoor sunlight, failing to meet the requirements of outdoor textiles. Polytetrafluoroethylene (PTFE) is advantageous due to its chemical stability, corrosion resistance, and weather resistance. Coating it onto the fabric surface can simultaneously improve the fabric's weather resistance and hydrophobic properties. However, PTFE exhibits inertness and poor compatibility with other materials, leading to unsatisfactory dispersion. PTFE has low surface tension and poor wettability in water contact, giving it non-stick properties. Therefore, polytetrafluoroethylene / polyacrylate composite latex can be prepared using polyacrylate, offering complementary performance advantages and improving the dispersion and adhesion of PTFE, resulting in an ideal adhesive for coatings. However, it still suffers from poor abrasion resistance, decreased UV resistance due to the addition of polyacrylate resin, poor high-temperature resistance, and poor thermal conductivity. Summary of the Invention

[0003] The purpose of this invention is to propose a composite modified Teflon coating, its preparation method, and its application. Using emulsion polymerization, polytetrafluoroethylene (PTFE) is copolymerized with acrylate and modifying materials to obtain a series of composite emulsion coatings with different contents. This improves the coating's thermal stability, high-temperature resistance, weather resistance, UV aging resistance, and abrasion resistance. The coating also exhibits high color fastness, good water washability and sunlight resistance, and a certain degree of hydrophobicity, showing broad application prospects.

[0004] The technical solution of this invention is implemented as follows:

[0005] This invention provides a method for preparing a composite modified Teflon coating. After preparing a molybdenum carbide / graphite / carbon fiber composite material, it is subjected to silicon infiltration and carbon enrichment, then modified with oleic acid, mixed with UV-328 ultraviolet absorber modified with silane coupling agent, added to polytetrafluoroethylene emulsion, and acrylic monomer is added. The mixture undergoes polymerization reaction to obtain the composite modified Teflon coating.

[0006] As a further improvement to the present invention, the following steps are included:

[0007] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: Molybdenum carbide was ball-milled, then expanded graphite and carbon fiber were added, and plasma-assisted ball milling was performed to obtain the composite material;

[0008] S2. Carbon enrichment: The composite is carbon enriched under nitrogen protection using natural gas as the carbon source and chemical vapor deposition process to obtain a high-density composite.

[0009] S3. Silicon infiltration: The high-density composite is melt-infiltrated with silicon, crushed, and ball-milled to obtain a high-density composite molybdenum-carbon ceramic material;

[0010] S4. Oleic acid modification: High-density composite molybdenum-carbon ceramic powder is mixed with oleic acid and then subjected to plasma-assisted ball milling to obtain modified high-density composite molybdenum-carbon ceramic powder;

[0011] S5. Modification of UV absorber UV-328: UV absorber UV-328 was added to ethanol, silane coupling agent KH570 was added, and the mixture was heated and stirred to react, thus obtaining modified UV absorber UV-328.

[0012] S6. Hydrolysis: Add the modified ultraviolet absorber UV-328 to water, adjust the pH value of the solution, stir and hydrolyze to obtain the hydrolyzed modified ultraviolet absorber UV-328;

[0013] S7. Preparation of composite modified Teflon coating: Emulsifier, pH buffer, and polytetrafluoroethylene emulsion are formulated into an aqueous emulsion, heated and stirred to mix, long-chain alkyl acrylic acid, methyl methacrylate, butyl acrylate, modified high-density composite molybdenum carbon ceramic powder, and hydrolyzed modified ultraviolet absorber UV-328 are added, stirred and mixed evenly, initiator is added, stirred to react, filtered, and discharged to obtain composite modified Teflon coating.

[0014] As a further improvement of the present invention, the mass ratio of molybdenum carbide, expanded graphite and carbon fiber in step S1 is 3-5:1-2:0.5-1, and the power supply parameters of the plasma are: discharge voltage 20-24kV and discharge frequency 10-15kHz.

[0015] As a further improvement of the present invention, the carbon source in the chemical vapor deposition process in step S2 is natural gas or propane gas, the carbon enrichment deposition temperature is 1000-1200℃, and the time is 44-52h; the density of the composite molybdenum-carbon ceramic material in step S3 is 2.3-2.5g / cm³. 3 .

