Water-resistant corrugated packaging material

Abstract

This invention relates to a water-resistant corrugated packaging material, belonging to the technical field of corrugated packaging materials. The invention first treats nano-sized silica with an amino silane coupling agent to modify it with amino groups, and then treats micron-sized silica with an epoxy silane coupling agent to modify it with epoxy groups. Through the interaction of amino and epoxy groups, nano-sized silica is composited onto the surface of the micron-sized silica, forming a micro / nano structure. Next, dopamine hydrochloride is used to self-polymerize and encapsulate it under aerobic and alkaline conditions, providing a secondary modification platform. Finally, a silaneoxy hydrophobic modifier is added, and through the interaction of silaneoxy and hydroxyl groups, the micro / nano structure acquires low surface energy, thus preparing a modified filler. When mixed with other components, the resulting coating, when applied to corrugated cardboard boxes, not only imparts superhydrophobic properties to the surface of the corrugated cardboard box but also exhibits excellent durability.

Description

Technical Field

[0001] This invention belongs to the technical field of corrugated packaging materials, specifically relating to a water-resistant corrugated packaging material. Background Technology

[0002] Corrugated cardboard boxes are a very common corrugated packaging material. They are made from corrugated cardboard through die-cutting, creasing, stapling, or gluing. In daily life, corrugated cardboard boxes are widely used for packaging goods due to their portability and low cost. However, because the raw materials for making corrugated cardboard boxes / corrugated cardboard are mainly chemical components such as cellulose and hemicellulose, their water resistance is very poor. The large number of hydrophilic hydroxyl groups on the surface makes them extremely susceptible to moisture absorption, seriously affecting their normal packaging function. To solve this technical problem, many existing technologies use lamination to give corrugated cardboard boxes a better water resistance. It has water resistance and moisture resistance. For example, by introducing hydrophobic functional fillers into the film-forming material, a hydrophobic surface can be formed well, thereby improving water resistance. However, this technology still has drawbacks that limit its practical application. This is because, on the one hand, the water resistance after coating is still limited and does not reach the superhydrophobic property. On the other hand, even if the superhydrophobic property is achieved, the surface of corrugated cardboard boxes will experience a lot of friction and wear during actual use. At this time, the micro-nano rough structure formed by the hydrophobic functional filler is easily damaged, which affects the durability and makes it impossible to achieve a long-lasting superhydrophobic effect. Summary of the Invention

[0003] To address the problems existing in the prior art, the purpose of this invention is to provide a water-resistant corrugated packaging material. This invention first treats nano-sized silica with an amino silane coupling agent to modify it with amino groups, and then treats micron-sized silica with an epoxy silane coupling agent to modify it with epoxy groups. Through the interaction of amino and epoxy groups, nano-sized silica is composited onto the surface of the micron-sized silica, forming a micro / nano structure. Next, dopamine hydrochloride is used to self-polymerize and encapsulate it under aerobic and alkaline conditions, providing a secondary modification platform. Finally, a silaneoxy hydrophobic modifier is added, and through the interaction of silaneoxy and hydroxyl groups, the micro / nano structure acquires low surface energy, thereby preparing a modified filler. When mixed with other components, the resulting coating, when applied to the coating of corrugated boxes, not only imparts superhydrophobic properties to the surface of the corrugated box but also exhibits excellent durability.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for preparing a water-resistant corrugated packaging material, the method comprising the following steps:

[0006] (1) Apply coating to the surface of the corrugated cardboard box, dry it to form a coating, and the preparation is complete.

[0007] As a preferred technical solution of the present invention, the coating in step (1) is prepared from 75-80 parts by weight of epoxy resin, 18-20 parts by weight of curing agent, 4-5 parts by weight of modified filler and 0.5-1 parts by weight of film-forming aid.

[0008] Furthermore, the epoxy resin is obtained by purchasing it directly from the market.

[0009] Furthermore, the curing agent is at least one of diethylenetriamine and triethylenetetramine.

