PVC film with adsorption function and preparation method thereof

Abstract

The invention discloses a PVC (polyvinyl chloride) film with an adsorption function and a preparation method thereof, relates to the technical field of functional film preparation, and particularly relates to the PVC film with the adsorption function and the preparation method thereof. An adsorption function layer is constructed through modified silicon dioxide, a PVC film is endowed with an adsorption function through corona treatment, a metal organic framework material has the characteristics of high specific surface area and a porous structure, and silicon dioxide is modified in a mode that the silicon dioxide is coated with the metal organic framework material; a silane coupling agent is added into the adsorption functional layer, so that the interface defect is reduced, and the binding force between materials is enhanced; the plasticizer is added to improve the flexibility of the PVC film; the antistatic agent is added to reduce electrostatic resistance, and the ink layer is prevented from losing efficacy due to dust pollution after printing; through the synergistic effect of an adsorption function layer constructed by corona treatment and modified silicon dioxide, the adsorption capacity of the PVC film to printing ink is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of functional film preparation, and specifically to a PVC film with an adsorption function and a preparation method thereof. Background Art

[0002] The non-polar characteristics of the PVC film itself result in a low surface energy, insufficient adsorption, and difficulty for the ink to effectively wet and penetrate. This causes the ink to easily peel off after printing, especially during friction or folding, resulting in blurred or faded patterns. A film with poor adsorption cannot quickly absorb the solvent in the ink, prolongs the drying time, and increases the probability of backside offset.

[0003] The adsorption of the PVC film directly affects the printing pressure and ink volume control. A film with moderate adsorption can reduce the fluctuation of the printing pressure, avoid too thick or too thin ink layers, and thus improve the overprint accuracy; a PVC film with good adsorption can firmly fix the ink, reduce the ink layer peeling caused by friction during use, better resist solvent penetration, avoid the ink being eroded by chemicals, and prolong the lifespan of the printed matter.

[0004] Therefore, we propose a PVC film with an adsorption function and a preparation method thereof. Summary of the Invention

[0005] The purpose of the present invention is to provide a PVC film with an adsorption function and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A preparation method of a PVC film with an adsorption function includes the following processes:

[0008] Step 1: Mix concentrated sulfuric acid and hydrogen peroxide solution to obtain a piranha solution, add silicon dioxide, and heat for reaction to obtain pretreated silicon dioxide;

[0009] Step 2: Mix benzimidazole and zinc nitrate in deionized water, add dimethylformamide, add the pretreated silicon dioxide for dispersion, seal, and heat for reaction to obtain modified silicon dioxide;

[0010] Step 3: Mix an aqueous acrylic resin, a silane coupling agent, the modified silicon dioxide, and an additive to obtain an adsorption function layer coating;

[0011] Step 4: Take the adsorption function layer coating obtained in Step 3, coat it on the surface of the PVC base film, and dry it to form an adsorption function layer, thereby obtaining a PVC film with an adsorption function.

[0012] Further, the process of Step 1 is as follows:

[0013] Silica was added to the piranha solution and heat-treated at 80-90 °C for 20-30 min. The lower-layer white dispersion was taken, centrifuged, washed, and vacuum dried to obtain pretreated silica.

[0014] Further, the piranha solution was prepared by mixing concentrated sulfuric acid and hydrogen peroxide solution. The concentration of concentrated sulfuric acid was 37-38%, the concentration of hydrogen peroxide was 30%-45%, and the volume ratio of concentrated sulfuric acid to hydrogen peroxide solution was (7-5):3.

[0015] Further, the mass ratio of silica to the piranha solution was 1:(5-6).

[0016] Further, in step one, the process conditions for centrifugation were: rotation speed 8200-8600 r / min, time 3-5 min; the process conditions for vacuum drying were: vacuum drying at 60-70 °C for 2-3 h.

[0017] Further, the process of step two was as follows:

[0018] Benzimidazole and zinc nitrate (Zn(NO3)2·6H2O) were mixed in deionized water, a dimethylformamide (DMF) solution was added, and the mixture was added to a reaction kettle. Pretreated silica was added, dispersed, and stirred thoroughly for 3-4 h. After the reaction kettle was sealed, it was placed in a programmable muffle furnace, the temperature was set to 80-120 °C, and it was kept warm for 48-72 h. After the reaction ended, it was left to stand for 12-15 h. The lower-layer white dispersion was taken, centrifuged, washed with acetone, and vacuum dried to obtain modified silica.

