Bottom surface integrated metal decorative plate coating and preparation process thereof

Abstract

The invention provides a bottom surface integrated metal decorative plate coating. The bottom surface integrated metal decorative plate coating comprises the following components in parts by weight: 16-24 parts of aliphatic urethane acrylate, 8-12 parts of aliphatic urethane acrylate, 13.8-21.6 parts of functional resin, 35-40 parts of a preservative, 2.8-5.5 parts of a first auxiliary agent and 4.5-10 parts of a second auxiliary agent. After the designed coating is cured, a paint film is good in adhesive force, good in abrasion resistance and acid resistance, high in weather resistance, long in service life and suitable for indoor and outdoor. The invention further provides a preparation method and a construction process of the bottom-surface integrated metal decorative plate coating, the coating designed by the invention is suitable for an electron beam irradiation curing mode, the primer and the finish paint are integrally arranged, and the coating has the characteristics of simple process, low energy consumption and high productivity.

Description

Technical Field

[0001] The invention relates to the field of plate coatings, and in particular to a bottom-surface integrated metal decorative plate coating and a preparation process thereof. Background Art

[0002] Existing metal decorative sheet coatings are usually a primer plus topcoat. Primers are mostly heat-cured, which consumes a lot of energy, has a slow curing speed, and is limited in production capacity. The large amount of volatile solvents in heat curing will have a great impact on environmental pollution; topcoats are generally heat-cured or UV-cured. The disadvantages of heat curing are similar to those of primers. The disadvantages of UV curing are slow curing speed, and the addition of fillers and pigments will lead to incomplete curing.

[0003] During the construction of thermosetting metal decorative panel coatings, it is usually necessary to pre-treat the surface of the panel, apply a thermosetting primer coating on the pre-treated surface, and apply a thermosetting topcoat coating on the primer surface after heat curing the primer coating. The coating is heat cured using heating equipment such as an oven. In this method, the thermosetting equipment occupies a large area and takes a long time to cure. The coating curing depth is closely related to the temperature and duration. It usually takes several hours or even days to achieve the required thorough curing. Thermosetting coatings also contain a large amount of volatile organic solvents. The production process requires that the volatile solvents be treated to meet the standards before they can be discharged. Improper treatment will affect the surrounding environment. This process coating requires a large investment in curing equipment, high energy consumption, and slow production speed.

[0004] During the construction of heat-curing + UV-curing metal decorative panel coatings, it is usually necessary to pre-treat the surface of the panel, apply a heat-curing primer coating on the pre-treated surface, heat-cure the primer coating, and then apply a UV-curing topcoat coating on the primer surface, and use UV light to cure the topcoat coating. Photoinitiators are usually required to be added to UV-curing topcoats, but the presence of photoinitiators will affect the weather resistance of the topcoat and produce a strong odor. When facing certain use environments with high weather resistance requirements, the existing process requires an additional layer of fluorocarbon topcoat to be applied after the topcoat to increase the weather resistance of the coating. Such a process is long, requires multi-step curing, consumes a lot of energy, has low production capacity, and increases costs.

[0005] The difference of the electron beam irradiation curing of the present invention is that the electron beam curing accelerator replaces the ultraviolet light curing equipment, the equipment has low energy consumption, a fast curing speed of only 0.003-0.005 seconds, a high curing depth of up to 0.3mm, and a good curing effect. The use of photoinitiators and soluble solvents is avoided in the coating components, which is safer and more environmentally friendly. Summary of the invention

[0006] The purpose of the present invention is to provide a bottom-and-surface integrated metal decorative plate coating, aiming to solve the problems of complicated construction procedures and poor coating performance of metal plate coatings in the prior art.

[0007] The object of the present invention is achieved through the following technical solutions: In the first aspect of the present invention, the present invention provides a bottom-integrated metal decorative sheet coating, comprising the following components in parts by weight:

[0008]

[0009] More specifically, the functional resin is composed of the following components in parts by weight:

[0010]

[0011] More specifically, the first auxiliary agent is composed of the following components in parts by weight:

[0012]

[0013] More specifically, the second auxiliary agent is composed of the following components in parts by weight:

[0014] 1.5-3 parts of titanium dioxide;

[0015] 2-4 parts of matting powder;

[0016] 1 to 3 parts of pigment.

[0017] More specifically, the pigment is an inorganic pigment.

