An ultrathin strong magnetic sheet, a preparation method thereof and application thereof in a mascara

Abstract

The application belongs to the technical field of magnetic composite, and particularly relates to an ultrathin strong magnetic sheet, a preparation method thereof and application thereof in a mascara accessory. The ultrathin strong magnetic sheet comprises the following raw materials in parts by weight: magnetic powder 85-90 parts, composite binder 5-10 parts and coupling agent 2-6 parts. 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 application can realize excellent magnetic induction intensity stability, moisture resistance, heat resistance and salt spray resistance at a thickness of 0.1 mm, and has a good application prospect in the mascara accessory.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic composites, and particularly relates to an ultrathin strong magnetic sheet, a preparation method thereof and application of the ultrathin strong magnetic sheet in a mascara. BACKGROUND

[0002] Traditional false eyelashes are fixed by chemical glue, and the glue contains complex components, such as acrylic ester copolymer and formaldehyde, which are irritating substances. Therefore, the wearing comfort is poor, and allergic problems are prone to occur, and even the original eyelashes are prone to falling off.

[0003] In recent years, magnetic false eyelashes have attracted widespread attention. The types of magnetic false eyelashes include sheet type eyelashes provided with magnetic elements and used in combination with magnetic eyeliner, or magnetic sheets embedded in the stems of false eyelashes, which are used to fix the real eyelashes by clamping the real eyelashes with the upper and lower magnetic sheets. The magnetic false eyelashes have the advantages of avoiding glue irritation and being reusable.

[0004] The magnetic sheet in the magnetic false eyelashes directly affects the wearing effect and comfort. A hard magnetic sheet has high magnetism, but causes poor fitting. A soft magnetic sheet generally has low magnetism, and is prone to falling off. A soft magnetic sheet with high thickness causes pressure on the eyelid, and poor comfort. To solve the above problems, the applicant's previous research results, a Chinese patent with the publication number CN111772280B, discloses a mascara with simple and fast wearing, safety and reliability, which takes an ultrathin strong magnetic flexible neodymium iron boron magnetic sheet as a carrier. The neodymium iron boron magnetic sheet is composed of the following raw materials in percentage by weight: neodymium iron boron powder: composite adhesive powder: other additives = (85-90): (7-9): (1-8). The neodymium iron boron powder is MQ15-7. The composite adhesive powder is silicone rubber. The additive is a titanate coupling agent. However, in the actual use process, the applicant finds that when placed in a bathroom with high temperature and high humidity, the service life is poor, and rust spots appear.

[0005] A Chinese patent with the publication number CN119742140B discloses an ultrathin flexible magnetic false eyelash magnetic sheet and a preparation method thereof. Each group of eyelash magnetic sheets is composed of two magnetic sheets. The two magnetic sheets are arranged with opposite magnetic poles, and the magnetism of the opposite magnetic poles is in a gradient distribution on the magnetic sheet, which is strong at the edge and weak in the middle. The raw materials of the magnetic sheet include samarium iron nitrogen magnetic powder and polypropylene. The samarium iron nitrogen magnetic powder is non-toxic and resistant to sweat corrosion. The polypropylene meets the cosmetic grade standard, and improves the biological safety. The problems of unreliable traditional magnetic false eyelashes are solved. The magnetic sheet is designed as a magnetized structure. The upper and lower two layers of magnetic sheets can achieve firm adsorption, and overcome the defect that the traditional magnetic false eyelashes are prone to falling off. The magnetic sheet does not break after being folded more than 500 times. The magnetic sheet fits the curvature of the eye, and the wearing is comfortable. However, the minimum thickness of the magnetic sheet is 0.14 mm, the corrosion resistance needs to be improved, and the technology does not pay attention to the high temperature resistance. SUMMARY

[0006] In order to overcome the deficiencies existing in the prior art, the present application provides an ultrathin strong magnetic sheet, a preparation method thereof and an application thereof in a mascara.

[0007] The technical scheme adopted by the present application is as follows:

[0008] In a first aspect, the present application provides an ultrathin strong magnetic sheet, which comprises the following raw materials by weight: 85-90 parts of magnetic powder, 5-10 parts of composite binder, and 2-6 parts of coupling agent.

[0009] 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.

[0010] Further, the ferrite magnetic powder is selected from barium ferrite magnetic powder and / or strontium ferrite magnetic powder.

[0011] Further, the neodymium-iron-boron magnetic powder is a rapidly quenched neodymium-iron-boron magnetic powder.

[0012] Further, the magnetic powder is a magnetic powder treated with a pretreatment agent; the pretreatment agent comprises carboxyl-terminated liquid nitrile rubber modified epoxy resin and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer.

[0013] The present application uses any one of ferrite magnetic powder, samarium-iron-nitrogen magnetic powder, samarium-cobalt magnetic powder, and neodymium-iron-boron magnetic powder as a raw material of the ultrathin strong magnetic sheet, and uses carboxyl-terminated liquid nitrile rubber modified epoxy resin and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer to pretreat the magnetic powder, so as to form a coating on the surface of the magnetic powder, improve the compatibility of the magnetic powder and the binder, improve the stability of the magnetic induction strength of the magnetic powder, prevent the penetration of water vapor and corrosive media, and further improve the service life of the ultrathin strong magnetic sheet.