[0019] Further, in step two, the mass ratio of benzimidazole, zinc nitrate, dimethylformamide, pretreated silica, and deionized water was (3-4):1:2:2:1.

[0020] Further, in step two, the process conditions for centrifugation were: rotation speed 6200-6600 r / min, time 20-25 min; the process conditions for vacuum drying were: vacuum drying at 60-70 °C for 3-4 h.

[0021] In the above technical solution, first, through the heat treatment of silica, a layer of hydroxyl groups was modified on the substrate surface, which was convenient for the coordination of the Zn-MOFs material. The terminal coordination functional groups (hydroxyl or carboxyl) could coordinate with the metal nodes on the Zn-MOFs, so as to ensure that the Zn-MOF material was firmly embedded on the substrate surface. By coating the silica with the metal-organic framework material, the supplementary material for the adsorption pores was increased, preventing the dragging and embedding in the printing ink, and achieving the purpose of increasing the adsorption effect.

[0022] During the solvothermal synthesis of Zn-MOFs, unreacted zinc nitrate or benzimidazole may remain, and the high solubility of acetone can effectively remove these impurities.

[0023] Furthermore, the process of Step 3 is as follows:

[0024] Grind, heat, and stir evenly aqueous acrylic resin, silane coupling agent, modified silica, and cosolvent, and then cool to obtain the coating for the adsorption functional layer.

[0025] Furthermore, in Step 3, the mass components of the coating for the adsorption functional layer are: 30 - 50 parts of aqueous acrylic resin, 1 - 1.5 parts of silane coupling agent, 5 - 10 parts of modified silica, and 5 - 10 parts of additives.

[0026] Furthermore, in Step 3, the mass components of the additives include: 0.5 - 2 parts of plasticizer, 0.05 - 1 part of defoamer, 0.05 - 1 part of lubricant, 5 - 10 parts of antistatic agent, 2 - 3 parts of heat stabilizer, and 15 - 30 parts of distilled water.

[0027] Furthermore, in Step 3, the silane coupling agent is KH-570, the heating temperature is 40 - 60 °C, the grinding time is 15 - 20 min, and it is cooled to room temperature.

[0028] Furthermore, the plasticizer is trioctyl trimellitate (TOTM), the defoamer is polyether-modified silicone (DT-650), the lubricant is calcium stearate, the antistatic agent is sodium dodecylbenzenesulfonate, and the heat stabilizer is organotin (mercapto tin).

[0029] In the above technical solution, the present invention constructs a metal-organic framework by doping with Zn element. Compared with Fe or Al, Zn element has good chemical properties and thermal stability, is colorless, and the Zn-O bond is not easily hydrolyzed; the microporous structure of Zn-MOF can adsorb ink solvents, and the surface MOFs layer adsorbs ink molecules through uniform pores, preventing the back of the printed matter from smudging, and has good printing applicability.

[0030] By adding a plasticizer, the flexibility of the PVC film is improved without affecting the thermal stability; adding an antistatic agent: reducing electrostatic adsorption of dust and ensuring printing quality. The present invention enhances the contact area and wettability between the filler and the organic material by adding a silane coupling agent, and further strengthens the adhesion and dispersibility between the two.

[0031] Furthermore, the surface of the PVC base film is corona-treated.

[0032] Furthermore, the process conditions of the corona treatment are: the corona power is 30 - 50 kW, the time is 20 - 30 min, and the oxygen flow rate is 10 - 15 L / min.

[0033] In the above technical solution, through the corona treatment of the surface of the PVC base film, oxygen in the air is highly ionized to generate ozone, activating the surface of the PVC base film, generating arc discharge, forming polar groups, increasing the molecular polarity, raising the surface tension, generating invisible micropores, roughening the surface, and enhancing the adsorption of ink.

[0034] For the PVC base film after corona treatment, the microscopic concave points formed by the roughening of its surface increase the contact area of the coating. The Zn-MOFs material particles are physically anchored and embedded in the surface pores, reducing the risk of coating peeling.

