A Hair Transplant Fixing and Reinforcing Soft Pad Material and Its Application in Plush Toys

Abstract

This invention discloses a soft pad material for hair transplant fixation and reinforcement, and its application in plush toys. It belongs to the technical field of soft pad materials. The soft pad material provided by this invention includes a polyester fiber mesh and a soft material wrapped around the surface of the polyester fiber mesh. The soft material includes at least one of PVC, TPU, TPE, rubber, silicone, and their composites. The polyester fiber mesh is obtained by polymerizing a diacid monomer and an ethylene glycol monomer in a molar ratio of 1:(1.2-1.5). The diacid monomer, by molar part, includes 30-50 parts of semi-aromatic diacid, 40-60 parts of terephthalic acid, and 5-10 parts of 3-3'-bipyridine-5.5'-dicarboxylic acid. The soft pad provided by this invention achieves efficient reinforcement of the soft material through the polyester fiber mesh, balancing the material's flexibility and mechanical properties, enabling the soft pad to meet high pull-out force while also possessing excellent puncture resistance.

Description

Technical Field

[0001] This invention relates to the field of soft pad material technology, specifically to a soft pad material for hair transplant fixation and reinforcement and its application in plush toys. Background Technology

[0002] Currently, there are two main technical methods for fixing wigs on toy dolls: one is the PVC doll hair implantation process, which uses a hair implantation machine to insert hair strands into PVC material (such as Barbie dolls), relying on the mechanical binding force of the PVC to hook the base layer; the other is the wig attachment process, which glues the entire wig to the surface of the doll's head. However, neither of these methods can be applied to plush toys, mainly because the main body of plush toys is made of woven fabric stitched together and filled with cotton, and the fabric's resistance to deformation is insufficient; the hair implantation machine's hook cannot effectively hook the base layer on the thin fabric layer (the measured base layer slippage rate is >90%), resulting in a wig pull-out force ≤5N, far below the toy safety standard (ASTM F963 requires ≥15N), thus preventing the realization of high-density, curved surface hair implantation and other refined designs, severely restricting product development. However, no related materials have been developed in the current technology. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, the present invention provides a soft pad material for hair transplant fixation and reinforcement and its application in plush toys. The soft pad provided by the present invention achieves efficient reinforcement of soft materials through polyester fiber mesh, balances the flexibility and mechanical properties of the material, and makes the soft pad have good puncture performance while meeting the requirements of high pull-out force.

[0004] The purpose of this invention is to provide a soft pad material for hair transplant fixation and reinforcement, comprising a polyester fiber mesh and a soft material wrapped around the surface of the polyester fiber mesh. The soft material includes at least one of PVC, TPU, TPE, rubber, silicone, and their composites. The polyester fiber mesh is obtained by polymerizing a diacid monomer and an ethylene glycol monomer in a molar ratio of 1:(1.0–1.5). The diacid monomer, by molar part, comprises 20–90 parts of a semi-aromatic diacid, 0–50 parts of terephthalic acid, and 10–30 parts of 3,3'-bipyridine-5,5'-dicarboxylic acid. The structural formula of the semi-aromatic diacid is shown in Formula 1.

[0005]

[0006] In one specific embodiment, the Shore hardness of the flexible pad is 15-70A.

[0007] In one specific embodiment, the thickness of the flexible pad is 0.5 mm to 6 mm.

[0008] In one specific embodiment, the method for preparing the semi-aromatic diacid is as follows:

[0009] S1. Add p-hydroxyphenylacetic acid and methanol to a reaction vessel, add concentrated sulfuric acid or p-toluenesulfonic acid as a catalyst, and then reflux at 65-80°C for 12-16 hours; after purification, intermediate A is obtained.

[0010] S2. Under anhydrous and oxygen-free conditions, intermediate A obtained in S1, N-glycidyl phthalimide, catalyst, and solvent are added to a reaction vessel, and the mixture is stirred at 80–120°C for 12–24 hours to carry out a ring-opening reaction. After purification, intermediate B is obtained. The catalyst is at least one of triethylamine or pyridine, and the solvent is at least one of DMF or DMSO.

[0011] S3. Add intermediate B obtained in S2, lithium hydroxide, and solvent to a reaction vessel and hydrolyze at room temperature for 1-2 hours. After purification, intermediate C is obtained. The solvent is a mixed solution of tetrahydrofuran and water.