[0014] Further, 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.

[0015] Further, the carboxyl-terminated liquid nitrile rubber modified epoxy resin is carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and / or carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether.

[0016] Further, the elastomer content of the carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%.

[0017] Further, the elastomer content of the carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether is 20%.

[0018] Further, the preparation method of the magnetic powder treated with the pretreatment agent comprises the following steps:

[0019] Mixing the magnetic powder, the pretreatment agent and the organic solvent, ball milling, filtering and drying after the ball milling to obtain the mixture.

[0020] Further, the amount of the pretreatment agent is 0.1-0.2 times of the total mass of the magnetic powder.

[0021] Further, the organic solvent is at least one selected from ethyl acetate and acetone.

[0022] Further, the amount of the organic solvent is 2-4 times of the total mass of the magnetic powder.

[0023] Further, the rotation speed of the ball milling is 600-800 r / min, the temperature of the ball milling is 30-50℃, and the time of the ball milling is 3-5 h.

[0024] Further, the coupling agent is a titanate coupling agent.

[0025] Further, the titanate coupling agent is at least one selected from di(dioctyl pyrophosphoryloxy)glycol titanate, isopropyl tri(dioctyl pyrophosphoryloxy) titanate and di(octyl pyrophosphate) glycolate titanate.

[0026] Further, the composite binder comprises silicone rubber powder, epoxidized silicone elastomer powder and nitrile rubber powder.

[0027] Improper selection of the binder can result in unstable magnetic induction intensity of the magnetic sheet, and decreased resistance to heat and humidity and salt spray. The inventors have found through experiments that the use of silicone rubber powder, epoxidized silicone elastomer powder and nitrile rubber powder as the composite binder has the best effect, which may be due to the good compatibility of the binder components with the modified magnetic powder and the interaction between them, thereby obtaining an ultra-thin strong magnetic sheet with tightly integrated magnetic powder and binder, improving the stability of the magnetic induction intensity of the ultra-thin strong magnetic sheet, and the resistance to heat and humidity and salt spray.

[0028] Further, 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.

[0029] Further, the mass ratio of the silicone rubber powder, the epoxidized silicone elastomer powder and the nitrile rubber powder is 15:3:2.

[0030] Further, the silicone rubber powder is at least one selected from amorphous silicone rubber powder and spherical silicone rubber powder.

[0031] Further, the average particle size of the amorphous silicone rubber powder is 25-35 µm.

[0032] Furthermore, the particle size of the spherical silicone rubber powder is 5-15µm.

[0033] Furthermore, the acrylonitrile content of the nitrile rubber is 28-33%.

[0034] Furthermore, the thickness of the ultrathin strong magnetic sheet is 0.1-0.2 mm.

[0035] Furthermore, the magnetic induction intensity of the ultrathin strong magnetic sheet is greater than 700GS.

[0036] Secondly, the present invention provides a method for preparing an ultrathin strong magnetic sheet, comprising the following steps:

[0037] 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.

[0038] Thirdly, the present invention provides an application of an ultrathin strong magnetic sheet in the preparation of eyelash ornaments.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 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 achieves 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

[0041] 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.

[0042] 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.

[0043] 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.

[0044] Figure 4This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 1 after 7 days of neutral salt spray testing.

[0045] Figure 5 This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 2 after 7 days of neutral salt spray testing.

[0046] Figure 6 This is a photograph of the ultrathin strong magnetic sheet of Comparative Example 4 after 7 days of neutral salt spray testing. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] Example 1

[0050] 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.

[0051] The pretreatment agent is a carboxyl-terminated liquid butadiene-acrylonitrile rubber modified neopentyl glycol glycidyl ether.

[0052] 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.

[0053] The method for preparing magnetic powder using a pretreatment agent includes the following steps:

[0054] 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.

[0055] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0056] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0057] 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.

[0058] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0059] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0060] The acrylonitrile content of the nitrile rubber is 28%, and it is sourced from Ningbo Shunze Rubber Co., Ltd., model: NBR 2880.

[0061] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0062] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps:

[0063] 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.

[0064] Example 2

[0065] 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.

[0066] The pretreatment agent is an ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer.

[0067] The ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is from Jiayou Chemical, model: BF-2B.

[0068] The method for preparing magnetic powder using a pretreatment agent includes the following steps:

[0069] 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.

[0070] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0071] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0072] 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.

[0073] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0074] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0075] The acrylonitrile content of the nitrile rubber is 28%, and it is sourced from Ningbo Shunze Rubber Co., Ltd., model: NBR 2880.

[0076] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0077] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps:

[0078] 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 3

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is from Jiayou Chemical, model: BF-2B.

[0084] The method for preparing magnetic powder using a pretreatment agent includes the following steps:

[0085] 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.

