Anti-fading packaging box with anti-oxidation coating and preparation process

Abstract

The invention relates to the field of coatings, and specifically discloses an anti-fading packaging box with an antioxidant coating and a preparation process thereof; the preparation process of the anti-fading packaging box comprises the following steps: spraying an antioxidant coating on the surface of the packaging box, drying at room temperature to obtain an antioxidant coating; spraying a cross-linking aid solution; spraying a hydrophobic coating to obtain a hydrophobic coating; heating and curing to obtain an anti-fading packaging box; the antioxidant coating comprises: an epoxy resin, an antioxidant, a curing agent, and a solvent; the cross-linking aid solution is a solution containing a curing agent; the hydrophobic coating comprises: an epoxy resin, a hydrophobic filler, a curing agent, and a solvent; the thickness of the antioxidant coating is 25 to 35 μm; the spraying amount of the cross-linking aid solution is 15 to 20 g / m 2 ; The thickness of the hydrophobic coating is 8 to 12 μm; the room temperature drying time is 1 to 1.5 hours; the curing process is: curing at 80 to 90°C for 2 to 3 hours and curing at 120 to 130°C for 4 to 6 hours.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular discloses an anti-discoloration packaging box with an anti-oxidation coating and a preparation process thereof. Background Art

[0002] The packaging box has the functions of enhancing brand image, promoting sales, conveying information, and enhancing product attractiveness. Its color is part of the brand image and one of the important factors for consumers to identify and choose products. Therefore, the anti-fading property of the packaging box is crucial.

[0003] There are many reasons for the discoloration of packaging boxes, including physical wear, oxidation reaction, the influence of ultraviolet rays or water vapor in the environment, etc. The existing technology often sprays a layer of coating on the surface of the packaging box to achieve the effect of anti-discoloration, but these coatings often cannot take into account the characteristics of anti-oxidation, anti-ultraviolet, and hydrophobicity, or often have low light transmittance, which affects the color of the packaging box itself; therefore, it is of great significance to study an anti-discoloration packaging box with the above characteristics and high transparency. Summary of the invention

[0004] The object of the present invention is to provide an anti-discoloration packaging box with an anti-oxidation coating and a preparation process to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A preparation process of an anti-fading packaging box with an anti-oxidation coating: comprising the following steps: spraying an anti-oxidation coating on the surface of the packaging box, drying at room temperature to obtain an anti-oxidation coating; spraying a cross-linking solution; spraying a hydrophobic coating to obtain a hydrophobic coating; heating and curing to obtain an anti-fading packaging box;

[0006] The anti-oxidation coating comprises: epoxy resin, antioxidant, curing agent (m-xylene diamine), and solvent (xylene);

[0007] The auxiliary cross-linking solution is a solution containing a curing agent;

[0008] The hydrophobic coating comprises: epoxy resin, hydrophobic filler, curing agent (m-xylene diamine), and solvent (xylene).

[0009] More optimally, the cross-linking aid solution includes a curing agent and a solvent, and the amount of the curing agent m-xylene diamine added is 20-30 wt % of the solvent xylene.

[0010] More optimally, the cross-linking aid solution includes a curing agent and a solvent, and the amount of the curing agent m-xylene diamine added is 25 wt % of the solvent xylene.

[0011] More optimally, the thickness of the anti-oxidation coating is 25 to 35 μm; the spraying amount of the cross-linking solution is 15 to 20 g / m2; and the thickness of the hydrophobic coating is 8 to 12 μm.

[0012] More optimally, the preparation of the antioxidant includes the following steps: taking cyanuric chloride and xylene, mixing them evenly, slowly adding N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stirring, dropping sodium hydroxide aqueous solution, reacting at 70-75°C for 10-12h; adding 1-aminobenzotriazole, heating to 100-110°C and reacting for 10-12h; adding terminal amino silicone oil, filling with nitrogen to replace the air, pressing 0.5MPa, stirring and heating to 165-170°C, raising the pressure to 1.0MPa, reacting for 10-12h, reducing the temperature to 130-140°C, adding diglycidyl ether, reacting for 3-4h, reducing the temperature to room temperature, removing the solvent, separating the liquids, taking the organic phase, washing with water, and drying to obtain the antioxidant.

[0013] More optimally, the antioxidant includes the following raw materials, calculated by mass: 15 to 20 parts of cyanuric chloride, 150 to 200 parts of xylene; the molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1::(0.8 to 1):(0.8 to 1):(0.8 to 1.5):(1 to 2).

