EVA (Ethylene Vinyl Acetate) hot melt adhesive for packaging and preparation method thereof

Abstract

The invention relates to the technical field of hot melt adhesives, and discloses an EVA hot melt adhesive for packaging and a preparation method thereof, the EVA hot melt adhesive comprises the following raw materials: an ethylene-vinyl acetate copolymer, a tackifier, Fischer-Tropsch wax, maleic anhydride grafted polypropylene wax, a modified additive and a high-temperature-resistant component, and the high-temperature-resistant component is prepared by adding the modified additive. The prepared EVA hot melt adhesive has excellent mechanical properties and oxidation resistance, can avoid the phenomenon that the adhesive property of the EVA hot melt adhesive is reduced and cracks or falls off due to the fact that the EVA hot melt adhesive is oxidized in a humid and hot environment, is resistant to oxidation for a long time, prolongs the service life of the EVA hot melt adhesive, and improves the service life of the EVA hot melt adhesive by adding the high-temperature-resistant component and introducing a rigid benzo nitrogen-containing heterocyclic ring structure. The high-temperature-resistant EVA hot melt adhesive has high molecular bond breaking energy barrier, effectively improves the high temperature resistance of the EVA hot melt adhesive, has a flexible chain segment, can improve the flexibility of the EVA hot melt adhesive, widens the application range of the EVA hot melt adhesive, and has wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt adhesives, and in particular to an EVA hot melt adhesive for packaging and a preparation method thereof. Background Art

[0002] Hot melt adhesive is a solvent-free thermoplastic adhesive prepared by melt blending with thermoplastic polymer as the base material and adding modifying additives. Compared with traditional adhesives, hot melt adhesive is solvent-free, pollution-free, non-toxic, water-resistant, non-debonding, fast curing speed and can be bonded multiple times. It is known as a green adhesive. Hot melt adhesive is solid at room temperature. When used, it is heated and melted to a low-viscosity viscous state. After being coated on the surface of the substrate to be bonded, it can achieve a tight bond with the substrate after cooling. It is widely used in packaging, medical, daily necessities, etc. In the field, the materials of hot melt adhesive are divided into two types: traditional and degradable. The traditional hot melt adhesive is based on ethylene-vinyl acetate copolymer (EVA), polyurethane (PU), polyethylene terephthalate (PET), etc., and the degradable type is based on polylactic acid (PLA), polycaprolactone (PCL), etc. Ethylene-vinyl acetate copolymer (EVA) hot melt adhesive has strong adhesion to a variety of materials and low price. It is the most widely used hot melt adhesive. Therefore, it is necessary to study and improve EVA hot melt adhesive.

[0003] EVA hot melt adhesive is used in the packaging field, but there are still some shortcomings. EVA material has poor flexibility. When subjected to external force, EVA hot melt adhesive is prone to breakage or peeling. In addition, EVA material has a linear structure and does not have a cross-linked network. It will be deformed by heat in a high temperature environment, resulting in a weakening of the interaction force between the hot melt adhesive and the bonded substrate, resulting in a decrease in bonding strength. It is prone to accelerated aging, causing the EVA hot melt adhesive to crack or even fall off, affecting the service life of the EVA hot melt adhesive. The patent with publication number CN115216248B discloses an EVA glue for paper packaging and a preparation method thereof. The EVA glue includes the following raw materials: a high molecular polymer ethylene-vinyl acetate copolymer, a tackifier, wax, an antioxidant, an auxiliary agent, an additive, and deionized water. The prepared EVA glue has strong cohesive strength, bonding strength, and high temperature resistance. However, the patent has a general effect on improving the high temperature resistance of the EVA hot melt adhesive and does not have long-term antioxidant properties, which limits the application of the EVA hot melt adhesive to a certain extent. For this reason, the present invention provides an EVA hot melt adhesive for packaging, which can maintain stable performance and long service life in a high temperature environment, broadens the application range of the EVA hot melt adhesive, and has broad application prospects. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the object of the present invention is to provide an EVA hot melt adhesive for packaging and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An EVA hot melt adhesive for packaging comprises the following raw materials in parts by weight: 80-95 parts of ethylene-vinyl acetate copolymer, 10-15 parts of tackifier, 3-6 parts of Fischer-Tropsch wax, 1-3 parts of maleic anhydride grafted polypropylene wax, 3-6 parts of modified additives, and 3-5 parts of high temperature resistant components.

[0007] Furthermore, the tackifier is any one of petroleum resin, terpene resin or rosin resin.

