Method for improving adhesive force of magnetron sputtering coating on surface of organic glass

Abstract

The invention provides a method for improving the adhesive force of a magnetron sputtering coating on the surface of organic glass, and belongs to the technical field of repairing and manufacturing of aviation transparent parts, and the method comprises the following steps: cleaning the organic glass, preparing a transition layer solution, spraying the transition layer solution on the cleaned surface of the organic glass, and curing to obtain the organic glass. And after curing, carrying out magnetron sputtering coating on the organic glass. According to the method, a specific transition layer is adopted to improve the adhesive force of an organic glass coating film, a set of transition layer raw materials suitable for an organic glass substrate is selected, and the formula of the transition layer and the technological process for preparing the transition layer are determined. According to the method, the adhesive force can be effectively improved, the light transmittance of the magnetron sputtering film layer is hardly influenced, the integrity and continuity of the film layer can be kept in a severe environment, operation is convenient and fast, the requirement for equipment is low, raw materials are easy to obtain, the quality of the transition layer is stable, and the method is suitable for mass production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of repairing and manufacturing of aviation transparent parts, and particularly relates to a method for improving the adhesion of a magnetron sputtering film on the surface of organic glass. BACKGROUND

[0002] The organic glass in the cockpit of an airplane is usually provided with a transparent conductive film plated by a surface magnetron sputtering method to control the reflection and transmission of incident electromagnetic waves, so as to achieve the effect of electromagnetic wave shielding, reduce the damage and threat of an electromagnetic pulse field to the electronic information system and electronic equipment in the airplane, improve the survivability of the airplane, and ensure the execution of the airplane. However, since the substrate of the organic glass (PMMA) belongs to a high-molecular organic material, and the composition of the transparent conductive film is usually metal or metal oxide, the chemical bond formed between the two is weak, the interface bonding capacity is poor, and the thermal deformation temperature of the organic glass is relatively low (generally < 120 DEG C), so that only normal-temperature or low-temperature plating can be adopted. The activity of film-forming atoms is limited, and the nucleation density is low in the case of plating by the magnetron sputtering method at normal temperature or low temperature, which leads to poor adhesion, and slight scratching or adhesion can damage the integrity of the film layer, and even cause large-scale peeling of the film layer, and complete failure of the shielding performance. Moreover, since the organic glass is a flexible substrate, and the transparent conductive film has a large difference in elastic modulus, water absorption, and the like, the film layer is prone to cracking, losing continuity, and leading to a decrease in the shielding performance under the environment of high humidity, salt spray, and temperature alternation.

[0003] A method for preparing an aluminum film with high adhesion by the magnetron sputtering method is disclosed in Chinese Patent Publication No. CN106521440A, which solves the problems of poor adhesion, high scrap rate, and inability to mass production of the magnetron sputtering plating of a metal film (mainly an aluminum film) on the surface of a flexible polymer material, but the deposition of a metal buffer layer on the surface of the substrate in the method is not applicable to the organic glass substrate, and the metal layer also has the problems of weak chemical bond and poor interface bonding capacity when being deposited by the magnetron sputtering method at normal temperature. SUMMARY

[0004] The application aims to solve the technical problems of poor adhesion, easy peeling, and poor interface bonding capacity of the organic glass plated by the magnetron sputtering method, and provides a method for improving the adhesion of a magnetron sputtering film on the surface of organic glass.

[0005] To achieve the above-mentioned purpose, the technical solution provided by the application is as follows:

[0006] A method for improving the adhesion of a magnetron sputtering film on the surface of organic glass is provided, which comprises the following steps:

[0007] Step 1, cleaning the organic glass substrate to remove surface stains;

[0008] Step 2: Prepare the transition layer solution: Mix hydroxyacrylic resin with biuret to obtain component A, mix butyl acetate with propylene glycol methyl ether acetate to obtain component B, then mix component A and component B and stir evenly to obtain a transition layer solution with a viscosity of 10~15s.

[0009] Step 3: Apply the transition layer solution to the cleaned acrylic glass surface and let it stand;

[0010] Step 4: Curing treatment of the coated plexiglass, heating the transition layer to 60±2℃ at a rate not exceeding 1℃ / min, holding it at that temperature for 5 hours, and then allowing it to cool naturally.

[0011] Step 5: Perform magnetron sputtering coating on the surface of the cured transition layer at room temperature.