[0035] Through the synergistic effect of the metal-organic framework material and the polar surface, the high specific surface area and porous structure of Zn-MOFs provide adsorption sites to capture ink molecules. The highly polar surface of the base film after corona treatment accelerates the ink penetration through capillary action, and the pores of Zn-MOFs lock the solvent molecules to avoid back smudging.

[0036] Furthermore, in step four, the coating thickness of the adsorption functional layer of the PVC base film is 2 - 3 μm, and the thickness of the PVC base film is 0.1 - 3 mm.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. The PVC film with adsorption function of the present invention endows the PVC film with adsorption function by constructing an adsorptive adsorption functional layer.

[0039] 2. For the PVC film with adsorption function of the present invention, the rigid framework of Zn-MOFs can improve the mechanical strength of the PVC matrix. By modifying silica, the Zn-MOFs material is coated on the surface of silica as a supplementary material to increase the adsorption pores, preventing the dragging and embedding of printing ink, and achieving the purpose of increasing the adsorption effect.

[0040] 3. The PVC film with adsorption function of the present invention, through the corona treatment of the PVC film, uses a high-frequency high-voltage electric field to increase the content of surface hydroxyl and carboxyl groups. The highly polar surface of the base film after corona treatment accelerates the ink penetration through capillary action, and the pores of the modified silica lock the solvent molecules to increase the adsorption capacity.

[0041] 4. The PVC film with adsorption function of the present invention, through the synergistic effect of the surface treatment and filler optimization of the PVC film, enables the PVC film to have adsorption ability while improving the ink permeability and improving the problem of back sticking of printed products. Specific embodiments

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] In the following specific embodiments:

[0044] The following "parts" are parts by mass;

[0045] The following "piranha solution" is prepared by mixing concentrated sulfuric acid and hydrogen peroxide solution. The concentration of concentrated sulfuric acid is 37%, the concentration of hydrogen peroxide is 30%, and the volume ratio of concentrated sulfuric acid to hydrogen peroxide solution is 7:3;

[0046] Silica, model TH-2000, sourced from Shandong Wanhua Tianhe New Materials Co., Ltd.;

[0047] Waterborne acrylic resin, model SGR-1335, sourced from Guangzhou Changhao Trading Co., Ltd.;

[0048] PVC base film: thickness 3 mm, sourced from Dongguan Lingmei New Materials Co., Ltd.

[0049] Example 1: A preparation method of a PVC film with adsorption function, comprising the following steps:

[0050] Step 1: Add silica to the piranha solution, heat-treat at 80 °C for 20 min, take the lower-layer white dispersion, centrifuge at 8200 r / min for 3 min, wash with deionized water, and vacuum-dry at 60 °C for 2 h to obtain pretreated silica; the mass ratio of silica to the piranha solution is 1:5;

[0051] Step 2: Mix 30 parts of benzimidazole and 10 parts of zinc nitrate (Zn(NO3)2·6H2O) in 10 parts of deionized water, add 20 parts of dimethylformamide (DMF) solution, add to a reaction kettle, add 20 parts of pretreated silica, disperse, stir well for 3 h, seal the reaction kettle and place it in a programmable muffle furnace, set the temperature to 80 °C, keep warm for 48 h, after the reaction is completed, let it stand for 12 h, take the lower-layer white dispersion, centrifuge at 6200 r / min for 20 min, wash with acetone, and vacuum-dry at 60 °C for 3 h to obtain modified silica;

[0052] Step 3: Grind 30 parts of waterborne acrylic resin, 1 part of silane coupling agent, 5 parts of modified silica, and 5 parts of additives, heat, stir evenly, and cool to obtain the coating for the adsorption functional layer; the mass components of the additives include: 0.5 part of plasticizer, 0.05 part of defoamer, 0.05 part of lubricant, 5 parts of antistatic agent, 2 parts of heat stabilizer, and 15 parts of distilled water; the heating temperature is 40 °C, the grinding time is 15 min, and it is cooled to room temperature.

[0053] Step 4: Take the coating for the adsorption functional layer obtained in Step 3, coat it on the surface of the PVC base film obtained in Step 3, and dry it to obtain a PVC film with an adsorption function; the coating thickness of the adsorption functional layer is 2 μm; the surface of the PVC base film is corona-treated; the parameters of the corona treatment are: the corona power is 30 kW, the time is 20 min, and the oxygen flow rate is 10 L / min.

