High-cohesiveness EVA (Ethylene Vinyl Acetate) hot melt adhesive and preparation process thereof

Abstract

The invention relates to the technical field of ethylene-vinyl acetate copolymers, and discloses a high-cohesiveness EVA hot melt adhesive and a preparation process thereof.The high-cohesiveness EVA hot melt adhesive is prepared by adding the ethylene-vinyl acetate copolymer into a reaction kettle, heating and stirring, then adding terpene phenolic resin, hydroxyl phenyl acrylate grafted SEBS, auxiliaries, filler and antioxygen, stirring and mixing, and discharging to obtain the high-cohesiveness EVA hot melt adhesive. The EVA hot melt adhesive with high cohesiveness is obtained. The hydroxyl phenyl acrylate grafted SEBS can compatibilize EVA and terpene phenolic resin, so that the terpene phenolic resin can better improve the fluidity of the EVA hot melt adhesive, has a very good tackifying effect, improves the tensile shear strength and T peel strength of the EVA hot melt adhesive, and has excellent bonding performance.

Description

Technical Field

[0001] The invention relates to the technical field of ethylene-vinyl acetate copolymers, in particular to a high-adhesive EVA hot melt adhesive and a preparation process thereof. Background Art

[0002] EVA hot melt adhesive is mainly composed of EVA resin, tackifier, viscosity regulator, filler, etc. It is widely used in shoemaking, furniture, electronics, automobiles and other fields. In order to improve the wettability and bonding performance of EVA hot melt adhesive with the substrate, tackifiers need to be added, mainly terpene phenolic resin, petroleum-based resin, rosin resin, etc.

[0003] Terpene phenolic resin is a common tackifier with good tackifying effects, excellent heat resistance, and high aging resistance. Improving the compatibility of terpene phenolic resin with EVA can enhance the fluidity of EVA and improve the bonding properties of hot melt adhesives. Patent publication number CN119081584B discloses a high-polarity hot melt adhesive and its preparation method. Using terpene phenolic resin, polystyrene-modified rosin resin, SIS rubber, maleic anhydride-modified EVA resin, and EVA resin as raw materials, the prepared hot melt adhesive has advantages such as high polarity and fast drying. However, the hot melt adhesive has low tensile shear strength and poor peel strength, resulting in poor bonding properties. Summary of the Invention

[0004] The invention solves the problem of poor bonding performance of EVA hot melt adhesive.

[0005] The technical solution of the present invention is: a preparation process of a high-adhesive EVA hot melt adhesive: adding ethylene-vinyl acetate copolymer into a reactor, heating and stirring, adding terpene phenolic resin, hydroxyphenyl acrylate grafted SEBS, additives, fillers, and antioxidants, stirring and mixing for 10-20 minutes, and discharging to obtain a high-adhesive EVA hot melt adhesive.

[0006] Further, the temperature is raised to 130-150°C.

[0007] Furthermore, the mass ratio of ethylene-vinyl acetate copolymer, terpene phenolic resin, hydroxyphenyl acrylate grafted SEBS, additives, fillers, and antioxidants is 100:(35-60):(4-8):(18-26):(20-35):(1.2-2).

[0008] Furthermore, the filler includes calcium carbonate powder, talc or white carbon black.

[0009] Furthermore, the auxiliary agent includes paraffin wax, microcrystalline wax or polyethylene wax.

[0010] Furthermore, the antioxidant is antioxidant 1010, antioxidant 1076 or antioxidant 264.

[0011] Furthermore, the preparation process of hydroxyphenyl acrylate grafted SEBS is as follows: hydrogenated styrene-butadiene block copolymer SEBS, hydroxyphenyl acrylate monomer, and diisopropylbenzene peroxide in a mass ratio of 100:(7-16):(0.6-1) are mixed and added to a twin-screw extruder, melt-grafted at 160-170°C for 8-14 minutes, extruded, and the product is added to xylene, heated to 130-140°C, stirred, and then acetone is added. After filtering, the precipitate is extracted and purified with acetone to obtain hydroxyphenyl acrylate grafted SEBS.

[0012] Furthermore, the hydroxyphenyl acrylate monomer is 4-hydroxyphenyl acrylate (CAS registration number 3233-36-1) or 4-hydroxyphenyl methacrylate (CAS registration number 31480-93-0).

