Waterproof sealing flexible hot melt adhesive and preparation method thereof

Abstract

The invention discloses a waterproof sealing flexible hot melt adhesive and a preparation method thereof, and relates to the field of hot melt adhesives. The waterproof sealing flexible hot melt adhesive is prepared from 65 to 70 parts of EVA (Ethylene Vinyl Acetate) resin, 20 to 22 parts of POE (Polyolefin Elastomer), 5.5 to 6.5 parts of maleic anhydride grafted POE, 4.2 to 4.8 parts of SIS (Styrene Isoprene Styrene) block copolymer, 1.2 to 1.8 parts of maleic anhydride grafted SIS block copolymer, 15 to 20 parts of tackifier, 4 to 6 parts of viscosity modifier and 1 to 1.5 parts of antioxidant. According to the hot melt adhesive, the EVA resin, the POE polyolefin elastomer and the SIS block copolymer are matched, and the compatibility of the EVA resin, the POE polyolefin elastomer and the SIS block copolymer is improved through the maleic anhydride grafted POE polyolefin elastomer and the maleic anhydride grafted SIS block copolymer, so that the hot melt adhesive with a good bonding effect on a film-coated paper box and a good low-temperature-resistant effect can be obtained; and the bonding durability of the film-coated paper box in a humid environment or a low-temperature environment can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of hot melt adhesives, and in particular to a waterproof and sealing flexible hot melt adhesive and a preparation method thereof. Background Art

[0002] Hot melt adhesive is a widely used adhesive in the packaging industry. It is favored for its fast bonding, easy operation, high cost-effectiveness and environmental protection. In the application of packaging boxes, hot melt adhesive is mainly used for carton sealing, gift box bonding, food packaging bonding and other occasions.

[0003] As a common packaging material, paper boxes are widely used in daily life. As people's requirements for packaging quality continue to increase, the waterproof performance of paper boxes has become an important indicator to measure their quality. Waterproof paper boxes can not only effectively protect the contents from the influence of humid environments, but also ensure that the paper boxes have good load-bearing capacity and aesthetics under various environmental conditions, which is of great significance to improving the market competitiveness of packaging products.

[0004] At present, in order to improve the waterproof performance of paper boxes, relevant technologies usually perform lamination on the surface of paper boxes. However, after the sticky part of the paper box is laminated (PE film or PP film), it is difficult for hot melt adhesive to penetrate into the cardboard, resulting in the laminated paper box being difficult to stick firmly and prone to debonding problems, especially in low temperature environments. Summary of the invention

[0005] In order to improve the problem of poor bonding performance of hot melt adhesive to coated paper boxes in the related art, the present application provides a waterproof and sealing flexible hot melt adhesive and a preparation method thereof.

[0006] In the first aspect, the present application provides a waterproof and sealing flexible hot melt adhesive adopting the following technical solution: A waterproof and sealing flexible hot melt adhesive comprises 65-70 parts by weight of EVA resin, 20-22 parts by weight of POE polyolefin elastomer, 5.5-6.5 parts by weight of maleic anhydride grafted POE polyolefin elastomer, 4.2-4.8 parts by weight of SIS block copolymer, 1.2-1.8 parts by weight of maleic anhydride grafted SIS block copolymer, 15-20 parts by weight of tackifier, 4-6 parts by weight of viscosity regulator and 1-1.5 parts by weight of antioxidant.

[0007] EVA resin can provide good bonding while reducing costs. The cost of POE polyolefin elastomer is relatively high, but POE polyolefin elastomer has better low-temperature flexibility and bonding effect on coated paper boxes. SIS block copolymer can further improve the low-temperature resistance of hot melt adhesive and the adhesion performance to coated paper boxes. In this application, the combination of EVA resin, POE polyolefin elastomer, and SIS block copolymer in the above ratio is conducive to obtaining a hot melt adhesive with good bonding effect and good low-temperature resistance to coated paper boxes. The hot melt adhesive has high bonding strength to the coated paper boxes, which can improve the bonding seal. In addition, EVA resin, POE polyolefin elastomer and SIS block copolymer themselves have good waterproof properties, which can effectively resist the degumming problem caused by moisture penetrating the bonding interface. Therefore, the hot melt adhesive of this application can effectively improve the bonding durability of coated paper boxes in humid or low-temperature environments. The introduction of maleic anhydride grafted POE polyolefin elastomer and maleic anhydride grafted SIS block copolymer is conducive to improving the compatibility of EVA resin, POE polyolefin elastomer and SIS block copolymer, and has a promoting effect on effectively improving the bonding durability of coated paper boxes in humid environments or low-temperature environments. The introduction of tackifiers is conducive to further improving the adhesion of hot melt adhesive to coated paper boxes, and is also conducive to further improving the bonding durability of coated paper boxes. The addition of viscosity regulators is conducive to the uniform fusion of various components, and the addition of antioxidants can prevent the thermal degradation of various raw material components during the processing process, and is also conducive to improving the bonding durability of coated paper boxes. That is, the acquisition of hot melt adhesives in this application that have good bonding effect and good low-temperature flexibility for coated paper boxes and can maintain bonding durability in humid environments or low-temperature environments depends on the coordination between the above-mentioned raw materials.