[0012] S4. Under anhydrous and oxygen-free conditions, the intermediate C obtained in S3, succinic anhydride, catalyst, and solvent are added to a reaction vessel, and the temperature is slowly raised to 40-80°C to allow the succinic anhydride to undergo ring-opening reaction for 4-8 hours. After purification, a semi-aromatic diacid is obtained. The catalyst is 4-dimethylaminopyridine, and the solvent is anhydrous dichloromethane.

[0013] In one specific embodiment, the polyester is prepared as follows: diacid and diol are added to a reaction vessel in a certain proportion, stirred evenly, and then heated to 170-190°C for esterification reaction. The reaction lasts for 8-10 hours. When the acid value drops to 50-80 mg KOH / g, the esterification reaction is considered to be basically completed. The reaction temperature is gradually increased to 260-280°C, and the vacuum system is started simultaneously to slowly reduce the pressure inside the reaction vessel to below 10 Pa for polycondensation reaction. When the intrinsic viscosity reaches 0.35-0.8 dL / g, the reaction is stopped, nitrogen gas is introduced to atmospheric pressure, and the molten polyester is extruded through a gear pump, granulated by a pelletizer, and dried to obtain polyester chips.

[0014] In one specific embodiment, the polyester fiber web is prepared by:

[0015] S1. The polyester chips are fed into a screw extruder and melted into a uniform melt at 250-290℃, and impurities are removed by a melt filter;

[0016] S2. The melt enters the spinning box and is extruded through the spinneret to form a continuous melt stream. The stream immediately enters the side-blowing cooling zone and is quickly solidified into polyester filament. The solidified filament enters the airflow drawing device for stretching and refining, with a draw ratio of 5-10 times, reducing the fiber fineness to 1-3D.

[0017] S3. The drawn continuous filaments are evenly spread on a moving mesh screen by a web-laying machine to form an oriented fiber layer. The fiber layer is fed into a preliminary hot press roller system. The hot pressing parameters are set to a temperature of 160-180℃ and a pressure of 0.4-0.6MPa. After hot pressing, a preliminary cured fiber web is obtained. A ZnCl2 mother liquor with a concentration of 0.1-0.5mol / L is prepared in an immersion tank. NaOH solution is added to adjust the pH to 6.0. The continuous preliminary cured fiber web is fed into the ZnCl2 immersion tank through guide rollers and completely immersed at 25℃-35℃. It is ultrasonically soaked for 30-60 minutes. After soaking, the fiber web is first drained by a draining rack, then washed by a series of deionized water washing tanks, and drained again.

[0018] S4. The Zn ion crosslinked fiber web is fed into a final heat setting oven with nitrogen protection. It is heated by hot rollers at 200℃~220℃ and 0.5-2MPa pressure to locally melt and bond the fiber cross-sections, thus obtaining a polyester fiber web.

[0019] The present invention also protects the preparation method of the hair transplant fixation and reinforcement soft pad material, which includes the following steps: molding a polyester fiber mesh with at least one soft material of PVC, TPU, TPE, rubber, silicone and their composites through slush molding, injection molding or compression molding process to obtain the soft pad material.

[0020] In one specific embodiment, the slush molding process involves pouring molten soft material into a mold pre-placed with a polyester fiber web, rotating it to ensure the material adheres evenly to the surface and interior of the fiber web, and cooling it to obtain a soft gasket material. The injection molding process involves injecting molten soft material under high pressure into the mold cavity pre-placed with a polyester fiber web, allowing the material to penetrate the fiber web and then cool and solidify, forming a soft gasket material with a "fiber-matrix" interlocking structure. The compression molding process involves alternately laying soft material and polyester fiber web into a mold, heating and pressurizing it to crosslink and solidify the matrix, while simultaneously bonding it tightly with the fiber web to obtain the soft gasket material.

[0021] Another object of the present invention is to protect a plush toy, comprising a plush toy body made of textile fabric and a stuffing, wherein the hair transplantation area of ​​the plush toy body is fixed with the aforementioned hair transplantation fixing and reinforcing soft pad material, and a continuous interface layer is formed between the bonding surface of the hair transplantation fixing and reinforcing soft pad material and the inner wall of the toy, wherein the continuous interface layer is a hot melt adhesive layer, a silicone layer, a polyurethane adhesive layer or a stitch.

[0022] Another object of the present invention is to protect a hair transplantation process for a plush toy, comprising: setting the aforementioned hair transplantation fixation and reinforcement soft pad material in the hair transplantation area on the inner wall of the plush toy; using a hair transplantation machine to puncture the fabric and the hair transplantation fixation and reinforcement soft pad, so that the bottom line of the suture forms a firm hair transplantation knot inside the hair transplantation fixation and reinforcement soft pad; and achieving a hair transplantation density ≥ 80 clusters / cm².2 The pull-out force of a single cluster is ≥15N.