[0008] Furthermore, the preparation method of the modified additive comprises the following steps:

[0009] Step A: dispersing talc powder in toluene to form a uniform dispersion, introducing nitrogen, raising the temperature to 40-50° C., adding an acyl chloride modifier and a catalyst, reacting for 2-4 hours, filtering, washing, and drying to obtain acyl chloride talc powder;

[0010] Step B: Add talc chloride to dimethyl sulfoxide, mix well, introduce nitrogen, add 5-aminosalicylic acid, react at room temperature for 4-6 hours, filter, wash and dry to obtain a modified additive.

[0011] By adopting the above-mentioned technical scheme, the talcum powder surface containing hydroxyl can react with the acyl chloride in the acyl chloride modifier structure under the action of a catalyst to produce an esterification reaction, and obtain the talcum powder with an acyl chloride group, and the acyl chloride talcum powder can react with the amino in the 5-aminosalicylic acid structure to produce an amidation reaction, and obtain a modified additive. The modified additive prepared by the present invention is organically modified to talcum powder, so that the talcum powder surface energy is reduced, thereby effectively improving the compatibility with the EVA matrix, avoiding talcum powder from agglomerating in the EVA matrix, making it uniformly dispersed in the EVA matrix, giving play to the advantages of talcum powder, enhancing the mechanical properties of EVA hot melt adhesive, in addition, after chemical bonding with 5-aminosalicylic acid, the prepared EVA hot melt adhesive has excellent antioxidant properties, on the one hand, avoiding the precipitation problem of small molecule antioxidant substances, and EVA hot melt adhesive has a long-lasting antioxidant property, and on the other hand, it is also avoided that the EVA hot melt adhesive is easily oxidized to cause the surface to crack or even fall off, and the service life of the EVA hot melt adhesive is extended.

[0012] Furthermore, in step A, the acyl chloride modifier is any one of terephthaloyl chloride, malonyl chloride, succinyl chloride, glutaryl chloride or adipoyl chloride.

[0013] Furthermore, in step A, the catalyst is triethylamine or pyridine.

[0014] Furthermore, the preparation method of the high temperature resistant component comprises the following steps:

[0015] S1: Add EPDM rubber to toluene, then place the system in a constant temperature water tank at 45-55°C, stir until the EPDM rubber is dissolved, add formic acid to adjust the pH, slowly add hydrogen peroxide, stir for 6-8h, pour acetone to precipitate, wash the precipitate, and vacuum dry to obtain modified EPDM rubber;

[0016] S2: Add modified EPDM rubber to xylene, mix well, introduce nitrogen, add 6-aminoquinoxaline, raise the temperature to 85-100°C, react for 6-8h, cool naturally after the reaction is completed, precipitate, wash and vacuum dry the product to obtain a high temperature resistant component.

[0017] By adopting the above technical scheme, under the action of formic acid and hydrogen peroxide, EPDM rubber can be epoxidized to obtain modified EPDM rubber, and the epoxy group in the modified EPDM rubber structure can react with the amino group in the 6-aminoquinoxaline structure to obtain a high temperature resistant component. The high temperature resistant component prepared by the present invention introduces a rigid benzene nitrogen-containing heterocyclic structure quinoxaline group, and the C=N in the structure has a high bond energy, so the high temperature resistant component has a high molecular bond breaking energy barrier, and needs to absorb higher heat to break or thermally decompose it. In addition, the flexible chain segment in the high temperature resistant component can effectively improve the flexibility of the EVA hot melt adhesive, avoid breaking or peeling when subjected to external force, resulting in a decrease in bonding performance. The high temperature resistant component structure contains hydroxyl groups generated by the reaction, which can be cross-linked with the EVA matrix under the action of maleic anhydride grafted polypropylene wax to form a network structure, the density of the EVA matrix is ​​improved, the cohesive strength can be enhanced, and the bonding force with the bonded substrate is stronger. At the same time, the improvement of the density of the EVA matrix can also prevent the thermal motion of the molecular chain, further enhance the high temperature resistance of the EVA hot melt adhesive, enable the EVA hot melt adhesive to maintain stable performance under high temperature environment, and broaden the application range of the EVA hot melt adhesive.

[0018] Furthermore, in S1, the pH is 2-3.

