An ultra-thin flexible magnetic lash magnetic sheet and its preparation method

Abstract

The present invention discloses an ultra-thin flexible magnetic adsorption eyelash magnetic sheet and a preparation method thereof, which relates to the technical field of magnetic adsorption eyelashes. Each group of eyelash magnetic sheets is composed of upper and lower magnetic sheets. Opposite adsorption magnetic poles are arranged on the two magnetic sheets respectively, and the magnetism of the opposite adsorption magnetic poles shows a gradient distribution of strong at the edge and weak in the middle on the magnetic sheet. The raw materials of the magnetic sheet include samarium iron nitride magnetic powder and polypropylene. Samarium iron nitride is non-toxic and resistant to sweat corrosion, and polypropylene meets the cosmetic grade standard, improving the biological safety and solving the problem of unreliable materials for traditional magnetic adsorption eyelashes. The magnetic sheet is designed as an opposite adsorption magnetization structure, and the upper and lower magnetic sheets can achieve firm adsorption, overcoming the defect of easy falling off of traditional magnetic adsorption eyelashes. The thickness is only 0.14 - 0.24 mm, and it does not break after being folded more than 500 times, conforming to the curvature of the eye, being comfortable to wear, and avoiding the defect of heaviness of traditional magnetic adsorption eyelashes.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic eyelashes, and specifically, to an ultra-thin flexible magnetic eyelash magnet piece and a preparation method thereof. Background Art

[0002] Traditional false eyelashes are composed of a connecting part and false eyelashes adhered to the connecting part. An adhesive is coated on one side of the connecting part, and when worn, the connecting part is pasted onto the eyelid. Such traditional false eyelashes have many defects, such as high use cost, the adhesive can cause irritation to the human skin, and it is inconvenient to wear and remove.

[0003] In order to overcome the above problems, magnetic false eyelashes have been developed, which are worn by combining a sheet-type eyelash provided with a magnetic element with magnetic eyeliner, or the upper and lower two pieces of eyelashes are magnetically adsorbed and connected from both sides of the real eyelashes. However, the existing magnetic eyelashes also have some deficiencies. For example, when the magnetic element is a hard magnetic sheet, it is heavy and the strong magnetic attraction is likely to damage the real eyelashes of the human eye; when the magnetic element is a flexible magnetic strip, the magnetic force is weak and it is prone to problems such as slipping and not fitting the root of the real eyelashes of the human eye, affecting the wearing effect and comfort. Summary of the Invention

[0004] The present invention provides an ultra-thin flexible magnetic eyelash magnet piece and a preparation method thereof, which solve the problems in the related art such as the magnetic eyelashes being thick, easy to break, easy to fall off, the wearing effect being unnatural, and the poor corrosion resistance of the material.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides an ultra-thin flexible magnetic eyelash magnet piece. Each group of eyelash magnet pieces is composed of two upper and lower magnet pieces. Opposite attracting magnetic poles are arranged on the two magnet pieces respectively, and the magnetism of the opposite attracting magnetic poles shows a gradient distribution of strong at the edge and weak in the middle on the magnet piece;

[0007] The magnet piece comprises the following raw materials in parts by weight: 85 - 89 parts of samarium iron nitride magnetic powder and 11 - 15 parts of polypropylene; preferably, 87 parts of samarium iron nitride magnetic powder and 13 parts of polypropylene.

[0008] As a further scheme of the present invention: the magnet piece further comprises the following raw materials: silane coupling agent, calcium stearate, zinc oxide;

[0009] Among them, the weight of the silane coupling agent is 1.5% of the samarium iron nitride magnetic powder; the weight of the calcium stearate is 0.3% of the polypropylene; the weight of the zinc oxide is 0.3% of the polypropylene.

[0010] As a further solution of the present invention: the samarium iron nitride magnetic powder is subjected to surface corrosion resistance treatment, and the method of surface corrosion resistance treatment is: adding phosphoric acid and corrosion inhibitor to the samarium iron nitride magnetic powder, stirring evenly to form a mixed system, and then reacting at 100 °C for 6 h.

