Surface waterproof ink printing process for corrugated carton

Abstract

The invention discloses a surface waterproof ink printing process for a corrugated carton, and relates to the technical field of waterproof ink. The preparation method comprises the following steps: step 1, sequentially adding polyurethane emulsion, color paste, isopropanol, a photoinitiator, a defoaming agent and a flatting agent into deionized water, and stirring and homogenizing to obtain waterproof ink; and 2, dedusting the surface of the corrugated carton, printing the waterproof ink on the surface of the corrugated carton, and carrying out ultraviolet irradiation and hot drying to obtain a printed finished product. The waterproof ink is prepared from the following raw material components in parts by weight: 52 to 58 parts of polyurethane emulsion, 8 to 12 parts of silicon-boron oligomer, 8 to 12 parts of color paste, 8 to 10 parts of isopropanol, 0.01 to 0.02 part of photoinitiator, 0.2 to 0.5 part of defoaming agent, 08 to 1 part of flatting agent and 10 to 12 parts of deionized water. A printed finished product obtained by the surface waterproof ink printing process has good adhesive force, waterproofness and wear resistance.

Description

Technical Field

[0001] The invention relates to the field of waterproof ink, in particular to a surface waterproof ink printing process for a corrugated paper box. Background Art

[0002] Corrugated boxes are a common consumable material used to protect goods and facilitate storage and transportation. Generally, patterns are printed on their surface to clarify the goods or beautify and promote the goods. At present, with the rapid development of logistics and e-commerce industries, the demand for corrugated boxes is gradually increasing, and the requirements for their performance and printing quality are also increasing.

[0003] In the prior art, traditional corrugated paperboards use solvent-based inks. As people's environmental awareness increases and they pay more attention to human health, water-based inks are gradually used. The ideal waterproof ink printing process should have good adhesion, wear resistance and drying speed to ensure the clarity and durability of the printed pattern. However, common water-based inks are often used as connectors because polyurethane has good adhesion to materials such as paper, but its water resistance and heat resistance are poor, and its mechanical properties such as surface wear resistance still need to be further improved.

[0004] In summary, it is of great significance to solve or improve the above problems and form a surface waterproof ink printing process for corrugated paper boxes. Summary of the invention

[0005] The purpose of the present invention is to provide a surface waterproof ink printing process for corrugated paper boxes to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A surface waterproof ink printing process for a corrugated paper box comprises the following steps: Step 1: Add polyurethane emulsion, silicon boron oligomer, color paste, isopropyl alcohol, photoinitiator and defoamer into deionized water in sequence, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on the surface, irradiate with ultraviolet light and heat dry to obtain a printed product.

[0007] More optimally, the raw materials of the waterproof ink include the following components: by weight, 52 to 58 parts of polyurethane emulsion, 8 to 12 parts of silicon boron oligomer, 8 to 12 parts of color paste, 8 to 10 parts of isopropyl alcohol, 0.01 to 0.02 parts of photoinitiator, 0.2 to 0.5 parts of defoaming agent, and 10 to 12 parts of deionized water.

[0008] Preferably, the parameters of the ultraviolet light are: the light intensity is 100-200 mW / cm 2 , time is 8~15 minutes; the temperature of the hot drying is 60~80℃.

[0009] More optimally, the preparation method of the polyurethane emulsion is: After vacuum dehydration, polytetramethylene ether glycol and tetrafluorobutanediol are mixed evenly with isophorone diisocyanate and dibutyltin dilaurate, and the temperature is raised to 70-80°C for reaction for 2-3 hours; an acetone mixed solution containing 1,4-butanediol, modified polyethylene wax and modified titanium dioxide is added, and the reaction is continued with stirring for 1-1.5 hours; trimethylolpropane tris(3-mercaptopropionic acid) is added, and the reaction is stirred for 1-2 hours; acetone is evaporated; allyl polyethylene glycol ether and deionized water are added for emulsification to obtain a polyurethane emulsion with a solid content of 30-35wt%.