[0012] Furthermore, in step 2, hydroxyl acrylic resin and biuret in component A are mixed at a mass ratio of 5:1; butyl acetate and propylene glycol methyl ether acetate in component B are mixed at a mass ratio of (97~100):81; and component A and component B are mixed at a mass ratio of 10:(31~33).

[0013] Furthermore, in step 1, the specific operation of cleaning the acrylic substrate is as follows: first, remove the dust from the surface of the acrylic substrate, then clean it with a neutral cleaning solution, and finally rinse it with deionized water and dry it in an environment with a cleanliness level of not less than 10,000.

[0014] Furthermore, the neutral cleaning aqueous solution is one of a neutral soap solution with a concentration of 3-5% or a neutral cleaning agent with a concentration of 5-20%.

[0015] Furthermore, after removing dust from the surface of the acrylic substrate and before cleaning with a neutral cleaning solution, you can use a cleaning cotton ball soaked in 120# gasoline to wipe away the oil and residual adhesive on the surface of the acrylic substrate, and then wipe away the residual gasoline.

[0016] Furthermore, in step 2, the ambient temperature for preparing the transition layer solution is 17~30℃, the humidity is 20~60%, and the environmental cleanliness is not lower than Class 1000.

[0017] Furthermore, in step 2, the transition layer solution, after preparation, needs to be filtered through medium-speed qualitative filter paper and allowed to stand until the bubbles completely disappear.

[0018] Furthermore, in step 3, the operating environment for the coating process is consistent with the preparation environment of the transition layer solution, and the acrylic substrate is at an angle of 30~40° to the horizontal plane during the coating process.

[0019] Furthermore, in step 3, the settling time is 1 hour, and the environmental cleanliness level is not lower than Class 100.

[0020] Furthermore, in step 5, the material of the magnetron sputtering coating is ITO, and the sheet resistance of the film is 10Ω / □.

[0021] The advantages of this invention are:

[0022] 1. The present invention sets a relatively loose organic transition layer between the plexiglass substrate and the transparent conductive film, so that the main components of the transparent conductive film, metal / metal oxide, can be effectively embedded in the transition layer during the magnetron sputtering process. This transforms the weak chemical bond between the metal / metal oxide and the organic material into a stronger mechanical bond and a stronger chemical bond between the same organic material, effectively improving the adhesion of the magnetron sputtered film under room temperature conditions.

[0023] 2. By adding a transition layer between the plexiglass substrate and the transparent conductive film, the present invention effectively reduces the difference in the coefficient of thermal expansion between the transparent conductive film and the plexiglass substrate, avoids the possibility of film failure and peeling when the temperature changes, and enables the transparent conductive film on the surface of the transition layer to maintain the integrity and continuity of the film layer under harsh conditions such as high temperature, low temperature, and temperature alternation.

[0024] 3. This invention sets a relatively loose organic transition layer between the plexiglass substrate and the transparent conductive film, changing the adhesion state of the transparent conductive film from a very shallow diffusion adhesion with a small effective adhesion area to a mechanical interlocking with a large effective adhesion area and a deep embedding degree. This significantly reduces the gap between the transparent conductive film and the plexiglass substrate, forming a denser structure. This effectively prevents the entry of small molecules such as water vapor, inorganic salts, and even mold, and can maintain the integrity and continuity of the film layer in harsh environments such as high humidity, salt spray, and mold.

[0025] 4. The raw materials used in the transition layer formulation are all common chemicals, the process is simple with fewer steps, the transition layer has high quality stability, and it is suitable for mass production. Detailed Implementation

[0026] The present invention will now be described in detail with the aid of exemplary embodiments thereof. It should be noted that the following detailed description of the present invention is for illustrative purposes only and is not intended to limit the scope of the invention.

[0027] This embodiment addresses the problems of poor interfacial performance during magnetron sputtering coating of plexiglass surfaces and difficulties in ensuring film integrity and easy detachment during use. It provides a method to improve the adhesion of magnetron sputtered films by adding a transition layer to the plexiglass surface. This method employs a specific transition layer formulation and a matching curing process to prepare the transition layer, effectively improving the adhesion of the magnetron sputtered film, maintaining film integrity, and having almost no impact on the film's optical properties. The raw materials used in this transition layer formulation are all common chemicals, the process is simple and involves few steps, and the transition layer exhibits high quality stability, making it suitable for mass production.