[0011] As a further solution of the present invention: the dosage of the phosphoric acid is 1 wt% of the mixed system, and the dosage of the corrosion inhibitor is 1 wt% of the mixed system.

[0012] As a further solution of the present invention: the thickness of the magnetic sheet is 0.14 - 0.24 mm.

[0013] As a further solution of the present invention: the surface magnetic induction intensity of the magnetic sheet is 32 - 50 mT.

[0014] As a further solution of the present invention: the surface magnetic induction intensity at the edge of the magnetic sheet is greater than that at the center position, and the surface magnetic induction intensity at the edge of the magnetic sheet is 38 - 50 mT, and the surface magnetic induction intensity at the center position of the magnetic sheet is 30 - 42 mT.

[0015] Furthermore, the surface magnetic induction intensity from the center position to the edge of the magnetic sheet increases uniformly.

[0016] In the second aspect, the present invention also discloses a preparation method of the ultra-thin flexible magnetic eyelash magnetic sheet as described above, including the following steps:

[0017] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0018] Step 2: Feed the mixed material into a twin-screw extruder, and carry out melt blending and granulation at 180 - 210 °C to obtain pelletized materials;

[0019] Step 3: Place a layer of Teflon paper under the pressing fixture of a flat vulcanizer, then disperse and place the pelletized materials, place another Teflon paper above the pelletized materials, and then carry out pressing at 185 °C, controlling the pressing size to be and the pressing thickness to be 0.14 - 0.24 mm to obtain a magnetic sheet precursor;

[0020] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0021] Step 5: Carry out gradient-distributed directional magnetization on each group of sheet materials to form an attracting magnetization structure.

[0022] As a further solution of the present invention: in Step 5, the method of carrying out gradient-distributed directional magnetization on each group of sheet materials includes the following steps:

[0023] Step a: Place a single set of sheets between two layers of acrylic plates;

[0024] Step b: Horizontally center the sheet - holding plate on the conveyor belt;

[0025] Step c: Pre - orient the plate with the conveyor belt passing through a strong magnetic field with N - pole down and S - pole up. The strong magnetic field includes two N52 neodymium - iron - boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium - iron - boron strong magnetic blocks shows a gradient distribution with strong edges and weak middle, forming a unidirectional magnetic field in the middle;

[0026] Step d: Magnetize through a pulsed magnetic field;

[0027] Step e: After magnetization, reverse the two magnetic sheets to achieve an attracting magnetization structure.

[0028] As a further solution of the present invention: In step d, the intensity of the pulsed magnetic field is 3.5T and the magnetization time is 200ms.

[0029] The working principle and beneficial effects of the present invention are as follows:

[0030] 1. The ultra - thin flexible magnetic - attracting eyelash magnetic sheet of the present invention uses samarium - iron - nitride magnetic powder as the magnetic material and polypropylene composite material. Samarium - iron - nitride is non - toxic and resistant to sweat corrosion, and polypropylene meets the cosmetic - grade standard, improving biological safety and solving the problem of unreliable materials for traditional magnetic - attracting eyelashes. The magnetic sheet is designed with an attracting magnetization structure, and the upper and lower layers of magnetic sheets can achieve firm adsorption, overcoming the disadvantage of easy detachment of traditional magnetic - attracting eyelashes;

[0031] 2. The ultra - thin flexible magnetic - attracting eyelash magnetic sheet of the present invention is pressed by flat vulcanization technology, with a thickness of only 0.14 - 0.24mm, and it does not break after being folded more than 500 times. It fits the curvature of the eye, is comfortable to wear, and avoids the defect of heaviness of traditional magnetic - attracting eyelashes; It breaks through the thickness limit of the traditional rolling process, is conducive to the preparation of ultra - thin magnetic sheets, and reduces production costs;

[0032] 3. The ultra - thin flexible magnetic - attracting eyelash magnetic sheet of the present invention can control the surface magnetic induction intensity of the magnetic sheet within the range of 32 - 50mT by adjusting the magnetic powder content, realizing the classification of adsorption force, meeting the needs of different users for daily or thick styles, providing diversified choices; And it is designed with a gradient magnetization structure, which can achieve the balance between the natural curling and firm adsorption of eyelashes, thus obtaining an ultra - thin flexible, highly safe and controllable - magnetic - force magnetic - attracting eyelash. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following further describes the present invention in detail with reference to the drawings and specific embodiments.