[0054] Example 2

[0055] A preparation method of a PVC film with an adsorption function, comprising the following steps:

[0056] Step 1: Add silica to the piranha solution, perform heat treatment at 85 °C for 25 min, take the lower white dispersion liquid, centrifuge at 8400 r / min for 4 min, wash with deionized water, and vacuum dry at 65 °C for 2.5 h to obtain pretreated silica; the mass ratio of silica to the piranha solution is 1:5.5.

[0057] Step 2: Mix 35 parts of benzimidazole and 10 parts of zinc nitrate (Zn(NO3)₂·6H₂O) in 10 parts of deionized water, add 20 parts of dimethylformamide (DMF) solution, add it to a reaction kettle, add 20 parts of pretreated silica, disperse, and stir thoroughly for 3.5 h. After sealing the reaction kettle, place it in a programmable muffle furnace, set the temperature to 85 °C, keep it warm for 56 h. After the reaction is completed, let it stand for 15 h, take the lower white dispersion liquid, centrifuge at 6500 r / min for 23 min, wash with acetone, and vacuum dry at 65 °C for 3.5 h to obtain modified silica.

[0058] Step 3: Grind 40 parts of waterborne acrylic resin, 1.2 parts of silane coupling agent, 7 parts of modified silica, and 7 parts of additives, heat, stir evenly, and cool to obtain the coating for the adsorption functional layer; the mass components of the additives include: 1.5 parts of plasticizer, 0.07 part of defoamer, 0.07 part of lubricant, 7 parts of antistatic agent, 2.5 parts of heat stabilizer, and 17 parts of distilled water; the silane coupling agent is KH-570, the heating temperature is 50 °C, the grinding time is 17 min, and it is cooled to room temperature.

[0059] Step 4: Take the coating of the adsorption functional layer obtained in Step 3, coat it on the surface of the PVC base film obtained in Step 3, and dry it to obtain a PVC film with adsorption function; the coating thickness of the adsorption functional layer is 2.5 μm; the surface of the PVC base film is corona-treated; the parameters of the corona treatment are: corona power is 40 kW, time is 25 min, and oxygen flow rate is 12 L / min.

[0060] Example 3

[0061] A preparation method of a PVC film with adsorption function includes the following steps:

[0062] Step 1: Add silica to the piranha solution, heat-treat it at 90 °C for 30 min, take the lower-layer white dispersion, centrifuge it at 8600 r / min for 5 min, wash it with deionized water, and vacuum-dry it at 70 °C for 3 h to obtain pretreated silica; the mass ratio of silica to the piranha solution is 1:6;

[0063] Step 2: Mix 40 parts of benzimidazole and 10 parts of zinc nitrate (Zn(NO3)2·6H2O) in 10 parts of deionized water, add 20 parts of dimethylformamide (DMF) solution, add them to a reaction kettle, add 20 parts of pretreated silica, disperse, and stir well for 4 h. After sealing the reaction kettle, put it into a programmable muffle furnace, set the temperature to 120 °C, keep it warm for 72 h. After the reaction is completed, let it stand for 15 h, take the lower-layer white dispersion, centrifuge it at 6600 r / min for 25 min, wash it with acetone, and vacuum-dry it at 60 °C for 4 h to obtain modified silica;

[0064] Step 3: Grind 50 parts of waterborne acrylic resin, 1.5 parts of silane coupling agent, 10 parts of modified silica, and 10 parts of additives, heat, stir evenly, and cool to obtain the coating of the adsorption functional layer; the mass components of the additives include: 2 parts of plasticizer, 1 part of defoamer, 1 part of lubricant, 10 parts of antistatic agent, 3 parts of heat stabilizer, and 30 parts of distilled water; the silane coupling agent is KH-570, the heating temperature is 60 °C, the grinding time is 20 min, and it is cooled to room temperature;

[0065] Step 4: Take the coating of the adsorption functional layer obtained in Step 3, coat it on the surface of the PVC base film obtained in Step 3, and dry it to obtain a PVC film with adsorption function; the coating thickness of the adsorption functional layer is 3 μm; the surface of the PVC base film is corona-treated; the parameters of the corona treatment are: corona power is 50 kW, time is 30 min, and oxygen flow rate is 15 L / min.

