Preparation process of environment-friendly color steel plate

Abstract

The application discloses a preparation process of an environment-friendly color steel plate. The process comprises the following steps: (1) degreasing and cleaning a steel plate, coating a primer, baking, hot air drying, and obtaining a treated steel plate; (2) coating a top paint on the treated steel plate, baking, hot air drying, and obtaining an environment-friendly color steel plate; the primer comprises the following components: a water-based epoxy resin, sodium hydroxide, modified attapulgite, deionized water, lauryl alcohol, a polyacrylic acid-based dispersant, an organic silicon defoaming agent, an acrylic emulsion and alcohol ester twelve; the top paint comprises the following components: a water-soluble saturated polyester resin, a water-soluble amino resin, modified bamboo charcoal powder, cellulose acetate butyrate, carbon fiber, nano silver, a dispersant BYK-104S, ethylene glycol butyl ether and deionized water. The materials used in the preparation process are all environment-friendly raw materials, harmful substances such as formaldehyde and VOCs in the plate can be captured, and the color steel plate has a more environment-friendly effect.

Description

Technical Field

[0001] This application relates to the technical field of color steel sheets, and in particular to a manufacturing process for an environmentally friendly color steel sheet. Background Technology

[0002] Color steel sheet is a new type of multifunctional building material. It is a building material made by coating the surface of steel or aluminum sheets with paint through a roller coating process. It has the advantages of high strength, convenient processing and forming, good durability, fire resistance, water resistance, heat insulation and sound insulation. Therefore, it has been widely used in construction, home appliances, automobiles and other fields.

[0003] The coating process typically uses primer and topcoat, which are oil-based paints containing aromatic hydrocarbon diluents. During manufacturing and use, these paints release volatile organic compounds (VOCs), which pollute the atmosphere and may cause health problems. Summary of the Invention

[0004] To address the issue of volatile organic compounds being released during the manufacturing and use of oil-based coatings containing aromatic hydrocarbon diluents, this application provides a process for preparing environmentally friendly color-coated steel sheets.

[0005] This application provides a manufacturing process for environmentally friendly color-coated steel sheets, employing the following technical solution:

[0006] A manufacturing process for an environmentally friendly color-coated steel sheet includes the following steps:

[0007] (1) Degrease and clean the steel plate at a temperature of 80-85℃ for 20-25 minutes, then apply primer, bake at a temperature of 95-100℃, and dry with hot air to obtain the treated steel plate.

[0008] (2) Coat the steel plate processed in step (1) with topcoat, bake it at a temperature of 95-100℃, and dry it with hot air to obtain an environmentally friendly color steel plate.

[0009] The raw material components of the primer include the following components: waterborne epoxy resin, sodium hydroxide, modified attapulgite clay, deionized water, lauryl alcohol, polyacrylic acid-based dispersant, silicone defoamer, acrylic emulsion, and dodecyl alcohol ester.

[0010] The raw material components of the topcoat include the following components: water-soluble saturated polyester resin, water-soluble amino resin, modified bamboo charcoal powder, cellulose acetate butyrate, carbon fiber, nano silver, dispersant BYK-104S, ethylene glycol butyl ether, and deionized water.

[0011] By adopting the above technical solution, the steel plate is degreased and cleaned to remove oil, grease and other organic substances from the surface of the steel plate, reducing the separation of the primer from the steel surface, thereby improving the adhesion of the subsequent primer. The topcoat is then applied to protect the steel plate from corrosion and increase its durability. All raw materials used are environmentally friendly and can absorb harmful substances such as formaldehyde and VOCs in the plate, making the color steel plate more environmentally friendly.

[0012] In the primer, waterborne epoxy resin is a solvent-free, low-viscosity, and high-penetration coating with good adhesion properties. It is an environmentally friendly coating with low VOC content and excellent chemical resistance, water resistance, abrasion resistance, and corrosion resistance. Sodium hydroxide plays an important role as a catalyst and regulator in the waterborne epoxy resin. Modified attapulgite can adjust the viscosity of the system, increase the gloss, mechanical properties, abrasion resistance, and weather resistance of the primer, and slow down the flow rate of the system, thereby forming a more uniform primer coating. Moreover, modified attapulgite can firmly adhere to the steel plate surface, increasing the adhesion between the system and the steel plate. In addition, modified attapulgite has a strong adsorption and catalytic oxidation effect on VOCs, thereby reducing the amount of VOCs in the steel plate.

[0013] Lauryl alcohol, acting as a dispersant and wetting agent, ensures uniform mixing of all components, thereby improving the performance and quality of the primer coating. Polyacrylic acid-based dispersants, with their dispersing and emulsifying properties, can disperse modified attapulgite clay into the system solution, resulting in good stability and uniformity. Organosilicon defoamers enhance the stability of the primer system, preventing bubble aggregation and agglomeration during mixing. Acrylic emulsions act as adhesives in the coating, exhibiting good film-forming properties and ensuring tight adhesion between the primer and the steel plate. Dodecyl alcohol esters lower the primer's film-forming temperature, significantly improving film-forming properties and enhancing gloss, strength, and anti-chalking performance. The various components in the primer work together to form a uniform primer coating on the steel plate surface, exhibiting good environmental friendliness, mechanical properties, and adhesion.

