A high-elasticity Pickleball racket

Abstract

The present invention provides a high-elasticity Pickleball racket, which comprises a racket body, a side strip and a handle; a racket core is arranged inside the racket body, grooves are arranged on the racket core, and the grooves are arranged in a horizontal, vertical or oblique direction; elastic materials are filled in the grooves. The Pickleball racket of the present invention has a high elasticity of the racket core, good resilience, excellent mechanical properties and a long service life. In the present invention, by compounding polyester resin, epoxy resin and ABS resin, the elasticity of the elastic material is improved. Moreover, in the present invention, by adding a plasticizer, the elastic material is not easily broken after molding, especially after undergoing the processes of foaming expansion and cooling contraction, and can still maintain good elasticity.

Description

Technical Field

[0001] The present invention belongs to the technical field of Pickleball rackets, and particularly relates to a Pickleball racket with high elasticity. Background Art

[0002] Pickleball is a sport that combines elements of tennis, badminton, and table tennis, and has rapidly gained popularity worldwide in recent years. As the core equipment of this sport, the design and characteristics of Pickleball rackets are crucial for improving players' performance. The basic structure of a Pickleball racket: The racket face: The racket face of a Pickleball racket is usually smaller than that of a tennis racket but larger than that of a badminton racket, which helps to precisely control the direction and speed of the ball. The racket face is mostly made of composite materials such as carbon fiber, nylon, or fiberglass to provide good power transmission and ball control ability. The frame: The frame material of the racket is also mostly made of lightweight and strong composite materials such as carbon fiber composites, aiming to maintain the strength of the racket while reducing the weight, making it easy to swing the racket for a long time without fatigue. The handle: The handle design focuses on the comfort of holding. Usually, it is wrapped with a sweat-absorbing tape or provides replaceable grip leather to adapt to the feel requirements of different players. The handle size is diverse, and players should choose the size suitable for their hand shape to ensure the best controllability. The racket core:

[0003] In the prior art, the racket core of a Pickleball racket is integrally formed, and the material is mainly a polypropylene honeycomb core, aiming to improve the durability of the racket and reduce costs, and is suitable for players of various levels. However, the existing racket core has poor elasticity and anti-twisting ability. The racket core cannot effectively store and release energy at the moment of hitting the ball. Even if the player swings the racket with great force, it is difficult to hit a powerful return ball, which makes the player have to sacrifice control in order to hit the ball far or make a powerful attack. And the service life is relatively low. Summary of the Invention

[0004] The purpose of the present invention is to provide a Pickleball racket with high elasticity.

[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A Pickleball racket with high elasticity, the Pickleball racket includes a racket body, side strips, and a handle; a racket core is provided inside the racket body, grooves are provided on the racket core, and the direction of the grooves is horizontal, vertical, or diagonal; elastic materials are filled in the grooves;

[0007] The preparation method of the elastic material includes the following steps:

[0008] (1) Preparation of plasticizer: Mix 27 - 34 parts by mass of propene - 1,2,3 - tricarboxylic acid, 48 - 55 parts by mass of 2 - ethylhexanol, 48 - 57 parts by mass of toluene, and 2.5 - 3.2 parts by mass of p - toluenesulfonic acid. Under the condition of a stirring speed of 400 - 500 rpm, carry out an esterification reaction at an esterification temperature of 120 - 130 °C for a reaction time of 5 - 7 h to obtain a mixed solution; add an equal - volume aqueous alkali solution to the mixed solution and react at a reaction temperature of 47 - 53 °C for a reaction time of 20 - 30 min; then carry out extraction to obtain the upper organic phase; after distilling, purifying, decolorizing, and filtering the upper organic phase, obtain the plasticizer;

[0009] The structure of the plasticizer is as follows:

[0010]

[0011] (2) Weigh the components of the foaming material according to the following parts by mass: 43 - 50 parts of polyester resin, 28 - 33 parts of epoxy resin, 20 - 25 parts of ABS resin, 6 - 10 parts of modified filler, 3 - 5 parts of plasticizer, 0.5 - 1.4 parts of lubricant, 1 - 1.5 parts of activator, 0.8 - 1.4 parts of cross - linker, 2 - 3 parts of foaming agent, and 2 - 4 parts of pigment;

