Ultrathin strong magnetic sheet, preparation method thereof and application of ultrathin strong magnetic sheet in eyelash ornament

Abstract

The invention belongs to the technical field of magnetic complexes, and particularly relates to an ultrathin strong magnetic sheet, a preparation method thereof and application of the ultrathin strong magnetic sheet in eyelash ornaments. The ultrathin strong magnetic sheet comprises the following raw materials in parts by weight: 85-90 parts of magnetic powder, 5-10 parts of a composite binder and 2-6 parts of a coupling agent, the magnetic powder is selected from any one of ferrite magnetic powder, samarium iron nitrogen magnetic powder, samarium cobalt magnetic powder and neodymium iron boron magnetic powder. The ultrathin strong magnetic sheet provided by the invention can realize excellent magnetic induction intensity stability, damp heat resistance and salt fog resistance when the thickness is 0.1 mm, and has a good application prospect in eyelash ornaments.

Description

Technical Field

[0001] This invention belongs to the field of magnetic composite technology, specifically relating to an ultrathin strong magnetic sheet, its preparation method, and its application in eyelash ornaments. Background Technology

[0002] Traditional false eyelashes are fixed with chemical glue, which has a complex composition and often contains irritating substances such as acrylate copolymers and formaldehyde. They are uncomfortable to wear, can easily cause allergies, and can even cause the original eyelashes to fall out.

[0003] In recent years, magnetic false eyelashes have received widespread attention. They come in various forms, including flat eyelashes with magnetic elements used in combination with magnetic eyeliner, or false eyelashes with magnetic pieces embedded in the band, which hold the real eyelashes in place. Magnetic false eyelashes have the advantages of avoiding glue irritation and being reusable.

[0004] The magnetic sheet in magnetic false eyelashes directly affects their wearing effect and comfort. Hard magnetic sheets have high magnetism but lead to poor fit; soft magnetic sheets generally have low magnetism and are prone to falling off; thick soft magnetic sheets can cause pressure on the eyelids and poor comfort. To solve the above problems, the applicant's previous research results were disclosed in Chinese Patent No. CN111772280B, which discloses an eyelash accessory that is simple, quick, safe and reliable to wear, using an ultra-thin, strong, flexible neodymium iron boron magnetic sheet as a carrier. The neodymium iron boron magnetic sheet is composed of the following raw materials in the following weight percentages: neodymium iron boron powder: composite adhesive powder: other additives = (85-90): (7-9): (1-8), wherein the neodymium iron boron powder is grade MQ15-7, the composite adhesive powder is silicone rubber, and the additives are titanate coupling agents. However, in actual use, the applicant found that when placed in a high-temperature and high-humidity bathroom, the service life is reduced and rust spots appear.

[0005] Chinese Patent CN119742140B discloses an ultra-thin flexible magnetic eyelash magnet and its preparation method. Each set of eyelash magnets consists of two magnetic sheets, one upper and one lower, with opposing magnetic poles arranged on each sheet. The magnetism of the opposing magnetic poles exhibits a gradient distribution on the magnetic sheets, with stronger magnetism at the edges and weaker magnetism in the center. The raw materials of the magnetic sheets include samarium iron nitrogen magnetic powder and polypropylene. Samarium iron nitrogen is non-toxic and resistant to sweat corrosion, while polypropylene meets cosmetic-grade standards, improving biocompatibility and solving the problem of unreliability in traditional magnetic eyelash materials. The magnetic sheets are designed with an opposing magnetized structure, allowing for strong adsorption between the upper and lower magnetic sheets, overcoming the drawback of traditional magnetic eyelashes being prone to falling out. They can be folded more than 500 times without breaking, conform to the curvature of the eyes, and are comfortable to wear. However, the minimum thickness of the magnetic sheet in this technical solution is 0.14 mm, and its corrosion resistance needs improvement. Furthermore, this technical solution does not address high-temperature resistance. Summary of the Invention

[0006] In order to overcome the shortcomings of existing technologies, the present invention provides an ultrathin strong magnetic sheet, its preparation method and its application in eyelash ornaments.

[0007] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides an ultrathin strong magnetic sheet, comprising the following raw materials in parts by weight: 85-90 parts magnetic powder, 5-10 parts composite binder, and 2-6 parts coupling agent; The magnetic powder is selected from any one of ferrite magnetic powder, samarium iron nitrogen magnetic powder, samarium cobalt magnetic powder, and neodymium iron boron magnetic powder.

[0008] Furthermore, the ferrite magnetic powder is selected from barium ferrite magnetic powder and / or strontium ferrite magnetic powder.

