A Blending Wax Composition for Coating Packaging Boxes and Its Preparation Method

Abstract

The present invention provides a blended wax composition for packaging box coating and a preparation method thereof, belonging to the technical field of packaging materials. The preparation raw materials include the following components by weight: 50-70 parts of paraffin wax, 10-15 parts of microcrystalline wax, 5-10 parts of natural bio-based wax, 2-4 parts of cold-resistant plasticizer, 10-20 parts of modified furan polyester, 5-10 parts of modified nanoparticles, 0.5-1 part of antioxidant, 1-3 parts of emulsifier, 70-80 parts of water, and 3-5 parts of catalyst. The blended wax composition for packaging box coating of the present invention has good waterproof, oxygen barrier, adhesion and easy dyeing properties, good high and low temperature resistance, certain roughness after curing, good freshness preservation effect, can extend the shelf life, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, and particularly relates to a blending wax composition for box coating and a preparation method thereof. Background Art

[0002] With the rapid development of the logistics industry, paper packaging containers play an increasingly important role. Among them, corrugated cardboard boxes are the most commonly used paper packaging containers in people's production and life. It can keep fresh and waterproof when used for packaging fruits, vegetables, and seafood products, reduce internal wear when used for packaging furniture and wood products, and also meet the requirement that rubber products cannot adhere to the cardboard box during transportation. However, problems such as the reduction of cardboard box strength, damage and deformation caused by moisture have always attracted people's attention because they directly affect the use effect and appearance of the cardboard box. Therefore, the waterproof and moisture-proof process is an issue that cardboard box producers must consider.

[0003] The waterproof and moisture-proof process of cardboard boxes is divided into external and internal waterproof and moisture-proof processes. The external waterproof and moisture-proof process refers to moisture-proofing the surface of the cardboard box, and the internal waterproof and moisture-proof process refers to moisture-proofing the pulp used to make the cardboard box. The surface treatment of cardboard mainly includes three treatment methods: coating, impregnation, and lamination. Wax coating is a method of applying a waterproof and moisture-proof material in the coating treatment.

[0004] The national invention patent application CN112030599A previously applied by the company discloses a blending wax for aquatic product box coating and a preparation method thereof. The blending wax for aquatic product box coating includes the following raw materials in parts by weight: 55 - 75 parts of paraffin wax, 10 - 15 parts of microcrystalline wax, 5 - 10 parts of polyethylene wax, 10 - 15 parts of poly-α-olefin, 2 - 5 parts of hydrogenated C5 petroleum resin, and 0.8 - 1.2 parts of antioxidant. Each component acts synergistically. After being coated on the aquatic product box, the aquatic product box can simultaneously have excellent waterproof performance, tear resistance, adhesion, and toughness. However, this composition does not have good oxygen barrier, low-temperature resistance, freshness preservation, and easy dyeing characteristics, thus limiting its application. Summary of the Invention

[0005] The purpose of the present invention is to provide a blending wax composition for box coating and a preparation method thereof, which has good waterproof, oxygen barrier, adhesion, and easy dyeing properties, good high and low temperature resistance, certain roughness after curing, good freshness preservation effect, can extend the shelf life, and has broad application prospects.

[0006] The technical solution of the present invention is realized as follows:

[0007] The present invention provides a blended wax composition for packaging box coating. The raw materials for preparation include the following components by weight: 50-70 parts of paraffin wax, 10-15 parts of microcrystalline wax, 5-10 parts of natural bio-based wax, 2-4 parts of cold-resistant plasticizer, 10-20 parts of modified furan polyester, 5-10 parts of modified nanoparticles, 0.5-1 part of antioxidant, 1-3 parts of emulsifier, 70-80 parts of water, and 3-5 parts of catalyst; the modified furan polyester is poly(2,5-furandicarboxylic acid-ethylene glycol) ester modified by a silane coupling agent, and the modified nanoparticles are obtained by adding graphene-coated TiO2 / ZnO nanocomposites to molten paraffin wax, emulsifying to form sea urchin-shaped composite spheres, mixing with an emulsifier and carbon nanotubes, and spray drying.

[0008] As a further improvement of the present invention, the cold-resistant plasticizer is dioctyl adipate, and the catalyst is sodium chloride or potassium chloride; the paraffin wax is composed of No. 56 paraffin wax and No. 64 paraffin wax, and the mass ratio is 40-50:15-25; the natural bio-based wax is selected from at least one of carnauba wax and candelilla wax; the antioxidant is antioxidant 1010.

[0009] As a further improvement of the present invention, the preparation method of the modified furan polyester is as follows:

[0010] Add poly(2,5-furandicarboxylic acid-ethylene glycol) ester to 1,1,2,2-tetrachloroethane, heat to dissolve, cool, add a long-chain alkyl silane coupling agent, heat and stir to react, add the product to ethanol, filter, wash, and dry to obtain the modified furan polyester.