[0012] (3) Preparation of foaming material: Mix polyester resin, epoxy resin, ABS resin, modified filler, lubricant, plasticizer, activator, and pigment. When the temperature is raised to 113 - 118 °C, carry out kneading for 10 - 15 min; then add the cross - linker and foaming agent, continue to raise the temperature to 120 - 125 °C, and carry out kneading for 4 - 7 min to obtain a mixed material; granulate the mixed material, inject it into a mold, the mold temperature is 185 - 190 °C, after vulcanization, form it, and carry out constant - temperature shaping to obtain the foaming material;

[0013] (4) Use carbon fiber to wrap the foaming material to obtain an elastic material.

[0014] Furthermore, the polyester resin is a saturated polyester resin with a number - average molecular weight of 6×10 3 Da, a glass transition temperature of 46 °C, an acid value of 5 KOHmg / g, and a hydroxyl value of 619 KOHmg / g. It is purchased from Dongguan Haosheng Plastic Raw Material Co., Ltd., and the model is TOYOBOGK810.

[0015] Furthermore, the epoxy resin is a glycidyl ether - type epoxy resin with an epoxy equivalent of 180 - 190 g / eq and a viscosity of 11000 - 15000 cps at 25 °C. It is purchased from Wanqing Chemical Technology Co., Ltd., and the model is NPEL - 128.

[0016] Furthermore, the molecular weight of the ABS resin is 120,000 Da, the mass fraction of butadiene in the ABS resin is 45%, the mass fraction of acrylonitrile is 25%, and the mass fraction of styrene is 30%; the melt index of the ABS resin at 220 °C and 10 kg is 43 g / 10 min. It is purchased from Daken Energy Resin Co., Ltd. of Japan.

[0017] The molecular chain of the polyester resin is relatively rigid and has good hardness. However, when used as the elastic material of a pick racket, its own elasticity is poor, the network structure inside the material is not tight enough, and it is difficult to provide sufficient resilience. In the present invention, by compounding the polyester resin with an epoxy resin and an ABS resin, the elasticity of the elastic material is improved. Moreover, in the present invention, by adding a plasticizer, the elastic material is not easily broken after molding, especially after the processes of foaming expansion and cooling contraction, and can still maintain good elasticity. The analysis is that the plasticizer of the present invention can weaken the intermolecular force of the polymer, making it easier for the foaming agent gas to diffuse in the polymer to form bubbles, which helps to generate a finer and more uniform cell structure, thereby improving the cell quality and overall performance of the foamed material.

[0018] Furthermore, the preparation method of the modified filler is as follows:

[0019] (1) Mix alumina, silicon carbide, and boron nitride with a mass ratio of 1:1.4 - 1.8:0.3 - 0.9 to obtain a mixed powder;

[0020] (2) Mix 15 parts by mass of the mixed powder, 140 - 150 parts by mass of water, 0.4 - 0.8 parts by mass of 3 - amino - 1,2,4 - triazole - 5 - thiol, and 0.6 - 0.8 parts by mass of a 70 - 75 wt% aqueous methanesulfonic acid solution to obtain a mixed solution A. Mix 0.24 - 0.27 parts by mass of sodium nitrite and 15 - 18 parts by mass of water to obtain a mixed solution B; mix the mixed solution A and the mixed solution B, and stir at 70 - 75 °C for 60 - 80 min; cool to room temperature, and adjust the pH to 8 - 8.5 with a 0.1 - 0.3 mol / L aqueous NaOH solution, filter to collect the solid, wash and dry to obtain the modified filler.

[0021] 3 - amino - 1,2,4 - triazole - 5 - thiol, CAS: 16691 - 43 - 3.

[0022] Furthermore, the particle size of alumina is 30 - 60 nm, and the specific surface area is 10 - 20 m 2 / g; the particle size of silicon carbide is 500 - 800 nm, and the average specific surface area is 20 m 2 / g; the particle size of boron nitride is 2 - 20 μm, and the specific surface area is 6 - 25 m 2 / g.

