Thermal-insulating waterproof high-strength packaging bag and preparation process therefor

Abstract

A thermal-insulating waterproof high-strength packaging bag and a preparation process therefor. The thermal-insulating waterproof high-strength packaging bag is made of composite paper; the composite paper comprises an outer waterproof layer (1), an outer paper layer (2), a first adhesive layer (3), a thermal-insulating buffer layer (4), a second adhesive layer (5), an inner paper layer (6) and an inner waterproof layer (7) which are sequentially arranged; the first adhesive layer (3) and the second adhesive layer (5) are elastic adhesive layers; the preparation process comprises: S1, the first adhesive layer is attached to the thermal-insulating buffer layer and then attached to the outer paper layer, and heat preservation and drying are carried out; S2, the second adhesive layer is attached to the thermal-insulating buffer layer and then attached to the outer paper layer, and heat preservation and drying are carried out; S3, a waterproofing agent is applied to the outer paper layer and the inner paper layer respectively to form the outer waterproof layer and the inner waterproof layer, and drying is carried out to obtain the composite paper; and S4, the composite paper is cut and combined to obtain the thermal-insulating waterproof high-strength packaging bag. The packaging bag has good thermal insulation and waterproofing properties and high strength, is not prone to wrinkling, deformation and damage, provides good protection for the items inside, and has a wide range of application.

Description

A thermal insulation, waterproof and high-strength packaging bag and its preparation process Technical Field

[0001] The present application relates to the field of packaging materials, and more specifically, to a heat-insulating, waterproof, high-strength packaging bag and a preparation process thereof. Background Art

[0002] Packaging bags are used to package items. Different categories of items require packaging bags with different functional requirements.

[0003] In order to improve the environmental friendliness and recyclability of packaging bags, recyclable paper such as kraft paper and corrugated paper is generally used to make packaging bags. At present, common environmentally friendly packaging bags are divided into the following types: the first type is packaging bags made of single-layer kraft paper. This type of packaging bag has the advantage of light weight, but its thermal insulation performance, waterproof performance and compressive strength are relatively low; the second type is packaging bags made of composite corrugated paper. This type of packaging bag has good compressive strength, but its thermal insulation and waterproof performance are average; the third type is packaging bags made of a composite of kraft paper and thermal insulation foam. Although this type of packaging bag has good thermal insulation performance, it is less environmentally friendly, and during transportation, the packaging bag is prone to wrinkles and damage, and its waterproof performance is also low, which reduces the protective performance of the items. Therefore, the current environmentally friendly packaging bags need further improvement.

[0004] Summary of the Invention

[0005] In order to solve the problem that current environmentally friendly packaging bags have low thermal insulation and waterproof properties, are prone to wrinkles and damage during transportation, and have reduced protective performance for items, the present application provides a thermal insulation, waterproof, high-strength packaging bag and its preparation process.

[0006] In a first aspect, the present application provides a heat-insulating, waterproof, high-strength packaging bag, which adopts the following technical solution:

[0007] A heat-insulating, waterproof, and high-strength packaging bag is made of composite paper. The composite paper includes an outer waterproof layer, an outer paper layer, a heat-insulating buffer layer, an inner paper layer, and an inner waterproof layer, which are laminated in sequence. The outer paper layer and the heat-insulating buffer layer are laminated via a first adhesive layer, and the inner paper layer and the heat-insulating buffer layer are laminated via a second adhesive layer. Both the first adhesive layer and the second adhesive layer are elastic adhesive layers.

[0008] By adopting the above technical solution, the packaging bag of the present application is made of a composite paper combination, wherein the inner paper layer and the outer paper layer play a role in improving the bearing capacity of the packaging bag, improving the compressive strength of the packaging bag, making the packaging bag not easy to be damaged, and the heat-insulating buffer layer can prevent the flow of air inside and outside, and play a good heat-insulating and heat-preserving role. At the same time, it also has a good buffering effect, so that the packaging bag is not easy to wrinkle and break when subjected to external pressure, thereby improving the protection of the packaged items. The outer waterproof layer and the inner waterproof layer have a waterproof effect, further blocking moisture and air flow. , thereby improving the waterproof and heat-insulating properties of the packaging bag. The first adhesive layer plays a role in laminating the outer paper layer and the heat-insulating buffer layer, and the second adhesive layer plays a role in laminating the inner paper layer and the heat-insulating buffer layer. The first adhesive layer and the second adhesive layer are set to be elastic adhesive layers, which can cooperate with the heat-insulating buffer layer. When the packaging bag is subjected to external pressure, under the action of the outer paper layer, the heat-insulating buffer layer and the inner paper layer, the external pressure is evenly dispersed and rebounded, reducing the problem of easy wrinkling of the inner and outer paper layers, improving the compressive strength of the packaging bag, and making the packaging bag not easy to be damaged.