[0034] Figure 1 It is a schematic diagram of laying a layer of Teflon paper under the pressing fixture of a flat vulcanizer in step three of Embodiment 2 of the present invention;

[0035] Figure 2 It is a schematic diagram of the magnetic sheet precursor in Step 3 of Embodiment 2 of the present invention;

[0036] Figure 3 It is a schematic diagram of the ultra-thin flexible magnetic eyelash magnetic sheet prepared in Embodiment 2 of the present invention. Detailed implementation manners

[0037] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0038] The experimental methods in the following embodiments are all conventional methods unless otherwise specified, and are carried out according to the technologies or conditions described in the literature in the field or according to the product instructions. The materials used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0039] Embodiment 1

[0040] Prepare samarium iron nitride magnetic powder: Add phosphoric acid and TTA methylbenzotriazole to the samarium iron nitride magnetic powder and stir evenly to form a mixed system, and then react at 100 °C for 6 h; among them, the dosage of phosphoric acid is 1% of the mixed system, and the dosage of the corrosion inhibitor is 1% of the mixed system.

[0041] Embodiment 2

[0042] This embodiment provides an ultra-thin flexible magnetic eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, KH550 silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and polypropylene resin and the dosages of other raw materials are as follows.

[0043] Samarium iron nitride magnetic powder (from Embodiment 1, average particle size 2 μm, coercivity Hc≥12 kOe): 87 wt%;

[0044] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0045] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0046] Calcium stearate: 0.3% of the mass of PP;

[0047] Zinc oxide: 0.3% of the mass of PP.

[0048] The preparation process of the above-mentioned ultra-thin flexible magnetic adsorption eyelash magnetic sheet is as follows:

[0049] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0050] Step 2: Feed the mixed material into a twin-screw extruder and carry out melt blending and granulation at 200 °C to obtain pelletized materials;

[0051] Step 3: As Figure 1-2 shown, place a layer of Teflon paper under the pressing fixture of the flat vulcanizer, then disperse and place the pelletized materials, place another Teflon paper above the pelletized materials, and then carry out pressing at 185 °C, control the pressing size to be and the pressing thickness to be 0.14 mm to obtain a magnetic sheet precursor;

[0052] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0053] Step 5: Place the single-group sheet materials between two layers of acrylic plates; horizontally center the acrylic plates clamping the sheet materials on the conveyor belt; pass the acrylic plates through a strong magnetic field with S on top and N at the bottom for pre-orientation, the strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve the adsorption magnetization structure, then the ultra-thin flexible magnetic adsorption eyelash magnetic sheet of this embodiment as Figure 3 shown is obtained.

[0054] Example 3

[0055] This embodiment provides an ultra-thin flexible magnetic adsorption eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and polypropylene resin and the usage amounts of other raw materials are specifically as follows.

[0056] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercivity Hc≥12 kOe): 87 wt%;

[0057] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0058] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0059] Calcium stearate: 0.3% of the mass of PP;

[0060] Zinc oxide: 0.3% of the mass of PP.