[0008] In some specific embodiments, the waterproof and sealing flexible hot melt adhesive further includes 1.8-2.4 parts by weight of vinyl silane coupling agent modified silica.

[0009] In the present application, adding an appropriate amount of vinyl silane coupling agent modified silica is beneficial to further improve the waterproofness of the hot melt adhesive and the bonding strength to the coated paper box, while not significantly affecting the low-temperature flexibility of the hot melt adhesive.

[0010] In some specific embodiments, the method for preparing the vinyl silane coupling agent modified silica comprises the following steps: S1, using plasma to etch the surface of silicon dioxide to obtain pre-modified silicon dioxide; S2. Add the pre-modified silica to the ethanol solution of the vinyl silane coupling agent, raise the temperature to 55-60° C., stir for reaction, centrifuge, wash and dry to obtain the vinyl silane coupling agent modified silica.

[0011] In the preparation of silica modified with a vinyl silane coupling agent, the present application first uses plasma to perform surface treatment on silica to obtain pre-modified silica, and then uses a vinyl silane coupling agent to modify the pre-modified silica. After adding the step of surface modification of silica with plasma, the silica modified with a vinyl silane coupling agent is prone to form an irregular surface, and the introduction of the silica modified with a vinyl silane coupling agent can further improve the bonding performance of the hot melt adhesive to the coated paper box.

[0012] In some specific embodiments, in step S1, the particle size of the silicon dioxide is in the range of 10-20 μm.

[0013] In some specific embodiments, in step S1, the etching gas is a combination of CH3F and O2, the gas flow rate of CH3F is 10-15mL / min, the gas flow rate of O2 is 50-55mL / min, the pressure in the etching chamber is 25-35Pa, the RF power is 120-130W, and the etching time is 20-30s.

[0014] In some specific embodiments, the vinyl silane coupling agent is at least one of vinyl trimethoxy silane and vinyl triethoxy silane.

[0015] In some specific embodiments, the vinyl acetate content of the EVA resin is 25-30%.

[0016] In some specific embodiments, the melt index of the POE polyolefin elastomer is 5-10 g / 10 min (190° C., 2.16 kg), and the grafting rate of maleic anhydride in the maleic anhydride grafted POE polyolefin elastomer is 1.2-1.5%.

[0017] In some specific embodiments, the melt index of the SIS block copolymer is 9-15 g / 10 min (200° C., 5 kg), and the grafting rate of maleic anhydride in the maleic anhydride grafted SIS block copolymer is 0.8-1.2%.

[0018] In some specific embodiments, the tackifier is petroleum resin, the viscosity modifier is at least one of paraffin wax, polyethylene wax, and polypropylene wax, and the antioxidant is at least one of antioxidant 1010 and antioxidant 1076.

[0019] In the second aspect, the present application provides a method for preparing a waterproof and sealing flexible hot melt adhesive using the following technical solution: A method for preparing a waterproof and sealing flexible hot melt adhesive, comprising the following steps: Melting the viscosity modifier and the antioxidant uniformly according to the proportion to obtain a first mixture; Adding EVA resin, POE polyolefin elastomer, maleic anhydride grafted POE polyolefin elastomer, SIS block copolymer and maleic anhydride grafted SIS block copolymer to the first mixture, melting them uniformly, to obtain a second mixture; A tackifier is added to the second mixture and melted evenly to obtain a waterproof and sealing flexible hot melt adhesive.