[0016] As a further improvement of the present invention, the mass ratio of the high-density composite molybdenum-carbon ceramic powder to oleic acid in step S4 is 5-7:2-4, and the power supply parameters of the plasma are: discharge voltage 20-24kV and discharge frequency 10-15kHz.

[0017] As a further improvement of the present invention, the mass ratio of the ultraviolet absorber UV-328 and the silane coupling agent KH570 in step S5 is 8-10:2-3, and the temperature of the heating and stirring reaction is 50-60℃, and the time is 2-3h.

[0018] As a further improvement of the present invention, the pH value of the solution is adjusted to 9-10 in step S6, and the stirring and hydrolysis time is 7-10h.

[0019] As a further improvement of the present invention, the mass ratio of the emulsifier, pH buffer, polytetrafluoroethylene emulsion, long-chain alkyl acrylic acid, methyl methacrylate, butyl acrylate, modified high-density composite molybdenum-carbon ceramic powder, hydrolyzed modified ultraviolet absorber UV-328, and initiator in step S7 is 0.2-0.3:0.5-1:4-6:3-5:8-10:0.5-1:2-4:0.5-1:0.001-0.0015. The emulsifier is selected from at least one of Span-20, Span-40, Span-60, Span-80, and Span-85. The pH buffer is sodium bicarbonate or sodium carbonate. The initiator is at least one of ammonium persulfate, potassium persulfate, and sodium persulfate. The long-chain alkyl acrylic acid is selected from at least one of 2-ethylhexyl acrylate and lauryl acrylate. The stirring reaction time is 7-10 hours, and the heating temperature is 75-80°C.

[0020] The present invention further protects a composite modified Teflon coating prepared by the above-described preparation method.

[0021] This invention further protects the application of the aforementioned composite modified Teflon coating in fabric coatings. These fabrics require extremely high abrasion resistance and are used in applications such as extreme sports and outdoor equipment, protective clothing, military uniforms, combat uniforms, and some special-function equipment.

[0022] The present invention has the following beneficial effects:

[0023] This invention involves ball milling a mixture of molybdenum carbide, graphite, and carbon fiber to obtain a composite material. The graphite and carbon fiber encapsulate molybdenum carbide into a core-shell structure composite. Molybdenum carbide serves as a hard phase embedded in the coating, which can significantly reduce wear, enhance high-temperature resistance and oxidation resistance, and improve corrosion resistance. Plasma can generate active groups (such as hydroxyl and carboxyl groups) on the particle surface, breaking up molybdenum carbide agglomerates and enhancing its interfacial bonding with graphite and carbon fiber. At the same time, the uniform dispersion of carbon fiber can construct a three-dimensional support network, providing a mechanical reinforcement basis for subsequent coatings.

[0024] Under the action of chemical vapor deposition, carbon is added and densified, and pores are precisely filled. Under the action of silicon infiltration, silicon reacts with carbon to form SiC phase, which forms a "Mo2C-SiC-graphite" multi-component system with molybdenum carbide, forming a high-density composite molybdenum-carbon ceramic material. It not only has the advantages of good wear resistance, thermal conductivity and reduced friction coefficient of coating, but also improves the high temperature resistance of coating.

[0025] Oleic acid binds to the surface of high-density composite molybdenum-carbon ceramic powder through hydrophobic chains, transforming the "hydrophilic surface" of inorganic powder into a "hydrophobic surface," enabling it to be uniformly dispersed in the aqueous emulsion of polytetrafluoroethylene. This avoids the "layering and agglomeration" problems that occur when mixing inorganic powder with organic emulsions in the traditional way, and improves the surface uniformity of the coating after curing.

[0026] The siloxane groups of KH570 bind to the active sites of UV-328, and the double bonds can copolymerize with monomers such as long-chain alkyl acrylic acid and methyl methacrylate, uniformly fixing the UV absorber UV-328 in the coating crosslinking network. This solves the problem of easy migration and loss of traditional UV absorbers, extending the coating's UV aging resistance life. After hydrolysis, the modified UV absorber UV-328 transforms the silane chain into a silanol structure, increasing its adsorption to the fabric surface, thereby improving wash resistance and color fastness, and also exhibiting good flexibility.

