An EVA hot melt adhesive with high bonding performance and its preparation process

Abstract

The present invention discloses an EVA hot melt adhesive with high bonding performance and its preparation process, which relates to the technical field of hot melt adhesives. The preparation method includes the following steps: adding composite filler A, composite filler B, and EVA resin into an open mill for mixing. After cooling and discharging, it is placed in an anti-sticking container to obtain the mixed EVA resin. The mixed EVA resin is heated and melted, and rosin, paraffin, diisopropylbenzene peroxide, antioxidant, and flame retardant are added in sequence, stirred evenly, discharged, cooled, and formed to obtain the EVA hot melt adhesive. The proportion of each component in the EVA hot melt adhesive by mass fraction includes: 100 - 120 parts of EVA resin, 5 - 8 parts of composite filler A, 15 - 20 parts of composite filler B, 50 - 60 parts of rosin, 20 - 30 parts of paraffin, 2 - 3 parts of diisopropylbenzene peroxide, 2 - 3 parts of antioxidant, and 10 - 15 parts of flame retardant.

Description

Technical Field

[0001] The present invention relates to the technical field of hot melt adhesives, and specifically to an EVA hot melt adhesive with high bonding performance and its preparation process. Background Art

[0002] EVA (ethylene-vinyl acetate copolymer) hot melt adhesive, as an important bonding material, is widely used in many fields such as packaging, shoe materials, automobiles, and electronics. It has the advantages of being solvent-free, environmentally friendly, safe, and easy to use. However, with the continuous upgrading of industrial applications, the application performance of traditional EVA hot melt adhesives in certain specific fields can no longer meet the requirements of high standards. Especially in terms of bonding performance and flame retardant performance, the performance of traditional EVA hot melt adhesives has certain limitations.

[0003] Peel strength is one of the important indicators to measure the bonding performance of hot melt adhesives. Especially in application scenarios that require high-reliability and durable bonding, high peel strength directly affects the service life and stability of materials. Therefore, in some occasions with high performance requirements, such as electronic component encapsulation, building materials, and high-end packaging fields, EVA hot melt adhesives not only need to have excellent initial adhesion, but also should maintain a high peel strength during long-term use.

[0004] In addition, with the continuous improvement of requirements for safety and environmental protection, the flame retardant performance of EVA hot melt adhesives has also become one of the key concerns. In some flammable environments or occasions with extremely high safety requirements, such as automotive interiors and electronic component encapsulation, the flame retardant performance of adhesives is crucial. Traditional EVA hot melt adhesives are flammable when encountering fire, with a fast flame propagation speed, and harmful gases are generated during the combustion process, which poses a threat to the use safety. Therefore, developing an EVA hot melt adhesive that not only has high peel strength bonding performance but also excellent flame retardant performance has become an urgent problem to be solved in the current adhesive field. Summary of the Invention

[0005] The purpose of the present invention is to provide an EVA hot melt adhesive with high bonding performance and its preparation process to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation process of an EVA hot melt adhesive with high bonding performance: S1: Add γ-methacryloxypropyltrimethoxysilane and 5wt% aqueous solution of tetramethylammonium hydroxide into isopropanol, stir and react at room temperature for 6 - 6.5 h, remove water and isopropanol under vacuum, add the reaction product into toluene, heat to 90 - 92 °C and react for 4 - 4.5 h, remove toluene under vacuum to obtain POSS-V;

[0008] Further, in the preparation process of POSS-V, the mass ratio of γ-methacryloxypropyltrimethoxysilane to 5 wt% aqueous solution of tetramethylammonium hydroxide is 60.38:15.6;

[0009] S2: Add molybdenum disulfide to a hexane solution of 0.5 M n-butyllithium, stir evenly, heat to 100 - 101 °C and react for 4 - 4.5 h, cool, filter, wash with anhydrous hexane, and vacuum dry at 55 °C for 6 h to obtain Li x molybdenum disulfide; Add Li x molybdenum disulfide to deionized water, ultrasonically treat until hydrolysis, add ferrous sulfate heptahydrate, stir evenly, ultrasonically treat for 2 - 2.5 h, add ethanol, stir evenly, adjust the pH to 10, irradiate the reaction solution with γ-rays, vacuum filter, collect the product, wash with deionized water, and vacuum dry at 60 °C for 24 h to obtain molybdenum disulfide supported on iron oxide;