[0014] In the topcoat, water-soluble saturated polyester resin has excellent water resistance and weather resistance, can maintain waterproof effect for a long time, does not contain toxic substances, and meets environmental protection requirements; water-soluble amino resin is an environmentally friendly coating material with excellent water resistance, chemical resistance, abrasion resistance and weather resistance; modified bamboo charcoal powder has porous and easily absorbent properties, which can form a powerful purification filter on the surface of the topcoat coating, capturing harmful substances such as formaldehyde and VOCs in the board in all directions, making the topcoat coating more environmentally friendly.

[0015] Cellulose acetate butyrate possesses good water resistance, weather resistance, film-forming flexibility, and high transparency, reducing clumping in the topcoat and enhancing releveling properties. Carbon fiber exhibits high strength, high modulus, low density, and low coefficient of thermal expansion, improving the mechanical properties of the topcoat coating, enhancing its toughness and impact resistance, and also improving its abrasion resistance. Nano-silver possesses excellent antibacterial properties, with a large specific surface area and high activity, enhancing the antibacterial properties of the topcoat coating. Dispersant BYK-104S prevents floating color caused by mixing nano-silver with other components, ensuring uniform mixing of all components. Ethylene glycol butyl ether regulates the evaporation rate of the topcoat, making the drying speed more controllable and improving its leveling properties. The various components, when mixed together, collectively improve the mechanical properties, abrasion resistance, environmental friendliness, and adhesion of the topcoat coating.

[0016] Preferably, the raw material components of the topcoat, by weight, include the following components: 50-60 parts of water-soluble saturated polyester resin, 8-12 parts of water-soluble amino resin, 12-15 parts of modified bamboo charcoal powder, 6-9 parts of cellulose acetate butyrate, 4-8 parts of carbon fiber, 1-3 parts of nano silver, 2-2.5 parts of dispersant BYK-104S, 3-5 parts of ethylene glycol butyl ether, and 10-15 parts of deionized water.

[0017] By adopting the above technical solution, the components of each raw material are further defined, so that the prepared topcoat has better mechanical properties, wear resistance and adhesion, and extends the service durability of steel plates. Modified bamboo charcoal powder has the characteristics of being porous and easy to absorb and having high mechanical strength. Nano silver has strong bactericidal properties, and cellulose acetate butyrate has good water resistance, weather resistance and film-forming flexibility. The various components work together to improve the mechanical properties, wear resistance, environmental protection and adhesion of the topcoat.

[0018] Preferably, the preparation method of the modified bamboo charcoal powder includes the following steps:

[0019] (1) Disperse bamboo charcoal powder in sodium hydroxide solution, stir at 80-85℃ for 1-2 hours, wash with water, and calcine at 350-400℃ for 2-3 hours to obtain treated bamboo charcoal powder;

[0020] (2) Disperse nano-titanium dioxide in an ethanol solution of monolaurate glycerol and dry to obtain treated nano-titanium dioxide.

[0021] (3) Disperse the bamboo charcoal powder treated in step (1) in deionized water, stir at 4-10℃ for 10-20 min, then add the nano titanium dioxide treated in step (2), add modified sodium alginate, stir for 1-2 h, filter and dry to obtain modified bamboo charcoal powder.

[0022] By adopting the above technical solution, sodium hydroxide solution erodes bamboo charcoal powder to a certain extent, increasing the porosity and specific surface area of ​​bamboo charcoal powder. Calcination further removes organic impurities from bamboo charcoal powder, further improving the pore structure of bamboo charcoal powder, which is conducive to the loading of subsequent components.

[0023] The ethanol solution of glyceryl monolaurate has good surface activity and emulsifying effect, which can improve the surface activity of nano-titanium dioxide, enhance the dispersion of nano-titanium dioxide, and facilitate the subsequent loading of nano-titanium dioxide.

[0024] Bamboo charcoal powder is dispersed in deionized water, and nano-titanium dioxide is added. The nano-titanium dioxide can be loaded into the porous structure of the bamboo charcoal powder, improving its weather resistance, photocatalytic activity, adsorption, and self-cleaning properties, and enabling it to adsorb VOCs. Modified sodium alginate has certain viscosity and film-forming properties, which can coat the bamboo charcoal powder, making the bamboo charcoal powder and nano-titanium dioxide bond more tightly, further increasing the performance stability of the bamboo charcoal powder, and helping to improve its mechanical properties, adsorption, and weather resistance. It can then be applied to topcoats to improve their corresponding performance.

[0025] Preferably, the mass ratio of the bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate is 1:0.4-0.7:0.06-0.09.

[0026] By adopting the above technical solution, the mass ratio of bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate is further limited within a certain range. Bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate have a synergistic effect. Bamboo charcoal powder has good mechanical properties and adsorption capacity, nano titanium dioxide has good weather resistance and can be loaded in the pores of bamboo charcoal powder, improving the weather resistance of bamboo charcoal powder. Modified sodium alginate has certain viscosity and film-forming properties and can coat bamboo charcoal powder, so that nano titanium dioxide is firmly loaded on the surface of bamboo charcoal powder, improving the performance stability of bamboo charcoal powder, which helps to improve the corresponding performance of the topcoat in the future.

