Modified PCR ABS material for ping-pong ball shells and its preparation method

Abstract

The application provides a modified PCR ABS material for table tennis shells and a preparation method thereof, which comprises the following components in parts by mass: low-flow PCR ABS resin: 30-40 parts, high-flow PCR ABS resin: 20-30 parts, large-particle-size ABS rubber powder: 10-15 parts, small-particle-size ABS rubber powder: 3-5 parts, SAN blend: 8-15 parts, and ABS new material: 0-20 parts; the low-flow PCR ABS resin has a melt index of 10-15 g / 10 min (220 DEG C x 10 kg); the high-flow PCR ABS resin has a melt index of 20-25 g / 10 min (220 DEG C x 10 kg); the large-particle-size ABS rubber powder has a particle size of 350-400 nm; and the small-particle-size ABS rubber powder has a particle size of 50-150 nm.

Description

Technical Field

[0001] This invention relates to the field of modified materials technology, and particularly to materials for ping-pong ball shells, specifically to modified PCR ABS materials for ping-pong ball shells and their preparation methods. Background Technology

[0002] The materials used for table tennis ball shells have evolved from celluloid and cellulose acetate to the now mainstream acrylonitrile-butadiene-styrene terpolymer (ABS). ABS plastic, with its excellent impact resistance, high strength, and good processability, has become an ideal alternative to celluloid and cellulose acetate.

[0003] Because table tennis balls need to withstand high-intensity hits from professional athletes, the requirements for material performance are extremely stringent. Therefore, almost all ball shells are currently made from virgin ABS produced by petrochemical companies. Post-consumer recycled ABS plastic (i.e., PCR ABS) is difficult to use directly in the manufacture of table tennis ball shells due to issues such as performance degradation and poor batch stability.

[0004] Therefore, this study aims to develop a modified PCR ABS material for recycling ABS waste from the dismantling of household appliances, so that its performance can reach the level of virgin ABS material, thereby expanding the application path of recycled plastics in high-performance sporting goods. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one of the disadvantages of the prior art and to provide a modified PCR ABS material for ping-pong ball shells and its preparation method.

[0006] To solve the above-mentioned technical problems, the present invention provides a modified PCR ABS material for ping-pong ball shells, characterized in that, by weight, it comprises the following components: low-flow PCR ABS resin: 30-40 parts, high-flow PCR ABS resin: 20-30 parts, large-particle-size ABS rubber powder: 10-15 parts, small-particle-size ABS rubber powder: 3-5 parts, SAN blend: 8-15 parts, and virgin ABS: 0-20 parts. The low-flow PCR ABS resin described above has a melt index of 10–15 g / 10 min (220℃ × 10 kg) and a density of 1.06–1.07 g / cm³. 3 The notched impact strength of the cantilever beam is 13–18 KJ / m. 2 ; The high-flow PCR ABS resin described above has a melt index of 20–25 g / 10 min (220℃ × 10 kg) and a density of 1.04–1.05 g / cm³. 3 The notched impact strength of the cantilever beam is 10–15 KJ / m.2 ; The particle size of the large-particle-size ABS rubber powder is 350-400 nm; The particle size of the small-particle-size ABS rubber powder is 50-150 nm.

[0007] Preferably, the SAN blend comprises, by weight, the following components: 40-60 parts of high-flow SAN resin, 30-40 parts of high-molecular-weight SAN resin, 10-20 parts of heat resistant agent, 0.1-0.5 parts of antioxidant, and 1-2 parts of lubricant.

[0008] Preferably, the high-flow SAN resin has a melt index of 150-250 g / 10 min (220℃×10 kg), the high-molecular-weight SAN resin has a molecular weight of 140,000-200,000, and a melt index of 8-15 g / 10 min (220℃×10 kg); the heat resistant agent is one or more of α-methylstyrene, N-phenylmaleimide, and styrene-maleic anhydride copolymer.

[0009] Preferably, the heat-resistant agent is N-phenylmaleimide.

