An antistatic plasticized transparent elastic film of polyvinyl chloride and its preparation method

Abstract

This invention discloses an antistatic plasticized transparent elastic PVC film, which features high elasticity, high visible light transmittance, low surface resistivity, and stable antistatic effect during long-term use. In particular, it utilizes a plasticizer with dual antistatic and plasticizing functions, overcoming the limitations of current antistatic plasticized PVC transparent films that only offer low surface resistivity due to the addition of surfactant-type antistatic agents. This satisfies the specific needs of the high-end market. The antistatic plasticized transparent elastic PVC film of this invention is made from the following raw materials in the indicated weight ratios: 70-85 parts PVC resin, 15-30 parts nitrile rubber, 45-60 parts antistatic plasticizer, 3-10 parts non-antistatic plasticizer, 0.3-0.6 parts liquid organotin heat stabilizer, 0.8-1.5 parts liquid calcium-zinc heat stabilizer, 3-5 parts surface-modified porous silica, and 0.5-0.6 parts lubricant.

Description

Technical Field

[0001] This invention relates to a functional polyvinyl chloride film and its preparation method, and more specifically to an antistatic plasticized transparent elastic polyvinyl chloride film and its preparation method. Background Technology

[0002] The amorphous structure of polyvinyl chloride (PVC) resin gives it good visible light transmittance, making it an ideal material for preparing transparent films. Commercially available PVC resin is mainly produced using two polymerization methods: suspension polymerization and emulsion polymerization. The resulting resins are referred to as suspension PVC resin and emulsion PVC resin, respectively. Suspension PVC resin, because no emulsifier is added during polymerization, exhibits relatively high purity, excellent visible light transmittance, good electrical insulation properties, low haze, and good mechanical strength, making it the preferred material for producing transparent PVC plastic products and insulating wires and cables. Emulsion PVC, on the other hand, incorporates emulsifiers during polymerization, resulting in resins with small particle size and excellent paste-forming properties when mixed with plasticizers. It is particularly suitable for dip coating, coating, and scraping processes to produce plasticized PVC plastic products such as gloves, artificial leather, and flooring. The emulsion-process PVC resin contains emulsifiers, resulting in poor transparency and making it unsuitable for preparing plasticized transparent films. Furthermore, the presence of emulsifiers affects the electrical insulation properties of PVC resin. From this perspective, emulsion-process PVC resin is not suitable for preparing insulating films for wires and cables, electrical tapes, and other products requiring good electrical insulation. Instead, it is suitable for preparing PVC products with antistatic or conductive requirements. In contrast, suspension-process PVC resin offers high transparency and high electrical insulation. If choosing PVC resin to prepare transparent PVC films, only suspension-process PVC resin can potentially meet the requirements. However, choosing suspension-process PVC resin is disadvantageous in formulations requiring antistatic or conductive plasticized transparent PVC films.

[0003] There are many types of plasticizers that can be used in plasticized PVC products. Based on their chemical structure, they can generally be divided into the following categories: 1. Phthalate plasticizers: such as dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), di(2-propylheptyl) phthalate (DPHP), etc. Among these, DBP and DEHP are restricted because they are harmful to the environment and human health and do not meet the requirements of the EU RoHS directive. 2. Terephthalate plasticizers: such as dioctyl terephthalate (DOTP), di(2-ethylhexyl) terephthalate, etc. 3. Aliphatic diester plasticizers: such as dioctyl adipate (DOA), dioctyl sebacate (DOS), and diisononyl adipate (DINA), etc. 4. Phosphate ester plasticizers: such as tricresyl phosphate (TCP), triphenyl phosphate (TPP), and diphenyl isooctyl phosphate (DPOP). 5. Compound plasticizers: such as epoxidized oil and epoxidized soybean oil (ESBO). 6. Polymer plasticizers: polyester plasticizers (PPA), powdered nitrile butadiene rubber (PNBR), nitrile butadiene rubber (NBR), chlorinated polyethylene (CPE), etc. 7. Other plasticizers: such as citrate plasticizers, such as tributyl citrate (TBC) and acetylated tributyl citrate (ATBC); polymethyl phthalate plasticizers, such as trioctyl trimellitate (TOTM); chlorinated plasticizers, such as chlorinated paraffin and chlorinated palm oil. Of the above plasticizers, except for some polymers such as emulsion-polymerized nitrile butadiene rubber and chlorinated polyethylene, which may affect the transparency of PVC products, most plasticizers, especially small-molecule plasticizers, can be mixed with suspension-polymerized PVC to prepare plasticized transparent PVC products. Meanwhile, the plasticized transparent PVC products obtained by mixing and processing these plasticizers with suspension PVC resin all exhibit good electrical insulation properties, namely, high surface resistivity (surface resistivity coefficient), volume resistivity (volume resistivity coefficient), and dielectric strength, which can meet the requirements for insulating plastic products in many medium and low voltage applications. For example, by combining suspension PVC resin with plasticizers such as DEHP, DOTP, TOTM, DINP, DIDP, and PPA, it is possible to produce products that meet the requirements of standard "GB / T 8815-2008 Soft Polyvinyl Chloride Plastics for Wires and Cables," such as 70℃ insulated cable materials and 70℃ sheathed cable materials, with volume resistivity greater than 1×10⁻⁶. 12 Ω·m and 1×10 11 Ω·m.

[0004] In existing technologies, the preparation of plasticized PVC products with antistatic or conductive properties typically employs the following methods: 1. Adding an antistatic agent to the plasticized PVC formulation; 2. Adding conductive metal powder, such as silver, to the plasticized PVC formulation; 3. Adding conductive fibers, such as carbon fiber, carbon nanotubes, copper fiber, etc., to the plasticized PVC formulation; 4. Adding conductive carbon materials, such as graphite, graphene, conductive carbon black, etc., to the plasticized PVC formulation. Of these methods, only the method of adding an antistatic agent to the plasticized PVC formulation can potentially produce a transparent antistatic film. Commonly used antistatic agents are compounds with surfactant characteristics, mainly including anionic, cationic, and nonionic antistatic agents. If the plasticized PVC formulation contains a sufficient concentration of antistatic agent, during the later stages of molding, the antistatic agent molecules migrate to the plastic surface or interface and form an oriented arrangement. The lipophilic groups (non-polar portions) of the antistatic molecules, which have surfactant characteristics, are arranged in the plasticized PVC matrix, while the hydrophilic groups (polar portions) are arranged on the air-facing side of the PVC plastic product surface, forming a monomolecular conductive layer. Plasticized PVC films prepared using this method without fillers have good transparency and antistatic properties. However, the antistatic effect of the film increases with time in the initial stage of use, but weakens after prolonged use. This is because during processing, the antistatic agent is uniformly dispersed in the PVC matrix resin. In the freshly processed film, the antistatic agent does not have enough time to accumulate on the surface, resulting in low surface resistivity and poor antistatic effect. As the product's storage or usage time increases, the antistatic agent accumulates on the surface, forming a higher concentration and exhibiting a better antistatic effect. During prolonged use, the concentration of small-molecule antistatic agents on the surface of PVC films decreases due to factors such as evaporation, washing, or friction, leading to a decline in the film's antistatic effect. The amphiphilic molecular structure and antistatic mechanism of these antistatic agents result in the following drawbacks: First, these antistatic agents work by absorbing ambient moisture to reduce the surface resistivity of the material, making them highly dependent on ambient humidity. High humidity results in strong water absorption and a significant antistatic effect; conversely, low humidity weakens their absorption and reduces their effectiveness. Second, as these antistatic agents continuously accumulate on the surface to reduce resistivity, the concentration of antistatic agents within the film gradually decreases, leading to an increase in volume resistivity. This is unsuitable for applications requiring both low surface and low volume resistivity.

