A method for preparing a textured protective film

Abstract

The application discloses a preparation method of a textured protective film, and the textured protective film comprises a polyester film base material and a silicone glue water coating layer coated on at least one surface of the base material, and the preparation method comprises the following steps: S1, a surface of the polyester film base material is scanned by using plasma to obtain a pretreated base material; S2, after the surface of the pretreated base material is uniformly coated with a silane coupling agent and dried, a transition layer is formed; S3, the silicone glue water is coated on the transition layer to form a main coating layer; S4, the main coating layer is pre-pressed by using a pre-pressing roller, then the main coating layer is pre-cured, and then the main coating layer is pressed by using a textured roller to obtain a textured film; and S5, the textured film is sent into an infrared hot air composite tunnel furnace to be cured in multiple stages, so that the textured protective film is obtained. The heat resistance and mechanical properties of the textured protective film are improved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a method for preparing a textured protective film. Background Technology

[0002] In the production, transportation, and storage of electronic devices and optical components, textured protective films serve to prevent scratches, contamination, and oxidation by covering the product surface. Traditional textured protective films use a polyethylene mesh plastic film as the base layer, combined with a cross-linked acrylic adhesive layer, which has the characteristics of preventing bubbles, leaving no adhesive residue, and being repeatedly peelable.

[0003] However, although existing textured protective films claim to be residue-free, the heat resistance of the polyethylene substrate and acrylic adhesive layer is actually poor (usually below 80°C). Under long-term adhesion or high-temperature environment, the adhesive layer is prone to cross-linking reaction or chemical migration, resulting in softening, deformation or residual adhesive stains. At the same time, the polyethylene substrate has poor puncture resistance and tensile strength, and may break due to external force during transportation or handling, resulting in protection failure. Summary of the Invention

[0004] This invention provides a method for preparing a textured protective film to solve the technical problems of poor heat resistance and mechanical properties of traditional textured protective films.

[0005] In a first aspect, the present invention provides a method for preparing a textured protective film, the textured protective film comprising a polyester film substrate and an organic silicone water coating coated on at least one side of the substrate, the preparation method comprising:

[0006] S1, Plasma scanning is used to scan the surface of the polyester film substrate to make the surface energy of the polyester film substrate 45dyn~55dyn, thus obtaining a pretreated substrate;

[0007] S2, uniformly coat the surface of the pretreated substrate with silane coupling agent and dry at 60℃~80℃ for 1min~3min to form a transition layer;

[0008] S3, apply silicone water to the transition layer to form the main coating layer;

[0009] S4. The main coating is pre-pressed by a pre-pressing roller at a pressure of 0.1MPa to 0.5MPa and a temperature of 40℃ to 60℃, and then pre-cured. The main coating is then embossed by a textured roller at a pressure of 0.8MPa to 1.5MPa and a temperature of 80℃ to 120℃ to obtain a textured film.

[0010] S5. The textured film is sent into an infrared hot air composite tunnel oven for multi-stage curing to obtain a textured protective film.

[0011] In some embodiments, the plasma power density in S1 is 0.5 W / cm².2 ~2.0W / cm 2 The scanning speed is 5m / min to 30m / min.

[0012] In some of these embodiments, in S2, the silane coupling agent is γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane dissolved in isopropanol solution at a concentration of 1 wt% to 5 wt%.

[0013] In some of these embodiments, the coating thickness in S3 is 5 μm to 15 μm.

[0014] In some embodiments, in step S3, the main coating is applied using an oscillating coating head, and the ratio between the oscillation frequency and the conveying rate of the pretreated substrate is 1:(5-10).

[0015] In some embodiments, the silicone water is a UV-curable silicone water and contains 0.1 wt% to 0.5 wt% graphene or fluorinated modified silicone.

[0016] In some embodiments, the pre-curing of the main coating in step S4 is performed using a wavelength of 365nm–385nm and a power of 50W / cm. 2 ~150W / cm 2 The UV-LED light source irradiates the main coating for 2 to 5 seconds.

[0017] In some embodiments, in step S4, the opening angle of the anilox roller is 110° to 130°.

[0018] In some embodiments, in S5, the multi-stage curing includes: circulating hot air at a temperature of 80°C to 100°C for 30 to 60 seconds; followed by curing with a wavelength of 2.5 μm to 4 μm and a power density of 2 W / cm². 2 ~5W / cm 2 Infrared radiation is applied, and simultaneously, hot air at a temperature of 120℃~150℃ is circulated for 3min~8min; then, hot air at a temperature of 60℃~80℃ and a wind speed of 0.3m / s~0.8m / s is used for cooling for 2min~5min.