[0014] More optimally, the amino-terminated silicone oil is CHEERSIL81104 type, and the amino content is 2.0±0.05mmol / g.

[0015] More optimally, the preparation of the hydrophobic filler includes the following steps: taking nano-silica, modifying it with an aminosilane coupling agent to obtain modified silica; taking the modified silica, adding dimethyl sulfoxide, adding 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stirring at 50-60°C for 1-2h, adding 1,6-hexanediol diglycidyl ether, heating to 110-120°C and stirring for 3-4h to obtain a hydrophobic filler.

[0016] More optimally, the hydrophobic filler includes the following raw materials, calculated by weight: 10 to 15 parts of modified silica, 60 to 80 parts of dimethyl sulfoxide, 1 to 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, and 2 to 3 parts of 1,6-hexanediol diglycidyl ether.

[0017] More optimally, the preparation method of the modified silica is: take 10 to 15 parts of nano-silica, 30 to 40 parts of water, 70 to 100 parts of ethanol, and 1 to 2 parts of aminosilane coupling agent, heat to 40 to 50° C., stir for 4 to 6 hours, filter out the solid, and dry to obtain the modified silica.

[0018] More optimally, the preparation method of the modified silica is: take 15 parts of nano-silica, 40 parts of water, 90 parts of ethanol, and 2 parts of aminosilane coupling agent, heat to 50° C. and stir for 6 hours, filter out the solid, and dry to obtain the modified silica.

[0019] More optimally, the anti-oxidation coating comprises the following raw materials, calculated by weight: 100 parts of epoxy resin, 15 to 20 parts of antioxidant, 10 to 15 parts of curing agent, and 80 parts of solvent.

[0020] More optimally, the hydrophobic coating comprises the following raw materials, calculated by weight: 100 parts of epoxy resin, 20 to 30 parts of hydrophobic filler, 10 to 15 parts of curing agent, and 80 parts of solvent.

[0021] More optimally, the room temperature drying time is 1 to 1.5 hours; the curing process is: curing at 80 to 90° C. for 2 to 3 hours, and curing at 120 to 130° C. for 4 to 6 hours.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the surface of the packaging box has an anti-oxidation coating and a hydrophobic coating; a protective film is formed, so that the colored coating on the surface of the packaging box is not easy to fall off and can resist oxidation; an antioxidant is added to the anti-oxidation coating, which is composed of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino-terminated silicone oil, and diglycidyl ether, wherein N-butyl-2,2,6,6-tetramethyl-4-piperidinamine contains a hindered amine structure and is an excellent light stabilizer and antioxidant, and is used together with 1-aminobenzotriazole having ultraviolet absorption ability to achieve good ultraviolet resistance. External, antioxidant effect; when the molecular weight is small, the compatibility of the additive with the epoxy resin matrix is ​​poor, and it is easy to have migration problems, which affects the performance and the transparency of the epoxy resin; therefore, the introduction of amino silicone oil contains multiple Si-O bonds with higher bond energy, which further improves the UV resistance and also increases the molecular weight of the antioxidant; finally, the introduction of diglycidyl ether introduces epoxy groups into the antioxidant to improve its compatibility with the epoxy resin; due to the improvement of compatibility, the transparency of the epoxy resin matrix is ​​also guaranteed; this layer has excellent antioxidant and UV protection functions, and can protect the colored coating of the packaging box from falling off and fading;

[0023] The hydrophobic coating includes a hydrophobic filler. First, nano-silica is modified with an aminosilane coupling agent, and then the surface amino group is used to introduce 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, which contains fluorine elements and greatly improves the hydrophobicity. 1,6-hexanediol diglycidyl ether is also introduced, which has good compatibility with the epoxy resin matrix and has a diluting effect, which helps to improve the transparency. This layer has good hydrophobicity and wear resistance, and improves the anti-fouling, moisture-proof and durability of the packaging box.

[0024] The thickness of the two layers of coating needs to be controlled. Too thin will result in insufficient performance, while too thick will affect transparency and the color of the packaging box itself.

[0025] If antioxidants and hydrophobic fillers are added to epoxy resin at the same time and only one coating is sprayed, the large amount of additives will cause dispersibility and compatibility problems, resulting in a decrease in the transparency of the resin matrix;

[0026] After the anti-oxidation coating is sprayed, it is dried at room temperature, and then a cross-linking solution and a hydrophobic coating are sprayed in sequence, and finally heated together for curing. This method makes the curing more uniform, ensures transparency, and makes the two coatings closely bonded, thereby improving the quality of the packaging box. DETAILED DESCRIPTION

[0027] The following is a preferred implementation of the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. For ordinary technicians in this technical field, all other embodiments obtained by ordinary technicians in this field without creative work without departing from the principle of the embodiment of the present invention are within the scope of protection of the present invention.