[0023] Further, the lubricant is low-density polyethylene wax, which has a viscosity of 450 cps at 140 °C and a density of 0.93 g / cm 3 , a particle size of 1410 μm, and is purchased from Honeywell, USA, with the model number A-C 9A.

[0024] The present invention attempts to improve the tear strength of the elastic material by adding fillers. However, the inventors found that adding fillers would affect the elasticity of the elastic material, which was analyzed to be caused by poor dispersion of the material in the system. The present invention modifies the fillers to improve the tear strength of the elastic material without reducing the elasticity of the elastic material. The analysis is that a triazole group is introduced onto the modified fillers of the present invention, which has better compatibility with other components. Such modified fillers can not only maintain their enhancing effect on the tear strength, but also effectively reduce the interfacial tension between the fillers and the resin, improve the interaction between the two, so that the fillers are more evenly dispersed in the foaming system, reducing the impact on the elasticity of the material. At the same time, under such conditions, the elongation at break of the elastic material is also improved.

[0025] Further, the activator is zinc oxide.

[0026] Further, the crosslinking agent is dicumyl peroxide.

[0027] Further, the blowing agent is azodicarbonamide.

[0028] Further, the purity of the p-toluenesulfonic acid is 99%.

[0029] Further, the alkaline aqueous solution is a sodium carbonate aqueous solution, and the mass fraction of the solute in the alkaline aqueous solution is 4-7%.

[0030] Further, the extraction is repeated three times with ethyl acetate and washed with clear water.

[0031] Further, the conditions for distillation and purification are: the temperature is 88-94 °C; the vacuum degree is 45-55 mbar.

[0032] Further, the pigment is a masterbatch.

[0033] Further, the decolorization conditions are: the decolorization is specifically carried out with activated carbon, and the addition amount of the activated carbon is 5-10 parts by mass; the decolorization temperature is 40-45 °C, and the decolorization time is 60-80 min.

[0034] Further, the vulcanization time is 340-370 s; the constant temperature setting conditions include: successively at 85 °C, 75 °C, 60 °C, and 50 °C, and each temperature is maintained for 5-6 min.

[0035] Further, the density of the carbon fiber is 1.5-1.8 g / cm 3 .

[0036] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0037] 1. The present invention provides a high-elasticity Pickleball racket with a high-elastic core, good resilience, excellent mechanical properties, and a long service life.

[0038] 2. By compounding polyester resin, epoxy resin, and ABS resin, the present invention improves the elasticity of the elastic material. Moreover, by adding a plasticizer, the elastic material is not easily broken after molding, especially after the processes of foaming expansion and cooling contraction, and still can maintain good elasticity.

[0039] 3. By modifying the filler, the present invention improves the tear strength of the elastic material without reducing its elasticity. At the same time, under this condition, the elongation at break of the elastic material is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural view of the groove of the core of Example 1;

[0041] Figure 2 is a schematic structural view of the elastic material filled in the groove of the core of Example 1;

[0042] Figure 3 is a schematic cross-sectional view of the elastic material filled in the groove of the core of Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work shall fall within the protection scope of the present invention.

[0044] Example 1

[0045] Please refer to Figures 1 to 3 , this embodiment provides a high-elasticity Pickleball racket, the Pickleball racket includes a racket body, a side strip, and a handle; a racket core is provided inside the racket body, grooves are provided on the racket core, and the grooves are arranged horizontally, vertically, or obliquely; elastic materials are filled in the grooves;

[0046] The preparation method of the elastic material includes the following steps:

[0047] (1) Preparation of plasticizer: Mix 30 parts by mass of propylene-1,2,3-tricarboxylic acid, 52 parts by mass of 2-ethylhexanol, 53 parts by mass of toluene, and 2.9 parts by mass of p-toluenesulfonic acid. Under the condition of a stirring speed of 450 rpm, carry out an esterification reaction at an esterification temperature of 125 °C for 6 h to obtain a mixed solution; add an equal volume of alkaline aqueous solution to the mixed solution and react at a reaction temperature of 50 °C for 25 min; then carry out extraction to obtain the upper organic phase; distill and purify, decolorize and filter the upper organic phase to obtain the plasticizer;

