Flexible magnetic sheet, preparation method thereof and false eyelash

Abstract

The invention provides a flexible magnetic sheet and a preparation method thereof and false eyelashes, and the flexible magnetic sheet comprises the following components in percentage by weight: 88-94 parts of samarium-iron-nitrogen magnetic powder, 6-10 parts of a binder, 0.7-1.5 parts of a coupling agent, 0.2-0.8 part of a lubricant and 0.2-0.8 part of a heat stabilizer; wherein the samarium iron nitrogen magnetic powder is granular, and the average particle size of the samarium iron nitrogen magnetic powder is 2-50 microns. The false eyelashes prepared by the method have better flexibility and stability and strong sweat corrosion resistance, and the flexible magnetic sheet has better flexibility, light weight, better suitability with the false eyelash body and longer service life, and has wide industrial application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of make-up tools, in particular to a flexible magnetic sheet, a preparation method thereof and false eyelashes. BACKGROUND

[0002] False eyelashes are a kind of make-up products used for sticking on the eyelid to enhance, lengthen and densify natural eyelashes, enhance the three-dimensional effect of the eyes, and thus beautify the eyes and improve the make-up effect. Traditional false eyelashes use a hand hooking process to fix the hair on a thread, and a hard knot is formed at the knot, resulting in uneven roots. When the false eyelashes are combined with a magnet, the combination is not firm and the false eyelashes are prone to falling off. Moreover, the existing magnets for false eyelashes have the problems of poor flexibility, weak magnetic force and easy falling of magnetic powder.

[0003] Therefore, researchers use glue to bond the magnet and the false eyelashes to enhance the firmness of the combination, but the bonding glue is easy to deform the magnet, thereby affecting the arc memory effect of the combination of the magnet, further affecting the user's experience and health. Specifically, firstly, the magnetic material used in the prior art has poor magnetic stability and fast magnetic force decay, so that the adsorption force of the magnet is insufficient and the magnet falls off, which cannot meet the long-term use requirement. Secondly, the traditional magnet has a thick, wide and heavy thickness, so that the foreign body sensation of the eyes is obvious, and the flexibility of the magnet is poor and the natural arc of the eyelid cannot be combined, so that the magnet is prone to displacement during movement, affecting the appearance and having the risk of firmness. Moreover, the compatibility of the magnetic powder and the bonding agent is poor, and the magnetic powder is easy to fall off under friction or sweat erosion, which may stimulate the skin of the eyes and thus pose a health risk.

[0004] Therefore, in view of the technical problems of the existing false eyelash magnetic sheet, such as poor flexibility, large weight, poor adaptability to the false eyelash body and poor durability, the present application provides a flexible magnetic sheet and a preparation method thereof to solve the above problems. SUMMARY

[0005] The main purpose of the present application is to provide a flexible magnetic sheet, a preparation method thereof and false eyelashes to solve the technical problems of the existing false eyelash magnetic sheet, such as poor flexibility, large weight, poor adaptability to the false eyelash body and poor durability.

[0006] In order to achieve the above purpose, according to one aspect of the present application, a flexible magnetic sheet is provided, which comprises, by weight percentage, 88-94 parts of samarium-iron-nitrogen magnetic powder, 6-10 parts of bonding agent, 0.7-1.5 parts of coupling agent, 0.2-0.8 parts of lubricant and 0.2-0.8 parts of heat stabilizer; wherein the samarium-iron-nitrogen magnetic powder is in a granular form, and the average particle size is 2-50 μm.

[0007] Further, the flexible magnetic sheet has a thickness of 0.1-0.4 mm, a width of 0.6-1.0 mm, and a length of 3-12 mm, and the flexible magnetic sheet has a density of 4.0-5.0 g / cm 3 Preferably, the average particle size of the samarium-iron-nitrogen magnetic powder is 2-50 μm.

[0008] Further, in the flexible magnetic sheet, the binder is selected from silicone rubber and / or thermoplastic polyurethane elastomer.

[0009] Further, the coupling agent is selected from one or more of titanate, silane, and aluminate; preferably, the lubricant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, sodium stearate, aluminum stearate, or lithium stearate; and preferably, the heat stabilizer comprises a mixture of epoxy resin and silicone elastomer, and the weight ratio of the epoxy resin to the silicone elastomer is 3:1.