[0028] The following parts are by mass unless otherwise specified;

[0029] Example 1: S1: Take 18 parts of cyanuric chloride and 180 parts of xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0030] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:1:1:1.2;

[0031] S2: Take 100 parts of epoxy resin, 18 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0032] S3: Take 12 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0033] S4: Take 100 parts of epoxy resin, 25 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0034] S5: Spray the antioxidant coating onto the surface of the packaging box and dry it at room temperature for 1 hour with a thickness of 30 μm to obtain an antioxidant coating; spray the cross-linking solution on the outside of the antioxidant coating with a spraying amount of 18 g / m 2 ; Spray the hydrophobic coating with a thickness of 10 μm to obtain a hydrophobic coating, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain an anti-fading packaging box.

[0035] Example 2: S1: Take 20 parts of cyanuric chloride and 180 parts of xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0036] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:0.8:1.5:1.5;

[0037] S2: Take 100 parts of epoxy resin, 15 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0038] S3: Take 15 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0039] S4: Take 100 parts of epoxy resin, 30 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0040] S5: Spray the antioxidant coating onto the surface of the packaging box and dry it at room temperature for 1 hour with a thickness of 30 μm to obtain an antioxidant coating; spray the cross-linking solution on the outside of the antioxidant coating with a spraying amount of 18 g / m 2 ; Spray the hydrophobic coating with a thickness of 10 μm to obtain a hydrophobic coating, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain an anti-fading packaging box.

[0041] Example 3: S1: Take 20 parts of cyanuric chloride and 180 parts of xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0042] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:0.8:1:2;

[0043] S2: Take 100 parts of epoxy resin, 20 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0044] S3: Take 10 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 2 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0045] S4: Take 100 parts of epoxy resin, 20 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0046] S5: Spray the antioxidant coating onto the surface of the packaging box and dry it at room temperature for 1 hour with a thickness of 30 μm to obtain an antioxidant coating; spray the cross-linking solution on the outside of the antioxidant coating with a spraying amount of 18 g / m 2 ; Spray the hydrophobic coating with a thickness of 10 μm to obtain a hydrophobic coating, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain an anti-fading packaging box.

[0047] Comparative Example 1 (changing the coating thickness, the remaining method steps are consistent with Example 1): S1: Take 18 parts of cyanuric chloride and 180 parts of xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0048] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:1:1:1.2;

[0049] S2: Take 100 parts of epoxy resin, 18 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0050] S3: Take 12 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0051] S4: Take 100 parts of epoxy resin, 25 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0052] S5: Spray the antioxidant coating onto the surface of the packaging box and dry it at room temperature for 1 hour with a thickness of 20 μm to obtain an antioxidant coating; spray the cross-linking solution on the outside of the antioxidant coating with a spraying amount of 18 g / m 2 ; Spray the hydrophobic coating with a thickness of 20 μm to obtain a hydrophobic coating, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain an anti-fading packaging box.

[0053] Comparative Example 2 (without using a co-crosslinking solution and changing the curing method, the remaining method steps are consistent with Example 1): S1: Take 18 parts of cyanuric chloride and 180 parts of xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0054] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:1:1:1.2;

[0055] S2: Take 100 parts of epoxy resin, 18 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0056] S3: Take 12 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0057] S4: Take 100 parts of epoxy resin, 25 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0058] S5: Spray the antioxidant coating onto the surface of the packaging box, cure at 80°C for 3h and at 120°C for 5h to obtain an antioxidant coating with a thickness of 30μm; spray the hydrophobic coating with a thickness of 10μm to obtain a hydrophobic coating, cure at 80°C for 3h and at 120°C for 5h to obtain an anti-fading packaging box.