[0027] Preferably, the preparation method of the modified sodium alginate includes the following steps: dispersing sodium alginate in deionized water, adding triethylenediamine and epichlorohydrin, stirring at room temperature for 1-2 hours, then adding xanthan gum, and continuing to stir to obtain modified sodium alginate.

[0028] By adopting the above technical solution, epichlorohydrin is used as a crosslinking agent to crosslink with sodium alginate to obtain crosslinked sodium alginate, which improves the mechanical properties of sodium alginate such as strength and tensile strength. Triethylenediamine is used as a catalyst to accelerate the reaction between epichlorohydrin and sodium alginate. The addition of xanthan gum increases the viscosity and stability of crosslinked sodium alginate, improves the film-forming properties of subsequent crosslinked sodium alginate, and helps with the subsequent related application performance.

[0029] Preferably, the raw material components of the primer, by weight, include the following components: 16-24 parts of waterborne epoxy resin, 1-3 parts of sodium hydroxide, 5-10 parts of modified attapulgite, 30-40 parts of deionized water, 0.5-1.5 parts of lauryl alcohol, 1.5-2 parts of polyacrylic acid-based dispersant, 0.4-0.8 parts of silicone defoamer, 20-25 parts of acrylic emulsion, and 1.5-2.5 parts of dodecyl alcohol ester.

[0030] By adopting the above technical solution, the components of each raw material are further defined, so that the prepared primer has better mechanical properties, wear resistance, environmental protection and adhesion, and extends the service durability of the steel plate. The modified attapulgite can be firmly loaded on the surface of the steel plate, increasing the adhesion between the system and the steel plate. The various components work together to improve the mechanical properties, wear resistance, environmental protection and adhesion of the topcoat.

[0031] Preferably, the method for preparing the modified attapulgite includes the following steps:

[0032] (1) Disperse attapulgite in anhydrous ethanol, dry it, add sodium silicate, stir at 80-85℃ for 2-3 hours, filter and dry it to obtain the treated attapulgite.

[0033] (2) Disperse hollow ZnO microspheres in anhydrous ethanol, add graphene oxide, ultrasonically disperse for 2-3 h, then heat at 150-160℃ for 20-24 h, wash with water and dry to obtain the treated hollow ZnO microspheres;

[0034] (3) Disperse the attapulgite treated in step (1) in anhydrous ethanol, add the hollow ZnO microspheres treated in step (2), stir for 2-3 hours, filter and dry to obtain modified attapulgite.

[0035] By adopting the above technical solutions, attapulgite has good adsorption, thickening and stability, sodium silicate has certain adhesion, detergency and emulsifying properties, which helps to uniformly disperse the subsequent components; hollow ZnO microspheres have good adsorption and photocatalytic activity, and graphene oxide has good mechanical properties and adsorption, which can be loaded on the surface and pores of hollow ZnO microspheres, further improving the mechanical properties and adsorption of hollow ZnO microspheres.

[0036] Graphene oxide and hollow ZnO microspheres were mixed and heated at 150-160℃ for 20-24 hours to obtain hollow ZnO microspheres loaded with reduced graphene oxide, which further improved the performance stability of the hollow ZnO microspheres. The hollow ZnO microspheres loaded with reduced graphene oxide were then mixed with attapulgite, so that the hollow ZnO microspheres loaded with reduced graphene oxide were loaded on the surface and in the pores of attapulgite, thereby improving the mechanical and adsorption properties of attapulgite. This helps to improve the adsorption and mechanical properties of the primer and helps to reduce the content of harmful substances such as VOCs.

[0037] Preferably, the mass ratio of the attapulgite clay, hollow ZnO microspheres, and graphene oxide is 1g:0.2-0.5g:0.07-0.09mg.

[0038] By adopting the above technical solution, the mass ratio of attapulgite, hollow ZnO microspheres, and graphene oxide is further limited within a certain range, improving the mechanical properties and adsorption capacity of attapulgite. This helps to make the primer bond more tightly to the steel plate. Attapulgite, hollow ZnO microspheres, and graphene oxide have a synergistic effect. Graphene oxide can be loaded on the surface and pores of hollow ZnO microspheres, and hollow ZnO microspheres can be loaded on the surface and pores of attapulgite, further improving the mechanical properties and adsorption capacity of attapulgite, which will help improve the corresponding properties of the primer in the future.

[0039] Preferably, the hollow ZnO microspheres have a particle size of 50-70 nm and a shell thickness of 30-70 nm.

[0040] By adopting the above technical solution, the particle size and shell thickness of hollow ZnO microspheres are further limited, so that the hollow ZnO microspheres have better adsorption, photocatalytic activity, weather resistance and durability, and improve the mechanical properties of subsequent primers.

[0041] Preferably, in step (1), a degreasing solution is used for degreasing and cleaning, the primer thickness is 20-30μm, and the topcoat thickness is 40-50μm.

[0042] By adopting the above technical solution, the degreasing liquid has wettability, penetrability, emulsification and dispersibility, which can remove dirt from the surface of steel plates. Using the degreasing liquid for degreasing and cleaning improves the adhesion of the coating on the surface of the steel plate and extends the service life of the steel plate. Setting appropriate primer and topcoat thicknesses ensures that the surface of the steel plate is uniform, while guaranteeing the mechanical properties, durability and weather resistance of the steel plate.