[0023] Beneficial effects

[0024] This invention provides a soft pad material for hair transplant fixation and reinforcement, comprising a polyester fiber mesh and a soft material wrapped around the surface of the polyester fiber mesh. The soft material includes at least one of PVC, TPU, TPE, rubber, silicone, and their composites. The polyester fiber mesh provides rigid support for the soft material. The low hardness of the soft material and the three-dimensional porous structure of the polyester fiber mesh ensure easy needle insertion for sutures, while the high strength of the polyester fiber mesh improves the pull-out force of individual hair follicles, achieving a balance between ease of operation and product quality.

[0025] This invention uses semi-aromatic diacids, terephthalic acid, and 3-3'-bipyridine-5,5'-dicarboxylic acid as diacid monomers for polyester materials. The introduction of semi-aromatic diacids disrupts the rigid structure of the terephthalic acid and ethylene glycol molecular chains, reducing their crystallinity and improving the softness of the polyester fibers, thus preventing damage to the feel of plush toys and increasing the puncture resistance of soft materials. Furthermore, the phthalimide groups in the semi-aromatic diacids improve the heat resistance of the polyester fibers, compensating for the decrease in heat distortion temperature caused by the disruption of the rigid structure in the polyester molecular chains, making it suitable for the processing temperatures of materials such as PVC, TPU, TPE, rubber, and silicone. Finally, the introduction of bipyridine groups increases the polarity of the polyester, improving its compatibility with polar soft materials such as TPU and PVC. Zinc chloride is used as a post-treatment during the polyester fiber web formation process. Zinc ions and bipyridine can form metal-ion ligand coordination crosslinks, thereby increasing the strength of the polyester fibers and further improving the pull-out force of hair transplants. Attached Figure Description

[0026] Figure 1 This is a structural diagram showing the connection between the hair transplant fixation and reinforcement soft pad material and the hair transplant area in this invention through an adhesive layer;

[0027] Figure 2 This is a structural diagram showing the connection between the hair transplant fixation and reinforcement soft pad material and the hair transplant area via sutures in this invention;

[0028] Figure 3 This is a schematic diagram of the synthetic route for semi-aromatic diacids;

[0029] Figure 4 The 1H NMR spectrum of a semi-aromatic diacid;

[0030] Among them: hair transplant fixation and reinforcement soft pad 10, plush toy body 20, filling material 30, continuous interface layer 40, hair transplant area 201, and suture line 401. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0033] The raw materials used in the examples and comparative examples are described below:

[0034] PVC: Nan Ya Plastics, grade SE085H36, Shore hardness A 66±3 (ISO 868), elongation at break 434%;

[0035] TPU: BASF, grade S80A10, Shore hardness 80A, elongation at break 750%;

[0036] TPE: Polyvin, Dynaflex TM G2706-1000-00, Shore hardness 28A; elongation at break 660%;

[0037] Silicone: Dow Corning, Q7-4780, Shore hardness 50A;

[0038] Ethylene glycol: analytical grade, Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0039] Terephthalic acid: 99%, Guangzhou Yuanda New Materials Co., Ltd.;

[0040] 3-3'-Bipyridine-5,5'-Dicarboxylic Acid: 98%, Henan Weitixi Chemical Technology Co., Ltd.

[0041] Semi-aromatic diacid: Prepared in-house, preparation method as follows:

[0042] S1. Add 1 mol of p-hydroxyphenylpropionic acid and 10 mol of methanol to the reaction vessel as reactants and solvents, respectively. Add 0.1 mol of p-toluenesulfonic acid. Refrigerate at 70°C for 16 hours in air. Monitor the reaction progress by TLC. The developing solvent is ethyl acetate / petroleum ether = 1:3. The reaction is complete when the starting spot disappears. Add saturated sodium bicarbonate solution to neutralize the catalyst. Separate the layers. Wash the organic layer with saturated brine and dry with magnesium sulfate. Filter and collect the filtrate in a flask. Remove excess solvent by vacuum distillation. Purify by silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 1:5). Collect the target fraction and dry under vacuum to obtain intermediate A with a yield of 95%.

