A magnetic material coating stripping agent and its preparation and application methods

Abstract

This invention proposes a magnetic material coating stripping agent and its preparation and application methods, belonging to the technical field of stripping agents. It includes an aqueous solution and a powder. The aqueous solution is prepared from the following raw materials in parts by weight: 5-15 parts sodium phosphate, 0.5-2 parts sodium benzoate, 1-5 parts glycerol, 0.5-2 parts tributyl phosphate, 0.1-1 parts water-soluble defoamer BYK022, and 75-90 parts water. The powder is prepared from the following raw materials in parts by weight: 3-5 parts modified photocatalytic degradation agent, and 4-6 parts acid-loaded porous nano-calcium carbonate. This magnetic material coating stripping agent exhibits good coating stripping effect, acting more quickly and effectively between the coating layer and the magnetic substrate, reducing peel strength. It is virtually non-corrosive to the magnetic substrate material, easy to store and transport, has a long service life, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of stripping agent technology, specifically to a magnetic material coating stripping agent and its preparation and application methods. Background Technology

[0002] Magnetic materials are a class of materials that can respond to magnetic fields in a certain way. Based on the strength of their magnetism in an external magnetic field, they can be classified into diamagnetic, paramagnetic, ferromagnetic, antiferromagnetic, and ferrimagnetic materials. Most materials are diamagnetic or paramagnetic, and their response to external magnetic fields is relatively weak. Ferromagnetic and ferrimagnetic materials are strongly magnetic materials; the term "magnetic material" usually refers to strongly magnetic materials. For magnetic materials, magnetization curves and hysteresis loops are characteristic curves reflecting their fundamental magnetic properties. Ferromagnetic materials are generally composed of Fe, Co, Ni elements and their alloys, rare earth elements and their alloys, and some Mn compounds. Magnetic materials are generally classified into soft magnetic materials and hard magnetic materials according to their ease of magnetization.

[0003] Due to the long-term use and durability of magnetic materials, coating treatment is often applied. Firstly, corrosion prevention is a crucial reason for coating. Magnetic materials in their raw form, especially neodymium magnets, are highly susceptible to corrosion. When exposed to water or humid environments, neodymium magnets undergo a transformation from Nd to Nd(OH)3, leading to volume increase and degradation of magnetic properties. Electroplating or coating effectively prevents this corrosion, protecting the stability of the magnetic material in various environments. Secondly, protecting the magnetism is another purpose of coating. Coating helps maintain the intended magnetic field in extreme temperatures or when exposed to liquids or vapors, preventing the magnetic field from weakening due to external environmental influences. Furthermore, preventing physical damage is another important reason. Magnetic materials are easily subjected to impacts or friction during transportation or use, leading to breakage, peeling, or other physical damage.

[0004] Coating can provide a protective layer, reducing the occurrence of such damage. However, improper substrate surface treatment, such as the presence of oxides, grease, or other contaminants, can affect the adhesion between the coating and the substrate, leading to difficulty in coating peeling. Secondly, inappropriate selection of coating materials can also cause problems. For example, epoxy resins and polyurethanes have good adhesion and chemical resistance, making them suitable for coating magnetic materials. However, some materials, such as polyethylene, are prone to peeling. Finally, issues with the coating process can also lead to difficulties in coating peeling. Improper control of process parameters during coating can also result in difficult coating peeling.

[0005] Korean Patent Publication No. 2001-0018377 discloses a photoresist stripper comprising an amine compound, a glycol solvent, and a perfluoroalkyl ethylene oxide.

[0006] Korean Patent Publication No. 2000-0016878 discloses a stripping solution composed of an alkoxy-N-hydroxyalkyl chain alkanoamide, a polar substance with a dipole moment of 3 or more, a damage prevention agent, and an alkanolamine.

[0007] However, the stripping agents proposed by existing technologies are used under high-temperature process conditions, which is detrimental in terms of environment and processing costs, and also has limitations in terms of removing washing residues. Moreover, due to the high-temperature process conditions, there is an inherent risk of corrosion, which may cause corrosion of the magnetic materials and affect its effectiveness. Summary of the Invention

[0008] The purpose of this invention is to provide a magnetic material coating stripping agent and its preparation and application methods. It has a good coating stripping effect, can act more quickly and effectively between the coating layer and the magnetic material substrate, reduce the peeling strength, and has almost no corrosiveness to the magnetic substrate material. It is also easy to store, convenient to transport, has a long service life, and has broad application prospects.

[0009] The technical solution of this invention is implemented as follows:

[0010] This invention provides a magnetic material coating stripping agent, comprising an aqueous solution and a powder. The aqueous solution is prepared from the following raw materials in parts by weight: 5-15 parts sodium phosphate, 0.5-2 parts sodium benzoate, 1-5 parts glycerol, 0.5-2 parts tributyl phosphate, 0.1-1 parts water-soluble defoamer BYK022, and 75-90 parts water. The powder is prepared from the following raw materials in parts by weight: 3-5 parts modified photocatalytic degradation agent and 4-6 parts acid-loaded porous nano-calcium carbonate.