[0010] Further, the samarium-iron-nitrogen magnetic powder is a samarium-iron-nitrogen magnetic powder obtained by surface treatment of a samarium-iron-nitrogen raw magnetic powder, and the samarium-iron-nitrogen magnetic powder has an oxide protective film with a thickness of 0.01-0.03 μm; preferably, in the samarium-iron-nitrogen magnetic powder, the content of samarium metal is 18-24%, and the phase structure of the samarium-iron-nitrogen magnetic powder is 2:17 phase and / or 1:9 phase; preferably, the flexible magnetic sheet comprises a magnetic sheet body and a coating layer, the coating layer is coated on the outer surface of the magnetic sheet body, the material of the coating layer is medical-grade fluororubber, the thickness of the coating layer is 0.01-0.03 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:(10-15); and preferably, the coercive force of the flexible magnetic sheet is ≥8 kOe, the magnetic decay rate is ≤5% / 30 times, and the elongation at break is ≥15%.

[0011] In order to achieve the above object, according to one aspect of the present application, there is provided a preparation method of a flexible magnetic sheet, the preparation method comprising: step S1, taking pretreated samarium-iron-nitrogen magnetic powder into a high-speed mixer for dispersion treatment, adding a coupling agent solution for solidification treatment, and then mixing with a binder, a lubricant, and a heat stabilizer for mixing treatment to obtain a mixture; and step S2, taking the mixture for successively rolling, radian memory plasticizing, and cutting treatment to obtain the flexible magnetic sheet.

[0012] Further, the pretreated samarium-iron-nitrogen magnetic powder is obtained by vacuum drying at 80°C for 2-3 h; preferably, the dispersion treatment is performed at room temperature, and the treatment time is 5-30 min; preferably, the coupling agent solution is a coupling agent solution diluted by a diluent, and the diluent is ethanol; preferably, the solidification treatment is performed at a temperature of 70-90°C for 1-3 h, and the stirring speed is 800-1200 rpm; and preferably, after the solidification treatment, the solidification-treated material is successively naturally cooled to room temperature and screened by a screen mesh before the mixing treatment.

[0013] Further, the temperature of the calendering and rolling treatment in step S2 is 100-130 DEG C, and the thickness of the calendering and rolling treated material is 0.1-0.4 mm after the calendering and rolling treatment; preferably, the radian memory plastic treatment comprises: placing the calendered material in an arc-shaped mold, and pressing at 10-20 kg / cm 2 After treating for 5-20 min, the radian memory plastic treated material is obtained by natural cooling; preferably, the temperature of the mixing treatment is 80-100 DEG C.

[0014] According to another aspect of the present application, a false eyelash is provided, comprising a false eyelash body, a flexible magnetic sheet, and a composite adhesive, wherein the flexible magnetic sheet is the flexible magnetic sheet described above, or is obtained by the preparation method of the flexible magnetic sheet described above.

[0015] Further, the false eyelash body is obtained by chemically sharpening the original false eyelash body, and the weight of the false eyelash body is reduced by 30% compared with the weight of the original false eyelash body; preferably, the composite adhesive comprises, by weight percentage: 25-35 parts of hydroxyethyl methacrylate, 15-20 parts of silicone modified polyurethane, 10-15 parts of C5 hydrogenated petroleum resin, 5-8 parts of nano silicon dioxide, 1.5-2.5 parts of initiator, 0.3-0.8 parts of leveling agent, 0.1-0.3 parts of antioxidant, and the balance of acetic acid; preferably, the weight of the samarium-iron-nitrogen magnetic powder accounts for 55-70% of the weight of the false eyelash; preferably, the preparation method of the false eyelash comprises: coating the composite adhesive on the outer surface of the flexible magnetic sheet, and attaching the fish line at the root of the false eyelash body material to the outer surface of the flexible magnetic sheet to obtain the false eyelash; preferably, the fish line at the root of the false eyelash body material is a biomimetic fiber, and the diameter of a single biomimetic fiber is 30-50 μm; preferably, the composite adhesive is coated on the outer surface of the flexible magnetic sheet, the diameter of the adhesive points for coating the composite adhesive is ≤0.5 mm, and the spacing is 2-3 mm; preferably, the viscosity of the composite adhesive at 25 DEG C is 1500-2500 Pa·S, and the amount of coating the composite adhesive is 0.005-0.1 mL / cm 2 .

[0016] The flexible magnetic sheet prepared by the technical solution of the present application has good flexibility, light weight, good adaptability to the false eyelash body, good durability, and long service life. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings accompanying the specification of the present application serve to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0018] Figure 1 a false eyelash obtained by the preparation method according to the present application is shown; and

[0019] Figure 2 A size angle diagram of a flexible magnetic sheet prepared according to the preparation method of the present application is shown. DETAILED DESCRIPTION

[0020] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] According to the background section, the prior art false eyelash magnetic sheet has the technical problems of poor flexibility, or large weight, or poor adaptability to the false eyelash body, or poor durability. Based on this, the present application provides a flexible magnetic sheet, which comprises, in percentage by weight, 88-94 parts of samarium-iron-nitrogen magnetic powder, 6-10 parts of a binder, 0.7-1.5 parts of a coupling agent, 0.2-0.8 parts of a lubricant, and 0.2-0.8 parts of a thermal stabilizer; wherein the samarium-iron-nitrogen magnetic powder is in a granular form, and has an average particle size of 2-50 μm.

