Anti-aging elastic composite rubber for table tennis bat and preparation method thereof

Abstract

The application discloses an anti-aging elastic composite rubber for table tennis bats and a preparation method thereof, and belongs to the technical field of rubber materials. A surfactant, a silane coupling agent modified composite filler, 1,3-butadiene solution and acrylonitrile are mixed and stirred to form a mixed emulsion; the mixed emulsion is mixed with an initiator to obtain a nitrile rubber prepolymer; the nitrile rubber prepolymer, a vulcanizing agent and an accelerator are mixed to obtain a mixed rubber; and the mixed rubber is subjected to vulcanization treatment to obtain the elastic composite rubber. The silane coupling agent modified composite filler, 1,3-butadiene solution and acrylonitrile are first mixed and reacted to obtain the nitrile rubber prepolymer, and then the nitrile rubber prepolymer is subjected to mixing and vulcanization treatment, so that the elastic composite rubber with good mechanical properties and anti-aging performance is obtained.

Description

Technical Field

[0001] This invention belongs to the field of rubber materials technology, specifically relating to an anti-aging elastic composite rubber for table tennis rackets and its preparation method. Background Technology

[0002] A table tennis racket is a composite material made of rubber, sponge, and blade bonded together with adhesive. The rubber, as the core component of the racket, comes into direct contact with the table tennis ball, and its material, structure, and performance determine key factors such as speed, spin, and control during a shot. Therefore, the rubber needs to possess elasticity, suitable hardness, and a certain degree of aging resistance. Rubber is a high-quality polymer material with high elasticity and viscoelasticity, widely used in the automotive, aerospace, construction, medical, food, and electronics industries. my country is a major rubber producer globally, ranking first in both rubber consumption and rubber product output. Rubber materials are mainly divided into two categories: natural rubber and synthetic rubber. Natural rubber is extracted from rubber trees, rubber grass, and other plants and processed; its main component is cis-1,4-polyisoprene. Synthetic rubber is prepared by polymerization reactions of various monomers, mainly including fluororubber, styrene-butadiene rubber, ethylene propylene rubber, and silicone rubber. Due to improvements in the composition and structure of rubber, synthetic rubber exhibits excellent properties in terms of high-temperature resistance, aging resistance, and corrosion resistance. Rubber materials possess excellent elasticity, making them promising candidates for use in the manufacture of table tennis racket rubbers. However, traditional natural rubber, without modification, struggles to achieve optimal performance.

[0003] Nitrile butadiene rubber (NBR) is a synthetic rubber obtained by copolymerizing butadiene and acrylonitrile, possessing good wear resistance and heat resistance. However, due to the large number of unsaturated olefin segments in its molecular structure, NBR exhibits relatively poor aging resistance. Current technologies attempt to improve NBR's aging resistance by introducing antioxidants; however, traditional antioxidants have relatively small molecular weights and high volatility, especially during processing or use, easily diffusing from the rubber matrix to the surface, significantly reducing their antioxidant efficacy.

[0004] Therefore, it is of great significance to modify nitrile rubber to give it good aging resistance when used in table tennis racket rubber. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention first involves mixing and reacting a silane coupling agent-modified composite filler, a 1,3-butadiene solution, and acrylonitrile to obtain a nitrile rubber prepolymer. Then, through compounding and vulcanization, an elastic composite rubber with good mechanical properties and anti-aging properties is obtained, thereby solving the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following: One objective of this invention is to provide a method for preparing an anti-aging elastic composite rubber for table tennis rackets, the method comprising the following steps: Surfactant, silane coupling agent modified composite filler, 1,3-butadiene solution and acrylonitrile are mixed and stirred in a weight ratio of 0.01~0.03:0.4~0.5:5~9:2~4 to form a mixed emulsion; A nitrile rubber prepolymer was obtained by mixing and catalyzing a mixed emulsion and an initiator at a weight ratio of 1:0.003~0.004. Nitrile rubber prepolymer, vulcanizing agent and accelerator are mixed in a weight ratio of 1~2:0.02~0.03:0.01~0.015 to obtain a compound rubber. The compound rubber is then vulcanized to obtain an elastic composite rubber.

