A protective layer for a field-mounted magnetic light for oil fields

Abstract

The application discloses a protective layer for an installation-free magnetic lamp in an oil field and a preparation method thereof, and belongs to the technical field of coating. The protective layer is attached to the magnetic attraction plate surface of the installation-free magnetic lamp. A plurality of magnets are uniformly distributed on the magnetic attraction plate surface of the installation-free magnetic lamp. The magnets are neodymium-iron-boron magnets. The static suction force of a single magnet is greater than 20 kg. The protective layer comprises a bottom layer and a release layer. The bottom layer comprises isocyanate group modified fluorocarbon resin, NHS activated ester modified mica flake modified nano magnetic powder compound, ethylene-vinyl alcohol copolymer, n-butyl acetate, dibutyl phthalate, polycarboxylate dispersant and 3-isocyanate group propyl trimethoxysilane. The release layer comprises isocyanate group modified fluorocarbon resin, acrylate polyol, poly N-isopropyl acrylamide modified pressure sensitive viscosity microspheres and silane coupling agent. The application solves the problems of oil stains and rust.

Description

Technical Field

[0001] This invention belongs to the field of coating technology and relates to a protective layer for use in oilfields where magnetic lamps can be installed without installation. Background Technology

[0002] The installation-free magnetic lamp utilizes the strong magnetic attraction properties of neodymium iron boron magnets to quickly and easily attach to the surface of iron-based equipment for fixation, enabling rapid assembly and disassembly. It can be applied to nighttime operation scenarios such as oilfield drilling, well repair, and inspection. However, the working environment at oilfield sites is harsh, with a large amount of oil, debris, dust, and moisture. The magnetic plate (neodymium iron boron magnet) of the magnetic lamp is exposed to this complex environment for a long time. Debris, oil, and other impurities easily adhere to the magnetic plate, which is difficult to clean. Over time, this accumulation will reduce the magnetic adhesion and make the magnetic lamp easy to fall off during use. In addition, oil and moisture can easily penetrate into the magnet, causing the magnet to rust and shortening the life of the magnetic lamp. Summary of the Invention

[0003] The purpose of this invention is to provide a protective layer for installation-free magnetic lamps in oilfields, which solves the problem that oil, debris and other contaminants accumulate on the magnetic plate surface during long-term use of installation-free magnetic lamps in oilfields, reducing the magnetic adhesion.

[0004] The technical solution adopted in this invention is as follows: A protective layer for installation-free magnetic lamps in oilfields is provided. The protective layer is attached to the magnetic suction plate of the installation-free magnetic lamp. Multiple evenly distributed magnets are installed on the magnetic suction plate of the installation-free magnetic lamp. The magnets are neodymium iron boron magnets, and the static attraction force of a single magnet is greater than 20 kg. The protective layer includes a base layer and a release layer. The base layer is fully coated on the magnetic suction plate of the installation-free magnetic lamp, and the release layer covers the base layer and the area of ​​the release layer is larger than the area of ​​the magnetic suction plate. The bottom layer comprises the following components in parts by weight: 48-55 parts isocyanate-modified fluorocarbon resin, 22-28 parts NHS activated ester modified mica flake modified nano-magnetic powder composite, 10-12 parts ethylene-vinyl alcohol copolymer, 15-18 parts n-butyl acetate, 3-5 parts dibutyl phthalate, 2-3 parts polycarboxylate dispersant, and 4-5 parts 3-isocyanate-propyltrimethoxysilane; The release layer comprises the following components in parts by weight: 42-48 parts isocyanate-modified fluorocarbon resin, 34-36 parts acrylate polyol, 10-12 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 2-3 parts silane coupling agent.

[0005] Furthermore, the nano-magnetic powder is composed of nano-carbonyl iron powder and nano-ferric oxide magnetic powder, with a mass ratio of nano-carbonyl iron powder to nano-ferric oxide magnetic powder of 3:(2~2.5); the particle size of the nano-carbonyl iron powder is 60-80nm, and the particle size of the nano-ferric oxide magnetic powder is 50-70nm.

[0006] Furthermore, the NHS-activated ester-modified mica flake-modified nano-magnetic powder composite is prepared by the following method: S1.1, nano carbonyl iron powder, and nano iron oxide magnetic powder are mixed evenly to obtain nano magnetic powder. The nano magnetic powder is added to an ethanol aqueous solution with a volume ratio of 3:1 and ultrasonically dispersed to obtain a nano magnetic powder suspension. 5% (by weight) of 3-aminopropyltriethoxysilane is added to the nano magnetic powder suspension, the temperature is raised to 60℃, and the reaction is carried out for 2-2.5 hours under stirring. The mixture is then filtered and dried to obtain pretreated nano magnetic powder. S1.2 Add mica flakes to dichloromethane at a solid-liquid ratio of 1g:10ml, stir evenly, then add 9% succinic anhydride by weight of mica flakes, heat to 70℃, stir at constant temperature for 3 hours, filter to obtain modified mica flakes; add the modified mica flakes to MES buffer solution at pH 6 and disperse evenly, then add EDC and NHS at a molar ratio of 1:(1.3~1.5), react at room temperature for 3 hours, filter, dry the precipitate, and obtain NHS activated ester modified mica flakes; S1.3. The pretreated nano-magnetic powder and NHS activated ester modified mica flakes were mixed at a mass ratio of (2.7~2.9):1 to obtain a mixture. The mixture was placed in a phosphate buffer solution with a pH of 7.3-7.5, and after being dispersed evenly, it was reacted at room temperature for 2-3 hours. The mixture was then filtered, dried, and the precipitate was dried to obtain the NHS activated ester modified mica flake modified nano-magnetic powder composite.

