Antifouling antistatic polyester film, preparation method and application

Abstract

The invention belongs to the technical field of polyester films, and particularly relates to an antifouling and antistatic polyester film, a preparation method and application, the antifouling and antistatic polyester film comprises a polyester base material and an antifouling and antistatic coating, and the antifouling and antistatic coating is prepared from the following raw materials in parts by weight: 10-14 parts of modified waterborne acrylic resin; 17-25 parts of a conductive polymer; 0.6 to 1 part of a cross-linking agent; 0.1 to 0.3 part of a wetting agent; 60 to 75 parts of deionized water; the modified water-based acrylic resin is prepared from the following raw materials in parts by weight: 13 to 17 parts of cage type oligomeric silsesquioxane; 34-42 parts of a hard monomer; 30-38 parts of a soft monomer; 11 to 15 parts of a hydrophilic monomer; and 2-4 parts of an initiator. The polyhedral oligomeric silsesquioxane modified water-based acrylic resin can significantly improve the stain resistance of the film, and the prepared antistatic polyester film has the characteristics of good stain adhesion resistance and easy cleaning.

Description

Technical Field

[0001] This invention belongs to the field of polyester film technology, specifically relating to an antifouling and antistatic polyester film, its preparation method, and its application. Background Technology

[0002] Polyester film possesses excellent mechanical properties, chemical stability, and optical properties, leading to its widespread application in packaging, electronics, and optics. However, traditional polyester film surfaces are prone to accumulating dust and stains, affecting its performance and appearance. Furthermore, polyester film typically has high surface resistance, making it susceptible to static electricity, which can have adverse effects in static-sensitive applications, such as optical equipment.

[0003] To improve the antifouling and antistatic properties of polyester films, researchers have conducted extensive studies. For antifouling, a common approach is to coat the film surface with a low surface energy coating, such as a fluorine- or silicon-containing coating, to reduce stain adhesion. For antistatic properties, the surface resistance of the film can be reduced by adding conductive materials, such as metal powders, carbon nanotubes, and conductive polymers.

[0004] However, existing antifouling and antistatic coatings often suffer from unstable performance and poor adhesion to the substrate. Therefore, developing a polyester film with excellent antifouling and antistatic properties and strong adhesion to the substrate is of great significance. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an antifouling and antistatic polyester film, its preparation method and application; so as to solve the problem of poor antifouling and antistatic performance of existing polyester films.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An antifouling and antistatic polyester film, comprising a polyester substrate and an antifouling and antistatic coating, wherein the raw materials for preparing the antifouling and antistatic coating, by weight, include: 10-14 parts of modified waterborne acrylic resin; 17-25 parts of conductive polymer; 0.6-1 parts of crosslinking agent; 0.1-0.3 parts of wetting agent; and 60-75 parts of deionized water; wherein the raw materials for preparing the modified waterborne acrylic resin, by weight, include: 13-17 parts of cage-type oligomeric silsesquioxane; 34-42 parts of hard monomer; 30-38 parts of soft monomer; 11-15 parts of hydrophilic monomer; and 2-4 parts of initiator.

[0008] Furthermore, the cage-like oligomeric silsesquioxane is at least one of octaepoxypropyl cage-like oligomeric silsesquioxane and heptaisobutyl methacrylate cage-like oligomeric silsesquioxane.

[0009] Further, the hard monomer is at least one of methyl methacrylate, methyl acrylate, and ethyl methacrylate; the soft monomer is at least one of butyl acrylate, butyl methacrylate, and isooctyl acrylate.

[0010] Furthermore, the hydrophilic monomer is at least one of dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, and 2,2-dimethylolpropionic acid.

[0011] Furthermore, the initiator is at least one of azobisisobutyronitrile (AIBN) and benzoyl peroxide.

[0012] Furthermore, the conductive polymer is an aqueous dispersion of polythiophene, and the solid content of the aqueous dispersion of polythiophene is 1-2%.

[0013] Furthermore, the crosslinking agent is at least one of polymelamine resin and polyisocyanate resin.

[0014] Furthermore, the wetting agent is at least one of acetylenic diols and polyether silicones.

[0015] A method for preparing an antifouling and antistatic polyester film, characterized in that the preparation method includes the following steps:

[0016] S1. Thoroughly mix cage-type oligomeric silsesquioxane, hard monomer, soft monomer, hydrophilic monomer, and initiator to obtain a mixed solution; add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, keep warm, and continue the reaction for 3 hours.

[0017] S2. After the heat preservation is completed, the system temperature is reduced to 40℃. Then, a neutralizing agent is added during the stirring process and neutralized for 30 minutes. Finally, deionized water is added, stirred thoroughly and filtered to obtain cage-type oligomeric silsesquioxane modified waterborne acrylic resin.