[0028] Example 1

[0029] The following tests were conducted using No. 3 directional aviation acrylic glass (YB-DM-3) with dimensions of 100mm×100mm×3mm;

[0030] Step 1: First, rinse the surface of the acrylic glass with 40℃ warm water. Then, use degreased cotton soaked in 120# gasoline to clean the acrylic glass. After cleaning, quickly wipe the surface of the acrylic glass with lint-free paper to remove any residual gasoline. Add 50g of neutral detergent (e.g., White Cat brand dishwashing liquid) to 1000ml of warm water to make a 5% neutral detergent solution. Use degreased cotton soaked in the solution to clean the acrylic glass. Finally, rinse the surface of the acrylic glass with deionized water. Place the acrylic glass in an oven and heat it to 60℃ at a rate of 1℃ / min for 2 hours, then cool it with the oven. In this embodiment, rinsing the surface of the acrylic glass with 40℃ warm water is used to achieve the effect of dust removal. In other embodiments, rinsing with 40~50℃ warm water can be used, or a hair dryer, electrostatic precipitator, or other dust removal tools can be used to remove dust from the surface of the acrylic glass. When wiping away residual gasoline, a soft cloth or other cleaning tools can also be used.

[0031] Step 2: In a Class 1000 cleanroom with an ambient temperature of 22℃ and humidity of 38%, and good exhaust function, operators wearing respirators are to perform the operation. Weigh 50g of water-based hydroxyl acrylic resin using an electronic balance and a beaker, then add 10g of biuret and stir at medium speed for 10 minutes on a multi-functional stirrer to obtain component A. Weigh 110g of butyl acetate in an empty beaker, then add 90g of propylene glycol methyl ether acetate and stir at medium speed for 20 minutes on a multi-functional stirrer to obtain component B. Weigh 50g of component A in an empty beaker, then add 160g of component B and stir at medium speed for 30 minutes on a multi-functional stirrer to obtain the transition layer solution. Measure the viscosity of the solution using a Forte 4 cup viscometer; the viscosity is 12s.

[0032] In a Class 1000 cleanroom, at an ambient temperature of 22℃ and humidity of 38%, a round, medium-speed qualitative filter paper was folded into four layers and placed in a funnel, with the edge of the filter paper slightly below the edge of the funnel. The filter paper was moistened with water to ensure it adhered tightly to the inner wall of the funnel, thus removing air bubbles. The neck of the funnel was placed against the inner wall of an empty beaker. The transition layer solution was then poured into the funnel along a stirring rod, which should point towards the third layer of filter paper. The liquid level in the funnel was less than two-thirds the height of the filter paper. After filtration, the transition layer solution was allowed to stand to remove air bubbles. Real-time observation showed that the air bubbles had completely disappeared after 5 minutes. The transition layer solution was then transferred along a clean stirring rod to a long-spouted glass pitcher and allowed to stand again. Observation showed that no air bubbles were present in the pitcher after 5 minutes.

[0033] Step 3: In a Class 1000 cleanroom, at an ambient temperature of 22℃ and humidity of 38%, remove the acrylic glass from the oven and place it on a coating rack at a 30° angle to the horizontal. Use an electrostatic dust removal gun to blow the glass from top to bottom, checking to ensure the coating surface is free of stains and impurities. Use a long-nozzle glass container to slowly and evenly apply the transition layer solution from the upper edge of the acrylic glass along the contour line until the entire coating surface is covered. Wearing clean nitrile rubber gloves, hold the edge of the acrylic glass and wipe away excess solution from the bottom of the acrylic glass with lint-free paper to prevent local solution accumulation from affecting the magnetron sputtering coating quality. After coating, let it stand for 10 minutes and check the acrylic glass surface for bubbles and flow marks.

[0034] Step 4: Transfer the acrylic glass to a Class 100 laminar flow cart and place it at 26°C for 1 hour. Check the thickness and color uniformity of the transition layer solution on the acrylic glass surface, ensuring there are no bubbles, impurities, or flow marks. Remove the acrylic glass from the laminar flow cart and place it in a clean oven. Heat it to 60°C at a rate of 1°C / min and hold for 5 hours. Then, allow it to cool naturally to 23°C before removing it from the oven.