[0022] In the present application, samarium-iron-nitrogen magnetic powder is creatively used as a magnetic material. First, based on the characteristics of high coercivity (strong anti-demagnetization ability), high chemical stability (resistant to sweat erosion), fine particle size (suitable for ultra-thin molding), and low density (7.4-7.5 g / cm3) of samarium-iron-nitrogen (SmFeN) material, the magnetic sheet prepared therefrom has good flexibility and magnetic stability, and the false eyelash prepared therefrom can be adapted to different eye shapes. In particular, the samarium-iron-nitrogen magnetic powder is in a granular form, and has an average particle size of 2-50 μm, so that the magnetic powder is light in weight and not easy to fall off. Second, the flexible magnetic sheet provided in the present application is added with a binder, a coupling agent, and other additives, thereby improving the interfacial bonding force between the magnetic powder and the additives, enhancing the flexibility of the flexible magnetic sheet, and improving its stability and service life.

[0023] In a preferred embodiment, the flexible magnetic sheet has a thickness of 0.1-0.4 mm, a width of 0.6-1.0 mm, and a length of 3-12 mm, and the density of the flexible magnetic sheet is 4.0-5.0 g / cm3. 3 The flexible magnetic sheet assembly has an ultra-thin size and is light in weight, and the false eyelash prepared therefrom reduces the foreign body sensation during wearing, thereby improving the service life. More preferably, the average particle size of the samarium-iron-nitrogen magnetic powder is 2-50 μm. This further improves the high flexibility of the flexible magnetic sheet, so that it can be naturally curved with the eyelid curvature, is adapted to different eye shapes, and is not easy to shift during user activities.

[0024] To further improve the flexibility and stability of the flexible magnetic sheet, preferably in the flexible magnetic sheet, preferably the binder is selected from silicone rubber and / or thermoplastic polyurethane elastomer; preferably the coupling agent is selected from one or more of titanate, silane, aluminate; preferably the lubricant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, sodium stearate, aluminum stearate or lithium stearate; preferably the heat stabilizer includes a mixture of epoxy resin and silicone elastomer, and the weight ratio of epoxy resin to silicone elastomer is 3:1, to improve the thermal stability and long-term service life of the flexible magnetic sheet.

[0025] In a preferred embodiment, the samarium iron nitride magnetic powder is a samarium iron nitride raw magnetic powder coated with an oxidation protective film after surface treatment, and the thickness of the oxidation protective film is 0.01-0.03 μm; the oxidation protective film is formed on the surface of the samarium iron nitride bulk magnetic powder to further prevent the magnetic powder from falling off and improve the stability of the magnetic powder, solving the problem of easy falling off of existing magnetic powder in the application process; preferably, the content of samarium metal in the samarium iron nitride magnetic powder is 18-24%, and the phase structure of the samarium iron nitride magnetic powder is 2:17 phase and / or 1:9 phase; more preferably, the flexible magnetic sheet includes a magnetic sheet body and a coating layer, the coating layer is coated on the outer surface of the magnetic sheet body, the material of the coating layer is medical-grade fluororubber, the thickness of the coating layer is 0.01-0.03 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:(10-15); the coating layer can isolate the erosion of sweat, further preventing the magnetic powder from falling off and enhancing the stability of the flexible magnetic sheet; preferably, the coercive force (Hcj) of the flexible magnetic sheet is ≥8 kOe, the magnetic decay rate is ≤5% / 30 times, and the elongation at break is ≥15%, the flexible magnetic sheet exhibits excellent flexibility and magnetic stability.

[0026] In another aspect, the application provides a preparation method of a flexible magnetic sheet, which includes: step S1, taking the pretreated samarium iron nitride magnetic powder into a high-speed mixer for dispersion treatment, adding a coupling agent solution for solidification treatment, and then mixing with a binder, a lubricant and a heat stabilizer for mixing treatment to obtain a mixture; step S2, taking the mixture for calendering, radian memory plasticity and cutting treatment in sequence to obtain a flexible magnetic sheet.

[0027] The skilled person first takes the pretreated samarium iron nitride magnetic powder into a high-speed mixer for dispersion treatment, adds a coupling agent solution for solidification treatment, and then mixes with a binder, a lubricant and a heat stabilizer for mixing treatment to obtain a mixture; then, the mixture is taken for calendering, radian memory plasticity and cutting treatment in sequence to obtain a flexible magnetic sheet. The preparation method is simple and easy to operate, suitable for large-scale production, and has broad industrial application prospects, and the flexible magnetic sheet prepared by the method has excellent flexibility, magnetic stability and excellent adaptability.