[0007] Furthermore, the bottom layer and the release layer are made of the same isocyanate-modified fluorocarbon resin; the isocyanate-modified fluorocarbon resin is prepared from diisocyanate, fluorocarbon resin and modified acrylic monomer in a molar ratio of 2:1:1 as raw materials; wherein the modified acrylic monomer is prepared by mixing thiol with acrylic monomer and photoinitiator under inert gas protection and carrying out mercapto-vinyl click reaction at room temperature to obtain hydroxyl-terminated modified acrylic monomer.

[0008] Further, the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were prepared by the following method: Deionized water was taken, and sodium dodecyl sulfate was added at a concentration of 0.3% of the deionized water mass. After stirring and dissolving, butyl acrylate, methyl methacrylate, and N-isopropylacrylamide were added, stirred evenly, and ultrasonically dispersed for 10 min to form a uniform emulsion system. Nitrogen gas was introduced into the emulsion system to remove oxygen. Then, ammonium persulfate was added at a concentration of 0.5% of the total mass of butyl acrylate, methyl methacrylate, and N-isopropylacrylamide. The temperature was raised to 70°C, and the mixture was stirred at a constant temperature for 16-18 h. After filtration, washing, and drying, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were obtained.

[0009] Furthermore, the ethylene-vinyl alcohol copolymer is obtained by copolymerizing ethylene and vinyl alcohol in a mass ratio of 2.8:(7~7.3).

[0010] Further, the bottom layer is prepared by the following method: ethylene-vinyl alcohol copolymer is dissolved in an organic solvent to obtain an ethylene-vinyl alcohol copolymer solution; isocyanate-modified fluorocarbon resin and n-butyl acetate are uniformly mixed, and then the ethylene-vinyl alcohol copolymer solution is added under stirring. After mixing evenly, dibutyl phthalate, polycarboxylate dispersant, 3-isocyanate-based propyltrimethoxysilane, and NHS activated ester modified mica flake modified nano-magnetic powder composite are added sequentially under stirring. After stirring evenly, the mixture is dispersed at high speed to obtain the bottom layer slurry; the slurry is uniformly coated on a clean and dry magnetic plate surface and cured to obtain the bottom layer.

[0011] Further, the release layer is prepared by the following method: isocyanate-modified fluorocarbon resin and acrylate polyol are mixed in a dry container, and after uniform mixing, a silane coupling agent is added and the mixture is stirred until uniform. Then, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are slowly added at a stirring speed of 200-300 r / min. After the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are added and uniformly dispersed, a mixed adhesive solution is obtained. The mixed adhesive solution is vacuum degassed and then uniformly coated onto a release film. It is then completely cured at 45-55℃. After complete curing, it is cooled to 20℃ to obtain the release layer. In use, the side of the release layer that is different from the release film is pressed and adhered to the bottom layer to bond the release layer to the magnetic plate surface.

[0012] Furthermore, the thickness of the bottom layer is 0.03-0.05 mm.

[0013] Furthermore, the thickness of the peeling layer is 0.45-0.55 mm.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention provides a protective layer for installation-free magnetic lamps in oilfields, comprising a base layer and a release layer. The base layer is directly coated on the magnetic plate surface of the installation-free magnetic lamp to form a waterproof and oil-proof protective effect, reducing the amount of oil and pollutants adhering to the magnetic plate surface and solving the problems of oil and rust. However, the base layer creates a physical barrier between the magnetic plate and the iron-based support, which reduces the magnetic attraction strength. Therefore, to compensate for this defect, this application adds an NHS activated ester modified mica flake modified nano-magnetic powder composite to the base layer, which is uniformly dispersed in the base layer and has magnetic attraction function, playing a role in magnetic attraction compensation and reducing the degree of decrease in magnetic attraction strength. 2. In this invention, the NHS-activated ester-modified mica flake-modified nano-magnetic powder plays a magnetic compensation role in the bottom layer, thus giving the bottom layer a magnetic function. When not in use (idle, stored, or moved), it is easy for iron debris from the environment to adhere to it. A large amount of debris adheres to the magnetic plate surface, which not only causes surface wear but also reduces the magnetic adhesion. Therefore, a release layer is introduced into the protective layer of this application. The release layer is not magnetic and uses isocyanate-based modified fluorocarbon resin as the main resin. The surface is not easily contaminant-adhered, thus playing a role in preventing oil stains, water, and debris. 3. In this invention, the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres in the release layer are the main pressure-sensitive adhesive component. After modification with poly(N-isopropylacrylamide), they exhibit temperature sensitivity. When heated to a temperature exceeding the critical phase transition temperature, the adhesion strength between the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres and the underlying layer decreases, allowing the release layer to be peeled off completely. When the release layer is placed in air and the temperature is below the critical temperature, the adhesiveness of the surface containing the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres will relatively increase again, allowing for repeated use. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a structural diagram of the magnetic lamp used in this invention; Figure 2 This is a structural diagram of the magnetic absorbing plate surface of the present invention; Figure 3 The preparation process of NHS-activated ester-modified mica flakes modified nano-magnetic powder composite.