[0006] Furthermore, the surfactant is composed of sodium dodecylbenzenesulfonate and AEO-10 ​​in a weight ratio of 0.5:1.

[0007] Furthermore, the preparation method of the silane coupling agent modified composite filler includes the following steps: Inorganic filler, antioxidant, and anhydrous acetone were mixed and dispersed in a weight ratio of 5:0.1~0.2:50~60 to obtain a dispersion. A pretreated hydrolysate was obtained by mixing silane coupling agent, anhydrous ethanol, and deionized water in a weight ratio of 0.2~0.3:0.6~0.7:0.1 and heating the mixture. The dispersion and pretreated hydrolysate were mixed at a ratio of 1:0.8~0.9 and heated to obtain silane coupling agent modified composite filler.

[0008] Furthermore, the inorganic filler includes nano-silica.

[0009] Furthermore, the particle size of the nano-silica is 60 nm.

[0010] Furthermore, the antioxidant is a hindered phenolic antioxidant, including antioxidant 1010 or antioxidant 1076.

[0011] Furthermore, the conditions for mixing and dispersing include an ultrasonic power of 300W~400W and a dispersion time of 15min~20min.

[0012] Furthermore, the silane coupling agent includes vinyltrimethoxysilane or vinyltriethoxysilane.

[0013] Furthermore, the conditions for the heating reaction of the silane coupling agent, anhydrous ethanol, and deionized water include a temperature of 30°C to 40°C, a pH of 4.5 to 5, and a heating time of 40 min to 50 min.

[0014] Furthermore, the conditions for heating the mixture of the dispersion and the pretreated hydrolysate include a temperature of 60°C to 70°C and a heating time of 4 to 5 hours.

[0015] Furthermore, the molar concentration of the 1,3-butadiene solution is 1 mol / L to 1.5 mol / L.

[0016] Furthermore, the mixing and stirring conditions for the surfactant, silane coupling agent modified composite filler, 1,3-butadiene solution and acrylonitrile include a stirring speed of 800 r / min to 1000 r / min and a stirring time of 10 min to 15 min.

[0017] Furthermore, the initiator includes potassium persulfate.

[0018] Furthermore, the conditions for the mixed emulsion and initiator to be mixed and catalyzed include a catalytic temperature of 30°C to 35°C, a catalytic pressure of 2MPa to 3MPa, and a catalytic time of 7h to 8h.

[0019] Furthermore, the vulcanizing machine includes sulfur, and the accelerator includes dibenzothiazole disulfide.

[0020] Furthermore, the mixing conditions include a mixing speed of 80 r / min, a mixing temperature of 60℃, and a mixing time of 10 min.

[0021] Furthermore, the conditions for the vulcanization treatment include a vulcanization temperature of 150°C, a vulcanization pressure of 13 MPa, and a vulcanization time of 15 min.