[0028] In some preferred embodiments, the pretreated samarium-iron-nitrogen magnetic powder is obtained by vacuum drying the pretreated samarium-iron-nitrogen magnetic powder at 80 DEG C for 2-3 hours to remove the residual moisture on the surface; preferably, the dispersion treatment is performed at room temperature for 5-30 minutes to uniformly disperse the samarium-iron-nitrogen magnetic powder; preferably, the coupling agent solution is a coupling agent solution diluted by a diluent, and the diluent is ethanol; preferably, the curing treatment is performed at a temperature of 70-90 DEG C for 1-3 hours at a stirring speed of 800-1200 rpm to fully react the coupling agent with the samarium-iron-nitrogen magnetic powder; and preferably, after the curing treatment, the cured material is naturally cooled to room temperature and then screened by a screen mesh before the mixing treatment.

[0029] In a preferred embodiment, in step S2, the temperature for the calendering treatment is 100-130 DEG C, and the thickness of the calendered material obtained after the calendering treatment is 0.1-0.4 mm; to ensure the uniform thickness of the flexible magnetic sheet and help the material to form a micro-orientation conducive to the arc memory; preferably, the arc memory plastic treatment comprises: placing the calendered material in an arc-shaped mold, pressurizing to 10-20 kg / cm 2 After the treatment for 5-20 minutes, the arc memory plastic treated material is obtained by natural cooling, to strengthen the arc memory function by imparting an initial arc; more preferably, the temperature for the mixing treatment is 80-100 DEG C.

[0030] In another aspect, the application also provides a false eyelash, which comprises a false eyelash body, a flexible magnetic sheet, and a composite adhesive, wherein the flexible magnetic sheet is the flexible magnetic sheet described above or obtained by the preparation method of the flexible magnetic sheet described above. The false eyelash has good stability, light weight, and good adaptability, and is suitable for long-term wear.

[0031] In a preferred embodiment, the false eyelash body is obtained by chemically sharpening the original false eyelash body, and the weight of the false eyelash body is reduced by 30% compared with the weight of the original false eyelash body, so that the shape of the false eyelash tip is closer to that of a real human eyelash, and the naturalness and lightness are improved; preferably, the composite adhesive comprises, by weight percentage, 25-35 parts of hydroxyethyl methacrylate, 15-20 parts of silicone-modified polyurethane, 10-15 parts of C5 hydrogenated petroleum resin, 5-8 parts of nano-silicon dioxide, 1.5-2.5 parts of an initiator, 0.3-0.8 parts of a leveling agent, 0.1-0.3 parts of an antioxidant, and the balance of acetic acid; preferably, the weight of the samarium-iron-nitrogen magnetic powder accounts for 55-70% of the weight of the false eyelash.

[0032] In a preferred embodiment, the method for preparing the false eyelash comprises: applying the composite adhesive on the outer surface of the flexible magnetic sheet, and adhering the fish line at the root of the false eyelash body material to the outer surface of the flexible magnetic sheet, thereby obtaining the false eyelash; preferably the fish line at the root of the false eyelash body material is a biomimetic fiber, and the diameter of a single biomimetic fiber is 30-50 μm.

[0033] In a preferred embodiment, the composite adhesive is applied on the outer surface of the flexible magnetic sheet, the diameter of the adhesive points applied by the composite adhesive is ≤0.5 mm, and the spacing is ~3 mm; more preferably the viscosity of the composite adhesive at 25°C is 1500-2500 Pa·S, and the amount of the composite adhesive applied is 0.005-0.1 mL / cm 2 The root of the false eyelash in the present application adopts a specially prepared fish line, replacing the traditional hand hooking process, thereby avoiding the generation of small bumps and improving the smoothness of wearing.

[0034] In some preferred embodiments, the false eyelash body is obtained by chemically sharpening the original false eyelash body, wherein the chemical sharpening process specifically comprises: using strong acid and strong base to decompose and sharpen at different concentrations, and the weight of the false eyelash body is reduced by 30% compared with the weight of the traditional magnetic eyelash false eyelash. The core of preparing the peak of the false eyelash body by using PBT (polybutylene terephthalate) chemical fiber and strong acid and strong base is a chemical etching method, which utilizes the selective corrosion of acid and alkali on the surface of the fiber to form a rough and convex structure similar to the peak of the false eyelash body. The reaction conditions need to be strictly controlled to avoid the degradation of the whole fiber. The specific preparation process comprises: first, a pretreatment stage: the PBT chemical fiber is cleaned and dried to remove surface dirt and impurities, ensuring uniform etching in the subsequent process. Then, a chemical etching stage: the pretreated fiber is immersed in a strong alkali solution of sodium hydroxide at a specific concentration, and the reaction is carried out at a constant temperature of 40-60°C. The strong alkali will preferentially corrode the amorphous region on the surface of the fiber, forming small pits. As the reaction proceeds, the pits deepen and expand, gradually forming a "peak" structure. Then, a neutralization and cleaning stage: after the etching reaches the desired effect, the fiber is immediately transferred to a weak acid solution of acetic acid to neutralize the residual alkali, and then repeatedly washed with deionized water until the pH value of the fiber is neutral. Finally, a post-treatment stage: the cleaned fiber is dried and shaped to obtain the final product of the PBT chemical fiber with a peak on the surface.