[0019] Secondly, the present invention also provides a textured protective film, which is prepared based on the above-described method for preparing textured protective films.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The polyester film substrate used in this invention has excellent high-temperature resistance (withstanding temperatures above 120°C), solving the problems of softening, deformation, and residue in traditional polyethylene substrates during high-temperature processes. An organic silicone water coating combined with a silane coupling agent transition layer enhances adhesive adhesion and effectively reduces the risk of residue after high temperatures or long-term use. Plasma pretreatment optimizes the substrate surface energy, improving adhesive uniformity and adhesion, and reducing edge lifting. Pre-pressing, pre-curing, and embossing processes ensure stable embossed structures while maintaining the adhesive's ability to be repeatedly peeled off. Infrared hot air composite curing further strengthens the cross-linking density of the adhesive, giving the protective film higher mechanical strength and temperature resistance, making it suitable for protecting electronic devices in harsh environments. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] As used herein, the terms “prepared from” and “comprising” are synonymous. The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0024] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including the ranges “1 to 4”, “1 to 3”, “1 to 2”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0025] Furthermore, the indefinite articles “a” and “an” preceding the elements or components of this invention do not impose any limitation on the quantity requirement (i.e., the number of times) of the elements or components. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers to the singular form.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Example 1

[0028] A method for preparing a textured protective film, the textured protective film comprising a polyester film substrate (PET, 50 μm) and an organic silicone water coating coated on one side of the substrate, the method comprising:

[0029] S1, using plasma at 0.5W / cm 2 The surface of the polyester film substrate was scanned at 5 m / min to make the surface energy of the polyester film substrate 45 dyn, thus obtaining a pretreated substrate.

[0030] S2, uniformly coat the surface of the pretreated substrate with 1 wt% γ-aminopropyltriethoxysilane dissolved in isopropanol solution, and dry at 60°C for 3 min to form a transition layer;

[0031] S3 uses an oscillating coating head to coat a UV-curable silicone water containing 0.1 wt% graphene onto the transition layer with a coating thickness of 5 μm. The ratio between the oscillation frequency and the delivery rate of the pretreated substrate is 1:10, forming the main coating.

[0032] S4, after pre-pressing the main coating with a pre-pressure roller at 0.1MPa and 40℃, is applied at 365nm and 50W / cm. 2 The main coating is irradiated with a UV-LED light source for 5 seconds, and then the main coating is embossed with an anilox roller with a cell opening angle of 110° at 0.8MPa and 80℃ to obtain an anilox film.

[0033] S5, the textured film is fed into an infrared hot air composite tunnel oven and circulated with 80℃ hot air for 60s; then, it is circulated with 2.5μm, 2W / cm 2 Infrared radiation was applied, and simultaneously, hot air at 120°C was circulated for 8 minutes; then, hot air at 60°C and 0.8 m / s was used to cool the film for 2 minutes to obtain a textured protective film.

[0034] Example 2

[0035] A method for preparing a textured protective film, the textured protective film comprising a polyester film substrate (PET, 50 μm) and an organic silicone water coating layer coated on one side of the substrate, the method comprising:

[0036] S1, using plasma at 1.2W / cm 2The surface of the polyester film substrate was scanned at 15 m / min to make the surface energy of the polyester film substrate 50 dyn, thus obtaining a pretreated substrate.

[0037] S2, uniformly coat the surface of the pretreated substrate with 3 wt% γ-aminopropyltriethoxysilane dissolved in isopropanol solution, and dry at 70°C for 2 min to form a transition layer;

[0038] S3 uses an oscillating coating head to coat the transition layer with a UV-curable silicone water containing 0.3 wt% graphene, with a coating thickness of 10 μm. The ratio between the oscillation frequency and the conveying rate of the pretreated substrate is 1:8, forming the main coating.

[0039] S4, after pre-pressing the main coating with a pre-pressure roller at 0.3MPa and 50℃, is then coated with a coating at 375nm and 100W / cm. 2 The main coating is irradiated with a UV-LED light source for 3 seconds, and then the main coating is embossed with an anilox roller with a cell opening angle of 120° at 1.2MPa and 100℃ to obtain an anilox film.

[0040] S5, the textured film is fed into an infrared hot air composite tunnel oven and circulated with 90℃ hot air for 45 seconds; then, it is circulated with 3.5μm, 3W / cm 2 Infrared radiation was applied, and simultaneously, hot air at 135°C was circulated for 5 minutes; then, hot air at 70°C and 0.5 m / s was used to cool the film for 3 minutes to obtain a textured protective film.