[0011] As a further improvement of the present invention, the preparation method of the modified photocatalytic degradation agent is as follows:

[0012] S1. Preparation of porous nano-titanium dioxide: Tetrabutyl titanate was dissolved in ethanol, water and a pore-forming agent were added, the pH value was adjusted, the reaction was heated and stirred, centrifuged, washed, dried and calcined to prepare porous nano-titanium dioxide.

[0013] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: Citric acid, thiourea and sodium molybdate were mixed and dissolved in water, the pH value was adjusted with hydrochloric acid, glutathione and porous nano titanium dioxide were added, the mixture was subjected to hydrothermal reaction, dialyzed, and the unpermeated liquid was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide.

[0014] S3. Preparation of modified photocatalytic degradation agent: Add graphene / MoS2 quantum dot modified titanium dioxide to PBS buffer, add EDC and NHS, stir to activate, add 2-aminobenzoic acid and zirconium tetrachloride DMF solution, perform hydrothermal reaction, centrifuge, wash, dry to obtain modified photocatalytic degradation agent.

[0015] As a further improvement of the present invention, the mass ratio of tetrabutyl titanate, ethanol, water and porogen in step S1 is 3-5:40-50:5-10:0.5-1, the porogen is hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide, the pH value is adjusted to 5-6, the temperature of the heating and stirring reaction is 45-55℃, and the time is 4-6h.

[0016] As a further improvement of the present invention, the mass ratio of citric acid, thiourea, sodium molybdate, glutathione and porous nano-titanium dioxide in step S2 is 3-5:0.5-1:4-6:6-9:12-15, the pH value is adjusted to 6-6.5, the hydrothermal reaction temperature is 190-210℃, and the time is 10-14h.

[0017] As a further improvement of the present invention, the PBS buffer in step S3 has a pH value of 7-7.4, the mass ratio of the doped graphene / MoS2 quantum dot modified titanium dioxide, EDC, NHS, 2-aminobenzoic acid and zirconium tetrachloride is 13-15:2-3:2-3:3-5:4-6, the hydrothermal reaction temperature is 120-130℃, and the time is 20-24h.

[0018] As a further improvement of the present invention, the preparation method of the acid-loaded porous nano-calcium carbonate is as follows:

[0019] T1. Add pore-forming agent, emulsifier and calcium salt to water to prepare a solution; add the solution dropwise to ethyl acetate, emulsify, add carbonate solution dropwise, stir to react, let stand, centrifuge, wash and dry to obtain porous calcium carbonate nanopowder;

[0020] T2. Citric acid and porous calcium carbonate nanoparticles are ball-milled and mixed evenly to obtain acid-loaded porous calcium carbonate nanoparticles.

[0021] As a further improvement of the present invention, the mass ratio of the porogen, emulsifier, calcium salt and carbonate in step T1 is 0.1-0.2:0.5-1:5-7:10-15, the porogen is polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80 and Tween-85, the stirring reaction time is 10-20 min, the carbonate is sodium carbonate or potassium carbonate, and the calcium salt is calcium chloride, calcium sulfate or calcium nitrate.

[0022] As a further improvement of the present invention, the mass ratio of citric acid to porous calcium carbonate nanopowder in step T2 is 3-5:10-12, and the ball milling time is 2-4 hours.

[0023] This invention further protects a method for preparing the above-mentioned magnetic material coating stripping agent, comprising the following steps:

[0024] (1) Add sodium phosphate to water, heat to 40-50℃ and stir to dissolve, cool to 25-30℃ and add sodium benzoate, continue stirring until completely dissolved, add tributyl phosphate and water-soluble defoamer BYK-022 in sequence, stir slowly, add glycerin, remove undissolved impurities through a filter screen or filter paper to obtain an aqueous solution;

[0025] (2) Mix the modified photocatalytic degradation agent and acid-loaded porous nano calcium carbonate evenly to obtain a powder.

[0026] The present invention further protects a method of using the above-mentioned magnetic material coating stripper, wherein the powder is evenly applied to the surface of the coating and a water-based agent is sprayed.

[0027] The present invention has the following beneficial effects:

[0028] The magnetic material coating stripping agent of this invention uses a chemical + physical + photocatalytic degradation stripping method to remove the magnetic material coating, and includes an aqueous solution and a powder:

[0029] In this aqueous solution, sodium phosphate hydrolyzes in water to generate phosphate and hydroxide ions with very low dissociation, softening hard water. It can form soluble complexes with metal ions such as calcium and magnesium in the water, thus reducing water hardness and preventing metal ions from reacting with other components in the coating stripper to form insoluble substances, which would affect the performance and effectiveness of the stripper. Simultaneously, it significantly promotes the dispersion and emulsification of dirt particles, allowing grease and dirt in the coating to be better dispersed in water and subsequently detached from the substrate surface. Furthermore, sodium phosphate is highly alkaline, capable of converting fatty dirt into water-soluble soap through saponification, enhancing the coating stripper's ability to remove greasy coatings. It also regulates and maintains the pH of the coating stripper system, providing a suitable alkaline environment for other components to exert their synergistic effects.