[0010] Furthermore, the modified filler is prepared through the following steps:

[0011] Step a: Add 5-7 parts by weight of nano-sized silica, 0.5-1 parts by weight of deionized water and 0.3-0.5 parts by weight of aminosilane coupling agent to 80-100 parts by weight of anhydrous ethanol, stir at 65-70℃ for 23-25 ​​hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60℃ until constant weight to obtain aminated nano-sized silica;

[0012] Step b: Add 5-7 parts by weight of micron-sized silica, 0.5-1 parts by weight of deionized water and 0.3-0.5 parts by weight of epoxy silane coupling agent to 80-100 parts by weight of anhydrous ethanol, stir at 65-70°C for 23-25 ​​hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60°C until constant weight to obtain epoxy-oxidized micron-sized silica.

[0013] Step c: Add 5-7 parts by weight of aminated nano-sized silica to 80-100 parts by weight of anhydrous ethanol, and stir at room temperature for 5-10 minutes to obtain dispersion a; add 10-12 parts by weight of epoxy-modified micron-sized silica to 140-150 parts by weight of anhydrous ethanol, and stir at room temperature for 5-10 minutes to obtain dispersion b; add dispersion a dropwise to dispersion b while stirring at 30-40℃, and continue stirring at a constant temperature for 2-3 hours after the addition is complete, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60℃ until constant weight to obtain composite micro-nano-sized silica;

[0014] Step d: Add 3-5 parts by weight of composite micro / nano-sized silica and 5-6 parts by weight of dopamine hydrochloride to 100-120 parts by weight of Tris-HCl buffer solution, stir at 25-30°C for 12-14 hours in contact with air, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50-60°C until constant weight to obtain organically coated micro / nano-sized silica.

[0015] Step e: Add 5-7 parts by weight of organic-coated micro / nano-sized silica to 80-100 parts by weight of deionized water, stir at room temperature for 5-10 minutes to mix, then add 0.5-1 parts by weight of silaneoxy hydrophobic modifier dropwise while stirring at 70-80℃. After the addition is complete, continue stirring at a constant temperature for 10-12 hours, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50-60℃ until constant weight is achieved, thus completing the preparation.

[0016] Preferably, the particle size of the nano-sized silica in step a is 10-30 nm.

[0017] Preferably, the aminosilane coupling agent in step a is at least one of γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0018] Preferably, the particle size of the micron-sized silica in step b is 0.15-0.2 μm.

[0019] Preferably, the epoxy silane coupling agent in step b is at least one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane.

[0020] Preferably, the dripping rate in step c is controlled at 1-3 drops / s.

[0021] Preferably, the pH of the Tris-HCl buffer solution in step d is 8-8.5.

[0022] Preferably, the dripping rate in step e is controlled at 1 drop / s.

[0023] Preferably, the silaneoxy hydrophobic modifier in step e is at least one of dodecyltrimethoxysilane, dodecyltriethoxysilane, and hexadecyltrimethoxysilane.

[0024] Furthermore, the film-forming aid is a dodecyl alcohol ester.

[0025] As a preferred technical solution of the present invention, the coating in step (1) is prepared by the following steps:

[0026] Step X: Add curing agent, modified filler and film-forming aid to epoxy resin, then stir at 1500-2000 r / min at room temperature for 5-10 min to mix, and finally degas under vacuum for 5 min to complete the preparation.

[0027] As a preferred technical solution of the present invention, the drying in step (1) refers to drying at 50°C for 7-8 hours.

[0028] As a preferred technical solution of the present invention, the coating formation in step (1) refers to forming a coating with a thickness of 0.1-0.2 mm.

[0029] A water-resistant corrugated packaging material prepared by the method described above.

[0030] The beneficial effects of this invention are:

[0031] (1) In this invention, nano-sized silica is first treated with an amino silane coupling agent to modify it with amino groups, and micro-sized silica is treated with an epoxy silane coupling agent to modify it with epoxy groups. Then, through the action of amino and epoxy groups, nano-sized silica is composited on the surface of micro-sized silica to form a micro-nano structure. Next, dopamine hydrochloride is used to self-polymerize and encapsulate it under aerobic and alkaline conditions to provide a secondary modification platform. Finally, a silaneoxy hydrophobic modifier is added. Through the action of silaneoxy and hydroxyl groups, the micro-nano structure has low surface energy, thereby preparing a modified filler. When the coating obtained by mixing it with other components is applied to the coating of corrugated boxes, it not only endows the surface of the corrugated boxes with superhydrophobic properties, but also has excellent durability.