[0011] As a further improvement of the present invention, the mass ratio of poly(2,5-furandicarboxylic acid-ethylene glycol) ester to the long-chain alkyl silane coupling agent is 10:2-3, the long-chain alkyl silane coupling agent is selected from at least one of n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, n-dodecyltrimethoxysilane, and n-octadecyltrimethoxysilane, the temperature for heating and dissolving is 120-130 °C, and the temperature for heating and stirring to react is 40-50 °C, and the time is 3-5 h.

[0012] As a further improvement of the present invention, the preparation method of the modified nanoparticles is as follows:

[0013] S1. Preparation of modified TiO2 / ZnO nanocomposites: Dissolve tetrabutyl titanate and zinc acetate in ethanol, add water, add citric acid and concentrated hydrochloric acid, heat and stir to react, centrifuge, wash, dry, calcine, add the product to the graphene oxide aqueous dispersion, spray dry, and reduce with hydrazine vapor to obtain the modified TiO2 / ZnO nanocomposites;

[0014] S2. Preparation of sea urchin-shaped composite spheres: Add long-chain alkylsilane to an organic solvent to obtain an oil phase; add a pore-forming agent and an emulsifier to water to obtain an aqueous phase; add molten paraffin and a modified TiO2 / ZnO nanocomposite to the aqueous phase, and perform the first emulsification to form an emulsion suspension. Drop the emulsion suspension into the oil phase, adjust the pH value of the solution, perform the second emulsification, and freeze-dry to obtain sea urchin-shaped composite spheres;

[0015] S3. Preparation of modified nanoparticles: Add an emulsifier to water, add carbon nanotubes and sea urchin-shaped composite spheres, and spray-dry to obtain modified nanoparticles.

[0016] As a further improvement of the present invention, in step S1, the mass ratio of tetrabutyl titanate, zinc acetate, citric acid, concentrated hydrochloric acid, and graphene oxide aqueous dispersion is 8-12:4-6:7-10:3-5:5-10, the concentration of the graphene oxide aqueous dispersion is 0.1-0.2 mg / mL, the calcination temperature is 500-600 °C, the time is 1-3 h, the temperature of the heating and stirring reaction is 50-70 °C, the time is 4-6 h, and the reduction time is 5-7 h.

[0017] As a further improvement of the present invention, in step S2, the long-chain alkylsilane is selected from at least one of n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, n-dodecyltrimethoxysilane, and n-octadecyltrimethoxysilane, the pore-forming agent is selected from at least one of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, and cetylmethyldibenzylammonium chloride, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, Span-20, Span-40, Span-60, and Span-80, the mass ratio of the long-chain alkylsilane, pore-forming agent, emulsifier, paraffin, and modified TiO2 / ZnO nanocomposite is 10-15:2-3:1-2:4-7:2-3, the rotation speed of the first emulsification is 6000-8000 r / min, the time is 15-25 min, the pH value of the adjusted solution is 10-11, the rotation speed of the second emulsification is 8000-10000 r / min, and the time is 10-20 min.

[0018] As a further improvement of the present invention, in step S3, the emulsifier is selected from at least one of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and sodium dodecyl sulfonate, and the mass ratio of the emulsifier, carbon nanotubes, and sea urchin-shaped composite spheres is 1-2:4-6:12-15.

[0019] The present invention further protects a preparation method of the above-mentioned conditioning wax composition for packaging box coating, including the following steps:

[0020] Heat and mix paraffin wax, microcrystalline wax, natural biobased wax, modified furan polyester, cold-resistant plasticizer, and antioxidant evenly to obtain Phase A;

[0021] Add emulsifier and catalyst to water, stir and mix evenly to obtain Phase B;

[0022] (3) Add Phase B to Phase A, add modified nanoparticles, heat and emulsify to prepare the blended wax composition for coating the packaging box.

[0023] As a further improvement of the present invention, the temperature of the heat mixing in step (1) is 120 - 140 °C, the temperature of the heat emulsification in step (3) is 70 - 90 °C, the rotation speed of the emulsification is 8000 - 10000 r / min, and the time is 10 - 20 min.

[0024] The present invention has the following beneficial effects:

[0025] The present invention uses natural biobased wax to partially replace traditional petroleum-based waxes, such as carnauba wax, candelilla wax, etc. These biobased waxes are renewable, have a sustainable source, and have good gloss and hardness. The wax film made has a high gloss, can improve the appearance quality of the product, and at the same time conforms to the environmental protection concept and meets the market demand for green packaging.

[0026] The present invention adds a biodegradable biobased material, furan polyester, and modifies it with a long-chain alkyl silane coupling agent, making the prepared modified furan polyester have good dispersibility and compatibility in alkane paraffin-based materials. There is an oxygen atom in the monomer structure of furan polyester, so that after the blended wax composition is coated on the surface of the paper box, it can be affinity with oxygen. At the same time, it has a relatively large polarity, so it has good oxygen barrier and easy dyeing properties. The oxygen barrier thus improves the preservation period of the packaged contents. At the same time, it also has a good water barrier effect and improves the waterproof effect.