[0022] The second objective of this invention is to provide an anti-aging elastic composite rubber for table tennis rackets.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses an inorganic filler with UV resistance and enhanced mechanical properties as one of the modifying materials, and an antioxidant with antioxidant properties as another modifying material. The silanol groups generated after the hydrolysis of the silane coupling agent condense and crosslink with the hydroxyl groups on the surface of the inorganic filler and the hydroxyl groups on the antioxidant structure to form siloxane bonds. These two are then covalently linked to form a silane coupling agent modified composite filler. This composite filler possesses the carbon-carbon double bonds of the silane coupling agent. Through this carbon-carbon double bond structure, it undergoes a carbon-carbon double bond condensation copolymerization reaction with 1,3-butadiene and acrylonitrile, the basic raw materials for synthesizing nitrile rubber. This indirectly introduces the inorganic filler and antioxidant into the nitrile rubber prepolymer through chemical crosslinking, greatly reducing the adverse effects of the inorganic filler's small particle size and tendency to agglomerate, which affects the mechanical properties of the rubber, and the antioxidant's high volatility, which leads to poor modification effects. The synergistic effect of these two modifying materials results in an elastic composite rubber with not only good anti-aging properties but also excellent mechanical properties. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0025] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0026] Preparation Example 1: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: Five parts by weight of 60 nm nano-silica, 0.1 parts by weight of antioxidant 1010, and 50 parts by weight of anhydrous acetone were weighed and added to a flask. The flask was then placed in an ultrasonic disperser, the ultrasonic power was adjusted to 300 W, and the dispersion time was controlled to 15 min. The dispersion was then prepared for later use. Two parts by weight of vinyltrimethoxysilane, 0.6 parts by weight of anhydrous ethanol, and 0.1 parts by weight of deionized water were weighed and added to a reaction flask. The pH was adjusted to 4.5 with acetic acid, and the flask was placed in a 30 °C water bath and stirred at 200 r / min for 40 min for hydrolysis. After hydrolysis, the mixture was cooled to 20 °C to obtain a pretreated hydrolysate for later use. One part by weight of the dispersion and 0.8 parts by weight of the pretreated hydrolysate were weighed and mixed. Nitrogen gas was then introduced for 5 min to purge the air. The mixture was then heated and stirred in a 60 °C water bath at 100 r / min for 4 h. After the reaction was completed, the precipitate was collected by centrifugation and filtration. The precipitate was first washed with anhydrous ethanol, and then washed with deionized water until the pH of the wash water was neutral. Then it was placed in a vacuum drying oven at 60°C for 12 hours to obtain the silane coupling agent modified composite filler.

[0027] Preparation Example 2: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: Five parts by weight of 60 nm nano-silica, 0.15 parts by weight of antioxidant 1010, and 55 parts by weight of anhydrous acetone were weighed and added to a flask. The flask was then placed in an ultrasonic disperser, the ultrasonic power was adjusted to 350 W, and the dispersion time was controlled to 18 min. The dispersion was then prepared for later use. 0.25 parts by weight of vinyltrimethoxysilane, 0.65 parts by weight of anhydrous ethanol, and 0.1 parts by weight of deionized water were weighed and added to a reaction flask. The pH was adjusted to 4.5 with acetic acid, and the flask was placed in a water bath at 35 °C and stirred at 200 r / min for 45 min for hydrolysis. After hydrolysis, the mixture was cooled to 20 °C to obtain a pretreated hydrolysate for later use. One part by weight of the dispersion and 0.85 parts by weight of the pretreated hydrolysate were weighed and mixed. Nitrogen gas was then introduced for 5 min to purge the air. The mixture was then heated and stirred in a water bath at 65 °C at 100 r / min for 4.5 h. After the reaction was completed, the precipitate was collected by centrifugation and filtration. The precipitate was first washed with anhydrous ethanol, and then washed with deionized water until the pH of the wash water was neutral. Then it was placed in a vacuum drying oven at 60°C for 12 hours to obtain the silane coupling agent modified composite filler.

[0028] Preparation Example 3: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: Five parts by weight of 60 nm nano-silica, 0.2 parts by weight of antioxidant 1076, and 60 parts by weight of anhydrous acetone were weighed and added to a flask. The flask was then placed in an ultrasonic disperser, the ultrasonic power was adjusted to 400 W, and the dispersion time was controlled to 20 min. The dispersion was then prepared for later use. Three parts by weight of vinyltriethoxysilane, 0.7 parts by weight of anhydrous ethanol, and 0.1 parts by weight of deionized water were weighed and added to a reaction flask. The pH was adjusted to 5 with acetic acid, and the flask was placed in a 40 °C water bath and stirred at 200 r / min for 50 min for hydrolysis. After hydrolysis, the mixture was cooled to 20 °C to obtain a pretreated hydrolysate for later use. One part by weight of the dispersion and 0.9 parts by weight of the pretreated hydrolysate were weighed and mixed. Nitrogen gas was then introduced for 5 min to purge the air. The mixture was then heated and stirred in a 70 °C water bath at 100 r / min for 5 h. After the reaction was completed, the precipitate was collected by centrifugation and filtration. The precipitate was first washed with anhydrous ethanol, and then washed with deionized water until the pH of the wash water was neutral. Then it was placed in a vacuum drying oven at 60°C for 12 hours to obtain the silane coupling agent modified composite filler.