[0061] The preparation process of the above-mentioned ultra-thin flexible magnetic eyelash magnetic sheet is as follows:

[0062] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0063] Step 2: Put the mixed material into a twin-screw extruder and carry out melt blending and granulation at 180 °C to obtain pelletized materials;

[0064] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the pelletized materials, put another Teflon paper on top of the pelletized materials, and then carry out pressing at 185 °C, controlling the pressing size to be and the pressing thickness to be 0.19 mm to obtain a magnetic sheet precursor;

[0065] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0066] Step 5: Place the single-group sheet materials between two layers of acrylic plates; the acrylic plates clamping the sheet materials are placed horizontally and centered on the conveyor belt; pass the acrylic plates through a strong magnetic field with S on the top and N on the bottom for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve mutual attraction magnetization structure, then the ultra-thin flexible magnetic eyelash magnetic sheet of this embodiment is obtained.

[0067] Example 4

[0068] This embodiment provides an ultra-thin flexible magnetic eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and polypropylene resin and the usage amounts of other raw materials are specifically as follows.

[0069] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercive force Hc≥12 kOe): 87 wt%;

[0070] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0071] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0072] Calcium stearate: 0.3% of the mass of PP;

[0073] Zinc oxide: 0.3% of the mass of PP.

[0074] The preparation process of the above-mentioned ultra-thin flexible magnetic eyelash magnetic sheet is as follows:

[0075] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0076] Step 2: Put the mixed material into a twin-screw extruder, and carry out melt blending and granulation at 210 °C to obtain pelletized materials;

[0077] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the pelletized materials, put another Teflon paper on top of the pelletized materials, and then carry out pressing at 185 °C, controlling the pressing size to be and the pressing thickness to be 0.24 mm to obtain a magnetic sheet precursor;

[0078] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0079] Step 5: Place the single-group sheet materials between double-layer acrylic plates; the acrylic plates clamping the sheet materials are horizontally centered and placed on the conveyor belt; pass the acrylic plates through a strong magnetic field with S on top and N at the bottom for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve magnetic attraction and magnetization structure, then the ultra-thin flexible magnetic attraction eyelash magnetic sheet of this embodiment is obtained.

[0080] Example 5

[0081] This embodiment provides an ultra-thin flexible magnetic attraction eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and the polypropylene resin and the dosages of other raw materials are specifically as follows.

[0082] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercive force Hc≥12 kOe): 85 wt%;

[0083] Polypropylene (PP, melt index 20 g / 10 min): 15 wt%;

[0084] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0085] Calcium stearate: 0.3% of the mass of PP;

[0086] Zinc oxide: 0.3% of the mass of PP.

[0087] The preparation process of the above ultra-thin flexible magnetic attraction eyelash magnetic sheet is as follows:

[0088] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0089] Step 2: Put the mixed materials into a twin-screw extruder, melt and blend them at 200 °C for granulation to obtain pellets.

[0090] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the pellets, put another Teflon paper on top of the pellets, and then press at 185 °C, controlling the pressing size to be and the pressing thickness to be 0.14 mm to obtain the magnetic sheet precursor.

[0091] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine.

[0092] Step 5: Place the single-group sheet materials between two layers of acrylic plates; the acrylic plates clamping the sheet materials are placed horizontally and centered on the conveyor belt; pass the acrylic plates through a strong magnetic field of S up and N down for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks up and down, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve the attracting magnetization structure, and then the ultra-thin flexible magnetic eyelash magnetic sheet of this embodiment is obtained.

[0093] Example 6

[0094] This embodiment provides an ultra-thin flexible magnetic eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and polypropylene resin and the usage amounts of other raw materials are specifically as follows.

[0095] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercivity Hc≥12 kOe): 89 wt%;

[0096] Polypropylene (PP, melt index 20 g / 10 min): 11 wt%;

[0097] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0098] Calcium stearate: 0.3% of the mass of PP;

[0099] Zinc oxide: 0.3% of the mass of PP.

[0100] The preparation process of the above ultra-thin flexible magnetic eyelash magnetic sheet is as follows:

[0101] Step 1: Mix the magnetic sheet raw materials in proportion to obtain mixed materials.