[0013] The beneficial technical effects of the present invention are as follows: the present invention uses diisopropylbenzene peroxide as an initiator to melt-graft hydroxyphenyl acrylate monomers onto SEBS, introduces acrylate polymer molecular chains containing phenolic hydroxyl groups into the side chains of SEBS, and then blends with the hot melt adhesive matrix EVA, a tackifier terpene phenolic resin, a filler, etc. to obtain a highly adhesive EVA hot melt adhesive. The main chain of the hydroxyphenyl acrylate grafted SEBS contains a polyethylene intercalated molecular chain similar to that of EVA, and the polyacrylate polymer introduced into the side chain also has good compatibility with EVA. In addition, the main chain of the grafted SEBS contains a benzene ring structure, and the polyacrylate polymer in the side chain contains the same phenolic hydroxyl group as the phenolic resin, so that the hydroxyphenyl acrylate grafted SEBS can compatibilize EVA and terpene phenolic resin, improve the compatibility between EVA and terpene phenolic resin, and enable the terpene phenolic resin to better improve the fluidity of the EVA hot melt adhesive, have a good tackifying effect, improve the tensile shear strength and T peel strength of the EVA hot melt adhesive, and have excellent bonding properties. DETAILED DESCRIPTION

[0014] Unless otherwise indicated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, the relevant terms and laboratory procedures used herein are those widely used in the relevant fields and routine procedures. To facilitate a better understanding of the present invention, definitions and explanations of relevant terms are provided below.

[0015] The following ethylene-vinyl acetate copolymer, active ingredient content 99%, Shandong Liansheng Chemical Co., Ltd. Hydrogenated styrene-butadiene block copolymer SEBS, model A1535H, Dongguan Longsheng Engineering Plastics Co., Ltd. Terpene phenolic resin model TAMANOL803-L, Shandong Deshang Chemical Co., Ltd.

[0016] Example 1

[0017] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 48 g of 4-hydroxyphenyl methacrylate, and 3.7 g of dicumyl peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 170° C. for 8 min, followed by extrusion. The product was added to xylene, heated to 130° C., stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxyphenyl acrylate-grafted SEBS.

[0018] (2) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 3.5 kg of terpene phenolic resin, 0.4 kg of hydroxyphenyl acrylate grafted SEBS, 2.3 kg of microcrystalline wax, 2.7 kg of talc powder, and 0.12 kg of antioxidant 1076, stir and mix for 15 minutes, and discharge to obtain a highly adhesive EVA hot melt adhesive.

[0019] Example 2

[0020] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 35 g of 4-hydroxyphenyl acrylate, and 3 g of diisopropylbenzene peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 160° C. for 12 min. The mixture was extruded. The product was added to xylene, heated to 130° C., stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxyphenyl acrylate-grafted SEBS.

[0021] (2) 10 kg of ethylene-vinyl acetate copolymer was added to a reactor, heated to 130 ° C, stirred, and then added with 4.2 kg of terpene phenolic resin, 0.52 kg of hydroxyphenyl acrylate grafted SEBS, 1.8 kg of paraffin wax, 3.2 kg of calcium carbonate powder, and 0.17 kg of antioxidant 264. The mixture was stirred and mixed for 20 minutes, and the material was discharged to obtain a highly adhesive EVA hot melt adhesive.

[0022] Example 3

[0023] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 80 g of 4-hydroxyphenyl methacrylate, and 5 g of dicumyl peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 160° C. for 14 min, followed by extrusion. The product was added to xylene, heated to 140° C., stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxyphenyl acrylate grafted SEBS.

[0024] (2) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 5 kg of terpene phenolic resin, 0.67 kg of hydroxyphenyl acrylate grafted SEBS, 2.6 kg of polyethylene wax, 3.5 kg of calcium carbonate powder, and 0.2 kg of antioxidant 1010, stir and mix for 20 minutes, and discharge to obtain a highly adhesive EVA hot melt adhesive.

[0025] Example 4

[0026] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 63 g of 4-hydroxyphenyl methacrylate, and 4.4 g of dicumyl peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 165° C. for 12 min. The mixture was extruded. The product was added to xylene, heated to 140° C., stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxyphenyl acrylate-grafted SEBS.

[0027] (2) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 150 ° C, stir, add 6 kg of terpene phenolic resin, 0.8 kg of hydroxyphenyl acrylate grafted SEBS, 2.3 kg of microcrystalline wax, 2 kg of white carbon black, and 0.15 kg of antioxidant 1010, stir and mix for 10 minutes, and discharge to obtain a highly adhesive EVA hot melt adhesive.

[0028] Comparative Example 1

[0029] (1) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 3.5 kg of terpene phenolic resin, 2.3 kg of microcrystalline wax, 2.7 kg of talc powder, and 0.12 kg of antioxidant 1076, stir and mix for 15 minutes, and discharge to obtain EVA hot melt adhesive.

[0030] Comparative Example 2

[0031] (1) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 3.5 kg of terpene phenolic resin, 0.4 kg of hydrogenated styrene-butadiene block copolymer SEBS, 2.3 kg of microcrystalline wax, 2.7 kg of talc powder, and 0.12 kg of antioxidant 1076, stir and mix for 15 minutes, and discharge to obtain EVA hot melt adhesive.

[0032] Comparative Example 3

[0033] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 48 g of hydroxyethyl acrylate, and 3.7 g of diisopropylbenzene peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 170°C for 8 min, and the mixture was extruded. The product was added to xylene, heated to 130°C, stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxyethyl acrylate grafted SEBS.