[0059] Comparative Example 3 (adding a hydrophobic filler to an antioxidant coating, using a single coating, and the remaining method steps are consistent with Example 1): S1: Take 18 parts of cyanuric chloride and 180 parts of xylene, mix well, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir for 2 hours, drop sodium hydroxide aqueous solution (8g sodium hydroxide, 20mL water), and react at 70°C for 10 hours; add 1-aminobenzotriazole, heat to 110°C and react for 12 hours, add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 170°C, increase the pressure to 1.0MPa, react for 10 hours, reduce to 130°C, add diglycidyl ether, react for 4 hours, reduce to room temperature, separate, evaporate the solvent under reduced pressure, add ethyl acetate, separate, take the organic phase, wash the organic phase with water twice, and dry to obtain an antioxidant;

[0060] The molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, amino group in amino-terminated silicone oil, and diglycidyl ether is 1:1:1:1:1.2;

[0061] S2: Take 12 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler; take 100 parts of epoxy resin, 18 parts of antioxidant, 25 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix well to obtain a coating;

[0062] S3: Spray the coating onto the surface of the packaging box, dry at room temperature for 1 hour, thickness 30 μm, spray the cross-linking solution, spraying amount 18 g / m 2 ; Spray the coating with a thickness of 10 μm, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain a discoloration-resistant packaging box.

[0063] Comparative Example 4 (the preparation method of the antioxidant was changed, and the remaining steps were consistent with those of Example 1): S1: 18 parts of cyanuric chloride and 180 parts of xylene were taken, mixed evenly, and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine was slowly added in an ice-water bath, stirred for 2 hours, and a sodium hydroxide aqueous solution (8 g of sodium hydroxide, 20 mL of water) was added dropwise, and the reaction was carried out at 70° C. for 10 hours; water and ethyl acetate were added to extract 3 times, the organic phase was taken, dried, and the solvent was removed to obtain an antioxidant;

[0064] The molar ratio of cyanuric chloride to N-butyl-2,2,6,6-tetramethyl-4-piperidinamine is 1:3;

[0065] S2: Take 100 parts of epoxy resin, 18 parts of antioxidant, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain an antioxidant coating;

[0066] S3: Take 12 parts of modified silica, add 70 parts of dimethyl sulfoxide, add 2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stir at 60°C for 2 hours, add 3 parts of 1,6-hexanediol diglycidyl ether, heat to 120°C and stir for 4 hours to obtain a hydrophobic filler;

[0067] S4: Take 100 parts of epoxy resin, 25 parts of hydrophobic filler, 12 parts of curing agent, and 80 parts of xylene, mix them evenly, and obtain a hydrophobic coating;

[0068] S5: Spray the antioxidant coating onto the surface of the packaging box and dry it at room temperature for 1 hour with a thickness of 30 μm to obtain an antioxidant coating; spray the cross-linking solution on the outside of the antioxidant coating with a spraying amount of 18 g / m 2 ; Spray the hydrophobic coating with a thickness of 10 μm to obtain a hydrophobic coating, cure at 80°C for 3 hours and at 120°C for 5 hours to obtain an anti-fading packaging box.

[0069] In the above examples, the test methods used are conventional methods unless otherwise specified; the raw materials used are commercially available unless otherwise specified, and the sources of the raw materials are as follows: m-phenylenediamine (CAS: 1477-55-0); ethyl acetate (CAS: 141-78-6); cyanuric chloride (CAS: 108-77-0); xylene (CAS: 1330-20-7); N-butyl-2,2,6,6-tetramethyl-4-piperidinamine (JS0065, Hubei Jusheng Technology Co., Ltd.); 1-aminobenzotriazole (S62316, Shanghai Yuanye); amino-terminated silicone oil (CHEERSIL81 104, Wuhan Chujiang Haoyu Chemical Technology Development Co., Ltd.); diglycidyl ether (CAS: 2238-07-5); epoxy resin (E51, Jiader); nano-silica (ML-SiO2-N07, Zhejiang Manli Nanotechnology Co., Ltd.); ethanol (CAS: 64-17-5); aminosilane coupling agent (KH550, CAS: 919-30-2); dimethyl sulfoxide (CAS: 67-68-5); 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde (CAS: 881674-56-2); 1,6-hexanediol diglycidyl ether (CAS: 16096-31-4).

[0070] Experiment: Take the coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4, spray them on the mold and cure them according to the methods of Examples 1 to 3 and Comparative Examples 1 to 4, and take them out to obtain samples; (1) Use SL200B contact angle meter to test the surface water contact angle; (2) Refer to GBT14522-2008, artificial accelerated aging for 1000h, and test the gloss retention rate (referring to the ability of the coating to maintain its original gloss when exposed to light, reflecting the ability of the coating to resist external factors such as ultraviolet radiation, chemical oxidation, etc.); (3) Use UV-3600 ultraviolet visible spectrophotometer to test the light transmittance at 500nm; specific data are shown in the table below;

[0071]