[0066] Comparative Example 1

[0067] A preparation method of a PVC film with adsorption function includes the following process:

[0068] Step 1: Mix benzimidazole and zinc nitrate in deionized water, add dimethylformamide, add silica for dispersion, seal, and heat react to obtain modified silica; the mass ratio of benzimidazole, zinc nitrate, dimethylformamide, silica, and deionized water is 3:1:2:2:1;

[0069] Step 2: Mix 30 parts of waterborne acrylic resin, 1 part of silane coupling agent, 5 parts of modified silica, and 5 parts of additives to obtain the adsorption functional layer coating; the mass components of the additives include: 0.5 part of plasticizer, 0.05 part of defoamer, 0.05 part of lubricant, 5 parts of antistatic agent, 2 parts of heat stabilizer, and 15 parts of distilled water;

[0070] Step 3: Take the adsorption functional layer coating obtained in Step 2, coat it on the surface of the PVC base film, dry it to form an adsorption functional layer, and obtain a PVC film with adsorption function; the coating thickness of the adsorption functional layer is 2 μm; the surface of the PVC film is corona treated; the corona power is 30 kW, the time is 20 min, and the oxygen flow rate is 10 L / min.

[0071] Comparative Example 2

[0072] Step 1: Add silica to the piranha solution, heat-treat at 80 °C for 20 min, take the lower-layer white dispersion, centrifuge, wash, and vacuum dry to obtain pretreated silica; the mass ratio of silica to the piranha solution is 1:5;

[0073] Step 2: Mix 30 parts of waterborne acrylic resin, 1 part of silane coupling agent, 5 parts of pretreated silica, and 5 parts of additives to obtain the adsorption functional layer coating; the mass components of the additives include: 0.5 part of plasticizer, 0.05 part of defoamer, 0.05 part of lubricant, 5 parts of antistatic agent, 2 parts of heat stabilizer, and 15 parts of distilled water;

[0074] Step 3: Take the adsorption functional layer coating obtained in Step 2, coat it on the surface of the PVC base film, dry it to form an adsorption functional layer, and obtain a PVC film with adsorption function; the surface of the PVC film is corona treated; the corona power is 30 kW, the time is 20 min, and the oxygen flow rate is 10 L / min.

[0075] Comparative Example 3

[0076] A preparation method of a PVC film with adsorption function, comprising the following steps:

[0077] Step 1: Add silica to the piranha solution, heat-treat at 85 °C for 25 min, take the lower-layer white dispersion, centrifuge at 8400 r / min for 4 min, wash with deionized water, and vacuum dry at 65 °C for 2.5 h to obtain pretreated silica; the mass ratio of silica to the piranha solution is 1:5;

[0078] Step 2: Mix 35 parts of benzimidazole and 10 parts of zinc nitrate (Zn(NO3)2·6H2O) in deionized water, add 20 parts of dimethylformamide (DMF) solution, add them into a reaction kettle, add 20 parts of pretreated silica, disperse, and stir thoroughly for 3.5 h. After sealing the reaction kettle, place it in a programmable muffle furnace, set the temperature to 85 °C, keep it warm for 56 h. After the reaction is completed, let it stand for 15 h, take the lower-layer white dispersion liquid, centrifuge it at 6500 r / min for 23 min, wash it with acetone, and dry it in vacuum at 65 °C for 3.5 h to obtain modified silica;

[0079] Step 3: Grind 40 parts of waterborne acrylic resin, 1.2 parts of silane coupling agent, 7 parts of modified silica, and 7 parts of cosolvent, heat, stir evenly, and then cool to obtain the coating for the adsorption functional layer; The mass components of the additives include: 1.5 parts of plasticizer, 0.07 part of defoamer, 0.07 part of lubricant, 7 parts of antistatic agent, 2.5 parts of heat stabilizer, and 17 parts of distilled water; The silane coupling agent is KH-570, the heating temperature is 50 °C, the grinding time is 17 min, and it is cooled to room temperature;

[0080] Step 4: Take the coating for the adsorption functional layer obtained in Step 3, coat it on the surface of the PVC base film obtained in Step 3, and dry it to obtain the PVC film with adsorption function; The coating thickness of the adsorption functional layer is 2 μm; The surface of the PVC base film is wiped after being soaked in acetone for 10 min to obtain a clean PVC base film.

