Cold insulation waterproof carton and preparation method thereof

Abstract

The invention relates to the technical field of cartons. The invention discloses a cold insulation waterproof carton and a preparation method thereof. The cold insulation waterproof carton comprises a surface paper layer, a kt board layer and a silver paperboard layer which are sequentially attached. The kt board layer and the silver card paper layer are attached through an adhesive. The adhesive is prepared from the following raw materials in parts by weight: 50 to 70 parts of polyvinyl acetate emulsion, 10 to 30 parts of acrylate copolymer emulsion, 5 to 12.5 parts of expanded perlite, 2 to 5 parts of glucomannan, 1 to 3 parts of cross-linking agent, 0.1 to 0.5 part of preservative, 0.1 to 0.5 part of flatting agent and 1 to 5 parts of flame retardant, wherein the acrylate copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methylacrylate, an initiator, an emulsifier and water. The cold-insulation waterproof carton prepared by the invention is excellent in heat insulation effect and waterproof effect.

Description

Technical Field

[0001] The present application relates to the field of carton technology, and in particular to a cold-insulating and waterproof carton and a preparation method thereof. Background Art

[0002] With the rapid development of the cold chain logistics industry, the demand for packaging materials that can maintain the temperature of goods in low-temperature environments and have good waterproof properties is growing. Especially for sensitive goods such as cold drinks, frozen foods, fresh products, and medicines that need to be refrigerated, suitable packaging is one of the key factors to ensure their quality and safety during transportation and storage. Although traditional cartons are low-cost and easy to recycle, due to their structural and material limitations, it is difficult to simultaneously meet the requirements of efficient cold preservation and good waterproof performance.

[0003] There are many types of cold-keeping packaging solutions on the market, among which KT boards (such as polystyrene foam) are widely used in the field of cold chain transportation due to their excellent thermal insulation properties. However, although these materials perform well in maintaining low-temperature environments, they usually do not have sufficient waterproof capabilities. In addition, existing KT boards are relatively brittle, easily creased, and have low strength, making them unsuitable for direct production of thermal insulation boxes. On the other hand, cartons specially designed to improve waterproofness often achieve this by coating the surface with special materials or using treated facial paper, but this often sacrifices the cold-keeping effect of the cartons.

[0004] Therefore, there is an urgent need to develop a cold-insulating and waterproof carton with excellent thermal insulation and waterproof effects. Summary of the invention

[0005] In order to solve at least one of the above technical problems, a cold-insulating and waterproof carton with excellent thermal insulation and waterproof effects is developed. The present application provides a cold-insulating and waterproof carton and a preparation method thereof.

[0006] On the one hand, the present application provides a cold-insulating and waterproof carton, comprising a face paper layer, a KT board layer and a silver card paper layer laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; The raw material composition of the adhesive includes, by weight: 50-70 parts of polyvinyl acetate emulsion, 10-30 parts of acrylate copolymer emulsion, 5-12.5 parts of expanded perlite, 2-5 parts of glucomannan, 1-3 parts of cross-linking agent, 0.1-0.5 parts of preservative, 0.1-0.5 parts of leveling agent, and 1-5 parts of flame retardant; The acrylic copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, an initiator, an emulsifier and water, and the weight ratio of methyl methacrylate, hydroxyethyl methacrylate, an initiator, an emulsifier and water is 30-50:5-15:0.1-1:1-3:40-50.

[0007] By adopting the above technical solution, the cold-insulating and waterproof carton provided by the present application achieves good thermal insulation effect and waterproof performance through the multi-layer structure design and the application of special adhesives. This multi-layer structure can give full play to the advantages of each material, thereby achieving the best balance of comprehensive performance. The surface paper layer of the present application can provide appearance protection and certain mechanical strength, the KT board layer has excellent thermal insulation performance and can effectively maintain the internal low temperature environment, and the silver card paper layer has a metallic luster and moisture-proof performance, which can further enhance the waterproof effect.