[0019] A method for preparing EVA hot melt adhesive for packaging, comprising the following steps:

[0020] Step 1: Add ethylene-vinyl acetate copolymer, tackifier and Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 100-120°C for 1-3 hours, wait until the temperature drops to 80-90°C, add maleic anhydride grafted polypropylene wax, modified additives and high temperature resistant components, set the speed to 100-300r / min, stir and mix for 1-3 hours to obtain a mixed material;

[0021] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 80-90°C, the middle section temperature to 110-125°C, the outlet section temperature to 90-100°C, the screw speed to 200-400r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0022] Beneficial effects of the present invention:

[0023] The present invention prepares modified additives and high-temperature resistant components and adds them to an EVA matrix, so that the prepared EVA hot-melt adhesive has excellent mechanical properties, antioxidant properties, high-temperature resistance and flexibility, a tensile strength of up to 31.5 MPa, an elongation at break of up to 185%, can maintain stable performance in a high-temperature environment, has a long service life, broadens the application range of the EVA hot-melt adhesive, and has broad application prospects.

[0024] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0026] Figure 1 This is the infrared spectrum of the modified additive prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] Preparation of modified additives

[0030] Step A: Disperse 3.2 g of talc powder in toluene to form a uniform dispersion, introduce nitrogen, raise the temperature to 45°C, add 2.8 g of malonyl chloride and 0.3 g of triethylamine, react for 3 h, filter, wash and dry to obtain chlorinated talc powder;

[0031] Step B: Add 3 g of talc chloride to dimethyl sulfoxide, mix well, introduce nitrogen, add 2 g of 5-aminosalicylic acid, react at room temperature for 5 h, filter, wash and dry to obtain a modified additive.

[0032] The potassium bromide tablet method was used to prepare the sample, and the modified additive was tested by infrared using Bruker TENSORⅡ Fourier transform infrared spectrometer. Figure 1 As shown, the spectral wavenumber test range is 4000cm -1 -500cm -1 , the analysis shows that in the infrared spectrum of the modified additive, 3038cm -1 The absorption peak of the carbon-hydrogen bond in the benzene ring appeared at 1746 cm -1 The absorption peak of the carbon-oxygen double bond in the ester group appeared at 1692 cm -1 The absorption peak of the carbon-oxygen double bond in the carboxyl group appeared at 1669 cm -1 The absorption peak of the carbon-oxygen double bond in the amide appeared at 1018 cm -1 The absorption peak of talc silicon-oxygen bond appears at .

[0033] Example 2

[0034] Preparation of high temperature resistant components

[0035] S1: 3.6 g of EPDM rubber was added to toluene, and the system was placed in a constant temperature water bath at 50°C. After stirring until the EPDM rubber was dissolved, 86% formic acid was added to adjust the pH to 2, and then 1.2 mL of 30% hydrogen peroxide was slowly added. The mixture was stirred for 8 h, and acetone was poured into the mixture for precipitation. The precipitate was washed and vacuum dried to obtain the modified EPDM rubber.

[0036] S2: Add 3.2g of modified EPDM rubber into xylene, mix well, introduce nitrogen, add 1g of 6-aminoquinoxaline, raise the temperature to 95°C, react for 6h, cool naturally after the reaction is completed, precipitate, wash and vacuum dry the product to obtain a high temperature resistant component.

[0037] The element content of the high temperature resistant component was determined using a PerkinElmer 2400 element analyzer. The test results showed that the nitrogen content in the high temperature resistant component was 8.79%. Since the modified EPDM rubber does not contain nitrogen, it can be inferred that the nitrogen in the high temperature resistant component is provided by 6-aminoquinoxaline.

[0038] Example 3

[0039] Preparation of EVA hot melt adhesive

[0040] Step 1: Add 80g of ethylene-vinyl acetate copolymer, 10g of rosin resin, and 3g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 100°C for 1h, and then lower the temperature to 80°C, add 1g of maleic anhydride grafted polypropylene wax, 3g of the modified additive prepared in Example 1, and 3g of the high temperature resistant component prepared in Example 2, set the speed to 100r / min, stir and mix for 1h, and obtain a mixed material;

[0041] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 80°C, the middle section temperature to 110°C, the outlet section temperature to 90°C, the screw speed to 200r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0042] Example 4

[0043] Preparation of EVA hot melt adhesive

[0044] Step 1: Add 85g of ethylene-vinyl acetate copolymer, 12g of rosin resin, and 4g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 105°C for 2h, wait until the temperature drops to 85°C, add 2g of maleic anhydride grafted polypropylene wax, 4g of the modified additive prepared in Example 1, and 4g of the high temperature resistant component prepared in Example 2, set the speed to 200r / min, stir and mix for 1h, and obtain a mixed material;