[0043] S2. Under a nitrogen atmosphere, 1 mol of intermediate A, 1.2 mol of N-glycidyl phthalimide, and 0.2 mol of triethylamine were dissolved in 5 L of dry DMF and added to a reaction vessel. The mixture was stirred at 90 °C under a nitrogen atmosphere for 12 hours. The reaction was stopped when the spot of intermediate A disappeared, as monitored by TLC (developing solvent: dichloromethane / methanol = 10:1). The system was cooled to room temperature and poured into an equal volume of ice water. The solid precipitated, and the precipitate was collected by filtration. The precipitate was washed three times with ice water to remove excess DMF and triethylamine. The precipitate was recrystallized from ethyl acetate / n-hexane (volume ratio 1:2) and dried under vacuum to obtain intermediate B with a yield of 80%.

[0044] S3. Add 1 mol of intermediate B, 2 mol of lithium hydroxide, and 6 L of a mixed solution of tetrahydrofuran and water (volume ratio 1:1) to the reaction vessel. Stir at 25-30°C for 2-3 hours. TLC monitoring (developing solvent: dichloromethane / methanol = 8:1) indicates complete hydrolysis when the intermediate spots disappear. Acidify the reaction solution with 1M hydrochloric acid to adjust the pH of the system to 2-3 to precipitate the product. Filter the product, collect the precipitate, wash the filter cake three times with deionized water, recrystallize with ethanol / water (volume ratio 3:1), and dry under vacuum to obtain intermediate C with a yield of 90%.

[0045] S4. Under a nitrogen atmosphere, in a dry reaction vessel, add 1 mol of intermediate C, 1.1 mol of succinic anhydride, 0.1 mol of 4-dimethylaminopyridine, and 5 L of anhydrous dichloromethane. Stir to ensure the reactants are fully mixed and dissolved. Slowly heat the reaction system to 45°C and maintain the temperature with stirring for 6 hours. Monitor by TLC (developing solvent: dichloromethane / methanol = 5:1) until the spot of intermediate C disappears, indicating the end of the reaction. Remove dichloromethane by rotary evaporation. Dissolve the residue in ethyl acetate, wash twice with 5% citric acid solution, and then wash once with saturated brine. Dry with anhydrous sodium sulfate, filter, concentrate the filtrate, and purify by silica gel column chromatography (dichloromethane:methanol = 10:1). Collect the target fraction and dry under vacuum to obtain a semi-aromatic diacid with a yield of 75%.

[0046] Using deuterated chloroform (CDCl3) as a solvent, the 1H NMR spectrum of semi-aromatic diacids was determined, such as... Figure 4 As shown in the diagram. The schematic diagram of the synthetic route for semi-aromatic diacids is shown below. Figure 3 As shown.

[0047] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0048] Preparation Example

[0049] Polyesters 1 to 6 are prepared using the following methods:

[0050] In a 5L stainless steel reactor (equipped with a stirrer, nitrogen protection, and a water separator), pretreated semi-aromatic diacid, terephthalic acid, 3,3'-bipyridine-5,5'-dicarboxylic acid, ethylene glycol, butanediol, and antimony trioxide are added sequentially and stirred until homogeneous. The mixture is stirred at 100 rpm, and nitrogen gas (flow rate 5 L / min) is introduced to purge air. The temperature is slowly raised to 180-200℃ and maintained for 2 hours. Then, the temperature is raised to 220-240℃, and the reaction continues for 3-4 hours. During this period, the generated water is collected through the water separator, and samples are taken to test the acid value (the reaction is stopped when the acid value is ≤10 mg KOH / g).

[0051] After esterification, stop the nitrogen flow, turn on the vacuum system, and gradually reduce the pressure to 5-10 kPa while raising the temperature to 250-260℃. Increase the stirring speed to 150 rpm and react for 1.5-2 hours. When the intrinsic viscosity is measured to be 0.2-0.3 dL / g, further increase the vacuum to 100 Pa and raise the temperature to 270-280℃. Reduce the stirring speed to 50-80 rpm and react for 3-5 hours, continuously removing residual diol molecules during this period. When the intrinsic viscosity of the system reaches 0.6-0.8 dL / g, stop the reaction. Introduce nitrogen into the reactor and extrude the molten polyester from the bottom outlet. After water cooling, granulate to obtain polyester chips with a diameter of 3-4 mm. Intrinsic viscosity test: According to GB / T14190-2017 "Test Methods for Intrinsic Viscosity of Fiber Grade Polyester (PET) Chips", 5.1 Test Method A, the intrinsic viscosity was measured using an Ubbelohde viscometer, with phenol / 1,1,2,2-tetrachloromethane (mass ratio 50:50) as the solvent.