[0005] In summary, since only commercially available suspension PVC resin can be used for plasticizing transparent PVC products, and given the good electrical insulation properties of suspension PVC resin, its combination with commonly used plasticizers can only produce plasticized transparent PVC insulating films with high surface resistivity, volume resistivity, and dielectric strength. While commercially available emulsion PVC combined with commonly used plasticizers is indeed suitable for producing plasticized antistatic or conductive PVC films with lower surface resistivity, volume resistivity, and dielectric strength, these films lose transparency and cannot meet the requirements of specific applications. Therefore, existing methods for preparing antistatic plasticized transparent elastic PVC films use suspension PVC resin, supplemented with non-antistatic plasticizers, surfactant-type antistatic agents, special stabilizers, and small amounts of other functional additives. Although commercially available antistatic plasticized transparent PVC films can meet some application requirements, existing technologies have not yet adequately addressed the stability of the long-term antistatic effect of plasticized transparent PVC films or the preparation of functional films that simultaneously meet the requirements of low surface resistivity and low volume resistivity for various applications. Therefore, it is necessary to develop an antistatic plasticized PVC transparent elastic film and its preparation method to address the shortcomings of existing industries. This film should be a transparent plasticized PVC functional film with long-term stable antistatic effect, low surface resistivity and low volume resistivity, as well as high elasticity, water resistance or water extraction resistance, to meet the new technical needs of industries such as electronics, electrical appliances, automobiles, construction, and packaging. Summary of the Invention

[0006] The purpose of this invention is to address the problems and shortcomings of existing technologies and provide an antistatic plasticized PVC transparent elastic film. This functional transparent film has the characteristics of high elasticity, high visible light transmittance, low surface resistivity, low volume resistivity, stable antistatic effect during long-term use, and excellent comprehensive mechanical properties. In particular, it uses plasticizers with dual functions of antistatic and plasticizing, such as dibutyl diglyceride adipate (DBEEA) and dibutyl diglyceride glutarate (DBEEG), which makes up for the fact that current antistatic plasticized PVC transparent film products only have the advantage of low surface resistivity due to the addition of surfactant-type antistatic agents, thus meeting the special needs of the high-end market.

[0007] The present invention also provides a method for preparing the antistatic plasticized polyvinyl chloride transparent elastic film, which is simple, easy to implement, and low in cost.

[0008] This invention is achieved through the following technical solution:

[0009] The antistatic plasticized polyvinyl chloride transparent elastic film of the present invention is made from the following raw materials in the indicated mass ratios:

[0010]

[0011]

[0012] The antistatic plasticized transparent elastic polyvinyl chloride film of the present invention is further described in that the polyvinyl chloride resin is a linear polyvinyl chloride resin or a combination thereof synthesized by suspension polymerization process with an average degree of polymerization between 1300 and 1500; the resin with a degree of polymerization between 1300 and 1500 is selected because it has rubber properties that can improve elasticity and maintain good flowability.

[0013] A further technical solution of the antistatic plasticized transparent elastic polyvinyl chloride film of the present invention can be that the nitrile rubber is a binary random copolymer obtained by solution polymerization of butadiene and acrylonitrile as monomers, wherein the mass percentage of acrylonitrile is 26-41%. Rubber produced by solution polymerization has better transparency than rubber produced by emulsion polymerization; in addition, a medium-to-high acrylonitrile content is also considered to help improve the polarity of the rubber and reduce surface resistance. A further technical solution is that the nitrile rubber is preferably one or a combination of pre-crosslinked powdered nitrile rubber, uncrosslinked block nitrile rubber, or the pre-crosslinked powdered nitrile rubber having a crosslinking degree of 40-55% or a combination thereof; the uncrosslinked block nitrile rubber having a medium-to-low Mooney viscosity (ML(1+4) 100°C) of 30-50 or a combination thereof. Pre-crosslinked powdered nitrile rubber can improve elasticity and reduce permanent deformation, more effectively preventing the antistatic plasticizer from being extracted by water; the uncrosslinked block nitrile rubber, due to its large molecular weight, helps to improve tensile strength, and the low Mooney viscosity can avoid poor flowability.

[0014] A further technical solution of the antistatic plasticized polyvinyl chloride transparent elastic film of the present invention may be that the antistatic plasticizer is one or a combination of dibutyl diglyceride adipate and dibutyl diglyceride glutarate.

[0015] A further technical solution for the antistatic plasticized transparent elastic polyvinyl chloride film of the present invention may be that the non-antistatic plasticizer is a polyester plasticizer (PPA), trioctyl trimellitate (TOTM), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), or di(2-propylheptyl phthalate) (DPHP). The addition of 3 to 10 parts of the non-antistatic plasticizer does not affect the surface resistance and transparency of the film, but can appropriately improve the pull-out resistance of the antistatic plasticizer, especially with relatively high molecular weight polyester plasticizers, and can further improve the elasticity of the film. A further technical solution is that the non-antistatic plasticizer is preferably a relatively high molecular weight polyester plasticizer, namely polypropylene adipate with a number average molecular weight of 3000.

[0016] A further technical solution to the antistatic plasticized polyvinyl chloride transparent elastic film of the present invention may be that the surface-modified porous silica is produced by a gas-phase method with a purity greater than 99.8% and a specific surface area of ​​350-410 m². 2 / g, original particle size 7-10nm, oleophilic and hydrophobic silica. The high specific surface area and oleophilic pores can absorb the precipitated plasticizers, while the nano- and hydrophobic characteristics can improve the surface water contact angle, effectively preventing water from contacting the film.

[0017] A further technical solution to the antistatic plasticized transparent elastic polyvinyl chloride film of the present invention may be that the lubricant is a non-oxidized low-density polyethylene wax with a melting point of 95-105°C and a number-average molecular weight of 2000-3000. When the plasticizer content is high, the film processing temperature is relatively low. Selecting a low-melting-point polyethylene wax can ensure that the film migrates quickly to the surface in the later stages of processing, improving processing speed and efficiency. Simultaneously, the high hydrophobicity of the non-oxidized polyethylene wax synergistically reduces surface energy and increases the water contact angle of the film.

[0018] The method for preparing the antistatic plasticized polyvinyl chloride transparent elastic film of the present invention includes the following steps:

[0019] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 300-400 rpm for 1-2 minutes. Add half of the antistatic plasticizer and switch to high-speed mixing mode to mix evenly, controlling the speed at 650-900 rpm for 3-5 minutes. When the temperature reaches 50-60℃, continue adding the remaining antistatic and non-antistatic plasticizers. Continue mixing until all plasticizers are completely absorbed by the resin. Add surface-modified porous silica and lubricant, and continue mixing until the material temperature reaches 80-90℃. Observe the dryness of the powder; the optimal state is a dry consistency where it does not clump when squeezed by hand. Stop mixing when this is achieved. Finally, discharge the well-mixed material into an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 60-100 rpm. If using pre-crosslinked nitrile rubber powder, add it when the material cools to 40℃, and continue mixing until it reaches 40±5℃ before discharging into a storage silo to obtain the well-mixed plasticized PVC powder material. Uncrosslinked blocky nitrile rubber...

[0020] Plasticized PVC and Filtration: 1) Control the temperature of the internal mixer to 140-150℃. If using uncrosslinked block nitrile rubber, add it at this time and mix it with the prepared plasticized PVC powder in the internal mixer for 3-5 minutes; 2) The internally mixed material is then conveyed to the open mill for further plasticization. Control the open mill roller speed to 40-60 r / min and the open mill temperature to 165-175℃; 3) Because the elastic film contains a high amount of plasticizer and nitrile rubber, the filter screen of the filter uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 170-180℃, and the machine body return water temperature is 20-40℃ to prevent the material temperature from being too high, the melt strength from being too high, and the frictional heating from being too high, which could lead to early degradation of PVC.

