Antistatic protective film

Abstract

The invention discloses an antistatic protective film which comprises the following raw materials in parts by mass: 93-115 parts of polyvinyl chloride resin, 21-29 parts of dioctyl phthalate, 0.03-0.05 part of an initiator, 2-3 parts of a stabilizer, 3-9 parts of an antistatic agent, 2-4 parts of an antioxidant and 1-3 parts of a lubricant. Wherein the dioctyl phthalate is used as a plasticizer, so that the plasticity of the material can be improved, the processing performance can be improved, and the prepared protective film can be more attached to the surface of the fitness equipment; wherein the antistatic agent is a zwitterionic antistatic agent, and compared with a single ionic antistatic agent, the antistatic agent has better antistatic performance, good stability and antibacterial property; in conclusion, the prepared antistatic protective film solves the problem that the antistatic property and the antibacterial property of a traditional PVC protective film cannot be considered at the same time, is suitable for high-frequency contact scenes such as a touch screen and a biological recognition mirror, and has important application value in the technical field of intelligent equipment in a gymnasium.

Description

Technical Field

[0001] The present invention belongs to the technical field of protective films, and in particular relates to an antistatic protective film. Background Art

[0002] With increasing awareness of health and obesity, gyms have become a vital venue for people pursuing a healthy lifestyle. Modern gyms are also becoming increasingly intelligent, with smart fitness equipment such as interactive strength trainers, touch-sensitive cardio equipment, and biometric mirrors becoming standard features. These devices frequently come into contact with sweat and skin, posing challenges such as static interference and touch failure, and becoming potential vectors for the spread of bacteria and viruses.

[0003] PVC protective film has been widely used in recent years to protect the touchscreens of smart fitness equipment due to its low price and excellent chemical resistance. However, traditional PVC protective film has significant shortcomings in this specialized application scenario: Conventional PVC protective film is ineffective in inhibiting the growth of microorganisms on the equipment surface. Furthermore, exercisers sweat profusely during exercise, and contact between sweat and sebum and the equipment surface creates ideal conditions for bacterial growth. Statistics show that the bacterial colony count on the touchscreen surface of smart gym equipment can reach 1200-1500 CFU per square centimeter, with Staphylococcus aureus and Escherichia coli detected in over 65% of cases.

[0004] From an anti-static perspective, since PVC is a typical polymer insulating material, it is highly susceptible to static electricity in gym environments, where people frequently exercise and equipment rubs against each other. This static electricity can absorb impurities such as dust and hair from the air, staining the surface of fitness equipment and affecting its appearance and lifespan. Furthermore, static electricity can interfere with electronic equipment in the gym, with the false alarm rate for touch controls due to static accumulation reaching as high as 15%-20%. For gym goers, touching equipment with static electricity can cause discomfort and even psychological resistance, diminishing the fitness experience.

[0005] Currently, common antistatic films on the market are unable to inhibit the growth of microorganisms on the surface of equipment, while commercially available antibacterial films often ignore the need for electrostatic protection. Therefore, there is an urgent need to develop a PVC protective film with both antibacterial and antistatic properties to meet the application of PVC protective films in the field of smart fitness equipment. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a PVC protective film with both antibacterial and antistatic properties.

[0007] The purpose of the present invention can be achieved through the following technical solutions: An antistatic protective film is prepared by the following steps: Step A1: adding polyvinyl chloride resin, dioctyl phthalate, an initiator, a stabilizer, an antistatic agent, an antioxidant, and a lubricant into a high-speed mixer and mixing the components to fully disperse and uniformly mix them to obtain a mixture; Step A2: transferring the mixed material to a twin-screw extruder, fully plasticizing and melting the mixed material in the extruder, and extruding the mixed material through a T-die, cooling and shaping the mixed material through a cooling roller, and finally obtaining an antistatic protective film after pulling, slitting and winding.

[0008] As a further technical solution, the raw materials are calculated in parts by mass as follows: 93-115 parts of polyvinyl chloride resin, 21-29 parts of dioctyl phthalate, 0.03-0.05 parts of initiator, 2-3 parts of stabilizer, 3-9 parts of antistatic agent, 2-4 parts of antioxidant and 1-3 parts of lubricant.

