TWI745679B - High-curve composite coating system forming method - Google Patents

Abstract

A method for forming a high-curve composite coating system. The steps include: (A) providing a metal structure substrate, and coating an attenuation layer on the surface of the metal structure substrate; (B) coating the surface of the attenuation layer An adapting layer; (C) coating a protective layer on the upper surface of the adapting layer. In this way, at least one flexible polymer coating material and a pre-dispersed particle composition with electromagnetic properties are used to cure and form on the surface of a high-curved structure through a chemical cross-linking reaction. This system can absorb and scatter the incident light in the environment. Microwave energy reduces the degree of reflection of microwave energy.

Description

High-curve composite coating system forming method

The present invention relates to a forming method of a composite coating system, in particular to a forming method of a high-curve composite coating system.

Megahertz (GHz) frequency range microwaves are widely used in wireless microwave communications, such as mobile phones, local area networks, microwave circuits and satellites. At the same time, the electromagnetic interference in the microwave environment is becoming increasingly severe, so it can reduce electromagnetic energy interference and reduce microwave background The demand for noise attenuating materials for microwaves has arisen at the historic moment, and the market demand has become increasingly urgent.

Generally, the traditional method of making microwave attenuating materials is to first disperse particles with electromagnetic properties evenly on rubber substrates such as Xinping rubber and silicone rubber, and then use metal molds to press the rubber to the desired thickness under high temperature and hot pressing. When using a film, the rubber film must be adhered to the surface of the metal structure piece by piece with a polymer adhesive. During the adhesion process, pressure must be continued until the adhesive is cured to ensure that the adhesive strength meets the requirements.

Usually aircraft, ships, vehicles and communication equipment and other vehicle structures are irregularly curved structures. During the adhesion process, the flat rubber film must be pressurized with a shaping mold, so that the film can adhere to the curved surface of the structure and bend and deform with the surface. Rubber film has certain rigidity and resilience, and strong local anisotropy It is difficult to predict the changes in stretching and elongation, the quality of on-site adhesion and local molding is not easy to control, the adhesion effect is not ideal, and it often leads to shortcomings such as residual prestress, film warpage and degumming. In addition, traditional microwave attenuation materials are mostly designed as a material with fixed electromagnetic characteristics, which cannot meet the requirements of microwave attenuation and microwave incident impedance adaptation at the same time, which greatly limits the efficiency of microwave attenuation.

Therefore, the industry currently needs a method for forming a high-curve composite coating system that can produce microwave attenuation coatings with good adhesion on irregular curved substrates, and at the same time take into account the requirements of microwave attenuation and microwave incident impedance adaptation, so as to prepare The high-curve composite coating required by the industry.

In view of the shortcomings of the above-mentioned conventional technology, the main purpose of the present invention is to provide a method for forming a composite coating, which can be cured and formed on the surface of a high-curvature metal structure through a chemical crosslinking reaction. The coating prepared by the present invention can absorb and Scatter the incident microwave energy in the environment and reduce the degree of reflection of microwave energy.

The coating prepared by the present invention is a multiple layer structure with different dielectric coefficients, different permeability coefficients, and specific thicknesses. Through electromagnetic impedance adaptation, electromagnetic/thermal energy conversion mechanism, it absorbs and scatters the incident microwave energy in the environment to improve The attenuation efficiency of incident microwave energy in a certain frequency range, and the degree of microwave attenuation in the selected wide-band frequency range can be adjusted by adjusting the type and quantity of additives contained in each layer of the composite coating system, and the thickness of each coating.

In order to achieve the above objective, according to one of the solutions of the present invention, a method for forming a high-curve composite coating system is provided. The steps include: (A) providing a metal structure substrate, and coating the surface of the metal structure substrate with a Attenuation layer, the dielectric coefficient of the attenuation layer is ε ₁ , and the permeability is μ ₁ ; (B) an adaptation layer is coated on the upper surface of the attenuation layer, and the dielectric coefficient of the adaptation layer is ε ₂ , The permeability coefficient is μ ₂ ; (C) A protective layer is coated on the upper surface of the adaptation layer, the dielectric coefficient of the protective layer is ε ₃ , and the permeability coefficient is μ ₃ . Among them, ε ₃ <ε ₁ <ε ₂ and μ ₃ <μ ₂ <μ ₁ .

The electromagnetic characteristic parameters of the above-mentioned layers can be as shown in Table 1, but not limited to this.

In the above, the thickness of the high-curvature composite coating system is less than 2 mm; the attenuation layer, the adapting layer or the protective layer can be formed by mixing a flexible polymer and an additive particle.