[0010] Preferably, it also includes: 0.1 to 0.5 parts of antioxidant, 1 to 2 parts of lubricant, and 0.5 to 1 part of titanium dioxide.

[0011] Preferably, the antioxidant is one or both of hindered phenolic antioxidants and phosphite antioxidants; the hindered phenolic antioxidants include pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the phosphite antioxidants include triphenyl phosphate, tris(2,4-di-tert-butylphenyl) phosphite, and pentaerythritol di(2,4-di-tert-butylphenyl) phosphite; The titanium dioxide is anatase or rutile, preferably rutile titanium dioxide; The lubricant is any one or more of the following: silane polymer, butyl stearate, stearic acid, fatty acid salt, fatty acid amide, ethylene bis-stearamide, and polyethylene wax.

[0012] Preferably, by weight, it comprises the following components: 35 parts of low-flow PCR ABS resin, 25 parts of high-flow PCR ABS resin, 12 parts of large-particle-size ABS rubber powder, 4 parts of small-particle-size ABS rubber powder, 12 parts of SAN blend, 10 parts of virgin ABS material, 0.2 parts of antioxidant, 2 parts of lubricant, and 0.5 parts of titanium dioxide.

[0013] Preferably, the low-flow PCR ABS resin is white PCR ABS material recycled from refrigerator liners; the high-flow PCR ABS resin is unbleached PCR ABS material recycled from air conditioner internal components.

[0014] Preferably, the virgin ABS material has a melt flow index of 18–25 g / 10 min (220℃ × 10 kg) and a density of 1.04–1.05 g / cm³. 3 The notched impact strength of the cantilever beam is 17–25 KJ / m. 2 .

[0015] The present invention also provides a method for preparing a modified PCR ABS material for ping-pong ball shells, characterized by the following steps: melt-blending and extruding the components used to prepare the SAN blend to prepare the SAN blend; and melt-blending and extruding the components used to prepare the modified PCR ABS material to prepare the modified PCR ABS material.

[0016] The beneficial effects of the modified PCR ABS material for ping-pong ball shells and its preparation method of the present invention are as follows: By adding a high proportion of PCR ABS material, the ABS plastic recycled from household appliances is given a new lease on life in ping-pong balls, which has positive environmental significance. The PCR ABS material selected in this invention is derived from the internal parts of discarded household appliances and is almost uncontaminated during use. Therefore, it has high purity and good batch stability, making it suitable as a material for ping-pong ball shells.

[0017] The PCR ABS selected in this invention is a blend of low-flow refrigerator white inner liner material and high-flow air conditioner internal component recycled material, which reduces the amount of titanium dioxide required for dyeing during the preparation of ping-pong ball material. At the same time, the blend of the two recycled materials effectively improves the material's fluidity while taking into account its impact performance, which is conducive to better injection molding of ping-pong balls and lower internal stress. Compared to virgin ABS, PCR ABS materials are affected by aging to some extent, especially the rubber phase, which cross-links and hardens due to aging, losing elasticity and reducing the impact strength of the material. This invention improves the impact strength of PCR ABS by adding more high-quality ABS powder, especially by introducing a blend of high-quality rubber powder with different particle sizes. The larger particle size provides higher elasticity, while the smaller particle size can stop the expansion of streaks when encountering higher breaking energy, thus improving the impact resistance of the ping-pong ball. At the same time, the blending of large and small particle sizes is beneficial for mixing the rubber powder and the matrix ABS resin, resulting in better flow properties.