[0032] (2) This invention creatively combines nano-sized and micro-sized silica through chemical bonds to construct a very stable micro-nano structure. Then, dopamine hydrochloride is used to self-polymerize and encapsulate the micro-nano structure under aerobic and alkaline conditions. After encapsulation, a secondary modification platform can be provided. Polydopamine is a substance containing a large number of hydroxyl and amino groups. Its hydroxyl groups can react with the silane groups of the silane group hydrophobic modifier, thereby giving the micro-nano structure a low surface energy. Its amino groups can participate in the curing in the epoxy resin-amine system, thereby bonding the micro-nano structure to the epoxy resin in the form of chemical bonds. In actual use, it can effectively reduce the wear and damage of the micro-nano structure caused by external forces. On the other hand, it also transforms from organic phase to inorganic phase to organic phase to organic phase. The epoxy resin and the modified filler have good compatibility and strong dispersibility, which can better exert the wear resistance of silica itself, further reduce the wear and damage that may occur to the micro-nano structure, and thus ensure the durability and long-term effectiveness of the superhydrophobic properties.

[0033] (3) The corrugated packaging material provided by the present invention has superhydrophobic properties on its surface, excellent water resistance, and strong practicality. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0035] All corrugated cartons used in the embodiments and comparative examples of this invention are from Zhengye Packaging (Zhongshan) Co., Ltd., and are made of E-type corrugated cardboard with a basis weight of 445 g / m³. 2 The epoxy resins were all purchased directly from the market; the manufacturer was Henson Chemicals in the United States, and the model was Epikote 6520-WH-53A.

[0036] Example 1

[0037] A method for preparing a water-resistant corrugated packaging material, the method comprising the following steps:

[0038] (1) Apply coating to the surface of the corrugated cardboard box, dry it to form a coating, and the preparation is complete.

[0039] The coating in step (1) is prepared from 75 parts by weight of epoxy resin, 18 parts by weight of curing agent, 4 parts by weight of modified filler and 0.5 parts by weight of film-forming aid.

[0040] The epoxy resin was obtained by purchasing it directly from the market.

[0041] The curing agent is diethylenetriamine.

[0042] The modified filler is prepared by the following steps:

[0043] Step a: Add 5 parts by weight of nano-sized silica, 0.5 parts by weight of deionized water and 0.3 parts by weight of aminosilane coupling agent to 80 parts by weight of anhydrous ethanol, stir at 65°C for 23 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50°C until constant weight to obtain aminated nano-sized silica.

[0044] Step b: Add 5 parts by weight of micron-sized silica, 0.5 parts by weight of deionized water and 0.3 parts by weight of epoxy silane coupling agent to 80 parts by weight of anhydrous ethanol, stir at 65°C for 23 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50°C until constant weight to obtain epoxy-oxidized micron-sized silica.

[0045] Step c: Add 5 parts by weight of aminated nano-sized silica to 80 parts by weight of anhydrous ethanol and stir at room temperature for 5 min to obtain dispersion a; add 10 parts by weight of epoxy-modified micron-sized silica to 140 parts by weight of anhydrous ethanol and stir at room temperature for 5 min to obtain dispersion b; add dispersion a dropwise to dispersion b while stirring at 30°C, and continue stirring at a constant temperature for 2 h after the addition is complete, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50°C until constant weight to obtain composite micro-nano-sized silica;

[0046] Step d: Add 3 parts by weight of composite micro / nano-sized silica and 5 parts by weight of dopamine hydrochloride to 100 parts by weight of Tris-HCl buffer solution, stir at 25°C for 12 hours in contact with air, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50°C until constant weight to obtain organic-coated micro / nano-sized silica.

[0047] Step e: Add 5 parts by weight of organic-coated micro / nano-sized silica to 80 parts by weight of deionized water, stir at room temperature for 5 minutes to mix, then add 0.5 parts by weight of silaneoxy hydrophobic modifier dropwise while stirring at 70°C. After the addition is complete, continue stirring at a constant temperature for 10 hours, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50°C until constant weight, thus completing the preparation.