[0052] Table 1. Monomer addition amount (molar parts) for polyester chips

[0053] Polyester 1 Polyester 2 Polyester 3 Polyester 4 Polyester 5 Polyester 6 semi-aromatic dicarboxylic acid 30 50 50 50 0 0 terephthalic acid 60 45 40 50 90 100 3-3'-Bipyridine-5,5'-Dicarboxylic Acid 10 5 10 0 10 0 Ethylene glycol 120 120 120 120 120 120 Intrinsic viscosity (dL / g) 0.72 0.61 0.68 0.63 0.78 0.76

[0054] Polyester fiber webs 1-6:

[0055] Polyesters 1 to 6 were dried in a vacuum drying oven at 120-140℃ for 4-6 hours to reduce the moisture content to below 0.01%.

[0056] Specifically, in the embodiments, the polyester chips were dried in a vacuum drying oven at 130°C for 5 hours to reduce the moisture content to below 0.01%.

[0057] Pre-dried polyester chips are fed into a screw extruder (single screw, length-to-diameter ratio 25-30:1, 28:1 used in the example) and melted into a homogeneous melt at 240-290°C. Impurities are removed by a melt filter (mesh size 10-20μm, 20μm used in the example).

[0058] Specifically, the barrel temperatures of the screw extruder are as follows: feed section: 240℃, compression section: 260℃, homogenization section: 285℃.

[0059] The melt enters the spinning box, where the temperature is controlled at 280-285℃. It is extruded through a spinneret (orifice diameter 0.1-0.4mm, 0.3mm is used in this example) to form a continuous melt stream. The stream immediately enters the side-blowing cooling zone and is rapidly solidified into polyester filaments at an air temperature of 20-25℃, an air velocity of 0.5-1.5m / s, and a humidity of 60%-70%. The solidified filaments are then drawn and refined by an airflow drawing device with a draw ratio of 3-10 times, reducing the fiber fineness to 1-3D to obtain polyester fibers.

[0060] Specifically, the wind temperature is 22℃, the wind speed is 1.2m / s, the relative humidity is 65%, the draw ratio is 8 times, and the fiber fineness is 1.2D.

[0061] The drawn continuous filaments are evenly spread onto a moving mesh screen using a web-laying machine, forming an oriented fiber layer with a thickness of 2 mm and an areal density of 80 g / m². 2 The fiber layer is fed into the preliminary hot press roller system. The hot press parameters are set as follows: temperature 170℃, pressure 0.4MPa, and roller speed 1.2m / min. After hot pressing, a preliminary cured fiber web is obtained.

[0062] Prepare a 0.1 mol / L ZnCl2 mother liquor in an immersion tank, add 1 mol / L NaOH solution to adjust the pH to 6.0, and feed the continuous pre-cured fiber web into the ZnCl2 immersion tank through guide rollers. It is completely immersed at 25°C and ultrasonically immersed for 45 minutes with an ultrasonic power of 400W, ultrasonically for 5 minutes every 15 minutes, and a traction speed of 0.5 m / min. After immersion, the fiber web is first drained through a draining rack, then washed through a series of deionized water washing tanks, and drained again.

[0063] During the soaking process, 2 mL of solution was taken every 10 minutes, and the absorbance at 340 nm was measured using UV-Vis. When the absorbance dropped from the initial value to below 0.3, it indicated that the Zn concentration in the solution had decreased. 2+ It has already coordinated extensively with pyridine on the fiber, and a freshly prepared ZnCl2 solution needs to be added.

[0064] At least three deionized water washing tanks are connected in series. The first tank is stirred and washed at room temperature for 15 minutes, the second tank is ultrasonically washed at room temperature for 10 minutes with a power of 300W, and the third tank is settled and washed at room temperature for 10 minutes. The pH of the effluent is tested with pH test paper and found to be consistent with the pH of the influent, proving that there is no residual ZnCl2.

[0065] The Zn ion crosslinked fiber web is fed into a final heat setting oven with nitrogen protection and heated by hot rollers for 40 minutes at 150-200℃ and 0.5MPa pressure to locally melt and bond the fiber cross-sections. After cooling, polyester fiber webs 1-6 are obtained.

[0066] The temperature control process involves preheating at 150℃ for 10 minutes, maintaining a constant temperature at 200℃ for 20 minutes, and cooling down at 180℃ for 10 minutes.

[0067] Polyester fiber web 7: Compared with polyester fiber web 1, the difference is that it is not soaked in ZnCl2 and washed with deionized water.