[0010] Further, in the preparation process of the molybdenum disulfide supported on iron oxide, the mass ratio of Li x molybdenum disulfide to ferrous sulfate heptahydrate is 1:(0.8 - 1.2)

[0011] Further, the γ-ray source is a cobalt source and the radiation dose is 30 kGy;

[0012] S3: Add the molybdenum disulfide supported on iron oxide to deionized water, disperse evenly, heat to 85 - 86 °C, add oleic acid, keep stirring and reacting under a nitrogen atmosphere for 1 - 1.5 h, filter, collect the product, wash alternately with deionized water and anhydrous ethanol, and vacuum dry at 50 °C for 24 h to obtain the surface-treated composite material; Add POSS-V to tetrahydrofuran, stir evenly, add the surface-treated composite material and azobisisobutyronitrile, heat to 60 - 62 °C and react for 24 h, vacuum filter, collect the product, wash alternately with tetrahydrofuran and anhydrous ethanol, and vacuum dry at 60 °C for 24 h to obtain composite filler A;

[0013] Further, in the preparation process of the surface-treated composite material, the mass ratio of the molybdenum disulfide supported on iron oxide to oleic acid is 1:(0.98 - 1);

[0014] Further, the addition rate of oleic acid is 0.45 g / min;

[0015] Further, in the preparation process of composite filler A, the mass ratio of POSS-V to the surface-treated composite material is 1:1;

[0016] S4: Ultrasonically disperse the magnetite particles in deionized water, heat to 85 - 86 °C, add oleic acid, keep warm and stir for reaction for 1 - 1.5 h under a nitrogen atmosphere, filter, collect the product, wash alternately with deionized water and absolute ethanol, and vacuum dry at 50 °C for 24 h to obtain surface-treated magnetite particles; ultrasonically disperse the surface-treated magnetite particles in an aqueous solution of 4 wt% polyvinyl alcohol, add 1 / 4 vinyl acetate monomer, emulsifier OP-10, and sodium dodecyl sulfate under a nitrogen atmosphere, perform pre-emulsification treatment for 30 - 35 min, heat to 75 - 76 °C, add 1 / 5 ammonium persulfate, keep warm and emulsify for 30 - 35 min, add the remaining 3 / 4 vinyl acetate monomer and 1 / 5 ammonium persulfate, keep warm and emulsify for 30 - 35 min, add the remaining 3 / 5 ammonium persulfate and divinylbenzene, heat to 80 - 82 °C and react for 1 - 1.5 h, separate with a magnet, wash alternately with deionized water and absolute ethanol, and vacuum dry at 50 °C for 24 h to obtain composite filler B;

[0017] Further, in the preparation process of the surface-treated magnetite particles, the mass ratio of magnetite particles to oleic acid is 1:(0.98 - 1);

[0018] Further, the addition rate of oleic acid is 0.45 g / min;

[0019] Further, in the preparation process of composite filler B, the proportion of each component by mass includes: 25 - 30 parts of surface-treated magnetite particles, 184.8 - 221.8 parts of vinyl acetate monomer, 4 - 5 parts of emulsifier OP-10, 2 - 3 parts of sodium dodecyl sulfate, 1.2 - 1.4 parts of ammonium persulfate, and 9 - 10 parts of divinylbenzene;

[0020] S5: Add composite filler A, composite filler B, and EVA resin into an open mill for mixing, place the cooled and discharged material in an anti-sticking container to obtain the mixed EVA resin, heat and melt the mixed EVA resin, sequentially add rosin, paraffin wax, diisopropylbenzene peroxide, antioxidant, and flame retardant, stir evenly, discharge, cool, and mold to obtain the EVA hot melt adhesive;

[0021] Further, in the preparation process of the EVA hot melt adhesive, the proportion of each component by mass includes: 100 - 120 parts of EVA resin, 5 - 8 parts of composite filler A, 15 - 20 parts of composite filler B, 50 - 60 parts of rosin, 20 - 30 parts of paraffin wax, 2 - 3 parts of diisopropylbenzene peroxide, 2 - 3 parts of antioxidant, and 10 - 15 parts of flame retardant.

