A pickleball paddle

Abstract

The application provides a pickleball racket, and relates to the technical field of pickleball rackets.The pickleball racket provided by the application comprises a polypropylene foamed inner core and a polypropylene shell covering the foamed inner core, the foamed inner core and / or the polypropylene shell forms a handle part, the handle part is sleeved with a TPE handle sleeve, and the surface of the polypropylene shell is provided with a self-defined pattern formed by laser engraving; the polypropylene shell is made of modified polypropylene material after injection molding and solidification, the modified polypropylene material comprises polypropylene resin and laser engraving powder dispersed in the polypropylene base material, and the laser engraving powder comprises at least one of nano-aluminum oxide and modified nano-aluminum oxide.The pickleball racket provided by the application adopts recyclable polypropylene material, which can effectively improve the environmental protection of the pickleball racket, and the addition of laser engraving powder in the polypropylene shell can effectively improve the laser engraving effect.

Description

Technical Field

[0001] This invention relates to the field of Peak racket technology, and more particularly to a Peak racket. Background Technology

[0002] Pickleball is a racket sport that combines features of tennis, badminton, and table tennis. Its popularity stems from its small court requirements, slow ball speed, ease of learning, high level of fun, and strong social aspect, making it a favorite among people of all ages. As the core equipment for player-ball interaction, the structure and materials of the pickle racket directly impact its hitting performance and feel. Currently, commonly used rackets primarily employ a multi-layered composite structure, including an inner honeycomb core layer and a racket face surrounding it. The honeycomb core layer directly affects the racket's touch hardness and power feedback, while the racket face provides the hitting feel and control.

[0003] In modern manufacturing processes, laser marking technology has become an important part of Peak racket production. By using a high-energy laser beam to precisely etch brand logos, model information, and decorative patterns onto the racket face, not only can permanent markings be achieved to prevent detachment and wear, but also the fine graphics and text can enhance product recognition and high-end texture. This non-contact processing method has the advantages of being environmentally friendly and efficient, meeting the needs of modern intelligent manufacturing, while avoiding the introduction of textured paint on the racket surface, thus meeting Peak racket standards.

[0004] However, when recyclable polypropylene (PP) material is used for the marking surface, the low absorption rate of PP for commonly used industrial laser wavelengths makes it difficult to induce an effective color development reaction, resulting in a severe lack of contrast in the marked pattern. Specifically, the markings appear as blurry, light white traces instead of clear, dark images, with melting and diffusion at the edges, and fine details cannot be accurately reproduced. Therefore, there is an urgent need to provide a solution to improve these problems. Summary of the Invention

[0005] The purpose of this invention is to provide a Peak racket that uses recyclable polypropylene material, which can effectively improve the environmental friendliness of Peak rackets. At the same time, adding laser engraving powder to the polypropylene shell can effectively improve the laser engraving effect.

[0006] The present invention provides a Peak racket, comprising a polypropylene foamed inner core and a polypropylene outer shell covering the foamed inner core. The foamed inner core and / or the polypropylene outer shell form a handle portion, the handle portion is fitted with a TPE grip sleeve, and the surface of the polypropylene outer shell has a custom pattern formed by laser engraving. The polypropylene outer shell is made of modified polypropylene material by injection molding and curing. The modified polypropylene material includes polypropylene resin and laser engraving powder dispersed in the polypropylene substrate. The laser engraving powder includes at least one of nano-alumina and modified nano-alumina.

[0007] Optionally, the shell has a face that contacts and strikes the pickle.

[0008] Optionally, the polypropylene shell includes a first shell and a second shell that are symmetrically spliced ​​together, and both the first shell and the second shell are formed by injection molding. The first shell and the second shell are fixed by snap-fitting and / or laser welding.

[0009] Optionally, the TPE gloves have sweat-wicking grooves or sweat-wicking holes on their outer surface, and friction stripes are also provided on the outer side of the gloves.

[0010] Optionally, the modified nano-alumina includes an alumina core and a mesoporous silica layer covering the surface of the alumina core, and the mesoporous silica layer is doped with neodymium oxide nanoparticles.

[0011] Optionally, the method for preparing the modified nano-alumina includes: hydrolyzing and condensing nano-alumina with a mesoporous template on its surface in a mixed solution containing tetraethyl orthosilicate and neodymium ions, followed by drying, calcination, and surface silane activation to obtain modified nano-alumina.

[0012] Optionally, the method for preparing the modified nano-alumina includes the following steps: wetting nano-alumina in a mesoporous template solution to obtain a mixed suspension; dissolving neodymium salt in the mixed suspension by stirring, adding tetraethyl orthosilicate in an alkaline environment for hydrolysis and condensation, and then separating the composite material; drying, calcining, and surface silane activation of the composite material to obtain modified nano-alumina.