[0010] More optimally, the polyurethane emulsion comprises the following components: by weight, 80 to 85 parts of polytetramethylene ether glycol, 10 to 15 parts of tetrafluorobutanediol, 50 to 60 parts of isophorone diisocyanate, 0.2 to 0.5 parts of dibutyltin dilaurate, 2 to 3 parts of 1,4-butanediol, 4 to 6 parts of modified polyethylene wax, 3 to 5 parts of modified titanium dioxide, 20 to 25 parts of hydroxymethylpropane tris(3-mercaptopropionate), and 0.5 to 1 part of allyl polyethylene glycol ether.

[0011] More optimally, the preparation method of the modified titanium dioxide is: adding titanium dioxide to an acetone solvent and dispersing it evenly, adding isophorone diisocyanate, stirring for 1 to 2 hours, leaving it for 2 to 6 hours, filtering, and heat drying to obtain modified titanium dioxide; wherein the mass ratio of titanium dioxide to isophorone diisocyanate is 1:0.2~0.3.

[0012] More optimally, the preparation method of the polyethylene wax emulsion is: polyethylene wax, tert-butyl peroxide, and 2-methyl-2-propylene-1-ol are added to benzene in sequence, the temperature is raised to 80-85°C, and the mixture is stirred and reacted for 2-3 hours, filtered, washed, and dried to obtain modified polyethylene wax; wherein the mass ratio of polyethylene wax, tert-butyl peroxide, and 2-methyl-2-propylene-1-ol is 10:0.05:1-3.

[0013] More optimally, the preparation method of the silicon boron oligomer is: add boric acid, 3,5-difluorophenylboric acid, 3-glycidyl propyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7~0.8:0.2~0.3:0.6~0.8:1.2~1.4 in turn to diethylene glycol dimethyl ether solvent, and stir the reaction at 150~160°C for 2~3 hours; flash off the solvent and by-products; and freeze-dry to obtain the silicon boron oligomer.

[0014] More optimally, a printed product is obtained by a surface waterproof ink printing process for a corrugated paper box.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: in the scheme, by specifically introducing fluorine-containing segments into the polyurethane emulsion; and cooperating with silicon boron oligomers to effectively improve the adhesion, water resistance and wear resistance of the waterproof ink, the printing quality of the waterproof ink is comprehensively improved.

[0016] In the (1) scheme, polyurethane emulsion is used as a linker in waterproof ink, and the related substances in the preparation process of polyurethane emulsion are limited, which effectively improves the printing performance of waterproof ink. Specifically, the introduction of tetrafluorobutanediol chain segments into the polyurethane main chain effectively improves the hydrophobicity of polyurethane, and the introduction amount of the chain segments is limited, thereby effectively ensuring its emulsion dispersibility and interface adhesion.

[0017] Among them, modified polyethylene wax and modified titanium dioxide are introduced in the chain extension process; organic and inorganic particles are used to effectively improve the heat resistance and wear resistance of waterproof ink, which can effectively improve the smoothness and leveling of the waterproof film layer, and further improve the printing quality. In addition, since both substances have light scattering properties, the Rayleigh scattering effect between the two substances can be used to effectively promote the photocrosslinking of waterproof ink, effectively improve the cohesion and crosslinking degree, and improve the adhesion and waterproofness. And pre-photocrosslinking can effectively improve the clarity of the pattern before drying. Among them, compared with the common introduction of polyethylene wax and nanoparticles as additives, the modified polyethylene wax used in this application is to use peroxide to initiate the grafting of 2-methyl-2-propylene-1-ol and use isophorone diisocyanate to modify the surface of titanium dioxide. Both can be pre-dispersed and grafted in the polyurethane emulsion, which has a lower impact on the comprehensive properties of the waterproof ink such as viscosity, and has good dispersion uniformity; a better waterproof ink printing surface can be produced. It should be noted that the amount of the two substances introduced needs to be limited. Too high will affect the performance of the polyurethane emulsion itself, thereby affecting the comprehensiveness of printing.