[0027] The present invention adds a modified nanoparticle. First, a TiO2 / ZnO nanocomposite is prepared by a sol-gel reaction, and graphene is covered on the surface by spray drying. After graphene is combined with titanium dioxide, the electron clouds of the two interact with each other. The π electron cloud of graphene couples with the conduction band and valence band electrons of titanium dioxide, changing the electronic structure of titanium dioxide. Graphene has good electrical conductivity, making the density distribution of the electronic states of titanium dioxide change, introducing some intermediate energy levels in its forbidden band. These intermediate energy levels reduce the energy required for electron transition. When combined with titanium dioxide, the photo-generated electrons can quickly transfer from the conduction band of titanium dioxide to graphene, and can also effectively inhibit the recombination of electron-hole pairs, so that the composite material can absorb part of the visible light and expand the light response range.

[0028] Then, by adding molten paraffin wax and modified TiO2 / ZnO nanocomposites into water, an oil-in-water emulsion suspension was formed through emulsification. Then, it was dropped into the oil phase and emulsified to form an oil-in-water-in-oil emulsion. Under the action of a pore-forming agent and alkali catalysis, a porous silica shell layer was formed. Under the mechanism of similar compatibility, the long-chain groups tended to face the paraffin region inside the sphere. The paraffin wax inside the sphere also protruded from the pores under the action of emulsification centrifugal force, thus forming a sea urchin-like structure. And in the carbon nanotube aqueous dispersion containing an emulsifier, through spray drying, the carbon nanotubes were adsorbed on the surface of the sea urchin-like composite spheres, and modified nanoparticles were prepared. On the one hand, the nano-silica in the nanoparticles can enhance the hardness and wear resistance of the wax film. The graphene-doped titanium dioxide and nano-zinc oxide have good photocatalytic antibacterial properties, improving the freshness preservation effect of the packaged contents; in addition to enhancing the antibacterial properties, they can also absorb ultraviolet rays to a certain extent, prevent the wax film from aging, and extend the service life of the packaging box. In addition, the paraffin spines in the sea urchin shape improve the compatibility of the carbon nanotubes and the compatibility with the paraffin matrix, thereby improving the compatibility and dispersibility of the modified nanoparticles. At the same time, they can form a rough structure with anti-slip properties and can also form tiny cavity channels to facilitate the discharge of air, accelerate air drying, and extend the shelf life.

[0029] The cold-resistant plasticizer added in the present invention, such as dioctyl adipate, etc., can effectively reduce the glass transition temperature of the wax film, making it still maintain good flexibility and antifreeze performance at low temperatures, and avoiding packaging failure caused by brittle fracture at low temperatures.

[0030] In the present invention, the wax matrix and other components are added into water, and a microemulsion is prepared through emulsification under the action of an emulsifier, making each component disperse more uniformly, greatly increasing the contact area and adhesion between the wax film and the packaging box, improving the coating quality and performance stability. At the same time, catalysts such as sodium chloride or potassium chloride are added, enabling the emulsified wax to rapidly undergo water-wax separation during rapid cooling, forming uneven leathery patterns, increasing roughness, having anti-slip properties, and at the same time forming air flow channels to facilitate the discharge of air, accelerating air drying, and extending the shelf life. In addition, the coating temperature of the blended wax composition for coating the packaging box is 90°C - 100°C, and the temperature difference is used to rapidly separate the emulsified wax into an aqueous phase and an oil phase, enhancing the waterproof effect.

[0031] The blended wax composition for coating the packaging box in the present invention has good waterproof, oxygen barrier, adhesion, and easy dyeing properties, good high and low temperature resistance, certain roughness after curing, good freshness preservation effect, can extend the shelf life, and has broad application prospects. Detailed implementation manners

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Graphene oxide, Xianfeng Nano, thickness 0.6 - 1.0 nm, number of layers 1 - 2, sheet diameter 10 - 50 μm, purity > 95 wt%; Carbon nanotubes, Xianfeng Nano, industrial multi-walled carbon nanotubes, length 10 - 30 microns, purity > 95%; Poly(2,5-furandicarboxylic acid-ethylene glycol) ester, Xi'an Qingshuo, content > 99%; Melted paraffin wax, Hebei Jianshuo Chemical Technology Co., Ltd., melting point 58 - 60 °C; Microcrystalline wax, Shandong Jinghao Chemical Co., Ltd., industrial grade, density 0.8 - 0.92 g / cm 3 ; Carnauba wax, Tianjin Dongli Lichang Chemical Co., Ltd., oil content < 0.2%, melting point 80 - 86 °C, penetration 0.3 mm.