[0009] Furthermore, the neodymium iron boron magnetic powder is rapidly quenched neodymium iron boron magnetic powder.

[0010] Furthermore, the magnetic powder is magnetic powder treated with a pretreatment agent; the pretreatment agent includes a carboxyl-terminated liquid nitrile rubber modified epoxy resin and an ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer.

[0011] This invention uses any one of ferrite magnetic powder, samarium iron nitrogen magnetic powder, samarium cobalt magnetic powder, and neodymium iron boron magnetic powder as the raw material for ultrathin strong magnetic sheets. The magnetic powder is pretreated with carboxyl liquid nitrile rubber modified epoxy resin and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer to form a coating on the surface of the magnetic powder. This improves the compatibility between the magnetic powder and the binder, enhances the stability of the magnetic induction intensity of the magnetic powder, and prevents the penetration of water vapor and corrosive media, thereby increasing the service life of the ultrathin strong magnetic sheet.

[0012] Furthermore, the mass ratio of the carboxyl-terminated liquid nitrile rubber modified epoxy resin and the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is 1-2:1-2.

[0013] Furthermore, the carboxyl-terminated liquid nitrile rubber modified epoxy resin is a carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and / or a carboxyl-terminated liquid nitrile rubber modified cyclohexyldimethyl diglycidyl ether.

[0014] Furthermore, the elastomer content of the terminal carboxyl group liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%.

[0015] Furthermore, the elastomer content of the terminal carboxyl group liquid nitrile rubber modified cyclohexyldiethanol diglycidyl ether is 20%.

[0016] Furthermore, the method for preparing magnetic powder treated with a pretreatment agent includes the following steps: Mix magnetic powder, pretreatment agent and organic solvent, ball mill, filter and dry after ball milling to obtain the final product.

[0017] Furthermore, the amount of the pretreatment agent used is 0.1-0.2 times the total mass of the magnetic powder.

[0018] Furthermore, the organic solvent is selected from at least one of ethyl acetate and acetone.

[0019] Furthermore, the amount of organic solvent used is 2-4 times the total mass of the magnetic powder.

[0020] Furthermore, the ball mill rotates at a speed of 600-800 r / min, the ball mill temperature is 30-50℃, and the ball milling time is 3-5 h.

[0021] Furthermore, the coupling agent is a titanate coupling agent.

[0022] Furthermore, the titanate coupling agent is selected from at least one of di(dioctylpyrophosphoryloxy)ethylene glycol titanate, isopropyltris(dioctylpyrophosphoryloxy)titanate, and di(octylpyrophosphoryl)hydroxyacetate titanate.

[0023] Furthermore, the composite binder includes silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder.

[0024] Improper selection of binder can lead to unstable magnetic induction intensity and decreased resistance to damp heat and salt spray. Through experimental research, the inventors discovered that using organosilicon rubber powder, epoxidized organosilicon elastomer powder, and nitrile rubber powder as a composite binder yields the best results. This may be because the binder components have good compatibility with the modified magnetic powder and can interact with each other, thereby obtaining an ultra-thin strong magnetic sheet with the magnetic powder and binder tightly integrated, which improves the stability of magnetic induction intensity, resistance to damp heat, and resistance to salt spray of the ultra-thin strong magnetic sheet.

[0025] Furthermore, the mass ratio of the silicone rubber powder, the epoxidized silicone elastomer powder, and the nitrile rubber powder is 10-20:2-5:1-3.

[0026] Furthermore, the mass ratio of the silicone rubber powder, the epoxidized silicone elastomer powder, and the nitrile rubber powder is 15:3:2.

[0027] Furthermore, the silicone rubber powder is selected from at least one of amorphous silicone rubber powder and spherical silicone rubber powder.

[0028] Furthermore, the average particle size of the amorphous silicone rubber powder is 25-35µm.

[0029] Furthermore, the particle size of the spherical silicone rubber powder is 5-15µm.

[0030] Furthermore, the acrylonitrile content of the nitrile rubber is 28-33%.

[0031] Furthermore, the thickness of the ultrathin strong magnetic sheet is 0.1-0.2 mm.

[0032] Furthermore, the magnetic induction intensity of the ultrathin strong magnetic sheet is greater than 700GS.

[0033] Secondly, the present invention provides a method for preparing an ultrathin strong magnetic sheet, comprising the following steps: The above raw materials are mixed evenly at high temperature according to the formula, and then rolled, cut and magnetized in sequence to obtain the final product.

[0034] Thirdly, the present invention provides an application of an ultrathin strong magnetic sheet in the preparation of eyelash ornaments.