[0102] Step 2: Put the mixed materials into a twin-screw extruder, and perform melt blending at 200 °C to granulate and obtain granular materials;

[0103] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the granular materials, put another Teflon paper on top of the granular materials, and then press at 185 °C, controlling the pressing size to be , and the pressing thickness is 0.14 mm to obtain the magnetic sheet precursor;

[0104] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheets through a sheet punching machine;

[0105] Step 5: Place the single-group sheets between double-layer acrylic plates; the acrylic plates clamping the sheets are placed horizontally and centered on the conveyor belt; let the acrylic plates pass through the strong magnetic field of S on the top and N on the bottom for pre-orientation along with the conveyor belt. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower parts, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize by a pulsed magnetic field with an intensity of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve the magnetization structure of attracting and magnetizing, then the ultra-thin flexible magnetic eyelash magnetic sheet of this embodiment is obtained.

[0106] Comparative Example 1

[0107] This embodiment provides an ultra-thin flexible magnetic eyelash magnetic sheet, which is composed of neodymium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the neodymium iron nitride magnetic powder and the polypropylene resin and the dosages of other raw materials are specifically as follows.

[0108] Neodymium iron boron magnetic powder: 87 wt%;

[0109] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0110] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0111] Calcium stearate: 0.3% of the mass of PP;

[0112] Zinc oxide: 0.3% of the mass of PP.

[0113] The preparation process of the above ultra-thin flexible magnetic eyelash magnetic sheet is as follows:

[0114] Step 1: Mix the magnetic sheet raw materials in proportion to obtain mixed materials;

[0115] Step 2: Put the mixed materials into a twin-screw extruder, and perform melt blending at 200 °C to granulate and obtain granular materials;

[0116] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse the pellets and place another piece of Teflon paper on top of the pellets. Then press at 185 °C, controlling the pressing size to be and the pressing thickness to be 0.14 mm to obtain the magnetic sheet precursor;

[0117] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0118] Step 5: Place the single-group sheet materials between two layers of acrylic plates; the acrylic plates clamping the sheet materials are horizontally centered on the conveyor belt; pass the acrylic plates through a strong magnetic field of S on top and N at the bottom for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the top and bottom, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution of strong at the edges and weak in the middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve the suction magnetization structure, and then the ultra-thin flexible magnetic suction eyelash magnetic sheet of this embodiment is obtained.

[0119] Comparative Example 2

[0120] This embodiment provides an ultra-thin flexible magnetic suction eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and the polypropylene resin and the usage amounts of other raw materials are specifically as follows.

[0121] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercivity Hc≥12 kOe): 87 wt%;

[0122] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0123] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0124] Calcium stearate: 0.3% of the mass of PP;

[0125] Zinc oxide: 0.3% of the mass of PP.

[0126] The preparation process of the above ultra-thin flexible magnetic suction eyelash magnetic sheet is as follows:

[0127] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0128] Step 2: Put the mixed material into a twin-screw extruder and carry out melt blending and granulation at 200 °C to obtain pellets;

[0129] Step 3: After the granular material is dried in a forced-air drying oven at 120°C for 7 hours, the granular material forms a rough sheet on a calender. The mold temperature is set at 120°C, the sheet output speed is 0.4 m / min, and the sheet thickness is 0.5 mm. The magnetic sheet is passed through three horizontal calenders. The first two hot rollers are at 100°C, and the last cold roller is at 10°C. The thickness of the magnetic sheet is precisely adjusted to decrease by 30% for each pass, resulting in a sheet with a thickness of 0.42 mm.

[0130] Step 4: Deburr the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheets through a sheet punching machine.

[0131] Step 5: Place the single-group sheets between two layers of acrylic plates; the acrylic plates clamping the sheets are horizontally centered on the conveyor belt; the acrylic plates are passed through a strong magnetic field with N on the top and S on the bottom for pre-orientation along with the conveyor belt. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, the two magnetic sheets are reversed to achieve mutual attraction magnetization structure, thus obtaining the ultra-thin flexible magnetic eyelash magnetic sheet of this embodiment.