[0035] Step 5: Perform magnetron sputtering coating on the surface of the cured transition layer at room temperature. Transfer the removed acrylic glass to the magnetron sputtering coating machine and perform the magnetron sputtering coating process for the transparent conductive film. The film material is indium tin oxide (ITO), the coating temperature is room temperature (i.e., the heating system is not started), and the film resistance is 10Ω / □.

[0036] The coated acrylic glass was inspected for light transmittance, haze, reflectivity, and color recognition. Following environmental tests according to GJB150.3A, GJB150.4A, GJB150.5A, GJB150.9A, GJB150.10A, GJB150.11A, GJB150.7A, and GJB150.8A, the coating remained intact and unchanged. Furthermore, according to clause 4.6.6 of GJB2485A, a 2cm wide adhesive tape with a peel strength of not less than 2.74 N / cm was firmly adhered to the coating surface and quickly pulled vertically. The coated acrylic glass showed no peeling or cracking.

[0037] Example 2

[0038] It is basically the same as Example 1, except that:

[0039] In step 1, first rinse the surface of the acrylic glass with 50℃ warm water. Add 30g of neutral detergent to 1000ml of warm water to make a 3% neutral cleaning solution.

[0040] In step 2, the ambient temperature was 17℃ and the humidity was 60%. 97g of butyl acetate was weighed in an empty beaker, and 81g of propylene glycol methyl ether acetate was added. The mixture was then stirred at medium speed for 20 minutes on a multi-functional stirrer to obtain component B. 10g of component A was weighed in an empty beaker, and 31g of component B was added. The mixture was then stirred at medium speed for 30 minutes on a multi-functional stirrer to obtain the transition layer solution. The viscosity of the solution was measured to be 10s using a Forte-4 cup viscometer.

[0041] In step 3, during the coating process, the acrylic glass is at a 40° angle to the horizontal plane.

[0042] Example 3

[0043] It is basically the same as Example 1, except that:

[0044] In step 1, first rinse the acrylic glass surface with 50℃ warm water. Add 30g of neutral soap to 1000ml of warm water to make a 5% neutral soap solution, and use a cotton ball soaked in the solution to clean the acrylic glass surface.

[0045] In step 2, the ambient temperature was 30℃ and the humidity was 20%. 100g of butyl acetate was weighed in an empty beaker, and 81g of propylene glycol methyl ether acetate was added. The mixture was then stirred at medium speed for 20 minutes on a multi-functional stirrer to obtain component B. 10g of component A was weighed in an empty beaker, and 33g of component B was added. The mixture was then stirred at medium speed for 30 minutes on a multi-functional stirrer to obtain the transition layer solution. The viscosity of the solution was measured to be 15s using a Forte-4 cup viscometer.

[0046] In step 3, during the coating process, the acrylic glass is at a 30° angle to the horizontal plane.

[0047] The transmittance, haze, reflectance, and color recognition of the coated plexiglass obtained in Examples 2 and 3 were checked. The results were the same as those in Example 1, with the film layer intact and without any changes, delamination, or cracking.

[0048] Existing coated acrylic glass without a transition layer was subjected to the following operations, and its transmittance, haze, reflectance, and color recognition were tested according to GB / T2410 and GB / T5137.2. The optical properties of samples with and without a transition layer were almost indistinguishable: the ITO film on the sample without the transition layer cracked after 26 hours in a high-humidity environment (26°C, 95%), while the sample with the transition layer cracked according to GJB150.3A, GJB150.4A, and GJB150.5A. According to GJB150.9A, GJB150.10A, GJB150.11A, GJB150.7A, and GJB150.8A, the film layer must remain intact and unchanged after environmental tests such as high temperature and high humidity, low temperature and high humidity, temperature shock, salt spray test, and mold test. According to the requirements of Clause 4.6.6 in GJB2485A, for samples without a transition layer, a 2cm wide adhesive tape with a peel strength of not less than 2.74N / cm should be fully adhered to the surface of the film layer. After being pulled vertically and quickly, the film layer should completely peel off. Glass with a transition layer should not show any film peeling or cracking under the same operation.

