A roller coating device and a roller coating method and their application in preparing microwave absorbing coating

Abstract

The present invention discloses a roller coating device and a roller coating method and their application in preparing an absorbing coating. The roller coating device comprises a driving component, a roller shaft, a plate-like substrate, and a substrate fixing component; a coating portion is provided on part or all of the outer surface of the roller shaft; a non-rigid connection is adopted between the driving component and the roller shaft; the plate-like substrate is horizontally laid and fixed to the substrate fixing component; the roller shaft contacts the surface of the plate-like substrate to be coated; and the driving component drives the roller shaft to move in a direction parallel to the surface to be coated. The absorbing coating prepared by the present invention is dense, has controllable thickness, high consistency, good absorbing effect, and strong corrosion resistance. The device of the present invention is particularly suitable for preparing absorbing coatings such as polypyrrole / ferrite, graphene / ferrite, etc. containing granular and / or flaky materials. The preparation method is simple, easy to control, batchable, and low in cost, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the field of coating preparation, and relates to a roller coating device and a roller coating method and applications in the preparation of radar absorbing coatings. Background Art

[0002] The methods for preparing coatings on substrate surfaces generally include dip coating (also called impregnation), spray coating, roller coating (also called film coating or coating), rubbing coating, chemical deposition, electrodeposition, physical deposition, etc., and for large-area, flat substrate surface coating methods, the most widely used are dip coating, spray coating and roller coating. When the coating contains granular or flake materials such as ferrite, polypyrrole, silica, etc., it is easy to cause uneven composition when preparing the coating, and it cannot fully play its advantages as a coating framework and good adhesion.

[0003] In the roller coating device of the prior art, the roller coating component is rigidly connected to the fixed part, so the gap adjustment between the roller coating component and the coated substrate becomes very important and difficult to control. Poor control can easily affect the thickness and uniformity of the coating. Summary of the invention

[0004] In view of the above problems, the present invention proposes a roller coating device for preparing a coating, which is suitable for preparing coatings containing micro-nano particles (such as ferrite, conductive polymer, silicon dioxide), flaky materials (such as polypyrrole / ferrite, graphene / ferrite), etc. The present invention adopts a non-rigid connection between the connecting piece between the driving component and the roller shaft, automatically controls the thickness of the coating layer by the gravity of the roller shaft, and applies a pressure to the coating layer, so as to prepare a uniform, dense, and well-adhesive coating.

[0005] One object of the present invention is to provide a roller coating device, comprising a driving component, a roller shaft, a plate-like substrate, and a substrate fixing component; a coating portion is provided on part or all of the outer surface of the roller shaft; preferably, the coating portion is provided at the bottom of the roller shaft, and a non-rigid connection is adopted between the driving component and the roller shaft; the plate-like substrate is laid horizontally and fixed to the substrate fixing component; the roller shaft is in contact with the surface of the plate-like substrate to be coated; and the driving component drives the roller shaft to move in a direction parallel to the surface to be coated.

[0006] Optionally, the device further comprises a coating adding component; the coating adding component is used to add coating to the roller.

[0007] Preferably, the coating portion is made of a soft material or an elastic material, preferably a porous soft material or an elastic material that can absorb or adhere to the coating.

[0008] Optionally, the soft or elastic material is selected from at least one of sponge, plastic, fabric, and foam; the fabric is preferably a dust-free cloth.

[0009] Optionally, the coating portion has a thickness of 0.1 to 10 mm; optionally, the coating portion has a thickness of 0.5 to 5 mm; optionally, the coating portion has a thickness of 1 to 2 mm.

[0010] Optionally, the lower limit of the thickness of the coating portion may be independently selected from 0.1 mm, 0.5 mm, and 1 mm; the upper limit may be independently selected from 2 mm, 5 mm, and 10 mm.