[0009] Preferably, the outer waterproof layer has a first buffer structure on one side close to the thermal insulation buffer layer, and the inner waterproof layer has a second buffer structure on one side close to the thermal insulation buffer layer. The first buffer structure and the second buffer structure are the same, and the first buffer structure and the second buffer structure are symmetrically arranged.

[0010] By adopting the above technical solution, the first buffer structure and the second buffer structure are symmetrically arranged, and the structures of the first buffer structure and the second buffer structure are the same. When the packaging bag is subjected to external pressure, the first buffer structure of the outer paper layer and the second buffer structure of the inner paper layer cooperate with the heat-insulating buffer layer, so that the surface of the packaging bag can evenly buffer and rebound the external pressure, further improving the pressure resistance of the packaging bag and reducing the occurrence of wrinkles and damage to the packaging bag.

[0011] Preferably, the first buffer structure is composed of a plurality of protruding portions, and the heights of the protruding portions gradually increase from the middle area to the peripheral edge areas of the outer paper layer.

[0012] By adopting the above technical solution, the horizontal height of the raised portion near the middle area of ​​the outer paper layer is lower, and the horizontal height of the raised portion near the peripheral edge areas of the outer paper layer is higher, so that the thickness of the first adhesive layer between the middle area of ​​the outer paper layer and the thermal insulation buffer layer is thicker, while the thickness of the first adhesive layer between the peripheral edge areas of the outer paper layer and the thermal insulation buffer layer is thinner. Generally, the middle area of ​​a packaging bag is easily squeezed and wrinkled. Therefore, the first adhesive layer and the thermal insulation buffer layer corresponding to the middle area of ​​the outer paper layer play a better cooperative role, and produce a buffering effect on the middle area of ​​the outer paper layer, so that the outer paper layer is dispersed to the surrounding area of ​​the squeezing effect, thereby improving the compressive strength of the packaging bag, and thus making the packaging bag not easy to wrinkle or break.

[0013] Furthermore, the horizontal height of the raised portion in the middle area of ​​the outer paper layer in the present application is 1 / 3-3 / 4 of the height of the outer paper layer, which allows the outer paper layer to have good isolation performance while also having good cushioning elasticity, reducing the occurrence of wrinkles and damage to the packaging bag.

[0014] Preferably, the distribution density of the raised portions gradually decreases from the middle region to the peripheral edge regions of the outer paper layer.

[0015] By adopting the above technical solution, since the middle area of ​​the packaging bag is easily wrinkled by external pressure, the distribution density of the raised parts in the middle area of ​​the outer paper layer is increased, which can evenly disperse the pressure and reduce the occurrence of wrinkles and damage. The first buffer structure cooperates with the first adhesive layer and the heat-insulating buffer layer to evenly disperse and release the pressure. During the assembly process, the edge area of ​​the packaging bag itself needs to be wrinkled. Therefore, the thickness of the surrounding edge areas of the outer paper layer is controlled to be relatively thick, which is easy to shape and can enable the packaging bag to maintain a three-dimensional shape. While having buffering properties, it is not easy to deform.

[0016] Preferably, the heat insulating buffer layer is any one of aerogel cotton, silicone cotton and pearl cotton.

[0017] By adopting the above technical solution, the above heat-insulating buffer layer has good heat-insulating and buffering elasticity, which can improve the heat-insulating and buffering performance of the prepared packaging bag.