[0022] Further, the EVA resin comprises a combination of an EVA copolymer and EVA43; wherein the melt index of the EVA copolymer is 150-200 dg / min, and the VA content is 28-30 wt%; the melt index of EVA43 is 43 dg / min, and the VA content is 32 wt%; the mass ratio of the EVA copolymer to EVA43 is (8.8-9.2):(0.8-1.2);

[0023] Further, the antioxidant comprises any one of antioxidant 1010, antioxidant 1076, antioxidant 1024, and antioxidant 168;

[0024] Further, the flame retardant comprises any one of melamine cyanurate and ammonium polyphosphate.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. In the present invention, ferrous sulfate is reduced to iron tetroxide nanoparticles under γ-ray irradiation and then deposited on molybdenum disulfide nanosheets to prepare molybdenum disulfide supported iron tetroxide; on the one hand, the catalytic carbonization ability of molybdenum disulfide supported iron tetroxide and the catalytic action of MoO3 generated by the oxidation and decomposition of molybdenum disulfide are used, and the synergistic catalysis of the two combines with the flame retardant to form a dense and stable carbon layer, inhibiting complete combustion and improving the flame retardant performance of the EVA hot melt adhesive; on the other hand, the deposition of iron tetroxide increases the surface roughness of the molybdenum disulfide nanosheets, which can act as physical cross-linking points in the EVA hot melt adhesive, enabling the molecular chains to entangle better and enhancing the bonding performance.

[0027] 2. In the present invention, the molybdenum disulfide supported iron tetroxide is further modified with oleic acid, and the self-made POSS-V is grafted onto the surface of the molybdenum disulfide supported iron tetroxide through the action of azobisisobutyronitrile. On the one hand, the cage-like structure of POSS can further improve the mechanical properties as a nano-filler in EVA, providing higher hardness, wear resistance and thermal stability, improving the interfacial compatibility and intermolecular interaction, and increasing the chemical affinity between the EVA hot melt adhesive and the surfaces of different materials, especially improving the bonding force to difficult-to-adhere materials (such as plastics or metals); on the other hand, the POSS prepared from γ-methacryloxypropyltrimethoxysilane has a relatively low reactivity with dicumyl peroxide, and has a relatively low impact on the crosslinking degree of the EVA hot melt adhesive itself, achieving the purpose of enhancing the thermal stability and bonding performance of the hot melt adhesive.

[0028] 3. The present invention prepares composite filler B by surface coating and modifying magnetic iron oxide particles with polyvinyl acetate. Through surface coating and modification, composite filler B can move more easily in the EVA hot melt adhesive matrix. On the one hand, it enhances the induced orientation effect of the chain segments, resulting in an increase in crystallinity. At the same time, due to the polar interaction between the polar vinyl acetate chain segments and the polyvinyl acetate coating layer of the iron oxide coated with polyvinyl acetate, the polar vinyl acetate chain segments in the EVA molecules are induced to move accordingly, resulting in an increase in polar chain segments on one side of the iron plate and an increase in non-polar chain segments on the side of the PE plate, thereby enhancing the adhesion of the hot melt adhesive to the iron plate and the PE plate. On the other hand, by adding composite filler B, composite filler A can be further dispersed, achieving the purpose of adjusting the processing performance of the EVA hot melt adhesive and improving the bonding performance of the EVA hot melt adhesive.