[0035] Compared with the prior art, the present invention has the following beneficial effects: This invention uses any one of ferrite magnetic powder, samarium iron nitrogen magnetic powder, samarium cobalt magnetic powder, and neodymium iron boron magnetic powder as the raw material for ultrathin strong magnetic sheets. The magnetic powder is pretreated with carboxyl-modified nitrile rubber and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer. Silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder are used as composite binders. The resulting ultrathin strong magnetic sheet exhibits excellent magnetic induction strength stability (magnetic induction strength still above 700GS after 6 months at 25℃), resistance to damp heat (magnetic induction strength still above 700GS after 7 days at 60℃ and 90%RH, with no rust spots) and salt spray resistance (magnetic induction strength still above 700GS after 7 days of neutral salt spray, with no rust spots) at a thickness of 0.1mm. It can be used to prepare eyelash ornaments. Attached Figure Description

[0036] Figure 1 This is a photograph of the ultrathin strong magnetic sheet of Example 1 after being placed at 60°C and 90%RH for 7 days. Figure 2 The image shows the ultra-thin strong magnetic sheet of Comparative Example 1 after being placed at 60°C and 90%RH for 7 days. Figure 3 The image shows the ultra-thin strong magnetic sheet of Comparative Example 4 after being placed at 60°C and 90%RH for 7 days. Figure 4 This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 1 after 7 days of neutral salt spray testing. Figure 5 This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 2 after 7 days of neutral salt spray testing. Figure 6This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 4 after 7 days of neutral salt spray testing. Detailed Implementation

[0037] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0038] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.

[0039] Example 1

[0040] An ultrathin strong magnetic sheet is composed of the following raw materials in parts by weight: 85 parts of rapidly quenched NdFeB magnetic powder treated with a pretreatment agent, 5 parts of composite binder, and 3 parts of coupling agent.

[0041] The pretreatment agent is a carboxyl-terminated liquid butadiene-acrylonitrile rubber modified neopentyl glycol glycidyl ether.

[0042] The elastomer content of the terminal carboxyl group liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%, and it is sourced from Shenzhen Jiadida New Material Technology Co., Ltd., model: HyPox RM 20.

[0043] The method for preparing magnetic powder using a pretreatment agent includes the following steps: Rapidly quenched NdFeB magnetic powder, pretreatment agent and acetone are mixed and ball-milled at 700 r / min and 40℃ for 4 h. After ball milling, the mixture is filtered and dried to obtain the final product.

[0044] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0045] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0046] The composite adhesive is composed of silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder in a mass ratio of 15:3:2.

[0047] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0048] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0049] The nitrile rubber has an acrylonitrile content of 28%, is sourced from Ningbo Shunze Rubber Co., Ltd., and its model number is NBR2880.

[0050] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0051] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps: According to the formula, the above raw materials are mixed evenly at high temperature and then subjected to calendering, cutting and magnetization processes to obtain an ultra-thin strong magnetic sheet with a thickness of 0.1 mm.

[0052] Example 2

[0053] An ultrathin strong magnetic sheet is composed of the following raw materials in parts by weight: 85 parts of rapidly quenched NdFeB magnetic powder treated with a pretreatment agent, 5 parts of composite binder, and 3 parts of coupling agent.

[0054] The pretreatment agent is an ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer.

[0055] The ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is from Jiayou Chemical, model: BF-2B.

[0056] The method for preparing magnetic powder using a pretreatment agent includes the following steps: Rapidly quenched NdFeB magnetic powder, pretreatment agent and acetone are mixed and ball-milled at 700 r / min and 40℃ for 4 h. After ball milling, the mixture is filtered and dried to obtain the final product.

[0057] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0058] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0059] The composite adhesive is composed of silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder in a mass ratio of 15:3:2.

[0060] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0061] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0062] The nitrile rubber has an acrylonitrile content of 28%, is sourced from Ningbo Shunze Rubber Co., Ltd., and its model number is NBR2880.

[0063] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0064] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps: According to the formula, the above raw materials are mixed evenly at high temperature and then subjected to calendering, cutting and magnetization processes to obtain an ultra-thin strong magnetic sheet with a thickness of 0.1 mm.

[0065] Example 3

[0066] An ultrathin strong magnetic sheet is composed of the following raw materials in parts by weight: 85 parts of rapidly quenched NdFeB magnetic powder treated with a pretreatment agent, 5 parts of composite binder, and 3 parts of coupling agent.

[0067] The pretreatment agent is a 1:1 mass ratio of terminal carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer.

[0068] The elastomer content of the terminal carboxyl group liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%, and it is sourced from Shenzhen Jiadida New Material Technology Co., Ltd., model: HyPox RM 20.