[0018] In a second aspect of the present invention, the present invention provides a method for preparing a bottom-integrated metal decorative sheet coating, comprising the following steps:

[0019] Step S1: adding each component of the functional resin in parts by weight into a stirring device in sequence, setting the rotation speed to 600-800 r / min, stirring for 10 minutes, and preparing a first premix;

[0020] Step S2: adding the components of the first auxiliary agent to the first premix in parts by weight, setting the speed of the stirring device to 800-1000 r / min, stirring for 10 minutes, to obtain a second premix;

[0021] Step S3: maintaining the stirring speed of the stirring device at 500-600 r / min, and adding aliphatic urethane acrylate and aliphatic polyurethane acrylate to the second premix in parts by weight, and after the addition, adjusting the stirring speed to 2000 r / min. Stirring for 10 minutes to obtain a third premix;

[0022] Step S4: Maintain the stirring speed of the stirring device at 500-600 r / min, and add the components of the second auxiliary agent and the preservative to the third premix in parts by weight. After the addition is completed, adjust the stirring speed to 2000 r / min. Stir for 30 minutes to obtain a mixture;

[0023] Step S5: adding the mixture into a grinder, grinding the mixture to a fineness of less than 5 μm, and obtaining an integrated metal decorative sheet coating.

[0024] In a third aspect of the present invention, the present invention further provides a method for applying a bottom-integrated metal decorative sheet coating, comprising the following steps:

[0025] Step S1: evenly apply the coating on the surface of the metal plate;

[0026] Step S2: Curing the metal sheet with uniform coating on the surface by electron beam irradiation curing process to obtain a metal decorative sheet with uniform coating on the surface

[0027] The coating method is selected from any one of roller coating and spray coating.

[0028] More specifically, in the electron beam irradiation curing process, the electron accelerator is selected to be 150kev to 300kev, and the irradiation dose is 80 to 150kGy.

[0029] More specifically, the metal sheet is selected from any one of an aluminum sheet, a stainless steel sheet, an aluminum alloy sheet, a magnesium alloy sheet, and a zinc alloy sheet.

[0030] More specifically, the thickness of the paint film is preferably 50 to 80 μm.

[0031] The beneficial effects of the present invention are:

[0032] The bottom-integrated metal decorative plate coating designed by the present invention does not require the addition of soluble solvents, and the component utilization rate is 100%. Compared with the current solvent-based thermal curing method, no exhaust gas is generated, and no solvent storage and treatment is required, which greatly reduces the pressure on enterprises, reduces environmental pollution, and optimizes the working environment. Compared with UV curing, electron beam radiation curing avoids the addition and use of photoinitiators, has good synergistic effects between components, has high weather resistance, is environmentally friendly, and is more environmentally friendly and reliable.

[0033] The bottom-to-surface integrated metal decorative sheet coating designed by the present invention integrates the primer and the topcoat into an integrated design. No pre-priming is required during the construction process, which simplifies the construction process. The coating can be directly applied to the surface of the sheet, saving the use of primer and reducing the preparation cost of the sheet paint film. After the coating is cured, the coating has good adhesion to the sheet, high cross-linking density, and good comprehensive performance, which improves the high energy consumption, low production capacity, and complex process in the existing process.

[0034] The bottom-integrated metal decorative sheet coating designed by the present invention adopts electron beam curing, which has higher curing energy, faster curing speed, and precise and controllable penetration depth, and is no longer affected by factors such as the light transmittance, color, material, thickness, etc. of the replica material. The electron beam irradiation curing method is used to replace the solvent-based thermal curing production process and the initiator-containing ultraviolet light curing production process, which reduces the plant area requirements and reduces the overall comprehensive cost of the electron beam cured bottom-integrated metal decorative sheet production. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the specific implementation methods of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The object of the present invention is achieved through the following technical solutions: In the first aspect of the present invention, the present invention provides a bottom-integrated metal decorative sheet coating, comprising the following components in parts by weight:

[0037]

[0038]

[0039] In the formulation design of the present application, aliphatic urethane acrylate and aliphatic polyurethane acrylate are used together as the main resin. The aliphatic urethane acrylate has the characteristics of low viscosity and conformality, is particularly suitable for outdoor applications, and has excellent weather resistance. In the embodiments of the present application, the aliphatic urethane acrylate is selected from Sartomer, a manufacturer with a product number of CN991.