[0041] Example 3

[0042] A method for preparing a textured protective film, the textured protective film comprising a polyester film substrate (PET, 50 μm) and an organic silicone water coating layer coated on one side of the substrate, the method comprising:

[0043] S1 uses plasma with a power density of 2.0 W / cm². 2 The surface of the polyester film substrate was scanned at a scanning speed of 30 m / min to make the surface energy of the polyester film substrate 55 dyn, thus obtaining a pretreated substrate.

[0044] S2, uniformly coat the surface of the pretreated substrate with 5 wt% γ-glycidyl etheroxypropyltrimethoxysilane dissolved in isopropanol solution, and dry at 80°C for 1 min to form a transition layer;

[0045] S3 uses an oscillating coating head to coat a UV-curable silicone water containing 0.5 wt% fluorinated modified silicone onto the transition layer, with a coating thickness of 15 μm. The ratio between the oscillation frequency and the conveying rate of the pretreated substrate is 1:5, forming the main coating.

[0046] S4, after pre-pressing the main coating with a pre-pressure roller at 0.5MPa and 60℃, is then coated with a coating at 385nm and 150W / cm. 2 The main coating is irradiated with a UV-LED light source for 2 seconds, and then the main coating is embossed with an anilox roller with a cell opening angle of 130° at 1.5MPa and 120℃ to obtain an anilox film.

[0047] S5, the textured film is fed into an infrared hot air composite tunnel oven and circulated with 100℃ hot air for 30 seconds; then, it is circulated with 4μm, 5W / cm 2 Infrared radiation was applied, and simultaneously, hot air at 150°C was circulated for 3 minutes; then, hot air at 80°C and 0.3 m / s was used to cool the film for 5 minutes to obtain a textured protective film.

[0048] Comparative Example 1

[0049] Compared with Example 1, Comparative Example 1 omits step S1.

[0050] Comparative Example 2

[0051] Compared with Example 1, Comparative Example 2 omits step S2.

[0052] Comparative Example 3

[0053] Compared with Example 1, Comparative Example 3 uses the same concentration of dimethyl silicone oil instead of the silane coupling agent in step S3.

[0054] Comparative Example 4

[0055] Compared with Example 1, Comparative Example 4 uses a conventional fixed coating head instead of the oscillating coating head in step S3.

[0056] Comparative Example 5

[0057] Compared to Example 1, the UV-curable silicone water of Comparative Example 5 does not contain graphene or fluorinated modified silicone.

[0058] Comparative Example 6

[0059] Compared with Example 1, step S4 of Comparative Example 6 removes the step of pre-curing the main coating.

[0060] Comparative Example 7

[0061] Compared with Example 1, Comparative Example 7 uses 80°C hot air circulation for 10 minutes instead of the multi-stage curing step in step S5.

[0062] Comparative Example 8

[0063] Commercially available protective films with a textured surface, using polyethylene mesh plastic film as the base layer and cross-linked acrylic adhesive layer.

[0064] 1. Apply the protective film (25mm × 150mm) to a standard stainless steel material (surface roughness ≤ 0.1μm), and roll it back and forth three times with a 2kg rubber roller to remove air bubbles. After placing it at 120℃ for 24 hours, cool it to room temperature and measure the edge warping rate (warped edge length / total edge length × 100%). Peel the protective film at a peeling angle of 180° and a speed of 300mm / min, and record the peeling force-displacement curve throughout the process. Calculate the curve fluctuation rate to obtain the uniformity of peeling force. Use a precision electronic balance (accuracy 0.1μg) to measure the mass difference of the stainless steel plate before and after peeling, and calculate the residual adhesive rate (mass difference / protective film mass × 100%).

[0065] 2. Using a universal testing machine, stretch the protective film (25mm×150mm) at a speed of 50mm / min until it breaks, and record the maximum stress (MPa).

[0066] 3. Use a 1mm diameter steel needle to puncture the protective membrane at a speed of 100mm / min and record the maximum penetration force (N).

[0067] 4. Apply the protective film (25mm×150mm) to the standard stainless steel material, peel it off at a speed of 300mm / min and then reapply it. After 20 cycles, calculate the adhesion retention rate (adhesion force of the 20th cycle / initial adhesion force × 100%).