[0011] Optionally, the roughness Ra of the outer surface of the coating portion is 0.1-10 μm; Optionally, the roughness Ra is 0.5-5 μm; Optionally, the roughness Ra is 1-2 μm. If the surface of the coating portion is too rough, the surface of the polypyrrole / ferrite coating will be rough. If the surface of the coating portion is too smooth, the coating cannot be stored or attached, and it is easy to slip, and the polypyrrole / ferrite coating cannot be applied to the surface of the substrate.

[0012] Optionally, the lower limit of the roughness Ra of the outer surface of the coating portion may be independently selected from 0.1 μm, 0.5 μm, and 1 μm; the upper limit may be independently selected from 2 μm, 5 μm, and 10 μm.

[0013] Optionally, the non-rigid connection is achieved by using a non-rigid connector, and the material of the non-rigid connector is selected from any one of a spring, a rubber belt, a nylon belt, and a fabric.

[0014] The mass of the roller will indirectly affect the pressure between the roller and the coated substrate. Preferably, the mass of the roller is 100 g to 2000 g; the optional mass is 200 g to 1000 g; the optional mass is 300 g to 500 g.

[0015] Another object of the present invention is to provide a method for roller coating a coating on a plate-like substrate surface using the above roller coating device, comprising the following steps:

[0016] (1) Fix the plate base material;

[0017] (2) Adding coating to the coating portion of the roller;

[0018] (3) After the coating portion of the roller contacts the surface to be coated of the plate-like substrate (preferably, the coating portion and the surface to be coated are in line contact), the driving component drives the roller to move in a direction parallel to the surface to be coated of the plate-like substrate, and rolls the coating on the surface to be coated to form a coating layer;

[0019] (4) Drying the coating layer to obtain the coating.

[0020] Depending on the application fields and thickness requirements of the coating, step (3) can be repeated multiple times, or steps (3) and (4) can be repeated multiple times.

[0021] Optionally, the coating contains granular and / or flaky materials; the mass fraction of the granular and / or flaky materials in the coating is 10-30%; preferably, the granular materials are micro-nano particles; preferably, the micro-nano particles are selected from at least one of ferrite, conductive polymer, silica, or a composite or mixture of two or more thereof.

[0022] Optionally, the coating is an absorbing coating; preferably, in step (2), the absorbing coating is selected from at least one of polypyrrole / ferrite and graphene / ferrite.

[0023] Preferably, in step (3), the pressure between the roller and the coated substrate is 0.9N to 19N, preferably 2N to 10N, and more preferably 3N to 5N. The roller coating pressure between the roller and the plate-like substrate directly affects the thickness, thickness consistency, and uniformity of the coating. Because the roller and the driving component are non-rigidly connected, the roller coating pressure and gap can be self-adjusted by the mass of the roller during the roller coating process.

[0024] In order to provide a dense polypyrrole / ferrite coating and ensure production efficiency, in the step (3), the running speed of the roller is 1 cm / min to 50 cm / min, preferably 5 cm / min to 30 cm / min, and more preferably 10 cm / min to 20 cm / min.

[0025] The lower limit of the running speed of the roller can be independently selected from 1 cm / min, 5 cm / min, 10 cm / min; the upper limit can be independently selected from 20 cm / min, 30 cm / min, 50 cm / min.

[0026] Another object of the present invention is to provide an application of any of the above-mentioned roller coating devices in the preparation of an absorbing coating, wherein the raw material of the absorbing coating is an absorbing paint; preferably, the absorbing paint is selected from at least one of polypyrrole / ferrite and graphene / ferrite.

[0027] The advantage of the present invention is that the roller coating device of the present invention is particularly suitable for the preparation of coatings containing micro-nano particles (such as ferrite, conductive polymer, silicon dioxide), flaky materials, etc. in the coating. The preparation method is simple, easy to control, can be mass-produced, low-cost, and has broad application prospects. The prepared coating is dense, the thickness is controllable, and the consistency is high. The prepared absorbing layer has a good absorbing effect. At the same time, the roller coating device of the present invention is particularly suitable for the preparation of absorbing coatings containing polypyrrole / ferrite, oxidized polypyrrole / ferrite and their derivatives. The preparation method is simple, easy to control, can be mass-produced, low-cost, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A top view of the roller coating device of the present invention.