[0034] Preparation Example 1 Preparation of Modified Furan Polyester

[0035] The method is as follows:

[0036] Add 10 g of poly(2,5-furandicarboxylic acid-ethylene glycol) ester to 200 mL of 1,1,2,2-tetrachloroethane, heat to 120 °C, stir to dissolve, after cooling, add 2 g of dodecyltrimethoxysilane, heat to 40 °C, stir and react for 3 h, add the product to ethanol, filter, wash, and dry to obtain the modified furan polyester.

[0037] Preparation Example 2 Preparation of Modified Furan Polyester

[0038] The method is as follows:

[0039] Add 10 g of poly(2,5-furandicarboxylic acid-ethylene glycol) ester to 200 mL of 1,1,2,2-tetrachloroethane, heat to 130 °C, stir to dissolve, after cooling, add 3 g of octadecyltriethoxysilane, heat to 50 °C, stir and react for 5 h, add the product to ethanol, filter, wash, and dry to obtain the modified furan polyester.

[0040] Preparation Example 3 Preparation of Modified Furan Polyester

[0041] The method is as follows:

[0042] 10 g of poly(ethylene 2,5-furandicarboxylate) was added to 200 mL of 1,1,2,2-tetrachloroethane, heated to 125 °C, stirred until dissolved, cooled, and then 2.5 g of dodecyltriethoxysilane was added. It was heated to 45 °C and stirred for reaction for 4 h. The product was added to ethanol, filtered, washed, and dried to obtain the modified furan polyester.

[0043] Preparation Example 4 Preparation of Modified Nanoparticles

[0044] The method is as follows:

[0045] S1. Preparation of modified TiO2 / ZnO nanocomposite: 8 g of tetrabutyl titanate and 4 g of zinc acetate were dissolved in 200 mL of ethanol, 150 mL of water was added, 7 g of citric acid and 3 g of concentrated hydrochloric acid were added, heated to 50 °C, stirred for reaction for 4 h, centrifuged, washed, dried, calcined at 500 °C for 1 h, the product was added to 5 g of 0.1 mg / mL graphene oxide aqueous dispersion, spray-dried, and reduced with hydrazine vapor for 5 h to obtain the modified TiO2 / ZnO nanocomposite;

[0046] S2. Preparation of sea urchin-shaped composite spheres: 10 g of dodecyltriethoxysilane was added to 200 ml of ethyl acetate to prepare the oil phase; 2 g of cetyltrimethylammonium bromide and 1 g of emulsifier were added to 100 mL of water to prepare the water phase; 4 g of molten paraffin (65 °C) and 2 g of modified TiO2 / ZnO nanocomposite were added to the water phase, emulsified at 6000 r / min for 15 min to form an emulsion suspension, the emulsion suspension was dropped into the oil phase, the pH value of the solution was adjusted to 10, emulsified at 8000 r / min for 10 min, and freeze-dried to obtain the sea urchin-shaped composite spheres;

[0047] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5;

[0048] S3. Preparation of modified nanoparticles: 1 g of sodium dodecylbenzenesulfonate was added to 150 mL of water, 4 g of carbon nanotubes and 12 g of sea urchin-shaped composite spheres were added, and spray-dried to obtain the modified nanoparticles.

[0049] Preparation Example 5 Preparation of Modified Nanoparticles

[0050] The method is as follows:

[0051] S1. Preparation of modified TiO2 / ZnO nanocomposite: Dissolve 12 g of tetrabutyl titanate and 6 g of zinc acetate in 200 mL of ethanol, add 150 mL of water, add 10 g of citric acid and 5 g of concentrated hydrochloric acid, heat to 70 °C, stir and react for 6 h, centrifuge, wash, dry, calcine at 600 °C for 3 h, add the product to 10 g of 0.2 mg / mL graphene oxide aqueous dispersion, spray dry, and reduce with hydrazine vapor for 7 h to obtain the modified TiO2 / ZnO nanocomposite;

[0052] S2. Preparation of sea urchin-like composite spheres: Add 15 g of n-octadecyltriethoxysilane to 200 ml of ethyl acetate to prepare an oil phase; add 3 g of cetyltrimethylammonium chloride and 2 g of emulsifier to 100 mL of water to prepare an aqueous phase; add 7 g of molten paraffin (65 °C) and 3 g of modified TiO2 / ZnO nanocomposite to the aqueous phase, emulsify at 8000 r / min for 25 min to form an emulsion suspension, drop the emulsion suspension into the oil phase, adjust the pH value of the solution to 11, emulsify at 10000 r / min for 20 min, and freeze-dry to obtain the sea urchin-like composite spheres;

[0053] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5;

[0054] S3. Preparation of modified nanoparticles: Add 2 g of sodium dodecyl sulfate to 150 mL of water, add 6 g of carbon nanotubes and 15 g of sea urchin-like composite spheres, and spray dry to obtain the modified nanoparticles.