[0043] In summary, this application has the following beneficial effects:

[0044] 1. In this application, the steel plate is degreased and cleaned to remove oil and grease and other organic substances from the surface of the steel plate, reducing the separation of the primer from the steel surface, thereby improving the adhesion of the subsequent primer. The topcoat is then applied to protect the steel plate from corrosion and increase its durability. All raw materials used are environmentally friendly and can absorb harmful substances such as formaldehyde and VOCs in the plate, making the color steel plate more environmentally friendly.

[0045] 2. In the primer of this application, the water-based epoxy resin is a solvent-free, low-viscosity, and high-penetration coating with good adhesion properties. It is an environmentally friendly coating with low VOC content and excellent chemical resistance, water resistance, abrasion resistance, and corrosion resistance. The modified attapulgite can adjust the viscosity of the system, increase the gloss, mechanical properties, abrasion resistance, and weather resistance of the primer, and slow down the flow rate of the system, thereby forming a more uniform primer coating. Moreover, the modified attapulgite can firmly adhere to the steel plate surface, increasing the adhesion between the system and the steel plate. The modified attapulgite has a strong adsorption and catalytic oxidation effect on VOCs, thereby reducing the amount of VOCs in the steel plate.

[0046] 3. In the topcoat of this application, the water-soluble saturated polyester resin has excellent water resistance and weather resistance, can maintain waterproof effect for a long time, does not contain toxic substances, and meets environmental protection requirements; the water-soluble amino resin is an environmentally friendly coating material with excellent water resistance, chemical resistance, wear resistance and weather resistance; the modified bamboo charcoal powder has porous and easily absorbent properties, which can form a powerful purification filter on the surface of the topcoat coating, capturing harmful substances such as formaldehyde and VOCs in the board in all directions, making the topcoat coating more environmentally friendly. Detailed Implementation

[0047] The present application will be further described in detail below with reference to the embodiments.

[0048] The raw materials used in the examples and comparative examples are all commercially available.

[0049] Preparation example of modified bamboo charcoal powder

[0050] Preparation Example 1-1

[0051] The preparation method of modified bamboo charcoal powder includes the following steps:

[0052] (1) Disperse 1.2 kg of bamboo charcoal powder in 2.5 L of sodium hydroxide solution with a mass fraction of 18%, stir at 85 °C for 2 h, wash with water, and calcine at 400 °C for 3 h to obtain the treated bamboo charcoal powder.

[0053] (2) Disperse nano-titanium dioxide in an ethanol solution of monolaurate and dry it to obtain treated nano-titanium dioxide; dissolve 0.2 kg of monolaurate in 2 L of ethanol solution and stir evenly to obtain an ethanol solution of monolaurate.

[0054] (3) Disperse the bamboo charcoal powder treated in step (1) in 3L of deionized water, stir at 8℃ for 15min, then add the nano titanium dioxide treated in step (2), add modified sodium alginate, stir for 2h, filter and dry to obtain modified bamboo charcoal powder.

[0055] The mass ratio of bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate is 1:0.7:0.09.

[0056] The preparation method of modified sodium alginate includes the following steps: 1 kg of sodium alginate is dispersed in 3 L of deionized water, 0.1 kg of triethylenediamine and 0.5 kg of epichlorohydrin are added, and the mixture is stirred at room temperature for 2 h. Then, 0.05 kg of xanthan gum is added, and the mixture is stirred for another 2 h to obtain modified sodium alginate.

[0057] Preparation Examples 1-2

[0058] The difference from preparation example 1-1 is that nano-titanium dioxide is not added in step (2).

[0059] Preparation Examples 1-3

[0060] The difference from Preparation Example 1-1 is that no modified sodium alginate is added in step (3).

[0061] Preparation Examples 1-4

[0062] The difference from Preparation Example 1-1 is that the mass ratio of bamboo charcoal powder, nano titanium dioxide and modified sodium alginate is 1:0.4:0.06.

[0063] Preparation Examples 1-5

[0064] The difference from Preparation Example 1-1 is that the mass ratio of bamboo charcoal powder, nano titanium dioxide and modified sodium alginate is 1:0.1:0.01.

[0065] Preparation Examples 1-6

[0066] The difference from Preparation Example 1-1 is that epichlorohydrin is not added in the preparation method of modified sodium alginate.

[0067] Preparation Examples 1-7

[0068] The difference from Preparation Example 1-1 is that xanthan gum is not added in the preparation method of modified sodium alginate.

[0069] Preparation example of modified attapulgite

[0070] Preparation Example 2-1

[0071] The preparation method of modified attapulgite includes the following steps:

[0072] (1) Disperse 0.8 kg of attapulgite in 2 L of anhydrous ethanol, dry, add 0.06 kg of sodium silicate, stir at 85 °C for 3 h, filter and dry to obtain the treated attapulgite.

[0073] (2) Hollow ZnO microspheres were dispersed in 1.5L of anhydrous ethanol, graphene oxide was added, and the mixture was ultrasonically dispersed for 3h. Then it was heated at 160℃ for 24h, washed with water and dried to obtain the treated hollow ZnO microspheres.