[0069] The ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is from Jiayou Chemical, model: BF-2B.

[0070] The method for preparing magnetic powder using a pretreatment agent includes the following steps: Rapidly quenched NdFeB magnetic powder, pretreatment agent and acetone are mixed and ball-milled at 700 r / min and 40℃ for 4 h. After ball milling, the mixture is filtered and dried to obtain the final product.

[0071] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0072] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0073] The composite adhesive is composed of silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder in a mass ratio of 15:3:2.

[0074] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0075] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0076] The nitrile rubber has an acrylonitrile content of 28%, is sourced from Ningbo Shunze Rubber Co., Ltd., and its model number is NBR2880.

[0077] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0078] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps: According to the formula, the above raw materials are mixed evenly at high temperature and then subjected to calendering, cutting and magnetization processes to obtain an ultra-thin strong magnetic sheet with a thickness of 0.1 mm.

[0079] Example 4

[0080] The only difference from Example 3 is that the rapidly quenched NdFeB magnetic powder is replaced with an equal mass of barium ferrite magnetic powder; all other aspects are the same.

[0081] Example 5

[0082] The only difference from Example 3 is that the rapidly quenched NdFeB magnetic powder is replaced with an equal mass of Samarium Iron Nitrogen magnetic powder; all other aspects are the same.

[0083] Example 6

[0084] The only difference from Example 3 is that the rapidly quenched NdFeB magnetic powder is replaced with an equal mass of Samarium Cobalt magnetic powder; all other aspects are the same.

[0085] Comparative Example 1 The only difference from Example 3 is that the rapidly quenched NdFeB magnetic powder is not treated with a pretreatment agent; otherwise, they are the same.

[0086] Comparative Example 2 The only difference from Example 3 is that the epoxidized silicone elastomer powder is replaced with an equal mass of acrylate rubber powder; all other aspects are the same.

[0087] Comparative Example 3 The only difference from Example 3 is that the nitrile rubber powder is replaced with an equal mass of epoxidized silicone elastomer powder; all other aspects are the same.

[0088] Comparative Example 4 The only difference from Example 3 is that the silicone rubber powder is replaced with an equal mass of nitrile rubber powder; all other aspects are the same.

[0089] Comparative Example 5 The only difference from Example 3 is that the composite adhesive is a silicone composite powder (silicone rubber powder coated with silicone resin) and nitrile rubber powder with a mass ratio of 18:2. The particle size of the silicone composite powder is 30µm and it is derived from Shin-Etsu KMP-602; all other aspects are the same.

[0090] I. The following performance tests were conducted on Examples 1-6 and Comparative Examples 1-5. 1. Magnetic induction intensity: tested using a gaussmeter.

[0091] 2. Service life: (1) Placed at 25℃, the test period is 6 months, and the magnetic induction intensity is tested by a gaussmeter after the test.

[0092] (2) Placed at 60℃ and 90%RH for 7 days, observe whether rust spots appear. The results of Example 1 are as follows: Figure 1 As shown, the results of Comparative Example 1 are as follows: Figure 2 As shown, the results of Comparative Example 4 are as follows: Figure 3 As shown, its magnetic flux density was measured using a gaussmeter.

[0093] (3) The neutral salt spray test was conducted according to GB / T 10125-2021 standard. The test period was 7 days. Observe whether rust spots appear. The results of Comparative Example 1 are as follows: Figure 4 As shown, the results of Comparative Example 2 are as follows: Figure 5 As shown, the results of Comparative Example 4 are as follows: Figure 6 As shown, its magnetic flux density was measured using a gaussmeter.

[0094] Note: Magnetic induction intensity is tested at the edge of the sample.