[0048] The structure of the plasticizer is as follows:

[0049]

[0050] (2) Weigh the components of the foaming material according to the following parts by mass: 48 parts of polyester resin, 31 parts of epoxy resin, 22 parts of ABS resin, 9 parts of modified filler, 4 parts of plasticizer, 1 part of lubricant, 1.2 parts of activator, 1.1 parts of crosslinking agent, 2.5 parts of foaming agent, and 3 parts of pigment;

[0051] (3) Preparation of foaming material: Mix polyester resin, epoxy resin, ABS resin, modified filler, lubricant, plasticizer, activator, and pigment. When the temperature is raised to 115 °C, carry out kneading for 12 min; then add the crosslinking agent and foaming agent, and continue to raise the temperature to 122 °C and carry out kneading for 5 min to obtain a mixed material; granulate the mixed material and inject it into a mold. The mold temperature is 188 °C, and after vulcanization and molding, carry out constant temperature setting to obtain the foaming material;

[0052] (4) Wrap the foaming material with carbon fiber to obtain an elastic material.

[0053] The polyester resin is a saturated polyester resin with a number-average molecular weight of 6×10 3 Da, a glass transition temperature of 46 °C, an acid value of 5 KOHmg / g, and a hydroxyl value of 619 KOHmg / g. It is purchased from Dongguan Haosheng Plastic Raw Materials Co., Ltd., and the model is TOYOBOGK810.

[0054] The epoxy resin is a glycidyl ether type epoxy resin with an epoxy equivalent of 180 - 190 g / eq and a viscosity of 11000 - 15000 cps at 25 °C. It is purchased from Wanqing Chemical Technology Co., Ltd., and the model is NPEL-128.

[0055] The molecular weight of the ABS resin is 120,000 Da. The mass fraction of butadiene in the ABS resin is 45%, the mass fraction of acrylonitrile is 25%, and the mass fraction of styrene is 30%; the melt index of the ABS resin at 220 °C and 10 kg is 43 g / 10 min. It is purchased from Dakeneng Resin Co., Ltd., Japan.

[0056] The preparation method of the modified filler is as follows:

[0057] (1) Mix alumina, silicon carbide and boron nitride with a mass ratio of 1:1.6:0.7 to obtain a mixed powder; the particle size of alumina is 30-60 nm, and the specific surface area is 10-20 m 2 / g; the particle size of silicon carbide is 500-800 nm, and the average specific surface area is 20 m 2 / g; the particle size of boron nitride is 2-20 μm, and the specific surface area is 6-25 m 2 / g. Alumina is purchased from Zhejiang Zhitaina Micro New Materials Co., Ltd.; silicon carbide is purchased from Jinlei Technology; boron nitride is purchased from Shandong Jingyi New Materials Co., Ltd.

[0058] (2) Mix 15 parts by mass of the mixed powder, 145 parts by mass of water, 0.6 part by mass of 3-amino-1,2,4-triazole-5-thiol and 0.7 part by mass of 72 wt% methanesulfonic acid aqueous solution to obtain a mixed solution A. Mix 0.25 part by mass of sodium nitrite and 16 parts by mass of water to obtain a mixed solution B; mix the mixed solution A and the mixed solution B, and stir at 72 °C for 70 min; cool to room temperature, and adjust the pH to 8.2 with 0.2 mol / L NaOH aqueous solution, filter to collect the solid, wash and dry to obtain the modified filler.

[0059] 3-amino-1,2,4-triazole-5-thiol, CAS: 16691-43-3.

[0060] The lubricant is low-density polyethylene wax, and the viscosity of the low-density polyethylene wax at 140 °C is 450 cps, and the density is 0.93 g / cm 3 , the particle size is 1410 μm, purchased from Honeywell Company of the United States, and the model is A-C 9A.

[0061] The active agent is zinc oxide.

[0062] The cross-linking agent is dicumyl peroxide.

[0063] The foaming agent is azodicarbonamide.