[0055] Preparation Example 6 Preparation of modified nanoparticles

[0056] The method is as follows:

[0057] S1. Preparation of modified TiO2 / ZnO nanocomposite: Dissolve 10 g of tetrabutyl titanate and 5 g of zinc acetate in 200 mL of ethanol, add 150 mL of water, add 8 g of citric acid and 4 g of concentrated hydrochloric acid, heat to 60 °C, stir and react for 5 h, centrifuge, wash, dry, calcine at 550 °C for 2 h, add the product to 7 g of 0.15 mg / mL graphene oxide aqueous dispersion, spray dry, and reduce with hydrazine vapor for 6 h to obtain the modified TiO2 / ZnO nanocomposite;

[0058] S2. Preparation of sea urchin-like composite spheres: Add 12 g of dodecyltrimethoxysilane to 200 ml of ethyl acetate to obtain an oil phase; add 2.5 g of cetyltrimethylammonium bromide and 1.5 g of emulsifier to 100 mL of water to obtain an aqueous phase; add 5.5 g of molten paraffin (65 °C) and 2.5 g of modified TiO2 / ZnO nanocomposite to the aqueous phase, emulsify at 7000 r / min for 20 min to form an emulsion suspension, drop the emulsion suspension into the oil phase, adjust the pH value of the solution to 10.5, emulsify at 9000 r / min for 15 min, and freeze-dry to obtain sea urchin-like composite spheres;

[0059] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5;

[0060] S3. Preparation of modified nanoparticles: Add 1.5 g of sodium dodecylsulfonate to 150 mL of water, add 5 g of carbon nanotubes and 13 g of sea urchin-like composite spheres, and spray-dry to obtain modified nanoparticles.

[0061] Comparative Preparation Example 1

[0062] Compared with Preparation Example 6, the difference lies in that zinc acetate was not added in step S1.

[0063] Specifically as follows:

[0064] S1. Preparation of modified TiO2 nanocomposite: Dissolve 15 g of tetrabutyl titanate in 200 mL of ethanol, add 150 mL of water, add 8 g of citric acid and 4 g of concentrated hydrochloric acid, heat to 60 °C, stir and react for 5 h, centrifuge, wash, dry, calcine at 550 °C for 2 h, add the product to 7 g of 0.15 mg / mL graphene oxide aqueous dispersion, spray-dry, and reduce with hydrazine vapor for 6 h to obtain a modified TiO2 nanocomposite.

[0065] Comparative Preparation Example 2

[0066] Compared with Preparation Example 6, the difference lies in that it was not added to the graphene oxide aqueous dispersion in step S1.

[0067] Specifically as follows:

[0068] S1. Preparation of TiO2 / ZnO nanocomposite: Dissolve 10 g of tetrabutyl titanate and 5 g of zinc acetate in 200 mL of ethanol, add 150 mL of water, add 8 g of citric acid and 4 g of concentrated hydrochloric acid, heat to 60 °C, stir and react for 5 h, centrifuge, wash, dry, and calcine at 550 °C for 2 h to obtain a TiO2 / ZnO nanocomposite.

[0069] Comparative Preparation Example 3

[0070] Compared with Preparation Example 6, the difference lies in that molten paraffin was not added in Step S2.

[0071] Specifically as follows:

[0072] S2. Preparation of composite spheres: Add 12 g of dodecyltrimethoxysilane to 200 ml of ethyl acetate to obtain an oil phase; add 2.5 g of cetyltrimethylammonium bromide and 1.5 g of an emulsifier to 100 mL of water to obtain an aqueous phase; add 2.5 g of modified TiO2 / ZnO nanocomposite to the aqueous phase, emulsify at 7000 r / min for 20 min to form a suspension, add the suspension dropwise to the oil phase, adjust the pH value of the solution to 10.5, emulsify at 9000 r / min for 15 min, and freeze-dry to obtain composite spheres;

[0073] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5.

[0074] Comparative Preparation Example 4

[0075] Compared with Preparation Example 6, the difference lies in that the modified TiO2 / ZnO nanocomposite was not added in Step S2.

[0076] Specifically as follows:

[0077] S2. Preparation of sea urchin-shaped composite spheres: Add 12 g of dodecyltrimethoxysilane to 200 ml of ethyl acetate to obtain an oil phase; add 2.5 g of cetyltrimethylammonium bromide and 1.5 g of an emulsifier to 100 mL of water to obtain an aqueous phase; add 5.5 g of molten paraffin (65 °C) to the aqueous phase, emulsify at 7000 r / min for 20 min to form an emulsion, add the emulsion dropwise to the oil phase, adjust the pH value of the solution to 10.5, emulsify at 9000 r / min for 15 min, and freeze-dry to obtain sea urchin-shaped composite spheres;

[0078] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5.