[0027] This invention employs emulsion polymerization to copolymerize polytetrafluoroethylene with acrylate and modifying materials, thereby producing a series of composite emulsion coatings with different contents. This improves the coating's thermal stability, high-temperature resistance, weather resistance, UV aging resistance, and abrasion resistance. The coating also exhibits high color fastness, excellent water washability and sunlight resistance, and a certain degree of hydrophobicity, making it a promising candidate for widespread applications. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a TEM image of the composite modified Teflon coating prepared in Example 1. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides a method for preparing a composite modified Teflon coating, including the following steps:

[0033] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 3g of molybdenum carbide was ball-milled for 1h, then 1g of expanded graphite and 0.5g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 10h. The power supply parameters of the plasma were: discharge voltage 20kV and discharge frequency 10kHz, and the composite material was obtained.

[0034] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1000℃ for 44 hours to obtain a high-density composite.

[0035] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.3 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0036] S4. Oleic acid modification: 5g of high-density composite molybdenum-carbon ceramic powder was mixed with 2g of oleic acid and plasma-assisted ball milling was performed for 15h. The power supply parameters of the plasma were: discharge voltage 20kV and discharge frequency 10kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0037] S5. Modification of UV absorber UV-328: Add 0.8g of UV absorber UV-328 to 50mL of ethanol, add 0.2g of silane coupling agent KH570, heat to 50℃, stir and react for 2h to obtain modified UV absorber UV-328.

[0038] S6. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 9, stir and hydrolyze for 7h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0039] S7. Preparation of composite modified Teflon coating: 0.2g Span-20, 0.5g sodium carbonate, and 4g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 75℃ and stirred. Then, 3g lauryl acrylate, 8g methyl methacrylate, 0.5g butyl acrylate, 2g modified high-density composite molybdenum-carbon ceramic powder, and 0.5g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. Finally, 0.001g ammonium persulfate was added and the mixture was stirred for 7h. After filtration, the product was discharged to obtain the composite modified Teflon coating. Figure 1 The image shows a TEM image of the prepared coating. As can be seen from the image, it has a core-shell structure and good dispersibility, with no aggregation.

[0040] Example 2

[0041] This embodiment provides a method for preparing a composite modified Teflon coating, including the following steps:

[0042] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 5g of molybdenum carbide was ball-milled for 1h, then 2g of expanded graphite and 1g of carbon fiber were added, and plasma-assisted ball milling was carried out for 12h. The power supply parameters of the plasma were: discharge voltage 24kV and discharge frequency 15kHz, and the composite material was obtained.

[0043] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1200℃ for 52 hours to obtain a high-density composite.

[0044] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.35 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0045] S4. Oleic acid modification: 7g of high-density composite molybdenum-carbon ceramic powder was mixed with 4g of oleic acid and plasma-assisted ball milling was performed for 25h. The power supply parameters of the plasma were: discharge voltage 24kV and discharge frequency 15kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0046] S5. Modification of UV absorber UV-328: 1g of UV absorber UV-328 was added to 50mL of ethanol, 0.3g of silane coupling agent KH570 was added, the mixture was heated to 60℃ and stirred for 3h to obtain modified UV absorber UV-328.

[0047] S6. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 10, stir and hydrolyze for 10h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0048] S7. Preparation of composite modified Teflon coating: 0.3g Span-40, 1g sodium bicarbonate, and 6g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 80℃ and stirred. 5g lauryl acrylate, 10g methyl methacrylate, 1g butyl acrylate, 4g modified high-density composite molybdenum-carbon ceramic powder, and 1g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0015g potassium persulfate was added and stirred for 10h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0049] Example 3

[0050] This embodiment provides a method for preparing a composite modified Teflon coating, including the following steps:

[0051] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 4g of molybdenum carbide was ball-milled for 1h, then 1.5g of expanded graphite and 0.7g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, and the composite material was obtained.

[0052] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1100℃ for 48 hours to obtain a high-density composite.