[0074] (3) Disperse the attapulgite soil treated in step (1) in 2.5L of anhydrous ethanol, add the hollow ZnO microspheres treated in step (2), stir for 3h, filter and dry to obtain modified attapulgite soil;

[0075] The mass ratio of attapulgite, hollow ZnO microspheres, and graphene oxide is 1g:0.2g:0.07mg.

[0076] The hollow ZnO microspheres have a particle size of 50-70 nm and a shell thickness of 30-70 nm.

[0077] Preparation Example 2-2

[0078] The difference from preparation example 2-1 is that hollow ZnO microspheres are not added in step (2).

[0079] Preparation Examples 2-3

[0080] The difference from preparation example 2-1 is that graphene oxide is not added in step (2).

[0081] Preparation Examples 2-4

[0082] The difference from Preparation Example 2-1 is that the mass ratio of attapulgite, hollow ZnO microspheres and graphene oxide is 1 g: 0.5 g: 0.09 mg.

[0083] Preparation Examples 2-5

[0084] The difference from Preparation Example 2-1 is that the mass ratio of attapulgite, hollow ZnO microspheres and graphene oxide is 1g:0.8g:0.01mg.

[0085] Example

[0086] Example 1

[0087] A manufacturing process for an environmentally friendly color-coated steel sheet includes the following steps:

[0088] (1) The steel plate is degreased and cleaned at 85°C for 25 minutes, then coated with primer, baked at 98°C, and dried with hot air to obtain the treated steel plate.

[0089] (2) The steel plate processed in step (1) is coated with topcoat, baked at 99°C, and dried with hot air to obtain an environmentally friendly color steel plate.

[0090] The raw material components of the primer, by weight, include the following components: 24 kg of waterborne epoxy resin, 3 kg of sodium hydroxide, 10 kg of modified attapulgite clay, 40 kg of deionized water, 1.5 kg of lauryl alcohol, 2 kg of polyacrylic acid-based dispersant, 0.4 kg of silicone defoamer, 25 kg of acrylic emulsion, and 2.5 kg of dodecyl alcohol ester.

[0091] The raw material components of the topcoat, by weight, include the following components: 60 kg of water-soluble saturated polyester resin, 12 kg of water-soluble amino resin, 15 kg of modified bamboo charcoal powder, 9 kg of cellulose acetate butyrate, 8 kg of carbon fiber, 3 kg of nano silver, 2.5 kg of dispersant BYK-104S, 5 kg of ethylene glycol butyl ether, and 10 kg of deionized water.

[0092] In step (1), degreasing solution is used for degreasing and cleaning. The thickness of the primer is 20-30μm and the thickness of the topcoat is 40-50μm. The degreasing solution is purchased from Dalson Chemical (Guangzhou) Co., Ltd., model DE-505H.

[0093] The modified bamboo charcoal powder was prepared using Preparation Example 1-1, and the modified attapulgite clay was prepared using Preparation Example 2-1.

[0094] Example 2

[0095] An environmentally friendly color steel plate preparation process differs from Example 1 in that it includes the following steps: (1) the steel plate is degreased and cleaned at 80°C for 20 minutes, then coated with primer, baked at 95°C, and dried with hot air to obtain the treated steel plate.

[0096] (2) The steel plate processed in step (1) is coated with topcoat, baked at 95°C, and dried with hot air to obtain an environmentally friendly color steel plate.

[0097] The raw material components of the primer, by weight, include the following components: 16 kg of waterborne epoxy resin, 1 kg of sodium hydroxide, 5 kg of modified attapulgite clay, 30 kg of deionized water, 0.5 kg of lauryl alcohol, 1.5 kg of polyacrylic acid-based dispersant, 0.8 kg of silicone defoamer, 20 kg of acrylic emulsion, and 1.5 kg of dodecyl alcohol ester.

[0098] The raw material components of the topcoat, by weight, include the following components: 50 kg of water-soluble saturated polyester resin, 8 kg of water-soluble amino resin, 12 kg of modified bamboo charcoal powder, 6 kg of cellulose acetate butyrate, 4 kg of carbon fiber, 1 kg of nano silver, 2 kg of dispersant BYK-104S, 3 kg of ethylene glycol butyl ether, and 15 kg of deionized water.

[0099] Example 3

[0100] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-2.

[0101] Example 4

[0102] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-3.

[0103] Example 5

[0104] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-4.

[0105] Example 6

[0106] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-5.

[0107] Example 7

[0108] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-6.

[0109] Example 8

[0110] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified bamboo charcoal powder is prepared using Preparation Examples 1-7.

[0111] Example 9

[0112] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified attapulgite clay is prepared using Preparation Example 2-2.

[0113] Example 10

[0114] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified attapulgite clay is prepared using Preparation Examples 2-3.

[0115] Example 11

[0116] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified attapulgite clay is prepared using Preparation Examples 2-4.

[0117] Example 12

[0118] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that the modified attapulgite clay is prepared using Preparation Examples 2-5.

[0119] Comparative Example

[0120] Comparative Example 1

[0121] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that no primer is applied.