[0018] Preferably, the first adhesive layer and the second adhesive layer are both formed by curing an adhesive, and the adhesive is made from the following raw materials in parts by weight:

[0019] By adopting the above technical scheme, in order to further improve the compressive strength and wrinkle resistance of the thermal insulation, waterproof and high-strength packaging bag, and at the same time achieve the bonding stability between multiple layers, the adhesive of the present application is used. The adhesive of the present application uses polyurethane emulsion as the resin main body. The polyurethane emulsion has good adhesion and has good elasticity and toughness after curing. The thickener plays a role in improving the adhesion and can carry the polyurethane emulsion, further improving the adhesion of the adhesive prepared. The wetting agent can produce a good synergistic effect with the thickener, thereby improving the uniform dispersion performance of the adhesive prepared on the surface of the thermal insulation buffer layer, and can be evenly infiltrated and dispersed into the gap between the first buffer structure and the second buffer structure, so that the outer paper layer, the thermal insulation buffer layer and the inner paper layer can be stably bonded. The long-chain alkyl silane coupling agent has a long carbon chain, which can further improve the dispersion stability between the polyurethane emulsion and the thickener and the wetting agent. The adhesive prepared in this way has good bonding stability and elasticity after curing.

[0020] Preferably, the thickener is prepared by the following steps: A1, adding 10-18 parts of starch to 80-120 parts of water by weight, dropwise adding 0.3-0.8 parts of 1-2 mol / L hydrochloric acid aqueous solution, heating to 65-85° C., and stirring for 30-60 minutes to prepare a starch hydrolyzate; A2, adding 0.2-0.5 parts of diethylene glycol, 0.1-0.3 parts of an acrylic acid ester copolymer, and 1-3 parts of magnesium aluminum silicate to the starch hydrolyzate, and stirring uniformly to prepare the thickener.

[0021] By adopting the above technical solution, starch is first hydrolyzed under acidic conditions to make the molecular structure of the starch loose and stable, thereby improving the water absorption and swelling effects of the starch and the load-bearing effect on the polyurethane emulsion. Diethylene glycol, an acrylate copolymer and magnesium aluminum silicate are then added to compound the starch hydrolyzate. Diethylene glycol has a soft long-chain ether group segment and can improve the dispersibility of the acrylate copolymer and magnesium aluminum silicate in the starch hydrolyzate. The addition of the acrylate copolymer and magnesium aluminum silicate can further improve the flowability and adsorption properties of the starch hydrolyzate. The prepared thickener can stably adsorb the polyurethane emulsion and has good bonding stability.

[0022] Preferably, the wetting agent consists of oleylamine polyoxyethylene ether and polyvinyl alcohol, and the weight ratio of the oleylamine polyoxyethylene ether to the polyvinyl alcohol is 1:(0.2-0.6).

[0023] By adopting the above technical solution, the optimal ratio of oleylamine polyoxyethylene ether and polyvinyl alcohol has a better synergistic effect, which can improve the wettability and bonding properties of the prepared adhesive, thereby improving the bonding stability between the outer paper layer, thermal insulation buffer layer and inner paper layer of the packaging bag.

[0024] Preferably, the adhesive is prepared by the following steps:

[0025] B1. Add the wetting agent to water and stir evenly to prepare a mixed solution;

[0026] B2. Add polyurethane emulsion, tackifier and long-chain alkyl silane coupling agent to the mixed liquid, stir evenly to prepare an adhesive.

[0027] By adopting the above technical solution, the wetting agent is first dissolved in water to form a uniformly dispersed mixed liquid. Under the action of the wetting agent, the polyurethane emulsion, tackifier and long-chain alkyl silane coupling agent are uniformly dispersed to prepare an adhesive with a stable system and good bonding performance.

[0028] In a second aspect, the present application provides a process for preparing a heat-insulating, waterproof, high-strength packaging bag, which adopts the following technical solution:

[0029] A preparation process for a heat-insulating, waterproof, high-strength packaging bag comprises the following steps:

[0030] S1. Apply adhesive to one side of the thermal insulation buffer layer to form a first adhesive layer, then adhere the outer paper layer, keep warm, and dry;

[0031] S2. Applying adhesive to the side of the heat-insulating buffer layer away from the outer paper layer to form a second adhesive layer, and then laminating the outer paper layer, keeping warm, and drying;

[0032] S3, applying a waterproofing agent to the inner paper layer to form an inner waterproof layer, applying a waterproofing agent to the outer paper layer to form an outer waterproof layer, and drying to obtain a composite paper;

[0033] S4, cutting and combining the composite paper to prepare a heat-insulating, waterproof and high-strength packaging bag.