[0018] S3. Add modified waterborne acrylic resin, conductive polymer, crosslinking agent, wetting agent, and deionized water to the container, and stir at high speed for 30 minutes to obtain an antistatic coating liquid; uniformly coat the prepared antistatic coating liquid onto the surface of the polyester film to obtain an antifouling and antistatic polyester film.

[0019] The above-described antifouling and antistatic polyester film is used as a protective material in optical equipment.

[0020] The beneficial effects of this invention are:

[0021] This invention has many significant beneficial effects, as detailed below:

[0022] 1. Regarding antistatic properties, the surface resistivity of the antifouling and antistatic polyester film prepared by this invention is 2.9 × 10⁻⁶.8 -6.0×10 8 The resistance is between Ω, achieving a good level of antistatic properties. This is due to the reasonable addition of conductive polymers (such as polythiophene aqueous dispersion) in the formulation, which can effectively reduce the surface resistance of the film and make it less prone to static electricity accumulation during use, thus meeting the needs of static-sensitive scenarios.

[0023] 2. In terms of optical performance, the initial haze of the film prepared by this invention is between 3.23% and 3.52%, which is low and stable. This indicates that the preparation method and raw material selection of this invention will not have an adverse effect on the optical transparency of the polyester film, and can maintain excellent optical performance, making it a potential application in fields with high requirements for optical performance, such as optical equipment.

[0024] 3. The films prepared by this invention exhibit minimal haze changes after stain resistance testing (all within 0.07%), and all stain resistance tests are passed, indicating that stains such as oil droplets and red ink can be easily wiped away without significant residue. This excellent performance stems from the unique preparation process of the modified waterborne acrylic resin, in which the introduction of cage-like oligomeric silsesquioxanes plays a crucial role. Compared with Comparative Example 1 without cage-like oligomeric silsesquioxanes and Comparative Example 2 using commercially available ordinary waterborne acrylic resin, the haze of both increased significantly to 9.78% and 11.54% respectively after stain resistance testing, failing the stain resistance test. This fully demonstrates that the waterborne acrylic resin modified with cage-like oligomeric silsesquioxanes in this invention can significantly improve the stain resistance of the film, giving the film surface excellent anti-stain adhesion and easy-to-clean properties. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the cross-sectional structure of the antifouling and antistatic polyester film in this invention.

[0027] The markings in the diagram represent: 1. Polyester substrate layer, 2. Anti-fouling and antistatic layer. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] An antifouling and antistatic polyester film includes the polyester substrate and an antifouling and antistatic coating, wherein the components of the antifouling and antistatic coating are as follows by weight:

[0030]

[0031] The components of the modified waterborne acrylic resin are as follows, by weight:

[0032]

[0033] The cage-like oligomeric silsesquioxane is at least one of octacyclooxypropyl cage-like oligomeric silsesquioxane and heptaisobutyl methacrylate cage-like oligomeric silsesquioxane. This cage-like oligomeric silsesquioxane possesses a unique cage-like structure; its symmetrical cubic structure and diverse organic groups effectively enhance the antifouling performance of acrylic resins as a modifier. The addition amount of this cage-like oligomeric silsesquioxane is 13-17 parts. When the addition amount is less than 13 parts, the antifouling performance of the resin is poor; when the addition amount is more than 17 parts, it will affect the stability of the resin polymerization process.

[0034] The hard monomer is selected from at least one of methyl methacrylate, methyl acrylate, and ethyl methacrylate. The hard monomer can enhance the cohesiveness of acrylic resin, thereby giving it certain physical properties such as strength and hardness.

[0035] The soft monomer is selected from at least one of butyl acrylate, butyl methacrylate, and isooctyl acrylate. The soft monomer can impart flexibility to the acrylic resin, which is beneficial for increasing the adhesion and tack of the film.

[0036] The hydrophilic monomer is selected from at least one of dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, and 2,2-dimethylolpropionic acid. The introduction of the hydrophilic monomer introduces functional groups, allowing it to react with the crosslinking agent and enhance adhesion to the substrate; furthermore, the introduction of the hydrophilic group improves hydrophilicity. The amount of hydrophilic monomer added is 11-15 parts. When the amount added is less than 11 parts, it will affect the water solubility of the polymer; when the amount added is more than 14 parts, more neutralizing agent will be required, leading to negative effects such as increased system viscosity and poor water resistance.

[0037] The initiator is selected from at least one of azobisisobutyronitrile and benzoyl peroxide.