[0086] The amount of the pretreatment agent used is 0.15 times the total mass of the rapidly quenched NdFeB magnetic powder.

[0087] The amount of acetone used is three times the total mass of the rapidly quenched NdFeB magnetic powder.

[0088] 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.

[0089] The silicone rubber powder is spherical silicone rubber powder with a particle size of 5µm, derived from Shin-Etsu KMP-597.

[0090] The epoxidized silicone elastomer powder is sourced from Shanghai Jiuying New Materials Co., Ltd., model number: DOWSIL™EP-2601.

[0091] The acrylonitrile content of the nitrile rubber is 28%, and it is sourced from Ningbo Shunze Rubber Co., Ltd., model: NBR 2880.

[0092] The coupling agent is di(dioctylpyrophosphate)ethylene glycol titanate.

[0093] The preparation method of the above-mentioned ultrathin strong magnetic sheet includes the following steps:

[0094] 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.

[0095] Example 4

[0096] 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.

[0097] Example 5

[0098] 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.

[0099] Example 6

[0100] 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.

[0101] Comparative Example 1

[0102] 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.

[0103] Comparative Example 2

[0104] 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.

[0105] Comparative Example 3

[0106] 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.

[0107] Comparative Example 4

[0108] 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.

[0109] Comparative Example 5

[0110] 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.

[0111] I. The following performance tests were conducted on Examples 1-6 and Comparative Examples 1-5.

[0112] 1. Magnetic induction intensity: tested using a gaussmeter.

[0113] 2. Service life:

[0114] (1) Placed at 25℃, the test period is 6 months, and the magnetic induction intensity is tested by a gaussmeter after the test.

[0115] (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.

[0116] (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.

[0117] Note: Magnetic induction intensity is tested at the edge of the sample.

[0118] II. Performance test results of Examples 1-6 and Comparative Examples 1-5

[0119] Table 1 Performance Test Results

[0120] Test item Magnetic induction strength / GS Magnetic induction strength / GS after 6 months at 25°C Magnetic induction strength / GS after 7 days at 60°C, 90% RH Rust occurrence after 7 days at 60°C, 90% RH Magnetic induction / GS after 7 days in neutral salt spray Rust occurrence after 7 days in 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

[0121] As can be seen from Table 1:

[0122] 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;

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] III. The following performance tests were conducted on Example 3:

[0128] Content of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, phthalates, hexabromocyclododecane, perfluorooctanoic acid, perfluorooctane sulfonic acid, and phthalates.

[0129] IV. Test Results of Example 3

[0130] Table 2 Performance Test Results

[0131]

[0132] 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 ferromagnetic sheet, characterized by, The raw materials include the following weight parts: magnetic powder 85-90 parts, composite binder 5-10 parts, coupling agent 2-6 parts; 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 a magnetic powder treated by a pretreatment agent; The pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer; Or, the pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer; Or, the pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether, carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and 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, high-magnetic-strength magnetic sheet of claim 1, wherein, The ferrite magnetic powder is selected from barium ferrite magnetic powder and / or strontium ferrite magnetic powder; and the neodymium iron boron magnetic powder is a rapidly quenched neodymium iron boron magnetic powder.

3. The ultra-thin, high magnetic strength magnetic sheet of claim 1, wherein, The elastomer content of the carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether is 50%; and the elastomer content of the carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether is 20%.

4. The ultra-thin, high magnetic strength magnetic sheet of claim 3, wherein, When the pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer, the mass ratio of the carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is 1-2:1-2; When the pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer, the mass ratio of the carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer is 1-2:1-2; When the pretreatment agent includes carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether, carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer, the total mass of the carboxyl-terminated liquid nitrile rubber modified neopentyl glycol glycidyl ether and the carboxyl-terminated liquid nitrile rubber modified cyclohexyl dimethanol diglycidyl ether and the mass of the ethylene-glycidyl methacrylate-vinyl acetate rubber copolymer are in the ratio of 1-2:1-2.

5. The ultrathin, high magnetic strength magnetic sheet of claim 4, wherein, The preparation method of the magnetic powder treated by the pretreatment agent includes the following steps: Mixing the magnetic powder, the pretreatment agent and the organic solvent, ball milling, filtering and drying after the ball milling are completed.

6. The ultrathin, high magnetic strength magnetic sheet of claim 1, wherein, 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.

7. The ultrathin, high magnetic strength magnetic sheet of claim 1, wherein, The thickness of the ultra-thin strong magnetic sheet is 0.1-0.2mm; and the magnetic induction intensity of the ultra-thin strong magnetic sheet is greater than 700GS.

8. The method of producing an ultrathin, high-magnetic-flux magnetic sheet according to any one of claims 1 to 7, characterized by, The method includes the following steps: After the above raw materials are uniformly mixed at high temperature according to the formula, calendering forming, cutting and magnetizing are sequentially performed to obtain the product.

9. Use of the ultrathin high-magnetic-strength magnetic sheet according to any one of claims 1-7 in the preparation of a mascara accessory.

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