[0048] The nanoscale silica in step a has a particle size of 10 nm.

[0049] The aminosilane coupling agent mentioned in step a is γ-aminopropyltrimethoxysilane.

[0050] The particle size of the micron-sized silica mentioned in step b is 0.15 μm.

[0051] The epoxy silane coupling agent mentioned in step b is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0052] The dripping rate in step c is controlled at 1 drop / s.

[0053] The pH of the Tris-HCl buffer solution described in step d is 8.

[0054] The dropping rate in step e is controlled at 1 drop / s.

[0055] The silaneoxy hydrophobic modifier mentioned in step e is dodecyltrimethoxysilane.

[0056] The film-forming aid is a dodecyl alcohol ester.

[0057] The coating described in step (1) is prepared through the following steps:

[0058] Step X: Add curing agent, modified filler and film-forming aid to epoxy resin, then stir for 5 minutes at 1500 r / min at room temperature, and finally degas under vacuum for 5 minutes to complete the preparation.

[0059] The drying process described in step (1) refers to drying at 50°C for 7 hours.

[0060] The coating formation mentioned in step (1) refers to the formation of a coating with a thickness of 0.1 mm.

[0061] A water-resistant corrugated packaging material prepared by the method described above.

[0062] Example 2

[0063] A method for preparing a water-resistant corrugated packaging material, the method comprising the following steps:

[0064] (1) Apply coating to the surface of the corrugated cardboard box, dry it to form a coating, and the preparation is complete.

[0065] The coating in step (1) is prepared from 80 parts by weight of epoxy resin, 20 parts by weight of curing agent, 5 parts by weight of modified filler and 1 part by weight of film-forming aid.

[0066] The epoxy resin was obtained by purchasing it directly from the market.

[0067] The curing agent is diethylenetriamine.

[0068] The modified filler is prepared by the following steps:

[0069] Step a: Add 7 parts by weight of nano-sized silica, 1 part by weight of deionized water and 0.5 parts by weight of aminosilane coupling agent to 100 parts by weight of anhydrous ethanol, stir at 70°C for 25 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 60°C until constant weight to obtain amino-modified nano-sized silica.

[0070] Step b: Add 7 parts by weight of micron-sized silica, 1 part by weight of deionized water and 0.5 parts by weight of epoxy silane coupling agent to 100 parts by weight of anhydrous ethanol, stir at 70°C for 25 h, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 60°C until constant weight to obtain epoxy-oxidized micron-sized silica.

[0071] Step c: Add 7 parts by weight of aminated nano-sized silica to 100 parts by weight of anhydrous ethanol and stir at room temperature for 10 min to obtain dispersion a; add 12 parts by weight of epoxy-modified micron-sized silica to 150 parts by weight of anhydrous ethanol and stir at room temperature for 10 min to obtain dispersion b; add dispersion a dropwise to dispersion b while stirring at 40°C, and continue stirring at a constant temperature for 3 h after the addition is complete, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 60°C until constant weight to obtain composite micro-nano-sized silica;

[0072] Step d: Add 5 parts by weight of composite micro / nano-sized silica and 6 parts by weight of dopamine hydrochloride to 120 parts by weight of Tris-HCl buffer solution, stir at 30°C for 14 hours in contact with air, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 60°C until constant weight to obtain organically coated micro / nano-sized silica.

[0073] Step e: Add 7 parts by weight of organic-coated micro / nano-sized silica to 100 parts by weight of deionized water, stir at room temperature for 10 min to mix, then add 1 part by weight of silaneoxy hydrophobic modifier dropwise while stirring at 80°C. After the addition is complete, continue stirring at a constant temperature for 12 h, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 60°C until constant weight, thus completing the preparation.

[0074] The particle size of the nano-sized silica mentioned in step a is 30 nm.

[0075] The aminosilane coupling agent mentioned in step a is γ-aminopropyltrimethoxysilane.

[0076] The micron-sized silica in step b has a particle size of 0.2 μm.

[0077] The epoxy silane coupling agent mentioned in step b is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0078] The dripping rate in step c is controlled at 3 drops / s.