[0040] Aliphatic polyurethane acrylate has good flexibility, wear resistance, and yellowing resistance. In the embodiment of the present application, the aliphatic polyurethane acrylate is selected from the manufacturer of Allnex Resin (Foshan), and the product number is 1258. The main function of functional resin is to adjust the adhesion, toughness, wear resistance, heat resistance, water resistance and other properties of the bottom integrated metal decorative sheet coating.

[0041] The first additive mainly plays the role of defoaming, wetting and dispersing, stabilizing the coating, etc. in the preparation process of the coating. The second additive mainly plays the role of improving the visual color of the coating, and is used for color matching and gloss improvement of the coating.

[0042] The preservative is a pigment-grade mixed corrosion inhibitor in the form of light yellow powder. In the embodiment of the present application, the preservative selected is HYBRICORTM 204S, the oil absorption of the product is 25-36 pounds / 100 pounds, and the specific gravity is 2.40-2.70 grams / cubic centimeter. The preservative is most commonly used in casting and structural aluminum protective primer applications.

[0043] In some specific embodiments, the functional resin is composed of the following components in parts by weight:

[0044]

[0045] The addition of functional resin can be entangled and bonded with the molecular chains of aliphatic urethane acrylate and aliphatic polyurethane acrylate during subsequent cross-linking and curing, which can improve various performances of the coating.

[0046] Among them, isobornyl acrylate, in the embodiment of the present application, isobornyl acrylate is selected from Changxing Special Materials (Changshu) manufacturer, and the product number is EM70. Isobornyl acrylate can be used as a curing cross-linking diluting monomer material, and has the advantages of good adhesion, good toughness, good wear resistance, good heat resistance, good water resistance, etc.

[0047] Isodecyl acrylate, in the embodiment of the present application, isodecyl acrylate is selected from Changxing Special Materials (Changshu) manufacturer, and the product number is EM219. Isodecyl acrylate can be used as a curing cross-linking diluting monomer material, is a hydrophobic monomer, contains a long hydrophobic fatty chain, and has the characteristics of weather resistance, flexibility, adhesion, low shrinkage, high impact strength, and good water resistance.

[0048] Methacrylate stearate, in the embodiment of the present application, methacrylate stearate is selected from Changxing Special Materials (Changshu) manufacturer, and the product number is EM35. Methacrylate stearate can be used as a curing cross-linking diluting monomer material, has a long-chain hydrophobic main chain, and has the effect of enhancing flexibility. At the same time, it also has the characteristics of low hydrophobic shrinkage, good moisture resistance, good chemical resistance, good corrosion resistance, good hardness, fast curing, good flexibility, good weather resistance, and good water resistance.

[0049] Stearyl acrylate, in the embodiment of the present application, is selected from the manufacturer Sartomer, and the product number is SR257. Stearyl acrylate can be used as a curing cross-linking monomer material, and is a monofunctional monomer with a long-chain hydrophobic main chain, which can play a role in destroying foam. It has the characteristics of high reactivity, excellent wear resistance, good chemical resistance, good water resistance, high cross-linking density, moisture resistance, good corrosion resistance, good hardness, good weather resistance, good adhesion, good wetting and leveling, and outstanding salt spray resistance.

[0050] Allyl cinnamate. In the embodiments of the present application, allyl cinnamate is selected from Aladdin manufacturer with product number A135568. A135568 can be used as a curing and cross-linking intermediate material, wherein the cinnamate dienophile has an optimized balance of effectiveness in preventing discoloration when exposed to radiation, while having no negative impact on barrier properties.

[0051] In some specific embodiments, the first auxiliary agent is composed of the following components in parts by weight:

[0052]

[0053] Wetting dispersant, in the embodiment of the present application, the wetting dispersant is selected from BYK Chemical, the product number is BYK111, the copolymer containing acidic groups in the wetting dispersant can stabilize inorganic pigments, especially titanium dioxide. It can strongly reduce the viscosity of the grinding material. It reduces the surface tension of the liquid, has excellent dispersibility, stability and high temperature resistance, can increase gloss and reduce haze. The additive deflocculates the pigment in the coating through steric stabilization. Since the deflocculated pigment has a small particle size, high gloss can be obtained and the color intensity is enhanced. In addition, the transparency of transparent pigments and the hiding power of opaque pigments can also be improved. Due to the reduction in viscosity, the flowability is improved and the pigment content can be increased. When the electrostatic high-speed rotary cup equipment is used for construction, the haze of the coating containing inorganic pigments is significantly reduced. BYK111 in the present application can also be mixed with BYK160 or BYK161 or used as a substitute.