[0045] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 115°C, the outlet section temperature to 95°C, the screw speed to 300r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0046] Example 5

[0047] Preparation of EVA hot melt adhesive

[0048] Step 1: Add 90g of ethylene-vinyl acetate copolymer, 14g of rosin resin, and 5g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 110°C for 2h, and then lower the temperature to 90°C, add 3g of maleic anhydride grafted polypropylene wax, 5g of the modified additive prepared in Example 1, and 5g of the high temperature resistant component prepared in Example 2, set the speed to 250r / min, stir and mix for 2h, and obtain a mixed material;

[0049] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 120°C, the outlet section temperature to 95°C, the screw speed to 350r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0050] Example 6

[0051] Preparation of EVA hot melt adhesive

[0052] Step 1: Add 95g of ethylene-vinyl acetate copolymer, 15g of rosin resin, and 6g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 120°C for 3h, and then lower the temperature to 90°C, add 3g of maleic anhydride grafted polypropylene wax, 6g of the modified additive prepared in Example 1, and 5g of the high temperature resistant component prepared in Example 2, set the speed to 300r / min, stir and mix for 3h to obtain a mixed material;

[0053] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 90°C, the middle section temperature to 125°C, the outlet section temperature to 100°C, the screw speed to 400r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0054] Comparative Example 1

[0055] Preparation of EVA hot melt adhesive

[0056] Step 1: Add 85g of ethylene-vinyl acetate copolymer, 12g of rosin resin, and 4g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 105°C for 2h, wait until the temperature drops to 85°C, add 2g of maleic anhydride grafted polypropylene wax and 4g of the modified additive prepared in Example 1, set the speed to 200r / min, stir and mix for 1h to obtain a mixed material;

[0057] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 115°C, the outlet section temperature to 95°C, the screw speed to 300r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0058] Comparative Example 2

[0059] Preparation of EVA hot melt adhesive

[0060] Step 1: Add 85g of ethylene-vinyl acetate copolymer, 12g of rosin resin, and 4g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 105°C for 2h, wait until the temperature drops to 85°C, add 2g of maleic anhydride grafted polypropylene wax and 4g of the high temperature resistant component prepared in Example 2, set the speed to 200r / min, stir and mix for 1h to obtain a mixed material;

[0061] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 115°C, the outlet section temperature to 95°C, the screw speed to 300r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0062] Comparative Example 3

[0063] Preparation of EVA hot melt adhesive

[0064] Step 1: Add 85g of ethylene-vinyl acetate copolymer, 12g of rosin resin, and 4g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 105°C for 2h, wait until the temperature drops to 85°C, add 2g of maleic anhydride grafted polypropylene wax, 4g of talc, and 4g of the high temperature resistant component prepared in Example 2, set the speed to 200r / min, stir and mix for 1h to obtain a mixed material;

[0065] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 115°C, the outlet section temperature to 95°C, the screw speed to 300r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0066] Comparative Example 4

[0067] Preparation of EVA hot melt adhesive

[0068] Step 1: Add 85g of ethylene-vinyl acetate copolymer, 12g of rosin resin, and 4g of Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 105°C for 2h, wait until the temperature drops to 85°C, add 2g of maleic anhydride grafted polypropylene wax, 4g of the modified additive prepared in Example 1, and 4g of ethylene propylene diene monomer rubber, set the speed to 200r / min, stir and mix for 1h, and obtain a mixed material;

[0069] Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 85°C, the middle section temperature to 115°C, the outlet section temperature to 95°C, the screw speed to 300r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

[0070] Performance Testing

[0071] The EVA hot melt adhesives prepared in Examples 3 to 6 and Comparative Examples 1 to 4 were made into films by a hot press, and then prepared into samples that met the test specifications. According to the standard GB / T30776-2014, the tensile strength and elongation at break of the samples were tested to determine the mechanical properties and flexibility of the samples; after the samples were placed in an aging box at 100°C for 24 hours, the tensile strength of the samples was tested again to determine the antioxidant properties of the samples; the EVA hot melt adhesive was placed in a thermogravimetric analyzer to test the decomposition temperature of the EVA hot melt adhesive, and the heating rate was set to 10°C / min, and the temperature range was 50-500°C to determine the high temperature resistance of the EVA hot melt adhesive. The test results are shown in the following table:

[0072]