[0034] By adopting the above technical solution, a packaging bag is prepared which has good thermal insulation performance, good waterproofness, and is not easy to wrinkle, deform or break.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The thermal insulation, waterproof and high-strength packaging bag of the present application is composed of an outer waterproof layer, an outer paper layer, a first adhesive layer, a thermal insulation buffer layer, a second adhesive layer, an inner paper layer and an inner waterproof layer. It has good thermal insulation and waterproof properties, is not easy to wrinkle, deform and break, has a good protective effect on the packaged items, and has a wide range of applications.

[0037] 2. A first buffer structure is provided on a side of the outer waterproof layer close to the thermal insulation buffer layer, and a second buffer structure is provided on a side of the inner waterproof layer close to the thermal insulation buffer layer. The first buffer structure and the second buffer structure have the same structure. The first buffer structure is composed of a plurality of protrusions. The height of the protrusions gradually increases from the middle area of ​​the outer paper layer to the peripheral edge areas, and the distribution density of the protrusions gradually decreases from the middle area of ​​the outer paper layer to the peripheral edge areas. This makes the thickness of the first adhesive layer between the middle area of ​​the outer paper layer and the thermal insulation buffer layer thicker, while the thickness of the first adhesive layer between the peripheral edge areas of the outer paper layer and the thermal insulation buffer layer thinner. When the packaging bag is subjected to external pressure, the outer paper layer, the first adhesive layer, the thermal insulation buffer layer, the second adhesive layer and the inner paper layer form a matching structure, which can evenly distribute the pressure and reduce the occurrence of wrinkles and damage. The edge areas of the packaging bag need to be wrinkled during the assembly process. Therefore, the thickness of the peripheral edge areas of the outer paper layer is controlled to be relatively thick, which is easy to shape and can enable the packaging bag to maintain a three-dimensional shape. While having cushioning properties, it is not easy to deform.

[0038] 3. An adhesive is prepared using polyurethane emulsion, a tackifier, a wetting agent, a long-chain alkyl silane coupling agent, and water. The tackifier is composed of starch, diethylene glycol, an acrylate copolymer, and magnesium aluminum silicate, and the wetting agent is composed of oleylamine polyoxyethylene ether and polyvinyl alcohol. The tackifier and the wetting agent produce a good synergistic effect and stably adsorb the polyurethane emulsion. The adhesive prepared in this way has good bonding stability. The first adhesive layer and the second adhesive layer formed after curing have good elasticity, which can further improve the strength and cushioning performance of the packaging bag. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of the interlayer structure of a composite paper for a heat-insulating, waterproof, high-strength packaging bag according to Example 1 of the present application;

[0040] FIG2 is a schematic diagram of the interlayer structure of a composite paper for a heat-insulating, waterproof, high-strength packaging bag according to Example 4 of the present application;

[0041] FIG3 is a schematic diagram of the interlayer structure of the composite paper of a heat-insulating, waterproof, and high-strength packaging bag according to Example 5 of the present application.

[0042] Description of the drawings: 1. Outer waterproof layer; 2. Outer paper layer; 21. First buffer structure; 3. First adhesive layer; 4. Heat insulation buffer layer; 5. Second adhesive layer; 6. Inner paper layer; 61. Second buffer structure; 7. Inner waterproof layer. DETAILED DESCRIPTION

[0043] The present application is further described in detail below with reference to Figures 1-3 and embodiments.

[0044] The following are the sources and specifications of some raw materials in this application. The raw materials in the preparation examples and examples of this application can be obtained commercially. The raw materials used in this application include but are not limited to the specific models and manufacturers disclosed below. Raw materials with the same specifications and properties can be used:

[0045] 1. Starch: corn starch, industrial grade, content 99%;

[0046] 2. Acrylate copolymer: Carbomer U21, brand Lubrizol;

[0047] 3. Magnesium aluminum silicate: 325 mesh, content 99%, pH = 6.3, whiteness 90%;

[0048] 4. Kaolin: calcined kaolin, 325 mesh, density 2.54-2.60g / cm 3 ;

[0049] 5. Polyurethane emulsion: Bayer brand, content 40-50%, viscosity 700-1500 mPa·s at 25 degrees Celsius, pH = 7-9, density 1.04-1.09 g / cm 3 ;

[0050] 6. Oleylamine polyoxyethylene ether: oleylamine polyoxyethylene (2) ether;

[0051] 7. Polyvinyl alcohol: molecular weight 25,000-35,000 Daltons, content 99%, pH = 4.5-6.5.