[0016] Markings in the diagram: 1-Adhesive plate, 2-Mounting plate, 3-Magnetic sleeve, 4-Magnet. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0020] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0021] This invention provides a protective layer for an installation-free magnetic lamp in an oilfield. The protective layer is attached to the magnetic plate surface of the installation-free magnetic lamp. Multiple evenly distributed magnets are installed on the magnetic plate surface of the installation-free magnetic lamp. The magnets are neodymium iron boron magnets, and the static attraction force of a single magnet is greater than 20 kg. The protective layer includes a base layer and a release layer. The base layer is fully coated on the magnetic plate surface of the installation-free magnetic lamp, and the release layer covers the base layer and the area of ​​the release layer is larger than the area of ​​the magnetic plate surface. The bottom layer comprises the following components in parts by weight: 48-55 parts isocyanate-modified fluorocarbon resin, 22-28 parts NHS activated ester modified mica flake modified nano-magnetic powder composite, 10-12 parts ethylene-vinyl alcohol copolymer, 15-18 parts n-butyl acetate, 3-5 parts dibutyl phthalate, 2-3 parts polycarboxylate dispersant, and 4-5 parts 3-isocyanate-propyltrimethoxysilane; the polycarboxylate dispersant actually adopts DS8637 comb-structured polycarboxylate nano-dispersant. The release layer comprises the following components in parts by weight: 42-48 parts isocyanate-modified fluorocarbon resin, 34-36 parts acrylate polyol, 10-12 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 2-3 parts silane coupling agent (KH550 silane coupling agent is used).

[0022] In the following embodiments, the nano-magnetic powder is composed of nano-carbonyl iron powder and nano-ferric oxide magnetic powder, with a mass ratio of nano-carbonyl iron powder to nano-ferric oxide magnetic powder of 3:2.2; the particle size of nano-carbonyl iron powder is 60-80 nm, and the particle size of nano-ferric oxide magnetic powder is 50-70 nm.

[0023] like Figure 3 As shown, in the following embodiments, the NHS-activated ester-modified mica flake-modified nano-magnetic powder composite was prepared by the following method: S1.1. Nano carbonyl iron powder and nano iron oxide magnetic powder are mixed evenly to obtain nano magnetic powder. The nano magnetic powder is added to an ethanol aqueous solution with a volume ratio of 3:1 and ultrasonically dispersed to obtain a nano magnetic powder suspension. 5% (by weight of nano magnetic powder) of 3-aminopropyltriethoxysilane is added to the nano magnetic powder suspension, the temperature is raised to 60℃, and the reaction is carried out for 2.5 hours under stirring. The mixture is then filtered and dried to obtain pretreated nano magnetic powder. S1.2. Mica flakes were added to dichloromethane at a solid-liquid ratio of 1g:10ml. After stirring evenly, succinic anhydride at 9% of the mica flake mass was added. The mixture was heated to 70℃ and stirred at a constant temperature for 3 hours. The mixture was then filtered to obtain modified mica flakes. The modified mica flakes were then dispersed evenly in MES buffer solution at pH 6. EDC and NHS at a molar ratio of 1:1.4 were then added. The mixture was reacted at room temperature for 3 hours, filtered, and the precipitate was dried to obtain NHS-activated ester-modified mica flakes. The total amount of EDC and NHS added was 35% of the mica flake mass. S1.3. The pretreated nano-magnetic powder and NHS-activated ester-modified mica flakes were mixed at a mass ratio of 2.8:1 to obtain a mixture. The mixture was placed in a phosphate buffer solution with a pH of 7.4 and dispersed evenly. After reacting at room temperature for 3 hours, the mixture was filtered, dried, and the precipitate was obtained to obtain the NHS-activated ester-modified mica flake-modified nano-magnetic powder composite.

[0024] In the following embodiments, the bottom layer and the release layer are made of the same isocyanate-modified fluorocarbon resin; the isocyanate-modified fluorocarbon resin is prepared from diisocyanate (isophorone diisocyanate), fluorocarbon resin (FEVE type fluorocarbon resin) and modified acrylic monomer in a molar ratio of 2:1:1; wherein the modified acrylic monomer is prepared by mixing thiol (β-mercaptoethanol) with acrylic monomer (isobornyl acrylate) and photoinitiator (2,2-dimethoxy-2-phenylacetophenone) under inert gas protection and carrying out a mercapto-vinyl click reaction at room temperature to obtain hydroxyl-terminated modified acrylic monomer; wherein the molar ratio of β-mercaptoethanol to isobornyl acrylate is 1:1, and the photoinitiator content is 1.5% of the total mass of isobornyl acrylate.