[0073] From the analysis of the above table, it can be seen that the EVA hot melt adhesives prepared in Examples 3 to 6 of the present invention have excellent mechanical properties, antioxidant properties, flexibility and high temperature resistance. Comparative Example 1 does not add a high temperature resistant component, and cannot utilize the introduced rigid benzo nitrogen-containing heterocyclic structure quinoxaline group and the cross-linked network structure formed with the EVA matrix to improve the high temperature resistance of the hot melt adhesive, as well as the flexible segments in the high temperature resistant component structure to enhance flexibility. Therefore, the high temperature resistance and flexibility are poor. The modified additive is added, and the mechanical properties and antioxidant properties are excellent. Comparative Example 2 does not add a modified additive, and cannot utilize talcum powder to graft antioxidant substances. The mechanical properties and antioxidant properties of high hot melt adhesive are poor, so the mechanical properties and antioxidant properties are poor. High temperature resistant components are added, and the high temperature resistance and flexibility are excellent; Comparative Example 3 adds talcum powder, and the mechanical properties are poor, which may be caused by the agglomeration of talcum powder in the EVA matrix, and no grafting with antioxidants, so the antioxidant properties are poor. High temperature resistant components are added, and the high temperature resistance and flexibility are excellent; Comparative Example 4 adds modified additives, and the mechanical properties and antioxidant properties are excellent. EPDM rubber is added, and no high temperature resistant groups are introduced, so the high temperature resistance is poor, it cannot form a cross-linked network structure with the EVA matrix, and the flexibility is poor.

[0074] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. An EVA hot melt adhesive for packaging, characterized in that: The invention comprises the following raw materials in parts by weight: 80-95 parts of ethylene-vinyl acetate copolymer, 10-15 parts of tackifier, 3-6 parts of Fischer-Tropsch wax, 1-3 parts of maleic anhydride grafted polypropylene wax, 3-6 parts of modified additives and 3-5 parts of high temperature resistant components.

2. The EVA hot melt adhesive for packaging according to claim 1, characterized in that: The tackifier is any one of petroleum resin, terpene resin or rosin resin.

3. The EVA hot melt adhesive for packaging according to claim 1, characterized in that: The preparation method of the modified additive comprises the following steps: Step A: dispersing talc powder in toluene to form a uniform dispersion, introducing nitrogen, raising the temperature to 40-50° C., adding an acyl chloride modifier and a catalyst, reacting for 2-4 hours, filtering, washing, and drying to obtain acyl chloride talc powder; Step B: Add talc chloride to dimethyl sulfoxide, mix well, introduce nitrogen, add 5-aminosalicylic acid, react at room temperature for 4-6 hours, filter, wash and dry to obtain a modified additive.

4. The EVA hot melt adhesive for packaging according to claim 3, characterized in that: In step A, the acyl chloride modifier is any one of terephthaloyl chloride, malonyl chloride, succinyl chloride, glutaryl chloride or adipoyl chloride.

5. The EVA hot melt adhesive for packaging according to claim 3, characterized in that: In step A, the catalyst is triethylamine or pyridine.

6. The EVA hot melt adhesive for packaging according to claim 1, characterized in that: The preparation method of the high temperature resistant component comprises the following steps: S1: Add EPDM rubber to toluene, then place the system in a constant temperature water tank at 45-55°C, stir until the EPDM rubber is dissolved, add formic acid to adjust the pH, slowly add hydrogen peroxide, stir for 6-8h, pour acetone to precipitate, wash the precipitate, and vacuum dry to obtain modified EPDM rubber; S2: Add modified EPDM rubber to xylene, mix well, introduce nitrogen, add 6-aminoquinoxaline, raise the temperature to 85-100°C, react for 6-8h, cool naturally after the reaction is completed, precipitate, wash and vacuum dry the product to obtain a high temperature resistant component.

7. The EVA hot melt adhesive for packaging according to claim 6, characterized in that: In S1, the pH is 2-3.

8. A method for preparing the EVA hot melt adhesive for packaging as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Add ethylene-vinyl acetate copolymer, tackifier and Fischer-Tropsch wax into a high-speed mixer and mix them evenly, then raise the temperature to 100-120°C for 1-3 hours, wait until the temperature drops to 80-90°C, add maleic anhydride grafted polypropylene wax, modified additives and high temperature resistant components, set the speed to 100-300r / min, stir and mix for 1-3 hours to obtain a mixed material; Step 2: Add the mixed material into a twin-screw extruder, set the inlet section temperature to 80-90°C, the middle section temperature to 110-125°C, the outlet section temperature to 90-100°C, the screw speed to 200-400r / min, melt extrude and granulate to obtain EVA hot melt adhesive.

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