[0018] The rigidity of the material is further enhanced by introducing a high-rigidity SAN blend through a two-step process. The three components are uniformly mixed under high shear conditions by combining high-flow SAN, high-molecular-weight SAN, and a small amount of heat-resistant agent. This results in a SAN blend with high-flow SAN as the matrix and high-molecular-weight SAN as the high-rigidity anchor. The presence of the heat-resistant agent increases steric hindrance, making the high-rigidity SAN blend more effective at high temperatures after being added to the material formulation in the second step. This leads to lower thermal deformation and smaller roundness deviation in the subsequent high-temperature expansion and shaping process of the ping-pong ball. In addition, due to the increased rigidity, the ball shell deforms less under the same hitting force, resulting in less energy dissipation and greater elasticity. The prepared ping-pong ball has better speed and explosive power. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0020] This invention focuses on the recycling of ABS waste plastics from the dismantling of household appliances. By utilizing recycling, sorting, and modification technologies, a modified PCR ABS material for ping-pong ball shells has been prepared. Its performance can reach the level of existing virgin ABS materials and can be approved by the International Table Tennis Federation (ITTF) standards. The rigidity of the ball is better than that of virgin ABS balls, and it has superior rebound performance.

[0021] Preparation of high-rigidity SAN blends The raw materials are weighed as follows by weight: 50 parts high-flow SAN resin, 35 parts high-molecular-weight SAN resin, 14 parts heat resistant agent, 0.2 parts antioxidant, and 0.8 parts lubricant. The high-flow SAN resin is of the brand name Chimei 178HF, with a melt index of 160 g / 10 min (220℃ × 10 kg). The high-molecular-weight SAN resin is of the brand name Formosa Plastics NX3400, with a molecular weight of 17W and a melt index of 10 g / 10 min (220℃ × 10 kg). The heat resistant agent is N-phenylmaleimide, brand name DENKA MS-CP. The antioxidant is tris(2,4-di-tert-butylphenyl) phosphite, and the lubricant is ethylene bis-stearamide.

[0022] The above components are added to a high-speed mixer and mixed thoroughly. Then, the mixture is placed in a twin-screw extruder and extruded and granulated under a high-shear extrusion process to obtain a high-rigidity SAN blend. The screw speed is controlled at 400-600 rpm and the temperature is controlled at 230-250℃.

[0023] The high-rigidity SAN blend of the present invention has a melt index of 45 g / 10min (220℃×10kg).

[0024] PCR ABS material for preparing ping-pong ball shells By weight, the raw materials were added to a high-speed mixer and thoroughly mixed according to the formulations of Examples 1-4 and Comparative Examples 1-4 in Table 1 below. The mixture was then placed in a twin-screw extruder, with the screw speed controlled at 300-500 rpm and the temperature at 200-230°C. Extrusion granulation was performed to obtain the PCR ABS materials for ping-pong ball shells of Examples 1-4 and Comparative Examples 1-4. Comparative Example 5 is a modified grade ABS virgin material currently used for ping-pong ball shells, with a titanium dioxide content of 1%, and does not require extrusion.

[0025] The specific components in Table 1 are as follows: Low-flow PCR ABS resin: White ABS resin was recovered from the refrigerator liner, with a melt index of 12 g / 10 min (220℃ × 10 kg) and a density of 1.06 g / cm³. 3 The notched impact strength of the cantilever beam is 15 KJ / m. 2 ; High-flow PCR ABS resin: Natural PCR ABS material recycled from air conditioning internal components, with a melt flow index of 23 g / 10 min (220℃ × 10 kg) and a density of 1.05 g / cm³. 3 The notched impact strength of the cantilever beam is 13 KJ / m. 2 ; Large particle size ABS rubber powder: grade is Kumho P / D180 from South Korea, particle size 370nm; Small particle size ABS rubber powder: Grade Kumho 192 powder from South Korea, particle size 100nm; Ordinary SAN resin: grade Chi Mei PN128, melt index 35 g / 10min (220℃×10kg); New ABS material: Grade Chi Mei PA757, melt flow index 19g / 10min (220℃×10kg), density 1.05g / cm³ 3 The notched impact strength of the cantilever beam is 18 KJ / m. 2 ; Antioxidants: Antioxidants formulated with hindered phenolic antioxidants and phosphite antioxidants; Lubricant: Ethylene bis-stearamide, commercially available; Titanium dioxide: rutile type, commercially available.