In the above, the flexible polymer is selected from one of the group consisting of polyurethane, epoxy-isocyanate and epoxy resin.

In the above, the additive particles of the attenuation layer are selected from one of the group consisting of carbon-based iron, ferrite, and cobalt-nickel alloy, and the addition ratio of the additive particles to the attenuation layer can be 60wt%-85wt %. The invention uses the attenuation layer coated on the metal structure substrate to convert the incoming electromagnetic energy into heat and reduce the reflection of electromagnetic energy.

In the above, the additive particles of the adapting layer are selected from one of the group consisting of carbon black, carbon fiber and silicon carbide, and the proportion of the additive particles added to the adapting layer can be 3wt%-12wt%. In the present invention, the electromagnetic impedance adapted to the incident microwave is provided by the adapting layer, so that the incident microwave can smoothly enter the attenuation layer of the composite coating system, and the reflection degree of the incident microwave energy is greatly reduced.

In the above, the additive particles of the protective layer are carbon black or titanium dioxide or other inorganic pigments, and the additive ratio of the additive particles to the protective layer can be 0.1wt%-10wt%. Through the protective layer coated on the surface of the adapting layer, the present invention reduces the damage degree of the composite coating system from the corrosion of environmental foreign objects, if necessary, and can cooperate with the adapting layer to further improve the electromagnetic impedance matching efficiency of microwave energy.

In the above, the molding method may be spray molding or casting molding.

In the above, the high-curve composite coating can be further cross-linked and cured. Among them, the cured and molded high-curvature composite coating can pass the 6mm diameter mandrel deflection test; the cured and molded high-curve composite coating can pass ASTM D3395 (standard test method for evaluating adhesion with blades) 5B grade coating system Adhesion test.

In the present invention, an elastic polymer coating material with high flexural properties including polyurethane, epoxy-isocyanate or epoxy resin is used as the bonding agent. Matrix, and additives with high dielectric coefficient and/or permeability, including: carbon black, carbon fiber, carbon-based iron, ferrite, silicon carbide, cobalt-nickel alloy, titanium dioxide and their composites, etc., with unique production The electromagnetic characteristics of microwave attenuating materials.

The microwave attenuating material composed of flexible elastic polymer coating material and particles with electromagnetic characteristics pre-dispersed therein can be cured and formed on the surface of a high-curved structure through a chemical cross-linking reaction. The attenuation layer coated on the metal structure substrate, the adapting layer coated on the attenuating layer, and the protective layer coated on the surface of the adapting layer. The division of labor in the multi-layer system is to play an addition of one plus one to greater than two. The effect is that the system can absorb and scatter the incident microwave energy in the environment, reduce the reflection degree of the microwave energy, have a higher degree of microwave attenuation in the selected wide band frequency range, and have a higher microwave reflection loss, and achieve high The composite coating on the surface of the curvature structure is formed at one time, with small prestress, no cracking, few process steps and high cost-effectiveness.

The above summary, the following detailed description and the accompanying drawings are all intended to further illustrate the methods, means and effects adopted by the present invention to achieve the intended purpose. The other objectives and advantages of the present invention will be described in the following description and drawings.

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20‧‧‧High Curve Composite Coating System

22‧‧‧High curved metal structure substrate

24‧‧‧Attenuation layer

26‧‧‧Adaptation layer

28‧‧‧Protection layer

The first figure is a flow chart of a method for forming a high-curve composite coating system according to the present invention; the second figure is a schematic diagram of the structure of a method for forming a high-curve composite coating system according to the present invention; The third figure is the adhesion test analysis diagram of the high-curve composite coating system of the embodiment of the present invention; the fourth diagram is the flexural characteristic test analysis diagram of the high-curve composite coating system of the embodiment of the present invention; the fifth diagram is The relationship between reflection loss and frequency of the high-curve composite coating system of the embodiment of the present invention.

The following is a specific example to illustrate the implementation of the present invention. Those familiar with the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification.

The present invention is a method for forming a high-curve composite coating system, which selects multiple layer structures with different dielectric coefficients, different permeability coefficients, and specific thicknesses, including a metal structure base material, an attenuation layer, an adaptation layer, and a protective layer It constitutes a high-curve composite coating system. Using a composite coating system composed of a highly flexible and elastic polymer coating material containing a composite with electromagnetic properties, it is cured and molded on the surface of a high curved structure through a chemical cross-linking reaction, so that it has both high microwave energy attenuation characteristics and a curved structure at one time. , The advantages of small prestress and no cracking.