[0020] The present application adopts the above method to prepare waterproof and sealing flexible hot melt adhesive, which is conducive to the uniform mixing of various components, and is conducive to obtaining a hot melt adhesive with good bonding effect on coated paper boxes and good low-temperature flexibility, and can maintain bonding durability in humid or low-temperature environments.

[0021] In summary, this application at least includes the following beneficial technical effects: (1) The present application obtains a hot melt adhesive having good bonding effect on coated paper boxes and good low-temperature resistance by combining the EVA resin, POE polyolefin elastomer and SIS block copolymer in the above-mentioned proportions, and improving the compatibility of the three by grafting POE polyolefin elastomer with maleic anhydride and grafting SIS block copolymer with maleic anhydride, thereby effectively improving the bonding durability of the coated paper boxes in humid or low-temperature environments.

[0022] (2) In the present application, adding an appropriate amount of vinyl silane coupling agent modified silica is beneficial to further improve the waterproofness of the hot melt adhesive and the bonding strength to the coated paper box, while not significantly affecting the low-temperature flexibility of the hot melt adhesive.

[0023] (3) When preparing silica modified with a vinyl silane coupling agent, firstly, the silica is surface treated with plasma to obtain pre-modified silica, and then the pre-modified silica is modified with a vinyl silane coupling agent. After adding the step of surface modification of silica with plasma, the silica modified with a vinyl silane coupling agent is easy to form an irregular surface. The introduction of the silica modified with a vinyl silane coupling agent can further improve the bonding performance of the hot melt adhesive to the coated paper box. DETAILED DESCRIPTION

[0024] The following is a further explanation based on specific experiments. Example

[0025] [Example 1] A waterproof and sealing flexible hot melt adhesive, including 65kg EVA resin (Dow Chemical 220W), 22kg POE polyolefin elastomer (Dow Chemical 7447EL), 5.5kg maleic anhydride grafted POE polyolefin elastomer (obtained by grafting maleic anhydride on POE polyolefin elastomer 7447EL, and the grafting rate of maleic anhydride is 1.25%), 4.2kg SIS block copolymer (TSR 4111ND), 1.2kg maleic anhydride grafted SIS block copolymer (obtained by grafting maleic anhydride on SIS block copolymer 4111ND, and the grafting rate of maleic anhydride is 1.0%), 15kg C5 hydrogenated petroleum resin (Hengtai Petrochemical H5-1100), 4kg polyethylene wax (Clariant 3620) and 1kg antioxidant 1010.

[0026] In this embodiment, the preparation method of the waterproof and sealing flexible hot melt adhesive includes the following steps: The polyethylene wax and the antioxidant 1010 are uniformly melted at 160-165° C. according to the proportion to obtain a first mixture; After cooling the first mixture to 145-150° C., adding EVA resin, POE polyolefin elastomer, maleic anhydride grafted POE polyolefin elastomer, SIS block copolymer and maleic anhydride grafted SIS block copolymer, and melting them uniformly to obtain a second mixture; The temperature of the second mixture is maintained at 145-150° C., C5 hydrogenated petroleum resin is added to the second mixture, and the mixture is melted evenly to obtain a waterproof and sealing flexible hot melt adhesive.

[0027] [Example 2] A waterproof and sealing flexible hot melt adhesive, comprising 68kg EVA resin (Dow Chemical 220W), 21kg POE polyolefin elastomer (Dow Chemical 7447EL), 6kg maleic anhydride grafted POE polyolefin elastomer (obtained by grafting maleic anhydride on POE polyolefin elastomer 7447EL, with a grafting rate of maleic anhydride of 1.25%), 4.4kg SIS block copolymer (TSR 4111ND), 1.4kg maleic anhydride grafted SIS block copolymer (obtained by grafting maleic anhydride on SIS block copolymer 4111ND, with a grafting rate of maleic anhydride of 1.0%), 20kg C9 hydrogenated petroleum resin (Hengtai Petrochemical H9-1110), 6kg polypropylene wax (Clariant 6050m) and 1.5kg antioxidant 1076.

[0028] In this embodiment, the preparation method of the waterproof and sealing flexible hot melt adhesive includes the following steps: The polypropylene wax and the antioxidant 1076 are uniformly melted at 160-165° C. according to the proportion to obtain a first mixture; After cooling the first mixture to 145-150° C., adding EVA resin, POE polyolefin elastomer, maleic anhydride grafted POE polyolefin elastomer, SIS block copolymer and maleic anhydride grafted SIS block copolymer, and melting them uniformly to obtain a second mixture; The temperature of the second mixture is maintained at 145-150° C., C9 hydrogenated petroleum resin is added to the second mixture, and melted evenly to obtain a waterproof and sealing flexible hot melt adhesive.