[0132] Comparative Example 3

[0133] This embodiment provides an ultra-thin flexible magnetic eyelash magnetic sheet, which is composed of samarium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate, and zinc oxide raw materials; among them, the weight parts of the system formed by the samarium iron nitride magnetic powder and polypropylene resin and the dosages of other raw materials are specifically as follows.

[0134] Samarium iron nitride magnetic powder (from Example 1, average particle size 2 μm, coercive force Hc≥12 kOe): 87 wt%;

[0135] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0136] Silane coupling agent (KH-550): 1.5% of the mass of samarium iron nitride magnetic powder;

[0137] Calcium stearate: 0.3% of the mass of PP;

[0138] Zinc oxide: 0.3% of the mass of PP.

[0139] The preparation process of the above ultra-thin flexible magnetic eyelash magnetic sheet is as follows:

[0140] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0141] Step 2: Feed the mixed material into a twin-screw extruder and melt-blend it at 200°C to granulate, obtaining granular material;

[0142] Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the pellets. Place another Teflon paper on top of the pellets, and then press at 185°C, controlling the pressing size to be , with a pressing thickness of 0.14 mm, to obtain the magnetic sheet precursor;

[0143] Step 4: Clean the burrs of the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine;

[0144] Step 5: Place the single-group sheet materials between two layers of acrylic plates; the acrylic plates clamping the sheet materials are horizontally centered on the conveyor belt; pass the acrylic plates through a strong magnetic field with S on top and N at the bottom for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks is evenly distributed; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, reverse the two magnetic sheets to achieve the suction magnetization structure, and then the ultra-thin flexible magnetic suction eyelash magnetic sheet of this embodiment is obtained.

[0145] Comparative Example 4

[0146] This embodiment provides an ultra-thin flexible magnetic suction eyelash magnetic sheet, which is composed of neodymium iron nitride magnetic powder, polypropylene resin, silane coupling agent, calcium stearate, and zinc oxide raw materials; among them, the weight parts of the system formed by the neodymium iron nitride magnetic powder and the polypropylene resin, as well as the dosages of other raw materials, are specifically as follows.

[0147] Neodymium iron boron magnetic powder: 87 wt%;

[0148] Polypropylene (PP, melt index 20 g / 10 min): 13 wt%;

[0149] Silane coupling agent (KH-550): 1.5% of the mass of the samarium iron nitride magnetic powder;

[0150] Calcium stearate: 0.3% of the mass of PP;

[0151] Zinc oxide: 0.3% of the mass of PP.

[0152] The preparation process of the above ultra-thin flexible magnetic suction eyelash magnetic sheet is as follows:

[0153] Step 1: Mix the magnetic sheet raw materials in proportion to obtain a mixed material;

[0154] Step 2: Put the mixed material into a twin-screw extruder and carry out melt blending and pelletizing at 200°C to obtain pellets;

[0155] Step 3: After the pellets are dried in a forced-air drying oven at 120°C for 7 hours, the pellets are made into rough sheets by a calender. The die temperature is set at 120°C, the sheet output speed is 0.4 m / min, and the sheet thickness is 0.5 mm. The magnetic sheet is passed through three horizontal calenders. The first two hot rollers are at 100°C, and the last cold roller is at 10°C. The thickness of the magnetic sheet is adjusted precisely by reducing 30% each time, and a sheet with a thickness of 0.42 mm is obtained.

[0156] Step 4: Deburr the magnetic sheet precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheets by a sheet punching machine.

[0157] Step 5: Place the single-group sheets between two layers of acrylic plates; the acrylic plates clamping the sheets are horizontally centered on the conveyor belt; pass the acrylic plates through a strong magnetic field with N on the top and S on the bottom for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the top and bottom. The magnetism of the two N52 neodymium iron boron strong magnetic blocks is evenly distributed; a unidirectional magnetic field is formed in the middle; magnetize with a pulsed magnetic field of 3.5 T for 200 ms; after magnetization, the two magnetic sheets are reversed to achieve magnetic attraction and magnetization structure, and the ultra-thin flexible magnetic eyelash magnetic sheet of this embodiment is obtained.