[0079] Comparative Preparation Example 5

[0080] Compared with Preparation Example 6, the difference lies in that Step S3 was not carried out.

[0081] Specifically as follows:

[0082] S1. Preparation of modified TiO2 / ZnO nanocomposite: Dissolve 10 g of tetrabutyl titanate and 5 g of zinc acetate in 200 mL of ethanol, add 150 mL of water, add 8 g of citric acid and 4 g of concentrated hydrochloric acid, heat to 60 °C, stir and react for 5 h, centrifuge, wash, dry, calcine at 550 °C for 2 h, add the product to 7 g of graphene oxide aqueous dispersion with a concentration of 0.15 mg / mL, spray dry, and reduce it with hydrazine vapor for 6 h to obtain the modified TiO2 / ZnO nanocomposite;

[0083] S2. Preparation of sea urchin-like composite spheres: Add 12 g of dodecyltrimethoxysilane to 200 ml of ethyl acetate to obtain the oil phase; add 2.5 g of cetyltrimethylammonium bromide and 1.5 g of emulsifier to 100 mL of water to obtain the aqueous phase; add 5.5 g of molten paraffin (65 °C) and 2.5 g of modified TiO2 / ZnO nanocomposite to the aqueous phase, emulsify at 7000 r / min for 20 min to form an emulsion suspension, drop the emulsion suspension into the oil phase, adjust the pH value of the solution to 10.5, emulsify at 9000 r / min for 15 min, and freeze-dry to obtain the sea urchin-like composite spheres, which are the modified nanoparticles;

[0084] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5.

[0085] Example 1

[0086] This example provides a blended wax composition for box packaging coating, including the following steps:

[0087] Heat 50 g of paraffin wax, 10 g of microcrystalline wax, 5 g of carnauba wax, 10 g of the modified furan polyester prepared in Preparation Example 1, 2 g of dioctyl adipate, and 0.5 g of antioxidant 1010 to 120 °C, stir and mix evenly to obtain Phase A;

[0088] The paraffin wax consists of No. 56 paraffin wax and No. 64 paraffin wax with a mass ratio of 40:15;

[0089] Add 1 g of emulsifier and 3 g of sodium chloride to 70 g of water, stir and mix evenly to obtain Phase B;

[0090] The emulsifier is a mixture of Tween-80 and Span-80 with a mass ratio of 3:5;

[0091] Add Phase B to Phase A, add 5 g of the modified nanoparticles prepared in Preparation Example 4, heat to 70 °C, and emulsify at 8000 - 10000 r / min for 10 min to obtain the blended wax composition for box packaging coating.

[0092] Example 2

[0093] This embodiment provides a blended wax composition for packaging box coating, comprising the following steps:

[0094] (1) Heat 70 g of paraffin wax, 15 g of microcrystalline wax, 10 g of carnauba wax, 20 g of the modified furan polyester prepared in Preparation Example 2, 4 g of dioctyl adipate, and 1 g of antioxidant 1010 to 140 °C, and stir and mix evenly to obtain Phase A;

[0095] The paraffin wax consists of No. 56 paraffin wax and No. 64 paraffin wax, and the mass ratio is 50:25;

[0096] (2) Add 3 g of emulsifier and 5 g of potassium chloride to 80 g of water, and stir and mix evenly to obtain Phase B;

[0097] The emulsifier is a mixture of Tween-80 and Span-80, and the mass ratio is 3:5;

[0098] Add Phase B to Phase A, add 10 g of the modified nanoparticles prepared in Preparation Example 5, heat to 90 °C, and emulsify at 10000 r / min for 20 min to obtain the blended wax composition for packaging box coating.

[0099] Example 3

[0100] This embodiment provides a blended wax composition for packaging box coating, comprising the following steps:

[0101] (1) Heat 60 g of paraffin wax, 12 g of microcrystalline wax, 7 g of carnauba wax, 15 g of the modified furan polyester prepared in Preparation Example 3, 3 g of dioctyl adipate, and 0.7 g of antioxidant 1010 to 130 °C, and stir and mix evenly to obtain Phase A;

[0102] The paraffin wax consists of No. 56 paraffin wax and No. 64 paraffin wax, and the mass ratio is 45:20;

[0103] (2) Add 2 g of emulsifier and 4 g of sodium chloride to 75 g of water, and stir and mix evenly to obtain Phase B;

[0104] The emulsifier is a mixture of Tween-80 and Span-80, and the mass ratio is 3:5;

[0105] (3) Add Phase B to Phase A, add 7 g of the modified nanoparticles prepared in Preparation Example 6, heat to 80 °C, and emulsify at 9000 r / min for 15 min to obtain the blended wax composition for packaging box coating.

[0106] Comparative Example 1

[0107] Compared with Example 3, the difference is that the modified furan polyester is not added.