[0013] Optionally, the mesoporous template agent in the mesoporous template solution includes one of tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, and octadecyltrimethylammonium bromide.

[0014] Optionally, the average particle size of the nano-alumina is 10nm-50nm.

[0015] Optionally, the nano-alumina includes one of α-Al2O3 and γ-Al2O3.

[0016] Optionally, the mass ratio of the nano-alumina to the mesoporous template agent in the mesoporous template solution is 1:(0.1-0.3).

[0017] Optionally, immersion can be performed at an ultrasonic power of 200W-800W.

[0018] Optionally, it can be immersed at 50℃-70℃.

[0019] Optionally, soak for 1-3 hours.

[0020] Optionally, the neodymium salt includes one of neodymium nitrate, neodymium acetate, and neodymium chloride.

[0021] Optionally, after the neodymium salt is dissolved in the mixed suspension, the mass ratio of neodymium ions to the nano-alumina is (0.3-0.5):1.

[0022] Optionally, the neodymium salt is added to the mixed suspension and then dissolved by ultrasonication.

[0023] Optionally, ammonia can be added to adjust the mixed suspension to an alkaline environment.

[0024] Alternatively, an ethanol solution of tetraethyl orthosilicate can be added dropwise in an alkaline environment.

[0025] Alternatively, the neodymium salt can be dissolved by stirring in a mixed suspension at 50°C-70°C.

[0026] Optionally, the mixing ratio of the tetraethyl orthosilicate to the nano-alumina is 0.5 mL / g to 2 mL / g.

[0027] Optionally, tetraethyl orthosilicate is added at 50℃-70℃ for hydrolysis.

[0028] Optionally, after adding tetraethyl orthosilicate, the mixture is sonicated for 12-24 hours.

[0029] Optionally, after hydrolysis and condensation, the bottom precipitate is separated by centrifugation at 400×g-500×g.

[0030] Optionally, the product can be washed with an ethanol-water mixture after separation.

[0031] Optionally, the composite material has an alumina-based core formed of nano-silica and a nano-silica gel layer wrapped around the surface of the alumina-based core, wherein the nano-silica gel layer is doped with neodymium ions.

[0032] Optionally, drying can be carried out at 80℃-100℃.

[0033] Alternatively, drying can be performed in a vacuum environment.

[0034] Alternatively, calcination can be carried out in an oxygen-containing atmosphere.

[0035] Optionally, calcination can be carried out at 500℃-600℃.

[0036] Optionally, calcination can be carried out for 3-6 hours.

[0037] Optionally, a silane coupling agent is used for surface silane activation, wherein the silane coupling agent includes one of KH-550, KH-560, and KH570, and the mass ratio of the silane coupling agent to the dried and calcined composite material is (0.1-0.2):1.

[0038] Optionally, the modified polypropylene material, by weight, comprises: 70-80 parts polypropylene resin, 3-6 parts compatibilizer, 0.1-0.5 parts lubricant, 0.3-0.6 parts antioxidant, 3-5 parts toughening agent, 0.1-0.3 parts light stabilizer, 0.1-0.3 parts nucleating agent, and 1-2 parts laser engraving powder.

[0039] Optionally, the melt index of the polypropylene resin is 40 g / 10 min to 50 g / 10 min.

[0040] Optionally, the polypropylene resin includes one of copolymer polypropylene and homopolymer polypropylene.

[0041] Optionally, the compatibilizer comprises maleic anhydride-grafted polypropylene.

[0042] Optionally, the lubricant includes one of calcium stearate and polyethylene wax.

[0043] Optionally, the antioxidant includes one of antioxidant 1010 and antioxidant 168.

[0044] Optionally, the toughening agent includes ethylene propylene diene monomer (EPDM) rubber.

[0045] Optionally, the light stabilizer comprises 2-(2'-hydroxy-3',5'-di-tert-pentylphenyl)benzotriazole.

[0046] Optionally, the nucleating agent includes one of nucleating agent 3988 and nucleating agent NX-8000.

[0047] Optionally, the preparation method of the modified polypropylene material includes: extruding polypropylene resin, compatibilizer, lubricant, antioxidant, toughening agent, light stabilizer, nucleating agent and laser engraving powder in a twin-screw extruder and granulating to obtain the modified polypropylene material.