The method for forming a high-curve composite coating system of the present invention includes: (A) providing a metal structure substrate, and coating an attenuation layer on the surface of the metal structure substrate; (B) on the attenuation layer The surface is coated with a matching layer; (C) a protective layer is coated on the surface of the matching layer. Please refer to the second figure, which is a schematic structural diagram of a method for forming a high-curve composite coating system of the present invention. As shown in the figure, the present invention The high-curved composite coating system 20 prepared by Ming Ming includes: a high-curved metal structure base material 22, an attenuation layer 24, a matching layer 26, and a protective layer 28.

In the above, the flexible polymer is selected from one of the group consisting of polyurethane, epoxy-isocyanate and epoxy resin; the additive particles of the attenuation layer 24 are selected from the group consisting of carbon-based One of the group consisting of iron, ferrite and cobalt-nickel alloy; the additive particles of the matching layer 26 are selected from one of the group consisting of carbon black, carbon fiber and silicon carbide; the protective layer 28 The additive particles are carbon black or titanium dioxide or other inorganic pigments.

Wherein, the molding method is spray molding or casting molding, and the high-curve composite coating can be further cross-linked and cured.

Example

Please refer to the first figure, which is a flow chart of the forming method of a high-curve composite coating system of the present invention. Coat a layer of attenuation material with a thickness of 0.9mm-1.5mm on the surface of the high-curved metal structure, which includes a flexible elastic polymer resin and pre-dispersed carbon-based iron, ferrite, cobalt-nickel alloy and its The additive of the mixture, this material has relatively high electromagnetic wave attenuation ability. Next, coat a layer of adaptable material with a thickness of 0.2mm-0.9mm on the attenuation material layer, which contains a flexible elastic polymer resin and pre-dispersed additives of carbon black, carbon fiber, graphite, silicon carbide and their mixtures. , This material has relatively low electromagnetic wave reflection ability. Finally, a protective material layer with a thickness of 0.02mm-0.08mm is coated on the adapting material layer, which contains a flexible elastic polymer resin and pre-dispersed coloring pigment additives. This material has relatively low electromagnetic wave reflection ability. The electromagnetic characteristic parameters of the above-mentioned layers are shown in Table 1.

In the above, the molding method may be spray molding or casting molding. An embodiment of the present invention can be: ^{spraying a proportioned epoxy resin/additive particle pre-dispersion solution on a 30×30cm 2} aluminum alloy plate, first spraying the attenuation layer to the required thickness, and then spraying the matching layer to the required thickness , And finally spray the protective layer to the required thickness, and then let it stand for 168 hours at room temperature 25°C, and wait for it to crosslink and solidify. Another embodiment of the present invention can be: on a 30×30cm ² aluminum alloy frame template, pouring the polyurethane/additive particle pre-dispersion that is prepared in proportion, first pouring the attenuation layer to the required thickness, and then pouring the appropriate Match the layer to the required thickness, and finally cast the protective layer to the required thickness, and then let it stand for 168 hours at room temperature 25°C, and wait for it to be cross-linked and cured.

Please refer to the third figure, which is the analysis diagram of the adhesion test of the high-curve composite coating system of the embodiment of the present invention. Grade 5B (the edges of the score line are extremely smooth and the coating of the square grid does not have any detachment) 0% peeling of the coating system. Please refer to the fourth figure, which is the flexural characteristic test analysis diagram of the high-flex composite coating system according to the embodiment of the present invention. The flexural characteristic test of the coating system is performed in accordance with the "Standard Test Method for Flexure" (ASTM D522), which is crimped by a 6mm mandrel The paint film of the coating system has no cracks.

The high-curve composite coating system of the present invention can be coated on the surface of the curved metal structure by spraying. The relationship between the reflection loss of microwave energy and the frequency is shown in the fifth figure, and the coating system of the present invention can be seen from the graph. At 10GHz The frequency of microwave reflection loss is more than -18dB. The best embodiment of the composite coating system in this case is to use epoxy resin as the polymer substrate, and the attenuation material layer (carbon-based iron contains 80% by weight) has a thickness of 1.3mm, which is suitable The thickness of the matching material layer (10% by weight of carbon black) is 0.3 mm, and the thickness of the protective material layer (0.5% by weight of titanium dioxide pigment) is 0.050 mm.