[0053] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.33 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0054] S4. Oleic acid modification: 6g of high-density composite molybdenum-carbon ceramic powder was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0055] S5. Modification of UV absorber UV-328: 0.9g of UV absorber UV-328 was added to 50mL of ethanol, 0.25g of silane coupling agent KH570 was added, the mixture was heated to 55℃ and stirred for 2.5h to obtain modified UV absorber UV-328.

[0056] S6. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 9.5, stir and hydrolyze for 8h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0057] S7. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, 3g modified high-density composite molybdenum-carbon ceramic powder, and 0.7g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0058] Comparative Example 1

[0059] The difference from Example 3 is that molybdenum carbide was not added in step S1.

[0060] Specifically as follows:

[0061] S1. Preparation of graphite / carbon fiber composite material: 1.5g of expanded graphite and 0.7g of carbon fiber were plasma-assisted ball milled for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain the composite material.

[0062] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1100℃ for 48 hours to obtain a high-density composite.

[0063] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.33 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0064] S4. Oleic acid modification: 6g of high-density composite molybdenum-carbon ceramic powder was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0065] S5. Modification of UV absorber UV-328: 0.9g of UV absorber UV-328 was added to 50mL of ethanol, 0.25g of silane coupling agent KH570 was added, the mixture was heated to 55℃ and stirred for 2.5h to obtain modified UV absorber UV-328.

[0066] S6. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 9.5, stir and hydrolyze for 8h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0067] S7. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, 3g modified high-density composite molybdenum-carbon ceramic powder, and 0.7g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0068] Comparative Example 2

[0069] The difference from Example 3 is that step S2 was not performed.

[0070] Specifically as follows:

[0071] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 4g of molybdenum carbide was ball-milled for 1h, then 1.5g of expanded graphite and 0.7g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, and the composite material was obtained.

[0072] S2. Silicon infiltration: The composite material is melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a composite molybdenum-carbon ceramic material;

[0073] S3. Oleic acid modification: 6g of composite molybdenum carbon ceramic powder was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain modified composite molybdenum carbon ceramic powder.

[0074] S4. Modification of UV absorber UV-328: Add 0.9g of UV absorber UV-328 to 50mL of ethanol, add 0.25g of silane coupling agent KH570, heat to 55℃, stir and react for 2.5h to obtain modified UV absorber UV-328.

[0075] S5. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 9.5, stir and hydrolyze for 8h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0076] S6. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, 3g modified composite molybdenum carbon ceramic powder, and 0.7g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0077] Comparative Example 3

[0078] The difference from Example 3 is that step S3 was not performed.

[0079] Specifically as follows:

[0080] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 4g of molybdenum carbide was ball-milled for 1h, then 1.5g of expanded graphite and 0.7g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, and the composite material was obtained.

[0081] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1100℃ for 48 hours to obtain a high-density composite.

[0082] S3. Oleic acid modification: 6g of high-density composite was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain the modified high-density composite.

[0083] S4. Modification of UV absorber UV-328: Add 0.9g of UV absorber UV-328 to 50mL of ethanol, add 0.25g of silane coupling agent KH570, heat to 55℃, stir and react for 2.5h to obtain modified UV absorber UV-328.

[0084] S5. Hydrolysis: Add 1g of modified ultraviolet absorber UV-328 to 50mL of water, adjust the pH of the solution to 9.5, stir and hydrolyze for 8h to obtain hydrolyzed modified ultraviolet absorber UV-328.

[0085] S6. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, 3g modified high-density composite, and 0.7g hydrolyzed modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0086] Comparative Example 4

[0087] The difference from Example 3 is that step S6 was not performed.

[0088] Specifically as follows:

[0089] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 4g of molybdenum carbide was ball-milled for 1h, then 1.5g of expanded graphite and 0.7g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, and the composite material was obtained.

[0090] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1100℃ for 48 hours to obtain a high-density composite.

[0091] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.33 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0092] S4. Oleic acid modification: 6g of high-density composite molybdenum-carbon ceramic powder was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0093] S5. Modification of UV absorber UV-328: 0.9g of UV absorber UV-328 was added to 50mL of ethanol, 0.25g of silane coupling agent KH570 was added, the mixture was heated to 55℃ and stirred for 2.5h to obtain modified UV absorber UV-328.