[0018] Among them, trimethylolpropane tris(3-mercaptopropionic acid) ester is used as a capping agent for polyurethane, so that the polyurethane contains reactive amino and mercapto groups, and the cross-linking of silicon boron oligomers effectively forms a double cross-linked network, improves the toughness of the printed ink layer and other mechanical properties, and effectively improves the adhesion and wear resistance of the coating.

[0019] (2) In the scheme, silicon boron oligomers are introduced to promote the double network crosslinking of the linker polyurethane emulsion, and synergistically improve the printing performance of the waterproof ink. Specifically, boric acid, 3,5-difluorophenylboric acid, 3-glycidyl propyl ether trimethoxysilane, and vinyl trimethoxysilane are used as raw materials, and polycondensation is performed to form silicon boron oligomers containing vinyl and epoxy groups. It can form crosslinks with the thiol and amino groups in the polyurethane to form a double network crosslinking network, which effectively promotes the toughness of the ink and improves the wear resistance. At the same time, the 3,5-difluorophenylboric acid chain segment further assists the polyurethane to improve the waterproof performance, and effectively improves the clarity and durability of the printed ink layer in a humid environment. In addition, the organosilicon substance can effectively enhance the thermal stability and adhesion of the waterproof ink. In this way, the overall performance of the waterproof ink is effectively improved in combination with the linker. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0021] It should be noted that there are no special restrictions on the purchase manufacturers of all raw materials involved in the present invention, which exemplarily include: in the following embodiments, titanium dioxide is nano-grade, model YC-YTR03, the model of polyethylene wax is AC-6, and the color paste is Lithol Red BK; the above and other raw materials involved are commercially purchased. Example 1

[0022] A surface waterproof ink printing process for a corrugated paper box comprises the following steps: Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyethylene glycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0023] Step 1: Add 55 parts of polyurethane emulsion, 10 parts of silicon boron oligomer, 10 parts of color paste, 10 parts of isopropyl alcohol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence by weight, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product. Example 2

[0024] A surface waterproof ink printing process for a corrugated paper box comprises the following steps: Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyethylene glycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0025] Step 1: Add 52 parts of polyurethane emulsion, 8 parts of silicon boron oligomer, 8 parts of color paste, 10 parts of isopropyl alcohol, 0.01 parts of photoinitiator 500, and 0.2 parts of defoamer KSZ-108 to 12 parts of deionized water in sequence by weight, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product. Example 3

[0026] A surface waterproof ink printing process for a corrugated paper box comprises the following steps: Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyethylene glycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0027] Step 1: Add 58 parts of polyurethane emulsion, 12 parts of silicon boron oligomer, 12 parts of color paste, 8 parts of isopropyl alcohol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product.

[0028] Comparative Example 1: Modified titanium dioxide was introduced into the polyurethane emulsion alone, and the rest was the same as in Example 1; Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of titanium dioxide and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyglycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0029] Step 1: Add 55 parts of polyurethane emulsion, 10 parts of silicon boron oligomer, 10 parts of color paste, 10 parts of isopropyl alcohol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence by weight, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product.

[0030] Comparative Example 2: The amount of modified polyethylene wax introduced into the polyurethane emulsion was increased, and the rest was the same as in Example 1; Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to the weight percentage, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 10 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyglycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0031] Step 1: Add 55 parts of polyurethane emulsion, 10 parts of silicon boron oligomer, 10 parts of color paste, 10 parts of isopropyl alcohol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence by weight, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product.

[0032] Comparative Example 3: Allyl glycidyl ether was used to replace the silicon boron oligomer, and the rest was the same as Example 1; Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyethylene glycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; Step 1: Add 55 parts of polyurethane emulsion, 10 parts of allyl glycidyl ether, 10 parts of color paste, 10 parts of isopropanol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence by weight, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product.