[0029] Preparation Example 4: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: The 60 nm nano-silica particles in Preparation Example 3 were replaced with 30 nm nano-silica particles, and the rest of the preparation process remained the same as in Preparation Example 3.

[0030] Preparation Example 5: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: In Preparation Example 3, antioxidant 1076 was replaced with antioxidant 168, and the rest of the preparation process remained the same as in Preparation Example 3.

[0031] Preparation Example 6: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: Five parts by weight of 60 nm nano-silica, 0.2 parts by weight of antioxidant 1076, and 60 parts by weight of anhydrous acetone were weighed and added to a flask. The flask was then placed in an ultrasonic disperser, the ultrasonic power was adjusted to 400 W, and the dispersion time was controlled to 20 min. The dispersion was then prepared for use. Three parts by weight of vinyltriethoxysilane, 0.7 parts by weight of anhydrous ethanol, and 0.1 parts by weight of deionized water were weighed and added to a reaction flask. The pH was adjusted to 5 with acetic acid, and the flask was placed in a 40 °C water bath and stirred at 200 r / min for 20 min for hydrolysis. After hydrolysis, the mixture was cooled to 20 °C to obtain a pretreated hydrolysate for use. One part by weight of the dispersion and 0.9 parts by weight of the pretreated hydrolysate were weighed and mixed. Nitrogen gas was then introduced for 5 min to purge the air. The mixture was then heated and stirred in a 70 °C water bath at 100 r / min for 5 h. After the reaction was completed, the precipitate was collected by centrifugation and filtration. The precipitate was first washed with anhydrous ethanol, and then washed with deionized water until the pH of the wash water was neutral. Then it was placed in a vacuum drying oven at 60°C for 12 hours to obtain the silane coupling agent modified composite filler.

[0032] Preparation Example 7: The preparation method of silane coupling agent modified composite filler specifically includes the following steps: Five parts by weight of 60 nm nano-silica, 0.2 parts by weight of antioxidant 1076, and 60 parts by weight of anhydrous acetone were weighed and added to a flask. The flask was then placed in an ultrasonic disperser, the ultrasonic power was adjusted to 400 W, and the dispersion time was controlled to 70 min. The dispersion was then prepared for use. Three parts by weight of vinyltriethoxysilane, 0.7 parts by weight of anhydrous ethanol, and 0.1 parts by weight of deionized water were weighed and added to a reaction flask. The pH was adjusted to 5 with acetic acid, and the flask was placed in a 40 °C water bath and stirred at 200 r / min for 20 min for hydrolysis. After hydrolysis, the mixture was cooled to 20 °C to obtain a pretreated hydrolysate for use. One part by weight of the dispersion and 0.9 parts by weight of the pretreated hydrolysate were weighed and mixed. Nitrogen gas was then introduced for 5 min to purge the air. The mixture was then heated and stirred in a 70 °C water bath at 100 r / min for 5 h. After the reaction was completed, the precipitate was collected by centrifugation and filtration. The precipitate was first washed with anhydrous ethanol, and then washed with deionized water until the pH of the wash water was neutral. Then it was placed in a vacuum drying oven at 60°C for 12 hours to obtain the silane coupling agent modified composite filler.