[0108] Comparative Example 2

[0109] Compared with Example 3, the difference lies in that the modified nanoparticles are prepared from Comparative Preparation Example 1.

[0110] Comparative Example 3

[0111] Compared with Example 3, the difference lies in that the modified nanoparticles are prepared from Comparative Preparation Example 2.

[0112] Comparative Example 4

[0113] Compared with Example 3, the difference lies in that the modified nanoparticles are prepared from Comparative Preparation Example 3.

[0114] Comparative Example 5

[0115] Compared with Example 3, the difference lies in that the modified nanoparticles are prepared from Comparative Preparation Example 4.

[0116] Comparative Example 6

[0117] Compared with Example 3, the difference lies in that the modified nanoparticles are prepared from Comparative Preparation Example 5.

[0118] Comparative Example 7

[0119] Compared with Example 3, the difference lies in that no modified nanoparticles are added.

[0120] Comparative Example 8

[0121] Compared with Example 3, the difference lies in that no sodium chloride is added.

[0122] Comparative Example 9

[0123] Compared with Example 3, the difference lies in that no Phase B is added.

[0124] Specifically as follows:

[0125] (1) Heat 60 g of paraffin wax, 12 g of microcrystalline wax, 7 g of carnauba wax, 3 g of dioctyl adipate, and 0.7 g of antioxidant 1010 to 120 °C, stir and mix evenly to obtain Phase A;

[0126] The paraffin wax consists of No. 56 paraffin wax and No. 64 paraffin wax, and the mass ratio is 45:20;

[0127] Add 7 g of the modified nanoparticles prepared in Preparation Example 6 and 15 g of the modified furan polyester prepared in Preparation Example 3 to Phase A, heat to 170 °C, stir and mix evenly to obtain the blended wax composition for coating the packaging box.

[0128] Test Example 1

[0129] The same cardboard was prepared, and the waxing treatment was carried out using the blending wax compositions for coating of the packaging boxes prepared in Examples 1-3 and Comparative Examples 1-9 respectively, and then the performance tests were carried out. The results are shown in Table 1. The storage stability is the time for observing the sedimentation after sealing the blending wax composition for coating of the packaging box, and the storage temperature is 4°C.

[0130] Table 1

[0131] ;

[0132] As can be seen from the above table, the blending wax compositions for coating of the packaging boxes prepared in Examples 1-3 of the present invention have better comprehensive performance.

[0133] Test Example 2

[0134] The same cardboard was prepared, and the waxing treatment was carried out using the blending wax compositions for coating of the packaging boxes prepared in Examples 1-3 and Comparative Examples 1-9 respectively, and then the performance tests were carried out. The results are shown in Table 2. The unwaxed cardboard was used as the control group.

[0135] Oxygen permeability test: The instrument used was an oxygen permeation meter. The cardboard was fixed on the workbench. When testing, the upper chamber flow rate of the oxygen permeation meter was set to 20 mL / min, the lower chamber flow rate was set to 10 mL / min, and zero blowing was carried out for 2 hours to make the zero point stable below 5 PPM to complete the zero point determination; then the upper chamber flow rate was controlled to 20 mL / min, and the test was carried out for another 4 hours. According to the test results, the oxygen permeation amount (mL / m 2 •day•0.1 MPa) was calculated.

[0136] Antibacterial property test: The antibacterial effect of the prepared waxed cardboard was tested according to QBT2591-2003 "Antibacterial Plastics - Test Methods for Antibacterial Properties and Antibacterial Effects".

[0137] Table 2

[0138] ;

[0139] As can be seen from the above table, the blending wax compositions for coating of the packaging boxes prepared in Examples 1-3 of the present invention have good oxygen barrier effect after coating and have good antibacterial property.

[0140] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A blended wax composition for coating a packaging box, characterized in that: The preparation raw materials include the following components by weight: 50-70 parts of paraffin wax, 10-15 parts of microcrystalline wax, 5-10 parts of natural bio-based wax, 2-4 parts of cold-resistant plasticizer, 10-20 parts of modified furan polyester, 5-10 parts of modified nanoparticles, 0.5-1 part of antioxidant, 1-3 parts of emulsifier, 70-80 parts of water, and 3-5 parts of catalyst; the modified furan polyester is poly (2,5-furandicarboxylic acid-ethylene glycol) ester modified by a silane coupling agent, and the modified nanoparticles are graphene-coated TiO2 / ZnO nanocomposites, which are then added with molten paraffin, emulsified to form sea urchin-shaped composite balls, which are then mixed with the emulsifier and carbon nanotubes and spray-dried to obtain the modified nanoparticles.

2. The prepared wax composition for packaging box coating according to claim 1, characterized in that: The cold-resistant plasticizer is dioctyl adipate, and the catalyst is sodium chloride or potassium chloride; the paraffin wax is composed of No. 56 paraffin and No. 64 paraffin, with a mass ratio of 40-50:15-25; the natural bio-based wax is selected from at least one of carnauba wax and candelilla wax; and the antioxidant is antioxidant 1010.