[0034] (2) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 3.5 kg of terpene phenolic resin, 0.4 kg of hydroxyethyl acrylate grafted SEBS, 2.3 kg of microcrystalline wax, 2.7 kg of talc powder, and 0.12 kg of antioxidant 1076, stir and mix for 15 minutes, and discharge to obtain a highly adhesive EVA hot melt adhesive.

[0035] Comparative Example 4

[0036] (1) 0.5 kg of hydrogenated styrene-butadiene block copolymer (SEBS), 48 g of 4-hydroxystyrene, and 3.7 g of diisopropylbenzene peroxide were mixed and added to a twin-screw extruder. Melt grafting was performed at 170°C for 8 min, followed by extrusion. The product was added to xylene, heated to 130°C, stirred, and then acetone was added. After filtering, the precipitate was extracted and purified with acetone to obtain hydroxystyrene-grafted SEBS.

[0037] (2) Add 10 kg of ethylene-vinyl acetate copolymer into a reactor, heat to 140 ° C, stir, add 3.5 kg of terpene phenolic resin, 0.4 kg of hydroxystyrene grafted SEBS, 2.3 kg of microcrystalline wax, 2.7 kg of talc powder, and 0.12 kg of antioxidant 1076, stir and mix for 15 minutes, and discharge to obtain EVA hot melt adhesive.

[0038] Table 1 Properties of hot melt adhesive

[0039]

[0040]

[0041] After testing, compared with comparative examples 1-4, the tensile shear strength of the EVA hot melt adhesive of each embodiment reached 5.64-7.58MPa, and the T peel strength reached 4.35-6.10kN / m. This is mainly because hydroxyphenyl acrylate grafted SEBS is added. The main chain of SEBS contains a polyethylene intercalated molecular chain similar to EVA, and the polyacrylate polymer introduced into the side chain also has good compatibility with EVA. In addition, the main chain of the grafted SEBS contains a benzene ring structure, and the polyacrylate polymer of the side chain contains the same phenolic hydroxyl group as the phenolic resin, so that the hydroxyphenyl acrylate grafted SEBS can compatibilize EVA and terpene phenolic resin, thereby improving the compatibility between the two. The terpene phenolic resin can better improve the fluidity of the EVA hot melt adhesive, has a good viscosity-increasing effect, significantly improves the bonding performance of the EVA hot melt adhesive, and has higher tensile shear strength and T peel strength.

[0042] 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 process for preparing a high-adhesive EVA hot melt adhesive, characterized in that: The preparation process comprises the following steps: adding ethylene-vinyl acetate copolymer into a reaction kettle, heating and stirring, adding terpene phenolic resin, hydroxyphenyl acrylate grafted SEBS, additives, fillers, and antioxidants, stirring and mixing, and discharging to obtain a high-adhesive EVA hot melt adhesive.

2. The high-adhesive EVA hot melt adhesive and its preparation process according to claim 1, characterized in that: The mass ratio of the ethylene-vinyl acetate copolymer, terpene phenolic resin, hydroxyphenyl acrylate grafted SEBS, auxiliary agent, filler and antioxidant is 100:(35-60):(4-8):(18-26):(20-35):(1.2-2).

3. The preparation process of the high-adhesive EVA hot melt adhesive according to claim 1, characterized in that: The filler includes calcium carbonate powder, talc or white carbon black.

4. The preparation process of the high-adhesive EVA hot melt adhesive according to claim 1, characterized in that: The auxiliary agent includes paraffin wax, microcrystalline wax or polyethylene wax.

5. The preparation process of the high-adhesive EVA hot melt adhesive according to claim 1, characterized in that: The antioxidant is antioxidant 1010, antioxidant 1076 or antioxidant 264.

6. The preparation process of the high-adhesive EVA hot melt adhesive according to claim 1, characterized in that: The preparation process of the hydroxyphenyl acrylate grafted SEBS is as follows: hydrogenated styrene-butadiene block copolymer SEBS, hydroxyphenyl acrylate monomer, and dicumyl peroxide are mixed, added into a twin-screw extruder for melt grafting, extruded, the product added into xylene, heated and stirred, and then acetone is added. After filtering, the precipitate is extracted and purified with acetone to obtain the hydroxyphenyl acrylate grafted SEBS.

7. The process for preparing the high-adhesive EVA hot melt adhesive according to claim 6, characterized in that: The temperature during the melt grafting is 160-170° C., and the time is 8-14 minutes.

8. The process for preparing the high-adhesive EVA hot melt adhesive according to claim 6, characterized in that: The mass ratio of the hydrogenated styrene-butadiene block copolymer SEBS, hydroxyphenyl acrylate monomer and dicumyl peroxide is 100:(7-16):(0.6-1).

9. The process for preparing the high-adhesive EVA hot melt adhesive according to claim 8, characterized in that: The hydroxyphenyl acrylate monomer is 4-hydroxyphenyl acrylate or 4-hydroxyphenyl methacrylate.

10. A high-adhesive EVA hot melt adhesive obtained by the preparation process according to any one of claims 1 to 9.

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