[0008] In the adhesive of the present application, polyvinyl acetate emulsion and acrylic copolymer emulsion can provide good bonding performance and flexibility. Expanded perlite can improve thermal insulation performance and enhance thermal insulation effect. Glucomannan can increase the viscosity and stability of the adhesive. The cross-linking agent forms a three-dimensional network structure through chemical cross-linking, thereby improving the water resistance and mechanical strength of the adhesive. The preservative can prevent the adhesive from mildewing during storage. The leveling agent can improve the coating performance of the adhesive, making it more uniform and avoiding bubbles or other defects. The flame retardant can improve the fire resistance of the adhesive and increase safety.

[0009] The expanded perlite and glucomannan in this application work together to improve thermal insulation performance, increase thermal insulation effect, form multiple thermal insulation barriers with the KT board layer, and significantly improve the overall cold preservation performance. The KT board layer and expanded perlite in this application work together to provide excellent thermal insulation performance and effectively maintain the internal low temperature environment. It also improves the mechanical strength of the carton and is not easy to crease. The silver card paper layer and adhesive work together to provide excellent waterproof performance to prevent external moisture penetration.

[0010] Optionally, the surface paper layer is selected from one of kraft paper, white cardboard, laminated paper and coated paper.

[0011] By adopting the above technical solution, the carton of the present application can select a suitable surface paper layer according to different application scenarios, which can better meet specific functional requirements. By selecting a surface paper layer that matches the brand image, the market appeal of the product can be improved and consumers' awareness of the brand can be enhanced.

[0012] Optionally, the kt board layer is made of polystyrene.

[0013] By adopting the above technical solutions, polystyrene has excellent thermal insulation properties, and its closed-cell structure can effectively prevent heat transfer, which means that it can keep the internal temperature stable, whether it is to prevent external heat from entering or to maintain a low temperature environment inside. This closed-cell structure also has a certain moisture-proof ability. When combined with the waterproof surface paper layer, the entire package can better resist moisture penetration. In addition, polystyrene foam is very light, which helps to reduce transportation costs and is easy to handle and handle.

[0014] Optionally, the kt board layer has a thickness of 3 to 8 mm.

[0015] By adopting the above technical solution, within the thickness range of the kt board layer of the present application, the polystyrene foam can provide sufficient heat insulation effect, effectively isolate the influence of external temperature changes on the internal items, and ensure that the carton has sufficient rigidity and pressure resistance to protect the internal items from damage. If it is too thin, it may not achieve a good heat insulation effect; if it is too thick, it will increase unnecessary material and transportation costs.

[0016] Optionally, the preparation method of the acrylic copolymer emulsion is: stir and mix the methyl methacrylate, hydroxyethyl methacrylate, half of the emulsifier and half of the water to obtain a pre-emulsion; heat the remaining water and emulsifier, add half of the initiator, mix, and obtain a seed emulsion; drop the pre-emulsion into the seed emulsion, add the remaining initiator, keep the mixture warm for 1 to 2 hours under stirring, cool to room temperature, filter, and obtain the acrylic copolymer emulsion.

[0017] Optionally, the weight ratio of the expanded perlite to glucomannan is 2-3:1.

[0018] By adopting the above technical solution, the porous structure of the expanded perlite of the present application can absorb a certain amount of water, and after absorbing water, the volume expands to form a physical barrier to prevent further water penetration; at the same time, the thickening effect of glucomannan can make the adhesive fill the tiny gaps of the carton more tightly, further enhancing the waterproof effect. The expanded perlite also provides good thermal insulation performance, and glucomannan helps the adhesive to better adhere to the kt board layer and other materials, forming a tighter, seamless protective layer, thereby further improving the thermal insulation effect.

[0019] Optionally, the cross-linking agent is selected from at least one of diphenylmethane diisocyanate, bisphenol A epoxy resin and tetrabutyl titanate.

[0020] Optionally, the preservative is selected from at least one of kasone, benzisothiazolinone and potassium sorbate.