[0048] The Peak racket provided by this invention has at least one of the following beneficial technical effects compared to the prior art: 1. By using recyclable polypropylene material for both the foamed inner core and the outer shell, Peak rackets can effectively improve their environmental friendliness. At the same time, adding laser engraving powder to the polypropylene shell can effectively improve the laser engraving effect. In addition, by using laser engraving technology to build custom patterns on the surface of the polypropylene shell, there is no need to dye the polypropylene, thereby effectively improving the recycling performance of Peak rackets. 2. By adding nano-alumina and / or modified nano-alumina as laser engraving powder to modified polypropylene materials, the absorption efficiency of laser energy on the surface of the polypropylene shell can be effectively improved, thereby forming a clear, sharp and high-contrast custom pattern on the polypropylene shell. At the same time, nano-alumina and / or modified nano-alumina can be dispersed as fillers in the polypropylene shell, effectively improving the hitting performance of the polypropylene shell against the pickle and its own mechanical strength.

[0049] 3. By using modified polypropylene material for injection molding of the shell, the use of edge banding strips can be reduced and the production process of Peak rackets can be simplified, which helps to reduce costs and makes Peak rackets more reusable. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall structure of a Peak racket provided by the present invention; Figure 2 This invention provides an exploded structural diagram of a Peak racket; Figure 3 This invention provides a structural schematic diagram of a TPE handle glove for a Peak racket; Figure 4 A flowchart illustrating the preparation process of modified nano-alumina provided by this invention.

[0051] Explanation of reference numerals in the attached figures: 1. Foamed inner core; 2. Polypropylene outer shell; 21. First shell; 22. Second shell; 3. Facepiece; 4. Handle; 5. TPE handle glove; 6. Sweat wicking groove; 7. Friction stripes. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0053] See Figure 1 and Figure 2This invention provides a Peak racket, comprising a polypropylene foamed inner core 1 and a polypropylene outer shell 2 covering the surface of the foamed inner core 1. In fact, the foamed polypropylene inner core effectively absorbs the impact of the Peak ball hitting the racket surface, while providing a better hitting feel and reducing the overall weight of the Peak racket. The polypropylene outer shell 2, located on the surface of the foamed inner core 1, not only protects the polypropylene inner core but also gives the racket greater elasticity, which is beneficial for returning the Peak ball.

[0054] In fact, the surface of the polypropylene shell 2 has a custom pattern formed by laser engraving. The custom pattern allows for personalized design of the Peak racket. At the same time, the use of laser engraving for pattern design eliminates the need for spraying, dyeing and other processes on the polypropylene shell 2, which helps to shorten the overall production cycle of the Peak racket and also facilitates the green recycling of the polypropylene shell 2.

[0055] In fact, according to the region, the Peak racket can be divided into a racket face 3 and a handle 4. The racket face 3 is used to contact and return the Peak ball, while the handle 4 is used by the athlete to hold the racket. In some embodiments, the handle 4 can be covered with a TPE grip glove 5. The TPE grip glove 5 helps to effectively improve the athlete's grip comfort and increase friction.

[0056] In some embodiments, the outer surface of the TPE glove 5 is provided with sweat-wicking grooves 6 or sweat-wicking holes, and friction stripes 7 are also provided on the outer side of the TPE glove 5. Specifically, see... Figure 3 Multiple crisscrossing sweat-wicking grooves 6 are formed on the outer surface of the TPE glove 5. These grooves divide the outer surface of the TPE glove 5 into regions, forming a sweat-wicking area composed of the crisscrossing and interconnected sweat-wicking grooves 6 and a friction area between the sweat-wicking areas. Friction stripes 7 are set in the friction area of ​​the TPE glove 5. Multiple friction stripes 7 intersect with each other in the friction area and form friction bumps at the middle of the intersection.

[0057] In some embodiments, the polypropylene shell 2 includes a symmetrically spliced ​​first shell 21 and a second shell 22, and both the first shell 21 and the second shell 22 are formed by injection molding. In fact, to ensure the integrity of the racket face 3, the first shell 21 and the second shell 22 can be spliced ​​together on the side of the Peak racket and fixed by snap-fitting and / or laser welding. This effectively improves the production efficiency of Peak rackets and facilitates industrialized assembly line production.

[0058] In fact, the polypropylene shell is made by injection molding and curing modified polypropylene material. The modified polypropylene material used includes a polypropylene base adhesive and laser engraving powder dispersed within the polypropylene base adhesive. The laser engraving powder includes nano-alumina and / or modified nano-alumina. Specifically, by dispersing the laser engraving powder within the polypropylene base adhesive, the laser absorption efficiency of the polypropylene shell can be improved after curing, as well as the mechanical properties of the polypropylene shell and the feel of hitting the pickleball.