[0095] II. Performance test results of Examples 1-6 and Comparative Examples 1-5 Table 1 Performance Test Results Testing items Magnetic flux density / GS Magnetic flux density / GS after 6 months at 25℃ Magnetic induction intensity / GS after 7 days at 60℃ and 90%RH Will rust spots appear after 7 days at 60℃ and 90%RH? Magnetic induction / GS intensity after 7 days of neutral salt spray Will rust spots appear after 7 days of neutral salt spray? Example 1 705 616 625 no 646 no Example 2 721 643 637 no 658 no Example 3 780 716 735 no 755 no Example 4 620 538 562 no 591 no Example 5 802 743 755 no 765 no Example 6 818 755 762 no 776 no Comparative Example 1 672 595 614 yes 632 yes Comparative Example 2 745 642 651 no 688 yes Comparative Example 3 763 685 701 no 725 no Comparative Example 4 742 655 668 yes 692 yes Comparative Example 5 720 615 628 no 650 no As can be seen from Table 1: Compared with Example 3: the rapid quenching NdFeB magnetic powder of Example 1 was treated only with neopentyl glycol glycidyl ether modified with terminal carboxyl-terminated liquid nitrile butadiene rubber; the rapid quenching NdFeB magnetic powder of Example 2 was treated only with ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer; the performance of the resulting ultrathin strong magnetic sheets could not reach that of Example 3, indicating that the neopentyl glycol glycidyl ether modified with terminal carboxyl-terminated liquid nitrile butadiene rubber and the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer have a synergistic effect; Example 4 uses barium ferrite magnetic powder, which reduces costs, but the performance of the resulting ultrathin strong magnetic sheet is not as good as that of rapidly quenched neodymium iron boron magnetic powder. Example 5 uses samarium iron nitrogen magnetic powder, and Example 6 uses samarium cobalt magnetic powder. The resulting ultrathin strong magnetic sheet is slightly better than that of rapidly quenched neodymium iron boron magnetic powder, but the cost is high. The rapidly quenched NdFeB magnetic powder of Comparative Example 1 was not treated with a pretreatment agent, resulting in a decrease in the magnetic induction intensity of the obtained ultrathin strong magnetic sheet, and rust spots appeared after the test at 60℃, 90%RH and neutral salt spray conditions.

[0096] The composition of the composite binder in Comparative Examples 2-5 changed, and the magnetic induction intensity of the resulting ultrathin strong magnetic sheets did not change much, but the long-term storage performance, resistance to damp heat and salt spray decreased.

[0097] III. The following performance tests were conducted on Example 3: Content of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, phthalates, hexabromocyclododecane, perfluorooctanoic acid, perfluorooctane sulfonic acid, and phthalates.

[0098] IV. Test Results of Example 3 Table 2 Performance Test Results

[0099] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An ultrathin strong magnetic sheet, characterized in that, The raw materials include the following parts by weight: 85-90 parts magnetic powder, 5-10 parts composite binder, and 2-6 parts coupling agent; The magnetic powder is selected from any one of ferrite magnetic powder, samarium iron nitrogen magnetic powder, samarium cobalt magnetic powder and neodymium iron boron magnetic powder; The magnetic powder is magnetic powder treated with a pretreatment agent; the pretreatment agent includes a carboxyl-terminated liquid nitrile rubber modified epoxy resin and an ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer. The composite binder includes silicone rubber powder, epoxidized silicone elastomer powder, and nitrile rubber powder.

2. The ultrathin strong magnetic sheet according to claim 1, characterized in that, The ferrite magnetic powder is selected from barium ferrite magnetic powder and / or strontium ferrite magnetic powder; the neodymium iron boron magnetic powder is rapidly quenched neodymium iron boron magnetic powder.

3. The ultrathin strong magnetic sheet according to claim 1, characterized in that, The carboxyl-terminated liquid nitrile rubber modified epoxy resin is a carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and / or a carboxyl-terminated liquid nitrile rubber modified cyclohexyldimethyl diglycidyl ether.

4. The ultrathin strong magnetic sheet according to claim 3, characterized in that, The elastomer content of the terminal carboxyl liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%; the elastomer content of the terminal carboxyl liquid nitrile rubber modified cyclohexyldiethanol diglycidyl ether is 20%.

5. The ultrathin strong magnetic sheet according to claim 4, characterized in that, The mass ratio of the end-carboxyl liquid nitrile rubber modified epoxy resin and the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is 1-2:1-2.

6. The ultrathin strong magnetic sheet according to claim 5, characterized in that, The method for preparing magnetic powder using a pretreatment agent includes the following steps: Mix magnetic powder, pretreatment agent and organic solvent, ball mill, filter and dry after ball milling to obtain the final product.

7. The ultrathin strong magnetic sheet according to claim 1, characterized in that, The mass ratio of the silicone rubber powder, the epoxidized silicone elastomer powder, and the nitrile rubber powder is 10-20:2-5:1-3.

8. The ultrathin strong magnetic sheet according to claim 1, characterized in that, The thickness of the ultrathin strong magnetic sheet is 0.1-0.2 mm; the magnetic induction intensity of the ultrathin strong magnetic sheet is greater than 700 GS.

9. The method for preparing the ultrathin strong magnetic sheet according to any one of claims 1-8, characterized in that, Includes the following steps: The above raw materials are mixed evenly at high temperature according to the formula, and then rolled, cut and magnetized in sequence to obtain the final product.

10. The use of the ultrathin strong magnetic sheet according to any one of claims 1-8 in the preparation of eyelash ornaments.

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