[0009] As a further technical solution, the initiator is a peroxide initiator.

[0010] As a further technical solution, the stabilizer is a calcium zinc stabilizer.

[0011] As a further technical solution, the antioxidant is one of triphenyl phosphite and trinonylphenyl phosphite.

[0012] As a further technical solution, the lubricant is one of erucamide, oleamide and stearamide.

[0013] As a further technical solution, during the mixing process, the rotation speed of the high-speed mixer is 800-1200 r / min, and the mixing time is 15-20 min.

[0014] As a further technical solution, the temperature of each section of the twin-screw extruder is: 160-170°C in the feeding section, 170-180°C in the compression section, 180-190°C in the homogenizing section, and 175-185°C in the die head.

[0015] As a further technical solution, the antistatic agent is prepared by the following steps: Step B1: In a three-necked round-bottom flask, N,N-dimethylformamide, sodium o-formylbenzenesulfonate, and 4-aminopyridine were added in sequence, and after mechanical stirring and mixing, p-toluenesulfonic acid was added as a catalyst. The device was placed in a water bath at 50-55°C, and the reaction was kept warm for 4-5 hours under stirring. After the reaction was completed, the product was post-processed to obtain a preliminary product. Step B2, in a three-port round-bottom flask, N,N-dimethylformamide and the primary product were sequentially added, and after mechanical stirring and mixing, allyl chloride was slowly added into the flask at 0-5 DEG C in an ice bath using a constant pressure dropping funnel, after the addition was completed, a condenser was installed, and the temperature was increased to 60-80 DEG C, and the reaction was carried out for 6-7 h, after the reaction was completed, the product was obtained after post-treatment.

[0016] As a further technical solution, the ratio of the amount of N,N-dimethylformamide, sodium o-formylbenzenesulfonate, 4-aminopyridine and p-toluenesulfonic acid in step B1 is 150 mL:20.8 g:9.4 g:1.7 g.

[0017] As a further technical solution, the ratio of the amount of N,N-dimethylformamide, the primary product and allyl chloride in step B2 is 100 mL:28.4 g:7.6 g.

[0018] The reaction formula of the preparation process of the antistatic agent is as follows: In the preparation process of the antistatic agent, p-toluenesulfonic acid is used as a Lewis acid catalyst in step B1 to enhance the electrophilicity of the aldehyde and accelerate the nucleophilic attack on the 4-aminopyridine to obtain the primary product; and then allyl chloride is used to react with the primary product to obtain the target product, the antistatic agent, in step B2.

[0019] The prepared antistatic agent is a zwitterionic compound because it contains quaternary ammonium cations and sulfonate anions, and thus exhibits unique antistatic properties. Compared with single-ion antistatic agents, the zwitterionic antistatic agent has stronger ionic conductivity, and the internal salt structure (self-balancing positive and negative charges) of the zwitterion reduces the molecular migration tendency, and the stability in the PVC matrix is significantly higher than that of single-ion antistatic agents. In addition, the quaternary ammonium cation has excellent antibacterial properties and can synergize with the Schiff base group in the antistatic agent to significantly improve the antibacterial properties of the PVC matrix. Finally, the introduction of an unsaturated double bond at one end of the antistatic agent can cross-link with the PVC matrix under the action of an initiator, further improving the anti-migration and durability of the small-molecule antistatic agent.