[0026] The modified ABS material currently used for ping-pong ball shells is provided by Suzhou Juhui Sporting Goods Co., Ltd.

[0027] The products of the examples and comparative examples obtained in Table 1 were dried in a forced-air oven at 80°C for 4 hours, and then injection molded into standard specimens (refer to ISO specimen dimensions) using an injection molding machine. The injection-molded specimens were then placed in an environment of 50±5% relative humidity and 23±2°C for at least 24 hours before performance testing. The performance testing method is as follows: (1) Notched impact strength: Refer to ISO 180-1-2019 standard, type A notch, pendulum energy 5.5J, test temperature 23℃; (2) Melt flow index: According to ISO 1133-1-2011 standard, the test temperature is 220℃ and the load is 10kg; (3) Tensile strength: According to ISO 527-1-2019 standard, the test speed is 50 mm / min; (4) Flexural modulus: According to ISO 178-2019 standard, the test speed is 2mm / min; (5) Rockwell hardness: According to ISO 2039-2:1987(E) standard, the test temperature is 23℃; (6) Color whiteness L value: Refer to GB / T 7921-2008 standard, test light source D65.

[0028] The formulation performance data of the examples and comparative examples are shown in Table 2: The materials from each embodiment and comparative example were injection molded into two hemispheres, and then subjected to processes such as ball bonding, ball expansion and shaping, cooling, washing, and drying to obtain finished ping-pong balls. Performance tests were performed on the finished ping-pong balls, including average weight, average diameter, roundness deviation, and bounce height, referring to ITTF testing methods and standards. In addition, a durability test was conducted on the finished ping-pong balls, specifically by accelerating the ping-pong ball to 20 m / s and continuously impacting a wooden board until the ping-pong ball broke, and the number of impacts was counted. The test results are shown in Table 3 below.

[0029] Examples 1-4 of the present invention all meet the ITTF standards and demonstrate good impact resistance and service life. Compared with Comparative Example 6, Examples 1-4 exhibit higher bounce height, faster ball speed during matches, better ball feel, and are more suitable for high-explosive competitive characteristics.

[0030] As can be seen from Comparative Examples 1 and 2, both insufficient and excessive amounts of small-particle rubber powder in the compound will affect the impact resistance life of the ping-pong ball. When there is too much small-particle rubber powder and too little large-particle rubber powder, the impact strength of the material is low, and the impact resistance life is significantly reduced. When there is too much large-particle rubber powder and too little small-particle rubber powder, the bounce height of the ping-pong ball is closer to the lower limit of the standard, and the impact resistance life is also reduced.

[0031] When ordinary SAN is used, the roundness deviation of the ping-pong ball is slightly increased, indicating that the material undergoes greater thermal deformation during the ping-pong ball swelling and shaping process due to the modification of ordinary SAN resin, resulting in a greater roundness deviation. In addition, the bounce height of the ordinary SAN resin modified is significantly lower than that of Example 2, indicating that the high-rigidity SAN blend improves the rigidity of the material at the molecular level, resulting in strong resistance to deformation during impact, converting more impact energy into gravitational potential energy, and increasing the rebound height.

[0032] Comparative Examples 4 and 5 show that when low-flow PCR ABS material is used alone, the impact strength is low, the roundness deviation is significantly increased, the ball's bounce height is insufficient, and the number of impacts it can withstand is also significantly reduced. Similar problems occur when high-flow PCR ABS material is used alone.

[0033] In summary, Examples 1-4 significantly improved molding stability, impact resistance, and bounce height compared to unmodified PCR ABS material. Compared to currently used modified ABS virgin resin, with similar overall firmness test results, they significantly improved ball rebound height, resulting in faster ball speed, greater explosiveness, and a better user experience.

[0034] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, this specification should be considered illustrative rather than restrictive.