[0025] In the following embodiments, the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were prepared by the following method: 100 mL of deionized water was taken, sodium dodecyl sulfate (0.3% of the mass of deionized water) was added, and after stirring to dissolve, 15 mL of butyl acrylate, 5 mL of methyl methacrylate, and 8 g of N-isopropylacrylamide were added, stirred evenly, and ultrasonically dispersed for 10 min (ultrasonic power 200 W) to form a uniform emulsion system; nitrogen gas was introduced into the emulsion system to remove oxygen, and then ammonium persulfate was added, the amount of ammonium persulfate being 0.5% of the total mass of butyl acrylate, methyl methacrylate, and N-isopropylacrylamide. The temperature was raised to 70 °C, and the reaction was carried out at a constant temperature with stirring for 18 h. After filtration, washing, and drying, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were obtained.

[0026] In the following examples, the ethylene-vinyl alcohol copolymer is obtained by copolymerizing ethylene and vinyl alcohol in a mass ratio of 2.8:7.2.

[0027] In the following embodiments, the bottom layer is prepared by the following method: ethylene-vinyl alcohol copolymer is dissolved in an organic solvent (dimethyl sulfoxide) to obtain an ethylene-vinyl alcohol copolymer solution; isocyanate-modified fluorocarbon resin and n-butyl acetate are uniformly mixed, and then the ethylene-vinyl alcohol copolymer solution is added under stirring. After uniform mixing, dibutyl phthalate, polycarboxylate dispersant, 3-isocyanate-based propyltrimethoxysilane, and NHS activated ester modified mica flake modified nano-magnetic powder composite are added sequentially under stirring. After uniform stirring, the mixture is dispersed at high speed (1200-1500 r / min) to obtain the bottom layer slurry; the slurry is uniformly coated on a clean and dry magnetic plate surface and cured (completely cured at 60-70℃) to obtain the bottom layer.

[0028] In the following embodiments, the release layer is prepared by the following method: isocyanate-modified fluorocarbon resin and acrylate polyol are mixed in a dry container, and after uniform mixing, a silane coupling agent is added and the mixture is stirred until uniform. Then, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are slowly added at a stirring speed of 200-300 r / min. After the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are added and uniformly dispersed, a mixed adhesive solution is obtained. The mixed adhesive solution is vacuum degassed and then uniformly coated onto a release film. It is then completely cured at 50°C and cooled to 20°C to obtain the release layer. In use, the side of the release layer that is different from the release film is pressed and adhered to the bottom layer to bond the release layer to the magnetic plate surface. When it is necessary to peel off the release layer, the release layer is heated to about 40°C to reduce the adhesion strength between the release layer and the magnetic plate surface. After peeling off, it has relatively strong adhesion again at a low temperature (20°C) and can be reused.

[0029] In the following embodiments, the thickness of the bottom layer is 0.03-0.05 mm.

[0030] In the following embodiments, the thickness of the release layer is 0.45-0.55 mm (including the thickness of the release film).

[0031] Example 1

[0032] Based on the above, this invention provides a protective layer for an installation-free magnetic lamp in an oilfield. The protective layer is attached to the magnetic suction plate of the lamp, and multiple evenly distributed magnets are mounted on the magnetic suction plate. These magnets are neodymium iron boron magnets, and the static attraction force of a single magnet is greater than 20 kg (22 kg in this application). Figure 1 As shown, this embodiment of the installation-free magnetic lamp includes an adsorption upper plate 1 and a mounting plate 2. The adsorption upper plate 1 has openings, and magnet sleeves 3 are correspondingly placed at the opening positions. Magnets 4 are installed in the magnet sleeves 3 for adsorption. The mounting plate 2 is installed on the adsorption upper plate 1 by fixing screws. A lamp holder or a lamp can be directly installed on the mounting plate 2. The mounting plate has hanging rings for easy detachment. The magnets are located at the four corners of the square adsorption upper plate, arranged symmetrically. The magnetic plate surface is the surface of the adsorption upper plate 1 used for adsorption with the iron-based carrier, as shown... Figure 2 As shown; The protective layer includes a base layer and a release layer. The base layer is fully coated on the magnetic suction plate surface of the installation-free magnetic lamp. The release layer covers the base layer and the area of ​​the release layer is larger than the area of ​​the magnetic suction plate surface. The thickness of the base layer is 0.04 mm. The thickness of the release layer is 0.5 mm. The bottom layer comprises the following components in parts by weight: 48 parts isocyanate-modified fluorocarbon resin, 22 parts NHS activated ester modified mica flake modified nano-magnetic powder composite, 10 parts ethylene-vinyl alcohol copolymer, 15 parts n-butyl acetate, 3 parts dibutyl phthalate, 2 parts polycarboxylate dispersant, and 4 parts 3-isocyanate-propyltrimethoxysilane; the polycarboxylate dispersant actually uses DS8637 comb-structured polycarboxylate nano-dispersant. The release layer comprises the following components in parts by weight: 42 parts isocyanate-modified fluorocarbon resin, 34 parts acrylate polyol, 10 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 2 parts silane coupling agent (KH550 silane coupling agent is used).

[0033] The bottom layer is prepared by the following method: ethylene-vinyl alcohol copolymer is dissolved in dimethyl sulfoxide to obtain an ethylene-vinyl alcohol copolymer solution; isocyanate-modified fluorocarbon resin and n-butyl acetate are uniformly mixed, and then the ethylene-vinyl alcohol copolymer solution is added under stirring. After mixing evenly, dibutyl phthalate, polycarboxylate dispersant, 3-isocyanate-based propyltrimethoxysilane, and NHS activated ester modified mica flake modified nano-magnetic powder composite are added sequentially under stirring. After stirring evenly, the mixture is dispersed at high speed (1200-1500 r / min) to obtain the bottom layer slurry; the slurry is uniformly coated on a clean and dry magnetic plate surface and completely cured at 65°C to obtain the bottom layer.

