Corrosion-resistant substitute PVC membrane and its production process

Abstract

The application relates to a corrosion-resistant substitute PVC film and a production process thereof, and belongs to the technical field of polymer film materials. The film material comprises the following components in parts by weight: 100 parts of PET resin, 3.2-4.5 parts of an organic silicon corrosion-resistant agent, 0.3-0.5 parts of a slip agent, 0.15-0.2 parts of a nucleating agent and 4-6 parts of a filler; the organic silicon corrosion-resistant agent is obtained by ring-opening of N-methyldiethanolamine and terminal epoxy silicone oil, forming an organic silicon compound with N-methyldiethanolamine as a bridging chain segment, namely an organic silicon matrix, then by ring-opening and capping of a residual terminal epoxy group of the organic silicon matrix with an active primary amine of tetramethylpiperidylamine, a functional end amine structure is introduced, namely a functional intermediate is obtained, finally by esterification of the hydroxyl group after ring-opening of oxalyl chloride monoethyl ester and the functional intermediate, a double-ester short-chain modification is introduced to the molecular side chain of the functional intermediate, and the introduction of the organic silicon corrosion-resistant agent improves the medium corrosion resistance and aging corrosion resistance of the film material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polymer film materials, and particularly relates to a corrosion-resistant PVC film substitute and a production process thereof. BACKGROUND

[0002] Polyvinyl chloride (PVC) film is a common film material and is widely used in the fields of building decoration, packaging, medical treatment, electronics and the like. However, the pure PVC material has high hardness and great brittleness, and a large amount of plasticizer needs to be added in the general PVC film material, and the plasticizer is easy to separate out and cause harm to the environment, and the PVC material itself is difficult to biodegrade and will be accumulated in the environment for a long time after being abandoned, causing white pollution. The PVC material contains a large amount of chlorine elements, and the chlorine elements will release toxic dioxin and hydrogen chloride gas in the incineration process, causing serious harm to the environment and human health.

[0003] Compared with the PVC film, polyethylene terephthalate (PET) film is a recyclable and environmentally friendly material, and has similar characteristics to the PVC film. However, the main chain of the PET film is mainly ester chain, and the PET film has good degradation prospect. The PET film does not need to be plasticized, and has high strength and good thermal stability, and is an optimal substitute for the PVC film. However, the PET molecule chain contains a large amount of ester structure, and the PET film is easy to be corroded by acid and alkali and the like. The benzene ester structure is easy to age in a light and heat environment, and the corrosion resistance of the PET film material is insufficient, which greatly limits the substitution of the PET film material for the PVC film material. In the prior art, corrosion-resistant substances such as inorganic fillers, organic silicon and light stabilizers are generally used to modify the PET film material to improve the corrosion resistance of the PET film material. However, the compatibility of the substances with the PET matrix is insufficient, and the effect is not obvious. SUMMARY

[0004] In order to solve the technical problems mentioned in the background, the purpose of the application is to provide a corrosion-resistant PVC film substitute and a production process thereof.

[0005] The purpose of the application can be achieved by the following technical solutions.

[0006] The corrosion-resistant PVC film substitute comprises, in terms of weight parts, PET resin 100 parts, organic silicon corrosion-resistant agent 3.2-4.5 parts, slip agent 0.3-0.5 parts, nucleating agent 0.15-0.2 parts and filler 4-6 parts.

[0007] The organic silicon corrosion-resistant agent is prepared by the following method.

[0008] Step A1: The terminal epoxy silicone oil and acetone are premixed, heated to 55-65 DEG C, and stirred at 60-90 rpm. N-methyl diethanolamine is slowly added and reacted for 3-4.5 h. After the reaction is completed, the acetone is removed by evaporation under reduced pressure to obtain an organic silicon matrix.