[0029] 4. The present invention further controls the ratio of EVA43 with a relatively low viscosity to the EVA copolymer to adjust the viscosity, fluidity, and wettability of the EVA hot melt adhesive, thereby making the peel strength performance of the EVA hot melt adhesive reach the best. Detailed implementation mode

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] In the following examples, the specifications of the EVA copolymer are as follows: the melt index is 150 dg / min, and the VA content is 28 wt%, purchased from DuPont; the specifications of EVA43 are as follows: the melt index is 43 dg / min, and the VA content is 32 wt%, purchased from Macklin Biochemical Co., Ltd.; the model of polyvinyl alcohol is PVA1788, purchased from Aladdin; the specifications of the magnetic iron oxide particles are as follows: the particle size is 0.19 mm, purchased from Aladdin; the rest of the raw materials are commercially available.

[0032] In the following examples, the preparation method of POSS-V includes the following steps:

[0033] 60.38 g of γ-methacryloxypropyltrimethoxysilane and 15.6 g of 5 wt% aqueous solution of tetramethylammonium hydroxide are added to 200 mL of isopropanol, and stirred at room temperature for 6 h. Water and isopropanol are removed under vacuum. The reaction product is added to 200 mL of toluene, heated to 90 °C and reacted for 4 h. Toluene is removed under vacuum to obtain POSS-V;

[0034] In the following examples, the preparation method of molybdenum disulfide supported on iron oxide includes the following steps:

[0035] 10 g of molybdenum disulfide was added to a hexane solution of 0.5 M n-butyllithium, stirred evenly, heated to 100 °C and reacted for 4 h, cooled, filtered, washed with anhydrous hexane, and vacuum dried at 55 °C for 6 h to obtain Li x molybdenum disulfide; 1 g of Li x molybdenum disulfide was added to 100 mL of deionized water, ultrasonically treated until hydrolysis occurred, 0.8 g of ferrous sulfate heptahydrate was added, stirred evenly, ultrasonically treated for 2 h, 100 mL of ethanol was added, stirred evenly, the pH was adjusted to 10, the reaction solution was irradiated with γ-rays, vacuum filtered, the product was collected, washed with deionized water, and vacuum dried at 60 °C for 24 h to obtain molybdenum disulfide supported iron oxide.

[0036] In the following examples, the preparation method of composite filler A includes the following steps:

[0037] 1 g of molybdenum disulfide supported iron oxide was added to 350 mL of deionized water, dispersed evenly, heated to 85 °C, 0.98 g of oleic acid was added, and the reaction was stirred under nitrogen atmosphere for 1 h, filtered, the product was collected, washed alternately with deionized water and anhydrous ethanol, and vacuum dried at 50 °C for 24 h to obtain a surface-treated composite material; 500 mg of POSS-V was added to 250 mL of tetrahydrofuran, stirred evenly, 500 mg of the surface-treated composite material and 90 mg of azobisisobutyronitrile were added, and the reaction was carried out at 60 °C for 24 h, vacuum filtered, the product was collected, washed alternately with tetrahydrofuran and anhydrous ethanol, and vacuum dried at 60 °C for 24 h to obtain composite filler A.

[0038] In the following examples, the preparation method of composite filler B includes the following steps:

[0039] 1 g of iron oxide particles was ultrasonically dispersed in 350 mL of deionized water, heated to 85 °C, oleic acid was added, and the reaction was stirred under nitrogen atmosphere for 1 h, filtered, the product was collected, washed alternately with deionized water and anhydrous ethanol, and vacuum dried at 50 °C for 24 h to obtain surface-treated iron oxide particles; 25 parts of the surface-treated iron oxide particles were ultrasonically dispersed in an aqueous solution of 500 mL of 4 wt% polyvinyl alcohol, 46.2 parts of vinyl acetate monomer, 4 parts of emulsifier OP-10, and 2 parts of sodium dodecyl sulfate were added under nitrogen atmosphere, pre-emulsified for 30 min, heated to 75 °C, 0.24 part of ammonium persulfate was added, emulsified for 30 min, the remaining 138.6 parts of vinyl acetate monomer and 0.24 part of ammonium persulfate were added, emulsified for 30 min, the remaining 0.72 part of ammonium persulfate and 9 parts of divinylbenzene were added, heated to 80 °C and reacted for 1 h, magnetically separated, washed alternately with deionized water and anhydrous ethanol, and vacuum dried at 50 °C for 24 h to obtain composite filler B.