[0059] In some embodiments, the modified nano-alumina includes an alumina core and a mesoporous silica layer coating the surface of the alumina core, wherein neodymium oxide nanoparticles are doped into the mesoporous silica layer. In fact, adding modified nano-alumina to a polypropylene shell not only improves laser absorption efficiency using the doped neodymium oxide nanoparticles, but also confines heat using the mesoporous silica layer, thereby improving the contrast and accuracy of the laser-etched pattern.

[0060] Furthermore, by modifying the surface of nano-alumina with a mesoporous silica layer, it is beneficial to improve the compatibility and dispersibility of modified nano-alumina in polypropylene base adhesive, avoid the sedimentation of modified nano-alumina in the base adhesive, and at the same time, the uniformly dispersed modified nano-alumina can serve as heterogeneous nucleation sites, thereby effectively refining the polypropylene structure. It can also serve as an inorganic filler to effectively improve the structural strength of the polypropylene shell.

[0061] In some embodiments, the method for preparing modified nano-alumina includes: hydrolyzing and condensing nano-alumina with a mesoporous template on its surface in a mixed solution containing tetraethyl orthosilicate and neodymium ions, followed by drying, calcination, and surface silane activation to obtain modified nano-alumina.

[0062] In fact, during the hydrolysis and condensation process, the mesoporous template on the surface of nano-silica adsorbs neodymium ions in the mixed solution and acts as a guiding agent to promote the hydrolysis of tetraethyl orthosilicate and its self-assembly and condensation on the surface of nano-alumina to form silica nanogel, and encapsulates neodymium ions in the gel layer. Drying and calcination can effectively remove the mesoporous template while retaining the mesoporous channels, and can also promote the solidification of the nano-silica framework, so that neodymium oxide nanoparticles are stably doped into the mesoporous channels and framework of silica.

[0063] In some embodiments, see Figure 4 The preparation method of modified nano-alumina includes the following steps: S1. A mixed suspension was prepared by wetting nano-alumina in a mesoporous template solution; S2. After dissolving neodymium salt in a mixed suspension, tetraethyl orthosilicate is added in an alkaline environment for hydrolysis and condensation, followed by separation to obtain the composite material. S3. The composite material is dried, calcined, and surface activated with silane to obtain modified nano-alumina.

[0064] In fact, in step S1, the nano-alumina is immersed in the mesoporous template solution. Through electrostatic adsorption, the mesoporous template agent is attached to the surface of the nano-alumina, which can improve the dispersion stability of the nano-alumina in the mixed suspension and avoid the agglomeration and sedimentation of the nano-alumina in the mixed suspension.

[0065] Specifically, the average particle size of the nano-alumina used is 10nm-50nm. Using nano-sized alumina powder improves compatibility with polypropylene-based adhesives, prevents precipitation that could lead to a decrease in mechanical properties, and enhances responsiveness to laser engraving. Furthermore, nano-sized alumina powder also improves the resolution of patterns generated during laser engraving, resulting in custom patterns with high resolution and clearly visible edges. In some embodiments, the nano-alumina used includes one of α-Al₂O₃ and γ-Al₂O₃, preferably γ-Al₂O₃.

[0066] In some embodiments, the mesoporous template agent used in the mesoporous template solution includes one of tetradecyltrimethylammonium bromide (TTAB), hexadecyltrimethylammonium bromide (CTAB), and octadecyltrimethylammonium bromide (STAB). In fact, the length of the alkyl chain in the mesoporous template agent affects the mesoporous pore size in the mesoporous silica layer; the longer the alkyl chain, the larger the resulting gel micelles, and consequently, the larger the pore size.

[0067] In some embodiments, the mass ratio of nano-alumina to mesoporous template agent used in step S1 is 1:(0.1-0.3). In practice, adjusting the amount of mesoporous template agent helps control the thickness of the gel layer coating the nano-alumina surface. Specifically, the nano-alumina can be immersed in a mesoporous template solution at 50℃-70℃ for 1-3 hours, which facilitates sufficient modification of the nano-alumina surface.

[0068] In some further embodiments, nano-alumina can be added to a mesoporous template solution and then immersed in an ultrasonic environment with a power of 200W-800W. Ultrasonic treatment effectively removes microbubbles adhering to the surface of the nano-alumina and promotes uniform dispersion of the nano-alumina in the mesoporous template solution, thus improving the uniformity of the mesoporous template agent modified on the surface of the nano-alumina. Specifically, during the immersion process, the ultrasonic frequency can be controlled to be 30 seconds of ultrasonic treatment every 1 minute followed by 30 seconds of resting.

[0069] In some embodiments, during step S2, neodymium salt is stirred and dissolved in a mixed suspension at 50°C-70°C. Neodymium ions can be directionally adsorbed by a mesoporous template modified on the surface of nano-alumina, thus allowing neodymium ions to adhere to the surface of nano-alumina. After tetraethyl orthosilicate hydrolyzes to generate nano-silica, neodymium ions can be encapsulated inside the silica gel layer, thereby forming a silica-neodymium ion composite gel structure.