[0020] Advantages of the application: Advantage 1: The addition of dioctyl phthalate as a plasticizer can reduce the melting temperature and melt viscosity of the PVC resin, increase the plasticity of the material, improve the processing performance, and make the prepared protective film more fit the surface of the fitness equipment without affecting the antistatic properties. Advantage 2: The zwitterionic antistatic agent prepared in the application has better antistatic properties and stability than single-ion antistatic agents, and has antibacterial properties. In summary, the antistatic protective film prepared by the present invention solves the problem that traditional PVC protective films cannot achieve both antistatic and antibacterial properties. It is suitable for high-frequency contact scenarios such as touch screens and biometric mirrors, and has important application value in the field of intelligent equipment technology in gyms. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] Example 1 Preparation of antistatic agent: Step B1: In a three-necked round-bottom flask, 150 mL of N,N-dimethylformamide, 20.8 g of sodium o-formylbenzenesulfonate, and 9.4 g of 4-aminopyridine were added in sequence. After mechanical stirring to mix evenly, 1.7 g of p-toluenesulfonic acid was added as a catalyst. The device was placed in a 50°C water bath and stirred for 4 hours. After the reaction was completed, the product was filtered, rotary evaporated, and purified by silica gel column chromatography (eluent: CH2Cl2 / MeOH=5:1) to obtain a preliminary product. Step B2: In a three-necked round-bottom flask, 100 mL of N, N-dimethylformamide and 28.4 g of the preliminary product were added in sequence. After mechanical stirring to mix evenly, 7.6 g of allyl chloride was slowly added dropwise to the flask using a constant pressure dropping funnel under ice bath conditions at 0 ° C. After the addition was completed, a condenser was installed, the temperature was raised to 60 ° C, and the reaction was carried out for 6 hours. After the reaction was completed, the mixture was filtered, rotary evaporated, and purified by silica gel column chromatography (eluent: CH2Cl2 / MeOH=5:2) to obtain an antistatic agent.

[0023] Example 2 Preparation of antistatic agent: Step B1: In a three-necked round-bottom flask, 150 mL of N,N-dimethylformamide, 20.8 g of sodium o-formylbenzenesulfonate, and 9.4 g of 4-aminopyridine were added in sequence. After mechanical stirring to mix evenly, 1.7 g of p-toluenesulfonic acid was added as a catalyst. The device was placed in a 55°C water bath and stirred for 5 hours. After the reaction was completed, the product was filtered, rotary evaporated, and purified by silica gel column chromatography (eluent: CH2Cl2 / MeOH=5:1) to obtain a preliminary product. Step B2: In a three-necked round-bottom flask, 100 mL of N, N-dimethylformamide and 28.4 g of the preliminary product were added in sequence. After mechanical stirring to mix evenly, 7.6 g of allyl chloride was slowly added dropwise to the flask using a constant pressure dropping funnel under an ice bath at 5 ° C. After the addition was completed, a condenser was installed, the temperature was raised to 80 ° C., and the reaction was carried out for 7 hours. After the reaction was completed, the mixture was filtered, rotary evaporated, and purified by silica gel column chromatography (eluent: CH2Cl2 / MeOH=5:2) to obtain an antistatic agent.

[0024] Example 3 An antistatic protective film is prepared by the following steps: Step A1: 93 g of polyvinyl chloride resin, 21 g of dioctyl phthalate, 0.03 g of dilauroyl peroxide, 2 g of calcium zinc stabilizer (CZX-681), 3 g of the antistatic agent prepared in Example 1, 2 g of triphenyl phosphite, and 1 g of erucamide were added to a high-speed mixer and mixed at a speed of 800 r / min for 15 min to fully disperse and uniformly mix the components to obtain a mixture; Step A2: The mixed material is transferred to a twin-screw extruder (feeding section 160-170°C, compression section 170-180°C, homogenization section 180-190°C, die head temperature 175-185°C), the mixed material is fully plasticized and melted in the extruder, extruded through a T-die, cooled and shaped by a cooling roller, and then pulled, slit, and wound to finally obtain an antistatic protective film.

[0025] Example 4 An antistatic protective film is prepared by the following steps: Step A1: 104 g of polyvinyl chloride resin, 25 g of dioctyl phthalate, 0.04 g of dicyclohexyl peroxydicarbonate, 2.5 g of calcium zinc stabilizer (CZX-681), 6 g of the antistatic agent prepared in Example 2, 3 g of trisnonylphenyl phosphite, and 2 g of oleamide were added to a high-speed mixer and mixed at a speed of 1000 r / min for 20 min to fully disperse and uniformly mix the components to obtain a mixture; Step A2: The mixed material is transferred to a twin-screw extruder (feeding section 160-170°C, compression section 170-180°C, homogenization section 180-190°C, die head temperature 175-185°C), the mixed material is fully plasticized and melted in the extruder, extruded through a T-die, cooled and shaped by a cooling roller, and then pulled, slit, and wound to finally obtain an antistatic protective film.