[0029] [Example 3] A waterproof and sealing flexible hot melt adhesive, comprising 70kg EVA resin (Dow Chemical 220W), 20kg POE polyolefin elastomer (Dow Chemical 7447EL), 6.5kg maleic anhydride grafted POE polyolefin elastomer (obtained by grafting maleic anhydride on POE polyolefin elastomer 7447EL, with a grafting rate of maleic anhydride of 1.25%), 4.8kg SIS block copolymer (TSR 4111ND), 1.8kg maleic anhydride grafted SIS block copolymer (obtained by grafting maleic anhydride on SIS block copolymer 4111ND, with a grafting rate of maleic anhydride of 1.0%), 20kg C9 hydrogenated petroleum resin (Hengtai Petrochemical H9-1110), 6kg polypropylene wax (Clariant 6050m) and 1.5kg antioxidant 1076.

[0030] In this embodiment, the preparation method of the waterproof and sealing flexible hot melt adhesive includes the following steps: The polypropylene wax and the antioxidant 1076 are uniformly melted at 160-165° C. according to the proportion to obtain a first mixture; After cooling the first mixture to 145-150° C., adding EVA resin, POE polyolefin elastomer, maleic anhydride grafted POE polyolefin elastomer, SIS block copolymer and maleic anhydride grafted SIS block copolymer, and melting them uniformly to obtain a second mixture; The temperature of the second mixture is maintained at 145-150° C., C9 hydrogenated petroleum resin is added to the second mixture, and melted evenly to obtain a waterproof and sealing flexible hot melt adhesive.

[0031] [Example 4] A waterproof and sealing flexible hot melt adhesive, which differs from [Example 1] in that: 2.0 kg of vinyl silane coupling agent modified silica is also added.

[0032] In this embodiment, the preparation method of vinyl silane coupling agent modified silica comprises the following steps: 1 kg of silica with a particle size of 10-20 μm was added to 10 kg of ethanol solution of vinyl trimethoxysilane (the mass concentration of vinyl trimethoxysilane was 1%), the temperature was raised to 60° C., the mixture was stirred for reaction, and then centrifuged, washed, and dried to obtain silica modified with a vinyl silane coupling agent.

[0033] [Example 5] A waterproof and sealing flexible hot melt adhesive, which differs from [Example 1] in that: 2.0 kg of vinyl silane coupling agent modified silica is also added.

[0034] In this embodiment, the preparation method of vinyl silane coupling agent modified silica comprises the following steps: S1. Surface etching of silicon dioxide was performed by plasma, the etching gas was a combination of CH3F and O2, the gas flow rate of CH3F was 12 mL / min, the gas flow rate of O2 was 50 mL / min, the pressure in the etching chamber was 30 Pa, the radio frequency power was 125 W, and the etching time was 25 s to obtain pre-modified silicon dioxide; S2. Add 1 kg of pre-modified silica to 10 kg of ethanol solution of vinyltrimethoxysilane (the mass concentration of vinyltrimethoxysilane is 1%), heat to 60° C., stir for reaction, centrifuge, wash and dry to obtain silica modified with vinylsilane coupling agent.

[0035] Comparative Example [Comparative Example 1] A hot melt adhesive, which differs from [Example 1] in that: The maleic anhydride grafted POE polyolefin elastomer is replaced by an equal amount of POE polyolefin elastomer.

[0036] [Comparative Example 2] A hot melt adhesive, which differs from [Example 1] in that: The maleic anhydride grafted SIS block copolymer was replaced by an equal amount of SIS block copolymer.

[0037] [Comparative Example 3] A hot melt adhesive, which differs from [Example 1] in that the distribution ratios of each group are different.

[0038] In this comparative example, the hot melt adhesive includes 85kg EVA resin (Dow Chemical 220W), 12kg POE polyolefin elastomer (Dow Chemical 7447EL), 1.5kg maleic anhydride grafted POE polyolefin elastomer (obtained by grafting maleic anhydride on POE polyolefin elastomer 7447EL, and the grafting rate of maleic anhydride is 1.25%), 1.2kg SIS block copolymer (TSR 4111ND), 0.8kg maleic anhydride grafted SIS block copolymer (obtained by grafting maleic anhydride on SIS block copolymer 4111ND, and the grafting rate of maleic anhydride is 1.0%), 15kg C5 hydrogenated petroleum resin (Hengtai Petrochemical H5-1100), 4kg polyethylene wax (Clariant 3620) and 1kg antioxidant 1010.