[0068] The following performance tests were conducted on polyester fibers and polyester fiber webs 1-7, and the results are shown in Table 2:

[0069] (1) Breaking strength of monofilament: The breaking strength of the long fiber was tested according to GB / T 14344-2022 Test method for tensile properties of chemical fiber filament. The speed of the moving clamp was 100 mm / min, the width of the sample was 50 mm, and the initial clamping distance was 200 mm.

[0070] (2) Tensile strength and elongation at break: The tensile strength and elongation at break of polyester fiber web were tested in accordance with the standard GB / T 3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)".

[0071] Table 2 Mechanical properties of polyester fibers and polyester fiber webs

[0072]

[0073] Examples and Comparative Examples

[0074] Example 1

[0075] PVC flexible gaskets are molded using a slush molding process, and the manufacturing method is as follows:

[0076] Cut the polyester fiber mesh 1 to the mold size, leaving a 5-10mm margin at the edges. Preheat the mold to 150-180℃. Fix the cut polyester fiber mesh to the inner wall of the mold with high-temperature resistant glue, ensuring the mesh surface is flat and wrinkle-free. Mix 100 parts PVC resin, 60 parts citrate ester plasticizer and 3 parts calcium zinc heat stabilizer, and stir until there are no particles. Pour the mixture into the mold in which the polyester fiber mesh has been placed. Close the mold and rotate it at 10-20 rpm to make the PVC paste evenly adhere to the surface and inside of the fiber mesh. Heat the mold to 160℃ and keep it at that temperature for 10-15 minutes. Cool it down to below 60℃ and open the mold. After cooling, remove the flash to obtain a PVC soft gasket with a thickness of 3mm.

[0077] Example 2

[0078] TPU flexible pads are manufactured using injection molding, and the manufacturing method is as follows:

[0079] Place the cut polyester fiber mesh 1 into the mold cavity and fix it with positioning pins. Control the mold temperature at 40-60℃, melt the TPU, and then inject it into the mold through an injection molding machine. The injection molding machine screw diameter is 25-35mm, the barrel temperature is 170℃ in zone 1, 190℃ in zone 2, and 200-210℃ in zone 3, the injection pressure is 80-120MPa, the injection speed is 30-50mm / s, the holding pressure is 50-70MPa, and the holding time is 5-10s. Cool to 60℃, demold, remove the gate, and obtain a TPU soft gasket with a thickness of 3mm.

[0080] Example 3

[0081] The TPE soft gasket is molded by injection molding. The difference between the preparation method and Example 2 is that the TPU material is replaced with TPE.

[0082] Example 4

[0083] Silicone flexible gaskets are molded using a compression molding process, and the preparation method is as follows:

[0084] Mix 100 parts of raw silicone rubber, 2 parts of vulcanizing agent (bis(2,5) vulcanizing agent), and 5 parts of reinforcing agent (silica) evenly on a two-roll mill at a temperature <50℃, producing a sheet thickness of 1mm. Apply a release agent to the mold surface and preheat to 100-120℃. Lay a layer of silicone sheet as the bottom layer, a layer of polyester fiber mesh 1 in the middle, and another layer of silicone sheet on top. Close the mold, set the pressure to 10-20MPa, the temperature to 160-180℃, and the vulcanization time to 10-20min. Open the mold, remove the product, remove the burrs, and obtain a soft silicone gasket with a thickness of 3.5mm.

[0085] Example 5

[0086] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with polyester fiber mesh 2.

[0087] Example 6

[0088] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with polyester fiber mesh 3.

[0089] Comparative Example 1

[0090] The PVC flexible gasket differs from Example 1 in that it does not contain polyester fiber mesh 1;

[0091] Comparative Example 2

[0092] The TPU soft pad differs from Example 2 in that it does not contain polyester fiber mesh 1;

[0093] Comparative Example 3

[0094] The TPE soft gasket, compared with Example 3, differs in that it does not contain polyester fiber mesh 1;

[0095] Comparative Example 4

[0096] The silicone soft pad differs from that in Example 4 in that it does not contain polyester fiber mesh 1;

[0097] Comparative Example 5

[0098] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with polyester fiber mesh 4.

[0099] Comparative Example 6

[0100] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with the polyester fiber mesh 5.

[0101] Comparative Example 7

[0102] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with the polyester fiber mesh 6.

[0103] Comparative Example 8

[0104] The silicone soft pad differs from Example 4 in that the polyester fiber mesh 1 is replaced with the polyester fiber mesh 7.