[0021] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized polyvinyl chloride transparent elastic film is obtained. The film forming parameters for the four-roll calender are as follows: Roll #1 temperature control 180-190℃, speed 5-15m / min; Roll #2 temperature control 180-195℃, speed 10-30m / min; Roll #3 temperature control 185-195℃, speed 20-40m / min; Roll #4 temperature control 140-160℃, speed 25-40m / min. The drawing and embossing parameters are as follows: One first-stage drawing roller, temperature control 150-160℃, speed 30-50m / min; Two second-stage drawing rollers, temperature control 150-160℃, speed 30-50m / min; Two third-stage drawing rollers, 150-160℃, speed 40-50m / min. The cooling and winding parameters are as follows: Cooling roller temperature control 40-60℃, speed 40-50m / min; winding speed 45-55m / min.

[0022] In this invention, the surface resistivity and volume resistivity in air are tested according to standard GB / T 8815-2008. A ZC 36 high-resistivity meter (Shanghai Sixth Electronic Instrument Manufacturing Plant) is used to test the volume and surface resistivity of the plasticized PVC film placed in air. Resistivity is an important standard for measuring the electrical conductivity of a material. The following is the formula for calculating resistivity:

[0023]

[0024]

[0025] Where ρ v and ρ s These are volume and surface resistivity, respectively; R v and R s These are volume and surface resistivity, respectively; A et refers to the area of ​​the bottom electrode; t refers to the thickness of the plasticized PVC film; d1 and d2 are the diameters of the measuring electrode and the protective electrode, respectively.

[0026] Surface resistivity and volume resistivity tests after water extraction: These were conducted according to standard GB / T 8815-2008, using a ZC36 high-resistivity meter (Shanghai Sixth Electronic Instrument Manufacturing Plant) to test the volume and surface resistivity of the soaked plasticized PVC film. Additionally, the film surface must be dried before testing; other testing methods are the same as above.

[0027] Water extraction resistance and weight loss test: The film was weighed before and after immersion using an electronic balance. The weight loss rate of the film after each immersion was calculated. The formula for the film weight loss rate is as follows:

[0028]

[0029] Where ΔW is the weight loss rate; W0 and W1 are the masses of the film before and after immersion, respectively.

[0030] Transmittance and haze testing: Performed according to ASTM D 1003 standard, with film dimensions of 25mm × 25mm × 0.25mm. Transmittance and haze of the film were measured using a WGW photoelectric haze meter from Shanghai Instrument & Electronics Physical Optics Instrument Co., Ltd. Haze is expressed as the percentage of scattered light flux to transmitted light flux, while transmittance is the percentage of light flux transmitted through the sample to its incident light flux. Generally, higher transmittance and lower haze indicate better optical performance of the film.

[0031] Tensile permanent deformation test: The tensile permanent deformation of the film was tested using a universal testing machine (SANS Testing Machines Ltd.) according to standard ISO 527–3:1995. Before the test, the sample strips were placed at 23±2℃ for 48 hours. The tensile speed was 50 mm / min; the sample was a dumbbell-shaped strip with a thickness of 1 mm, and each sample was measured three times and the average value was taken.