[0040] Example 1: Preparation process of an EVA hot melt adhesive with high bonding performance: Add 5 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and mold to obtain the EVA hot melt adhesive.

[0041] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 8.8:1.2.

[0042] Example 2: Preparation process of an EVA hot melt adhesive with high bonding performance: Add 5 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and mold to obtain the EVA hot melt adhesive.

[0043] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 9:1.

[0044] Example 3: Preparation process of an EVA hot melt adhesive with high bonding performance: Add 5 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and mold to obtain the EVA hot melt adhesive.

[0045] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 9.2:0.8.

[0046] Example 4: Preparation process of an EVA hot melt adhesive with high bonding performance: Add 8 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and mold to obtain the EVA hot melt adhesive.

[0047] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 9:1.

[0048] Example 5: Preparation process of an EVA hot melt adhesive with high adhesion performance: Add 8 parts of composite filler A, 20 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and form to obtain the EVA hot melt adhesive.

[0049] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 9:1.

[0050] Comparative Example 1: Preparation process of an EVA hot melt adhesive with high adhesion performance: Add 5 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and form to obtain the EVA hot melt adhesive.

[0051] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 9.4:0.6.

[0052] Comparative Example 2: Preparation process of an EVA hot melt adhesive with high adhesion performance: Add 5 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin into an open mill for mixing. After cooling and discharging, place it in an anti-sticking container to obtain the mixed EVA resin. Heat and melt the mixed EVA resin, and sequentially add 50 parts of rosin, 20 parts of paraffin wax, 2 parts of diisopropylbenzene peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate. Stir evenly, discharge, cool, and form to obtain the EVA hot melt adhesive.

[0053] In the EVA resin, the mass ratio of the EVA copolymer to EVA43 is 8.6:1.4.

[0054] Comparative Example 3: Preparation process of an EVA hot melt adhesive with high adhesion performance: Preparation method of POSS-V, including the following steps: Add 60.38 g of KH-550 and 15.6 g of 5 wt% aqueous tetramethylammonium hydroxide solution into 200 mL of isopropanol, stir and react at room temperature for 6 h, vacuum-remove water and isopropanol, add the reaction product into 200 mL of toluene, heat to 90 °C and react for 4 h, vacuum-remove toluene to obtain POSS-V;

[0055] The remaining steps are the same as those in Example 1.

[0056] Comparative Example 4: A preparation process of an EVA hot melt adhesive with high bonding performance: 10 parts of composite filler A, 15 parts of composite filler B, and 100 parts of EVA resin are added to an open mill for mixing, and the material is placed in an anti-sticking container after cooling and discharging to obtain a mixed EVA resin, and the mixed EVA resin is heated to melt, and 50 parts of rosin, 20 parts of paraffin, 2 parts of diisopropyl peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate are added in sequence, stirred evenly, discharged, cooled, and formed to obtain an EVA hot melt adhesive.

[0057] In the EVA resin, the mass ratio of EVA copolymer:EVA43 is 8.8:1.2.

[0058] Comparative Example 5: A preparation process of an EVA hot melt adhesive with high bonding performance: 5 parts of composite filler A, 25 parts of composite filler B, and 100 parts of EVA resin are added to an open mill for mixing, and the material is placed in an anti-sticking container after cooling and discharging to obtain a mixed EVA resin, and the mixed EVA resin is heated to melt, and 50 parts of rosin, 20 parts of paraffin, 2 parts of diisopropyl peroxide, 2 parts of antioxidant 1010, and 10 parts of melamine cyanurate are added in sequence, stirred evenly, discharged, cooled, and formed to obtain an EVA hot melt adhesive.