[0079] The pH of the Tris-HCl buffer solution described in step d is 8.5.

[0080] The dropping rate in step e is controlled at 1 drop / s.

[0081] The silaneoxy hydrophobic modifier mentioned in step e is dodecyltrimethoxysilane.

[0082] The film-forming aid is a dodecyl alcohol ester.

[0083] The coating described in step (1) is prepared through the following steps:

[0084] Step X: Add curing agent, modified filler and film-forming aid to epoxy resin, then stir for 10 minutes at 2000 r / min at room temperature, and finally degas under vacuum for 5 minutes to complete the preparation.

[0085] The drying process described in step (1) refers to drying at 50°C for 8 hours.

[0086] The coating formation mentioned in step (1) refers to the formation of a coating with a thickness of 0.2 mm.

[0087] A water-resistant corrugated packaging material prepared by the method described above.

[0088] Example 3

[0089] A method for preparing a water-resistant corrugated packaging material, the method comprising the following steps:

[0090] (1) Apply coating to the surface of the corrugated cardboard box, dry it to form a coating, and the preparation is complete.

[0091] The coating in step (1) is prepared from 78 parts by weight of epoxy resin, 19 parts by weight of curing agent, 4.5 parts by weight of modified filler and 0.8 parts by weight of film-forming aid.

[0092] The epoxy resin was obtained by purchasing it directly from the market.

[0093] The curing agent is diethylenetriamine.

[0094] The modified filler is prepared by the following steps:

[0095] Step a: Add 6 parts by weight of nano-sized silica, 0.8 parts by weight of deionized water and 0.4 parts by weight of aminosilane coupling agent to 90 parts by weight of anhydrous ethanol, stir at 68°C for 24 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 55°C until constant weight to obtain aminated nano-sized silica.

[0096] Step b: Add 6 parts by weight of micron-sized silica, 0.8 parts by weight of deionized water and 0.4 parts by weight of epoxy silane coupling agent to 90 parts by weight of anhydrous ethanol, stir at 68°C for 24 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 55°C until constant weight to obtain epoxy-oxidized micron-sized silica.

[0097] Step c: Add 6 parts by weight of aminated nano-sized silica to 90 parts by weight of anhydrous ethanol and stir at room temperature for 8 minutes to obtain dispersion a; add 11 parts by weight of epoxy-modified micron-sized silica to 145 parts by weight of anhydrous ethanol and stir at room temperature for 8 minutes to obtain dispersion b; add dispersion a dropwise to dispersion b while stirring at 35°C, and continue stirring at a constant temperature for 2.5 hours after the addition is complete, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 55°C until constant weight to obtain composite micro-nano-sized silica;

[0098] Step d: Add 4 parts by weight of composite micro / nano-sized silica and 5.5 parts by weight of dopamine hydrochloride to 110 parts by weight of Tris-HCl buffer solution, stir at 28°C for 13 hours in contact with air, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 55°C until constant weight to obtain organically coated micro / nano-sized silica.

[0099] Step e: Add 6 parts by weight of organic-coated micro / nano-sized silica to 90 parts by weight of deionized water, stir at room temperature for 8 minutes to mix, then add 0.8 parts by weight of silaneoxy hydrophobic modifier dropwise while stirring at 75°C. After the addition is complete, continue stirring at a constant temperature for 11 hours, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 55°C until constant weight, thus completing the preparation.

[0100] The particle size of the nanoscale silica mentioned in step a is 20 nm.

[0101] The aminosilane coupling agent mentioned in step a is γ-aminopropyltrimethoxysilane.

[0102] The particle size of the micron-sized silica mentioned in step b is 0.18 μm.

[0103] The epoxy silane coupling agent mentioned in step b is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0104] The dripping rate in step c is controlled at 2 drops / s.

[0105] The pH of the Tris-HCl buffer solution described in step d is 8.3.

[0106] The dropping rate in step e is controlled at 1 drop / s.

[0107] The silaneoxy hydrophobic modifier mentioned in step e is dodecyltrimethoxysilane.

[0108] The film-forming aid is a dodecyl alcohol ester.