[0038] The modified waterborne acrylic resin synthesis process is as follows: A cage-type oligomeric silsesquioxane, hard monomer, soft monomer, hydrophilic monomer, and initiator are thoroughly mixed to obtain a mixed solution. Ethylene glycol monobutyl ether solvent is added to a stirrer and heated to 80°C. The mixed solution is slowly added to the stirrer over 3 hours, kept at this temperature, and the reaction continues for another 3 hours. After the temperature is maintained, the system temperature is lowered to 40°C. A neutralizing agent is then added during stirring for 30 minutes to neutralize the mixture. Finally, deionized water is added, and the mixture is thoroughly stirred and filtered to obtain the modified waterborne acrylic resin.

[0039] The conductive polymer is an aqueous dispersion of polythiophene, selected from Changxing Chemical's G9013 and Zanli Technology's ZPD-Y010. This aqueous polythiophene dispersion is formed by dispersing polythiophene in water. Polythiophene itself is a conductive polymer with advantages such as stable antistatic properties and excellent optical properties. The antistatic coating solution of this invention incorporates polythiophene as the main raw material, and the resulting antistatic film exhibits good antistatic effects.

[0040] The crosslinking agent is selected from Zhanxin Company's CYMEL-385 and Bayer Company's BL XP2706.

[0041] The wetting agent is selected from Air Products' Surfynol 440 and Tego 270.

[0042] Example 1

[0043] Take 17 parts of octacyclooxypropyl cage-type oligomeric silsesquioxane, 38 parts of methyl methacrylate, 34 parts of butyl acrylate, 13 parts of dimethylaminoethyl methacrylate, and 3 parts of azobisisobutyronitrile, and mix thoroughly to obtain a mixed solution. Add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, maintain the temperature, and continue the reaction for another 3 hours; after the temperature maintenance, lower the system temperature to 40°C, then add triethylamine during stirring to adjust the pH to 8 and neutralize for 30 minutes. Finally, add 133 parts of deionized water, stir thoroughly until homogeneous, and filter to obtain the modified waterborne acrylic resin.

[0044] Take 12 parts of modified waterborne acrylic resin, 21 parts of G9013, 0.8 parts of CYMEL-385, 0.2 parts of Surfynol 440, and 60 parts of deionized water, and stir at high speed for 30 minutes to obtain an antistatic coating solution. Apply the prepared antistatic coating solution evenly to the surface of a polyester film to obtain the antifouling and antistatic polyester film. Performance test results are shown in Table 1.

[0045] Example 2

[0046] Take 13 parts of heptaisobutyl methacrylate cage-type oligomeric silsesquioxane, 20 parts of methyl methacrylate, 14 parts of methyl acrylate, 22 parts of butyl acrylate, 16 parts of butyl methacrylate, 6 parts of dimethylaminoethyl methacrylate, 5 parts of hydroxyethyl methacrylate, and 2 parts of benzoyl peroxide, and mix thoroughly to obtain a mixed solution. Add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, maintain the temperature, and continue the reaction for 3 hours; after the temperature maintenance, lower the system temperature to 40°C, then add triethylamine during stirring to adjust the pH to 8 and neutralize for 30 minutes. Finally, add 129 parts of deionized water, stir thoroughly until homogeneous, and filter to obtain the modified waterborne acrylic resin.

[0047] Take 10 parts of modified waterborne acrylic resin, 23 parts of ZPD-Y010, 0.6 parts of BL XP2706, 0.1 parts of Tego 270, and 50 parts of deionized water, and stir at high speed for 30 minutes to obtain an antistatic coating solution. Apply the prepared antistatic coating solution evenly to the surface of a polyester film to obtain the antifouling and antistatic polyester film. Performance test results are shown in Table 1.

[0048] Example 3

[0049] Take 10 parts of octacyclooxypropyl cage-type oligomeric silsesquioxane, 7 parts of heptaisobutyl cage-type oligomeric silsesquioxane POS, 28 parts of methyl acrylate, 24 parts of ethyl methacrylate, 16 parts of butyl methacrylate, 14 parts of isooctyl acrylate, 10 parts of hydroxyethyl methacrylate, 5 parts of 2,2-dimethylolpropionic acid, and 4 parts of azobisisobutyronitrile, and mix thoroughly to obtain a mixed solution. Add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, maintain the temperature, and continue the reaction for 3 hours; after the temperature maintenance, lower the system temperature to 40°C, then add triethylamine during stirring to adjust the pH to 8 and neutralize for 30 minutes, finally add 137 parts of deionized water, stir thoroughly and filter to obtain the modified waterborne acrylic resin.