[0105] The soft gaskets of the examples and comparative examples were subjected to the following performance tests, and the results are shown in Table 3.

[0106] (1) Shore hardness: The Shore hardness A of the soft gaskets in the examples and comparative examples was tested with reference to the standard ISO 868-2003 "Determination of indentation hardness using hardness testers for plastics and hard rubber".

[0107] (2) Maximum puncture force: Using a puncture force tester, the soft pad was cut into 50mm×50mm samples. The probe was replaced with a Φ4mm stainless steel rod with a 60° conical tip and a tip radius of 0.8mm. The soft pad material was clamped in a fixture with a 10mm thick cork with a Φ40mm central hole underneath. The probe was inserted into the soft pad at a speed of 100mm / min. The sensor recorded the maximum puncture force. Each material was tested 10 times, and the average value was taken. The test temperature was 23±2℃ and the humidity was 50±5%RH.

[0108] (3) Pull-out force: In the head area of ​​the plush toy with a fixed soft pad, an automatic hair transplant machine was used to perform hair transplantation. The needle of the hair transplant machine penetrated the head fabric of the plush toy body 20 in sequence, and the hair transplant fixing and reinforcing soft pad 10 in sequence. After exiting, it hooked the bottom line to form a firm knot. The pull-out force of a single clump of hair was tested using a universal tensile testing machine at a speed of 50 mm / min.

[0109] (4) Pull-off fatigue test: Use a universal tensile testing machine to perform 5000 repeated pull-off tests with a tensile force of 15N and a speed of 50mm / min, and record whether the thread breaks off.

[0110] Table 3 Mechanical property tests of flexible gaskets

[0111]

[0112]

[0113] The results from the examples and comparative examples show that the soft pad material for hair transplant fixation and reinforcement made of polyester fiber mesh and soft material has good puncture resistance (maximum puncture force <2N is considered easy to puncture) and anti-pull-out effect. It can withstand pull-out tests of more than 5000 without detachment, which meets the requirements for hair transplant fixation and reinforcement in plush toys.

[0114] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A soft pad material for hair transplant fixation and reinforcement, characterized in that, The invention comprises a polyester fiber web and a flexible material wrapped around the surface of the polyester fiber web. The flexible material includes at least one of PVC, TPU, TPE, rubber, silicone, and their composites. The polyester fiber web is obtained by polymerizing a diacid monomer and an ethylene glycol monomer in a molar ratio of 1:(1.2~1.5). The diacid monomer, by molar part, comprises 30~50 parts of a semi-aromatic diacid, 40~60 parts of terephthalic acid, and 5~10 parts of 3-3'-bipyridine-5.5'-dicarboxylic acid. The structural formula of the semi-aromatic diacid is shown in Formula 1. Formula 1.

2. The soft pad material for hair transplant fixation and reinforcement as described in claim 1, wherein the Shore hardness of the soft pad is 15-70A.

3. The soft pad material for hair transplant fixation and reinforcement as described in claim 1, characterized in that, The thickness of the soft pad is 0.5mm to 6mm.

4. The soft pad material for hair transplant fixation and reinforcement as described in claim 1, characterized in that, The preparation method of the semi-aromatic diacid is as follows: S1. Add p-hydroxyphenylacetic acid and methanol to a reaction vessel, add concentrated sulfuric acid or p-toluenesulfonic acid as a catalyst, and then reflux at 65~80℃ for 12~16 hours. After purification, intermediate A is obtained. S2. Under anhydrous and oxygen-free conditions, intermediate A obtained in S1, N-glycidyl phthalimide, catalyst and solvent are added to a reaction vessel and stirred at 80~120℃ for 12~24 hours to carry out a ring-opening reaction. After purification, intermediate B is obtained. S3. Add intermediate B obtained in S2, lithium hydroxide and solvent to the reaction vessel, and hydrolyze at room temperature for 1-2 hours. After purification, intermediate C is obtained. S4. Add intermediate C obtained in S3, succinic anhydride, catalyst and solvent to the reaction vessel, slowly heat to 40~80℃, and allow the succinic anhydride to undergo ring-opening reaction for 4~8 hours. After purification, a semi-aromatic diacid is obtained.