[0030] Sodium benzoate can inhibit the growth and reproduction of microorganisms, prevent coating strippers from deteriorating, becoming moldy, or developing an off-flavor during storage and use, and extend their shelf life and service life.

[0031] Glycerin possesses excellent hygroscopic and moisturizing properties, enabling the coating release agent to maintain a certain level of humidity during use, preventing it from drying out too quickly. This prolongs the interaction time between the release agent and the coating, facilitating full expansion and peeling of the coating. It can improve the spreadability and leveling properties of the coating release agent, allowing it to be applied more evenly to the surface of the coating to be peeled, forming a continuous liquid film and enhancing the peeling effect. Glycerin also acts as a solvent and coupling agent, dissolving and penetrating with other components in the coating release agent, enhancing the synergistic effect between the components. Simultaneously, it helps reduce the viscosity of the coating release agent, improving its flowability and processing performance, facilitating production and use.

[0032] Tributyl phosphate is an organophosphate compound with good solvent and penetrating properties. It can penetrate into the coating, disrupting the chemical bonds and physical adsorption between the coating and the substrate, causing the coating to loosen and peel off. It can interact with resins, pigments, and other components in the coating, dissolving or swelling the organic components, reducing the coating's adhesion and strength, thus achieving effective peeling. Furthermore, tributyl phosphate also possesses a certain degree of stability and low toxicity, which can improve the safety and environmental friendliness of coating release agents to some extent.

[0033] During the application of coating release agents, stirring and mixing can easily generate foam, affecting the application performance and effectiveness of the release agent. Water-soluble defoamer BYK022 can quickly eliminate and inhibit foam generation, preventing excessive foam from causing release agent overflow and uneven coating peeling, ensuring that the release agent can uniformly contact and react with the coating. It has good water solubility and compatibility, effectively exerting its defoaming effect without affecting other properties of the coating release agent, and without causing harm to the environment or human health.

[0034] The powder includes a modified photocatalytic degradation agent and acid-loaded porous nano-calcium carbonate. The acid-loaded porous nano-calcium carbonate is formed by ball milling solid citric acid onto the surface of porous nano-calcium carbonate. When the acid-loaded porous nano-calcium carbonate is coated onto the surface of the coating, and an aqueous solution is sprayed, the citric acid dissolves in the water and immediately reacts with the calcium carbonate. Under the coordinated action of other components of the aqueous solution, the powder and citric acid penetrate through the coating and react to produce a large amount of carbon dioxide gas. The force of the carbon dioxide escaping into the air causes the coating to desorb from the substrate, thereby improving the peelability of the coating and achieving the purpose of peeling the coating.

[0035] The modified photocatalytic degradation agent uses porous nano-titanium dioxide as the core, with in-situ loaded graphene quantum dots and MoS2 quantum dots doped with S and N elements. The presence of C=S bonds in the S and N co-doped graphene quantum dots can broaden the absorption range of visible light. After being combined with titanium dioxide, the visible light absorption of the composite material is also enhanced, thus enabling more effective utilization of the visible light portion of solar energy. The combination of MoS2 quantum dots and titanium dioxide can form a heterojunction. The energy level matching between the two can effectively separate photogenerated electron-hole pairs, reduce the recombination probability of photogenerated carriers, and thus improve photocatalytic performance. Then, NiO-66-NH2 metal-organic framework material is coupled to the surface of the graphene / MoS2 quantum dot modified titanium dioxide. Under ultraviolet light irradiation, its Zr-oxo clusters and organic ligands absorb photon energy, causing electrons to jump from the valence band to the conduction band, forming photogenerated electron-hole pairs. Its unique structure helps reduce electron-hole recombination. For example, Zr groups can serve as electron enrichment sites, while organic ligands can easily enrich holes, thereby achieving effective separation of photogenerated carriers. It has a high specific surface area and abundant pore structure, which helps increase the contact opportunities between reactant molecules and active sites, promotes the diffusion and transport of substances, and thus improves the efficiency of photocatalytic reactions.

[0036] The magnetic material coating stripper of this invention has a good coating stripping effect, can act more quickly and effectively between the coating layer and the magnetic material substrate, reduce the peeling strength, and has almost no corrosiveness to the magnetic substrate material. It is also easy to store, convenient to transport, has a long service life, and has broad application prospects. Detailed Implementation

[0037] 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.