[0109] The coating described in step (1) is prepared through the following steps:

[0110] Step X: Add curing agent, modified filler and film-forming aid to epoxy resin, then stir for 8 minutes at 1800 r / min at room temperature, and finally degas under vacuum for 5 minutes to complete the preparation.

[0111] The drying process described in step (1) refers to drying at 50°C for 7.5 hours.

[0112] The coating formation mentioned in step (1) refers to the formation of a coating with a thickness of 0.15 mm.

[0113] A water-resistant corrugated packaging material prepared by the method described above.

[0114] Comparative Example 1

[0115] Based on Example 1, the aminosilane coupling agent in step a was replaced with an equal weight of deionized water, and the epoxysilane coupling agent in step b was replaced with an equal weight of deionized water, with all other steps remaining unchanged.

[0116] Comparative Example 2

[0117] Based on Example 1, in step e, the silaneoxy hydrophobic modifier was replaced with an equal weight of deionized water, while all other steps remained unchanged.

[0118] Comparative Example 3

[0119] Based on Example 1, step e is omitted, and step d is changed to adding 5 parts by weight of composite micro / nano-sized silica, 0.5 parts by weight of deionized water, 0.3 parts by weight of dodecyltrimethoxysilane, and 0.3 parts by weight of γ-aminopropyltrimethoxysilane to 100 parts by weight of anhydrous ethanol. Then, the mixture is stirred at 70°C for 23 hours, filtered, the filtrate is removed, washed with anhydrous ethanol, and finally vacuum dried at 50°C until constant weight is achieved, thus completing the preparation. All other steps remain unchanged.

[0120] Comparative Example 4

[0121] Based on Example 1, step e is changed to adding 5 parts by weight of organically coated micro / nano-sized silica to 80 parts by weight of deionized water, stirring at room temperature for 5 minutes to mix, and then adding 0.5 parts by weight of silaneoxy hydrophobic modifier dropwise while stirring at 70°C. After the addition is complete, continue stirring at a constant temperature for 10 hours, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50°C until constant weight to obtain the material; add 100 parts by weight of anhydrous ethanol and 5 parts by weight of 1,2-epoxyhexane to the material, stir at 40°C for 12 hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50°C until constant weight to complete the preparation; all other steps remain unchanged.

[0122] Test Example 1

[0123] Water resistance test:

[0124] The static contact angle and rolling contact angle of the water-resistant corrugated packaging materials prepared in Examples 1-3 and Comparative Examples 1-4 were tested respectively.

[0125] Table 1. Water resistance test results

[0126] Static contact angle / degree Rolling contact angle / degrees Example 1 157.4 7.3 Example 2 159.6 6.8 Example 3 159.5 7.0 Comparative Example 1 141.8 23.5 Comparative Example 2 105.2 64.9 Comparative Example 3 157.0 7.2 Comparative Example 4 157.9 7.2

[0127] Test Example 2

[0128] Durability testing:

[0129] Place 600-grit sandpaper on the surface of the water-resistant corrugated packaging materials prepared in Examples 1-3 and Comparative Examples 1-4, respectively. Then drag the sandpaper 10 times under the pressure of a 400g weight, with each drag distance being 20cm. Finally, retest the static contact angle and rolling contact angle after dragging.

[0130] Table 2. Durability Test Results

[0131]

[0132]

[0133] A comparison of Example 1 and Comparative Examples 1-4 shows that:

[0134] The difference between Comparative Example 1 and Example 1 is that nanoscale silica was not composited on the surface of micron-scale silica.

[0135] The difference between Comparative Example 2 and Example 1 is that no silaneoxy hydrophobic modifier was added to form a low surface energy for the micro / nano structure.

[0136] The difference between Comparative Example 3 and Example 1 is that the micro / nano structure was not self-polymerized and encapsulated with dopamine hydrochloride; however, it was still modified with amino groups and formed a low surface energy.

[0137] The difference between Comparative Example 4 and Example 1 is that 1,2-epoxyhexane was added to consume the surface amino groups of the modified filler.

[0138] As can be seen from Test Example 1, Example 1 and Comparative Examples 1-4, the water-resistant corrugated packaging material prepared by the present invention has superhydrophobic properties and excellent water resistance.