[0032] Compression set test: conducted according to standard GB / T 7759.1-2015. The sample was cylindrical, with a diameter of 29.5 mm and a height of 12.5 mm. Test conditions: 70℃ × 22 h, compression ratio 25 ± 2%.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] This invention overcomes the following shortcomings in the existing technology for preparing antistatic plasticized transparent PVC films by specifically selecting materials, designing formulations, and designing processes, and making creative improvements. Specific effects are as follows: ① Films prepared by combining linear PVC resin synthesized using suspension polymerization with an average degree of polymerization between 1300 and 1500 with plasticizers exhibit better transparency while balancing elasticity and processability. Selecting PVC resins with an average degree of polymerization below 1300, such as PVC resin with an average degree of polymerization of 1000, although slightly improving processing flow, significantly increases the permanent deformation characteristic of the film's elasticity and decreases elasticity. The reason for not selecting PVC resins with an average degree of polymerization above 1500 (or even higher, above 2000), or partially chemically cross-linked PVC resins to improve film elasticity, is that they affect the calendering and processing performance of the film, especially when nitrile rubber is added to the formulation, where processing flow performance becomes even more important. ② Compared to the insulating characteristics of traditional plasticizers, antistatic plasticizers DBEEA and DBEEG, when combined with suspension PVC resin, produce plasticized PVC films with better transparency, lower haze, and lower surface and volume resistivity, resulting in excellent antistatic properties. Therefore, when using DBEEA and DBEEG to prepare antistatic transparent PVC elastic films, due to their dual plasticizing and antistatic functions, it is unnecessary to add an antistatic agent as with other plasticizers such as DEHP, DOTP, TOTM, DINP, DIDP, and PPA. ③ Based on the molecular structures of antistatic plasticizers DBEEA and DBEEG, the solubility parameters of antistatic plasticizer DBEEA were calculated using both Small and Fedors estimation methods: 17.94 and 19.03 (J / cm³), respectively. 3 ) 1 / 2 The solubility parameters of the antistatic plasticizer DBEEG were 17.91 and 19.00 (J / cm³), respectively. 3 ) 1 / 2 The solubility parameter of PVC resin is 19.37 (J / cm³). 3 ) 1 / 2Very close. Because plasticizers DBEEA and DBEEG have excellent compatibility with PVC, compared to antistatic agents, PVC films containing these two plasticizers are less prone to surface leaching during long-term use in air, thus exhibiting a long-term antistatic effect. This overcomes the phenomenon where antistatic agents migrate and volatilize to the surface during long-term use, leading to a gradual decrease in antistatic effect with increasing usage time. ④ Although plasticizers DBEEA and DBEEG have excellent compatibility with PVC, and their antistatic effect remains unchanged during long-term use in air, studies have found that after immersing the antistatic plasticized PVC transparent elastic film prepared with antistatic plasticizers in water for 8 weeks, the extraction rate of plasticizer DBEEA reached as high as 19.61%. Because most of the antistatic plasticizer was extracted by water, the antistatic performance of the film decreased sharply, and the film returned to a highly insulating state. To address this, we creatively employed nitrile rubber as a water-resistant modifier for plasticizers DBEEA and DBEEG, effectively solving the problem of antistatic plasticized PVC transparent elastic film in water environments, high-humidity areas, or applications requiring water cleaning, such as the electronics industry, ensuring the stability of the antistatic effect during long-term use. ⑤ The nitrile rubber with an acrylonitrile content of 26-41% obtained by solution polymerization is chosen because, compared to rubber produced by emulsion polymerization, rubber obtained by solution polymerization has better visible light transmittance. The prepared films all have visible light transmittance above 85%, while the corresponding haze is only 7-9%. Furthermore, the medium-high acrylonitrile content of 26-41% helps to improve the rubber's polarity and reduce surface resistivity and volume resistivity. Based on the Small estimation method, the solubility parameter of the nitrile rubber selected in this invention is calculated to be 19.83-21.09 (J / cm³). 3 ) 1 / 2 The solubility parameter is greater than that of PVC resin, which is 19.37 (J / cm³). 3 ) 1 / 2This indicates that the addition of nitrile rubber with a medium to high acrylonitrile content effectively improves the water extraction resistance of antistatic plasticized PVC transparent elastic film, while also helping to reduce the surface resistivity and volume resistivity of the film, further enhancing its antistatic properties. ⑥ There are many types of nitrile rubber. Besides the basic requirement of selecting rubber for solution polymerization, nitrile rubber also comes in forms such as powder and block rubber, and is pre-crosslinked or uncrosslinked. This invention uses one or a combination of pre-crosslinked powdered nitrile rubber, uncrosslinked block nitrile rubber, or a combination thereof. Pre-crosslinked powdered nitrile rubber with a crosslinking degree of 40-55% helps improve film elasticity and reduce permanent deformation, more effectively preventing the antistatic plasticizer from being extracted by water. Compared to powdered nitrile rubber, block nitrile rubber has a larger molecular weight, thus better preventing the antistatic plasticizer from being extracted by water. Simultaneously, the addition of block nitrile rubber gives the film higher mechanical properties, such as tensile strength and elongation, especially a significant improvement in tear strength. Since the addition of high Mooney viscosity nitrile rubber inevitably reduces the flowability of plasticized PVC, selecting medium-to-low Mooney viscosity nitrile rubber with a Mooney viscosity ML(1+4) of 30-50 at 100℃ can avoid the negative flowability caused by its addition. ⑦ Using pre-crosslinked powdered nitrile rubber in combination with medium-to-low Mooney viscosity block nitrile rubber can also improve the antistatic properties of plasticized PVC transparent elastic film without affecting the film's water extraction resistance. The advantage of using both types of nitrile rubber is that it can maintain the contribution of pre-crosslinked powdered rubber to improving film elasticity and the contribution of block rubber to improving film strength, while ensuring that the film has good processing flowability. ⑧ Comparative Examples 2-6 show that the surface resistivity and volume resistivity of plasticized PVC transparent elastic films prepared using only non-antistatic plasticizers DEHP, DINP, DPHP, and PPA are 5.4 × 10⁻⁶. 13 Ω~2.3×10 15 Ω, 1.5×10 10 Ω·m~1.8×10 11 Ω·m, is typical of insulating films and lacks antistatic properties. In Comparative Examples 1 and 7, plasticized PVC transparent elastic films prepared using only or primarily the antistatic plasticizers DBEEA and DBEEG exhibit better antistatic properties, with surface resistivity and volume resistivity as low as 7.4 × 10⁻⁶. 9 Ω and 9.1×10 9 Ω, 5.1×10 6 Ω·m and 8.3×10 6It possesses excellent antistatic properties (Ω·m). However, plasticized PVC transparent elastic films prepared using only or primarily antistatic plasticizers DBEEA and DBEEG, without nitrile rubber, hydrophobic silica, and polyethylene wax, exhibit significantly reduced antistatic properties after immersion in water for 8 weeks, even reverting to insulating materials. In Comparative Examples 1 and 7, after immersion in water for 8 weeks, the surface resistivity and volume resistivity increased to 6.1 × 10⁻⁶. 12 Ω and 7.8×10 12 Ω, 2.1×10 9 Ω·m and 1.0×10 9 Ω·m, loss of antistatic function. Besides DEHP, a plasticizer that does not comply with RoHS directives, adding 3-10 parts of traditional non-antistatic plasticizers such as PPA, TOTM, DINP, DIDP, and DPHP does not affect the surface resistivity and transparency of the film, but can appropriately improve the extraction resistance of the antistatic plasticizer. In particular, polypropylene adipate plasticizers with a relatively high molecular weight and a number average molecular weight of 3000 are more effective and can further improve the elasticity of the film. ⑨ A small amount (3-5 parts) of a specific surface area of ​​350-410 m² 2 The addition of oleophilic and hydrophobic silica with a particle size of 7-10 nm does not affect the elasticity and antistatic properties of the plasticized PVC film. On the contrary, its high specific surface area and oleophilic porosity can absorb the precipitated plasticizers, maintaining the stability of the film's antistatic properties. Simultaneously, the physical structure and hydrophobic surface characteristics of nano-silica can increase the water contact angle of the film surface, isolating water from the film's contact surface and effectively preventing or slowing the precipitation of antistatic plasticizers DBEEA and DBEEG in water or high humidity environments, thus ensuring the stability of the film's antistatic properties in water or high humidity environments. ⑩ Non-oxidized low-density polyethylene wax with a melting point of 95-105℃ and a number-average molecular weight of 2000-3000 was chosen as the external lubricant for the following reasons: Firstly, the carboxyl content in oxidized polyethylene wax determines its compatibility with PVC resin; non-oxidized polyethylene wax contains almost no carboxyl groups and is completely incompatible with PVC resin, making it a typical external lubricant. Secondly, the plasticizer content used in the film formulation of this invention is all above 50 parts, and it also contains nitrile rubber. With a high plasticizer content, the film processing temperature is relatively low. Choosing a low-melting-point polyethylene wax ensures that the film migrates quickly to the surface in the later stages of processing, improving processing speed and efficiency. Finally, the high hydrophobicity of non-oxidized polyethylene wax synergistically reduces surface energy and increases the water contact angle of the film. This synergistic effect with nitrile rubber, non-antistatic plasticizers, nanoporous silica, and other additives prevents the antistatic plasticizer from being extracted by water.

[0035] In summary, the polymer matrix material of the plasticized PVC transparent elastic film of this invention is produced by suspension polymerization of PVC resin with an average degree of polymerization of 1300-1500, and is combined with pre-crosslinked powdered nitrile rubber with a degree of crosslinking of 40-55% and solution-polymerized uncrosslinked block nitrile rubber with a Mooney viscosity (ML(1+4)) of 30-50 at 100°C. Antistatic plasticizers DBEEA and DBEEG are used as the main plasticizers, supplemented with small amounts of traditional non-antistatic plasticizers such as PPA, TOTM, DINP, DIDP, and DPHP; further combined with small amounts of high specific surface area, oleophilic and hydrophobic nano-silica and low-melting-point, low-molecular-weight non-oxidized low-density polyethylene, etc., to prepare a plasticized PVC transparent elastic film with low surface resistivity and volume resistivity, high visible light transmittance and low haze, while maintaining stable antistatic properties in air, especially in water or high-humidity environments. The functional thin films prepared by this invention all exhibit water contact angles above 100°, visible light transmittance greater than 85%, and excellent resistance to water extraction. After immersion in water for 8 weeks, the water extraction rate of the prepared films is less than 4%, while the surface resistivity and volume resistivity are 7.5 × 10⁻⁶. 9 Ω~9.9×10 9 Ω, 5.1×10 6 Ω·m~8.8×10 6 Despite its low Ω·m, it still maintains excellent antistatic properties. The plasticized PVC functional film of this invention enriches the market demand for high-end antistatic, elastic, transparent, and other multifunctional films in electronics, electrical appliances, automotive, and construction industries. Detailed Implementation

[0036] The present invention is illustrated below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0037] Example 1

[0038] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 70, powdered nitrile rubber (AN=33%, pre-crosslinking degree 55%) 30, plasticizer DBEEA 60, organotin stabilizer 0.6, liquid calcium-zinc composite stabilizer 0.8, silica (specific surface area = 350m²) 2 / g)3, low-density non-oxidized polyethylene wax (melting point 95℃, Mn=2000)0.5.

[0039] Preparation process:

[0040] High-speed mixing of plasticized PVC powder: PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer are added to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 1 minute. Add half of the antistatic plasticizer DBEEA and switch to high-speed mixing mode, mixing thoroughly at 650 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining antistatic plasticizer DBEEA. After all the plasticizer is completely absorbed by the resin, add surface-modified porous silica and lubricant, continuing to mix thoroughly until the material temperature reaches 80℃. Observe the dryness of the powder; the optimal state is a dry consistency where it does not clump when squeezed by hand. Stop mixing at this point. Finally, transfer the thoroughly mixed material to an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 60 rpm. When the material cools to 40℃, add powdered nitrile rubber and continue mixing until it reaches 35℃ before discharging into the storage silo.