[0094] S6. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, 3g modified high-density composite molybdenum-carbon ceramic powder, and 0.7g modified ultraviolet absorber UV-328 were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0095] Comparative Example 5

[0096] The difference from Example 3 is that the hydrolyzed modified ultraviolet absorber UV-328 was not added in step S7.

[0097] Specifically as follows:

[0098] S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: 4g of molybdenum carbide was ball-milled for 1h, then 1.5g of expanded graphite and 0.7g of carbon fiber were added, and the mixture was ball-milled with plasma assistance for 11h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, and the composite material was obtained.

[0099] S2. Carbon enrichment: The composite was carbon enriched under nitrogen protection using natural gas as the carbon source by chemical vapor deposition at a deposition temperature of 1100℃ for 48 hours to obtain a high-density composite.

[0100] S3. Silicon Infiltration: The high-density composite was melt-infiltrated with silicon, pulverized, and ball-milled for 6 hours to obtain a density of 2.33 g / cm³. 3 High-density composite molybdenum-carbon ceramic material;

[0101] S4. Oleic acid modification: 6g of high-density composite molybdenum-carbon ceramic powder was mixed with 3g of oleic acid and plasma-assisted ball milling was performed for 20h. The power supply parameters of the plasma were: discharge voltage 22kV and discharge frequency 12kHz, to obtain modified high-density composite molybdenum-carbon ceramic powder.

[0102] S5. Preparation of composite modified Teflon coating: 0.25g Span-85, 0.7g sodium bicarbonate, and 5g polytetrafluoroethylene emulsion were added to 200mL of water to prepare an aqueous emulsion. The emulsion was heated to 77℃ and stirred. 4g lauryl acrylate, 9g methyl methacrylate, 0.7g butyl acrylate, and 3g modified high-density composite molybdenum-carbon ceramic powder were added and stirred for 30min. 0.0012g sodium persulfate was added and stirred for 8h. The mixture was filtered and discharged to obtain the composite modified Teflon coating.

[0103] Test Example 1

[0104] The composite modified Teflon coatings obtained in Examples 1-3 and Comparative Examples 1-5, water-dispersible organic pigments, and thickeners were mixed evenly and then stirred until a certain consistency was reached to obtain a printing paste. This paste was then applied to nylon fabric to obtain printed fabric. The printed fabric was pre-baked at 80°C for 5 minutes and then baked at 170°C for 3 minutes to obtain the dyed and printed fabric.

[0105] K / S value test: using Tests were conducted to compare the color depth of the printed fabrics.

[0106] Water contact angle test: The water contact angle of the printed and dyed fabric surface was tested using a CA200 automatic optical contact angle measuring instrument.

[0107] Color fastness to rubbing test: The Y571B color fastness to rubbing tester was used for testing. The test standard was GB / T3920-2008 "Textiles - Color Fastness Tests - Color Fastness to Rubbing". Then, the printed fabric was rated using the "Grey Chart for Assessment of Staining".

[0108] Sunlight fastness test: using The test was conducted according to GB / T 8427-2019 "Textiles - Tests for color fastness - Color fastness to artificial light".

[0109] Test for fastness to washing with soap: The test standard is GB / T 3921-2008 "Textiles - Tests for color fastness to washing with soap".

[0110] Test for color fastness to perspiration: The test standard is GB / T 3922-2013 "Textiles - Tests for color fastness to perspiration".

[0111] Heat resistance test: The fabric was placed at 140℃ and 90% RH for 120 hours, and the color fastness to dry rubbing was tested.

[0112] The results are shown in Table 1.