[0029] Figure 2 A top view of the roller coating device of the present invention (when filling with paint).

[0030] 1 substrate fixing part, 2 roller, 3 coating part, 4 driving part, 5 connecting part, 6 plate-shaped substrate, 7 coating material adding part. DETAILED DESCRIPTION

[0031] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0032] Unless otherwise specified, the ferrite-containing absorbing coating in the embodiments of the present application can be purchased through commercial channels, such as NX-407 electromagnetic shielding coating of Shenzhen Nanxiang Conductive Material Technology Co., Ltd. or HSF54 electromagnetic protection shielding coating of Shenzhen Guoce Electronics Co., Ltd.

[0033] Example 1 Preparation of polypyrrole / ferrite coating

[0034] like Figure 1 and Figure 2 As shown, the roller coating device includes a driving component 4, a roller shaft 2, a plate-like substrate 6, a substrate fixing component 1 and a coating adding component 7 that can be used in conjunction with the driving component 4. The bottom of the outer surface of the roller shaft is provided with a coating portion 3, and the roller shaft 2 and the driving component 4 are connected by a non-rigid connecting member 5. In an optional embodiment, the connecting member 5 is an elastic connecting member.

[0035] Because the roller and the driving component are non-rigidly connected, the roller coating pressure and gap can be self-adjusted by the mass of the roller during the roller coating process. The gap between the roller and the plate-like substrate 6 is self-adjusted by the gravity of the roller, and the coating prepared by roller coating is complete and uniform in thickness.

[0036] In an optional embodiment, in order to make the coating part 3 absorb an appropriate amount of coating, the coating part 3 is made of cloth, such as non-woven fabric. When preparing the coating, the coating is dripped and stored in the coating part 3. After it is fully wetted and uniform, the driving component 4 drives the running roller to roll it onto the surface of the plate-like substrate 6, and a coating layer is formed on the surface of the plate-like substrate 6. The prepared coating has high consistency in thickness. Depending on the length or area of ​​the plate-like substrate, the coating can be added periodically or continuously in the middle. In order to adapt to the substrate with a slightly uneven surface to be rolled, the roller is in line contact with the plate-like substrate 6.

[0037] The polypyrrole / ferrite coating prepared by the invention is dense, has controllable thickness, high consistency and strong corrosion resistance.

[0038] The present invention is further described in detail below by way of examples. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0039] The analysis and testing methods in the examples of this application are as follows:

[0040] The absorbing frequency and shielding effectiveness of the absorbing coating were tested with Agilent-N5242A vector network analyzer. The continuity of the absorbing coating and the number of red dots in the copper sulfate test were tested according to GB / T8752-2006; the alkali resistance time of the absorbing coating was tested according to GB / T8013.1-2007.

[0041] An aluminum alloy plate with a size of 100mm*100mm*1mm is used as the plate-shaped substrate 6. After cleaning and degreasing with acetone and surface treatment, it is horizontally laid and fixed to the substrate fixing component 1. The connecting piece 5 between the roller 2 and the driving component 4 is a rubber belt. The coating part 3 is made of cloth with a thickness of 1mm. The surface roughness Ra of the cloth is 0.1μm. It is coated on the surface of the roller 2 and kept tight.

[0042] Add NX-407 electromagnetic shielding paint to the fabric and let it stand for 1 minute. When the fabric is completely soaked and no paint drips, run roller 2 with a pressure of 0.9N between the roller and the plate substrate and a running speed of 1cm / min. After roller coating, the average thickness of the coating layer is 5μm.

[0043] The aluminum alloy was placed in a forced air drying oven at 150° C. for drying and curing for 30 minutes to obtain a polypyrrole / ferrite coating with an average thickness of 2 μm.

[0044] Examples 2 to 6 Preparation of polypyrrole / ferrite coatings

[0045] The preparation of the polypyrrole / ferrite coating was the same as in Example 1, except that the thickness of the coating portion of the roller coating device, the pressure between the roller and the plate-like substrate, and the running speed of the roller were adjusted, as shown in Table 1.