[0054] Defoamer, in the embodiment of the present application, the defoamer is selected from BYK Chemicals, and the product number is A525. A525 is a polyurethane system defoamer. In the coating preparation process, the defoamer / deaerator can reduce the surface tension of bubbles in the solution, improve leveling and wetting, and prevent the formation of Bénard cells. It reduces the surface tension by reducing the polarity of the resin system, and has good acid and alkali resistance, heat resistance, dispersibility and defoaming properties.

[0055] Stabilizer. In the examples of this application, the stabilizer is selected from Clariant, with product number 3058LIQ. It is a 70% PMA solution of non-alkaline low molecular free radical scavenger, belonging to the hindered amine light stabilizer (HALS), suitable for various liquid coatings, effectively preventing coating cracking, gloss loss and other paint diseases, and improving the service life of the coating.

[0056] UV absorber, the stabilizer in the embodiment of the present application is selected from Clariant manufacturer, product number 3206LIQ. It is a highly efficient oxalylanilide-based liquid UV absorber with low color value, perfect fit for QUV specifications, and no discoloration when exposed to metal ions.

[0057] Adhesion promoter, in the embodiment of the present application, the adhesion promoter is selected from the manufacturer of allnex resin (Foshan), product number is 170. It is an acidic acrylate adhesion promoter with higher reactivity and very good metal adhesion promotion effect. It can improve the adhesion to non-ferrous metal surfaces that are difficult to adhere to, and has an excellent improvement effect on the adhesion of decorative panels such as aluminum, aluminum alloy zinc, stainless steel, electroplated surfaces, etc.; it can also enhance the ductility and impact resistance of the coating. It does not change color in high-temperature rapid baking, and does not affect the weather resistance of the coating, nor does it affect the storage stability of the coating.

[0058] In some specific embodiments, the second auxiliary agent is composed of the following components in parts by weight:

[0059] 1.5-3 parts of titanium dioxide;

[0060] 2-4 parts of matting powder;

[0061] 1 to 3 parts of inorganic pigments.

[0062] Titanium dioxide, in the examples of the present application, is selected from the product produced by DuPont, and the product number is Ti-Pure R960. DuPont Ti-Pure R-960 is a rutile titanium dioxide pigment produced by the chlorination process, which is suitable for application fields with special requirements for anti-powdering, gloss retention and color retention. In addition to excellent external weather resistance, R-960 has very good grinding and dispersibility and significant hiding power and color acceptance.

[0063] Matting powder, in the embodiment of the present application, is selected from the manufacturer GRACE, with the product number SyloidRad 2005. Matting powder has the characteristics of high shear stability, resistance to excessive grinding, no hard precipitation in the coating during storage, no effect on electron beam curing performance, no side effect on interlayer adhesion, etc. It has high transparency and no haze formation on a smooth, wear-resistant, high-quality surface.

[0064] Pigment, in the embodiment of the present application, inorganic pigments produced by BASF are selected. Inorganic pigments have better weather resistance than organic pigments, fade slowly, and inorganic pigments can adapt well to the electron beam radiation curing process. Commonly used colored inorganic pigments mainly refer to high-performance inorganic pigments-metal oxide mixed phase pigments, including titanium chrome brown, copper chrome black, titanium nickel yellow, iron chrome black, iron zinc chrome brown, cobalt blue, cobalt green, bismuth yellow, etc. These colored inorganic pigments have good compatibility with most coatings, no color bleeding, no migration, strong hiding power, and their light resistance, weather resistance, high temperature resistance, acid and alkali resistance are all high-grade, even when diluted with white pigment, they also have excellent fastness to light, heat, climate and chemicals. Therefore, it is particularly suitable for exterior wall paint products with high requirements for light resistance, weather resistance, temperature resistance, etc., and outdoor use can be up to decades without fading. Metal decorative sheet can add inorganic pigments of corresponding colors in the bottom integrated metal decorative sheet paint according to the required appearance color.