[0009] Further, the epoxy group content of the terminal epoxy silicone oil, the amount ratio of N-methyldiethanolamine and acetone is 0.1 mol:36-42 mmol:40-55 mL, and the tertiary amine structure in the N-methyldiethanolamine molecule promotes the ring opening of the terminal epoxy silicone oil to form an organic silicon compound with N-methyldiethanolamine as a bridging segment;

[0010] Further, the terminal epoxy silicone oil is a low molecular weight silicone oil, and the room temperature viscosity is not higher than 50 mm 2 / s, and the terminal epoxy silicone oil in this state maintains good reactivity, and the formed silicone chain is easy to disperse in the film material matrix.

[0011] Step A2: Mix the silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide, protect with nitrogen, heat to 80-95°C, apply 120-150 rpm stirring, react for 1.5-2h, after reaction, separate the water phase and dry under vacuum to obtain the functionalized intermediate;

[0012] Further, the amount ratio of the silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide is 100 g:8-12 mL:0.2-0.3 g:60-90 mL, and under the promotion of triphenylphosphine, the active primary amine of tetramethylpiperidylamine continues to ring open and cap the terminal residual epoxy group of the silicone matrix.

[0013] Step A3: Mix the functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene, protect with dry nitrogen, apply 30-50 rpm stirring, heat to 45-60°C for 2-3h, then reduce the pressure to 1 kPa, continue to heat to 75-90°C for 1.2-1.5h, after reaction, remove toluene by rotary evaporation to obtain the silicone corrosion inhibitor;

[0014] Further, the amount ratio of the functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene is 100 g:20-30 mL:0.12-0.16 g:50-70 mL, and under the promotion of tetraethyl titanate, the oxalyl chloride monoethyl ester esterifies with the hydroxyl group after ring opening of the functionalized intermediate.

[0015] Preferably, the slip agent is selected from stearic acid amide.

[0016] Preferably, the filler is selected from oil-wet nano-silicon dioxide.

[0017] A production process of a corrosion-resistant alternative PVC film, specifically comprising the following steps:

[0018] Step S1: Mix the PET resin, silicone corrosion inhibitor, slip agent, nucleating agent and filler by high-speed mixer, then transfer into a banbury mixer, mix at 260°C until the torque is stable, discharge and pelletize to obtain the composite master batch;

[0019] Step S2: melt-extruding the composite master batch into a cast sheet, calendering the cast sheet to a predetermined thickness to form a blank film, and then stretch-forming the blank film to obtain the corrosion-resistant substitute PVC film.

[0020] The present application has the following beneficial effects:

[0021] The present application discloses a PET base film material, by introducing a self-developed organic silicon corrosion inhibitor to improve the medium corrosion resistance and aging corrosion resistance of the film material, so that the PET film material can effectively replace the traditional PVC film material in some corrosion working conditions; the organic silicon corrosion inhibitor is obtained by ring-opening of N-methyldiethanolamine and epoxy-terminated silicone oil to form an organic silicon compound with N-methyldiethanolamine as a bridging segment, i.e., an organic silicon matrix, then by ring-opening of the active primary amine of tetramethylpiperidylamine and the terminal residual epoxy group of the organic silicon matrix to introduce a functional blocked amine structure, i.e., a functional intermediate, and finally by esterification of oxalyl chloride monoethyl ester and the hydroxyl group after ring-opening of the functional intermediate to introduce a double ester short chain modification to the molecular side chain of the functional intermediate, the double ester short chain is compatible with the PET matrix macromolecule, and in the blending process, the organic silicon main chain of the organic silicon corrosion inhibitor can be fully dispersed in the matrix, the organic silicon chain itself has good corrosion resistance, and after uniform dispersion, it plays a shielding and protective role for the matrix, at the same time, it is a macromolecular segment, which is inserted in the macromolecular network of the matrix to play a connecting role, reducing the problem of rapid deterioration of the mechanical properties of the matrix caused by corrosion, in addition, due to good dispersibility, the organic silicon corrosion inhibitor uniformly introduces a blocked amine structure into the matrix, effectively improving the aging corrosion resistance of the matrix. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Example 1, preparation of a corrosion-resistant substitute PVC film, the specific implementation process is as follows:

[0024] (1) Preparation of the organic silicon corrosion inhibitor

[0025] Step A1: pre-mix the epoxy-terminated silicone oil and acetone, heat to 65℃, apply 90rpm stirring, then slowly add N-methyldiethanolamine, control the addition time to be 2.5h, continue constant temperature stirring reaction after complete addition, control the addition reaction time of N-methyldiethanolamine to be 4.5h, wherein the epoxy-terminated silicone oil is selected from X-22-163A silicone oil, the room temperature viscosity is about 30mm 2 / s, the epoxy content of the terminal epoxy silicone oil, the amount ratio of N-methyldiethanolamine and acetone is 0.1 mol:42 mmol:55 mL, the reaction is ended, and acetone is removed by evaporation under reduced pressure to obtain a silicone matrix.

[0026] Step A2: The silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide are mixed, nitrogen is introduced for protection, the temperature is raised to 95°C, stirring is applied at 150 rpm, and the reaction is carried out for 2 h, wherein the amount ratio of the silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide is 100 g:8 mL:0.3 g:90 mL, the reaction is ended, water washing is applied for liquid separation, the water phase is removed and vacuum drying is applied to obtain a functionalized intermediate.

[0027] Step A3: The functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene are mixed, dry nitrogen is introduced for protection, stirring is applied at 50 rpm, the temperature is raised to 60°C, and the reaction is carried out for 3 h, then the pressure is reduced to 1 kPa, the temperature is raised to 90°C, and the reaction is continued for 1.5 h, wherein the amount ratio of the functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene is 100 g:20 mL:0.16 g:70 mL, the reaction is ended, and toluene is removed by rotary evaporation to obtain a silicone corrosion inhibitor.

[0028] (2) Preparation of the film material

[0029] Step S1: The raw materials are taken according to weight parts, 100 parts of PET resin is used in the implementation process, 4.5 parts of silicone corrosion inhibitor is self-made in the implementation process, 0.3 parts of slip agent is used in the implementation process, 0.2 parts of nucleating agent is used in the implementation process, 4 parts of filler is used in the implementation process, the raw materials are added into a high-speed mixer to mix for 10 min at 800 rpm, and then transferred into a mixing kettle to mix for 25 min at 260°C, the torque tends to be stable, the material is discharged and pelletized to obtain a composite master batch.

[0030] Step S2: The composite master batch is melt-extruded into a sheet at 280°C, calendered to a certain thickness to obtain a base film with a thickness of 0.2 mm, and then stretched to form a corrosion-resistant substitute PVC film, wherein the stretching ratio is controlled to be 3.5.

[0031] Example 2, a corrosion-resistant substitute PVC film is prepared, and the specific implementation process is as follows:

[0032] (1) Preparation of the silicone corrosion inhibitor

[0033] Step A1: take the end epoxy silicone oil and acetone premix, temperature to 55℃, apply 60 rpm stirring, then slowly add N-methyl diethanolamine, control the adding time is 1.5h, after complete adding continue constant temperature stirring reaction, control N-methyl diethanolamine adding reaction time is 3h, wherein, the end epoxy silicone oil is selected from KF-105 type silicone oil, room temperature viscosity is about 15mm 2 / s, the amount ratio of the epoxy group content of the end epoxy silicone oil, N-methyl diethanolamine and acetone is 0.1mol:36mmol:40mL, after the reaction is completed, remove acetone by evaporation under reduced pressure to obtain a silicone matrix.

[0034] Step A2: take the silicone matrix, tetramethylpiperidinamine, triphenylphosphine and dimethylacetamide mixture, nitrogen protection, temperature to 80℃, apply 120 rpm stirring, reaction 1.5h, wherein, the amount ratio of the silicone matrix, tetramethylpiperidinamine, triphenylphosphine and dimethylacetamide is 100g:12mL:0.2g:60mL, after the reaction is completed, water washing and liquid separation, remove the water phase and vacuum drying to obtain a functionalized intermediate.