[0046] Example 7

[0047] It is basically the same as the first embodiment, the only difference being that the connecting member 5 of the roller coating device is a spring.

[0048] Example 8

[0049] It is basically the same as Example 1, the only difference is that the connecting member 5 of the roller coating device is a nylon belt.

[0050] Example 9

[0051] It is basically the same as the first embodiment, the only difference being that the coating part 3 of the roller coating device is made of sponge.

[0052] Example 10

[0053] It is basically the same as the first embodiment, the only difference being that the coating part 3 of the roller coating device is made of plastic.

[0054] Comparative Example 1 Preparation of polypyrrole / ferrite coating

[0055] An aluminum alloy plate with a size of 100mm*100mm*1mm was used as the substrate to be coated. It was cleaned and degreased with acetone. After surface treatment, it was vertically fixed on the substrate fixing component 1 and immersed vertically in the NX-407 electromagnetic shielding coating at a rate of 1cm / min. It was kept for 5 minutes and lifted out of the coating at a rate of 1cm / min. The average thickness of the coating layer was 12μm. It was dried at 150°C for 30 minutes to obtain a polypyrrole / ferrite coating prepared on the surface of the aluminum alloy with an average thickness of 5μm.

[0056] Table 1 shows the parameters of the thickness of the coating portion, the pressure between the roller and the substrate, and the running speed of the roller in Examples 1 to 6.

[0057] Table 1

[0058]

[0059] The properties of the polypyrrole / ferrite coatings prepared in Examples 1 to 6 and Comparative Example 1 are shown in Table 2.

[0060] Comparative Example 2

[0061] It is basically the same as Example 1, the only difference being that the roller shaft 2 and the driving component 4 of the roller coating device are rigidly connected by stainless steel.

[0062] Table 2

[0063]

[0064] As shown in Table 2, the number of red dots in the copper sulfate test of the polypyrrole / ferrite coating prepared in Examples 1-6 is less than 5, indicating that the coating has good density, and the number of red dots in the copper sulfate test of the polypyrrole / ferrite coating prepared in Comparative Example 1 is greater than 5, indicating that the coating has poor density. The alkali resistance test time of the polypyrrole / ferrite coating prepared in Examples 1-6 is much longer than that of Comparative Example 1, indicating that the alkali resistance and corrosion resistance of the coating are significantly improved. The performance of the coatings of Examples 7-10 is similar to that of Example 1. The performance of the coating of Comparative Example 2 is similar to that of Comparative Example 1.

[0065] Embodiment 11

[0066] It is basically the same as Example 1, the only difference is that the roughness Ra of the surface of the coating part 3 of the roller coating device is 0.5 μm.

[0067] Example 12

[0068] It is basically the same as Example 1, the only difference is that the roughness Ra of the surface of the coating part 3 of the roller coating device is 1 μm.

[0069] Example 13

[0070] It is basically the same as Example 1, the only difference is that the roughness Ra of the surface of the coating part 3 of the roller coating device is 2 μm.

[0071] Embodiment 14

[0072] It is basically the same as Example 1, the only difference is that the roughness Ra of the surface of the coating part 3 of the roller coating device is 5 μm.

[0073] Embodiment 15

[0074] The method is basically the same as that of Example 1, except that the surface roughness Ra of the coating portion 3 of the roller coating device is 10 μm.

[0075] Comparative Example 3

[0076] It is basically the same as Example 1, the only difference being that the surface roughness Ra of the coating part 3 of the roller coating device is 0.05 μm.

[0077] Comparative Example 4

[0078] The method is basically the same as that of Example 1, except that the surface roughness Ra of the coating portion 3 of the roller coating device is 20 μm.

[0079] The properties of the polypyrrole / ferrite coatings prepared in Examples 11 to 15 and Comparative Examples 3 and 4 are shown in Table 3.