[0035] The present application will be further described in detail below in combination with specific examples, which cannot be understood as limiting the scope of the present application.

[0036] Example 1

[0037] The flexible magnetic sheet comprises 90 parts of samarium iron-nitrogen magnetic powder, 7.5 parts of a binder, 1.5 parts of a coupling agent, 0.5 parts of a lubricant, and 0.5 parts of a thermal stabilizer; wherein the samarium iron-nitrogen magnetic powder is in a granular form with an average particle size of 10-20 μm. The flexible magnetic sheet has a thickness of 0.15 mm, a width of 0.6 mm, and a length of 10 mm; the weight of the samarium iron-nitrogen magnetic powder accounts for 60% of the weight of the false eyelash, and the density of the flexible magnetic sheet is 4.5 g / cm 3 .

[0038] The binder is a thermoplastic polyurethane elastomer, the coupling agent is a titanate coupling agent, the lubricant is zinc stearate, and the thermal stabilizer comprises a mixture of an epoxy resin and a silicone elastomer, and the weight ratio of the epoxy resin to the silicone elastomer is 3:1.

[0039] The samarium iron-nitrogen magnetic powder is a samarium iron-nitrogen magnetic powder obtained by surface treatment of a raw samarium iron-nitrogen magnetic powder, and the thickness of the oxidation protective film is 0.15 μm. In the samarium iron-nitrogen magnetic powder, the content of samarium metal is 20%, and the phase structure of the samarium iron-nitrogen magnetic powder is a 2:17 phase. The thickness of the coating layer of the medical-grade fluororubber material is 0.02 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:12.

[0040] The preparation method of the flexible magnetic sheet comprises the following steps: S1, drying the samarium iron-nitrogen magnetic powder at 80°C under vacuum for 2 h to obtain pretreated samarium iron-nitrogen magnetic powder, adding the pretreated samarium iron-nitrogen magnetic powder into a high-speed mixer for dispersion treatment at room temperature for 10 min, adding an ethylene-diluted coupling agent solution for curing treatment at a temperature of 80°C for 3 h with a stirring speed of 1200 rpm, naturally cooling to room temperature after the treatment, screening through a screen, and mixing the pretreated samarium iron-nitrogen magnetic powder with a binder, a lubricant, and a thermal stabilizer to obtain a mixture at a mixing temperature of 90°C. S2, taking the mixture for calendering, radian memory plasticity, and cutting to obtain the flexible magnetic sheet. The calendering temperature is 100°C, and the thickness of the calendered material is 0.3 mm after the calendering treatment. The calendered material is placed in an arc-shaped mold, pressurized to 20 kg / cm 2 at 105°C for 15 min, and naturally cooled to obtain the radian memory plasticity treated material. Figure 2 The flexible magnetic sheet is shown in the size and angle diagram.

[0041] The false eyelash preparation method comprises the following steps: coating a composite adhesive on the outer surface of the flexible magnetic sheet, and attaching fish-silk threads at the root of the false eyelash body material to the outer surface of the flexible magnetic sheet to obtain the false eyelash. Figure 1 The false eyelash is shown in the diagram.

[0042] The false eyelash body is obtained by sequentially treating the false eyelash original body by a chemical tip-removing process and a carbon fiber anti-rebound wire, and the weight of the false eyelash body is reduced by 30% compared with the weight of the false eyelash original body. The chemical tip-removing process specifically comprises: a pretreatment stage: the PBT chemical fiber is cleaned and dried to remove surface dirt and impurities and ensure uniform etching in the subsequent process. Then, a chemical etching stage: the pretreated fiber is immersed in a water solution of sodium hydroxide and dodecyl dimethyl benzyl ammonium chloride heated to 100 DEG C for tip-sharpening treatment, wherein the concentration of sodium hydroxide is 13wt%, and the concentration of dodecyl dimethyl benzyl ammonium chloride is 0.5wt%; constant temperature reaction at 100 DEG C. The strong alkali will preferentially erode the amorphous region on the surface of the fiber to form a small pit, and as the reaction proceeds, the pit deepens and expands, gradually forming a "peak" structure. Then, a neutralization and cleaning stage: after the etching reaches the desired effect, the fiber is immediately transferred to a weak acid acetic acid solution to neutralize the residual alkali, and then repeatedly washed with deionized water until the pH value of the fiber is neutral. Finally, a post-treatment stage: the cleaned fiber is dried and shaped to obtain the final PBT chemical fiber product with a surface with a peak.