[0026] Example 5 An antistatic protective film is prepared by the following steps: Step A1: 115 g of polyvinyl chloride resin, 29 g of dioctyl phthalate, 0.05 g of dicyclohexyl peroxydicarbonate, 3 g of calcium zinc stabilizer (CZX-681), 9 g of the antistatic agent prepared in Example 2, 4 g of trisnonylphenyl phosphite, and 3 g of stearamide were added to a high-speed mixer and mixed at a speed of 1200 r / min for 20 min to fully disperse and uniformly mix the components to obtain a mixture; Step A2: The mixed material is transferred to a twin-screw extruder (feeding section 160-170°C, compression section 170-180°C, homogenization section 180-190°C, die head temperature 175-185°C), the mixed material is fully plasticized and melted in the extruder, extruded through a T-die, cooled and shaped by a cooling roller, and then pulled, slit, and wound to finally obtain an antistatic protective film.

[0027] Comparative Example 1 9 g of dimethyl distearyl ammonium chloride (single ion antistatic agent) was used to replace the antistatic agent in Example 5, and the remaining steps were the same as in Example 5 to prepare a protective film.

[0028] Comparative Example 2 Use unmodified ordinary PVC protective film.

[0029] In order to verify the effect of the solution of the present invention on the performance of the protective film, the protective films obtained in Examples 3, 4, 5 and the comparative example were tested. The test method is as follows. The test results are shown in Table 1. Cut the protective film into 10×10 cm samples and measure the surface resistance using a high resistance meter; The protective film was applied to the touch screen of a smart device and wiped 100 times a day (with alcohol pads) for one week. Then, a 10×10 cm sample was cut and the surface resistance was measured with a high resistance meter to determine the antistatic durability of Examples 3, 4, 5, and Comparative Example 1. The national standard GB / T 31402-2015 "Test method for antibacterial properties of plastic surfaces" was used, and the film method was used to detect the inhibitory effect on E. coli; Table 1 The test results shown in Table 1 show that the antistatic protective film prepared in the embodiment of the present invention has higher surface resistance and antibacterial rate than the comparative example due to the addition of the antistatic agent. Therefore, it has important application value in the field of intelligent gym equipment technology.

[0030] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0031] The above contents are merely examples and explanations of the present invention. Any modifications or additions made by those skilled in the art to the described specific embodiments, or replacements made in a similar manner, shall fall within the scope of protection of the present invention.

Claims

1. An antistatic protective film, characterized in that: The invention comprises the following raw materials in parts by weight: 93-115 parts of polyvinyl chloride resin, 21-29 parts of dioctyl phthalate, 0.03-0.05 parts of initiator, 2-3 parts of stabilizer, 3-9 parts of antistatic agent, 2-4 parts of antioxidant and 1-3 parts of lubricant.

2. The antistatic protective film according to claim 1, characterized in that: The antistatic agent is prepared by the following steps: Step B1: In a flask, add N,N-dimethylformamide, sodium o-formylbenzenesulfonate and 4-aminopyridine in sequence, stir and mix, then add p-toluenesulfonic acid, and react at 50-55° C. for 4-5 hours. The reaction is completed to obtain a preliminary product; Step B2: In a flask, add N,N-dimethylformamide and the preliminary product in sequence, stir and mix evenly, then add allyl chloride dropwise into the flask at 0-5°C. After the addition is complete, react at 60-80°C for 6-7h. After the reaction is complete, an antistatic agent is obtained.

3. The antistatic protective film according to claim 2, characterized in that: In step B1, the ratio of N,N-dimethylformamide, sodium o-formylbenzenesulfonate, 4-aminopyridine, and p-toluenesulfonic acid is 150 mL: 20.8 g: 9.4 g: 1.7 g.

4. The antistatic protective film according to claim 2, characterized in that: In step B2, the ratio of N,N-dimethylformamide, preliminary product, and allyl chloride is 100 mL: 28.4 g: 7.6 g.

5. The antistatic protective film according to claim 1, characterized in that: The initiator is a peroxide initiator.

6. The antistatic protective film according to claim 1, characterized in that: The stabilizer is a calcium zinc stabilizer.

7. The antistatic protective film according to claim 1, characterized in that: The antioxidant is one of triphenyl phosphite and trinonylphenyl phosphite.

8. The antistatic protective film according to claim 1, characterized in that: The lubricant is one of erucamide, oleamide and stearamide.

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