[0041] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for blending. The blending time in the internal mixer should be 3 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 40 r / min and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 170℃, and the machine return water temperature is 20℃ to prevent excessively high material temperature and melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0042] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 185℃, speed 10m / min; Roll 2 temperature control 185℃, speed 20m / min; Roll 3 temperature control 190℃, speed 30m / min; Roll 4 temperature control 150℃, speed 30m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 155℃, speed 40m / min; two second-stage drawing rollers, temperature control 155℃, speed 40m / min; two third-stage drawing rollers, 155℃, speed 45m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 45m / min, winding speed 50m / min.

[0043] Its performance was tested and is shown in Tables 1 and 2.

[0044] Example 2

[0045] Raw material formulation (mass ratio, parts): PVC resin (DP=1300) 70, solution polymerized block nitrile rubber (AN=26%, Mooney viscosity ML(1+4)100℃=30) 30, plasticizer DBEEG 50, polypropylene adipate plasticizer (M n =3000)5, organotin stabilizer 0.3, liquid calcium-zinc composite stabilizer 1.5, silicon dioxide (specific surface area = 400m²) 2 / g)3, low-density non-oxidized polyethylene wax (melting point 105℃, Mn=2500)0.5.

[0046] Preparation process:

[0047] High-speed mixing of plasticized PVC powder: PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer are added to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 400 rpm for 2 minutes. Add half of the antistatic plasticizer DBEEG and switch to high-speed mixing mode, mixing thoroughly at 900 rpm for 5 minutes. When the temperature reaches 60℃, add the remaining antistatic plasticizer DBEEG and the non-antistatic polyester plasticizer PPA. After all the plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant, continuing to mix thoroughly until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry consistency where it does not clump when squeezed by hand. Stop mixing at this point. Finally, transfer the thoroughly mixed material to an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 100 rpm. When the material cools to 45℃, discharge it into the storage silo.

[0048] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder and block nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 5 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 60 r / min and the open mill temperature at 175℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 180℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating that could lead to early PVC degradation.

[0049] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 5m / min; Roll 2 temperature control 180℃, speed 10m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 140℃, speed 25m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 40℃, speed 40m / min, winding speed 45m / min.

[0050] Its performance was tested and is shown in Tables 1 and 2.

[0051] Example 3

[0052] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 55, PVC resin (DP=1500) 30, powdered nitrile rubber (AN=41%, pre-crosslinking degree 40%) 15, plasticizer DBEEA 45, plasticizer DBEEG 10, plasticizer DINP 3, organotin stabilizer 0.5, liquid calcium-zinc composite stabilizer 1.0, silica (specific surface area = 410m²) 2 / g)5, Low-density non-oxidized polyethylene wax (melting point 95~105℃, Mn=2000~3000)0.6.

[0053] Preparation process:

[0054] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 350 rpm for 2 minutes. Add 30 parts of antistatic plasticizer DBEEA and switch to high-speed mixing mode to mix evenly, controlling the speed at 750 rpm for 4 minutes. When the temperature rises to 55℃, continue to add the remaining antistatic plasticizer DBEEA, DBEEG, and non-antistatic plasticizer DINP. After all the plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 85℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop stirring when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 80 rpm. When the material cools to 40°C, powdered nitrile rubber is added, and mixing continues until the material is discharged into the storage silo at 40°C.

[0055] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 140℃. Add the mixed plasticized PVC powder to the internal mixer for blending. The blending time in the internal mixer should be 3 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 40 r / min and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 170℃, and the machine return water temperature is 20℃ to prevent excessively high material temperature and melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0056] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 185℃, speed 10m / min; Roll 2 temperature control 188℃, speed 18m / min; Roll 3 temperature control 190℃, speed 28m / min; Roll 4 temperature control 150℃, speed 32m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 155℃, speed 40m / min; two second-stage drawing rollers, temperature control 155℃, speed 40m / min; two third-stage drawing rollers, 155℃, speed 45m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 45m / min, winding speed 50m / min.

[0057] Its performance was tested and is shown in Tables 1 and 2.

[0058] Example 4

[0059] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 70, powdered nitrile rubber (AN=26%, pre-crosslinking degree 50%) 15, solution-polymerized block nitrile rubber (AN=33%, Mooney viscosity ML(1+4)100℃=50) 15, plasticizer DBEEG 45, polypropylene adipate plasticizer (M n =3000)10, organotin stabilizer 0.6, liquid calcium-zinc composite stabilizer 1.0, silicon dioxide (specific surface area = 380m²) 2 / g)4, Low-density non-oxidized polyethylene wax (melting point 100℃, Mn=3000)0.6.

[0060] Preparation process:

[0061] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 300-400 rpm for 1 minute. Add 30 parts of antistatic plasticizer DBEEG and switch to high-speed mixing mode to mix evenly, controlling the speed at 700 rpm for 5 minutes. When the temperature rises to 60℃, continue to add the remaining antistatic plasticizer DBEEG and non-antistatic polyester plasticizer PPA. After all the plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 80℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop stirring when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 90 rpm. When the material cools to 40°C, powdered nitrile rubber is added, and mixing continues until the material is discharged into the storage silo at 40°C.

[0062] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 140℃. Add the mixed plasticized PVC powder and block nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 5 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 40 r / min and the open mill temperature at 175℃. 3. Due to the high plasticizer content and the presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 170℃, and the machine return water temperature is 20℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating that could lead to early PVC degradation.

[0063] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 190℃, speed 15m / min; Roll 2 temperature control 195℃, speed 30m / min; Roll 3 temperature control 195℃, speed 40m / min; Roll 4 temperature control 160℃, speed 40m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 160℃, speed 50m / min; two second-stage drawing rollers, temperature control 160℃, speed 50m / min; two third-stage drawing rollers, 160℃, speed 50m / min. The cooling and winding parameters are: cooling roller temperature control 60℃, speed 50m / min, winding speed 55m / min.

[0064] Its performance was tested and is shown in Tables 1 and 2.

[0065] Example 5

[0066] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 40, PVC resin (DP=1300) 40, powdered nitrile rubber (AN=41%, pre-crosslinking degree 45%) 20, plasticizer DBEEA 30, plasticizer DBEEG 20, plasticizer TOTM 5, organotin stabilizer 0.5, liquid calcium-zinc composite stabilizer 0.8, silica (specific surface area = 360m²) 2 / g)3, low-density non-oxidized polyethylene wax (melting point 95, Mn=2000) 0.5.

[0067] Preparation process:

[0068] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 350 rpm and the mixing time at 1 min. Add 30 parts of antistatic plasticizer EBEEA and switch to high-speed mixing mode to mix evenly, controlling the speed at 800 rpm and the mixing time at 3 min. When the temperature rises to 50-60℃, continue to add 20 parts of antistatic plasticizer DBEEG and non-antistatic plasticizer TOTM. After all the plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 90℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop stirring when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 70 rpm. When the material cools to 40°C, powdered nitrile rubber is added, and mixing continues until 45°C, at which point the material is discharged into the storage silo.

[0069] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for blending. The blending time in the internal mixer should be 3 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 60 r / min and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 170℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating that could lead to early PVC degradation.

[0070] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 185℃, speed 18m / min; Roll 3 temperature control 190℃, speed 30m / min; Roll 4 temperature control 155℃, speed 35m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 160℃, speed 42m / min; two second-stage drawing rollers, temperature control 160℃, speed 45m / min; two third-stage drawing rollers, 160℃, speed 50m / min. The cooling and winding parameters are: cooling roller temperature control 40℃, speed 50m / min, winding speed 55m / min.

[0071] Its performance was tested and is shown in Tables 1 and 2.