[0052] Preparation Example of Thickener

[0053] Preparation Example 1

[0054] Preparation Example 1 discloses a tackifier, which is prepared by the following steps:

[0055] A1. Add 1 kg of starch to 8 kg of water, add dropwise 0.03 kg of 1 mol / L hydrochloric acid solution, heat to 65°C, and stir for 30 min to obtain starch hydrolysate;

[0056] A2. Add 0.02 kg of diethylene glycol, 0.01 kg of carbomer U21 and 0.1 kg of magnesium aluminum silicate to the starch hydrolyzate, and stir at a stirring rate of 300 r / min for 20 min to prepare a thickener.

[0057] Preparation Example 2-3

[0058] The difference between Preparation Example 2-3 and Preparation Example 1 is that the amount of raw materials used and the preparation conditions are different. Please refer to Table 1 below for details.

[0059] Table 1 Raw material dosage and preparation conditions of Preparation Examples 1-3

[0060] Preparation Comparative Example 1

[0061] The difference between Preparation Comparative Example 1 and Preparation Example 1 is that an equal amount of diethylene glycol is replaced by polyethylene glycol 400, and the rest is the same as Preparation Example 1.

[0062] Preparation Comparative Example 2

[0063] The difference between Preparation Comparative Example 2 and Preparation Example 1 is that an equal amount of magnesium aluminum silicate is replaced by kaolin, and the rest is the same as Preparation Example 1.

[0064] Preparation Comparative Example 3

[0065] The difference between Preparation Example 3 and Preparation Example 1 is that an equal amount of Carbomer U21 is replaced by hydroxyethyl methylcellulose, and the rest is the same as Preparation Example 1.

[0066] Preparation Comparative Example 4

[0067] The difference between Preparation Example 4 and Preparation Example 1 is that an equal amount of magnesium aluminum silicate is replaced by carbomer U21, and the rest is the same as Preparation Example 1.

[0068] Adhesive Preparation Example

[0069] Preparation Example 4

[0070] Preparation Example 4 discloses an adhesive prepared by the following steps:

[0071] B1. Add 0.4 kg of polyvinyl alcohol as a wetting agent to 2 kg of water, stir at a temperature of 60° C. and a stirring rate of 300 r / min for 20 min, and stir until uniform to obtain a mixed solution;

[0072] B2. Add 4 kg of polyurethane emulsion, 1.2 kg of hydroxyethyl methyl cellulose as a tackifier, and 0.05 kg of dodecyltrimethoxysilane as a silane coupling agent to the mixed solution, stir at a stirring rate of 500 r / min for 30 min, and stir until uniform to obtain an adhesive.

[0073] Preparation Example 5-6

[0074] The difference between Preparation Example 5-6 and Preparation Example 1 is that the amount of raw materials used and the preparation conditions are different. Please refer to Table 2 below for details.

[0075] Table 2 Raw material dosage and preparation conditions of Preparation Examples 4-6

[0076] Preparation Example 7-13

[0077] The difference between Preparation Examples 7-13 and Preparation Example 4 is that the sources of the tackifiers are different. For details, see Table 3 below.

[0078] Table 3 Sources of tackifiers for Preparation Examples 7-13

[0079] Preparation Example 14

[0080] The difference between Preparation Example 14 and Preparation Example 7 is that the wetting agent is different. The wetting agent in Preparation Example 14 is composed of oleylamine polyoxyethylene ether and polyvinyl alcohol. The amount of oleylamine polyoxyethylene ether is 0.33 kg, and the amount of polyvinyl alcohol is 0.07 kg. The rest is the same as Preparation Example 7.