[0021] By adopting the above technical solution, the preservative of the present application can prevent the growth of microorganisms in the adhesive and ensure its stability and durability during storage and use.

[0022] Optionally, the flame retardant is selected from at least one of aluminum hydroxide, trimethyl phosphate and urea.

[0023] By adopting the above technical solution, the flame retardant of the present application can improve the fire resistance of the material, ensuring that the spread of flames can be slowed down or prevented when encountering a fire source, thereby improving the safety of the cold-insulating and waterproof carton.

[0024] In a second aspect, the present application provides a method for preparing the above-mentioned cold-insulating and waterproof carton, comprising the following steps: S1, mixing the polyvinyl acetate emulsion and the acrylate copolymer emulsion to prepare a premixed liquid; S2, sequentially adding the glucomannan, expanded perlite, cross-linking agent, preservative, leveling agent, and flame retardant to the premixed liquid, filtering, and obtaining the adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain the kt board; S4, spraying the adhesive on one side of the kt board, attaching the silver card paper, drying, and curing; S5, spray the adhesive on the other side of the kt board, adhere the surface paper, dry, and solidify to obtain a cold-insulating and waterproof board; S6, use a die-cutting machine to cut the cold-insulating and waterproof board into a required shape, press out line marks, and finally fold and combine to obtain a cold-insulating and waterproof carton.

[0025] By adopting the above technical solution, the preparation method adopted in this application has a simple process, convenient operation, and improved production efficiency. The preparation method of this application achieves the combination of efficient heat preservation and good waterproof performance through the composite of multi-layer materials and the application of special adhesives. Each step is aimed at optimizing the functional characteristics of the carton, forming a complete production process from basic bonding to final molding.

[0026] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The cold-insulating and waterproof carton provided in this application achieves good thermal insulation effect and waterproof performance through multi-layer structure design and application of special adhesives.

[0027] 2. The expanded perlite and glucomannan in the present application work together to improve the thermal insulation performance, increase the thermal insulation effect, form multiple thermal insulation barriers with the KT board layer, and significantly improve the overall cold preservation performance.

[0028] 3. The preparation method adopted in this application has a simple process, is easy to operate, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a cold-keeping and waterproof carton; Figure 2 This is a schematic diagram of the layered structure of a cold-insulating and waterproof carton; Description of reference numerals: 1. surface paper layer; 2. kt board layer; 3. silver card paper layer. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0031] The present application designs a cold-insulating and waterproof carton, comprising a face paper layer, a KT board layer and a silver card paper layer laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; The raw material composition of the adhesive includes, by weight: 50-70 parts of polyvinyl acetate emulsion, 10-30 parts of acrylate copolymer emulsion, 5-12.5 parts of expanded perlite, 2-5 parts of glucomannan, 1-3 parts of cross-linking agent, 0.1-0.5 parts of preservative, 0.1-0.5 parts of leveling agent, and 1-5 parts of flame retardant; The acrylic copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, an initiator, an emulsifier and water, and the weight ratio of methyl methacrylate, hydroxyethyl methacrylate, an initiator, an emulsifier and water is 30-50:5-15:0.1-1:1-3:40-50.

[0032] The cold-insulating and waterproof carton of the present application is prepared by the following method, including the following steps: S1, mixing the polyvinyl acetate emulsion and the acrylate copolymer emulsion to prepare a premixed liquid; S2, sequentially adding the glucomannan, expanded perlite, cross-linking agent, preservative, leveling agent, and flame retardant to the premixed liquid, filtering, and obtaining the adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain the kt board; S4, spraying the adhesive on one side of the kt board, attaching the silver card paper, drying, and curing; S5, spray the adhesive on the other side of the kt board, adhere the surface paper, dry, and solidify to obtain a cold-insulating and waterproof board; S6, use a die-cutting machine to cut the cold-insulating and waterproof board into a required shape, press out line marks, and finally fold and combine to obtain a cold-insulating and waterproof carton.