[0064] The purity of the p-toluenesulfonic acid is 99%.

[0065] The alkaline aqueous solution is a sodium carbonate aqueous solution, and the mass fraction of the solute in the alkaline aqueous solution is 6%.

[0066] The extraction is carried out by repeating extraction three times with ethyl acetate and washing with clear water.

[0067] The conditions for distillation and purification are: the temperature is 90 °C; the vacuum degree is 50 mbar.

[0068] The pigment is masterbatch.

[0069] The decolorization conditions are as follows: The decolorization is specifically carried out using activated carbon, and the addition amount of the activated carbon is 8 parts by mass; the decolorization temperature is 42 °C, and the decolorization time is 70 min.

[0070] The vulcanization time is 350 s; the constant temperature shaping conditions include: successively at temperatures of 85 °C, 75 °C, 60 °C, and 50 °C, and each temperature is maintained for 6 min.

[0071] The density of the carbon fiber is 1.6 g / cm 3 。

[0072] Example 2

[0073] This example provides a high-elasticity Pickleball racket, which includes a racket body, a side strip, and a handle; a racket core is provided inside the racket body, and grooves are provided on the racket core, and the direction of the grooves is horizontal, vertical, or oblique; elastic materials are filled in the grooves;

[0074] The preparation method of the elastic material includes the following steps:

[0075] (1) Prepare a plasticizer: Mix 27 parts by mass of propylene-1,2,3-tricarboxylic acid, 55 parts by mass of 2-ethylhexanol, 48 parts by mass of toluene, and 3.2 parts by mass of p-toluenesulfonic acid, and carry out an esterification reaction under the condition of a stirring speed of 400 rpm, the esterification temperature is 130 °C, and the reaction time is 5 h to obtain a mixed solution; add an equal volume of an aqueous alkali solution to the mixed solution and carry out a reaction, the reaction temperature is 53 °C, and the reaction time is 20 min; then carry out extraction to obtain the upper organic phase; distill and purify, decolorize and filter the upper organic phase to obtain a plasticizer;

[0076] The structure of the plasticizer is as follows:

[0077]

[0078] (2) Weigh the components of the foaming material according to the following parts by mass: 50 parts of polyester resin, 28 parts of epoxy resin, 25 parts of ABS resin, 6 parts of modified filler, 5 parts of plasticizer, 0.5 part of lubricant, 1.5 parts of activator, 0.8 part of crosslinking agent, 3 parts of foaming agent, and 2 parts of pigment;

[0079] (3) Prepare the foaming material: Mix the polyester resin, epoxy resin, ABS resin, modified filler, lubricant, plasticizer, activator, and pigment, and when the temperature is raised to 118 °C, carry out kneading for 10 min; then add the crosslinking agent and the foaming agent, and continue to raise the temperature to 125 °C, and carry out kneading for 4 min to obtain a mixed material; granulate the mixed material, inject it into a mold, the mold temperature is 190 °C, form after vulcanization, and carry out constant temperature shaping to obtain the foaming material;

[0080] (4) Wrap the foaming material with carbon fiber to obtain an elastic material.

[0081] The polyester resin is a saturated polyester resin with a number-average molecular weight of 6×10 3 Da, a glass transition temperature of 46 °C, an acid value of 5 KOHmg / g, and a hydroxyl value of 619 KOHmg / g. It is purchased from Dongguan Haosheng Plastic Raw Materials Co., Ltd., and the model is TOYOBO GK810.

[0082] The epoxy resin is a glycidyl ether type epoxy resin with an epoxy equivalent of 180 - 190 g / eq and a viscosity of 11000 - 15000 cps at 25 °C. It is purchased from Wanqing Chemical Technology Co., Ltd., and the model is NPEL-128.

[0083] The ABS resin has a molecular weight of 120,000 Da. The mass fraction of butadiene in the ABS resin is 45%, the mass fraction of acrylonitrile is 25%, and the mass fraction of styrene is 30%. The melt index of the ABS resin at 220 °C and 10 kg is 43 g / 10 min. It is purchased from Daken Energy Resin Co., Ltd., Japan.