[0080] Table 3

[0081]

[0082] As shown in Table 3, the number of red dots in the copper sulfate test of the polypyrrole / ferrite coating prepared in Examples 11-15 is less than 5, indicating that the coating has good compactness, and the number of red dots in the copper sulfate test of the polypyrrole / ferrite coating prepared in Comparative Examples 3-4 is greater than 5, indicating that the coating has poor compactness. The alkali resistance test time of the polypyrrole / ferrite coating prepared in Examples 11-15 is much longer than that of the polypyrrole / ferrite coating prepared in Comparative Examples 3-4, indicating that the alkali resistance and corrosion resistance of the coating are significantly improved.

[0083] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for roller coating a coating on a plate-like substrate surface, characterized in that: A roller coating device is used, comprising a driving component, a roller shaft, a plate-shaped substrate, and a substrate fixing component; a coating portion is provided on a part or the entire outer surface of the roller shaft; The driving component and the roller shaft are connected in a non-rigid manner; The plate-like substrate is horizontally laid and fixed to the substrate fixing component; The roller is in contact with the surface of the plate-like substrate to be coated; The driving component drives the roller to move in a direction parallel to the surface to be coated; The following steps are involved: (1) Fix the plate-shaped base material; (2) Adding coating to the coating portion of the roller; (3) After the coating portion of the roller contacts the substrate to be coated, the driving component drives the roller to move in a direction parallel to the surface to be coated of the plate-like substrate, and rolls the surface to be coated to form a coating layer; (4) drying the coating layer to obtain the coating; The thickness of the coating portion is 0.1 to 10 mm; The roughness Ra of the outer surface of the coating portion is 0.1 to 10 μm; The non-rigid connection is achieved by using a non-rigid connector, and the material of the non-rigid connector is selected from any one of a spring, a rubber belt, a nylon belt, and a fabric; The pressure between the roller and the coated substrate is 0.9N to 19N; The running speed of the roller is 1 cm / min to 50 cm / min.

2. The method according to claim 1, characterized in that The device further comprises a coating material adding component; the coating material adding component is used for adding coating material to the roller shaft.

3. The method according to claim 1, characterized in that The coating portion is made of a soft material or an elastic material.

4. The method according to claim 1, characterized in that: The coating portion is made of a porous soft material or an elastic material.

5. The method according to claim 4, characterized in that The porous soft material or elastic material is selected from at least one of sponge, plastic, fabric, and foam; The fabric is a dust-free cloth.

6. The method according to claim 1, characterized in that The coating portion has a thickness of 0.5 to 5 mm.

7. The method according to claim 1, characterized in that The coating portion has a thickness of 1 to 2 mm.

8. The method according to claim 1, characterized in that The roughness Ra of the outer surface of the coating portion is 0.5 to 5 μm.

9. The method according to claim 1, characterized in that: The roughness Ra of the outer surface of the coating portion is 1 to 2 μm.

10. The method according to claim 1, characterized in that The mass of the roller is 100 g to 2000 g.

11. The method according to claim 1, characterized in that: The mass of the roller is 200 g to 1000 g.

12. The method according to claim 1, characterized in that The mass of the roller is 300 g to 500 g.

13. The method according to claim 1, characterized in that The coating comprises granular and / or flaky materials; The mass fraction of the granular and / or flaky material in the coating is 10 to 30%; The granular material is micro-nano particles; The micro-nano particles are selected from at least one of ferrite, conductive polymer, and silicon dioxide, or a composite or mixture of two or more thereof; The coating is a wave-absorbing coating, and is selected from at least one of polypyrrole / ferrite and graphene / ferrite.

14. The method according to claim 1, characterized in that The pressure between the roller and the coated substrate is 2N to 10N.

15. The method according to claim 1, characterized in that The pressure between the roller and the coated substrate is 3N to 5N.

16. The method according to claim 1, characterized in that The running speed of the roller is 5 cm / min to 30 cm / min.

17. The method according to claim 1, characterized in that The running speed of the roller is 10 cm / min to 20 cm / min.

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