[0035] Step A3: take the functionalized intermediate, oxalyl chloride monoethyl ester, titanium tetraethoxide and anhydrous toluene mixture, dry nitrogen protection, apply 30 rpm stirring, temperature to 45℃ reaction 2h, then reduce to 1kPa, continue to heat to 75℃ reaction 1.2h, wherein, the amount ratio of the functionalized intermediate, oxalyl chloride monoethyl ester, titanium tetraethoxide and anhydrous toluene is 100g:30mL:0.12g:50mL, after the reaction is completed, remove toluene by rotary evaporation to obtain a silicone corrosion inhibitor.

[0036] (2) Preparation of film material

[0037] Process S1: take the raw materials according to weight parts, PET resin 100 parts, TRN-RTJ type resin raw material is used in the implementation process; silicone corrosion inhibitor 3.2 parts, self-made in this embodiment; slip agent 0.5 parts, industrial grade stearic acid amide is used in the implementation process; nucleating agent 0.15 parts, Sanulater HK195 type composite metal salt nucleating agent is used in the implementation process; filler 6 parts, VK-SP30S type lipophilic nano silica is used in the implementation process; add each raw material to the high mixer to mix for 10 min at 800 rpm, then transfer to the internal mixer and mix at 260℃ for 25 min, the torque tends to be stable, discharge and pelletize to obtain a composite master batch.

[0038] Process S2: melt extrude the composite master batch at 280℃ to obtain a cast sheet, calender to a certain thickness to obtain a base film with a thickness of 0.2mm, then stretch the base film to form a corrosion resistant substitute PVC film, and control the stretching ratio to be 3.5.

[0039] Example 3, preparation of corrosion-resistant alternative PVC film, the specific implementation process as follows:

[0040] (1) Preparation of silicone corrosion inhibitor

[0041] Step A1: take the end of the epoxy silicone oil and acetone premix, temperature to 50℃, apply 60 rpm stirring, then slowly add N-methyl diethanolamine, control the adding time for 2h, continue to constant temperature stirring reaction after complete, control N-methyl diethanolamine adding reaction time for 3.5h, wherein, the end of the epoxy silicone oil is selected from KF-105 type silicone oil, the room temperature viscosity is about 15mm 2 / s, the epoxy group content of the end of the epoxy silicone oil, the amount of N-methyl diethanolamine and acetone is 0.1mol:40mmol:50mL, reaction end, remove acetone by evaporation under reduced pressure, get silicone matrix.

[0042] Step A2: take the silicone matrix, tetramethyl piperidylamine, triphenylphosphine and dimethylacetamide mixed, nitrogen protection, temperature to 85℃, apply 120 rpm stirring, reaction 1.8h, wherein, the amount of silicone matrix, tetramethyl piperidylamine, triphenylphosphine and dimethylacetamide is 100g:10mL:0.25g:80mL, reaction end, water washing, remove the water phase and vacuum drying, get functional intermediate.

[0043] Step A3: take the functional intermediate, oxalyl chloride monoethyl ester, titanium tetrabutoxide and anhydrous toluene mixed, dry nitrogen protection, apply 30 rpm stirring, temperature to 50℃ reaction 2.8h, then reduce to 1kPa, continue to heat to 80℃ reaction 1.4h, wherein, the amount of functional intermediate, oxalyl chloride monoethyl ester, titanium tetrabutoxide and anhydrous toluene is 100g:25mL:0.14g:60mL, reaction end, remove toluene by rotary evaporation, get silicone corrosion inhibitor.

[0044] (2) Preparation of film material

[0045] Process S1: according to the weight part, take the raw material, PET resin 100 parts, TRN-RTJ type resin raw material is used in the implementation process; silicone corrosion inhibitor 3.8 parts, made by the example; slip agent 0.4 parts, industrial grade stearic acid amide is used in the implementation process; nucleating agent 0.17 parts, Sanulater HK195 type composite metal salt nucleating agent is used in the implementation process; filler 5 parts, VK-SP30S type lipophilic nano silicon dioxide is used in the implementation process; put each raw material into high speed mixer to mix for 10 min at 800 rpm, then transfer into the mixing kettle and mix at 260℃ for 25 min, the torque tends to be stable, discharge and cut into particles, get the composite master batch.