[0033] Comparative Example 4: The amount of silicon boron oligomer introduced was increased, and the rest was the same as Example 1.

[0034] Pre-preparation: S1-1: By weight, 10 parts of titanium dioxide were added to 20 parts of acetone and dispersed evenly, 2.5 parts of isophorone diisocyanate were added, stirred for 1.5 hours, left for 5 hours, filtered, and heat-dried to obtain modified titanium dioxide; S1-2: 10 parts of polyethylene wax, 0.05 parts of tert-butyl peroxide, and 2 parts of 2-methyl-2-propene-1-ol were added to 30 parts of benzene in sequence, heated to 80° C., stirred and reacted for 2 hours, filtered, washed, and dried to obtain modified polyethylene wax; S1-3: According to weight, 82 parts of polytetramethylene ether glycol and 13 parts of tetrafluorobutanediol were vacuum dehydrated and then mixed evenly with 55 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate, and the mixture was heated to 75°C for reaction for 3 hours; an acetone mixed solution containing 2 parts of 1,4-butanediol, 5 parts of modified polyethylene wax and 3 parts of modified titanium dioxide was added, and the mixture was stirred and reacted for 1 hour; 25 parts of trimethylolpropane tris(3-mercaptopropionic acid) was added, and the mixture was stirred and reacted for 1 hour; acetone was evaporated; 0.6 parts of allyl polyethylene glycol ether JFB-23 and deionized water were added for emulsification to obtain a polyurethane emulsion with a solid content of 30wt%; S2: Boric acid, 3,5-difluorophenylboric acid, 3-glycidylpropyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7:0.3:0.8:1.2 are added to diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 155°C for 3 hours; the solvent and by-products are flash evaporated; and freeze-dried to obtain silicon boron oligomers.

[0035] Step 1: Add 55 parts of polyurethane emulsion, 15 parts of silicon boron oligomer, 10 parts of color paste, 10 parts of isopropyl alcohol, 0.02 parts of photoinitiator 500, and 0.5 parts of defoamer KSZ-108 to 10 parts of deionized water in sequence, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on it, and set the light intensity to 200mW / cm 2 , UV light exposure for 12 minutes, heat drying at 80°C to obtain the printed product.

[0036] Performance Test 1: The printed products prepared in the examples and comparative examples were subjected to relevant performance tests; 2The ink layer is used as the test sample; (1) Cover the ink layer with 3M tape, peel it off at 90° after sticking it firmly, and calculate the adhesion strength A based on the front and back area adhesion strength; (2) Place it in an environment with a temperature of 70℃ and a humidity of 98% for 3 days; Observe the surface of the ink layer and grade it from 0 to 5; Among them, grade 0 is the best performance, which means no smudge; grade 5 is the worst performance, which means very serious smudge; (3) Cover the surface of the ink layer with white paper, load a 2kg weight on its surface, rub it back and forth 100 times at 85r / min, and grade the surface color of the white paper from 0 to 5, among which grade 0 is the best performance, which means basically no color; grade 5 is the worst performance, which means dyeing exceeds 50%. The obtained data are shown in the following table:

[0037] Conclusion: From the data in the above table, it can be seen that the waterproof ink prepared in this application has excellent adhesion, water resistance and abrasion resistance. The invention uses a polyurethane emulsion containing specific segments and components as a linker, and assists with silicon boron oligomers to promote cross-linking, which effectively improves the printing properties and printing quality of the waterproof ink. At the same time, by optimizing the content of relevant components in the polyurethane emulsion and the content of silicon boron oligomers, the printing quality of the corrugated box surface is comprehensively improved, which promotes practical applicability.