5. The soft pad material for hair transplant fixation and reinforcement as described in claim 1, characterized in that, The polyester is prepared as follows: diacid, diol, and catalyst are added to a reaction vessel in a specific ratio, stirred evenly, and then heated to 180-200℃ and held for 2 hours. The temperature is then increased to 220-240℃, and the reaction continues for 3-4 hours. When the acid value drops below 10 mg KOH / g, the reaction temperature is gradually increased to 250-280℃. Simultaneously, a vacuum system is activated, and the pressure inside the reaction vessel is slowly reduced to below 5-10 kPa. The reaction continues for 1.5-2 hours. When the intrinsic viscosity reaches 0.2-0.3 dL / g, the vacuum level is further increased to 100 Pa, and the temperature is increased to 270-280℃. The reaction continues for 3-5 hours. When the intrinsic viscosity of the system reaches 0.6-0.8 dL / g, the reaction is stopped. Nitrogen gas is introduced to atmospheric pressure, and the molten polyester is extruded through a gear pump, granulated by a pelletizer, and dried to obtain polyester chips.

6. The soft pad material for hair transplant fixation and reinforcement as described in claim 1, characterized in that, The method for preparing the polyester fiber web is as follows: S1. The pre-dried polyester chips are fed into a screw extruder and melted into a uniform melt at 240-290℃, and impurities are removed by a melt filter; S2. The melt enters the spinning box and is extruded through the spinneret to form a continuous melt stream. The stream immediately enters the side-blowing cooling zone and is quickly solidified into polyester filament. The solidified filament enters the airflow drawing device for stretching and refining, with a draw ratio of 3-5 times, reducing the fiber fineness to 1-3D. S3. The drawn continuous filaments are evenly spread on a moving mesh screen by a web-laying machine to form an oriented fiber layer. The fiber layer is fed into a preliminary hot press roller system. The hot pressing parameters are set to a temperature of 160~180℃ and a pressure of 0.4~0.6MPa. After hot pressing, a preliminary cured fiber web is obtained. A ZnCl2 mother liquor with a concentration of 0.1~0.5mol / L is prepared in an immersion tank. NaOH solution is added to adjust the pH to 6.

0. The continuous preliminary cured fiber web is fed into the ZnCl2 immersion tank through guide rollers and completely immersed at 25℃~35℃. It is ultrasonically soaked for 30~60 minutes. After soaking, the fiber web is first drained by a draining rack, then washed by a series of deionized water washing tanks, and drained again. S4. The Zn ion crosslinked fiber web is fed into a final heat setting oven with nitrogen protection, and heated by hot rollers at 200℃~220℃ and 0.5-2MPa pressure to locally melt and bond the fiber cross-sections, thus obtaining a polyester fiber web.

7. The method for preparing the soft pad material for hair transplant fixation and reinforcement as described in any one of claims 1 to 6, characterized in that, A soft gasket material is prepared by molding a polyester fiber mesh with at least one soft material, such as PVC, TPU, TPE, rubber, silicone, or their composites, through slush molding, injection molding, or compression molding processes.

8. The method for preparing the hair transplant fixation and reinforcement soft pad material as described in claim 7, characterized in that, The slush molding process involves pouring molten soft material into a mold pre-placed with a polyester fiber mesh, rotating it to ensure the material adheres evenly to the surface and interior of the fiber mesh, and then cooling to obtain a soft gasket material. The injection molding process involves injecting molten soft material under high pressure into the mold cavity pre-placed with a polyester fiber mesh, allowing the material to penetrate the fiber mesh and then cool and solidify, forming a soft gasket material with an interlocking "fiber-matrix" structure. The compression molding process involves alternately layering soft material, polyester fiber mesh, and soft material into a mold, heating and pressurizing it to crosslink and solidify the matrix, while simultaneously bonding it tightly with the fiber mesh to obtain a soft gasket material.

9. A plush toy, comprising a plush toy body made of textile fabric and stuffing, characterized in that: The hair transplant area of ​​the plush toy body is fixed with a hair transplant fixation and reinforcement soft pad material as described in any one of claims 1 to 6, and the bonding surface of the hair transplant fixation and reinforcement soft pad material forms a continuous interface layer with the inner wall of the toy, wherein the continuous interface layer is a hot melt adhesive layer, a silicone layer, a polyurethane adhesive layer or a stitch.

10. A hair transplantation process for a plush toy, characterized in that, include: The hair transplant area on the inner wall of the plush toy is provided with the hair transplant fixation and reinforcement soft pad material as described in any one of claims 1 to 6; the hair transplant machine is used to puncture the fabric and the hair transplant fixation and reinforcement soft pad, so that the bottom line of the suture line forms a firm hair transplant knot inside the hair transplant fixation and reinforcement soft pad; the hair transplant density is ≥80 clusters / cm², and the pull-out force of a single cluster is ≥15N.

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