[0122] Comparative Example 2

[0123] An environmentally friendly color steel plate preparation process differs from Example 1 in that it does not involve applying a topcoat.

[0124] Comparative Example 3

[0125] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that modified attapulgite is not added to the primer.

[0126] Comparative Example 4

[0127] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that attapulgite is used instead of modified attapulgite in the primer.

[0128] Comparative Example 5

[0129] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that modified bamboo charcoal powder is not added to the topcoat.

[0130] Comparative Example 6

[0131] The preparation process of an environmentally friendly color steel plate differs from that of Example 1 in that an equal amount of bamboo charcoal powder is used instead of modified bamboo charcoal powder in the topcoat.

[0132] Performance testing

[0133] The environmentally friendly color steel sheets prepared in Examples 1-12 and Comparative Examples 1-6 were subjected to performance tests. The drying time was tested according to GB / T1728-1979, the paint film adhesion was tested according to GB / T 9286-1998, the impact resistance was tested according to GB / T1732, the pencil hardness was tested according to GB / T 6739-2006, the peel strength at 180℃ was tested according to GB 2792, the elongation at break was tested according to GB 528, and the tensile strength was tested according to GB 529. The results are shown in Table 1.

[0134] Table 1 Test data for the examples and comparative examples

[0135]

[0136] As can be seen from Table 1, the environmentally friendly color steel plates prepared in Examples 1-2, 5, and 11 of this application have good adhesion and mechanical properties. Among them, the surface drying time of Example 1 is 20 min, the actual drying time is 10 h, the paint film adhesion is grade 0, the impact resistance is 58 cm·kg, the peel strength at 180℃ is 0.55 N / 25 mm, the elongation at break is 220%, and the tensile strength is 18 MPa. This indicates that the paint film of the prepared color steel plate has good adhesion, and at the same time has high impact resistance, peel strength, elongation at break, and tensile strength, thereby extending the durability of the steel plate.

[0137] In Example 3, the preparation method of modified bamboo charcoal powder did not include nano-titanium dioxide. As shown in Table 1, the surface drying time was 27 min, the actual drying time was 12 h, the paint film adhesion was grade 1, the impact resistance was 50 cm·kg, the peel strength at 180℃ was 0.34 N / 25 mm, the elongation at break was 205%, and the tensile strength was 12 MPa. This indicates that nano-titanium dioxide can be loaded into the pore structure of bamboo charcoal powder, improving the weather resistance, photocatalytic activity, adsorption and self-cleaning properties of bamboo charcoal powder, and can adsorb VOCs, thereby improving the relevant performance of steel plate coatings.

[0138] In Example 4, the preparation method of modified bamboo charcoal powder did not include modified sodium alginate. As shown in Table 1, the surface drying time was 26 min, the actual drying time was 12 h, the film adhesion was grade 1, the impact resistance was 49 cm·kg, the peel strength at 180℃ was 0.33 N / 25 mm, the elongation at break was 200%, and the tensile strength was 11 MPa. This indicates that the modified sodium alginate has certain adhesion and film-forming properties, which can coat the bamboo charcoal powder, making the bamboo charcoal powder and nano titanium dioxide bond more tightly, further increasing the performance stability of the bamboo charcoal powder, and helping to improve the mechanical properties, adsorption, and weather resistance of the bamboo charcoal powder. It can then be applied to the topcoat to improve the corresponding performance of the topcoat.

[0139] Example 6 altered the mass ratio of bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate. Table 1 shows that the surface drying time, actual drying time, paint film adhesion, impact resistance, 180℃ peel strength, elongation at break, and tensile strength of the color-coated steel sheet were all superior to those of Examples 3-4, but inferior to Examples 1 and 5. This indicates a synergistic effect among bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate. Bamboo charcoal powder possesses good mechanical properties and adsorption capacity; nano titanium dioxide exhibits good weather resistance and can be loaded within the pores of bamboo charcoal powder, improving its weather resistance; and modified sodium alginate has certain viscosity and film-forming properties, enabling it to coat the bamboo charcoal powder, allowing the nano titanium dioxide to be firmly loaded on the surface of the bamboo charcoal powder, thus improving the performance stability of the bamboo charcoal powder and subsequently contributing to improved performance of the topcoat.

[0140] In Example 7, the preparation method of modified sodium alginate did not include epichlorohydrin. As shown in Table 1, the surface drying time was 24 min, the actual drying time was 11 h, the film adhesion was grade 1, the impact resistance was 53 cm·kg, the peel strength at 180℃ was 0.37 N / 25 mm, the elongation at break was 206%, and the tensile strength was 13 MPa. This indicates that epichlorohydrin can crosslink with sodium alginate to obtain crosslinked sodium alginate, which improves the strength, fracture strength, and other mechanical properties of sodium alginate, and can subsequently improve the relevant properties of modified bamboo charcoal powder.

[0141] In Example 8, the preparation method of modified sodium alginate did not include xanthan gum. As shown in Table 1, the surface drying time was 25 min, the actual drying time was 11 h, the film adhesion was grade 1, the impact resistance was 51 cm·kg, the peel strength at 180℃ was 0.35 N / 25 mm, the elongation at break was 203%, and the tensile strength was 12 MPa. This indicates that the addition of xanthan gum increased the viscosity and stability of the crosslinked sodium alginate, improved the film-forming properties of the subsequent crosslinked sodium alginate, and contributed to its subsequent performance.