[0033] Example 1: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: Five parts by weight of 1,3-butadiene solution (molar concentration 1 mol / L) and two parts by weight of acrylonitrile were weighed and mixed. Then, 0.01 parts by weight of surfactant (composed of 0.5 parts by weight of sodium dodecylbenzenesulfonate and 1 part by weight of AE0-15) and 0.4 parts by weight of the silane coupling agent modified composite filler obtained in Preparation Example 1 were added. The mixture was then stirred and dispersed in a high-speed disperser at a speed of 800 r / min for 10 min to obtain a mixed emulsion. 0.003 times the weight of potassium persulfate was weighed and added together with the mixed emulsion to... The mixture was stirred evenly in the reactor, then nitrogen gas was introduced to completely purge the air. The reactor was then closed, and nitrogen gas was continued to be introduced until the pressure inside the reactor reached 2 MPa. The reactor temperature was then controlled at 30℃, and the catalytic reaction was carried out for 7 hours. After the reaction was completed, the mixture was removed and dried in a vacuum drying oven at 60℃ to obtain nitrile rubber prepolymer. One part by weight of nitrile rubber prepolymer, 0.02 parts by weight of sulfur, and 0.01 parts by weight of dibenzothiazole disulfide were weighed and added to a two-roll mill preheated to 60℃. The speed of the two-roll mill was adjusted to 80 r / min, and then the mixture was kneaded for 10 minutes. After the resulting compound was left to stand for 24 hours, it was poured into a flat vulcanizing machine and vulcanized at a vulcanization temperature of 150℃ and a vulcanization pressure of 13 MPa for 15 minutes. Finally, it was allowed to cool naturally to room temperature to obtain an elastic composite rubber.

[0034] Example 2: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: Weigh 7 parts by weight of 1,3-butadiene solution (molar concentration 1.2 mol / L) and 3 parts by weight of acrylonitrile and mix them. Then add 0.02 parts by weight of surfactant (composed of 0.5 parts by weight of sodium dodecylbenzenesulfonate and 1 part by weight of AE0-15) and 0.45 parts by weight of the silane coupling agent modified composite filler obtained in Preparation Example 2. Then mix and disperse in a high-speed disperser at a speed of 900 r / min for 12 min to obtain a mixed emulsion. Weigh 0.003 times the weight of the mixed emulsion of potassium persulfate and add it together with the mixed emulsion to the reaction mixture. The mixture was stirred thoroughly in the reactor, then nitrogen gas was introduced to completely purge the air. The reactor was then closed, and nitrogen gas was continued to be introduced until the pressure inside the reactor reached 2 MPa. The reactor temperature was then controlled at 30℃, and the catalytic reaction was carried out for 7.5 hours. After the reaction was completed, the mixture was removed and dried in a vacuum drying oven at 60℃ to obtain nitrile rubber prepolymer. 1.5 parts by weight of nitrile rubber prepolymer, 0.025 parts by weight of sulfur, and 0.01 parts by weight of dibenzothiazole disulfide were weighed and added to a two-roll mill preheated to 60℃. The speed of the two-roll mill was adjusted to 80 r / min, and then the mixture was kneaded for 10 minutes. After the resulting compound was left to stand for 24 hours, it was poured into a flat vulcanizing machine and vulcanized at a vulcanization temperature of 150℃ and a vulcanization pressure of 13 MPa for 15 minutes. Finally, it was allowed to cool naturally to room temperature to obtain an elastic composite rubber.

[0035] Example 3: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: Nine parts by weight of a 1,3-butadiene solution (molar concentration 1.5 mol / L) and four parts by weight of acrylonitrile were weighed and mixed. Then, 0.03 parts by weight of a surfactant (composed of 0.5 parts by weight of sodium dodecylbenzenesulfonate and 1 part by weight of AE0-15) and 0.5 parts by weight of the silane coupling agent modified composite filler obtained in Preparation Example 3 were added. The mixture was then stirred and dispersed in a high-speed disperser at a speed of 1000 r / min for 15 min to obtain a mixed emulsion. 0.004 times the weight of the mixed emulsion of potassium persulfate was weighed and added together with the mixed emulsion. The mixture was stirred evenly in a reactor, and then nitrogen gas was introduced to completely purge the air. The reactor was then closed, and nitrogen gas was continued to be introduced until the pressure inside the reactor reached 3 MPa. The reactor temperature was then controlled at 35℃, and the catalytic reaction was carried out for 8 hours. After the reaction was completed, the mixture was removed and dried in a vacuum drying oven at 60℃ to obtain nitrile rubber prepolymer. Two parts by weight of nitrile rubber prepolymer, 0.03 parts by weight of sulfur, and 0.015 parts by weight of dibenzothiazole disulfide were weighed and added to a two-roll mill preheated to 60℃. The speed of the two-roll mill was adjusted to 80 r / min, and then the mixture was kneaded for 10 minutes. After the resulting compound was left to stand for 24 hours, it was poured into a flat vulcanizing machine and vulcanized at a vulcanization temperature of 150℃ and a vulcanization pressure of 13 MPa for 15 minutes. Finally, it was allowed to cool naturally to room temperature to obtain an elastic composite rubber.