[0034] The release layer is prepared by the following method: isocyanate-modified fluorocarbon resin and acrylate polyol are mixed in a dry container, and after uniform mixing, a silane coupling agent is added and the mixture is stirred until uniform. Then, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are slowly added at a stirring speed of 200 r / min. After the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are added and uniformly dispersed, a mixed adhesive solution is obtained. The mixed adhesive solution is vacuum degassed and then uniformly coated onto a release film. It is then completely cured at 50°C. After complete curing, it is cooled to 20°C to obtain the release layer. In use, the side of the release layer that is different from the release film is pressed and adhered to the bottom layer to bond the release layer to the magnetic plate surface. When it is necessary to peel off the release layer, the release layer is heated to about 40°C to reduce the adhesion strength between the release layer and the magnetic plate surface. After the release layer is peeled off, it has relatively strong adhesion again at a low temperature (20°C) and can be reused.

[0035] When the magnetic lamp in this application is not in use or for illumination, the release layer is attached to the outside of the bottom layer, and the release layer and the bottom layer work together to provide double protection for the magnetic plate surface.

[0036] Example 2

[0037] This embodiment differs from Embodiment 1 in that the underlying layer in this embodiment comprises the following components in parts by weight: 52 parts isocyanate-modified fluorocarbon resin, 25 parts NHS activated ester-modified mica flake-modified nanomagnetic powder composite, 11 parts ethylene-vinyl alcohol copolymer, 16.5 parts n-butyl acetate, 4 parts dibutyl phthalate, 2.5 parts polycarboxylate dispersant, and 4.5 parts 3-isocyanate-based propyltrimethoxysilane; the polycarboxylate dispersant actually used is DS8637 comb-structured polycarboxylate nanodispersant. The release layer comprises the following components in parts by weight: 45 parts isocyanate-modified fluorocarbon resin, 35 parts acrylate polyol, 11 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 2.5 parts silane coupling agent (KH550 silane coupling agent is used). The remaining components are the same as in Example 1.

[0038] Example 3

[0039] This embodiment differs from Embodiment 1 in that the underlying layer in this embodiment comprises the following components in parts by weight: 55 parts isocyanate-modified fluorocarbon resin, 28 parts NHS activated ester modified mica flake modified nano-magnetic powder composite, 12 parts ethylene-vinyl alcohol copolymer, 18 parts n-butyl acetate, 5 parts dibutyl phthalate, 3 parts polycarboxylate dispersant, and 5 parts 3-isocyanate-propyltrimethoxysilane; the polycarboxylate dispersant actually used is DS8637 comb-structured polycarboxylate nano-dispersant. The release layer comprises the following components in parts by weight: 48 parts isocyanate-modified fluorocarbon resin, 36 parts acrylate polyol, 12 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 3 parts silane coupling agent (KH550 silane coupling agent is used). The remaining components are the same as in Example 1.

[0040] Example 4

[0041] This embodiment differs from Embodiment 1 in that the thickness of the bottom layer is 0.03 mm, and the thickness of the release layer is 0.45 mm (including the thickness of the release film); all other aspects are the same.

[0042] Example 5

[0043] This embodiment differs from Embodiment 1 in that the thickness of the bottom layer is 0.05 mm, and the thickness of the release layer is 0.55 mm (including the thickness of the release film); all other aspects are the same.

[0044] Comparative Example 1 Based on Example 1, such as Figure 1 , Figure 2As shown in the comparative example, this installation-free magnetic lamp holder includes an upper adsorption plate 1 and a mounting plate 2. The upper adsorption plate 1 has an opening, and a magnet sleeve 3 is correspondingly placed at the opening position. A magnet 4 is installed in the magnet sleeve 3 for adsorption. The mounting plate 2 is mounted on the upper adsorption plate 1 by fixing screws 201. A lamp holder or a lamp can be directly mounted on the mounting plate 2. The magnets are neodymium iron boron magnets, with a single static attractive force greater than 20 kg. The magnetic surface of the upper adsorption plate 1 is as follows... Figure 2 As shown, neodymium iron boron magnets are exposed. No protective layer is attached to the surface of the magnetic accumulator.

[0045] Comparative Example 2 Based on Example 1, the difference from Example 1 is that the protective layer in this comparative example does not include the peeling layer, but only the bottom layer; the rest are the same.

[0046] Comparative Example 3 Based on Example 1, the difference from Example 1 is that the bottom layer of this comparative example does not contain NHS activated ester modified mica flake modified nano magnetic powder composite, while the rest are the same.

[0047] Comparative Example 4 Based on Example 1, the difference from Example 1 is that the bottom layer of this comparative example uses unmodified nano-magnetic powder instead of the NHS activated ester modified mica flake modified nano-magnetic powder composite in Example 1; the nano-magnetic powder in this comparative example is composed of nano-carbonyl iron powder and nano-ferric oxide magnetic powder, with a mass ratio of nano-carbonyl iron powder to nano-ferric oxide magnetic powder of 3:2.2; the particle size of nano-carbonyl iron powder is 60-80 nm, and the particle size of nano-ferric oxide magnetic powder is 50-70 nm; the rest are the same.