[0065] The present invention also provides a method for preparing a bottom-integrated metal decorative sheet coating, comprising the following steps:

[0066] Step S1: adding each component of the functional resin in parts by weight to a stirring sand mill disperser in sequence, setting the rotation speed to 600-800 r / min, stirring for 10 minutes, to obtain a first premix;

[0067] Step S2: adding the components of the first auxiliary agent to the first premix in parts by weight, setting the speed to 800-1000 r / min in a stirring sand mill disperser, stirring for 10 minutes, to obtain a second premix;

[0068] Step S3: Maintain the stirring speed of the stirring sanding disperser at 500-600 r / min, and gradually and slowly add the aliphatic urethane acrylate and the aliphatic polyurethane acrylate to the second premix by weight. After the addition is completed, adjust the stirring speed to 2000 r / min. Stir for 10 minutes to obtain the third premix;

[0069] Step S4: Maintain the stirring speed of the stirring sanding disperser at 500-600 r / min, and add the components of the second auxiliary agent and the preservative to the third premix in parts by weight. After the second auxiliary agent is added, adjust the stirring speed to 2000 r / min. Stir for 30 minutes to obtain a mixture;

[0070] Step S5: Add the mixture into a grinder, grind the mixture to a fineness of less than 5 μm, and obtain the integrated metal decorative sheet paint. During the fine grinding, a scraper fineness meter can be used to test the dispersion fineness of the paint.

[0071] In some specific embodiments, the curing method during the construction of the bottom integrated metal decorative plate paint is an electron beam irradiation curing process, in which the electron accelerator is selected to be 150kev to 300kev, and the irradiation dose is 80 to 150kGy.

[0072] In some specific embodiments, the metal sheet is selected from one of an aluminum sheet, a stainless steel sheet, an aluminum alloy sheet, a magnesium alloy sheet and a zinc alloy sheet. In the following embodiments, an aluminum sheet is selected. The bottom integrated metal decorative sheet coating can be applied to the sheet surface by roller coating or spraying. In the following embodiments, spraying is used. The cured paint film thickness after coating is preferably 50 to 80 μm.

[0073] Based on the above coating formulation, coating formulation preparation method and coating application method, specific embodiments and specific performance test results are listed below:

[0074] Example:

[0075] Bottom-to-surface integrated metal decorative sheet coating formula:

[0076]

[0077]

[0078] Preparation process of bottom-to-surface integrated metal decorative sheet coating:

[0079] Step S1: add isobornyl acrylate, isodecyl acrylate, stearyl methacrylate, octadecyl acrylate, and allyl cinnamate gradually according to the weight parts in the above ratio, and stir for 10 minutes in a stirring sand mill disperser at 700r / min to prepare a first premix; Step S2: add a wetting dispersant, a defoamer, a stabilizer, an ultraviolet absorber, and an adhesion promoter to the first premix in the above ratio in sequence, and stir for 10 minutes at 900r / min to prepare a second premix; Step S3: adjust the stirring speed to 500r / min, and gradually and slowly add aliphatic urethane acrylate and aliphatic polyurethane acrylate in the above ratio in sequence to the second premix. In the mixture, after the addition is completed, the stirring speed is adjusted to 2000r / min and stirred for 10 minutes to obtain a third premix; step S4: adjust the stirring speed to 500r / min, and slowly add the matting powder, titanium dioxide, inorganic copper chromium black pigment, and preservative to the third premix in the above-mentioned proportion by weight. When adding, it is necessary to add in batches in small amounts, observe the degree of dispersion and add slowly. After the addition is completed, adjust the stirring speed to 2000r / min and stir for 30 minutes to obtain a mixture; step S5: take a small amount of the mixture and use a scraper fineness meter to test the dispersion fineness of the coating. The fineness is required to be ≤5μm. If it is not reached, the mixture needs to be added to the grinder and ground to a fineness of less than 5μm to obtain the final bottom integrated metal decorative plate coating.

[0080] The construction process of the bottom integrated metal decorative sheet paint:

[0081] The bottom integrated metal decorative sheet paint is evenly coated on each surface of the aluminum decorative sheet by spraying, and the evenly coated aluminum decorative sheet is transported by the conveying device to the electron accelerator irradiation bottom, and a 300kev electron accelerator is used, and the irradiation dose is set to 120KGy. Each surface of the aluminum decorative sheet is evenly irradiated for 0.5S and then taken out. Each surface of the aluminum decorative sheet is evenly covered with a paint film, and the average thickness of the paint film is measured to be 68μm.