[0072] Example 6

[0073] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 70, powdered nitrile rubber (AN=33%, pre-crosslinking degree 50%) 20, block nitrile rubber (AN=36%, Mooney viscosity ML(1+4)100℃=40) 10, plasticizer DBEEG 50, polypropylene adipate plasticizer (M n =3000)3, Plasticizer DPHP 5, Organotin Stabilizer 0.4, Liquid Calcium-Zinc Composite Stabilizer 1.2, Silica (Specific Surface Area = 400m²) 2 / g)3, low-density non-oxidized polyethylene wax (melting point 98℃, Mn=2600)0.5.

[0074] Preparation process:

[0075] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 300 rpm for 2 minutes. Add 30 parts of antistatic plasticizer DBEEG and switch to high-speed mixing mode to mix evenly, controlling the speed at 900 rpm for 3 minutes. When the temperature rises to 60℃, continue to add the remaining antistatic plasticizer DBEEG, non-antistatic plasticizers PPA and DPHP. After all the plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 80℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop stirring when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 100rpm. When the material cools to 40℃, powdered nitrile rubber is added, and mixing continues until it reaches 40℃ before being discharged into the storage silo.

[0076] Plasticized PVC and Filtration: 1. Control the internal mixer temperature at 145℃. Add the mixed plasticized PVC powder and block nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 4 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 170℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 30℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating leading to early PVC degradation.

[0077] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 5m / min; Roll 2 temperature control 180℃, speed 10m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 140℃, speed 25m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 40℃, speed 40m / min, winding speed 4m / min.

[0078] Its performance was tested and is shown in Tables 1 and 2.

[0079] Example 7

[0080] Raw material formulation (mass ratio, parts): PVC resin (DP=1300) 75, powdered nitrile rubber (AN=30%, pre-crosslinking degree 48%) 25, plasticizer DBEEA 50, polypropylene adipate plasticizer (M n =3000)5, plasticizer DIDP5, organotin stabilizer 0.6, liquid calcium-zinc composite stabilizer 0.9, silica (specific surface area = 370m²) 2 / g)4, low-density non-oxidized polyethylene wax (melting point 95℃, Mn=2200)0.5.

[0081] Preparation process:

[0082] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 350 rpm and the mixing time at 2 minutes. Add 30 parts of antistatic plasticizer DBEEA and switch to high-speed mixing mode to mix evenly, controlling the speed at 750 rpm and the mixing time at 3-5 minutes. When the temperature rises to 55℃, continue to add the remaining antistatic plasticizer DBEEA, non-antistatic plasticizer PPA, and DIDP. After all the plasticizers have been completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 80℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop stirring when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 60 rpm. When the material cools to 40°C, powdered nitrile rubber is added, and mixing continues until 45°C, at which point the material is discharged into the storage silo.

[0083] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 145℃. Add the mixed plasticized PVC powder to the internal mixer for blending. The blending time in the internal mixer should be 5 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 40 rpm and the open mill temperature at 170℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 35℃ to prevent excessively high material temperature and melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0084] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 190℃, speed 15m / min; Roll 2 temperature control 195℃, speed 30m / min; Roll 3 temperature control 195℃, speed 40m / min; Roll 4 temperature control 160℃, speed 40m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 160℃, speed 50m / min; two second-stage drawing rollers, temperature control 160℃, speed 50m / min; two third-stage drawing rollers, 160℃, speed 50m / min. The cooling and winding parameters are: cooling roller temperature control 60℃, speed 50m / min, winding speed 55m / min.

[0085] Its performance was tested and is shown in Tables 1 and 2.

[0086] Example 8

[0087] Raw material formulation (mass ratio, parts): PVC resin (DP=1500) 70, powdered nitrile rubber (AN=33%, pre-crosslinking degree 50%) 10, block nitrile rubber (AN=41%, Mooney viscosity ML(1+4)100℃=35) 15, plasticizer DBEEA 30, plasticizer DBEEG 25, polypropylene adipate plasticizer (M n =3000)5, organotin stabilizer 0.5, liquid calcium-zinc composite stabilizer 1.2, silicon dioxide (specific surface area = 380m²) 2 / g)5, Low-density non-oxidized polyethylene wax (melting point 100℃, Mn=2000)0.6.

[0088] Preparation process:

[0089] High-speed mixing of plasticized PVC powder: PVC resin, liquid organotin stabilizer, and liquid calcium-zinc stabilizer are added to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add 30 parts of antistatic plasticizer DBEEA and switch to high-speed mixing mode, mixing evenly at 900 rpm for 3 minutes. When the temperature reaches 55℃, add antistatic plasticizer DBEEG and non-antistatic polyester plasticizer PPA. After all plasticizers are completely absorbed by the resin, add surface-modified porous silica and lubricant, continuing to mix evenly until the material temperature reaches 85℃. Observe the dryness of the powder; the optimal state is a dry consistency where it does not clump when squeezed by hand. Stop mixing. Finally, transfer the evenly mixed material to an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 100 rpm. When the material cools to 40℃, add powdered nitrile rubber and continue mixing until it reaches 40℃ before discharging into the storage silo.

[0090] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 145℃. Add the mixed plasticized PVC powder and block nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 5 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 60 r / min and the open mill temperature at 170℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 180℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating leading to early PVC degradation.

[0091] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 185℃, speed 10m / min; Roll 2 temperature control 185℃, speed 20m / min; Roll 3 temperature control 190℃, speed 30m / min; Roll 4 temperature control 150℃, speed 30m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 155℃, speed 40m / min; two second-stage drawing rollers, temperature control 155℃, speed 40m / min; two third-stage drawing rollers, 160℃, speed 45m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 45m / min, winding speed 50m / min.

[0092] Its performance was tested and is shown in Tables 1 and 2.

[0093] Comparative Example 1

[0094] Raw material formula (mass ratio, parts): PVC resin (DP=1000) 100, plasticizer DBEEA 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0095] Preparation process:

[0096] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the plasticizer DBEEA and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining DBEEA plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing evenly until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry state where it does not clump together when squeezed by hand. Stop mixing. Finally, discharge the evenly mixed material into an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 80 rpm, and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0097] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0098] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0099] Its performance was tested and is shown in Tables 3 and 4.

[0100] Comparative Example 2

[0101] Raw material formula (mass ratio, parts): PVC resin (DP=1300) 100, plasticizer DEHP 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0102] Preparation process:

[0103] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the DEHP plasticizer and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining DEHP plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry powder that does not clump when squeezed by hand. Stop mixing. Finally, transfer the evenly mixed material to an 800L jacketed, water-cooled low-speed mixer at 80 rpm and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0104] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0105] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0106] Its performance was tested and is shown in Tables 3 and 4.

[0107] Comparative Example 3

[0108] Raw material formula (mass ratio, parts): PVC resin (DP=1300) 100, plasticizer DINP 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0109] Preparation process:

[0110] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the plasticizer DINP and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining DINP plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry powder that does not clump when squeezed by hand. Stop mixing. Finally, transfer the evenly mixed material to an 800L jacketed low-speed mixer with circulating water cooling, controlling the speed at 80 rpm, and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0111] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0112] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0113] Its performance was tested and is shown in Tables 3 and 4.

[0114] Comparative Example 4

[0115] Raw material formula (mass ratio, parts): PVC resin (DP=1300) 100, plasticizer DPHP 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0116] Preparation process:

[0117] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the plasticizer DPHP and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining DPHP plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry powder that does not clump when squeezed by hand. Stop mixing. Finally, transfer the evenly mixed material to an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 80 rpm, and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0118] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0119] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0120] Its performance was tested and is shown in Tables 3 and 4.