Claims

1. A modified PCR ABS material for ping-pong ball shells, characterized in that, By weight, it includes the following components: low-flow PCR ABS resin: 30-40 parts, high-flow PCR ABS resin: 20-30 parts, large-particle-size ABS rubber powder: 10-15 parts, small-particle-size ABS rubber powder: 3-5 parts, SAN blend: 8-15 parts, virgin ABS material: 0-20 parts. The low-flow PCR ABS resin described above has a melt index of 10–15 g / 10 min (220℃ × 10 kg) and a density of 1.06–1.07 g / cm³. 3 The notched impact strength of the cantilever beam is 13–18 KJ / m. 2 ; The high-flow PCR ABS resin described above has a melt index of 20–25 g / 10 min (220℃ × 10 kg) and a density of 1.04–1.05 g / cm³. 3 The notched impact strength of the cantilever beam is 10–15 KJ / m. 2 ; The particle size of the large-particle-size ABS rubber powder is 350-400 nm; The particle size of the small-particle-size ABS rubber powder is 50-150 nm.

2. The modified PCR ABS material for ping-pong ball shells according to claim 1, characterized in that, The SAN blend comprises the following components by weight: 40-60 parts of high-flow SAN resin, 30-40 parts of high-molecular-weight SAN resin, 10-20 parts of heat resistant agent, 0.1-0.5 parts of antioxidant, and 1-2 parts of lubricant.

3. The modified PCR ABS material for ping-pong ball shells according to claim 2, characterized in that, The high-flow SAN resin has a melt index of 150-250 g / 10 min (220℃×10 kg), the high-molecular-weight SAN resin has a molecular weight of 140,000-200,000, and a melt index of 8-15 g / 10 min (220℃×10 kg); the heat resistant agent is one or more of α-methylstyrene, N-phenylmaleimide, and styrene-maleic anhydride copolymer.

4. The modified PCR ABS material for ping-pong ball shells according to claim 2, characterized in that, The heat-resistant agent is N-phenylmaleimide.

5. The modified PCR ABS material for ping-pong ball shells according to claim 1, characterized in that, Also includes: Antioxidant 0.1-0.5 parts, lubricant 1-2 parts, titanium dioxide 0.5-1 parts.

6. The modified PCR ABS material for ping-pong ball shells according to claim 5, characterized in that, The antioxidant is one or both of hindered phenolic antioxidants and phosphite antioxidants; The titanium dioxide mentioned is anatase or rutile. The lubricant is any one or more of the following: silane polymer, butyl stearate, stearic acid, fatty acid salt, fatty acid amide, ethylene bis-stearamide, and polyethylene wax.

7. The modified PCR ABS material for ping-pong ball shells according to claim 1, characterized in that, By weight, it includes the following components: low-flow PCR ABS resin: 35 parts, high-flow PCR ABS resin: 25 parts, large-particle-size ABS rubber powder: 12 parts, small-particle-size ABS rubber powder: 4 parts, SAN blend: 12 parts, virgin ABS material: 10 parts, antioxidant: 0.2 parts, lubricant: 2 parts, titanium dioxide: 0.5 parts.

8. The modified PCR ABS material for ping-pong ball shells according to claim 1, characterized in that, The low-flow PCRABS resin is a white PCR ABS material recovered from the inner liner of a refrigerator; the high-flow PCR ABS resin is a natural-colored PCR ABS material recovered from the inner components of an air conditioner.

9. The modified PCR ABS material for ping-pong ball shells according to claim 1, characterized in that, The virgin ABS material has a melt flow index of 18–25 g / 10 min (220℃ × 10 kg) and a density of 1.04–1.05 g / cm³. 3 The notched impact strength of the cantilever beam is 17–25 KJ / m. 2 .

10. A method for preparing a modified PCR ABS material for ping-pong ball shells according to any one of claims 1 to 9, characterized in that, The process includes the following steps: melt-blending and extruding the components used to prepare the SAN blend to prepare the SAN blend; and melt-blending and extruding the components used to prepare the modified PCR ABS material to prepare the modified PCR ABS material.

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