[0072] Conclusion: In comparative example 1, the coating thickness is changed, and the light retention rate and light transmittance decrease significantly, which shows that the thickness needs to be controlled; in comparative example 2, no auxiliary cross-linking solution is used, the antioxidant coating is first cured, and then the hydrophobic coating is sprayed for curing, and the resulting performance is not as good as that in the embodiment; in comparative example 3, a hydrophobic filler is added to the antioxidant coating, and the performance is reduced due to compatibility problems caused by the addition of more auxiliaries and fillers; in comparative example 4, the preparation method of the antioxidant is changed, and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and terminal amino silicone oil are not added, and the performance is reduced; in summary, the surface coating of the anti-fading packaging box prepared by the present invention has good light transmittance, light retention rate and hydrophobicity, and can protect the surface coating of the packaging box to achieve the purpose of anti-fading.

[0073] Finally, it should be noted that the above is only a preferred embodiment of the present invention, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the spirit and principle of the present invention and within the technical scope disclosed in this application should be included in the protection scope of this application; in the absence of conflict, the embodiments of this application and the features in the embodiments can be combined with each other. Therefore, the protection scope of this application shall be based on the protection scope of the claims.

Claims

1. A process for preparing an anti-fading packaging box with an antioxidant coating, characterized in that: The following steps are involved: S1: Take cyanuric chloride and xylene, mix them evenly, slowly add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine in an ice-water bath, stir, add sodium hydroxide aqueous solution dropwise, react at 70-75°C for 10-12h; add 1-aminobenzotriazole, heat to 100-110°C and react for 10-12h; add amino-terminated silicone oil, fill with nitrogen to replace the air, press 0.5MPa, stir and heat to 165-170°C, increase the pressure to 1.0MPa, react for 10-12h, reduce to 130-140°C, add diglycidyl ether, react for 3-4h, reduce to room temperature, remove solvent, separate, take organic phase, wash with water, dry to obtain antioxidant; S2: Spray the anti-oxidation coating on the surface of the packaging box and dry it at room temperature for 1 to 1.5 hours to obtain an anti-oxidation coating; S3: spraying a cross-linking solution on the antioxidant coating; Spraying hydrophobic coating to obtain a hydrophobic coating; curing at 80-90°C for 2-3 hours and at 120-130°C for 4-6 hours to obtain an anti-fading packaging box; The anti-oxidation coating comprises the following raw materials, calculated by weight: 100 parts of epoxy resin, 15-20 parts of antioxidant, 10-15 parts of curing agent, and 80 parts of solvent; The hydrophobic coating comprises the following raw materials, calculated by mass: 100 parts of epoxy resin, 20-30 parts of hydrophobic filler, 10-15 parts of curing agent, and 80 parts of solvent; The auxiliary cross-linking solution includes a curing agent and a solvent, and the amount of the curing agent added is 20-30wt% of the solvent; The antioxidant comprises the following raw materials, calculated by mass: 15-20 parts of cyanuric chloride and 150-200 parts of xylene; the molar ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, 1-aminobenzotriazole, the amino group in the amino-terminated silicone oil, and diglycidyl ether is 1: (0.8-1): (0.8-1: (0.8-1.5): (1-2).

2. The process for preparing a discoloration-resistant packaging box with an anti-oxidation coating according to claim 1, characterized in that: The thickness of the anti-oxidation coating is 25-35 μm; The spraying amount of the cross-linking solution is 15~20g / m 2 ; The thickness of the hydrophobic coating is 8~12μm.

3. The process for preparing a discoloration-resistant packaging box with an anti-oxidation coating according to claim 1, characterized in that: The preparation of the hydrophobic filler comprises the following steps: taking nano-silica, modifying it with an aminosilane coupling agent to obtain modified silica; taking the modified silica, adding dimethyl sulfoxide, adding 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, stirring at 50-60° C. for 1-2 hours, adding 1,6-hexanediol diglycidyl ether, heating to 110-120° C. and stirring for 3-4 hours to obtain the hydrophobic filler.

4. The process for preparing a discoloration-resistant packaging box with an anti-oxidation coating according to claim 3, characterized in that: The hydrophobic filler comprises the following raw materials, calculated by weight: 10-15 parts of modified silicon dioxide, 60-80 parts of dimethyl sulfoxide, 1-2 parts of 5-(2-fluorophenyl)pyrrole-3-carboxaldehyde, and 2-3 parts of 1,6-hexanediol diglycidyl ether.

5. An anti-fading packaging box obtained according to the preparation process of an anti-fading packaging box with an antioxidant coating according to any one of claims 1 to 4.

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