[0048] Comparative Example 5 Based on Example 1, but differing from Example 1, the mica flakes in the bottom layer of this comparative example are not modified with NHS-activated ester, but are directly compounded with nano-magnetic powder, replacing the NHS-activated ester-modified mica flake-modified nano-magnetic powder composite in Example 1. The preparation method is as follows: the nano-magnetic powder is composed of nano-carbonyl iron powder and nano-ferric oxide magnetic powder, with a mass ratio of nano-carbonyl iron powder to nano-ferric oxide magnetic powder of 3:2.2; the particle size of nano-carbonyl iron powder is 60-80 nm, and the particle size of nano-ferric oxide magnetic powder is 50-70 nm; the nano-magnetic powder and mica flakes are physically blended at a mass ratio of 2.8:1 to obtain a mixture; the mixture replaces the NHS-activated ester-modified mica flake-modified nano-magnetic powder composite in Example 1. The rest are the same.

[0049] Comparative Example 6 Based on Example 1, the difference from Example 1 is that the release layer of this comparative example does not contain poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, while the rest are the same.

[0050] Comparative Example 7 Based on Example 1, the difference from Example 1 is that the pressure-sensitive adhesive microspheres in this comparative release layer are not modified with poly-N-isopropylacrylamide. Based on the preparation method of Example 1, N-isopropylacrylamide is not added in the preparation of pressure-sensitive adhesive microspheres, and the other parameters are adjusted adaptively; the rest are the same.

[0051] Experimental Example 1 The magnetic attraction between the magnetic lamp adsorption plate and the iron-based carrier in Examples 1-5 (without a peeling layer, only the bottom layer), Comparative Examples 3-5 (without a peeling layer, only the bottom layer), and Comparative Example 1, as well as the oil resistance and rust resistance of the magnetic lamp adsorption surface, were tested. The results are shown in Table 1. Magnetic adhesion strength test: The magnetic lamps in each embodiment / comparative example are completely adsorbed onto the surface of a clean, flat Q235 steel plate (the steel plate is fixed, square, 300mm on each side, and 10mm thick) through the magnetic suction plate. The surface area of ​​the steel plate is larger than the magnetic suction plate surface area of ​​the magnetic lamp adsorption plate (square, 200mm on each side, and 10mm thick). A digital push-pull force gauge (range 500N, accuracy 0.1N) is used to act perpendicularly on the magnetic lamp (the digital push-pull force gauge hooks onto the lifting ring of the magnetic lamp mounting plate) and pull it at a constant speed (about 5 mm / s). The maximum pulling force value (separation force F) at the moment when the magnetic lamp separates from the steel plate is recorded. The larger the separation force (F), the better the magnetic adhesion strength. Oil stain resistance test: Only the magnetic lamp adsorption plate is used as the test sample (an independent part separated from the magnetic lamp), and the following items are tested: (1) Determine the oleophobic contact angle of the magnetic plate surface of the magnetic lamp adsorption plate (according to the existing measurement method, detect the oleophobic contact angle of hexadecane in the NdFeB magnet region); (2) Before applying oil stains, weigh the sample to obtain the initial weight M0; prepare simulated oilfield oil stains (crude oil: diesel = 3:1, mass ratio), apply evenly to the magnetic plate surface of each sample with a brush, the coating thickness is 0.5mm, place in a constant temperature environment of 25℃ for 24h, weigh the sample to obtain the weight M1, calculate the oil stain weight, and the oil stain weight M 油 =M1-M0; Wipe the magnetic sample three times with the same force using anhydrous ethanol cotton pads, weigh the treated sample, and obtain the treated weight M2. Calculate the oil residue amount. Oil residue rate = (M2-M0) / M 油 ×100%, the lower the oil residue rate, the better the oil resistance. Rust resistance test: Only the magnetic lamp adsorption plate is used as the test object (the independent part separated from the magnetic lamp is used as the sample). The sample (magnetic plate side up) is placed in the salt spray test chamber and a neutral salt spray test (NSS) is carried out in accordance with GB / T 10125-2021. After spraying continuously for 48 hours, the sample is taken out, rinsed with deionized water and dried, and the rust condition of the magnetic plate surface (magnet area) is observed.

[0052] Table 1 Performance test results of the magnetic accelerator plate Example 1 451±1 ＞100° 1.9±0.1% No rust present Example 2 465±1 ＞100° 1.5±0.1% No rust present Example 3 458±1 ＞100° 1.6±0.1% No rust present Example 4 460±1 ＞100° 2.2±0.1% No rust present Example 5 453±1 ＞100° 1.5±0.1% No rust present Comparative Example 1 471±1N ＜90° 18.6±0.1% Significant corrosion, with a corrosion area exceeding 20%. Comparative Example 3 312±1N ＞100° 4.3±0.1% No rust present Comparative Example 4 368±1N ＞100° 3.2±0.1% No rust present Comparative Example 5 352±1N ＞100° 3.5±0.1% No rust present Compared to the magnetic lamp in Comparative Document 1 (without protection), this application improves the oil and rust resistance of the magnetic plate surface while reducing the impact of the substrate on the magnetic attraction. The magnetic strength (separation force) of the magnetic plate surface after the substrate is attached in this application is less than 5% lower than that without the substrate (Comparative Example 1), and it still has good magnetic attraction in actual use. If the NHS activated ester modified mica flake modified nano magnetic powder composite is not added to the substrate, the magnetic strength is reduced by more than 30% compared to Comparative Example 1, and the magnetic attraction is prone to be weak during use.