[0070] In some embodiments, the neodymium salt used in step S2 includes one of neodymium nitrate, neodymium acetate, and neodymium chloride. In practice, after dissolving the neodymium salt in the mixed suspension, the mass ratio of neodymium ions to nano-alumina is (0.3-0.5):1, which allows for adjustment of the neodymium ion content in the composite gel structure. In some further embodiments, the neodymium salt can be added to the mixed suspension and then dissolved by ultrasonication. This facilitates the uniform diffusion of neodymium ions in the mixed suspension, thereby improving the dispersion uniformity of neodymium ions in the composite gel structure.

[0071] In some embodiments, during step S2, after adding neodymium salt and stirring to dissolve, ammonia can be added to the mixed suspension to adjust the mixed suspension to an alkaline environment. This alkaline environment promotes the co-hydrolysis and condensation of neodymium salt and tetraethyl orthosilicate, thereby facilitating the formation of uniform silica gel and neodymium hydroxide nanoparticles on the surface of nano-alumina. Specifically, before adding tetraethyl orthosilicate, an ethanol solution of tetraethyl orthosilicate can be prepared by stirring and mixing tetraethyl orthosilicate in anhydrous ethanol, and then added dropwise to the mixed solution.

[0072] In some embodiments, the mixing ratio of tetraethyl orthosilicate to nano-alumina added during step S2 is 0.5 mL / g to 2 mL / g. In fact, by adjusting the amount of tetraethyl orthosilicate added, the thickness of the mesoporous silica layer formed on the surface of the modified nano-alumina can be adjusted, promoting uniform coating of the silica gel layer on the nano-alumina surface without creating an excessively thick mesoporous silica layer that could affect laser engraving performance.

[0073] In some embodiments, during step S2, tetraethyl orthosilicate can be added dropwise in a water bath at 50°C-70°C to carry out the hydrolysis reaction. In practice, to improve the diffusion efficiency of tetraethyl orthosilicate in the mixed suspension, ultrasonic treatment can be performed during the addition of tetraethyl orthosilicate, and the ultrasonic reaction can be continued for 12-24 hours after the addition of tetraethyl orthosilicate, thereby promoting the complete hydrolysis of tetraethyl orthosilicate and neodymium salt to form a stable nano-silica gel layer.

[0074] In some embodiments, after adding tetraethyl orthosilicate for hydrolysis and condensation in step S2, the bottom precipitate can be separated by centrifugation at 400×g-500×g. In fact, high-speed centrifugation can effectively obtain the composite material while simultaneously separating the pure silica nanoparticles doped in the mixed suspension, thereby improving the purity of the composite material. Furthermore, controlling the centrifugal force can prevent damage to the gel layer structure during centrifugation.

[0075] In some further embodiments, after obtaining the bottom precipitate by centrifugation in step S2, the bottom precipitate can be washed with an ethanol-water mixture to facilitate the removal of unreacted substances adhering to the surface of the composite material. Specifically, the obtained composite material has an alumina-based core formed by nano-silica and a nano-silica gel layer wrapped around the surface of the alumina-based core, and the nano-silica gel layer is doped with neodymium ions.

[0076] In some embodiments, during step S3, the composite material can be dried in a vacuum environment at 80°C-100°C. In fact, drying the composite material removes adhering moisture and ethanol solvent, prevents the collapse of the gel on the composite surface, promotes the pre-combining of neodymium ions with silica, helps maintain the dispersion of neodymium ions in the mesoporous silica, and, through the vacuum effect during drying, allows internal moisture and ethanol to fully seep out through the mesoporous channels while maintaining the integrity of the channels.

[0077] In some embodiments, during step S3, the dried composite material can be calcined in an oxygen-containing atmosphere at 500°C-600°C for 3-6 hours. In fact, high-temperature oxidation calcination can transform the nano-silica gel into a mesoporous silica layer, while simultaneously converting neodymium ions into neodymium oxide nanoparticles and sintering them into the framework and mesoporous channels of the mesoporous silica. Specifically, the oxygen-containing atmosphere used includes 10%-30% oxygen by volume and the balance being a protective gas; furthermore, the oxygen-containing atmosphere can be clean air.

[0078] In some embodiments, after the dried composite material is calcined at high temperature in step S3, a silane coupling agent can be used to activate its surface silanes, thereby effectively increasing the number of active groups on the surface and thus improving the dispersibility of modified nano-alumina in polypropylene adhesive. In practice, the silane coupling agent used may include one of KH-550, KH-560, and KH570, and the mass ratio of the silane coupling agent to the dried and calcined composite material is (0.1-0.2):1.