[0038] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for printing waterproof ink on the surface of a corrugated paper box, characterized in that: The following steps are involved: Step 1: Add polyurethane emulsion, silicon boron oligomer, color paste, isopropyl alcohol, photoinitiator and defoamer into deionized water in sequence, stir and homogenize to obtain waterproof ink; Step 2: Remove dust from the surface of the corrugated box, print waterproof ink on the surface, irradiate with ultraviolet light and heat dry to obtain a printed product.

2. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 1, characterized in that: The raw materials of the waterproof ink include the following components: by weight, 52-58 parts of polyurethane emulsion, 8-12 parts of silicon boron oligomer, 8-12 parts of color paste, 8-10 parts of isopropyl alcohol, 0.01-0.02 parts of photoinitiator, 0.2-0.5 parts of defoamer, and 10-12 parts of deionized water.

3. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 1, characterized in that: The parameters of the ultraviolet light are: light intensity is 100-200mW / cm 2 , time is 8~15 minutes; the temperature of the hot drying is 60~80℃.

4. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 1, characterized in that: The preparation method of the polyurethane emulsion is: After vacuum dehydration, polytetramethylene ether glycol and tetrafluorobutanediol are mixed evenly with isophorone diisocyanate and dibutyltin dilaurate, and the temperature is raised to 70-80°C for reaction for 2-3 hours; an acetone mixed solution containing 1,4-butanediol, modified polyethylene wax and modified titanium dioxide is added, and the reaction is continued with stirring for 1-1.5 hours; trimethylolpropane tris(3-mercaptopropionic acid) is added, and the reaction is stirred for 1-2 hours; acetone is evaporated; allyl polyethylene glycol ether and deionized water are added for emulsification to obtain a polyurethane emulsion with a solid content of 30-35wt%.

5. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 4, characterized in that: The polyurethane emulsion comprises the following components: by weight, 80-85 parts of polytetramethylene ether glycol, 10-15 parts of tetrafluorobutanediol, 50-60 parts of isophorone diisocyanate, 0.2-0.5 parts of dibutyltin dilaurate, 2-3 parts of 1,4-butanediol, 4-6 parts of modified polyethylene wax, 3-5 parts of modified titanium dioxide, 20-25 parts of hydroxymethylpropane tris(3-mercaptopropionic acid) ester, and 0.5-1 part of allyl polyethylene glycol ether.

6. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 4, characterized in that: The preparation method of the modified titanium dioxide is as follows: adding titanium dioxide to an acetone solvent and dispersing the titanium dioxide uniformly, adding isophorone diisocyanate, stirring for 1 to 2 hours, leaving the mixture for 2 to 6 hours, filtering, and heat drying to obtain the modified titanium dioxide; wherein the mass ratio of titanium dioxide to isophorone diisocyanate is 1:0.2 to 0.

3.

7. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 4, characterized in that: The preparation method of the polyethylene wax emulsion is as follows: polyethylene wax, tert-butyl peroxide, and 2-methyl-2-propylene-1-ol are added to benzene in sequence, the temperature is raised to 80-85° C., the mixture is stirred and reacted for 2-3 hours, and the mixture is filtered, washed, and dried to obtain the modified polyethylene wax; wherein the mass ratio of the polyethylene wax, tert-butyl peroxide, and 2-methyl-2-propylene-1-ol is 10:0.05:1-3.

8. The process for printing waterproof ink on the surface of a corrugated paper box according to claim 1, characterized in that: The preparation method of the silicon boron oligomer is as follows: boric acid, 3,5-difluorophenylboric acid, 3-glycidyl propyl ether trimethoxysilane and vinyl trimethoxysilane in a molar ratio of 0.7-0.8:0.2-0.3:0.6-0.8:1.2-1.4 are added to a diethylene glycol dimethyl ether solvent in sequence, and stirred for reaction at 150-160° C. for 2-3 hours; the solvent and by-products are removed by flash evaporation; and freeze-drying is performed to obtain the silicon boron oligomer.

9. A printed product obtained by the surface waterproof ink printing process for a corrugated paper box according to any one of claims 1 to 8.

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