[0046] Process S2: melt-extruding the composite master batch at 280°C to form a cast sheet, calendering the cast sheet to a thickness of 0.2 mm to form a base film, and then stretching the base film to form a corrosion-resistant substitute PVC film, with a stretching ratio of 3.5.

[0047] Example 4: Preparation of a corrosion-resistant substitute PVC film, with the following specific implementation process:

[0048] (1) Preparation of a silicone corrosion inhibitor

[0049] Step A1: Pre-mixing terminal epoxy silicone oil and acetone, heating to 60°C, applying 90 rpm stirring, slowly adding N-methyl diethanolamine, controlling the addition time to be 2.2 h, continuing constant temperature stirring after complete addition, controlling the addition reaction time of N-methyl diethanolamine to be 3.5 h, wherein the terminal epoxy silicone oil is selected from KF-105 type silicone oil, the room temperature viscosity is about 15 mm 2 / s, the ratio of the epoxy content of the terminal epoxy silicone oil, N-methyl diethanolamine and acetone is 0.1 mol:40 mmol:55 mL, and the reaction is ended by removing acetone under reduced pressure to obtain a silicone matrix.

[0050] Step A2: Mixing the silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide, purging with nitrogen, heating to 88°C, applying 150 rpm stirring, reacting for 2 h, wherein the ratio of the silicone matrix, tetramethylpiperidylamine, triphenylphosphine and dimethylacetamide is 100 g:12 mL:0.3 g:80 mL, the reaction is ended by water washing and liquid separation, removing the water phase and vacuum drying to obtain a functionalized intermediate.

[0051] Step A3: Mixing the functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene, purging with dry nitrogen, applying 50 rpm stirring, heating to 55°C for 2.2 h, then reducing the pressure to 1 kPa, continuing to heat to 85°C for 1.3 h, wherein the ratio of the functionalized intermediate, oxalyl chloride monoethyl ester, tetraethyl titanate and anhydrous toluene is 100 g:30 mL:0.15 g:60 mL, the reaction is ended by removing toluene by rotary evaporation to obtain a silicone corrosion inhibitor.

[0052] (2) Preparation of a film material

[0053] Process S1: Take raw materials according to parts by weight, 100 parts of PET resin, TRN-RTJ type resin raw material is used in the implementation process; 4.2 parts of organic silicon corrosion resistant agent, which is self-made in this embodiment; 0.4 parts of slip agent, industrial grade stearic acid amide is used in the implementation process; 0.2 parts of nucleating agent, Sanulater HK195 type composite metal salt nucleating agent is used in the implementation process; 5.5 parts of filler, VK-SP30S type lipophilic nano silicon dioxide is used in the implementation process; add each raw material into the high mixer to mix for 10 min at 800 rpm, then transfer into the internal mixer to mix for 25 min at 260℃, the torque tends to be stable, discharge and pelletize to obtain the composite master batch.

[0054] Process S2: melt extrude the composite master batch at 280℃ to obtain a cast sheet, calender to a certain thickness to obtain a base film with a thickness of 0.2 mm, then stretch the base film to form a corrosion resistant PVC film with a stretching ratio of 3.5.

[0055] Comparative Example

[0056] The comparative example refers to example 4, without adding organic silicon corrosion resistant agent, adding 3.5 parts of side chain acrylate modified silicone oil IOTA 170, 0.2 parts of light stabilizer 770 and 0.8 parts of PL-215 type silicone powder, and the rest of the implementation process is the same as example 4.

[0057] Take the above film material to test the medium corrosion resistance and aging corrosion resistance, as follows:

[0058] Medium corrosion resistance: prepare 10% sodium hydroxide aqueous solution, 10% sulfuric acid aqueous solution, 20% sodium chloride aqueous solution and 50% ethanol aqueous solution, take the film sample and immerse it in the corrosion solution at room temperature for 24 h, repeat the immersion and washing three times and dry;

[0059] Aging corrosion resistance: place the sample in an ultraviolet aging oven, control the temperature at 60℃, use a 50W ultraviolet lamp to irradiate, and the aging time is 168h;

[0060] According to GB / T1040.1-2018 standard, the tensile test of the sample before and after corrosion is carried out, the change rate of tensile strength Δh and the change rate of elongation at break Δs are used to characterize the corrosion resistance of the sample, and the specific test results are shown in the following table:

[0061]

[0062] Note: "-" means performance decline.