3. The prepared wax composition for packaging box coating according to claim 1, characterized in that: The preparation method of the modified furan polyester is as follows: Poly(2,5-furandicarboxylic acid-ethylene glycol) ester is added to 1,1,2,2-tetrachloroethane, heated to dissolve, cooled, and then a long-chain alkyl silane coupling agent is added. The mixture is heated and stirred to react. The product is added to ethanol, filtered, washed, and dried to obtain a modified furan polyester.

4. The prepared wax composition for packaging box coating according to claim 3, characterized in that: The mass ratio of the poly(ethylene glycol-2,5-furandicarboxylate) ester to the long-chain alkyl silane coupling agent is 10:2-3, and the long-chain alkyl silane coupling agent is selected from at least one of n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, n-dodecyltrimethoxysilane, and n-octadecyltrimethoxysilane. The temperature for heating and dissolving is 120-130° C., the temperature for heating and stirring the reaction is 40-50° C., and the time is 3-5 hours.

5. The prepared wax composition for packaging box coating according to claim 1, characterized in that: The preparation method of the modified nanoparticles is as follows: S1. Preparation of a modified TiO2 / ZnO nanocomposite: Tetrabutyl titanate and zinc acetate were dissolved in ethanol, added to water, and citric acid and concentrated hydrochloric acid were added. The mixture was heated with stirring to react, centrifuged, washed, dried, and calcined. The product was then added to an aqueous dispersion of graphene oxide, spray-dried, and reduced with hydrazine hydrate vapor to obtain a modified TiO2 / ZnO nanocomposite. S2. Preparation of sea urchin-shaped composite spheres: Long-chain alkylsilane is added to an organic solvent to prepare an oil phase; a porogen and an emulsifier are added to water to prepare an aqueous phase; molten paraffin and a modified TiO2 / ZnO nanocomposite are added to the aqueous phase, emulsified for the first time to form an emulsion suspension, which is then added dropwise to the oil phase. The pH of the solution is adjusted, emulsified for a second time, and freeze-dried to produce sea urchin-shaped composite spheres; S3. Preparation of modified nanoparticles: An emulsifier is added to water, and carbon nanotubes and sea urchin-shaped composite spheres are added thereto, followed by spray drying to obtain modified nanoparticles.

6. The prepared wax composition for coating packaging boxes according to claim 5, characterized in that: The mass ratio of tetrabutyl titanate, zinc acetate, citric acid, concentrated hydrochloric acid, and graphene oxide aqueous dispersion in step S1 is 8-12:4-6:7-10:3-5:5-10, the concentration of the graphene oxide aqueous dispersion is 0.1-0.2 mg / mL, the calcination temperature is 500-600°C, the time is 1-3h, the heating and stirring reaction temperature is 50-70°C, the time is 4-6h, and the reduction time is 5-7h.

7. The prepared wax composition for coating packaging boxes according to claim 5, characterized in that: In step S2, the long-chain alkylsilane is selected from at least one of n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, n-dodecyltrimethoxysilane, and n-octadecyltrimethoxysilane; the porogen is selected from at least one of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, and cetyldimethylbenzylammonium chloride; the emulsifier is selected from Tween-20, Tween-40, Tween-60, Tween-80, Span-20, Span-40, Span-60, At least one of Span-80, the mass ratio of the long-chain alkyl silane, porogen, emulsifier, paraffin and modified TiO2 / ZnO nanocomposite is 10-15:2-3:1-2:4-7:2-3, the rotation speed of the first emulsification is 6000-8000r / min, the time is 15-25min, the pH value of the solution is adjusted to 10-11, the rotation speed of the second emulsification is 8000-10000r / min, and the time is 10-20min.

8. The prepared wax composition for coating packaging boxes according to claim 5, characterized in that: In step S3, the emulsifier is selected from at least one of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and sodium dodecylsulfonate, and the mass ratio of the emulsifier, carbon nanotubes, and sea urchin-shaped composite balls is 1-2:4-6:12-15.

9. A method for preparing the blended wax composition for coating packaging boxes according to any one of claims 1 to 8, characterized in that: The following steps are involved: Heat and mix paraffin wax, microcrystalline wax, natural bio-based wax, modified furan polyester, cold-resistant plasticizer, and antioxidant to obtain phase A; Add the emulsifier and catalyst into water and stir to mix well to obtain phase B; Phase B is added to phase A, modified nanoparticles are added, and the mixture is heated and emulsified to prepare a blended wax composition for coating packaging boxes.

10. The preparation method according to claim 9, characterized in that The temperature of the heating and mixing in step (1) is 120-140° C., the temperature of the heating and emulsification in step (3) is 70-90° C., the rotation speed of the emulsification is 8000-10000 r / min, and the time is 10-20 min.