[0142] In Example 9, the preparation method of modified attapulgite did not include hollow ZnO microspheres. As shown in Table 1, the surface drying time was 29 min, the actual drying time was 14 h, the paint film adhesion was grade 1, the impact resistance was 48 cm·kg, the peel strength at 180℃ was 0.32 N / 25 mm, the elongation at break was 190%, and the tensile strength was 10 MPa. This indicates that the hollow ZnO microspheres have good adsorption and photocatalytic activity, which will help improve the adsorption properties of attapulgite and thus improve other properties of the attapulgite.

[0143] In Example 10, the preparation method of modified attapulgite did not include graphene oxide. As shown in Table 1, the surface drying time was 28 min, the actual drying time was 13 h, the paint film adhesion was grade 1, the impact resistance was 49 cm·kg, the peel strength at 180℃ was 0.34 N / 25 mm, the elongation at break was 193%, and the tensile strength was 11 MPa. This indicates that graphene oxide has good mechanical properties and adsorption properties, and can be loaded on the surface and in the pores of hollow ZnO microspheres, further improving the mechanical properties and adsorption properties of hollow ZnO microspheres. This will help improve the adsorption and mechanical properties of attapulgite in the future.

[0144] Example 12 changed the mass ratio of attapulgite, hollow ZnO microspheres, and graphene oxide. As shown in Table 1, the surface drying time, actual drying time, paint film adhesion, impact resistance, 180℃ peel strength, elongation at break, and tensile strength of the color steel plate were all better than those of Examples 9-10, but worse than those of Examples 1 and 11. This indicates that attapulgite, hollow ZnO microspheres, and graphene oxide have a synergistic effect. Graphene oxide can be loaded on the surface and pores of hollow ZnO microspheres, and hollow ZnO microspheres can be loaded on the surface and pores of attapulgite, further improving the mechanical properties and adsorption properties of attapulgite, which will help improve the corresponding properties of the primer.

[0145] Comparative Example 1, without primer, showed a surface drying time of 18 min, a complete drying time of 9 h, a paint film adhesion grade of 2, an impact resistance of 40 cm·kg, a peel strength of 0.21 N / 25 mm at 180℃, an elongation at break of 170%, and a tensile strength of 7 MPa. This indicates that not applying primer significantly affects the coating performance of the color steel plate. The various components in the primer work together to form a uniform primer coating on the surface of the steel plate, exhibiting good environmental friendliness, mechanical properties, and adhesion.

[0146] Comparative Example 2, without topcoat, shows in Table 1 that the surface drying time was 17 min, the actual drying time was 9 h, the paint film adhesion was grade 2, the impact resistance was 41 cm·kg, the peel strength at 180℃ was 0.20 N / 25 mm, the elongation at break was 171%, and the tensile strength was 8 MPa. This indicates that not applying topcoat significantly affects the corresponding performance of the color steel plate coating. The various components in the topcoat mix with each other and work together to improve the mechanical properties, wear resistance, environmental friendliness, and adhesion of the topcoat coating.

[0147] Comparative Example 3 primer without modified attapulgite showed the following results as shown in Table 1: surface drying time 35 min, complete drying time 16 h, film adhesion grade 1, impact resistance 44 cm·kg, peel strength at 180℃ 0.25 N / 25 mm, elongation at break 180%, and tensile strength 9 MPa.

[0148] Comparative Example 2, without topcoat, showed in Table 1 that the surface drying time was 17 min, the actual drying time was 9 h, the film adhesion was grade 2, the impact resistance was 41 cm·kg, the peel strength at 180℃ was 0.20 N / 25 mm, the elongation at break was 171%, and the tensile strength was 8 MPa. This indicates that the modified attapulgite can adjust the viscosity of the system, increase the gloss, mechanical properties, abrasion resistance, and weather resistance of the primer, and slow down the flow rate of the system, thereby forming a more uniform primer coating. Moreover, the modified attapulgite can firmly adhere to the steel plate surface, increasing the adhesion between the system and the steel plate.

[0149] In Comparative Example 4, attapulgite was used instead of modified attapulgite in the primer. As shown in Table 1, the surface drying time was 30 min, the actual drying time was 12 h, the film adhesion was grade 1, the impact resistance was 46 cm·kg, the peel strength at 180℃ was 0.30 N / 25 mm, the elongation at break was 190%, and the tensile strength was 11 MPa. This indicates that the modified attapulgite prepared in this application has excellent mechanical and adhesive properties, and can be subsequently used in primer coatings to improve the corresponding properties of the primer coating.

[0150] Comparative Example 5, without the addition of modified bamboo charcoal powder to the topcoat, showed in Table 1 that the surface drying time was 37 min, the actual drying time was 16 h, the film adhesion was grade 1, the impact resistance was 42 cm·kg, the peel strength at 180℃ was 0.22 N / 25 mm, the elongation at break was 185%, and the tensile strength was 8 MPa. This indicates that the modified bamboo charcoal powder has porous and easily absorbent properties and mechanical strength, and can form a powerful purification filter on the surface of the topcoat coating, capturing harmful substances such as formaldehyde and VOCs in the board in all directions, making the topcoat coating more environmentally friendly and with better mechanical properties.