The invention adopts polyurethane, epoxy-isocyanate or epoxy resin with high flexibility and high physical properties as the coating material of the composite coating system, which is cured by chemical cross-linking reaction. On the surface of the high-curved metal structure, a combination of multiple layers with different dielectric coefficients, different permeability coefficients, and specific thicknesses is selected, including a metal structure base material, an attenuation layer, a matching layer, and a protective layer to form a high-curve composite coating The layer system, through the electromagnetic impedance adaptation, electromagnetic/thermal energy conversion mechanism, absorbs and scatters the incident microwave energy in the environment, improves the attenuation efficiency of the incident microwave energy in a certain frequency range, and can achieve the improvement of the construction and coating of the high-curved structure The mechanical performance of the system and the benefit of improving the microwave environment quality of the structure.

The composite coating system of the present invention can allow incident microwaves to easily enter the matching layer, minimize the reflection amount, and then be absorbed by the attenuation layer, thereby reducing the reflection amount of incident microwaves and increasing the reflection loss of the composite coating system. By adjusting the type and quantity of additive particles contained in each layer of the composite coating system, the degree of microwave attenuation in the selected wide-band frequency range is changed, so that the thickness of the coating system can be less than 2mm. The composite coating system has low microwave reflectivity, that is, high microwave reflection loss, and can be applied to high-tech products, microwave Communication equipment, aircraft, ships, vehicles and other transportation vehicles on the inner/outer surface of the structure and related products make it more widely used in the future.

The above-mentioned embodiments are merely illustrative to illustrate the features and effects of the present invention, and are not intended to limit the scope of the essential technical content of the present invention. Anyone familiar with this technique can modify and change the above-mentioned embodiments without departing from the spirit and scope of the invention. Therefore, the scope of protection of the rights of the present invention should be listed in the scope of patent application described later.

S101-S106‧‧‧Step

Claims (11)

A method for forming a high-curve composite coating system. The steps include: (A) providing a metal structure substrate, and coating an attenuation layer on the surface of the metal structure substrate. The dielectric coefficient of the attenuation layer is ε ₁ , conductive The magnetic coefficient is μ ₁ , where the surface of the metal structure substrate is non-plate-shaped; (B) an adaptation layer is coated on the upper surface of the attenuation layer, and the dielectric coefficient of the adaptation layer is ε ₂ , conductive The magnetic coefficient is μ ₂ ; (C) A protective layer is coated on the upper surface of the adapting layer, the dielectric coefficient of the protective layer is ε ₃ , and the magnetic permeability is μ ₃ ; where ε ₃ <ε ₁ <ε ₂ and μ ₃ <μ ₂ <μ ₁ , the thickness of the high-curvature composite coating system is less than 2 mm, and the attenuation layer, adapting layer or protective layer is formed by mixing a flexible polymer and an additive particle. The forming method of the high-curve composite coating system described in the first item of the scope of patent application, wherein the thickness of the attenuation layer is 0.9mm-1.5mm, the thickness of the adapting layer is 0.2mm-0.9mm, and the protective layer The thickness is 0.02mm-0.08mm. The method for forming a high-flex composite coating system as described in item 1 of the scope of the patent application, wherein the flexible polymer is selected from polyurethane, epoxy-isocyanate and epoxy resin One of the group. The forming method of the high-curve composite coating system as described in the first item of the patent application, wherein the additive particles of the attenuation layer are selected from the group consisting of carbon-based iron, ferrite and cobalt-nickel alloy one. The method for forming a high-curve composite coating system as described in the first item of the patent application, wherein the additive particles of the matching layer are selected from one of the group consisting of carbon black, carbon fiber and silicon carbide. The method for forming a high-curve composite coating system as described in item 1 of the scope of the patent application, wherein the additive particles of the protective layer are carbon black or titanium dioxide. The method for forming a high-curve composite coating system as described in any one of items 1 to 6 of the scope of the patent application, wherein the additive particle is added to the attenuation layer in a proportion of 60wt%-85% by weight, and the additive particle The addition ratio of the matching layer is 3wt%-12wt%, and the addition ratio of the additive particles to the protective layer is 0.1wt%-10wt%. The molding method of the high-curve composite coating system described in the first item of the scope of patent application, wherein the molding method is spray molding or casting molding. The method for forming a high-curve composite coating system as described in item 1 or item 8 of the scope of patent application, wherein the high-curve composite coating is further cross-linked and cured. The method for forming a high-curvature composite coating system as described in item 9 of the scope of the patent application, wherein the cured and formed high-curvature composite coating can pass a 6mm diameter mandrel deflection test. The molding method of the high-curve composite coating system as described in item 9 of the scope of patent application, wherein the cured and molded high-curve composite coating can pass ASTM D3395 (Standard Test Method for Evaluating Adhesion with Blades) 5B Grade Coating System adhesion test.

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