[0068] Table 1 Performance test results of Examples 1 to 3 and Comparative Examples 1 to 7

[0069]

[0070] As shown in Table 1 above, the overall performance of Examples 1 to 3 is significantly better than that of the comparative examples, indicating that the textured protective film prepared by the method of the present invention has significant advantages over traditional textured protective films. The significantly increased high-temperature warpage rate, decreased peel uniformity, and increased residual adhesive rate in Comparative Example 1 may be due to insufficient surface energy of the substrate caused by the lack of plasma treatment, resulting in weak physical / chemical bonding between the transition layer and the main coating and the substrate. Comparative Example 2 showed deteriorated high-temperature performance (warpage rate 3.8%, residual adhesive rate 0.6%) and reduced adhesion retention (75%). This is because the lack of a silane coupling agent transition layer (γ-aminopropyltriethoxysilane) resulted in a lack of chemical bridges in the direct bonding between the main coating and the substrate, leading to uneven interfacial stress transmission. The dimethyl silicone oil used in Comparative Example 3 is a non-reactive inert material and cannot form chemical bonds through hydrolysis and condensation like a silane coupling agent, resulting in weak inter-coating bonding and decreased mechanical properties. Comparative Example 4 showed reduced peel uniformity, decreased puncture resistance, and decreased tensile strength, possibly due to the inability of the fixed coating head to disperse graphene through vibration, resulting in uneven filler distribution in the coating. Comparative Example 5 exhibited poor mechanical properties, high-temperature resistance, and repeated peel retention, possibly due to the lack of graphene reinforcement and the surface energy regulation function of fluorination modification. Comparative Example 6, lack of pre-pressing, resulted in insufficient coating density before UV curing, making it prone to microcracks during embossing, leading to the highest high-temperature warpage and the worst peel uniformity. Comparative Example 7 showed increased warpage and residual adhesive rate (0.9%), and decreased adhesion retention, possibly due to the inability of single hot air curing to achieve gradient cross-linking, resulting in insufficient stress release within the coating.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for preparing a textured protective film, characterized in that, The textured protective film comprises a polyester film substrate and an organic silicone water coating coated on at least one side of the substrate, the preparation method comprising: S1, Plasma scanning is used to scan the surface of the polyester film substrate to make the surface energy of the polyester film substrate 45 dyn~55 dyn, thus obtaining a pretreated substrate; S2, uniformly coat the surface of the pretreated substrate with silane coupling agent and dry at 60℃~80℃ for 1min~3min to form a transition layer; S3, apply silicone water to the transition layer to form the main coating layer; S4. The main coating is pre-pressed with a pre-pressing roller at a pressure of 0.1MPa~0.5MPa and a temperature of 40℃~60℃, and then pre-cured. The main coating is then embossed with an anilox roller at a pressure of 0.8MPa~1.5MPa and a temperature of 80℃~120℃ to obtain an anilox film. S5, the textured film is sent into an infrared hot air composite tunnel oven for multi-stage curing to obtain a textured protective film. In S2, the silane coupling agent is γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane dissolved in isopropanol solution at a concentration of 1 wt% to 5 wt%. In step S3, the silicone water is a UV-curable silicone water and contains 0.1 wt% to 0.5 wt% graphene or fluorinated modified silicone. In step S4, the main coating is pre-cured by irradiating it with a UV-LED light source with a wavelength of 365nm~385nm and a power density of 50 W / cm²~150W / cm² for 2s~5s. In step S5, multi-stage curing includes: The system circulates hot air at 80℃~100℃ for 30s~60s; then it radiates infrared radiation with a wavelength of 2.5μm~4μm and a power density of 2W / cm²~5W / cm², while simultaneously circulating hot air at 120℃~150℃ for 3min~8min; and finally cools the system with hot air at 60℃~80℃ and a wind speed of 0.3m / s~0.8m / s for 2min~5min.

2. The method for preparing the textured protective film according to claim 1, characterized in that, In S1, the plasma power density is 0.5 W / cm² to 2.0 W / cm², and the scanning speed is 5 m / min to 30 m / min.

3. The method for preparing the textured protective film according to claim 1, characterized in that, In S3, the coating thickness of the main coating is 5μm~15μm.

4. The method for preparing the textured protective film according to claim 1, characterized in that, In step S3, the main coating is applied using an oscillating coating head, and the ratio between the oscillation frequency and the conveying rate of the pretreated substrate is 1:(5~10).

5. The method for preparing the textured protective film according to claim 1, characterized in that, In step S4, the opening angle of the anilox roller is 110°~130°.

6. A textured protective film, characterized in that, It is prepared according to the preparation method of the textured protective film as described in any one of claims 1 to 5.

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