[0158] The surface magnetic induction intensity of the flexible magnetic eyelash magnetic sheets prepared in Examples 2-6 and Comparative Examples 1-4 was detected. The detection method was: using a gaussmeter for testing.

[0159] The detection results are listed in Table 1 as follows:

[0160] Table 1

[0161]

[0162] By analyzing the data in Table 1, it can be known that: compared with Comparative Examples 1-4, the magnetic induction intensity at the edge of the flexible magnetic eyelash magnetic sheets prepared in Examples 2-6 is greater than that in the middle, and the distribution of the magnetic induction intensity is uniformly increasing from the middle to the edge. The magnetic induction intensity is at a moderate level, and it will not be too high or too low to cause problems such as too large suction force affecting removal or too small suction force being prone to falling off. The uniformly increasing distribution of the magnetic induction intensity from the middle to the edge can also make the suction force at the edge greater than that in the middle, thereby making the wearing effect more curly and natural, and causing less burden on the eyelashes and being more comfortable.

[0163] The basic physical properties of the flexible magnetic eyelash magnetic sheets prepared in Examples 2-6 and Comparative Examples 1-4 were detected, including the thickness of the magnetic sheet, the number of times of resistance to bending, and the folding phenomenon. The detection methods were:

[0164] Thickness of the magnetic sheet: Using a digital display vernier caliper;

[0165] Number of times of resistance to bending: Referring to the standard GB / T 457-2008.

[0166] Folding phenomenon: Place the magnetic sheet in a constant temperature bath at 25°C for 48 hours, then take it out, fold it 180°, and observe visually.

[0167] List the test results in Table 2 as follows:

[0168] Table 2

[0169]

[0170] By analyzing the data in Table 2, it can be known that: compared with Comparative Examples 1-2 and Comparative Example 4, the magnetic sheet thickness of the flexible magnetic adsorption eyelash magnetic sheets in Examples 2-6 is between 0.14-0.24 mm, the number of times of resistance to bending is greater than 500, and there are no cracks in the creases. This shows that the flexible magnetic adsorption eyelash magnetic sheets prepared by using samarium iron nitride magnetic powder as the production raw material and adopting the method of gradient distributed directional magnetization have a thinner thickness and better folding resistance performance.

[0171] Detect the corrosion resistance of the flexible magnetic adsorption eyelash magnetic sheets prepared in Examples 2-6 and Comparative Examples 1-4 by salt spray test. The test conditions are:

[0172] Salt spray test: Refer to the standard GB / T 10125-2021;

[0173] Test conditions: Neutral salt spray test (NSS);

[0174] Salt spray test chamber: Temperature control accuracy ±1°C, spray volume 1.0-2.0 mL / 80cm² / h;

[0175] Salt solution: 5wt% NaCl solution, pH value 6.5-7.2 (25°C).

[0176] List the test results in Table 3 as follows:

[0177] Table 3

[0178]

[0179] By analyzing the data in Table 3, it can be known that: compared with Comparative Examples 1 and 4, the surface change degree of the flexible magnetic adsorption eyelash magnetic sheets in Examples 2-6 is smaller within the same test time. This shows that using samarium iron nitride magnetic powder as the production raw material in the present invention enables the flexible magnetic adsorption eyelash magnetic sheets to have stronger corrosion resistance.

[0180] Detect the magnetic property attenuation rate of the flexible magnetic adsorption eyelash magnetic sheets prepared in Examples 2-6 and Comparative Examples 1-4 after salt spray test. The detection method is: measure the surface magnetic induction of the magnetic sheet after salt spray test, and calculate using the formula in combination with the surface magnetic induction intensity of the magnetic sheet before salt spray test.