[0079] In fact, the modified polypropylene material by weight includes: 70-80 parts polypropylene resin, 3-6 parts compatibilizer, 0.1-0.5 parts lubricant, 0.3-0.6 parts antioxidant, 3-5 parts toughening agent, 0.1-0.3 parts light stabilizer, 0.1-0.3 parts nucleating agent, and 1-2 parts laser engraving powder.

[0080] In some embodiments, the polypropylene resin used has a melt index of 40 g / 10 min to 50 g / 10 min, and the polypropylene resin includes one of copolymer polypropylene and homopolymer polypropylene. The compatibilizer includes maleic anhydride-grafted polypropylene. The lubricant includes one of calcium stearate and polyethylene wax. The antioxidant includes one of antioxidant 1010 and antioxidant 168. The toughening agent includes EPDM rubber. The light stabilizer includes 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole (light stabilizer 328). The nucleating agent includes one of nucleating agent 3988 and nucleating agent NX-8000.

[0081] In some embodiments, the method for preparing the modified polypropylene material includes: extruding polypropylene resin, compatibilizer, lubricant, antioxidant, toughening agent, light stabilizer, nucleating agent and laser engraving powder in a twin-screw extruder and granulating to obtain the modified polypropylene material.

[0082] Preparation Example 1 Example 1 provides a method for preparing modified nano-alumina, comprising the following steps: S1. A mesoporous template solution with a concentration of 2 mg / mL was prepared by dissolving hexadecyltrimethylammonium bromide (CTAB, CAS: 57-09-0) in deionized water. Then, nano-alumina (γ-Al2O3, purchased from Zhejiang Zhitai Micro New Materials Co., Ltd., model Vk-L20Y, particle size 10nm-20nm, specific surface area 120m²) was added. 2 / g, γ-Al2O3 and CTAB in a mass ratio of 1:0.2) were added to the mesoporous template solution and ultrasonically dispersed at 500W for 2h in a 60℃ water bath to obtain a mixed suspension. S2, add neodymium nitrate hexahydrate (Nd(NO3)3·6H2O, Nd 3+A composite suspension was prepared by adding a mixture of γ-Al2O3 (at a mass ratio of 0.4:1) to a mixed suspension at a constant temperature of 60℃ and sonicating it for 5 minutes at an ultrasonic power of 500W until completely dissolved. Ammonia was added to the composite suspension to adjust the alkaline environment (pH=10-12), and then a 2% ethanol solution of tetraethyl orthosilicate (the mixing ratio of tetraethyl orthosilicate to γ-Al2O3 was 1mL / g) was added dropwise. The mixture was then reacted in a water bath at 60℃ with an ultrasonic power of 500W for 14 hours. The resulting suspension was transferred to a centrifuge tube, and the bottom precipitate was separated by centrifugation at 400×g. The mixture was then washed three times with a 50% ethanol aqueous solution to obtain the composite material. S3. After drying the composite material in a vacuum drying oven at 80°C for 2 hours, it was transferred to the furnace chamber of an atmosphere furnace and clean air was introduced. The atmosphere furnace was heated to 500°C at a rate of 5°C / min and then held at that temperature for 4 hours. After cooling to room temperature in the furnace, the calcined product was added to a KH-550 solution (the mass ratio of KH550 to the calcined product was 0.1:1) at a solid-liquid ratio of 0.05 g / mL and ultrasonically treated for 15 minutes. After separation by filtration, the modified nano-alumina was obtained by drying in a vacuum drying oven at 80°C to constant weight.

[0083] Preparation Example 2 Preparation Example 2 provides a method for preparing modified nano-alumina. The difference from Preparation Example 1 is that CTAB is not added in step S1; instead, nano-alumina (γ-Al2O3, purchased from Zhejiang Zhitai Micro New Materials Co., Ltd., model Vk-L20Y, particle size 10nm-20nm, specific surface area 120m²) is directly added. 2 A mixed suspension was prepared by ultrasonic dispersion of γ-Al2O3 and CTAB in deionized water at a mass ratio of 1:0.2.

[0084] Preparation Example 3 Preparation Example 3 provides a method for preparing modified nano-alumina. The difference from Preparation Example 1 is that step S2 involves: mixing neodymium nitrate hexahydrate (Nd(NO3)3·6H2O, Nd...)... 3+ The γ-Al2O3 (mass ratio of 0.4:1) was added to a mixed suspension at a constant temperature of 60℃. After sonication at 500W for 5 minutes until completely dissolved, a composite suspension was obtained. Ammonia was added to adjust the alkaline environment (pH=10-12), and the mixture was reacted at 500W for 14 hours in a 60℃ water bath. The resulting suspension was transferred to a centrifuge tube, and the bottom precipitate was separated by centrifugation at 400×g. The mixture was then washed three times with a 50% ethanol aqueous solution to obtain the composite material.