[0053] Experimental Example 2 Based on the sample size of Test Example 1, only the magnetic lamp adsorption plate was used as the test sample (an independent part separated from the magnetic lamp). The magnetic attraction of the magnetic lamp magnetic surface to the iron filings in Examples 1-5 (containing the peeling layer), Comparative Examples 6 and 7 (containing the peeling layer), and Comparative Example 1, as well as the peel strength between the peeling layer and the magnetic lamp magnetic surface containing the coating, were tested. The results are shown in Table 2.

[0054] Magnetic attraction test of the magnetic plate surface of the adhesive peeling layer on iron filings: The magnetic surface of the sample is placed face down on top of a container containing standard iron filings (particle size 100-200 mesh) (the distance between the peeling layer and the top layer of iron filings is 1 cm). After standing for 10 minutes, it is taken out and the adhesion of iron filings on the magnetic surface (peeling layer) is observed. Peel strength test between the release layer and the magnetic surface of the magnetic lamp containing the underlying layer: Refer to GB / T 2792-2014, and perform a 90° peel test using a universal testing machine. After bonding the release layer to the corresponding underlying sample, place it in the testing machine and peel at 25℃ (release layer temperature) and 40℃ (release layer temperature) at a speed of 300 mm / min. Record the average peel force during the stable peeling stage.

[0055] Table 2 Performance testing of the release layer Example 1 No visible iron filings adhered to the surface. 1.6~1.7 0.4~0.5 Example 2 No visible iron filings adhered to the surface 1.8~1.9 0.4~0.5 Example 3 No visible iron filings adhered to the surface. 1.8~1.9 0.4~0.5 Example 4 No visible iron filings adhered to the surface 1.6~1.7 0.4~0.5 Example 5 No visible iron filings adhered to the surface 1.8~1.9 0.4~0.5 Comparative Example 6 No visible iron filings adhered to the surface 0.3~0.4 0.3~0.4 Comparative Example 7 No visible iron filings adhered to the surface. 1.2~1.3 1.2~1.3 The poly-N-isopropylacrylamide modified pressure-sensitive adhesive microspheres in this application, on the one hand, can improve the peel strength of the release layer and enhance its adhesiveness; on the other hand, it has temperature sensitivity. After the peel strength is improved, in order to facilitate peeling, the peel strength is reduced under heating due to its temperature sensitivity, which facilitates complete peeling and reuse.

[0056] Experimental Example 3 Based on the sample from Experiment Example 2, the peel strength of the peeling layer in Examples 1-5 was tested after repeated use a certain number of times. The results are shown in Table 3. The testing method was as follows: the same peeling layer was subjected to a cycle of "adhesion (room temperature 25℃) → heating and peeling (40℃) → cooling (placed at 20℃ for 10 minutes) → re-adhesion" with the magnetic plate surface of the sample containing the bottom layer in the corresponding embodiment / comparative example. After the 10th cycle, the peel strength was measured at 25℃ (room temperature) (refer to the test method of test example 2).

[0057] Table 3 Performance test of the number of cycles of the peeling layer Example 1 1.4~1.5 Example 2 1.7~1.8 Example 3 1.6~1.7 (not reaching 1.7) Example 4 1.5~1.6 Example 5 1.6~1.7 After 10 cycles, the adhesion (peel strength) of this application can reach more than 90% compared with the initial peel strength (25°C), and this application can be repeatedly used more than 10 times.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A protective layer for an installation-free magnetic lamp in an oilfield, the protective layer being attached to the magnetic suction plate of the installation-free magnetic lamp, wherein multiple evenly distributed magnets are mounted on the magnetic suction plate, the magnets being neodymium iron boron magnets, and the static attraction force of a single magnet being greater than 20 kg, characterized in that: The protective layer includes a base layer and a release layer. The base layer is fully coated on the magnetic suction plate surface of the magnetic lamp that does not require installation. The release layer covers the base layer and the area of ​​the release layer is larger than the area of ​​the magnetic suction plate surface. The bottom layer comprises the following components in parts by weight: 48-55 parts isocyanate-modified fluorocarbon resin, 22-28 parts NHS activated ester modified mica flake modified nano-magnetic powder composite, 10-12 parts ethylene-vinyl alcohol copolymer, 15-18 parts n-butyl acetate, 3-5 parts dibutyl phthalate, 2-3 parts polycarboxylate dispersant, and 4-5 parts 3-isocyanate-propyltrimethoxysilane; The release layer comprises the following components in parts by weight: 42-48 parts isocyanate-modified fluorocarbon resin, 34-36 parts acrylate polyol, 10-12 parts poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres, and 2-3 parts silane coupling agent. The bottom layer and the release layer are made of the same isocyanate-modified fluorocarbon resin. The isocyanate-modified fluorocarbon resin is prepared from isophorone diisocyanate, FEVE-type fluorocarbon resin and modified acrylic monomer in a molar ratio of 2:1:

1. The modified acrylic monomer is obtained by mixing β-mercaptoethanol with isobornyl acrylate and photoinitiator 2,2-dimethoxy-2-phenylacetophenone under inert gas protection and carrying out a mercapto-vinyl click reaction at room temperature to obtain hydroxyl-terminated modified acrylic monomer. The molar ratio of β-mercaptoethanol to isobornyl acrylate is 1:

1.