[0181] The calculation results are listed in Table 4 as follows:

[0182] Table 4

[0183]

[0184] By analyzing the data in Table 4, it can be known that: compared with Comparative Examples 2-3, the magnetic attenuation rate of the flexible magnetic suction eyelash magnetic sheet in Examples 2-6 is lower within the same time, which indicates that using samarium iron nitride magnetic powder as the production raw material can make the magnetic retention effect of the flexible magnetic suction eyelash magnetic sheet better.

[0185] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ultra-thin flexible magnetic lash magnet piece, characterized in that, Each group of eyelash magnetic chips consists of upper and lower magnetic chips. Opposite attracting magnetic poles are arranged on the two magnetic chips respectively, and the magnetism of the opposite attracting magnetic poles shows a gradient distribution with strong edges and weak middle on the magnetic chips. The surface magnetic induction intensity at the edge of the magnetic chip is greater than that at the central position, and the surface magnetic induction intensity at the edge of the magnetic chip is 38 - 50 mT, while the surface magnetic induction intensity at the central position of the magnetic chip is 30 - 42 mT. The surface magnetic induction intensity from the central position to the edge of the magnetic chip increases uniformly. The magnetic chip comprises the following raw materials in parts by weight: 85 - 89 parts of samarium iron nitride magnetic powder and 11 - 15 parts of polypropylene. The preparation method of the ultra-thin flexible magnetic-attracting eyelash magnetic chip is as follows: Step 1: Mix the magnetic chip raw materials in proportion to obtain a mixed material. Step 2: Feed the mixed material into a twin-screw extruder and carry out melt blending and granulation at 180 - 210 °C to obtain pelletized materials. Step 3: Place a layer of Teflon paper under the pressing fixture of the flat vulcanizing machine, then disperse and place the pellets, put another Teflon paper on top of the pellets, and then press at 185 °C, controlling the pressing size to be 250 mm 250 mm, and the pressing thickness is 0.14 - 0.24 mm to obtain the magnetic sheet precursor; Step 4: Clean the burrs of the magnetic chip precursor, then cut it into two uniform pieces and stack them, and punch them into single-group sheet materials through a sheet punching machine. Step 5: Place the single-group sheet materials between double-layer acrylic plates. The plate clamping the sheet materials is horizontally centered on the conveyor belt. Pass the plate through a strong magnetic field with N on the upper side and S on the lower side for pre-orientation. The strong magnetic field includes two N52 neodymium iron boron strong magnetic blocks on the upper and lower sides, and the magnetism of the two N52 neodymium iron boron strong magnetic blocks corresponds to a gradient distribution with strong edges and weak middle. A unidirectional magnetic field is formed in the middle. Carry out magnetization by a pulsed magnetic field. The intensity of the pulsed magnetic field is 3.5 T, and the magnetization time is 200 ms. After magnetization, the two magnetic chips are reversed to achieve an opposite attracting magnetization structure.

2. The ultra-thin flexible magnetic eyelash magnetic sheet according to claim 1, wherein The magnetic chip further comprises the following raw materials: silane coupling agent, calcium stearate, zinc oxide. Among them, the weight of the silane coupling agent is 1.5% of the samarium iron nitride magnetic powder; the weight of the calcium stearate is 0.3% of the polypropylene; the weight of the zinc oxide is 0.3% of the polypropylene.

3. The ultra-thin flexible magnetic eyelash magnetic sheet according to claim 1, characterized in that The samarium iron nitride magnetic powder has been subjected to surface corrosion resistance treatment. The method of the surface corrosion resistance treatment is: add phosphoric acid and corrosion inhibitor to the samarium iron nitride magnetic powder and stir evenly to form a mixed system, and then react at 100 °C for 6 h.

4. The ultra-thin flexible magnetic eyelash magnetic sheet according to claim 3, wherein, The dosage of the phosphoric acid is 1 wt% of the mixed system, and the dosage of the corrosion inhibitor is 1 wt% of the mixed system.

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