[0033] The applicant has designed the technical solution of the present application to address the problem that existing cartons are difficult to simultaneously meet the requirements of efficient cold-keeping effect and good waterproof performance.

[0034] The raw materials used in this application are as follows: Polyvinyl acetate emulsion: CAS: 9003-20-7.

[0035] Methyl methacrylate: CAS: 80-62-6.

[0036] Hydroxyethyl methacrylate: CAS: 868-77-9.

[0037] Ammonium persulfate: CAS: 7727-54-0.

[0038] Sodium dodecyl sulfate: CAS: 151-21-3.

[0039] Expanded perlite: CAS: 93763-70-3.

[0040] Glucomannan: CAS: 11078-31-2.

[0041] Methylene diphenyl diisocyanate: CAS: 101-68-8.

[0042] Tetrabutyl titanate: CAS: 3087-39-6.

[0043] CAS: CAS: 26172-55-4.

[0044] Benzisothiazolinone: CAS: 2634-33-5.

[0045] Polydimethylsiloxane: CAS: 9016-00-6.

[0046] Trimethyl phosphate: CAS: 512-56-1.

[0047] Urea: CAS: 57-13-6. Specific embodiments

[0048] Examples 1 to 3 Example 1 The present embodiment provides a cold-insulating and waterproof carton, comprising a face paper layer, a KT board layer and a silver card paper layer laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; the face paper layer is kraft paper, and the KT board layer is made of polystyrene with a thickness of 5 mm.

[0049] The raw material composition of the adhesive includes, by weight: 50 parts of polyvinyl acetate emulsion, 30 parts of acrylate copolymer emulsion, 5 parts of expanded perlite, 2 parts of glucomannan, 3 parts of cross-linking agent, 0.5 parts of preservative, 0.1 parts of leveling agent, and 5 parts of flame retardant; Among them, the cross-linking agent is diphenylmethane diisocyanate, the preservative is kason, the leveling agent is polydimethylsiloxane, and the flame retardant is trimethyl phosphate.

[0050] The acrylic copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, initiator, emulsifier and water in a weight ratio of 30:5:0.1:1:40; the initiator is ammonium persulfate and the emulsifier is sodium dodecyl sulfate; The preparation method of the acrylic copolymer emulsion is as follows: methyl methacrylate, hydroxyethyl methacrylate, half of the emulsifier and half of the water are stirred and mixed to obtain a pre-emulsion; the remaining water and the emulsifier are heated, half of the initiator is added, and the mixture is mixed to obtain a seed emulsion; the pre-emulsion is dripped into the seed emulsion, the remaining initiator is added, the mixture is heated and reacted for 1.5 hours under stirring, the mixture is cooled to room temperature, and the mixture is filtered to obtain the acrylic copolymer emulsion.

[0051] The method for preparing the cold-insulating and waterproof carton comprises the following steps: S1, mixing polyvinyl acetate emulsion and acrylate copolymer emulsion to prepare a premixed liquid; S2. Add glucomannan, expanded perlite, a cross-linking agent, a preservative, a leveling agent, and a flame retardant to the premixed liquid in sequence, and filter to obtain an adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain a kt board; S4, spray the adhesive on one side of the kt board, attach the silver card paper, dry and cure; S5, spray adhesive on the other side of the kt board, attach the surface paper, dry and solidify, and obtain a cold-insulating and waterproof board; S6. Use a die-cutting machine to cut the cold-insulating and waterproof board into the required shape, press out the line marks, and finally fold and combine them to make a cold-insulating and waterproof carton.

[0052] Example 2 The present embodiment provides a cold-insulating and waterproof carton, comprising a face paper layer, a KT board layer and a silver card paper layer laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; the face paper layer is kraft paper, and the KT board layer is made of polystyrene with a thickness of 5 mm.

[0053] The raw material composition of the adhesive includes, by weight: 60 parts of polyvinyl acetate emulsion, 20 parts of acrylate copolymer emulsion, 8.7 parts of expanded perlite, 3.5 parts of glucomannan, 2 parts of cross-linking agent, 0.3 parts of preservative, 0.3 parts of leveling agent, and 3 parts of flame retardant; Among them, the cross-linking agent is diphenylmethane diisocyanate, the preservative is kason, the leveling agent is polydimethylsiloxane, and the flame retardant is trimethyl phosphate.