[0082] The performance test of the paint film on the surface of the aluminum decorative sheet is carried out, and the performance test results are as follows:

[0083]

[0084]

[0085] According to the performance test results, the bottom integrated metal decorative sheet coating designed by the present application has good performance. It is coated on the surface of the metal sheet and has good performance after being cured by electron beam irradiation. It is qualified in the paint film adhesion test, paint film hardness test, wear resistance test, hydrochloric acid resistance test, nitric acid resistance test, solvent resistance test, mortar resistance test, impact resistance test, salt spray CASS test, salt spray-neutral test, moisture and heat resistance test, aging resistance test and welding nail connection test. The bottom integrated metal decorative sheet coating designed by the present invention has excellent performance. The coated sheet is suitable for indoor and outdoor decoration. The paint film has good adhesion and will not fall off after long-term use; the paint film has high hardness and good wear resistance, and is scratch-resistant during use; it has good acid resistance, solvent resistance, mortar resistance, rain erosion resistance and daily cleaning resistance; it has good moisture and heat resistance and aging resistance, long service life, and will not crack or fall off after long-term exposure outdoors; the welding nail connection is good, and the subsequent welding and cutting of the sheet has little effect on the paint film.

[0086] Although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0087] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bottom-integrated metal decorative sheet coating, It is characterized in that It includes the following components by weight:

2. The bottom-surface integrated metal decorative sheet coating according to claim 1, It is characterized in that The functional resin is composed of the following components in parts by weight:

3. The bottom-surface integrated metal decorative sheet coating according to claim 1, It is characterized in that The first auxiliary agent is composed of the following components in parts by weight:

4. The bottom-surface integrated metal decorative sheet coating according to claim 1, It is characterized in that The second auxiliary agent is composed of the following components in parts by weight: 1.5-3 parts of titanium dioxide; 2-4 parts of matting powder; 1 to 3 parts of pigment.

5. The bottom-surface integrated metal decorative sheet coating according to claim 4, It is characterized in that The pigment is an inorganic pigment.

6. A method for preparing the bottom-integrated metal decorative sheet coating according to any one of claims 1 to 5, It is characterized in that The following steps are involved: Step S1: adding each component of the functional resin in parts by weight into a stirring device in sequence, setting the rotation speed to 600-800 r / min, stirring for 10 minutes, and preparing a first premix; Step S2: adding the components of the first auxiliary agent to the first premix in parts by weight, setting the speed of the stirring device to 800-1000 r / min, stirring for 10 minutes, to obtain a second premix; Step S3: maintaining the stirring speed of the stirring device at 500-600 r / min, and adding aliphatic urethane acrylate and aliphatic polyurethane acrylate to the second premix in parts by weight, and after the addition is completed, adjusting the stirring speed to 2000 r / min, stirring for 10 minutes, to obtain a third premix; Step S4: maintaining the stirring speed of the stirring device at 500-600 r / min, and adding the components of the second auxiliary agent and the preservative to the third premix in parts by weight, and after the addition is completed, adjusting the stirring speed to 2000 r / min, stirring for 30 minutes, and obtaining a mixture; Step S5: adding the mixture into a grinder, grinding the mixture to a fineness of less than 5 μm, and obtaining a bottom-surface integrated metal decorative sheet coating.

7. A method for applying a coating for a bottom-integrated metal decorative sheet material according to any one of claims 1 to 5, It is characterized in that The following steps are involved: Step S1: evenly apply the coating on the surface of the metal plate; Step S2: curing the metal plate with a uniform coating on the surface by electron beam irradiation curing process to obtain a metal decorative plate with a uniform paint film on the surface; The coating method is selected from any one of roller coating and spray coating.

8. The construction method of the bottom-integrated metal decorative sheet coating according to claim 7, It is characterized in that In the electron beam irradiation curing process, the electron accelerator is selected to be 150kev to 300kev, and the irradiation dose is 80 to 150kGy.

9. The construction method of the bottom-integrated metal decorative sheet coating according to claim 7, It is characterized in that The metal sheet is selected from any one of an aluminum sheet, a stainless steel sheet, an aluminum alloy sheet, a magnesium alloy sheet, and a zinc alloy sheet.

10. The construction method of bottom-integrated metal decorative sheet coating according to claim 7, It is characterized in that The thickness of the paint film is 50 to 80 μm.

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