[0043] The carbon fiber anti-rebound wire treatment comprises: high temperature setting equipment is used to set at 139 DEG C for 2h to ensure that the carbon fiber anti-rebound wire has a specific toughness.

[0044] The composite adhesive comprises, by weight percentage: 35 parts of hydroxyethyl methacrylate, 20 parts of silicone modified polyurethane, 15 parts of C5 hydrogenated petroleum resin, 8 parts of nano silicon dioxide, 2 parts of initiator, 0.8 parts of leveling agent, 0.3 parts of antioxidant, and the balance of acetic acid. The viscosity of the composite adhesive at 25 DEG C is 2000Pa·S, and the amount of the composite adhesive coated is 0.01mL / cm 2 .

[0045] The fundamental fish silk wire width of the false eyelash body material is 25mm, which is a biomimetic fiber, and the diameter of a single biomimetic fiber is 40μm; the composite adhesive is coated on the outer surface of the flexible magnetic sheet, and the diameter of the adhesive point of the composite adhesive is 0.4mm and the spacing is 2mm.

[0046] The false eyelash body is obtained by chemical tip treatment on the original false eyelash body, and the chemical tip treatment specifically includes: using PBT (polybutylene terephthalate) chemical fiber to prepare the core of the hair peak by strong acid and strong base layering, and using the selective corrosion of acid and alkali on the fiber surface to form a rough convex structure similar to the "hair peak". The method needs to strictly control the reaction conditions to avoid the degradation of the whole fiber. The specific preparation process includes: first, the pretreatment stage: the PBT chemical fiber is cleaned and dried to remove surface dirt and impurities, and ensure uniform etching in the following stage. Then, the chemical etching stage: the pretreated fiber is immersed in a strong alkali solution of sodium hydroxide with a certain concentration, and the reaction is carried out at a constant temperature of 60°C. The strong alkali will preferentially corrode the amorphous area on the surface of the fiber, forming small pits. As the reaction proceeds, the pits deepen and expand, and gradually form a "hair peak" structure. Then, the neutralization and cleaning stage: after the etching reaches the desired effect, the fiber is immediately transferred to a weak acid acetic acid solution to neutralize the residual alkali, and then repeatedly washed with deionized water until the pH value of the fiber is neutral. Finally, the post-treatment stage: the cleaned fiber is dried and shaped to obtain the final product of PBT chemical fiber with hair peaks on the surface.

[0047] Example 2

[0048] The difference from example 1 is that the flexible magnetic sheet includes: 88 parts of samarium iron-nitrogen magnetic powder, 10 parts of binder, 1 part of coupling agent, 0.5 parts of lubricant and 0.5 parts of heat stabilizer; the weight of the samarium iron-nitrogen magnetic powder accounts for 55% of the weight of the false eyelashes, and the density of the flexible magnetic sheet is 4.2 g / cm 3 , the average particle size of the samarium metal is 30-40 μm and is 1:9 phase samarium iron-nitrogen magnetic powder. The thickness of the flexible magnetic sheet is 0.1 mm, the width is 0.8 mm, and the length is 8 mm; the thickness of the medical grade fluororubber material coating layer is 0.01 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:10.

[0049] The width of the false eyelash body is 20 mm, the diameter of the bionic fiber is 30 μm, the diameter of the glue point coated with the composite adhesive is 0.3 mm, and the interval is 2 mm.

[0050] Example 3

[0051] The difference from example 1 is that the flexible magnetic sheet includes: 92 parts of samarium iron-nitrogen magnetic powder, 6 parts of binder, 1 part of coupling agent, 0.5 parts of lubricant and 0.5 parts of heat stabilizer; the weight of the samarium iron-nitrogen magnetic powder accounts for 70% of the weight of the false eyelashes, and the average particle size is 30-40 μm, and the density of the flexible magnetic sheet is 4.7-4.8 g / cm 3 , the content of samarium metal in the magnetic powder is 22%, the thickness of the flexible magnetic sheet is 0.2 mm, the width is 1 mm, and the length is 12 mm; the thickness of the medical grade fluororubber coating layer is 0.03 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:15.

[0052] The width of the false eyelash body is 29 mm, the diameter of the biomimetic fiber is 50 μm, the diameter of the glue point coated by the composite adhesive is 0.5 mm, and the interval is 3 mm.