[0038] Preparation Example 1: Preparation of Modified Photocatalytic Degrader

[0039] The method is as follows:

[0040] S1. Preparation of porous nano-titanium dioxide: 3g tetrabutyl titanate was dissolved in 40g ethanol, 5g water and 0.5g hexadecyltrimethylammonium chloride were added, the pH was adjusted to 5, heated to 45℃, stirred for 4h, centrifuged, washed, dried, and calcined at 500℃ for 2h to prepare porous nano-titanium dioxide.

[0041] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: 3g citric acid, 0.5g thiourea and 4g sodium molybdate were mixed and dissolved in 200mL water. The pH was adjusted to 6 with hydrochloric acid. 6g glutathione and 12g porous nano-titanium dioxide were added. The mixture was hydrothermally reacted at 190℃ for 10h. Dialysis was performed using a 3000Da dialysis bag for 12h. The unpermeable liquid was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide.

[0042] S3. Preparation of modified photocatalytic degradation agent: 13g of graphene / MoS2 quantum dot modified titanium dioxide was added to 200mL of PBS buffer with pH 7, 2g of EDC and 2g of NHS were added, and the mixture was stirred and activated for 30min. Then, 200mL of DMF solution containing 3g of 2-aminobenzoic acid and 4g of zirconium tetrachloride was added, and the mixture was hydrothermally reacted at 120℃ for 20h. After centrifugation, washing and drying, the modified photocatalytic degradation agent was obtained.

[0043] Preparation Example 2: Preparation of Modified Photocatalytic Degrader

[0044] The method is as follows:

[0045] S1. Preparation of porous nano-titanium dioxide: 5g tetrabutyl titanate was dissolved in 50g ethanol, 10g water and 1g hexadecyltrimethylammonium bromide were added, the pH was adjusted to 6, heated to 55℃, stirred for 6h, centrifuged, washed, dried, and calcined at 500℃ for 2h to obtain porous nano-titanium dioxide.

[0046] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: 5g citric acid, 1g thiourea and 6g sodium molybdate were mixed and dissolved in 200mL water. The pH was adjusted to 6.5 with hydrochloric acid. 9g glutathione and 15g porous nano titanium dioxide were added. The mixture was hydrothermally reacted at 210℃ for 14h. Dialysis was performed using a 3000Da dialysis bag for 12h. The unpermeable liquid was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide.

[0047] S3. Preparation of modified photocatalytic degradation agent: 15g of graphene / MoS2 quantum dot modified titanium dioxide was added to 200mL of PBS buffer with pH 7.4, 3g of EDC and 3g of NHS were added, and the mixture was stirred and activated for 30min. Then, 200mL of DMF solution containing 5g of 2-aminobenzoic acid and 6g of zirconium tetrachloride was added, and the mixture was hydrothermally reacted at 130℃ for 24h. After centrifugation, washing and drying, the modified photocatalytic degradation agent was obtained.

[0048] Preparation Example 3: Preparation of Modified Photocatalytic Degrader

[0049] The method is as follows:

[0050] S1. Preparation of porous nano-titanium dioxide: 4g tetrabutyl titanate was dissolved in 45g ethanol, 7g water and 0.7g cetyltrimethylammonium bromide were added, the pH was adjusted to 5.5, heated to 50℃, stirred for 5h, centrifuged, washed, dried and calcined at 500℃ for 2h to obtain porous nano-titanium dioxide.

[0051] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: 4g citric acid, 0.7g thiourea and 5g sodium molybdate were mixed and dissolved in 200mL water. The pH was adjusted to 6.2 with hydrochloric acid. 7.5g glutathione and 13g porous nano titanium dioxide were added. The mixture was hydrothermally reacted at 200℃ for 12h. Dialysis was performed using a 3000Da dialysis bag for 12h. The unpermeable liquid was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide.

[0052] S3. Preparation of modified photocatalytic degradation agent: 14g of graphene / MoS2 quantum dot modified titanium dioxide was added to 200mL of PBS buffer with pH 7.2, along with 2.5g of EDC and 2.5g of NHS. The mixture was stirred and activated for 30min. Then, 200mL of DMF solution containing 4g of 2-aminobenzoic acid and 5g of zirconium tetrachloride was added. The mixture was subjected to hydrothermal reaction at 125℃ for 22h. After centrifugation, washing, and drying, the modified photocatalytic degradation agent was obtained.

[0053] Comparative Preparation Example 1

[0054] The difference from Preparation Example 3 is that thiourea was not added in step S2.

[0055] Specifically as follows:

[0056] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: 4g citric acid and 5g sodium molybdate were mixed and dissolved in 200mL water. The pH was adjusted to 6.2 with hydrochloric acid. 7.5g glutathione and 13g porous nano titanium dioxide were added. The mixture was hydrothermally reacted at 200℃ for 12h. Dialysis was performed using a 3000Da dialysis bag for 12h. The impurity was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide.

[0057] Comparative Preparation Example 2

[0058] The difference from Preparation Example 3 is that citric acid was not added in step S2.