[0084] The preparation method of the modified filler is as follows:

[0085] (1) Mix alumina, silicon carbide, and boron nitride with a mass ratio of 1:1.4:0.9 to obtain a mixed powder; the particle size of alumina is 30 - 60 nm, and the specific surface area is 10 - 20 m 2 / g; the particle size of silicon carbide is 500 - 800 nm, and the average specific surface area is 20 m 2 / g; the particle size of boron nitride is 2 - 20 μm, and the specific surface area is 6 - 25 m 2 / g. Alumina is purchased from Zhejiang Zhitaina Micro New Materials Co., Ltd.; silicon carbide is purchased from Jinlei Technology; boron nitride is purchased from Shandong Jingyi New Materials Co., Ltd.

[0086] (2) Mix 15 parts by mass of the mixed powder, 140 parts by mass of water, 0.8 parts by mass of 3-amino-1,2,4-triazole-5-thiol, and 0.6 parts by mass of a 70 - 75 wt% methanesulfonic acid aqueous solution to obtain a mixed solution A. Mix 0.27 parts by mass of sodium nitrite and 15 parts by mass of water to obtain a mixed solution B. Mix the mixed solution A and the mixed solution B, and stir at 75 °C for 60 min; cool to room temperature, and adjust the pH to 8 with a 0.3 mol / L NaOH aqueous solution, filter and collect the solid, wash and dry to obtain the modified filler.

[0087] 3-amino-1,2,4-triazole-5-thiol, CAS: 16691-43-3.

[0088] The lubricant is low-density polyethylene wax, the viscosity of the low-density polyethylene wax at 140 °C is 450 cps, the density is 0.93 g / cm 3 , the particle size is 1410 μm, purchased from Honeywell Company in the United States, and the model is A-C 9A.

[0089] The active agent is zinc oxide.

[0090] The cross-linking agent is dicumyl peroxide.

[0091] The foaming agent is azodicarbonamide.

[0092] The purity of the p-toluenesulfonic acid is 99%.

[0093] The alkaline aqueous solution is a sodium carbonate aqueous solution, and the mass fraction of the solute in the alkaline aqueous solution is 7%.

[0094] The extraction is repeated three times with ethyl acetate and washed with clear water.

[0095] The conditions for distillation and purification are: the temperature is 88 °C; the vacuum degree is 55 mbar.

[0096] The pigment is a masterbatch.

[0097] The decolorization conditions are: the decolorization is specifically carried out with activated carbon, the addition amount of the activated carbon is 5 parts by mass; the decolorization temperature is 45 °C, and the decolorization time is 60 min.

[0098] The vulcanization time is 370 s; the constant temperature shaping conditions include: successively at 85 °C, 75 °C, 60 °C, and 50 °C, and each temperature is maintained for 5-6 min.

[0099] The density of the carbon fiber is 1.5 g / cm 3 .

[0100] Comparative Example 1

[0101] The difference between this comparative example and Example 1 is: the components of the foaming material are weighed according to the following mass parts: 40 parts of polyester resin, 22 parts of epoxy resin, 39 parts of ABS resin, 6 parts of modified filler, 5 parts of plasticizer, 0.5 part of lubricant, 1.5 parts of active agent, 0.8 part of cross-linking agent, 3 parts of foaming agent, and 2 parts of pigment.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 1 is that: the polyester resin is a saturated polyester resin, with a number-average molecular weight of 15000 g / mol, a glass transition temperature of 60 °C, an acid value of 3 - 5 KOH mg / g, and a hydroxyl value of 5 - 10 KOH mg / g. It is purchased from SK Saturated Polyester Resin SKYBON EW-312 of South Korea.

[0104] Comparative Example 3

[0105] The difference between this comparative example and Example 1 is that: the epoxy resin is a glycidyl ether type epoxy resin, with an epoxy equivalent of 120 - 150 g / eq and a viscosity of 7000 - 10000 cps at 25 °C. It is purchased from Nan Ya Epoxy Resin 901.