[0053] Example 4

[0054] The difference from Example 1 is only that the flexible magnetic sheet comprises 90 parts of samarium-nitrogen magnetic powder, 8 parts of binder, 1 part of coupling agent, 0.5 part of lubricant, and 0.5 part of thermal stabilizer; the weight of the samarium-nitrogen magnetic powder accounts for 58% of the weight of the false eyelash, and the average particle size is 2 μm; the density of the flexible magnetic sheet is 4.3 g / cm 3 ; the thickness of the samarium metal flexible magnetic sheet is 0.3 mm, the width is 0.7 mm, and the length is 9 mm; the thickness of the medical-grade fluororubber coating layer is 0.02 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:10.

[0055] The width of the false eyelash body is 22 mm, the diameter of the biomimetic fiber is 40 μm, the diameter of the glue point coated by the composite adhesive is 0.1 mm, and the interval is 3 mm.

[0056] Example 5

[0057] The difference from Example 1 is only that the flexible magnetic sheet comprises 88 parts of samarium-nitrogen magnetic powder, 10 parts of binder, 1 part of coupling agent, 0.5 part of lubricant, and 0.5 part of thermal stabilizer; the weight of the samarium-nitrogen magnetic powder accounts for 56% of the weight of the false eyelash, and the average particle size is 45-50 μm; the density of the flexible magnetic sheet is 4.2-4.3 g / cm 3 ; the thickness of the samarium metal flexible magnetic sheet is 0.2 mm, the width is 1 mm, and the length is 5 mm; the thickness of the medical-grade fluororubber coating layer is 0.03 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:15.

[0058] The width of the false eyelash body is 21 mm, the diameter of the biomimetic fiber is 50 μm, the diameter of the glue point coated by the composite adhesive is 0.2 mm, and the interval is 2 mm.

[0059] Performance test

[0060] 1) Mechanical property

[0061] The permanent magnetic material testing device is used to measure the magnetic coercive force and the magnetic decay rate of the material, and the universal material testing machine is used to test the breaking elongation of the material.

[0062] 2) Corrosion resistance

[0063] Take the false eyelashes in the humidity of 40~50%, the temperature is 35~45 DEG C, simulates the sweat corrosion test (sweat generally sodium chloride content is less than 0.3wt%), in the concentration of 0.5wt% brine immersion treatment, test the corrosion rust resistance performance. Among them, immersion 300~360 days after the product no deformation then performance is excellent;Immersion 250~299 days after the product no deformation then performance is good;Immersion 150~249 days after the product no deformation then performance is qualified;Immersion less than 150 days after the product no deformation then performance is poor.

[0064] Take the above example to test the performance, and the test results are shown in Table 1.

[0065] Table 1

[0066] Coercive force of magnetic sheet (kOe) Magnetic decay rate (% / 30 times) Elongation at break (%) Monocular weight (g) Magnetic powder drop amount (g) Sweat corrosion resistance Example 1 17 3.2 39.39 0.08 0 Good Example 2 15 2.5 48.96 0.06 0 Good Example 3 15 2.8 43.65 0.1 0 Good Example 4 9 4.1 34.78 0.075 0 Good Example 5 10 2.1 50.23 0.062 0 Good

[0067] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0068] In the present application, samarium iron nitrogen magnetic powder is used as the magnetic powder material, which has the characteristics of high coercivity, high chemical stability, suitable particle size and low density, so that the magnetic sheet prepared therefrom has relatively good flexibility and magnetic stability, and the false eyelashes prepared therefrom can be adapted to different eye shapes. In particular, the samarium iron nitrogen magnetic powder is light in weight and not easy to fall off. Moreover, the flexible magnetic sheet provided in the present application is added with a bonding agent, a coupling agent and other additives, so as to improve the interfacial bonding force between the magnetic powder and the additives, thereby enhancing the flexibility of the flexible magnetic sheet and improving its stability and service life.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A flexible magnetic sheet, characterized by, The flexible magnetic sheet comprises, by weight percentage, 88-94 parts of samarium iron nitride magnetic powder, 6-10 parts of a binder, 0.7-1.5 parts of a coupling agent, 0.2-0.8 parts of a lubricant, and 0.2-0.8 parts of a heat stabilizer; wherein the samarium iron nitride magnetic powder is in a granular form with an average particle size of 2-50 μm.

2. The flexible magnetic sheet according to claim 1, wherein The flexible magnetic sheet has a thickness of 0.1-0.4 mm, a width of 0.6-1.0 mm, a length of 3-12 mm, and a density of 4.0-5.0 g / cm 3 ; and / or, The average particle size of the samarium iron nitride magnetic powder is 2-50 μm.

3. The flexible magnetic sheet according to claim 1, wherein In the flexible magnetic sheet, the binder is selected from silicone rubber and / or thermoplastic polyurethane elastomer.