[0081] Preparation Example 15

[0082] The difference between Preparation Example 15 and Preparation Example 7 is that the wetting agent in Preparation Example 15 consists of oleylamine polyoxyethylene ether and polyvinyl alcohol, the amount of oleylamine polyoxyethylene ether used is 0.25 kg, and the amount of polyvinyl alcohol used is 0.15 kg. The rest is the same as Preparation Example 7.

[0083] Preparation Comparative Example 5

[0084] The difference between Preparation Comparative Example 5 and Preparation Example 14 is that the long-chain alkylsilane coupling agent is replaced by an equal amount of methyltriethoxysilane coupling agent, and the rest is the same as Preparation Example 14.

[0085] Example

[0086] Example 1

[0087] Example 1 discloses a thermal insulation, waterproof, high-strength packaging bag, which is made by cutting and assembling composite paper. Referring to Figure 1, the composite paper includes an outer waterproof layer, an outer paper layer, a thermal insulation buffer layer, an inner paper layer and an inner waterproof layer, which are sequentially bonded. The outer paper layer and the thermal insulation buffer layer are bonded by a first adhesive layer, and the inner paper layer and the thermal insulation buffer layer are bonded by a second adhesive layer. The outer waterproof layer and the inner waterproof layer are PE waterproof layers. The outer paper layer and the inner paper layer are both kraft paper. The thickness of the kraft paper is 0.1-1mm. The thickness of the kraft paper in this embodiment is 0.5mm. The thermal insulation buffer layer is aerogel cotton, silicone cotton, pearl cotton, etc. The thermal insulation buffer layer in this embodiment is silicone cotton. The thickness of the thermal insulation buffer layer is 0.1-2mm. The thickness of the thermal insulation buffer layer in this embodiment is 1mm. The first adhesive layer and the second adhesive layer are both elastic adhesive layers, which are made by curing the adhesive.

[0088] The heat-insulating, waterproof and high-strength packaging bag is prepared by the following steps:

[0089] S1. Apply commercially available adhesive to one side of the thermal insulation buffer layer, controlling the coating amount to 30g / m 2 , forming the first adhesive layer, and then laminating the outer paper layer, keeping it warm at 40°C for 20 minutes, and then drying it at 100°C;

[0090] S2. Apply commercially available adhesive to the side of the thermal insulation buffer layer away from the outer paper layer, and control the coating amount to 30g / m 2 , forming the second adhesive layer, and then laminating the outer paper layer, keeping it warm at 40°C for 20 minutes, and then drying it at 100°C;

[0091] S3, melt the PE material to form a PE waterproofing agent, cast it on the inner paper layer to form an inner waterproof layer, and apply the PE waterproofing agent to the outer paper layer to form an outer waterproof layer. The coating amount of the PE waterproofing agent is controlled to be 10g / m 2 , drying at a temperature of 20° C. for 30 minutes to obtain composite paper;

[0092] S4, cutting and combining the composite paper to make a heat-insulating, waterproof and high-strength packaging bag,

[0093] Among them, commercially available adhesives: water-based polyurethane adhesive, brand: Dibang Nano Technology, viscosity at 25 degrees Celsius 100-450cps, solid content 40%, pH = 7.0-8.5;

[0094] PE material: low-density polyethylene, brand: Dow Chemical, model 4203;

[0095] Aerogel cotton: thermal conductivity 0.02W / (m·K), compressive strength 18MPa, density 180-220kg / m 3 ;

[0096] Silicone cotton: thermal conductivity 0.02W / (m·K), 120-160kg / m3;

[0097] Pearl cotton: EPE foam, thermal conductivity 0.02W / (m·K), 28-35kg / m3.

[0098] Example 2-3

[0099] The difference between Example 2-3 and Example 1 is that the preparation process parameters are also different and the sources of the adhesive are different. For details, see Table 4 below.

[0100] Table 4 Preparation process parameters and adhesive sources of Examples 1-3

[0101] Example 4

[0102] The difference between Example 4 and Example 1 is that, referring to Figure 2, the structure of the composite paper is different, the outer waterproof layer has a first buffer structure on one side close to the thermal insulation buffer layer, and the inner waterproof layer has a second buffer structure on one side close to the thermal insulation buffer layer. The first buffer structure and the second buffer structure are symmetrically arranged, wherein the first buffer structure is composed of a plurality of protruding portions, and the horizontal height of the protruding portions gradually increases from the middle area of ​​the outer paper layer to the surrounding edge areas. The first buffer structure and the second buffer structure are the same, the distribution density of the protruding portions is the same, and the rest is the same as Example 1.