[0059] In the EVA resin, the mass ratio of EVA copolymer:EVA43 is 8.8:1.2.

[0060] Experiment: Peel strength test: The EVA hot melt adhesive prepared in the above embodiments and comparative examples was heated and melted, and evenly coated on the surface of the iron plate with a thickness of 0.1 mm and a coating area of ​​100 mm×20 mm. The polycarbonate sheet was attached to the surface of the hot melt adhesive, and the mixture was kept warm and hot-pressed at 2.5 MPa for 50 min, then cooled to room temperature and kept under pressure for 15 min. A universal testing machine was used to clamp the PE sheet and the iron plate at the upper and lower ends of the fixture respectively. The upper fixture was raised at a rate of 200 mm / min to test the peel strength.

[0061] Flame retardant performance test: The EVA hot melt adhesive prepared in the above examples and comparative examples was heated, melted, cross-linked and solidified, and then prepared into a standard sample, which was subjected to a vertical burning test UL-94 and a limiting oxygen index test.

[0062] The experimental data are shown in Table 1 below.

[0063] Table 1 EVA hot melt adhesive experimental data table

[0064]

[0065] Conclusion: The EVA hot melt adhesive prepared by the present invention has excellent bonding performance and flame retardant properties.

[0066] In Comparative Example 1, the proportion of EVA43 in the preparation process of the EVA hot melt adhesive was too low, resulting in a decrease in peel strength and bonding performance.

[0067] In Comparative Example 2, the proportion of EVA43 in the preparation process of the EVA hot melt adhesive was too high, resulting in a decrease in peel strength and bonding performance.

[0068] In Comparative Example 3, KH550 was used to prepare POSS-V in the preparation process of the EVA hot melt adhesive, resulting in a decrease in peel strength and bonding performance.

[0069] In Comparative Example 4, the addition amount of composite filler A in the preparation process of the EVA hot melt adhesive was too high, resulting in a decrease in peel strength and bonding performance.

[0070] In Comparative Example 5, the addition amount of composite filler A in the preparation process of the EVA hot melt adhesive was too low, resulting in a decrease in peel strength and bonding performance.