[0036] Comparative Example 1: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: The silane coupling agent modified composite filler in Example 3 was replaced with the silane coupling agent modified composite filler obtained in Preparation Example 4, and the rest of the preparation process was the same as in Example 3.

[0037] Comparative Example 2: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: The silane coupling agent modified composite filler in Example 3 was replaced with the silane coupling agent modified composite filler obtained in Preparation Example 5, and the rest of the preparation process was the same as in Example 3.

[0038] Comparative Example 3: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: The silane coupling agent modified composite filler in Example 3 was replaced with the silane coupling agent modified composite filler obtained in Preparation Example 6, and the rest of the preparation process was the same as in Example 3.

[0039] Comparative Example 4: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: The silane coupling agent modified composite filler in Example 3 was replaced with the silane coupling agent modified composite filler obtained in Preparation Example 7, and the rest of the preparation process was the same as in Example 3.

[0040] Comparative Example 5: A method for preparing an anti-aging elastic composite rubber for table tennis rackets, specifically including the following steps: Two parts by weight of nitrile rubber NBR3306G, 0.5 parts by weight of the silane coupling agent modified composite filler obtained in Preparation Example 3, 0.03 parts by weight of sulfur, and 0.015 parts by weight of dibenzothiazole disulfide were weighed and added to a two-roll mill preheated to 60°C. The speed of the two-roll mill was adjusted to 80 r / min, and then the mixture was kneaded for 10 min. After the resulting compound was left to stand for 24 h, it was poured into a flat vulcanizing machine and vulcanized at a vulcanization temperature of 150°C and a vulcanization pressure of 13 MPa for 15 min. Finally, it was naturally cooled to room temperature to obtain an elastic composite rubber.

[0041] The elastic composite rubbers obtained in Examples 1-3 and Comparative Examples 1-5 were prepared into samples of 50mm×50mm×4mm, and then tensile strength was tested using an electronic universal tensile testing machine at a tensile rate of 500 mm / min. The results are shown in Table 1 below.

[0042] Table 1 Mechanical Properties The elastic composite rubbers obtained in Examples 1-3 and Comparative Examples 1-5 were subjected to thermal oxidation aging tests according to GB / T 3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air". The aging temperature was 100℃ and the aging time was 90h. Then, the tensile strength was tested using an electronic universal tensile testing machine at a tensile rate of 500 mm / min. The results are shown in Table 2 below.

[0043] Table 2 Aging resistance mechanical properties The following conclusions can be drawn from the test results in Tables 1 and 2 above: (1) As can be seen from Examples 1 to 3, the elastic composite rubber prepared by the present invention has good anti-aging and mechanical properties.

[0044] (2) Comparative Example 1 shows that the mechanical properties and anti-aging properties of the prepared elastic composite rubber are poor. This may be because the particle size of the nano silica is too small. The preparation method of this system may not be able to effectively modify the surface of the nano silica, which affects the preparation of the silane coupling agent modified composite filler, and thus the final elastic composite rubber has poor performance.

[0045] (3) Comparative Example 2 shows that the mechanical properties and anti-aging properties of the prepared elastic composite rubber are poor. This may be because antioxidant 168 does not have hydroxyl functional groups in its structure, which makes it impossible to form siloxane bonds with the silanol produced by the hydrolysis of silane coupling agent. As a result, antioxidant 168 cannot form a connection with nano silica. Relying solely on nano silica, the final elastic composite rubber has poor performance.