[0121] Comparative Example 5

[0122] Raw material formula (mass ratio, parts): PVC resin (DP=1300) 100, plasticizer TOTM 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0123] Preparation process:

[0124] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the TOTM plasticizer and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining TOTM plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry powder that does not clump when squeezed by hand. Stop mixing. Finally, transfer the evenly mixed material to an 800L low-speed mixer with jacketed circulating water cooling, controlling the speed at 80 rpm, and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0125] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0126] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0127] Its performance was tested and is shown in Tables 3 and 4.

[0128] Comparative Example 6

[0129] Raw material formula (mass ratio, parts): PVC resin (DP=1300) 100, plasticizer PPA 60, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2.

[0130] Preparation process:

[0131] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode at 300 rpm for 2 minutes. Add half of the plasticizer PPA and switch to high-speed mixing mode to mix evenly at 800 rpm for 3 minutes. When the temperature reaches 50℃, add the remaining PPA plasticizer. After all the plasticizer is completely absorbed by the resin, add lubricant and continue mixing evenly until the material temperature reaches 90℃. Observe the dryness of the powder; the optimal state is a dry state where it does not clump together when squeezed by hand. Stop mixing. Finally, discharge the evenly mixed material into an 800L jacketed low-speed mixer with circulating water cooling, controlling the speed at 80 rpm, and continue mixing until the temperature reaches 35℃ before discharging into the storage silo.

[0132] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder to the internal mixer for melt plasticization. The mixing time in the internal mixer should be 4 minutes. 2. The mixed material from the internal mixer is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature and high melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0133] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0134] Its performance was tested and is shown in Tables 3 and 4.

[0135] Comparative Example 7

[0136] Raw material formulation (mass ratio, parts): PVC resin (DP=1300) 95, powdered nitrile rubber (AN=26%, pre-crosslinking degree 50%) 5, plasticizer DBEEG 50, plasticizer PPA 10, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2, silica (specific surface area = 350m²) 2 / g,ML(1+4)100℃=50)2.

[0137] Preparation process:

[0138] High-speed mixing of plasticized PVC powder: Add PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer to a 500L hot-mix high-speed mixer. First, start the low-speed mixing mode, controlling the speed at 300 rpm for 2 minutes. Add 30 parts of plasticizer DBEEG and switch to high-speed mixing mode to mix evenly, controlling the speed at 800 rpm for 3 minutes. When the temperature rises to 50℃, continue to add the remaining 20 parts of plasticizer DBEEG and 10 parts of plasticizer PPA. After all the plasticizers have been completely absorbed by the resin, add surface-modified porous silica and lubricant and continue mixing evenly until the material temperature rises to 90℃. Observe the dryness and wetness of the powder. The optimal state is a dry state where it does not clump together when squeezed by hand. Stop mixing when this state is reached. Finally, the well-mixed material is discharged into an 800L low-speed mixer with jacketed circulating water cooling, and the speed is controlled at 80 rpm. When the material cools to 40°C, powdered nitrile rubber is added, and mixing continues until 35°C before being discharged into the storage silo.

[0139] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder containing powdered nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 4 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and nitrile rubber content in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperature, high melt strength, and excessive frictional heating that could lead to early PVC degradation.

[0140] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0141] Its performance was tested and is shown in Tables 3 and 4.

[0142] Comparative Example 8

[0143] Raw material formula (mass ratio, parts): PVC resin (DP=1000) 70, emulsion block nitrile rubber (AN=33%) 30, plasticizer DBEEA 10, plasticizer PPA 50, organotin stabilizer 0.8, calcium stearate 1.5, zinc stearate 0.2, silicon dioxide 2.

[0144] Preparation process:

[0145] High-speed mixing of plasticized PVC powder: PVC resin, liquid organotin stabilizer, calcium stearate, and zinc stearate stabilizer are added to a 500L hot-mix high-speed mixer. First, the low-speed mixing mode is started, with a speed controlled at 300 rpm and a mixing time of 2 minutes. Then, 10 parts of plasticizer DBEEA and 20 parts of plasticizer PPA are added, and the mixture is switched to high-speed mixing mode and mixed thoroughly, with a speed controlled at 800 rpm and a mixing time of 3 minutes. When the temperature reaches 50℃, the remaining 30 parts of plasticizer PPA are added. After all the plasticizers are completely absorbed by the resin, surface-modified porous silica and lubricant are added, and mixing continues until the material temperature reaches 90℃. The dryness of the powder is observed; the optimal state is a dry state where it does not clump together when squeezed by hand. Finally, the thoroughly mixed material is discharged into an 800L low-speed mixer with a jacketed circulating water cooling system, with a speed controlled at 80 rpm. When the material cools to 40℃, it is discharged into a storage silo.

[0146] Plasticized PVC Plasticization and Filtration: 1. Control the internal mixer temperature at 150℃. Add the mixed plasticized PVC powder and emulsion-processed block nitrile rubber to the internal mixer for blending. The blending time in the internal mixer should be 4 minutes. 2. The blended material is then transferred to an open mill for further plasticization. Control the open mill roller speed at 50 rpm and the open mill temperature at 165℃. 3. Due to the high plasticizer content and presence of nitrile rubber in the elastic film, the filter screen uses a three-layer laminated metal filter with mesh sizes of 20, 100, and 20. The filter temperature is controlled at 175℃, and the machine return water temperature is 40℃ to prevent excessively high material temperatures and melt strength, which could lead to excessive frictional heating and premature PVC degradation.

[0147] Film calendering: The material filtered by the filter press is conveyed to the calendering machine along the conveyor belt. After calendering, drawing and embossing, cooling and winding, an antistatic plasticized PVC transparent elastic film is obtained. The film forming parameters of the four-roll calender are: Roll 1 temperature control 180℃, speed 10m / min; Roll 2 temperature control 180℃, speed 15m / min; Roll 3 temperature control 185℃, speed 20m / min; Roll 4 temperature control 150℃, speed 20m / min. The drawing and embossing parameters are: one first-stage drawing roller, temperature control 150℃, speed 30m / min; two second-stage drawing rollers, temperature control 150℃, speed 30m / min; two third-stage drawing rollers, 150℃, speed 40m / min. The cooling and winding parameters are: cooling roller temperature control 50℃, speed 40m / min, winding speed 45m / min.

[0148] Its performance was tested and is shown in Tables 3 and 4.

[0149] Table 1. Overview of the electrical properties and plasticizer water extraction properties of the films prepared in Examples 1 to 8.

[0150]

[0151] * Rate of mass change when exposed to air for different times; ** Rate of mass change when immersed in water for different times.

[0152] Table 2. Summary of the mechanical properties, transparency, and elastic properties of the films prepared in Examples 1 to 8.

[0153]

[0154] Table 3. Summary of the electrical properties and plasticizer water extraction properties of the films prepared in Comparative Examples 1 to 8

[0155]

[0156] * Rate of mass change when exposed to air for different times; ** Rate of mass change when immersed in water for different times.