[0071] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A preparation process of an EVA hot melt adhesive with high bonding performance, characterized in that: The composite filler A, the composite filler B and the EVA resin are added to an open mill for mixing, and the mixed EVA resin is placed in an anti-sticking container after cooling and discharging to obtain the mixed EVA resin, and the mixed EVA resin is heated and melted, and rosin, paraffin, diisopropylbenzene peroxide, antioxidant and flame retardant are added in sequence, stirred evenly, discharged, cooled and formed to obtain an EVA hot melt adhesive; In the preparation process of EVA hot melt adhesive, the proportion of each component by mass includes: EVA resin 100-120 parts, composite filler A 5-8 parts, composite filler B 15-20 parts, rosin 50-60 parts, paraffin 20-30 parts, dicumyl peroxide 2-3 parts, antioxidant 2-3 parts, flame retardant 10-15 parts; The EVA resin includes a combination of EVA copolymer and EVA43; wherein the mass ratio of EVA copolymer to EVA43 is (8.8-9.2):(0.8-1.2); the melt index of the EVA copolymer is 150-200 dg / min, and the VA content is 28-30wt%; the melt index of EVA43 is 43 dg / min, and the VA content is 32wt%; The preparation process of POSS-V comprises the following steps: adding γ-methacryloxypropyltrimethoxysilane and 5wt% tetramethylammonium hydroxide aqueous solution to isopropanol, stirring and reacting at room temperature for 6-6.5h, removing water and isopropanol in vacuum, adding the reaction product to toluene, heating to 90-92°C for reaction for 4-4.5h, and removing toluene in vacuum to obtain POSS-V; The preparation process of molybdenum disulfide loaded ferrosoferric oxide comprises the following steps: adding molybdenum disulfide to a 0.5M hexane solution of n-butyl lithium, stirring evenly, heating to 100-101°C for reaction for 4-4.5h, cooling, filtering, washing with anhydrous hexane, and vacuum drying at 55°C for 6h to obtain Lix molybdenum disulfide; adding Lix molybdenum disulfide to deionized water, ultrasonically treating to hydrolysis, adding ferrous sulfate heptahydrate, stirring evenly, ultrasonically treating for 2-2.5h, adding ethanol, stirring evenly, adjusting the pH to 10, irradiating the reaction solution with gamma rays, vacuum filtering, collecting the product, washing, and vacuum drying to obtain molybdenum disulfide loaded ferrosoferric oxide; The preparation process of composite filler A comprises the following steps: adding molybdenum disulfide loaded ferrosilicate into deionized water, dispersing evenly, heating to 85-86°C, adding oleic acid, stirring and reacting for 1-1.5 hours under a nitrogen atmosphere, filtering, collecting products, washing with deionized water and anhydrous ethanol alternately, and vacuum drying to obtain a surface-treated composite material; adding POSS-V into tetrahydrofuran, stirring evenly, adding the surface-treated composite material and azobisisobutyronitrile, heating to 60-62°C for reaction for 24 hours, vacuum filtering, collecting products, washing, and vacuum drying to obtain composite filler A; The preparation process of composite filler B comprises the following steps: ultrasonically dispersing ferroferric oxide particles in deionized water, heating to 85-86°C, adding oleic acid, stirring and reacting under a nitrogen atmosphere for 1-1.5h, filtering, collecting products, washing, and vacuum drying to obtain surface-treated ferroferric oxide particles; ultrasonically dispersing the surface-treated ferroferric oxide particles in a 4wt% aqueous solution of polyvinyl alcohol, adding 1 / 4 vinyl acetate monomer, emulsifier OP-10, and sodium dodecyl sulfate under a nitrogen atmosphere, pre-emulsifying for 30-35min, heating to 75-76°C, adding 1 / 5 ammonium persulfate, emulsifying for 30-35min, adding the remaining 3 / 4 vinyl acetate monomer and 1 / 5 ammonium persulfate, emulsifying for 30-35min, adding the remaining 3 / 5 ammonium persulfate and divinylbenzene, heating to 80-82°C for 1-1.5h, separating with a magnet, washing, and vacuum drying to obtain composite filler B.

2. The preparation process of the EVA hot melt adhesive with high bonding performance according to claim 1, characterized in that: During the preparation of the surface-treated composite material, the mass ratio of molybdenum disulfide loaded ferrosoferric oxide: oleic acid was 1:(0.98-1); during the preparation of the composite filler A, the mass ratio of POSS-V: surface-treated composite material was 1:

1.

3. The preparation process of the EVA hot melt adhesive with high bonding performance according to claim 1, characterized in that: In the preparation process of the surface-treated ferroferric oxide particles, the mass ratio of ferroferric oxide particles to oleic acid is 1:(0.98-1); During the preparation of composite filler B, the proportions of the components by mass include: 25-30 parts of surface treated ferrosoferric oxide particles, 184.8-221.8 parts of vinyl acetate monomer, 4-5 parts of emulsifier OP-10, 2-3 parts of sodium dodecyl sulfate, 1.2-1.4 parts of ammonium persulfate, and 9-10 parts of divinylbenzene.

4. The preparation process of the EVA hot melt adhesive with high bonding performance according to claim 1, characterized in that: During the preparation of POSS-V, the mass ratio of γ-methacryloxypropyltrimethoxysilane: 5 wt % tetramethylammonium hydroxide aqueous solution was 60.38:15.

6.

5. The process for preparing an EVA hot melt adhesive with high bonding performance according to claim 1, characterized in that: During the preparation of molybdenum disulfide loaded ferrosiferous oxide, the mass ratio of Li x molybdenum disulfide: ferrous sulfate heptahydrate is 1:(0.8-1.2).

6. EVA hot melt adhesive prepared according to the preparation process of an EVA hot melt adhesive with high bonding performance according to any one of claims 1 to 5.

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