[0139] As can be seen from the comparison between Example 1 and Comparative Examples 1-4 in Test Example 2, the water-resistant corrugated packaging material prepared by the present invention has excellent superhydrophobic durability. Even after friction and wear, its static contact angle still decreases very little and still exhibits superhydrophobic properties.

[0140] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for producing a water-resistant corrugated packaging material, characterized by: The preparation method includes the following steps: (1) Apply coating to the surface of the corrugated cardboard box, dry it to form a coating, and the preparation is complete; The coating described in step (1) is prepared from 75-80 parts by weight of epoxy resin, 18-20 parts by weight of curing agent, 4-5 parts by weight of modified filler and 0.5-1 parts by weight of film-forming aid. The modified filler is prepared through the following steps: Step a: Add 5-7 parts by weight of nano-sized silica, 0.5-1 parts by weight of deionized water and 0.3-0.5 parts by weight of aminosilane coupling agent to 80-100 parts by weight of anhydrous ethanol, stir at 65-70℃ for 23-25 ​​hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60℃ until constant weight to obtain aminated nano-sized silica; Step b: Add 5-7 parts by weight of micron-sized silica, 0.5-1 parts by weight of deionized water and 0.3-0.5 parts by weight of epoxy silane coupling agent to 80-100 parts by weight of anhydrous ethanol, stir at 65-70°C for 23-25 ​​hours, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60°C until constant weight to obtain epoxy-oxidized micron-sized silica. Step c: Add 5-7 parts by weight of aminated nano-sized silica to 80-100 parts by weight of anhydrous ethanol, and stir at room temperature for 5-10 minutes to obtain dispersion a; add 10-12 parts by weight of epoxy-modified micron-sized silica to 140-150 parts by weight of anhydrous ethanol, and stir at room temperature for 5-10 minutes to obtain dispersion b; add dispersion a dropwise to dispersion b while stirring at 30-40℃, and continue stirring at a constant temperature for 2-3 hours after the addition is complete, filter, remove the filtrate, wash with anhydrous ethanol, and finally vacuum dry at 50-60℃ until constant weight to obtain composite micro-nano-sized silica; Step d: Add 3-5 parts by weight of composite micro / nano-sized silica and 5-6 parts by weight of dopamine hydrochloride to 100-120 parts by weight of Tris-HCl buffer solution, stir at 25-30°C for 12-14 hours in contact with air, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50-60°C until constant weight to obtain organically coated micro / nano-sized silica. Step e: Add 5-7 parts by weight of organic-coated micro / nano-sized silica to 80-100 parts by weight of deionized water, stir at room temperature for 5-10 minutes to mix, then add 0.5-1 parts by weight of silaneoxy hydrophobic modifier dropwise while stirring at 70-80℃. After the addition is complete, continue stirring at a constant temperature for 10-12 hours, filter, remove the filtrate, wash with deionized water, and finally vacuum dry at 50-60℃ until constant weight is achieved, thus completing the preparation.

2. A method of making a water-resistant corrugated packaging material according to claim 1, characterized in that: The curing agent is at least one of diethylenetriamine and triethylenetetramine.

3. A process for the production of a water resistant corrugated packaging material according to claim 1, characterized in that: The aminosilane coupling agent in step a is at least one of γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

4. A method of making a water resistant corrugated packaging material according to claim 1, characterized in that: The epoxy silane coupling agent in step b is at least one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane.

5. A method of making a water resistant corrugated packaging material according to claim 1, characterized in that: The silaneoxy hydrophobic modifier in step e is at least one of dodecyltrimethoxysilane, dodecyltriethoxysilane, and hexadecyltrimethoxysilane.

6. A method of making a water resistant corrugated packaging material according to claim 1, characterized in that: The drying process described in step (1) refers to drying at 50°C for 7-8 hours.

7. A method of making a water resistant corrugated packaging material according to claim 1, characterized in that: The coating formation mentioned in step (1) refers to the formation of a coating with a thickness of 0.1-0.2 mm.

8. A water-resistant corrugated packaging material prepared by the preparation method according to any one of claims 1-7.

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