[0039] Performance testing 1. Adhesion performance test: Take 8 groups of identical PE-coated cartons, 10 in each group. Apply the 8 kinds of hot melt adhesives in the embodiments and comparative examples to the sealing interfaces of the 8 groups of PE-coated cartons, respectively, with a coating amount of 5g / carton, and then place them in an environment with a temperature of 25°C and a humidity of 70% for 24 hours, and then continue to place them for 180 days, and then test the average broken area of ​​the cartons when peeling off the sealing interface of the cartons. Among them, the larger the broken area, the better the bonding performance of the hot melt adhesive to the PE-coated cartons.

[0040] (2) Low-temperature adhesion test: Take 8 groups of identical PE-coated cartons, 10 in each group. Apply the 8 kinds of hot melt adhesives in the embodiments and comparative examples to the sealing interfaces of the 8 groups of PE-coated cartons, with a coating amount of 5 g / carton. Then place them in an environment with a temperature of -15°C and a humidity of 70% for 24 days, and test the average broken area of ​​the cartons when peeling off the sealing interface of the cartons. The larger the broken area, the better the low-temperature adhesion performance of the hot melt adhesive to the PE-coated cartons.

[0041] (3) Moisture resistance test: Take 8 groups of identical PE-coated cartons, 10 in each group. Apply the 8 kinds of hot melt adhesives in the embodiments and comparative examples to the sealing interfaces of the 8 groups of PE-coated cartons, with a coating amount of 5 g / carton. Then place them in an environment with a temperature of 25°C and a humidity of 70% for 24 hours, transfer them to an environment with a temperature of 25°C and a humidity of 90% and place them for 180 days. Then test the average broken area of ​​the cartons when peeling off the sealing interface of the cartons. The larger the broken area, the better the waterproof property of the hot melt adhesive.

[0042] (4) Low-temperature flexibility: The hot melt adhesives in the embodiments and comparative examples were made into hot melt adhesive sheets with a size of 75 mm*10 mm*1.25 mm. The hot melt adhesive sheets corresponding to the embodiments and comparative examples were then placed in an environment of -20°C for 24 h. Twenty samples were randomly selected from each group, and the minimum core shaft diameters that different hot melt adhesive sheets could withstand were tested with reference to HG / T 4222-2011.

[0043] Table 1 The difference between Comparative Example 1 and Example 1 is that the maleic anhydride grafted POE polyolefin elastomer is replaced by an equal amount of POE polyolefin elastomer, and the difference between Comparative Example 2 and Example 1 is that the maleic anhydride grafted SIS block copolymer is replaced by an equal amount of SIS block copolymer. Combined with the test results in Table 1, it can be seen that the addition of maleic anhydride grafted POE polyolefin elastomer and maleic anhydride grafted SIS block copolymer can effectively improve the bonding performance of the hot melt adhesive to the coated carton, and at the same time, it can further improve the bonding stability of the hot melt adhesive in a low temperature environment and a humid environment, and can improve the bonding durability of the hot melt adhesive. In addition, the addition of maleic anhydride grafted POE polyolefin elastomer and maleic anhydride grafted SIS block copolymer can further improve the low-temperature flexibility of the hot melt adhesive, because the addition of maleic anhydride grafted POE polyolefin elastomer and maleic anhydride grafted SIS block copolymer can improve the compatibility of EVA resin, POE polyolefin elastomer and SIS block copolymer.

[0044] The difference between Comparative Example 3 and Example 1 is that the ratio of each component is different. Combined with the test results in Table 1, it can be seen that the ratio of each component also affects the bonding performance and low-temperature performance of the hot melt adhesive to the coated carton, indicating that the ratio of each component in the present application is also the key feature of the present application to obtain a hot melt adhesive with good bonding effect on the coated carton and good low-temperature flexibility, and can maintain bonding durability in a humid environment or a low-temperature environment.