[0059] Specifically as follows:

[0060] S2. Preparation of MoS2 quantum dot modified titanium dioxide: 0.7g thiourea and 9g sodium molybdate were mixed and dissolved in 200mL of water. The pH was adjusted to 6.2 with hydrochloric acid. 7.5g glutathione and 13g porous nano titanium dioxide were added. The mixture was hydrothermally reacted at 200℃ for 12h. The mixture was dialyzed using a 3000Da dialysis bag for 12h. The unpermeable liquid was freeze-dried to obtain MoS2 quantum dot modified titanium dioxide.

[0061] Comparative preparation example 3

[0062] The difference from Preparation Example 3 is that sodium molybdate was not added in step S2.

[0063] Specifically as follows:

[0064] S2. Preparation of graphene quantum dot-modified titanium dioxide: 9g citric acid and 0.7g thiourea were mixed and dissolved in 200mL water. The pH was adjusted to 6.2 with hydrochloric acid. 7.5g glutathione and 13g porous nano-titanium dioxide were added. The mixture was subjected to hydrothermal reaction at 200℃ for 12h. Dialysis was performed using a 3000Da dialysis bag for 12h. The unpermeable liquid was freeze-dried to obtain graphene quantum dot-modified titanium dioxide.

[0065] Comparative preparation example 4

[0066] The difference from preparation example 3 is that step S2 was not performed.

[0067] Specifically as follows:

[0068] S1. Preparation of porous nano-titanium dioxide: 4g tetrabutyl titanate was dissolved in 45g ethanol, 7g water and 0.7g cetyltrimethylammonium bromide were added, the pH was adjusted to 5.5, heated to 50℃, stirred for 5h, centrifuged, washed, dried and calcined at 500℃ for 2h to obtain porous nano-titanium dioxide.

[0069] S2. Preparation of modified photocatalytic degradation agent: 14g of porous nano-titanium dioxide was added to 200mL of PBS buffer with pH 7.2, and 200mL of DMF solution containing 4g of 2-aminobenzoic acid and 5g of zirconium tetrachloride was added. The mixture was hydrothermally reacted at 125℃ for 22h, centrifuged, washed, and dried to obtain the modified photocatalytic degradation agent.

[0070] Comparative preparation example 5

[0071] The difference from preparation example 3 is that step S3 was not performed.

[0072] Specifically as follows:

[0073] S1. Preparation of porous nano-titanium dioxide: 4g tetrabutyl titanate was dissolved in 45g ethanol, 7g water and 0.7g cetyltrimethylammonium bromide were added, the pH was adjusted to 5.5, heated to 50℃, stirred for 5h, centrifuged, washed, dried and calcined at 500℃ for 2h to obtain porous nano-titanium dioxide.

[0074] S2. Preparation of graphene / MoS2 quantum dot modified titanium dioxide: 4g citric acid, 0.7g thiourea, and 5g sodium molybdate were mixed and dissolved in 200mL of water. The pH was adjusted to 6.2 with hydrochloric acid. 7.5g glutathione and 13g porous nano-titanium dioxide were added. The mixture was subjected to hydrothermal reaction at 200℃ for 12h. Dialysis was performed using a 3000Da dialysis bag for 12h. The impurity was freeze-dried to obtain graphene / MoS2 quantum dot modified titanium dioxide, which is the modified photocatalytic degradation agent.

[0075] Test Example 1: Purification Effect on Antibiotic Wastewater

[0076] Configuration 10 -3 The cephalexin solution was prepared as antibiotic wastewater. The pH of the wastewater containing polymers was adjusted to 7 using 0.1 mol / L hydrochloric acid and 0.01 mol / L sodium hydroxide. 50 mL of cephalexin solution was taken, and 10 mg of the modified photocatalytic degradation agent prepared in Preparation Examples 1-3 and Comparative Preparation Examples 1-5 was added respectively. The mixture was stirred at 300 rpm for 10 min under visible light irradiation to ensure thorough mixing with the wastewater, followed by sedimentation for 60 min. The supernatant was collected and centrifuged at 10000 rpm for 10 min. The absorption peak at 262 nm was detected using a UV-Vis spectrophotometer, and the removal effect on cephalexin was calculated. The results are shown in Table 1.

[0077] Table 1

[0078] Group Cephalexin clearance rate (%) Preparation Example 1 94.4 Preparation Example 2 95.2 Preparation Example 3 95.5 Comparative Preparation Example 1 88.9 Comparative Preparation Example 2 84.5 Comparative preparation example 3 85.2 Comparative preparation example 4 77.5 Comparative preparation example 5 83.2

[0079] As shown in the table above, the modified photocatalytic degraders prepared in Examples 1-3 of this invention have good photocatalytic degradation effects on antibiotic wastewater.