[0103] Example 5

[0104] The difference between Example 5 and Example 4 is that, referring to Figure 3, on the basis of Example 4, the distribution density of the raised parts gradually decreases from the middle area of ​​the outer paper layer to the surrounding edge areas, the distribution density of the raised parts of the inner paper layer is the same as that of the outer paper layer, and the rest is the same as Example 4.

[0105] Examples 6-18

[0106] The difference between Examples 6-18 and Example 5 is that the sources of the adhesive are different, see Table 5 below for details.

[0107] Table 5 Sources of adhesives for Examples 6-18

[0108] Performance testing

[0109] The following performance tests were conducted on the thermal insulation, waterproof, high-strength packaging bags prepared in Examples 1-18:

[0110] (1) Folding endurance test

[0111] According to the test method in GB / T 13024-2003, test the folding endurance (unit: times) of thermal insulation, waterproof and high-strength packaging bags, and test and record the test results;

[0112] (2) Burst strength test

[0113] According to the test method in GB / T 13024-2003, the burst resistance index of thermal insulation and waterproof high-strength packaging bags (unit: kPa·m 2 / g), test and record the test results;

[0114] (3) Peel strength test

[0115] Refer to the test method in GB / T 34444-2017 to test the peel strength (unit: N / cm) of thermal insulation and waterproof high-strength packaging bags, and test and record the test results;

[0116] The following are the performance test data of the thermal insulation, waterproof and high-strength packaging bags prepared in Examples 1-18. Please refer to Table 6 below for details.

[0117] Table 6 Performance test data of thermal insulation, waterproof and high strength packaging bags of Examples 1-18

[0118] In combination with Examples 1-5 and Table 6, it can be seen that the first buffer structure of the outer paper layer and the second buffer structure of the inner paper layer of the present application are combined with the heat-insulating buffer layer to improve the strength of the prepared packaging bag, and the interlayer bonding is more stable and not easy to wrinkle and deform. The raised portions in Example 2 are evenly distributed, while the distribution density of the raised portions in Example 3 decreases from the middle area to the surrounding edge areas. It can be seen from the data that the peel strength in Example 2 is slightly greater than the peel strength in Example 3. It may be that the use of evenly distributed raised portions is more conducive to bonding, but the folding resistance and bursting resistance index in Example 2 are significantly greater than those in Example 3, indicating that the different distribution densities of the raised portions can improve the strength of the prepared packaging bag. Overall, the packaging bag in Example 3 has better performance.

[0119] From Examples 1-5 and 6-15 and Table 6, it can be seen that the use of the thickener of the present application can further improve the bonding stability of the prepared adhesive and improve the strength of the prepared packaging bag. In Examples 12-15, starch, diethylene glycol, carbomer U21 and magnesium aluminum silicate were not used for compounding, and the strength of the prepared packaging bag was reduced, and the folding resistance was also reduced, indicating that starch, diethylene glycol, carbomer U21 and magnesium aluminum silicate can produce a good synergistic effect, and the strength of the prepared packaging bag is better.

[0120] From Examples 9-11 and 16-17 and Table 6, it can be seen that the compounding of oleylamine polyoxyethylene ether and polyvinyl alcohol in the preferred ratio of the present application can produce a good synergistic effect with the tackifier, further improving the interlayer bonding stability of the packaging bag and improving the strength of the prepared packaging bag.

[0121] It can be seen from Examples 16-17 and Example 18 and Table 6 that the use of a long-chain alkyl silane coupling agent can better improve the strength of the prepared packaging bag.

[0122] In summary, in this application, a composite paper is formed by bonding an outer waterproof layer, an outer paper layer, a first adhesive layer, a heat insulating buffer layer, a second adhesive layer, an inner paper layer and an inner waterproof layer. The packaging bag made of this composite paper has good thermal insulation performance, waterproof performance and strength; at the same time, the adhesive of this application is used to cure to form the first adhesive layer and the second adhesive layer, which have good elasticity and adhesion, and are not easy to wrinkle and deform after being subjected to external pressure, thereby further improving the buffering performance and strength of the prepared packaging bag.