[0050] Take 14 parts of modified waterborne acrylic resin, 19 parts of G9013, 1 part of CYMEL-385, 0.3 parts of Tego270, and 75 parts of deionized water, and stir at high speed for 30 minutes to obtain an antistatic coating solution. Apply the prepared antistatic coating solution evenly to the surface of a polyester film to obtain the antifouling and antistatic polyester film. Performance test results are shown in Table 1.

[0051] Example 4

[0052] Take 14 parts of octacyclooxypropyl cage-type oligomeric silsesquioxane, 36 parts of methyl acrylate, 20 parts of butyl acrylate, 16 parts of isooctyl acrylate, 7 parts of dimethylaminoethyl methacrylate, 5 parts of 2,2-dimethylolpropionic acid, and 2.5 parts of benzoyl peroxide, and mix thoroughly to obtain a mixed solution. Add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, maintain the temperature, and continue the reaction for 3 hours; after the temperature maintenance, lower the system temperature to 40°C, then add triethylamine during stirring to adjust the pH to 8 and neutralize for 30 minutes. Finally, add 131 parts of deionized water, stir thoroughly until homogeneous, and filter to obtain the modified waterborne acrylic resin.

[0053] Take 11 parts of modified waterborne acrylic resin, 25 parts of ZPD-Y010, 0.7 parts of BL XP2706, 0.15 parts of Surfynol 440, and 55 parts of deionized water, and stir at high speed for 30 minutes to obtain an antistatic coating solution. Apply the prepared antistatic coating solution evenly to the surface of a polyester film to obtain the antifouling and antistatic polyester film. Performance test results are shown in Table 1.

[0054] Example 5

[0055] Take 16 parts of heptaisobutyl methacrylate cage-type oligomeric silsesquioxane, 22 parts of methyl methacrylate, 18 parts of ethyl methacrylate, 32 parts of soft monomer, 9 parts of hydroxyethyl methacrylate, 5 parts of 2,2-dimethylolpropionic acid, and 3.5 parts of azobisisobutyronitrile, and mix thoroughly to obtain a mixed solution. Add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, keep warm and continue the reaction for 3 hours; after the heat preservation is completed, lower the system temperature to 40°C, then add triethylamine during stirring to adjust the pH to 8 and neutralize for 30 minutes, finally add 135 parts of deionized water, stir thoroughly and filter to obtain the modified waterborne acrylic resin.

[0056] Take 13 parts modified waterborne acrylic resin, 17 parts G9013, 0.9 parts CYMEL-385, 0.25 parts Surfynol 440, and 65 parts deionized water, and stir at high speed for 30 minutes to obtain an antistatic coating solution. Apply the prepared antistatic coating solution evenly to the surface of a polyester film to obtain the antifouling and antistatic polyester film. Performance test results are shown in Table 1.

[0057] Comparative Example 1

[0058] Acrylic resin was modified without the addition of cage-type oligomeric silsesquioxanes, and other conditions were the same as in Example 1. The performance test results are shown in Table 1.

[0059] Comparative Example 2

[0060] Commercially available waterborne acrylic resin XK-14 (a product of Covestro) was used, and other conditions were the same as in Example 1. The performance test results are shown in Table 1.

[0061] The test results of the antifouling and antistatic polyester film are shown in Table 1. The test methods for each performance item in the table are as follows:

[0062] Surface resistance testing: Refer to ASTM D2578, instrument: SIMCO ST-4 surface resistance tester. Optical performance testing: Refer to GB / T 2410-2008.

[0063] Stain resistance test: Cut the prepared film into 10*10cm pieces, drop 3 drops of oil and 3 drops of red ink in parallel on each piece, wipe with a lint-free cloth, test the haze and observe whether there are any stains left.

[0064] Table 1. Performance test results of antifouling and antistatic polyester films prepared in Examples 1-5 and Comparative Examples 1-2

[0065]

[0066] As can be seen from the table, combining the test results of Examples 1-5 and Comparative Examples 1-2, the following experimental conclusions can be drawn:

[0067] In terms of surface resistivity, the antifouling and antistatic polyester films prepared in Examples 1-5 have a surface resistivity of 2.9 × 10⁻⁶. 8 -6.0×10 8 Between Ω, Comparative Example 1 is 5.6 × 10 8 Ω, Comparative Example 2 is 6.1 × 10 8 The surface resistivity of each embodiment and the comparative example is on the same order of magnitude, indicating that the addition of cage-type oligomeric silsesquioxane and the modified waterborne acrylic resin prepared by this invention are not significantly different from other cases in terms of basic antistatic properties.