[0063] From the test results of the above table, it can be seen that the film material prepared by the application has good resistance to common acid, alkali and salt media and ultraviolet aging corrosion, wherein the medium corrosion resistance of example 1 is more excellent, and the ultraviolet aging corrosion resistance of examples 2-4 is better.

[0064] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The above is only an example and description of the application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the invention or exceed the scope defined by the claims.

Claims

1. A corrosion-resistant alternative to PVC film, characterized in that, The product comprises, by weight: 100 parts PET resin, 3.2-4.5 parts silicone corrosion resistant agent, 0.3-0.5 parts slip agent, 0.15-0.2 parts nucleating agent, and 4-6 parts filler; The organosilicon corrosion resistant agent is prepared by the following method: Step A1: Premix the terminal epoxy silicone oil and acetone, heat to 55-65℃, stir and slowly add N-methyldiethanolamine to react for 3-4.5h, and remove acetone by volatilization under reduced pressure after the reaction is completed to obtain the organosilicon matrix; Step A2: Mix the organosilicon matrix, tetramethylpiperidineamine, triphenylphosphine and dimethylacetamide, purge with nitrogen for protection, heat to 80-95℃, stir and react for 1.5-2 hours. After the reaction is complete, wash with water and separate the liquid to remove the aqueous phase and dry under vacuum to obtain the functionalized intermediate. Step A3: Mix the functionalized intermediate, monoethyl oxaloyl chloride, tetraethyl titanate and anhydrous toluene, purge with dry nitrogen, and heat to 45-60℃ under stirring for 2-3 hours. Then reduce the pressure to 1 kPa and continue heating to 75-90℃ for 1.2-1.5 hours. After the reaction is complete, remove the toluene by rotary evaporation to obtain the organosilicon corrosion resistant agent.

2. The corrosion-resistant alternative to PVC film according to claim 1, characterized in that, The epoxy content of the terminal epoxy silicone oil and the ratio of N-methyldiethanolamine to acetone are 0.1 mol: 36-42 mmol: 40-55 mL.

3. The corrosion-resistant alternative to PVC film according to claim 2, characterized in that, The room temperature viscosity of the epoxy silicone oil should not exceed 50 mm. 2 / s.

4. The corrosion-resistant alternative to PVC film according to claim 2, characterized in that, The ratio of organosilicon matrix, tetramethylpiperidineamine, triphenylphosphine and dimethylacetamide is 100g: 8-12mL: 0.2-0.3g: 60-90mL.

5. The corrosion-resistant alternative to PVC film according to claim 4, characterized in that, The ratio of functionalized intermediate, monoethyl oxaloyl chloride, tetraethyl titanate and anhydrous toluene is 100g: 20-30mL: 0.12-0.16g: 50-70mL.

6. The corrosion-resistant alternative to PVC film according to claim 1, characterized in that, Stearamide was chosen as the slip agent.

7. The corrosion-resistant alternative to PVC film according to claim 1, characterized in that, The filler is oleophilic nano-silica.

8. A production process for a corrosion-resistant alternative to PVC film according to any one of claims 1-7, characterized in that, The process includes the following steps: Process S1: PET resin, silicone corrosion resistant agent, slip agent, nucleating agent and filler are mixed evenly by a high-speed mixer, then transferred to an internal mixer and mixed at 260°C until the torque is stable. The mixture is then discharged and pelletized to obtain composite masterbatch. Process S2: The composite masterbatch is melted and extruded into a casting, rolled to a fixed thickness to form a blank film, and then stretched and shaped to obtain a corrosion-resistant PVC replacement film.

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