2. The protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The nano-magnetic powder is composed of nano-carbonyl iron powder and nano-ferric oxide magnetic powder, with a mass ratio of nano-carbonyl iron powder to nano-ferric oxide magnetic powder of 3:(2~2.5); the particle size of nano-carbonyl iron powder is 60-80nm, and the particle size of nano-ferric oxide magnetic powder is 50-70nm.

3. The protective layer for installation-free magnetic lamps in oilfields according to claim 2, characterized in that: The NHS-activated ester-modified mica flake-modified nano-magnetic powder composite was prepared by the following method: S1.1, nano carbonyl iron powder, and nano iron oxide magnetic powder are mixed evenly to obtain nano magnetic powder. The nano magnetic powder is added to an ethanol aqueous solution with a volume ratio of 3:1 and ultrasonically dispersed to obtain a nano magnetic powder suspension. Add 5% (by weight) of 3-aminopropyltriethoxysilane to the nano-magnetic powder suspension, heat to 60°C, react for 2-2.5 hours under stirring, filter, and dry to obtain pretreated nano-magnetic powder. S1.2 Add mica flakes to dichloromethane at a solid-liquid ratio of 1g:10ml. After stirring evenly, add succinic anhydride at 9% of the mass of the mica flakes. Heat to 70℃, stir at a constant temperature for 3 hours, and then filter to obtain modified mica flakes. Modified mica flakes were added to MES buffer solution at pH 6 and dispersed evenly. Then, EDC and NHS were added in a molar ratio of 1:(1.3~1.5). The mixture was reacted at room temperature for 3 hours, filtered, and the precipitate was dried to obtain NHS-activated ester modified mica flakes. S1.

3. The pretreated nano-magnetic powder and NHS activated ester modified mica flakes were mixed at a mass ratio of (2.7~2.9):1 to obtain a mixture. The mixture was placed in a phosphate buffer solution with a pH of 7.3-7.5, and after being dispersed evenly, it was reacted at room temperature for 2-3 hours. The mixture was then filtered, dried, and the precipitate was dried to obtain the NHS activated ester modified mica flake modified nano-magnetic powder composite.

4. The protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were prepared by the following method: Deionized water was taken, and sodium dodecyl sulfate was added at a concentration of 0.3% of the deionized water mass. After stirring and dissolving, butyl acrylate, methyl methacrylate, and N-isopropylacrylamide were added, stirred evenly, and ultrasonically dispersed for 10 min to form a uniform emulsion system. Nitrogen gas was introduced into the emulsion system to remove oxygen. Then, ammonium persulfate was added at a concentration of 0.5% of the total mass of butyl acrylate, methyl methacrylate, and N-isopropylacrylamide. The temperature was raised to 70℃, and the reaction was carried out under constant temperature stirring for 16-18 h. After filtration, washing, and drying, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres were obtained.

5. A protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The ethylene-vinyl alcohol copolymer is obtained by copolymerizing ethylene and vinyl alcohol in a mass ratio of 2.8:(7~7.3).

6. The protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The bottom layer is prepared by the following method: ethylene-vinyl alcohol copolymer is dissolved in an organic solvent to obtain an ethylene-vinyl alcohol copolymer solution; isocyanate-modified fluorocarbon resin and n-butyl acetate are uniformly mixed, and then the ethylene-vinyl alcohol copolymer solution is added under stirring. After mixing evenly, dibutyl phthalate, polycarboxylate dispersant, 3-isocyanate-based propyltrimethoxysilane, and NHS activated ester modified mica flake modified nano-magnetic powder composite are added sequentially under stirring. After stirring evenly, the mixture is dispersed at high speed to obtain the bottom layer slurry; the slurry is uniformly coated on a clean and dry magnetic plate surface and cured to obtain the bottom layer.

7. A protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The release layer is prepared by the following method: isocyanate-modified fluorocarbon resin and acrylate polyol are mixed in a dry container, and after uniform mixing, a silane coupling agent is added and the mixture is stirred until uniform. Then, poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are slowly added at a stirring speed of 200-300 r / min. After the poly(N-isopropylacrylamide) modified pressure-sensitive adhesive microspheres are added and uniformly dispersed, a mixed adhesive solution is obtained. The mixed adhesive solution is vacuum degassed and then uniformly coated onto a release film. It is then completely cured at 45-55℃. After complete curing, it is cooled to 20℃ to obtain the release layer. In use, the side of the release layer that is different from the release film is pressed and adhered to the bottom layer to bond the release layer to the magnetic plate surface.

8. A protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The thickness of the bottom layer is 0.03-0.05 mm.

9. A protective layer for installation-free magnetic lamps in oilfields according to claim 1, characterized in that: The thickness of the peeling layer is 0.45-0.55 mm.

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