[0054] The acrylate copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, initiator, emulsifier and water in a weight ratio of 40:10:0.5:2:45; the initiator is ammonium persulfate and the emulsifier is sodium dodecyl sulfate; the preparation method of the acrylate copolymer emulsion is: methyl methacrylate, hydroxyethyl methacrylate, half of the emulsifier and half of the water are stirred and mixed to prepare a pre-emulsion; the remaining water and emulsifier are heated, half of the initiator is added, and the mixture is mixed to prepare a seed emulsion; the pre-emulsion is dripped into the seed emulsion, the remaining initiator is added, the mixture is heated and reacted for 1.5 hours under stirring, the mixture is cooled to room temperature, and the mixture is filtered to prepare the acrylate copolymer emulsion.

[0055] The method for preparing the cold-insulating and waterproof carton comprises the following steps: S1, mixing polyvinyl acetate emulsion and acrylate copolymer emulsion to prepare a premixed liquid; S2. Add glucomannan, expanded perlite, a cross-linking agent, a preservative, a leveling agent, and a flame retardant to the premixed liquid in sequence, and filter to obtain an adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain a kt board; S4, spray the adhesive on one side of the kt board, attach the silver card paper, dry and cure; S5, spray adhesive on the other side of the kt board, attach the surface paper, dry and solidify, and obtain a cold-insulating and waterproof board; S6. Use a die-cutting machine to cut the cold-insulating and waterproof board into the required shape, press out the line marks, and finally fold and combine them to make a cold-insulating and waterproof carton.

[0056] Example 3 The present embodiment provides a cold-insulating and waterproof carton, comprising a face paper layer, a KT board layer and a silver card paper layer laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; the face paper layer is kraft paper, and the KT board layer is made of polystyrene with a thickness of 5 mm.

[0057] The raw material composition of the adhesive includes, by weight: 70 parts of polyvinyl acetate emulsion, 10 parts of acrylate copolymer emulsion, 12.5 parts of expanded perlite, 5 parts of glucomannan, 1 part of cross-linking agent, 0.1 parts of preservative, 0.5 parts of leveling agent, and 1 part of flame retardant; Among them, the cross-linking agent is diphenylmethane diisocyanate, the preservative is kason, the leveling agent is polydimethylsiloxane, and the flame retardant is trimethyl phosphate.

[0058] The acrylic copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, initiator, emulsifier and water in a weight ratio of 50:15:1:3:50; the initiator is ammonium persulfate and the emulsifier is sodium dodecyl sulfate; The preparation method of the acrylic copolymer emulsion is as follows: methyl methacrylate, hydroxyethyl methacrylate, half of the emulsifier and half of the water are stirred and mixed to obtain a pre-emulsion; the remaining water and the emulsifier are heated, half of the initiator is added, and the mixture is mixed to obtain a seed emulsion; the pre-emulsion is dripped into the seed emulsion, the remaining initiator is added, the mixture is heated and reacted for 1.5 hours under stirring, the mixture is cooled to room temperature, and the mixture is filtered to obtain the acrylic copolymer emulsion.

[0059] The method for preparing the cold-insulating and waterproof carton comprises the following steps: S1, mixing polyvinyl acetate emulsion and acrylate copolymer emulsion to prepare a premixed liquid; S2. Add glucomannan, expanded perlite, a cross-linking agent, a preservative, a leveling agent, and a flame retardant to the premixed liquid in sequence, and filter to obtain an adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain a kt board; S4, spray the adhesive on one side of the kt board, attach the silver card paper, dry and cure; S5, spray adhesive on the other side of the kt board, attach the surface paper, dry and solidify, and obtain a cold-insulating and waterproof board; S6. Use a die-cutting machine to cut the cold-insulating and waterproof board into the required shape, press out the line marks, and finally fold and combine them to make a cold-insulating and waterproof carton.