[0080] Preparation Example 4: Preparation of Acid-Loaded Porous Nanoscale Calcium Carbonate

[0081] The method is as follows:

[0082] T1. 0.1 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123, 0.5 g of Tween-40 and 5 g of calcium chloride were added to 150 mL of water to prepare a solution; the solution was added dropwise to 250 mL of ethyl acetate, emulsified at 8000 r / min for 15 min, 100 mL of aqueous solution containing 10 g of sodium carbonate was added dropwise, the mixture was stirred for 10 min, allowed to stand for 12 h, centrifuged, washed and dried to obtain porous calcium carbonate nanopowder;

[0083] T2. Mix 3g of citric acid with 10g of porous calcium carbonate nanopowder evenly, and ball mill for 2 hours to obtain acid-loaded porous nano-calcium carbonate.

[0084] Preparation Example 5: Preparation of Acid-Loaded Porous Nanoscale Calcium Carbonate

[0085] The method is as follows:

[0086] T1. 0.2 g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123, 1 g of Tween-20 and 7 g of calcium sulfate were added to 150 mL of water to prepare a solution; the solution was added dropwise to 250 mL of ethyl acetate, emulsified at 8000 r / min for 15 min, 100 mL of aqueous solution containing 15 g of potassium carbonate was added dropwise, the mixture was stirred for 20 min, allowed to stand for 12 h, centrifuged, washed and dried to obtain porous calcium carbonate nanopowder;

[0087] T2. Mix 5g of citric acid with 12g of porous calcium carbonate nanopowder evenly, and ball mill for 2-4 hours to obtain acid-loaded porous nano-calcium carbonate.

[0088] Preparation Example 6: Preparation of Acid-Loaded Porous Nanoscale Calcium Carbonate

[0089] The method is as follows:

[0090] T1. 0.15g of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123, 0.7gt Tween-85 and 6g of calcium nitrate were added to 150mL of water to prepare a solution; the solution was added dropwise to 250mL of ethyl acetate, emulsified at 8000r / min for 15min, 100mL of aqueous solution containing 12g of sodium carbonate was added dropwise, the reaction was stirred for 15min, allowed to stand for 12h, centrifuged, washed and dried to obtain porous calcium carbonate nanopowder;

[0091] T2. Mix 4g of citric acid with 11g of porous calcium carbonate nanoparticles evenly and ball mill for 3 hours to obtain acid-loaded porous nano-calcium carbonate.

[0092] Example 1

[0093] This embodiment provides a magnetic material coating stripper, comprising an aqueous solution and a powder, with a mass ratio of 20:3;

[0094] The aqueous solution is prepared from the following raw materials in parts by weight: 5 parts sodium phosphate, 0.5 parts sodium benzoate, 1 part glycerin, 0.5 parts tributyl phosphate, 0.1 parts water-soluble defoamer BYK022 and 75 parts water.

[0095] The powder is prepared from the following raw materials in parts by weight: 3 parts of the modified photocatalytic degradation agent obtained in Preparation Example 1, and 4 parts of the acid-loaded porous nano-calcium carbonate obtained in Preparation Example 4.

[0096] The preparation method includes the following steps:

[0097] (1) Add sodium phosphate to water, heat to 40°C and stir to dissolve, cool to 25°C and add sodium benzoate, continue stirring until completely dissolved, add tributyl phosphate and water-soluble defoamer BYK-022 in sequence, stir slowly, add glycerin, remove undissolved impurities through a filter screen or filter paper to obtain an aqueous solution;

[0098] (2) Mix the modified photocatalytic degradation agent and acid-loaded porous nano calcium carbonate evenly to obtain a powder.

[0099] Example 2

[0100] This embodiment provides a magnetic material coating stripper, comprising an aqueous solution and a powder, with a mass ratio of 20:3;

[0101] The aqueous solution is prepared from the following raw materials in parts by weight: 15 parts sodium phosphate, 2 parts sodium benzoate, 5 parts glycerin, 2 parts tributyl phosphate, 1 part water-soluble defoamer BYK022, and 90 parts water.

[0102] The powder is prepared from the following raw materials in parts by weight: 5 parts of the modified photocatalytic degradation agent obtained in Preparation Example 2, and 6 parts of the acid-loaded porous nano-calcium carbonate obtained in Preparation Example 5.

[0103] The preparation method includes the following steps:

[0104] (1) Add sodium phosphate to water, heat to 50°C and stir to dissolve, cool to 30°C and add sodium benzoate, continue stirring until completely dissolved, add tributyl phosphate and water-soluble defoamer BYK-022 in sequence, stir slowly, add glycerin, remove undissolved impurities through a filter screen or filter paper to obtain an aqueous solution;

[0105] (2) Mix the modified photocatalytic degradation agent and acid-loaded porous nano calcium carbonate evenly to obtain a powder.