[0085] Preparation Example 4 Preparation Example 4 provides a method for preparing modified nano-alumina. The difference from Preparation Example 1 is that step S2 is as follows: after adding ammonia to the mixed suspension to adjust the alkaline environment (pH=10-12), a 2% ethanol solution of tetraethyl orthosilicate (the mixing ratio of tetraethyl orthosilicate and γ-Al2O3 is 1 mL / g) is added dropwise. The mixture is then reacted in a 60°C water bath with 500W ultrasonic power for 14 h. The resulting suspension is transferred to a centrifuge tube, and the bottom precipitate is separated by centrifugation at 400×g. The mixture is then washed three times with a 50% ethanol aqueous solution to obtain the composite material.

[0086] Preparation Example 5 Preparation Example 5 provides a method for preparing modified nano-alumina. The difference from Preparation Example 1 is that the modified nano-alumina is obtained after calcination in step S3.

[0087] Examples 1 to 5 Examples 1 to 5 each provide a modified polypropylene material, and the components and their mass fractions used are shown in Table 1 below.

[0088] Table 1. Components and mass fractions of the modified polypropylene materials in Examples 1 to 5

[0089] In Examples 1 to 5, the polypropylene resin used was M800E purchased from Sinopec Shanghai Petrochemical Co., Ltd., the compatibilizer used was maleic anhydride-grafted polypropylene purchased from Dongguan Dinghai Plastics & Chemical Co., Ltd., the lubricant used was calcium stearate, the antioxidant used was antioxidant 1010, the toughening agent used was EPDM rubber with grade 4725P purchased from Dow Chemical, the light stabilizer used was light stabilizer 328, and the nucleating agent used was nucleating agent 3988.

[0090] The laser engraving powder used in Examples 1 to 3 was nano-alumina (γ-Al2O3), purchased from Zhejiang Zhitai Micro New Materials Co., Ltd., model Vk-L20Y, with a particle size of 10nm-20nm and a specific surface area of ​​120m². 2 / g), the laser engraving powder used in Example 4 is the modified nano alumina obtained in Preparation Example 1, and the laser engraving powder used in Example 5 is a mixture of nano alumina (γ-Al2O3) and modified nano alumina (Preparation Example 1) in a mass ratio of 1:5.

[0091] Examples 6 to 9 Examples 6 to 9 each provide a modified polypropylene material, which differs from Example 4 in that the laser engraving powder used is different, as shown in Table 2 below.

[0092] Table 2. Laser-engraved powders of modified polypropylene materials in Examples 6 to 9

[0093] The preparation methods of the modified polypropylene materials in Examples 1 to 9 all include: adding compatibilizer, lubricant, antioxidant, light stabilizer, nucleating agent, toughening agent and polypropylene resin into a twin-screw extruder, performing melt blending at 180℃-210℃ and screw speed of 350rpm, and adding laser engraving powder into the molten material using a side feeder, followed by blending, extrusion, cooling and granulation to obtain the modified polypropylene material.

[0094] Comparative Example 1 Comparative Example 1 provides a method for preparing a modified polypropylene material, which differs from Example 4 in that no laser engraving powder is added.

[0095] Performance testing The modified polypropylene materials prepared in Examples 1 to 9 and Comparative Example 1 were made into test plates by injection molding. The maximum dynamic friction coefficient of the plates was tested according to the method described in ASTM D1894-14. The results are shown in Table 3 below. After laser marking was performed at 50% power, 600 mm / s speed and 18 kHz frequency, the laser marking effect was observed as shown in Table 3 below.

[0096]

[0097] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A Peak racket, characterized in that, The device includes a polypropylene foamed inner core and a polypropylene outer shell covering the foamed inner core. The foamed inner core and / or the polypropylene outer shell form a handle portion. The handle portion is fitted with a TPE handle glove, and the surface of the polypropylene outer shell has a custom pattern formed by laser engraving. The polypropylene outer shell is made of modified polypropylene material through injection molding and curing. The modified polypropylene material includes polypropylene resin and laser engraving powder dispersed in a polypropylene substrate. The laser engraving powder is modified nano-alumina. The method for preparing the modified nano-alumina includes: hydrolyzing and condensing nano-alumina with a mesoporous template on the surface in a mixed solution containing tetraethyl orthosilicate and neodymium ions, drying, calcining and surface silane activation to obtain modified nano-alumina.