[0060] Comparative Examples 1 to 4 Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that no acrylic copolymer emulsion is added to the adhesive of Comparative Example 1.

[0061] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that no expanded perlite is added to the adhesive of Comparative Example 2.

[0062] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that no glucomannan is added to the adhesive of Comparative Example 3.

[0063] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that expanded perlite and glucomannan are not added to the adhesive of Comparative Example 4.

[0064] Experimental testing Test items and test methods Strength: Cut the carton board into 40×20cm size, hang it in the air, and then place objects with increasing weight on the carton board in turn, observe whether the carton board bends, and record the maximum weight of the carton board without bending.

[0065] Heat preservation effect: Place 6 ice packs in the prepared carton, then place the carton at room temperature, record the temperature changes in the carton after 1 hour and 24 hours, and calculate the temperature rise degree; temperature rise degree = temperature after 24 hours - temperature after 1 hour.

[0066] Waterproof effect: Place the carton under a spray device to simulate rain conditions. After continuous spraying for 60 minutes, check whether there is water seepage inside the carton.

[0067] The cold-insulating and waterproof cartons prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were tested for strength, thermal insulation effect, and waterproof effect. The test results are shown in Table 1.

[0068] Table 1 From the test results in Table 1, it can be seen that the cold-insulating and waterproof cartons prepared in Examples 1 to 3 have high strength, are not easy to fold, have a small degree of temperature rise, and have good heat preservation and waterproof effects.

[0069] In the adhesive of Comparative Example 1, no acrylic copolymer emulsion was added, and the strength of the resulting carton was reduced.

[0070] In Comparative Example 2, no expanded perlite was added to the adhesive, and the strength of the resulting carton was reduced, and the thermal insulation effect was decreased.

[0071] In Comparative Example 3, no glucomannan was added to the adhesive, and the strength of the obtained carton was reduced and the thermal insulation effect was decreased.

[0072] In the adhesive of Comparative Example 4, expanded perlite and glucomannan were not added, and the strength of the obtained carton was reduced, and the thermal insulation effect and waterproof effect were significantly reduced.

[0073] Embodiments 4 to 10 Example 4 The difference between Example 4 and Example 2 is that the thickness of the kt plate layer in Example 4 is 3 mm.

[0074] Example 5 The difference between Example 5 and Example 2 is that the thickness of the kt plate layer in Example 5 is 8 mm.

[0075] Example 6 The difference between Example 6 and Example 2 is that in the adhesive of Example 6, the weight ratio of expanded perlite to glucomannan is 2:1, and the total weight of expanded perlite and glucomannan is 12.2 parts.

[0076] Example 7 The difference between Example 7 and Example 2 is that in the adhesive of Example 7, the weight ratio of expanded perlite to glucomannan is 3:1, and the total weight of expanded perlite and glucomannan is 12.2 parts.

[0077] Example 8 The difference between Example 8 and Example 2 is that in the adhesive of Example 8, the crosslinking agent is tetrabutyl titanate.

[0078] Example 9 The difference between Example 9 and Example 2 is that in the adhesive of Example 9, the preservative is benzisothiazolinone.

[0079] Example 10 The difference between Example 10 and Example 2 is that in the adhesive of Example 10, the flame retardant is urea.

[0080] The cold-insulating and waterproof cartons prepared in Examples 4 to 10 were tested for strength, thermal insulation effect, and waterproof effect. The test results are shown in Table 2.

[0081] Table 2 From the test results in Table 2, it can be seen that the difference between Example 4 and Example 5 and Example 2 is that the thickness of the kt board layer is different. Among them, the cold-insulating and waterproof carton prepared in Example 2 has good thermal insulation effect and saves materials.

[0082] The difference between Example 6 and Example 7 and Example 2 is that the weight ratios of expanded perlite and glucomannan in the adhesive are different. Among them, the cold-insulating and waterproof carton prepared in Example 2 has the highest strength and the best thermal insulation effect.