[0151] In Comparative Example 6, an equal amount of bamboo charcoal powder was used to replace the modified bamboo charcoal powder in the topcoat. As shown in Table 1, the surface drying time was 30 min, the actual drying time was 12 h, the film adhesion was grade 1, the impact resistance was 47 cm·kg, the peel strength at 180℃ was 0.31 N / 25 mm, the elongation at break was 192%, and the tensile strength was 12 MPa. This indicates that the modified bamboo charcoal powder prepared in this application has excellent mechanical and adhesive properties, and can be subsequently applied to topcoat coatings to improve the corresponding properties of the topcoat coating.

[0152] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A manufacturing process for environmentally friendly color-coated steel sheets, characterized in that, Includes the following steps: (1) Degrease and clean the steel plate at a temperature of 80-85℃ for 20-25 minutes, then apply primer, bake at a temperature of 95-100℃, and dry with hot air to obtain the treated steel plate. (2) Coat the steel plate treated in step (1) with topcoat, bake it at a temperature of 95-100℃, and dry it with hot air to obtain an environmentally friendly color steel plate. The raw material components of the primer, by weight, include the following components: 16-24 parts waterborne epoxy resin, 1-3 parts sodium hydroxide, 5-10 parts modified attapulgite, 30-40 parts deionized water, 0.5-1.5 parts lauryl alcohol, 1.5-2 parts polyacrylic acid-based dispersant, 0.4-0.8 parts silicone defoamer, 20-25 parts acrylic emulsion, and 1.5-2.5 parts dodecyl alcohol ester; the raw material components of the topcoat include the following components: water-soluble saturated polyester resin, water-soluble amino resin, modified bamboo charcoal powder, cellulose acetate butyrate, carbon fiber, nano silver, dispersant BYK-104S, ethylene glycol butyl ether, and deionized water; The method for preparing the modified bamboo charcoal powder includes the following steps: (1) Disperse bamboo charcoal powder in sodium hydroxide solution, stir at 80-85℃ for 1-2 hours, wash with water, and calcine at 350-400℃ for 2-3 hours to obtain treated bamboo charcoal powder; (2) Disperse nano-titanium dioxide in an ethanol solution of monolaurate glycerol and dry to obtain treated nano-titanium dioxide; (3) Disperse the bamboo charcoal powder treated in step (1) in deionized water, stir at 4-10℃ for 10-20 min, then add the nano titanium dioxide treated in step (2), add modified sodium alginate, stir for 1-2 h, filter and dry to obtain modified bamboo charcoal powder. The method for preparing the modified sodium alginate includes the following steps: dispersing sodium alginate in deionized water, adding triethylenediamine and epichlorohydrin, stirring at room temperature for 1-2 hours, then adding xanthan gum, and continuing to stir to obtain modified sodium alginate. The method for preparing the modified attapulgite includes the following steps: (1) Disperse the attapulgite in anhydrous ethanol, dry it, add sodium silicate, stir at 80-85℃ for 2-3 hours, filter and dry it to obtain the treated attapulgite. (2) Disperse hollow ZnO microspheres in anhydrous ethanol, add graphene oxide, ultrasonically disperse for 2-3 h, then heat at 150-160℃ for 20-24 h, wash with water and dry to obtain the treated hollow ZnO microspheres; (3) Disperse the attapulgite treated in step (1) in anhydrous ethanol, add the hollow ZnO microspheres treated in step (2), stir for 2-3 hours, filter and dry to obtain modified attapulgite.

2. The manufacturing process of an environmentally friendly color steel sheet according to claim 1, characterized in that, The raw material components of the topcoat, by weight, include the following components: 50-60 parts of water-soluble saturated polyester resin, 8-12 parts of water-soluble amino resin, 12-15 parts of modified bamboo charcoal powder, 6-9 parts of cellulose acetate butyrate, 4-8 parts of carbon fiber, 1-3 parts of nano silver, 2-2.5 parts of dispersant BYK-104S, 3-5 parts of ethylene glycol butyl ether, and 10-15 parts of deionized water.

3. The manufacturing process of an environmentally friendly color steel plate according to claim 1, characterized in that, The mass ratio of bamboo charcoal powder, nano titanium dioxide, and modified sodium alginate is 1:0.4-0.7:0.06-0.

09.

4. The manufacturing process of an environmentally friendly color steel plate according to claim 1, characterized in that, The mass ratio of the attapulgite clay, hollow ZnO microspheres, and graphene oxide is 1g:0.2-0.5g:0.07-0.09mg.

5. The manufacturing process of an environmentally friendly color steel sheet according to claim 1, characterized in that, The hollow ZnO microspheres have a particle size of 50-70 nm and a shell thickness of 30-70 nm.

6. The manufacturing process of an environmentally friendly color steel plate according to claim 1, characterized in that, In step (1), degreasing solution is used for degreasing and cleaning. The thickness of the primer is 20-30μm and the thickness of the topcoat is 40-50μm.

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