2. The Peak racket according to claim 1, characterized in that, The outer shell also has a racket face that contacts and strikes the pick; the polypropylene outer shell includes a first shell and a second shell that are symmetrically spliced ​​together, and the first shell and the second shell are both formed by injection molding, and the first shell and the second shell are fixed by snap-fitting and / or laser welding; the outer surface of the TPE handle glove is provided with sweat-wicking grooves or sweat-wicking holes, and the outer side of the handle glove is also provided with friction stripes.

3. The Peak racket according to claim 1, characterized in that, The modified nano-alumina includes an alumina core and a mesoporous silica layer covering the surface of the alumina core, and the mesoporous silica layer is doped with neodymium oxide nanoparticles.

4. The Peak racket according to claim 3, characterized in that, The method for preparing the modified nano-alumina includes the following steps: wetting nano-alumina in a mesoporous template solution to obtain a mixed suspension; dissolving neodymium salt in the mixed suspension by stirring, adding tetraethyl orthosilicate in an alkaline environment for hydrolysis and condensation, and then separating the composite material; drying, calcining, and surface silane activation of the composite material to obtain modified nano-alumina.

5. The Peak racket according to claim 4, characterized in that, The mesoporous template solution contains one of tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, and octadecyltrimethylammonium bromide as the mesoporous template agent; the average particle size of the nano-alumina is 10nm-50nm; the nano-alumina contains one of α-Al2O3 and γ-Al2O3; the mass ratio of the nano-alumina to the mesoporous template solution as the mesoporous template agent is 1:(0.1-0.3); it is impregnated under ultrasonic power of 200W-800W; impregnated at 50℃-70℃; impregnated for 1h-3h.

6. The Peak racket according to claim 4, characterized in that, The neodymium salt includes one of neodymium nitrate, neodymium acetate, and neodymium chloride; after the neodymium salt is dissolved in the mixed suspension, the mass ratio of neodymium ions to the nano-alumina is (0.3-0.5):1; the neodymium salt is added to the mixed suspension and then dissolved by ultrasonication; ammonia is added to adjust the mixed suspension to an alkaline environment; an ethanol solution of tetraethyl orthosilicate is added dropwise in the alkaline environment; the neodymium salt is stirred and dissolved in the mixed suspension at 50℃-70℃; the mixing ratio of tetraethyl orthosilicate to the nano-alumina is 0.5mL / g-2mL / g.

7. The Peak racket according to claim 4, characterized in that, Ethyl orthosilicate is added at 50℃-70℃ for hydrolysis; after adding ethyl orthosilicate, the mixture is ultrasonically reacted for 12h-24h; after hydrolysis and condensation, the bottom precipitate is separated by centrifugation at 400×g-500×g; after separation, the mixture is washed with a mixture of ethanol and water; the composite material has an alumina-based core formed by nano-alumina and a nano-silica gel layer wrapped on the surface of the alumina-based core, and the nano-silica gel layer is doped with neodymium ions.

8. The Peak racket according to claim 4, characterized in that, Drying at 80℃-100℃; drying under vacuum; calcining in an oxygen-containing atmosphere; calcining at 500℃-600℃ for 3-6 hours; surface silane activation using a silane coupling agent, wherein the silane coupling agent includes one of KH-550, KH-560, and KH570, and the mass ratio of the silane coupling agent to the dried and calcined composite material is (0.1-0.2):

1.

9. The Peak racket according to claim 1, characterized in that, The modified polypropylene material, by weight, comprises: 70-80 parts polypropylene resin, 3-6 parts compatibilizer, 0.1-0.5 parts lubricant, 0.3-0.6 parts antioxidant, 3-5 parts toughening agent, 0.1-0.3 parts light stabilizer, 0.1-0.3 parts nucleating agent, and 1-2 parts laser engraving powder.

10. The Peak racket according to claim 9, characterized in that, The melt flow index of the polypropylene resin is 40 g / 10 min to 50 g / 10 min; the polypropylene resin includes one of copolymer polypropylene and homopolymer polypropylene; the compatibilizer includes maleic anhydride-grafted polypropylene; the lubricant includes one of calcium stearate and polyethylene wax; the antioxidant includes one of antioxidant 1010 and antioxidant 168; the toughening agent includes ethylene propylene diene monomer (EPDM) rubber; the light stabilizer includes 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole; and the nucleating agent includes one of nucleating agent 3988 and nucleating agent NX-8000. The method for preparing the modified polypropylene material includes: extruding polypropylene resin, compatibilizer, lubricant, antioxidant, toughening agent, light stabilizer, nucleating agent and laser engraving powder in a twin-screw extruder and granulating to obtain the modified polypropylene material.

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