[0083] The difference between Examples 8 to 10 and Example 2 is that different cross-linking agents, preservatives, and flame retardants are used in the adhesives. The strength, thermal insulation effect, and waterproof effect of the cold-insulating and waterproof cartons prepared in Examples 8 to 10 are similar to those in Example 2.

[0084] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cold-insulating and waterproof carton, characterized in that: It comprises a face paper layer, a KT board layer and a silver card paper layer which are laminated in sequence; the KT board layer and the silver card paper layer are laminated by an adhesive; The raw material composition of the adhesive includes, by weight: 50-70 parts of polyvinyl acetate emulsion, 10-30 parts of acrylate copolymer emulsion, 5-12.5 parts of expanded perlite, 2-5 parts of glucomannan, 1-3 parts of cross-linking agent, 0.1-0.5 parts of preservative, 0.1-0.5 parts of leveling agent, and 1-5 parts of flame retardant; The acrylic copolymer emulsion is prepared from methyl methacrylate, hydroxyethyl methacrylate, an initiator, an emulsifier and water, and the weight ratio of methyl methacrylate, hydroxyethyl methacrylate, initiator, emulsifier and water is 30-50:5-15:0.1-1:1-3:40-50.

2. The cold-insulating and waterproof carton according to claim 1, characterized in that: The surface paper layer is selected from one of kraft paper, white cardboard, laminated paper and coated paper.

3. The cold-insulating and waterproof carton according to claim 1, characterized in that: The kt board layer is made of polystyrene.

4. The cold-insulating and waterproof carton according to claim 1, characterized in that: The thickness of the kt board layer is 3~8mm.

5. The cold-insulating and waterproof carton according to claim 1, characterized in that: The preparation method of the acrylic copolymer emulsion is as follows: the methyl methacrylate, hydroxyethyl methacrylate, half of the emulsifier and half of the water are stirred and mixed to obtain a pre-emulsion; the remaining water and the emulsifier are heated, half of the initiator is added, and the mixture is mixed to obtain a seed emulsion; the pre-emulsion is dripped into the seed emulsion, the remaining initiator is added, the mixture is stirred and kept warm for a reaction of 1 to 2 hours, the mixture is cooled to room temperature, and the mixture is filtered to obtain the acrylic copolymer emulsion.

6. The cold-insulating and waterproof carton according to claim 1, characterized in that: The weight ratio of the expanded perlite to glucomannan is 2-3:

1.

7. The cold-insulating and waterproof carton according to claim 1, characterized in that: The cross-linking agent is selected from at least one of diphenylmethane diisocyanate, bisphenol A type epoxy resin and tetrabutyl titanate.

8. The cold-insulating and waterproof carton according to claim 1, characterized in that: The preservative is selected from at least one of kasone, benzisothiazolinone and potassium sorbate.

9. The cold-insulating and waterproof carton according to claim 1, characterized in that: The flame retardant is selected from at least one of aluminum hydroxide, trimethyl phosphate and urea.

10. A method for preparing a cold-insulating and waterproof paper box according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, mixing the polyvinyl acetate emulsion and the acrylate copolymer emulsion to prepare a premixed solution; S2, sequentially adding the glucomannan, expanded perlite, cross-linking agent, preservative, leveling agent, and flame retardant to the premixed liquid, filtering, and obtaining the adhesive; S3, using an extruder to foam and extrude polystyrene particles to obtain a polystyrene sheet, and hot-pressing two layers of polystyrene sheets to obtain the kt board; S4, spraying the adhesive on one side of the kt board, attaching the silver card paper, drying, and curing; S5, spraying the adhesive on the other side of the kt board, attaching the surface paper, drying, curing, and obtaining a cold-insulating and waterproof board; S6. Use a die-cutting machine to cut the cold-insulating and waterproof board into a desired shape, press out line marks, and finally fold and assemble to obtain a cold-insulating and waterproof carton.

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