[0106] Example 3

[0107] This embodiment provides a magnetic material coating stripper, comprising an aqueous solution and a powder, with a mass ratio of 20:3;

[0108] The aqueous solution is prepared from the following raw materials in parts by weight: 10 parts sodium phosphate, 1 part sodium benzoate, 3 parts glycerin, 1 part tributyl phosphate, 0.5 parts water-soluble defoamer BYK022 and 82 parts water.

[0109] The powder is prepared from the following raw materials in parts by weight: 4 parts of the modified photocatalytic degradation agent obtained in Preparation Example 3, and 5 parts of the acid-loaded porous nano-calcium carbonate obtained in Preparation Example 6.

[0110] The preparation method includes the following steps:

[0111] (1) Add sodium phosphate to water, heat to 45°C and stir to dissolve, cool to 27°C and add sodium benzoate, continue stirring until completely dissolved, add tributyl phosphate and water-soluble defoamer BYK-022 in sequence, stir slowly, add glycerin, remove undissolved impurities through a filter screen or filter paper to obtain an aqueous solution;

[0112] (2) Mix the modified photocatalytic degradation agent and acid-loaded porous nano calcium carbonate evenly to obtain a powder.

[0113] Comparative Example 1

[0114] The difference from Example 3 is that the modified photocatalytic degrader was prepared from Comparative Preparation Example 1.

[0115] Comparative Example 2

[0116] The difference from Example 3 is that the modified photocatalytic degrader was prepared from Comparative Preparation Example 2.

[0117] Comparative Example 3

[0118] The difference from Example 3 is that the modified photocatalytic degradation agent was prepared from Comparative Preparation Example 3.

[0119] Comparative Example 4

[0120] The difference from Example 3 is that the modified photocatalytic degradation agent was prepared from Comparative Preparation Example 4.

[0121] Comparative Example 5

[0122] The difference from Example 3 is that the modified photocatalytic degrader was prepared from Comparative Preparation Example 5.

[0123] Comparative Example 6

[0124] The difference compared to Example 3 is that no modified photocatalytic degradation agent was added.

[0125] Comparative Example 7

[0126] The difference compared to Example 3 is that no acid-loaded porous nano-calcium carbonate was added.

[0127] Test Example 2

[0128] Referring to the national standard GB / T 2790-1995 "Test Method for 180° Peel Strength of Adhesives - Flexible Materials vs. Rigid Materials", epoxy resin coating NPES-901 (Kunshan Nanya) was applied to a magnet. After curing, the magnetic material coating release agent prepared in Examples 1-3 or Comparative Examples 1-7, including water and powder in a mass ratio of 20:3, was used for treatment. The method was to evenly apply the powder to the surface of the coating, spray the water, and then conduct a 180° peel strength test.

[0129] First, the width of the magnet and the average thickness of the coating were tested. The unbonded portion of the coating was bent 180° and clamped onto the base fixture of the universal testing machine. The exposed magnet portion was clamped onto the machine's crossbeam fixture, ensuring the entire sample was vertical. The separation speed of the two clamps was 50 mm / min. After the test, a peel force curve was obtained. An estimated contour line was drawn to obtain the average peel force, and the average peel strength value was calculated. Five samples of each type were tested, and the average value was obtained. The results are shown in Table 2.

[0130] Table 2

[0131]

[0132]

[0133] As can be seen from the table above, the magnetic material coating stripping agent prepared in Examples 1-3 of the present invention can easily peel off the coating layer on the surface of the magnet.

[0134] Test Example 3

[0135] Clean the magnet sheet with acetone to remove oil stains, soak it in anhydrous ethanol for 1 minute, dry it, weigh and record the initial mass of the sample. Pour the aqueous solution of the magnetic material coating stripping agent prepared in Examples 1-3 of this invention into the reaction vessel for later use. Place the treated sample on the plate holder, turn on the power of the high temperature and high pressure dynamic corrosion instrument, adjust the pressure of the reaction vessel to 12 MPa at 100°C, and the stirring speed to 50 r / min to ensure that the entire surface of the sample is in contact with the aqueous solution. After reacting for 4 hours, turn off the power, quickly remove the sample, rinse it with clean water, brush it with a soft brush, and finally wash the sample with acetone and anhydrous ethanol, dry it, and weigh the sample. Calculate the corrosion rate of the sample using the formula: v i - Corrosion rate of the test piece, g / (m²) 2 ·h); Δt - reaction time, h; Δm i - Sample mass loss, g; A i - Surface area of ​​the test piece, mm 2 The results are shown in Table 3.

[0136]

[0137] Table 3

[0138] Group <![CDATA[Corrosion rate (g·(m 2 ·h) -1 )]]> Example 1 0.0005 Example 2 0.0003 Example 3 0.0002

[0139] As can be seen from the table above, the aqueous solution of the magnetic material coating stripper prepared in Examples 1-3 of this invention has very little corrosiveness to the magnet sheet.