[0046] (4) Comparative Examples 3 and 4 show that the mechanical properties and anti-aging properties of the prepared elastic composite rubber are poor. This may be because in this system, it is necessary to rely on the hydrolysis of silane coupling agent to generate silanol groups in order to modify nano silica and antioxidant 1076. However, if the hydrolysis time of silane coupling agent is too short, the number of silanol groups generated by hydrolysis may be less, resulting in poor performance of the prepared elastic composite rubber. If the hydrolysis time is too long, the silane coupling agent is prone to self-polymerization, making it difficult to modify nano silica and antioxidant 1076, resulting in poor performance of the final prepared elastic composite rubber.

[0047] (5) Comparative Example 5 shows that the mechanical properties and anti-aging properties of the prepared elastic composite rubber are poor. This may be because if the prepared silane coupling agent modified composite filler is directly mixed with nitrile rubber and vulcanized, the poor compatibility with nitrile rubber may result in poor direct mixing and modification effect, which in turn leads to poor performance of the final prepared elastic composite rubber.

[0048] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing an anti-aging elastic composite rubber for table tennis rackets, characterized in that, The preparation method includes the following steps: Surfactant, silane coupling agent modified composite filler, 1,3-butadiene solution and acrylonitrile are mixed and stirred in a weight ratio of 0.01~0.03:0.4~0.5:5~9:2~4 to form a mixed emulsion; A nitrile rubber prepolymer was obtained by mixing and catalyzing a mixed emulsion and an initiator at a weight ratio of 1:0.003~0.

004. Nitrile rubber prepolymer, vulcanizing agent and accelerator are mixed in a weight ratio of 1~2:0.02~0.03:0.01~0.015 to obtain a compound rubber, and the compound rubber is vulcanized to obtain an elastic composite rubber. The preparation method of the silane coupling agent modified composite filler includes the following steps: Inorganic filler, antioxidant, and anhydrous acetone were mixed and dispersed in a weight ratio of 5:0.1~0.2:50~60 to obtain a dispersion. A pretreated hydrolysate was obtained by mixing silane coupling agent, anhydrous ethanol, and deionized water in a weight ratio of 0.2~0.3:0.6~0.7:0.1 and heating the mixture. The dispersion and pretreated hydrolysate were mixed at a ratio of 1:0.8~0.9 and heated to obtain a silane coupling agent modified composite filler; The inorganic filler is nano-silica with a particle size of 60nm; The hindered phenolic antioxidant is antioxidant 1010 or antioxidant 1076; The silane coupling agent is vinyltrimethoxysilane or vinyltriethoxysilane; The conditions for the heating reaction of the silane coupling agent, anhydrous ethanol and deionized water include a temperature of 30℃~40℃, a pH of 4.5~5 and a heating time of 40min~50min.

2. The method for preparing an anti-aging elastic composite rubber for table tennis rackets according to claim 1, characterized in that, The surfactant is composed of sodium dodecylbenzenesulfonate and AEO-10 ​​in a weight ratio of 0.5:

1.

3. The method for preparing an anti-aging elastic composite rubber for table tennis rackets according to claim 1, characterized in that, The conditions for heating the mixture of the dispersion and the pretreated hydrolysate include a temperature of 60℃~70℃ and a heating time of 4h~5h.

4. The method for preparing an anti-aging elastic composite rubber for table tennis rackets according to claim 1, characterized in that, The conditions for the mixed emulsion and initiator catalysis include a catalytic temperature of 30℃~35℃, a catalytic pressure of 2MPa~3MPa, and a catalytic time of 7h~8h.

5. The method for preparing an anti-aging elastic composite rubber for table tennis rackets according to claim 1, characterized in that, The conditions for the vulcanization treatment include a vulcanization temperature of 150°C, a vulcanization pressure of 13 MPa, and a vulcanization time of 15 min.

6. A type of anti-aging elastic composite rubber for table tennis rackets, characterized in that, The elastic composite rubber is prepared by the method for preparing an anti-aging elastic composite rubber for a table tennis racket as described in any one of claims 1 to 5.

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