[0113] Table 1

[0114] As shown in the table above, the composite modified Teflon coatings prepared in Examples 1-3 of this invention can significantly improve the fabric's resistance to friction, washing, perspiration, and sunlight, with a high K / S value and an increased water contact angle.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a composite modified Teflon coating, characterized in that, After the preparation of the molybdenum carbide / graphite / carbon fiber composite material, silicon infiltration, carbon increase, modification with oleic acid, mixing with ultraviolet absorber UV-328 modified by silane coupling agent, adding into polytetrafluoroethylene emulsion, adding acrylic monomer, polymerization reaction, the composite modified Teflon coating is prepared. The method comprises the following steps: S1. Preparation of molybdenum carbide / graphite / carbon fiber composite material: After ball milling of molybdenum carbide, expandable graphite and carbon fiber are added, and plasma assisted ball milling is performed to obtain a composite; S2. Carbon increase: The composite is carbonized under nitrogen protection by using natural gas as carbon source by using chemical vapor deposition process to obtain a high-density composite; S3. Silicon infiltration: The high-density composite is subjected to molten silicon infiltration, crushing, and ball milling to obtain a high-density composite molybdenum carbon ceramic material; S4. Oleic acid modification: The high-density composite molybdenum carbon ceramic powder is mixed with oleic acid, and plasma assisted ball milling is performed to obtain modified high-density composite molybdenum carbon ceramic powder; S5. Modification of ultraviolet absorber UV-328: The ultraviolet absorber UV-328 is added into ethanol, and silane coupling agent KH570 is added, and heated and stirred to react to obtain modified ultraviolet absorber UV-328; S6. Hydrolysis: The modified ultraviolet absorber UV-328 is added into water, the pH value of the solution is adjusted, and stirring hydrolysis is performed to obtain hydrolyzed modified ultraviolet absorber UV-328; S7. Preparation of composite modified Teflon coating: Emulsifier, pH buffer, polytetrafluoroethylene emulsion are prepared into an aqueous phase emulsion, heated and stirred to mix, long-chain alkyl acrylate, methyl methacrylate, butyl acrylate, modified high-density composite molybdenum carbon ceramic powder, hydrolyzed modified ultraviolet absorber UV-328 are added, stirred and mixed uniformly, initiator is added, stirred to react, filtered, discharged, and the composite modified Teflon coating is prepared.

2. The production method according to claim 1, characterized by, In step S1, the mass ratio of molybdenum carbide, expandable graphite and carbon fiber is 3-5:1-2:0.5-1, and the power parameters of the plasma are: discharge voltage 20-24kV, discharge frequency 10-15kHz.

3. The preparation method according to claim 1, characterized in that, The carbon source of the chemical vapor deposition process in step S2 is natural gas or propane gas, the deposition temperature of the carburization is 1000-1200℃, and the time is 44-52h; the density of the high-density composite molybdenum-carbon ceramic material in step S3 is 2.3-2.5g / cm 3 .

4. The method of claim 1, wherein, In step S4, the mass ratio of high-density composite molybdenum carbon ceramic powder and oleic acid is 5-7:2-4, and the power parameters of the plasma are: discharge voltage 20-24kV, discharge frequency 10-15kHz.

5. The preparation method according to claim 1, characterized in that, In step S5, the mass ratio of ultraviolet absorber UV-328 and silane coupling agent KH570 is 8-10:2-3, the temperature of the heated stirring reaction is 50-60℃, and the time is 2-3h.

6. The method of claim 1, wherein, In step S6, the pH value of the solution is adjusted to 9-10, and the stirring hydrolysis time is 7-10h.

7. The preparation method according to claim 1, characterized in that, The mass ratio of the emulsifier, pH buffer, polytetrafluoroethylene emulsion, long-chain alkyl acrylate, methyl methacrylate, butyl acrylate, modified high-density composite molybdenum carbon ceramic powder, hydrolysis modified ultraviolet absorber UV-328 and initiator in step S7 is 0.2-0.3:0.5-1:4-6:3-5:8-10:0.5-1:2-4:0.5-1:0.001-0.0015, the emulsifier is at least one selected from Span-20, Span-40, Span-60, Span-80, Span-85, the pH buffer is sodium bicarbonate or sodium carbonate, the initiator is at least one selected from ammonium persulfate, potassium persulfate, sodium persulfate, the long-chain alkyl acrylate is at least one selected from 2-ethylhexyl acrylate, lauryl acrylate, the stirring reaction time is 7-10h, and the heating temperature is 75-80℃.

8. A composite modified Teflon coating prepared by the preparation method of any one of claims 1-7.

9. Use of the composite modified Teflon coating of claim 8 in fabric coating.

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