[0140] 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 magnetic material coating layer peeling agent characterized by comprising: The water agent is prepared from the following raw materials by weight: sodium phosphate 5-15 parts, sodium benzoate 0.5-2 parts, glycerol 1-5 parts, tributyl phosphate 0.5-2 parts, water-soluble defoaming agent BYK022 0.1-1 part and water 75-90 parts; the powder is prepared from the following raw materials by weight: modified photocatalytic degrading agent 3-5 parts, acid-carrying porous nano calcium carbonate 4-6 parts; the preparation method of the modified photocatalytic degrading agent is as follows: S1. Preparation of porous nano titanium dioxide: tetrabutyl titanate is dissolved in ethanol, water and a pore former are added, the pH value is adjusted, heating and stirring reaction, centrifugation, washing, drying, calcination, and porous nano titanium dioxide is prepared; S2. Preparation of doped graphene / MoS2 quantum dot modified titanium dioxide: citric acid, thiourea and sodium molybdate are mixed in water, the pH value is adjusted with hydrochloric acid, glutathione and porous nano titanium dioxide are added, mixed hydrothermal reaction, dialysis, freeze-drying of the non-permeate, and doped graphene / MoS2 quantum dot modified titanium dioxide is prepared; S3. Preparation of modified photocatalytic degrading agent: doped graphene / MoS2 quantum dot modified titanium dioxide is added to PBS buffer solution, EDC and NHS are added, stirring activation, 2-aminobenzoic acid and zirconium tetrachloride DMF solution are added, hydrothermal reaction, centrifugation, washing, drying, and modified photocatalytic degrading agent is prepared.

2. The magnetic material coating layer stripper according to claim 1, characterized by, The mass ratio of tetrabutyl titanate, ethanol, water and pore former in step S1 is 3-5:40-50:5-10:0.5-1, the pore former is cetyltrimethylammonium chloride or cetyltrimethylammonium bromide, the pH value is adjusted to 5-6, the heating and stirring reaction temperature is 45-55℃, and the time is 4-6h.

3. The magnetic material coating layer stripper according to claim 1, characterized by, The mass ratio of citric acid, thiourea, sodium molybdate, glutathione and porous nano titanium dioxide in step S2 is 3-5:0.5-1:4-6:6-9:12-15, the pH value is adjusted to 6-6.5, the hydrothermal reaction temperature is 190-210℃, and the time is 10-14h.

4. The magnetic material coating layer stripper according to claim 1, characterized by, The PBS buffer solution in step S3 has a pH value of 7-7.4, and the mass ratio of doped graphene / MoS2 quantum dot modified titanium dioxide, EDC, NHS, 2-aminobenzoic acid and zirconium tetrachloride is 13-15:2-3:2-3:3-5:4-6, the hydrothermal reaction temperature is 120-130℃, and the time is 20-24h.

5. The magnetic material coating layer stripper according to claim 1, wherein The preparation method of the acid-carrying porous nano calcium carbonate is as follows: T1. A pore former, an emulsifier and a calcium salt are added to water to prepare a solution; the solution is added dropwise to ethyl acetate, emulsified, a carbonate solution is added dropwise, stirred and reacted, allowed to stand, centrifuged, washed, and dried to obtain porous calcium carbonate nano powder; T2. Citric acid is mixed uniformly with the porous calcium carbonate nano powder by ball milling to obtain acid-carrying porous nano calcium carbonate.

6. The magnetic material coating layer stripper according to claim 5, wherein The mass ratio of the pore forming agent, emulsifier, calcium salt and carbonate in step T1 is 0.1-0.2:0.5-1:5-7:10-15, the pore forming agent is polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123, the emulsifier is at least one selected from Tween-20, Tween-40, Tween-60, Tween-80, Tween-85, the stirring reaction time is 10-20 min, the carbonate is sodium carbonate or potassium carbonate, and the calcium salt is calcium chloride, calcium sulfate or calcium nitrate.

7. The magnetic material coating layer stripper according to claim 5, wherein The mass ratio of the citric acid to the porous calcium carbonate nanopowder in step T2 is 3-5:10-12, and the ball milling time is 2-4 h.

8. A method for producing the magnetic material coating layer stripper according to any one of claims 1 to 7, characterized by, The method comprises the following steps: Sodium phosphate is added to water, heated to 40-50°C and stirred to dissolve, cooled to 25-30°C, sodium benzoate is added, and stirring is continued until complete dissolution, tributyl phosphate and water-soluble defoaming agent BYK-022 are added in sequence, slowly stirred, glycerol is added, and the undissolved impurities are removed through a filter screen or filter paper to obtain an aqueous agent; The modified photocatalytic degrading agent and the acid-carrying porous nano calcium carbonate are uniformly mixed to obtain a powder.

9. A method for using the magnetic material coating layer peeling agent according to any one of claims 1 to 7, characterized by, The powder is uniformly applied to the surface of the coating layer, and the aqueous agent is sprayed.

Images