[0157] Table 4. Summary of mechanical properties, transparency, and elastic properties of the films prepared in Comparative Examples 1 to 8

[0158]

Claims

1. An antistatic plasticized polyvinyl chloride transparent elastic film, characterized by, The raw materials are prepared by the following mass ratio: The preparation method of the anti-static plasticized PVC transparent elastic film comprises the following steps: Plasticized PVC powder high-speed mixing: put polyvinyl chloride resin and liquid organic tin stabilizer and liquid calcium-zinc stabilizer into a 500L hot mixing type high-speed mixer, first start the low-speed mixing mode, control the rotating speed at 300-400 rpm, and the mixing time is 1-2 min; add half of the anti-static plasticizer and switch to the high-speed mixing mode to mix uniformly, control the rotating speed at 650-900 rpm, and the mixing time is 3-5 min; when the temperature rises to 50-60℃, continue to add the remaining anti-static plasticizer and non-anti-static plasticizer; when all the plasticizers are completely absorbed by the resin, add surface modified porous silica and lubricant to continue mixing uniformly, until the material temperature rises to 80-90℃, observe the dry and wet state of the powder, and stop stirring when the best state is dry and comfortable without forming a group in hand; finally, discharge the uniformly mixed material to an 800L low-speed mixer with jacket circulating water cooling, control the rotating speed at 60-100 rpm; if pre-crosslinked powdered butyl rubber is used, add the pre-crosslinked powdered butyl rubber when the material cools to 40℃, continue to mix to 40±5℃, and discharge to the storage bin to obtain the mixed plasticized PVC powder material; Plasticized PVC plasticization and filtration: 1) control the temperature of the internal mixer at 140-150℃, if uncrosslinked block butyl rubber is used, add it at this time and blend with the mixed plasticized PVC powder material in the internal mixer, and the internal mixer blending time is 3-5 min; 2) the material blended by the internal mixer is transported to the open mill for further plasticization, control the rotating speed of the open mill roller at 40-60 r / min, and the open mill temperature is 165-175℃; 3) because the plasticizer content in the elastic film is high and contains butyl rubber, the filter screen adopts three layers of stacked metal filter screens, and the mesh numbers of the screens are 20, 100 and 20 respectively; the filter screen temperature is controlled at 170-180℃, and the machine body backwater temperature is 20-40℃ to prevent the material temperature from being too high, which may cause early degradation of PVC due to high melt strength and high friction temperature rise; Film calendering: the material filtered by the rubber filter is conveyed to the calender main machine along the conveying belt, and the antistatic plasticized PVC transparent elastic film is obtained after film forming, leading off and embossing, cooling and winding; the film forming parameters of the four-roll calender are: 1# roll temperature control 180-190℃, speed 5-15m / min, 2# roll temperature control 180-195℃, speed 10-30m / min, 3# roll temperature control 185-195℃, speed 20-40m / min, 4# roll temperature control 140-160℃, speed 25-40m / min; the leading off and embossing parameters are: one section leading off wheel 1, temperature control 150-160℃, speed 30-50m / min; two section leading off wheel 2, temperature control 150-160℃, speed 30-50m / min; three section leading off wheel 2, 150-160℃, speed 40-50m / min; the cooling and winding parameters are: cooling roll temperature control 40-60℃, speed 40-50m / min, winding speed 45-55m / min.

2. The antistatic plasticized PVC transparent elastic film according to claim 1, characterized in that, The PVC resin is a linear PVC resin with an average polymerization degree of 1300-1500 or a combination thereof, which is synthesized by suspension polymerization process.

3. The antistatic plasticized PVC transparent elastic film according to claim 1, characterized in that, The nitrile rubber is a binary random copolymer obtained by using butadiene and acrylonitrile as monomers and by solution polymerization method, wherein the mass percentage content of acrylonitrile is 26-41%.

4. The antistatic plasticized PVC transparent elastic film according to claim 3, characterized in that, The nitrile rubber is one or a combination of pre-crosslinked powder nitrile rubber and uncrosslinked block nitrile rubber; wherein the pre-crosslinked powder nitrile rubber has a crosslinking degree of 40-55%; the uncrosslinked block nitrile rubber has a medium-low Mooney viscosity ML(1+4)100℃ of 30-50.

5. The antistatic plasticized PVC transparent flexible film according to claim 1, characterized in that, The antistatic plasticizer is one or a combination of dibutyl adipate and dibutyl glutarate.

6. The antistatic plasticized PVC transparent flexible film according to claim 1, characterized in that, The non-antistatic plasticizer is a polyester plasticizer, trioctyl trimellitate, diisononyl phthalate, diisodecyl phthalate or di(2-propyl heptyl) phthalate.

7. The antistatic plasticized PVC transparent flexible film according to claim 6, characterized in that, The non-antistatic plasticizer is a relatively high molecular weight polyester plasticizer, i.e. polypropylene adipate with a number average molecular weight of 3000.

8. The antistatic plasticized PVC transparent flexible film according to claim 1, characterized in that, The surface-modified porous silica is a lipophilic hydrophobic silica with a purity of more than 99.8%, a specific surface area of 350-410 m 2 / g, a primary particle size of 7-10 nm, and a lipophilic hydrophobic type.

9. The antistatic plasticized PVC transparent flexible film according to claim 1, characterized in that, The lubricant is a non-oxidized low-density polyethylene wax with a melting point of 95-105℃ and a number average molecular weight of 2000-3000.

10. A process for the preparation of an antistatic, plasticized, transparent, flexible polyvinyl chloride film according to any one of claims 1 to 9, characterized in that The method comprises the following steps: The method comprises the following steps: Plasticized PVC powder high-speed mixing: Put polyvinyl chloride resin and liquid organic tin stabilizer, liquid calcium-zinc stabilizer into a 500L hot mixing type high-speed mixer, first start the low-speed mixing mode, control the speed to 300-400 rpm, and mix for 1-2 min; Add half of the antistatic plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650-900 rpm, and mix for 3-5 min; When the temperature rises to 50-60℃, continue to add the remaining antistatic plasticizer and non-antistatic plasticizer; When all the plasticizers are completely absorbed by the resin, add surface modified porous silica and lubricant and continue to mix evenly until the material temperature rises to 80-90℃, then stop stirring when the powder is dry and not clumped; Finally, discharge the mixed material to an 800L low-speed mixer with jacketed circulating water cooling, control the speed to 60-100 rpm; If pre-crosslinked powdered nitrile rubber is used, add it when the material cools to 40℃, continue to mix until 40±5℃, and discharge to the storage bin to obtain the mixed plasticized PVC powder material; Plasticized PVC plasticization and filtration: 1) Control the temperature of the internal mixer to 140-150℃, if uncrosslinked block nitrile rubber is used, add it at this time and blend with the mixed plasticized PVC powder material in the internal mixer, the internal mixer blending time is 3-5 min; 2) The material blended in the internal mixer is transported to the open mill for further plasticization, control the roller speed of the open mill to 40-60 r / min, and the temperature of the open mill to 165-175℃; 3) Because the elastic film has a high plasticizer content and contains nitrile rubber, the filter screen uses three layers of stacked metal screens with mesh sizes of 20, 100, and 20 respectively; The filter temperature is controlled at 170-180℃, and the machine body backwater temperature is 20-40℃ to prevent the material temperature from being too high, which may cause early degradation of PVC due to high melt strength and high friction temperature. Film calendering forming: the material filtered by the filter is conveyed to the calendering main machine along the conveying belt, and the antistatic plasticized PVC transparent elastic film is obtained after film forming, leading off and embossing, cooling and winding; the film forming parameters of the four-roll calendering machine are: the temperature of 1# roll is controlled at 180-190 ℃, the speed is 5-15 m / min, the temperature of 2# roll is controlled at 180-195 ℃, the speed is 10-30 m / min, the temperature of 3# roll is controlled at 185-195 ℃, the speed is 20-40 m / min, and the temperature of 4# roll is controlled at 140-160 ℃, the speed is 25-40 m / min; the leading off and embossing parameters are: one section of leading off wheel 1, the temperature is controlled at 150-160 ℃, the speed is 30-50 m / min; two sections of leading off wheel 2, the temperature is controlled at 150-160 ℃, the speed is 30-50 m / min; three sections of leading off wheel 2, 150-160 ℃, the speed is 40-50 m / min; the cooling and winding parameters are: the temperature of cooling roll is controlled at 40-60 ℃, the speed is 40-50 m / min, and the winding speed is 45-55 m / min.

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