[0106] Comparative Example 4

[0107] The difference between this comparative example and Example 1 is that: the ABS resin has a molecular weight of 80,000 Da, the mass fraction of butadiene in the ABS resin is 25%, the mass fraction of acrylonitrile is 35%, and the mass fraction of styrene is 40%; the melt index of the ABS resin at 220 °C and 10 kg is 37 g / 10 min. It is purchased from Formosa Plastics (Ningbo) Co., Ltd.

[0108] Comparative Example 5

[0109] The difference between this comparative example and Example 1 is that: the epoxy resin is replaced with an ethylene-octene copolymer, and the specific gravity of the ethylene-octene copolymer is 0.88 - 0.92 g / cm 3 , and the melt index of the ethylene-octene copolymer at 190 °C / 2.16 kg is 0.5 - 0.8 g / 10 min. It is purchased from Dow of the United States.

[0110] Comparative Example 6

[0111] The difference between this comparative example and Example 1 is that: the ABS resin is replaced with an ethylene-vinyl acetate copolymer, and the vinyl acetate content in the ethylene-vinyl acetate copolymer is 20 - 23 wt%; the melt index of the ethylene-vinyl acetate copolymer is 6 - 7 g / 10 min. It is purchased from DuPont of the United States.

[0112] Comparative Example 7

[0113] The difference between this comparative example and Example 1 is that: the plasticizer is dibutyl phthalate.

[0114] Comparative Example 8

[0115] The difference between this comparative example and Example 1 is as follows: The preparation method of the modified filler is as follows: Alumina, silicon carbide and boron nitride with a mass ratio of 1:1.6:0.7 are mixed to obtain a mixed powder; the mixed powder with a mass ratio of 1:10:0.03, 55 wt% ethanol aqueous solution and silane coupling agent KH550 are mixed and reacted at 45 °C for 2 h, filtered, washed and dried to obtain the modified filler.

[0116] Comparative Example 9

[0117] The difference between this comparative example and Example 1 is as follows: The particle size of alumina is 100 - 200 nm, and the specific surface area is 3 - 8 m 2 / g; the particle size of silicon carbide is 1200 - 1600 nm, and the average specific surface area is 14 m 2 / g; the particle size of boron nitride is 30 - 40 μm, and the specific surface area is 3 - 16 m 2 / g. Alumina is purchased from Zhejiang Zhitaina Micro New Materials Co., Ltd.; silicon carbide is purchased from Jinlei Technology; boron nitride is purchased from Shandong Jingyi New Materials Co., Ltd.

[0118] Performance Test

[0119] The physical properties of the foamed materials obtained in Examples 1 - 2 and Comparative Examples 1 - 9 were measured, and the test data are shown in Table 1.

[0120] 1. Elasticity: ASTM D2632;

[0121] 2. Tear strength: GB / T 8948 - 2008;

[0122] 3. Elongation at break: GB / T 8948 - 2008;

[0123] 4. Compression set: GB / T 10653 - 2001; calculation formula = (thickness before compression - thickness after compression) / thickness before compression * 100%;

[0124] 5. Hardness: GB / T 3903.4 - 2017.

[0125] Table 1 Performance Test Results

[0126]

[0127] It can be seen from the results that the foamed materials in Examples 1 - 2 have excellent comprehensive performance, can improve the elasticity of the pick racket and extend the service life. From Comparative Examples 1 - 9, it can be seen that by changing the preparation conditions, the performance decreases to varying degrees.