[0068] Regarding optical performance, the haze of Examples 1-5 was between 3.23% and 3.52%, while the haze of Comparative Example 1 was 3.34% and that of Comparative Example 2 was 3.51%. The initial haze values ​​of each example were close, indicating that the formulation and preparation method of the present invention will not have an adverse effect on the optical performance of the polyester film and can maintain good optical transparency.

[0069] Stain resistance is a key advantage of this invention. In Examples 1-5, the haze change after the stain resistance test was minimal, all within 0.07%, and the stain resistance test pass rate was OK, indicating that oil droplets and red ink on the film surface could be effectively wiped away without significant residue, demonstrating excellent stain resistance. In contrast, Comparative Example 1 showed a significant increase in haze to 9.78% after the stain resistance test, and Comparative Example 2 even reached 11.54%, with both failing the stain resistance test. This fully demonstrates the important role of the cage-like oligomeric silsesquioxane-modified waterborne acrylic resin in improving the stain resistance of the film. Comparative Example 1, lacking cage-like oligomeric silsesquioxane, and Comparative Example 2, using commercially available ordinary waterborne acrylic resin, could not impart the same level of stain resistance as the modified resin of this invention. This further proves the unique advantages of the modified waterborne acrylic resin in this invention, and the key effect of cage-like oligomeric silsesquioxane in improving the anti-fouling performance of polyester films.

[0070] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A stain-resistant and antistatic polyester film, the stain-resistant and antistatic polyester film comprising a polyester substrate and a stain-resistant and antistatic coating, characterized in that, The raw materials for preparing the antifouling and antistatic coating, by weight, include: 10-14 parts of modified waterborne acrylic resin; 17-25 parts of conductive polymer; 0.6-1 part of crosslinking agent; 0.1-0.3 parts of wetting agent; and 60-75 parts of deionized water. The raw materials for preparing the modified waterborne acrylic resin, by weight, include: 13-17 parts of cage-type oligomeric silsesquioxane; 34-42 parts of hard monomer; 30-38 parts of soft monomer; 11-15 parts of hydrophilic monomer; and 2-4 parts of initiator.

2. The antifouling and antistatic polyester film according to claim 1, characterized in that, The cage-type oligomeric silsesquioxane is at least one of octaepoxypropyl cage-type oligomeric silsesquioxane and heptaisobutyl methacrylate cage-type oligomeric silsesquioxane.

3. The antifouling and antistatic polyester film according to claim 1, characterized in that, The hard monomer is at least one of methyl methacrylate, methyl acrylate, and ethyl methacrylate; the soft monomer is at least one of butyl acrylate, butyl methacrylate, and isooctyl acrylate.

4. The antifouling and antistatic polyester film according to claim 1, characterized in that, The hydrophilic monomer is at least one of dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, and 2,2-dimethylolpropionic acid.

5. The antifouling and antistatic polyester film according to claim 1, characterized in that, The initiator is at least one of azobisisobutyronitrile and benzoyl peroxide.

6. The antifouling and antistatic polyester film according to claim 1, characterized in that, The conductive polymer is an aqueous dispersion of polythiophene, and the solid content of the aqueous dispersion of polythiophene is 1-2%.

7. The antifouling and antistatic polyester film according to claim 1, characterized in that, The crosslinking agent is at least one of polymelamine resin and polyisocyanate resin.

8. The antifouling and antistatic polyester film according to claim 1, characterized in that, The wetting agent is at least one of acetylenic diols and polyether silicones.

9. A method for preparing an antifouling and antistatic polyester film as described in any one of claims 1 to 8, characterized in that, The preparation method includes the following steps: S1. Thoroughly mix cage-type oligomeric silsesquioxane, hard monomer, soft monomer, hydrophilic monomer, and initiator to obtain a mixed solution; add ethylene glycol monobutyl ether solvent to a stirrer and heat to 80°C; slowly add the mixed solution to the stirrer over 3 hours, keep warm, and continue the reaction for 3 hours. S2. After the heat preservation is completed, the system temperature is reduced to 40℃. Then, a neutralizing agent is added during the stirring process and neutralized for 30 minutes. Finally, deionized water is added, stirred thoroughly and filtered to obtain cage-type oligomeric silsesquioxane modified waterborne acrylic resin. S3. Add modified waterborne acrylic resin, conductive polymer, crosslinking agent, wetting agent, and deionized water to the container, and stir at high speed for 30 minutes to obtain an antistatic coating liquid; uniformly coat the prepared antistatic coating liquid onto the surface of the polyester film to obtain an antifouling and antistatic polyester film.

10. The application of the antifouling and antistatic polyester film as described in any one of claims 1 to 8 as a protective material in optical equipment.

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