4. The flexible magnetic sheet of claim 1, wherein, The coupling agent is selected from one or more of titanate, silane, and aluminate; and / or, The lubricant is selected from one or more of zinc stearate, calcium stearate, magnesium stearate, sodium stearate, aluminum stearate, or lithium stearate; and / or, The heat stabilizer comprises a mixture of epoxy resin and silicone elastomer, and the weight ratio of the epoxy resin to the silicone elastomer is 3:

1.

5. The flexible magnetic sheet of claim 1, wherein, The samarium iron nitride magnetic powder is obtained by surface treatment of samarium iron nitride raw magnetic powder, and has an oxide protective film on the surface, and the thickness of the oxide protective film is 0.01-0.03 μm; and / or, In the samarium iron nitride magnetic powder, the content of samarium metal is 18-24%, and the phase structure of the samarium iron nitride magnetic powder is 2:17 phase and / or 1:9 phase; and / or, The flexible magnetic sheet comprises a magnetic sheet body and a coating layer, the coating layer is coated on the outer surface of the magnetic sheet body, the material of the coating layer is medical-grade fluororubber, the thickness of the coating layer is 0.01-0.03 mm, and the weight ratio of the coating layer to the flexible magnetic sheet is 1:(10-15); and / or, The coercive force of the flexible magnetic sheet is ≥8 kOe, the magnetic decay rate is ≤5% / 30 times, and the elongation at break is ≥15%.

6. A method of producing the flexible magnetic sheet according to any one of claims 1 to 5, characterized by, The preparation method comprises: Step S1, taking the pretreated samarium iron nitride magnetic powder into a high-speed mixer for dispersion treatment, adding a coupling agent solution for solidification treatment, and then mixing the binder, the lubricant, and the heat stabilizer for mixing treatment to obtain a mixture; Step S2, taking the mixture for successively pressure rolling, radian memory plasticizing, and cutting treatment to obtain the flexible magnetic sheet.

7. The preparation method according to claim 6, characterized in that, The pretreated samarium iron nitride magnetic powder is obtained by vacuum drying at 80°C for 2-3 h; and / or, The dispersion treatment is performed at room temperature, and the treatment time is 5-30 min; and / or, The coupling agent solution is a coupling agent solution diluted by a diluent, and the diluent is ethanol; And / or, The solidification treatment is performed at a temperature of 70-90°C for 1-3 h, and the stirring speed is 800-1200 rpm; and / or, After the solidification treatment, the solidification-treated material is naturally cooled to room temperature and then screened by a screen mesh before the mixing treatment.

8. The production method according to claim 6, characterized by, In Step S2, the temperature for the pressure rolling treatment is 100-130°C, and the thickness of the material after the pressure rolling treatment is 0.1-0.4 mm; And / or, The arc memory plastic treatment includes: placing the calendered material in an arc-shaped mold, and pressurizing to 10-20 kg / cm at 100-110 ℃ 2 After 5-20 min of treatment, natural cooling is performed to obtain the arc memory plastic treated material; And / or, The temperature for the mixing treatment is 80-100°C.

9. An artificial eyelash comprising an artificial eyelash body, a flexible magnetic sheet, and a composite adhesive, characterized in that, The flexible magnetic sheet is the flexible magnetic sheet of any one of claims 1 to 6, or the flexible magnetic sheet obtained by the preparation method of the flexible magnetic sheet of claim 7 or 8.

10. The false eyelash of claim 9, wherein, The false eyelash body is obtained by chemically sharpening the original false eyelash body, and the weight of the false eyelash body is reduced by 30% compared with the weight of the original false eyelash body; and / or, The composite adhesive comprises, in terms of weight percentage, 25-35 parts of hydroxyethyl methacrylate, 15-20 parts of silicone-modified polyurethane, 10-15 parts of C5 hydrogenated petroleum resin, 5-8 parts of nano-silicon dioxide, 1.5-2.5 parts of an initiator, 0.3-0.8 parts of a leveling agent, 0.1-0.3 parts of an antioxidant, and a residual amount of acetic acid; and / or, The weight of the samarium iron nitride magnetic powder accounts for 55-70% of the weight of the false eyelash; and / or, The preparation method of the false eyelash comprises: coating the composite adhesive on the outer surface of the flexible magnetic sheet, and attaching the fish-silk line at the root of the false eyelash body material to the outer surface of the flexible magnetic sheet to obtain the false eyelash; and / or, The fish-silk line at the root of the false eyelash body material is a biomimetic fiber, and the diameter of a single biomimetic fiber is 30-50 μm; and / or, The composite adhesive is coated on the outer surface of the flexible magnetic sheet, the diameter of the adhesive point on which the composite adhesive is coated is ≤0.5 mm, and the spacing is 2-3 mm; and / or, The viscosity of the composite adhesive is 1500-2500 Pa·S at 25℃, and the amount of the composite adhesive applied is 0.005-0.1 mL / cm 2 .

Images