[0128] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high-elasticity pickleball racket, characterized in that: The racket body comprises a racket body, a side strip and a handle; the racket body is provided with a racket core, the racket core is provided with a groove, and the groove is arranged in a horizontal, vertical or oblique direction; and the groove is filled with elastic material; The preparation method of the elastic material comprises: (1) Preparing a plasticizer: mixing 27-34 parts of propylene-1,2,3-tricarboxylic acid, 48-55 parts of 2-ethylhexanol, 48-57 parts of toluene and 2.5-3.2 parts of p-toluenesulfonic acid according to weight parts, and carrying out an esterification reaction at 400-500 rpm with stirring at a temperature and time of 120-130° C. for 5-7 hours to obtain a mixed solution; adding an equal volume of an aqueous alkaline solution to the mixed solution for reaction at a temperature and time of 47-53° C. for 20-30 minutes, extracting to obtain an upper organic phase, distilling and purifying, decolorizing and filtering to obtain a plasticizer; The structure of plasticizer is as follows: (2) Weigh the following foaming material components in parts by weight: 43-50 parts of polyester resin, 28-33 parts of epoxy resin, 20-25 parts of ABS resin, 6-10 parts of modified filler, 3-5 parts of plasticizer, 0.5-1.4 parts of lubricant, 1-1.5 parts of active agent, 0.8-1.4 parts of cross-linking agent, 2-3 parts of foaming agent and 2-4 parts of pigment; (3) Preparation of foaming material: polyester resin, epoxy resin, ABS resin, modified filler, lubricant, plasticizer, active agent and pigment are mixed, heated to 113-118°C and kneaded for 10-15 minutes; then a crosslinking agent and a foaming agent are added, the temperature is continued to be raised to 120-125°C and kneaded for 4-7 minutes to obtain a mixture, granulated, and injected into a mold at a mold temperature of 185-190°C. After adding sulfur, the mixture is formed and shaped at a constant temperature to obtain a foaming material; (4) Using carbon fiber to wrap the foam material to obtain an elastic material; The preparation method of the modified filler is: (1) mixing aluminum oxide, silicon carbide and boron nitride in a mass ratio of 1:1.4-1.8:0.3-0.9 to obtain a mixed powder; (2) According to parts by mass, 15 parts of mixed powder, 140-150 parts of water, 0.4-0.8 parts of 3-amino-1,2,4-triazole-5-thiol and 0.6-0.8 parts of 70-75wt% methanesulfonic acid aqueous solution are mixed to obtain a mixed solution A, and 0.24-0.27 parts of sodium nitrite and 15-18 parts of water are mixed to obtain a mixed solution B; the mixed solution A and the mixed solution B are mixed and stirred at 70-75°C for 60-80 minutes; cooled to room temperature, the pH is adjusted to 8-8.5 with 0.1-0.3 mol / L NaOH aqueous solution, the solid is collected by filtration, washed and dried to obtain a modified filler.

2. The high-elasticity pickleball racket according to claim 1, characterized in that: The polyester resin is a saturated polyester resin with a number average molecular weight of 6×10 3 Da, glass transition temperature is 46°C, acid value is 5KOHmg / g, and hydroxyl value is 619KOHmg / g.

3. The high-elasticity pickleball racket according to claim 1, characterized in that: The epoxy resin is a glycidyl ether epoxy resin with an epoxy equivalent of 180-190 g / eq and a viscosity of 11000-15000 cps at 25°C.

4. The high-elasticity pickleball racket according to claim 1, characterized in that: The molecular weight of the ABS resin is 120,000 Da, the mass fraction of butadiene in the ABS resin is 45%, the mass fraction of acrylonitrile is 25%, and the mass fraction of styrene is 30%; the melt index of the ABS resin at 220° C. and 10 kg is 43 g / 10 min.

5. The high-elasticity pickleball racket according to claim 1, characterized in that: The particle size of alumina is 30-60nm, and the specific surface area is 10-20m 2 / g; the particle size of silicon carbide is 500-800nm, and the average specific surface area is 20m 2 / g; Boron nitride particle size is 2-20μm, specific surface area is 6-25 m 2 / g.

6. The high-elasticity pickleball racket according to claim 1, characterized in that: The lubricant is low-density polyethylene wax, and the viscosity of the low-density polyethylene wax at 140° C. is 450 cps and the density is 0.93 g / cm 3 , particle size is 1410μm.

7. The high-elasticity pickleball racket according to claim 1, characterized in that: The cross-linking agent is dicumyl peroxide.

8. The high-elasticity pickleball racket according to claim 1, characterized in that: The foaming agent is azodicarbonamide.

9. The high-elasticity pickleball racket according to claim 1, characterized in that: The alkaline aqueous solution is a sodium carbonate aqueous solution, and the mass fraction of the solute in the alkaline aqueous solution is 4-7%.

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