[0123] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A heat-insulating, waterproof and high-strength packaging bag, characterized in that, It is made of composite paper, and the composite paper includes an outer waterproof layer, an outer paper layer, a heat insulation and buffer layer, an inner paper layer and an inner waterproof layer which are sequentially laminated. The outer paper layer and the heat insulation and buffer layer are laminated through a first adhesive layer, the inner paper layer and the heat insulation and buffer layer are laminated through a second adhesive layer, and both the first adhesive layer and the second adhesive layer are elastic adhesive layers.

2. The heat-insulating, waterproof and high-strength packaging bag according to claim 1, wherein, One side of the outer waterproof layer close to the heat insulation and buffer layer has a first buffer structure, one side of the inner waterproof layer close to the heat insulation and buffer layer has a second buffer structure, the first buffer structure and the second buffer structure are the same, and the first buffer structure and the second buffer structure are symmetrically arranged.

3. The heat-insulating, waterproof and high-strength packaging bag according to claim 2, characterized in that, The first buffer structure is composed of several convex parts, and the horizontal height of the convex parts gradually increases from the central area to the peripheral edge area of the outer paper layer.

4. The heat-insulating, waterproof and high-strength packaging bag according to claim 3, wherein, The distribution density of the convex parts gradually decreases from the central area to the peripheral edge area of the outer paper layer.

5. The heat-insulating, waterproof and high-strength packaging bag according to claim 1, characterized in that, The heat insulation and buffer layer is any one of aerogel cotton, silicone cotton, and EPE.

6. The heat-insulating, waterproof and high-strength packaging bag according to claim 1, wherein, Both the first adhesive layer and the second adhesive layer are formed by curing an adhesive, and the adhesive is prepared from the following raw materials in parts by weight: 40-60 parts of polyurethane emulsion, 12-22 parts of tackifier, 4-8 parts of wetting agent, 0.5-2 parts of long-chain alkyl silane coupling agent, and 20-30 parts of water.

7. The heat-insulating, waterproof and high-strength packaging bag according to claim 6, characterized in that The tackifier is prepared by the following steps: A1. Add 10-18 parts of starch to 80-120 parts of water according to parts by weight, drop 0.3-0.8 parts of 1-2 mol / L hydrochloric acid aqueous solution, heat up to 65-85 °C, and stir for 30-60 min to obtain a starch hydrolyzate. A2. Add 0.2-0.5 parts of diethylene glycol, 0.1-0.3 parts of acrylate copolymer, and 1-3 parts of magnesium aluminum silicate to the starch hydrolyzate, and stir evenly to obtain a tackifier.

8. A heat-insulating, waterproof and high-strength packaging bag according to claim 6, characterized in that, The wetting agent is composed of oleylamine polyoxyethylene ether and polyvinyl alcohol, and the weight ratio of oleylamine polyoxyethylene ether to polyvinyl alcohol is 1:(0.2-0.6).

9. A heat-insulating, waterproof and high-strength packaging bag according to any one of claims 6-8, characterized in that, The adhesive is prepared by the following steps: B1. Add the wetting agent to water and stir evenly to obtain a mixed solution. B2. Add polyurethane emulsion, tackifier, and long-chain alkyl silane coupling agent to the mixed solution and stir evenly to obtain an adhesive.

10. A preparation process of a heat-insulating, waterproof and high-strength packaging bag as described in any one of claims 6-9, characterized in that, It includes the following steps: S1. Coat the adhesive on one side of the heat insulation and buffer layer to form a first adhesive layer, laminate the outer paper layer, keep warm, and dry. S2. Coat the adhesive on the side of the heat insulation and buffer layer away from the outer paper layer to form a second adhesive layer, then laminate the outer paper layer, keep warm, and dry. S3. Coat a waterproof agent on the inner paper layer to form an inner waterproof layer, coat a waterproof agent on the outer paper layer to form an outer waterproof layer, and dry to obtain composite paper. S4. Cut and combine the composite paper to obtain a heat-insulating, waterproof and high-strength packaging bag. S4. Cut and combine the composite paper to obtain a heat-insulating, waterproof and high-strength packaging bag.

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