[0045] The difference between Example 4 and Example 1 is that an appropriate amount of vinyl silane coupling agent modified silica is also added to the hot melt adhesive, and the vinyl silane coupling agent modified silica is directly obtained by modifying silica with a vinyl silane coupling agent. Combined with the test results in Table 1, it can be seen that adding vinyl silane coupling agent modified silica can improve the bonding performance of the hot melt adhesive to the coated carton, further improve the waterproof performance of the hot melt adhesive, and improve the bonding stability of the hot melt adhesive in a humid environment.

[0046] The difference between Example 5 and Example 4 is that the preparation method of the vinyl silane coupling agent modified silica is different. Among them, the vinyl silane coupling agent modified silica in Example 5 adds a step of pre-modifying the silica using plasma technology. Combined with the test results in Table 1, it can be seen that in the process of preparing the vinyl silane coupling agent modified silica, adding the step of pre-modifying the silica using plasma technology can further enhance the bonding performance of the hot melt adhesive to the coated carton.

[0047] This specific implementation manner 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 specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A waterproof and sealing flexible hot melt adhesive, characterized in that: The invention comprises 65-70 parts by weight of EVA resin, 20-22 parts by weight of POE polyolefin elastomer, 5.5-6.5 parts by weight of maleic anhydride grafted POE polyolefin elastomer, 4.2-4.8 parts by weight of SIS block copolymer, 1.2-1.8 parts by weight of maleic anhydride grafted SIS block copolymer, 15-20 parts by weight of tackifier, 4-6 parts by weight of viscosity regulator and 1-1.5 parts by weight of antioxidant.

2. The waterproof and sealing flexible hot melt adhesive according to claim 1, characterized in that: The waterproof and sealing flexible hot melt adhesive also includes 1.8-2.4 parts by weight of vinyl silane coupling agent modified silica.

3. The waterproof and sealing flexible hot melt adhesive according to claim 2, characterized in that: The preparation method of the vinyl silane coupling agent modified silica comprises the following steps: S1, using plasma to etch the surface of silicon dioxide to obtain pre-modified silicon dioxide; S2. Add the pre-modified silica to the ethanol solution of the vinyl silane coupling agent, raise the temperature to 55-60° C., stir for reaction, centrifuge, wash and dry to obtain the vinyl silane coupling agent modified silica.

4. The waterproof and sealing flexible hot melt adhesive according to claim 3, characterized in that: In step S1, the particle size of the silicon dioxide is in the range of 10-20 μm.

5. The waterproof and sealing flexible hot melt adhesive according to claim 3, characterized in that: In step S1, the etching gas is a combination of CH3F and O2, the gas flow rate of CH3F is 10-15mL / min, the gas flow rate of O2 is 50-55mL / min, the pressure in the etching chamber is 25-35Pa, the RF power is 120-130W, and the etching time is 20-30s.

6. A waterproof and sealing flexible hot melt adhesive according to any one of claims 1 to 5, characterized in that: The vinyl acetate content of the EVA resin is 25-30%.

7. A waterproof and sealing flexible hot melt adhesive according to any one of claims 1 to 5, characterized in that: The melt index of the POE polyolefin elastomer is 5-10 g / 10 min (190° C., 2.16 kg), and the grafting rate of maleic anhydride in the maleic anhydride grafted POE polyolefin elastomer is 1.2-1.5%.

8. A waterproof and sealing flexible hot melt adhesive according to any one of claims 1 to 5, characterized in that: The melt index of the SIS block copolymer is 9-15 g / 10 min (200° C., 5 kg). In the maleic anhydride grafted SIS block copolymer, the grafting rate of maleic anhydride is 0.8-1.2%.

9. A waterproof and sealing flexible hot melt adhesive according to any one of claims 1 to 5, characterized in that: The tackifier is petroleum resin, the viscosity modifier is at least one of paraffin wax, polyethylene wax, and polypropylene wax, and the antioxidant is at least one of antioxidant 1010 and antioxidant 1076.

10. A method for preparing a waterproof and sealing flexible hot melt adhesive, based on the waterproof and sealing flexible hot melt adhesive according to any one of claims 1 to 9, characterized in that: The following steps are involved: Melting the viscosity modifier and the antioxidant uniformly according to the proportion to obtain a first mixture; Adding EVA resin, POE polyolefin elastomer, maleic anhydride grafted POE polyolefin elastomer, SIS block copolymer and maleic anhydride grafted SIS block copolymer to the first mixture, melting them uniformly, to obtain a second mixture; A tackifier is added to the second mixture and melted evenly to obtain a waterproof and sealing flexible hot melt adhesive.

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