[0081] Comparative Example 4

[0082] A preparation method of a PVC film with adsorption function, comprising the following steps:

[0083] Step 1: Add silica into piranha solution, heat-treat it at 84 °C for 23 min, take the lower-layer white dispersion liquid, centrifuge it at 8300 r / min for 3.5 min, wash it with deionized water, and dry it in vacuum at 68 °C for 2.5 h to obtain pretreated silica; The mass ratio of silica to piranha solution is 1:5.5;

[0084] Step 2: Mix 35 parts of terephthalic acid and 10 parts of aluminum hydroxide in deionized water, add 20 parts of dimethylformamide (DMF) solution, add them into a reaction kettle, add 20 parts of pretreated silica, disperse, and stir thoroughly for 3.5 h. After sealing the reaction kettle, place it in a programmable muffle furnace, set the temperature to 85 °C, keep it warm for 55 h. After the reaction is completed, let it stand for 14 h, take the lower-layer white dispersion liquid, centrifuge it at 6400 r / min for 20 min, wash it with acetone, and dry it in vacuum at 68 °C for 3.5 h to obtain modified silica;

[0085] Step 3: Grind, heat, and stir evenly 40 parts of waterborne acrylic resin, 1.2 parts of silane coupling agent, 7 parts of modified silica, and 7 parts of additives, and then cool to obtain the coating for the adsorption functional layer. The mass components of the additives include: 1.5 parts of plasticizer, 0.07 part of defoamer, 0.07 part of lubricant, 7 parts of antistatic agent, 2.5 parts of heat stabilizer, and 17 parts of distilled water. The silane coupling agent is KH-570. The heating temperature is 50 °C, the grinding time is 18 min, and it is cooled to room temperature.

[0086] Step 4: Take the coating for the adsorption functional layer obtained in Step 3, coat it on the surface of the PVC base film obtained in Step 3, and dry it to obtain a PVC film with an adsorption function. The coating thickness of the adsorption functional layer is 2 μm. The surface of the PVC base film is treated by corona. The corona power is 30 kW, the time is 20 min, and the oxygen flow rate is 10 L / min.

[0087] Experiment: Take the PVC films with adsorption functions obtained in Examples 1-3 and Comparative Examples 1-4 to prepare specimens, and detect their properties and record the test results respectively:

[0088] Ink adhesion performance test: Refer to the standard T / GMPA 11-2022, cut the transparent tape into appropriate lengths, seal it on the surface of the film after printing and drying, slowly peel off the tape in the first half and quickly peel off the tape in the second half, and observe the amount of ink transferred to the tape to infer how strong the ink adsorption force is. The ink is GS-03, sourced from Zhangzhou Green Spring Technology Co., Ltd.

[0089] Adhesion experiment: Refer to the standard IOS2409:2007, place the printed matter flat on a flat hard tabletop, and scratch it with a sharp needle. As long as the ink and the PVC film are in a completely adhered state, the ink surface will not fall off due to scratching.

[0090] Surface tension test: Refer to the standard T / GMPA 11-2022, use a mechanical tension tester and apply the platinum plate method to test the surface tension of the PVC film.

[0091] Tensile test: Conduct the test according to the standard GB / T 1040.2, use a universal material testing machine to test the axial tensile force, and test its tensile strength.

[0092] Performance comparison table

[0093]

[0094] According to the data in the above table, the following conclusions can be clearly obtained:

[0095] The PVC films with adsorption functions obtained in Examples 1-3 are compared with the PVC films with adsorption properties obtained in Comparative Examples 1-4. From the test results, it can be seen that

[0096] Compared with the comparative examples, the PVC films with adsorption function obtained in Examples 1-3 have high coloring power, high adhesion grade, high surface tension and high tensile strength.

[0097] Compared with Example 1, the PVC film using silica as an adsorption filler obtained in Comparative Example 1 has lower coloring power, surface tension and tensile strength than those in Example 1, and the adhesion grade is lower than that in Example 1. It can be seen that although the PVC film prepared by using untreated silica as an adsorption material and adding Zn-MOFs has good coloring property, it does not have the strong coloring performance, high adhesion grade and good printing anti-tacky effect of the PVC film prepared by using pretreated silica added with Zn-MOFs.