[0049] This invention incorporates a loosely structured organic transition layer between an acrylic substrate and a transparent conductive film. This allows the main components of the transparent conductive film, metal / metal oxide, to be effectively embedded in the transition layer during magnetron sputtering. In this transition layer, the forces between the transition layer and the acrylic substrate are primarily strong chemical bonds between similar organic materials, while the forces between the transparent conductive film and the transition layer are primarily mechanical bonds. This transformation of the previously weak chemical bonds between the metal / metal oxide and the organic material into strong mechanical bonds and strong chemical bonds between similar organic materials effectively improves the adhesion of the magnetron sputtered film at room temperature. Furthermore, by adding a transition layer between the acrylic substrate and the transparent conductive film, the difference in thermal expansion coefficients between the two is effectively reduced, preventing the film from failing and detaching due to temperature changes. This ensures that the transparent conductive film on the transition layer surface maintains its integrity and continuity even under harsh conditions such as high temperature, low temperature, and temperature alternation. Simultaneously, the adhesion state of the transparent conductive film is changed from a shallow diffusion adhesion with a small effective adhesion area to a mechanical interlocking adhesion with a large effective adhesion area and deep embedding. This significantly reduces the gaps between the transparent conductive film and the acrylic substrate, forming a denser structure. This effectively prevents the entry of small molecules such as moisture, inorganic salts, and even mold, maintaining the integrity and continuity of the film layer even in harsh environments such as high humidity, salt spray, and mold. Furthermore, the raw materials used in the transition layer formulation are all common chemicals, with fewer processes and simpler operation, resulting in high quality stability of the transition layer, making it suitable for mass production.

[0050] Finally, it should be noted that the features mentioned and / or shown in the above description of exemplary embodiments of the present invention can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered to be included within the scope of protection of the present invention.

Claims

1. A method for improving the adhesion of magnetron sputtered coatings on plexiglass surfaces, characterized in that, Includes the following steps: Step 1: Clean the acrylic substrate to remove surface stains; Step 2: Prepare the transition layer solution: Mix hydroxyacrylic resin with biuret to obtain component A, mix butyl acetate with propylene glycol methyl ether acetate to obtain component B, then mix component A and component B and stir evenly to obtain a transition layer solution with a viscosity of 10~15s. Step 3: Apply the transition layer solution to the cleaned acrylic glass surface and let it stand; Step 4: Curing treatment of the coated plexiglass, heating the transition layer to 60±2℃ at a rate not exceeding 1℃ / min, holding it at that temperature for 5 hours, and then allowing it to cool naturally. Step 5: Perform magnetron sputtering coating on the surface of the cured transition layer at room temperature.

2. The method according to claim 1, characterized in that, In step 2, hydroxyl acrylic resin and biuret in component A are mixed at a mass ratio of 5:1; butyl acetate and propylene glycol methyl ether acetate in component B are mixed at a mass ratio of (97~100):81; and component A and component B are mixed at a mass ratio of 10:(31~33).

3. The method according to claim 1, characterized in that, In step 1, the specific operation of cleaning the acrylic substrate is as follows: first, remove the dust from the surface of the acrylic substrate, then clean it with a neutral cleaning solution, and finally rinse it with deionized water and dry it in an environment with a cleanliness level of not less than 10,000.

4. The method according to claim 3, characterized in that, The neutral cleaning aqueous solution is either a neutral soap solution with a concentration of 3-5% or a neutral cleaning agent with a concentration of 5-20%.

5. The method according to claim 3, characterized in that, After removing dust from the surface of the acrylic substrate and before cleaning it with a neutral cleaning solution, you can use a cleaning cotton ball soaked in 120# gasoline to wipe away the oil and residual adhesive on the surface of the acrylic substrate, and then wipe away the residual gasoline.

6. The method according to claim 1, characterized in that, In step 2, the ambient temperature for preparing the transition layer solution is 17~30℃, the humidity is 20~60%, and the environmental cleanliness is not lower than Class 1000.

7. The method according to claim 1, characterized in that, In step 2, the transition layer solution, after preparation, needs to be filtered through medium-speed qualitative filter paper and allowed to stand until the bubbles completely disappear.

8. The method according to claim 6, characterized in that, In step 3, the operating environment for the coating process is the same as the preparation environment for the transition layer solution, and the acrylic substrate is at an angle of 30-40° to the horizontal plane during the coating process.

9. The method according to claim 1, characterized in that, In step 3, the settling time is 1 hour, and the environmental cleanliness level is not lower than Class 100.

10. The method according to claim 1, characterized in that, In step 5, the material of the magnetron sputtering coating is ITO, and the sheet resistance of the film is 10Ω / □.