[0098] Compared with Example 1, the PVC film using pretreated silica as an adsorption material obtained in Comparative Example 2 has lower coloring power, surface tension and tensile strength than those in Example 1, and the adhesion grade is low. It can be seen that although the PVC film prepared by using pretreated silica has good adsorption performance, its surface tension is small, its wettability is poor, it is easy to adsorb impurities and dust, and it is easy to shorten the service life of printed products, and it does not have the good effect of the PVC film using modified silica as an adsorption material in the present invention.

[0099] Compared with Example 1, in Comparative Example 3, the PVC base film is not subjected to corona surface treatment, and acetone immersion cleaning is used to replace the surface treatment process. The PVC film prepared by using modified silica has lower coloring power, surface tension and tensile strength than those in Example 1, indicating that adding modified silica alone cannot endow the PVC film with good adsorption performance, and the synergistic effect of corona treatment on the surface of the PVC base film is required.

[0100] Compared with Example 1, in Comparative Example 4, the metal-organic framework material doped with Al element is used, and the coloring power, surface tension and tensile strength are smaller than those in Example 1, and the adhesion grade is higher than those in Comparative Examples 1-3. It can be seen that the PVC film using Al-MOFs as an adsorption material does not have the good effect of using Zn-MOFs as an adsorption material in the present invention.

[0101] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention.

Claims

1. A preparation method of a PVC membrane with adsorption function, characterized in that: It includes the following processes: Step 1: Mix concentrated sulfuric acid and hydrogen peroxide solution to obtain a piranha solution, add silicon dioxide, and heat for reaction to obtain pretreated silicon dioxide; Step 2: Mix benzimidazole and zinc nitrate in deionized water, add dimethylformamide, add pretreated silicon dioxide for dispersion, seal, and heat for reaction to obtain modified silicon dioxide; Step 3: Mix waterborne acrylic resin, silane coupling agent, modified silicon dioxide, and additives to obtain an adsorption functional layer coating; Step 4: Take the adsorption functional layer coating obtained in Step 3, coat it on the surface of the PVC base film, dry it, and form an adsorption functional layer to obtain a PVC film with adsorption function.

2. The preparation method of a PVC membrane with adsorption function according to claim 1, characterized in that: In Step 1, the process conditions for the heating reaction are: the heating temperature is 80 - 90 °C, and the time is 20 - 30 min.

3. The preparation method of a PVC membrane with an adsorption function according to claim 1, characterized in that: In Step 2, the process conditions for the heating reaction are: the heating temperature is 80 - 120 °C, and keep warm for 48 - 72 h.

4. The preparation method of a PVC film with an adsorption function according to claim 1, characterized in that: The mass ratio of the benzimidazole, zinc nitrate, dimethylformamide, pretreated silicon dioxide, and deionized water is (3 - 4):1:2:2:

1.

5. The preparation method of a PVC membrane with adsorption function according to claim 1, characterized in that: The mass ratio of the silicon dioxide to the piranha solution is 1:(5 - 6).

6. The preparation method of a PVC membrane with an adsorption function according to claim 1, characterized in that: The adsorption functional layer coating includes the following mass components: 30 - 50 parts of waterborne acrylic resin, 1.0 - 1.5 parts of silane coupling agent, 5 - 10 parts of modified silicon dioxide, and 5 - 10 parts of additives.

7. The preparation method of a PVC membrane with adsorption function according to claim 1, characterized in that: The surface of the PVC base film is corona-treated.

8. The preparation method of a PVC membrane with an adsorption function according to claim 6, characterized in that: The additives include the following mass components: 0.5 - 2 parts of plasticizer, 0.05 - 1 part of defoamer, 0.05 - 1 part of lubricant, 5 - 10 parts of antistatic agent, 2 - 3 parts of heat stabilizer, and 15 - 30 parts of distilled water.

9. The preparation method of a PVC membrane with adsorption function according to claim 1, wherein: The coating thickness of the adsorption functional layer coating is 2 - 3 μm, and the thickness of the PVC base film is 0.1 - 3 mm.

10. A PVC membrane with an adsorption function, characterized in that: Prepared according to the preparation method described in any one of claims 1 - 9.

Images