阅读说明：本技术 一种耐高低温热熔胶、其制备方法及应用 (High-low temperature resistant hot melt adhesive, and preparation method and application thereof ) 是由 饶小波 田杨 应泽人 王志 乔孟雅 刘立辉 于 2021-09-10 设计创作，主要内容包括：本发明属于粘合材料的技术领域,公开了一种耐高低温热熔胶、其制备方法及应用,耐高低温热熔胶包括高熔指基材、低熔指基材与助分散基材；高熔指基材的熔融指数大于300g/10min,低熔指基材的熔融指数小于100g/10min,助分散基材的熔融指数介于高熔指基材与低熔指基材之间；助分散基材用于对高熔指基材与低熔指基材在混料造粒加工过程中分散均匀；三者均为乙烯共聚物。本发明热熔胶用于双壁热收缩套管的内胶层,均能满足GMW17136标准,同时能满足ASTMD2671标准中规定的低温柔韧性测试-55℃/4h条件下不开裂的要求及125℃高温环境下的老化测试等性能要求。(The invention belongs to the technical field of adhesive materials, and discloses a high and low temperature resistant hot melt adhesive, a preparation method and application thereof, wherein the high and low temperature resistant hot melt adhesive comprises a high-melt-index base material, a low-melt-index base material and a dispersion-assisting base material; the melt index of the high-melt-index base material is more than 300g/10min, the melt index of the low-melt-index base material is less than 100g/10min, and the melt index of the dispersion-assisting base material is between the high-melt-index base material and the low-melt-index base material; the dispersion-assisting base material is used for uniformly dispersing the high-melting-index base material and the low-melting-index base material in the mixing and granulating process; all three are ethylene copolymers. The hot melt adhesive is used for the inner adhesive layer of the double-wall heat-shrinkable sleeve, can meet the GMW17136 standard, and can meet the requirements of low-temperature flexibility test specified in the ASTMD2671 standard, namely no cracking under the condition of 55 ℃/4h, aging test under the high-temperature environment of 125 ℃ and other performance requirements.)

1. A high-low temperature resistant hot melt adhesive is characterized by comprising a high-melt-index base material, a low-melt-index base material and a dispersion-aid base material; the melt index of the high-melt-index base material is more than 300g/10min, the melt index of the low-melt-index base material is less than 100g/10min, and the melt index of the dispersion-aid base material is between that of the high-melt-index base material and that of the low-melt-index base material; the dispersion-assisting base material is used for uniformly dispersing the high-melting-index base material and the low-melting-index base material in the mixing and granulating process; melt indices are all measured at 190 ℃/2.16kg under ASTM D1238 standard conditions;

the high-melting-index base material, the low-melting-index base material and the dispersion-aid base material are all ethylene copolymers.

2. The high and low temperature resistant hot melt adhesive according to claim 1, wherein: also comprises an antioxidant; the high-melting-index base material, the low-melting-index base material, the dispersion-aid base material and the antioxidant are prepared from (30-70): (5-20): (10-50): (1-3) according to the mass portion.

3. The high and low temperature resistant hot melt adhesive according to claim 1, wherein: the ethylene copolymer comprises ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-propyl acrylate copolymer, ethylene-propyl methacrylate copolymer, ethylene-butyl acrylate copolymer and ethylene-butyl methacrylate copolymer.

4. The high and low temperature resistant hot melt adhesive according to claim 3, characterized in that: the high-melting-index substrate, the low-melting-index substrate and the dispersion-assisting substrate are respectively any one or a combination of more of an ethylene-vinyl acetate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-propyl acrylate copolymer, an ethylene-propyl methacrylate copolymer, an ethylene-butyl acrylate copolymer and an ethylene-butyl methacrylate copolymer.

5. The high and low temperature resistant hot melt adhesive according to claim 1, wherein: the melt index of the high-melt-index base material is 300-600g/10 min; the low-melting index substrate has a melting index of 10-80g/10 min; the melt index of the dispersion-aid base material is 100-250g/10min, and the melt index is tested at 190 ℃/2.16kg under the standard condition of ASTM D1238.

6. The high and low temperature resistant hot melt adhesive according to claim 5, wherein: the high-melting index base material consists of a first high-melting base material, a second high-melting base material and a third high-melting base material;

the ethylene content of the first high-melting base material is 70-80 wt%, the softening point is 85-100 ℃, and the melt index is 400g/10 min; the viscosity is 150-300Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 50-60 ℃;

the ethylene content of the second high-melting base material is 65-75 wt%, the softening point is 75-90 ℃, and the melt index is 400-500g/10 min; the viscosity is 80-200Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-55 ℃;

the ethylene content of the third high melting base material is 50-65 wt%, the softening point is 70-85 ℃, and the melting index is 500-600g/10 min; the viscosity is 30-100Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 30-45 ℃;

the low-melting-point substrate consists of a first low-melting-point substrate, a second low-melting-point substrate and a third low-melting-point substrate;

the ethylene content of the first low-melting base material is 75-85 wt%, the softening point is 150-165 ℃, and the melt index is 10-30g/10 min; the viscosity is 3000-; the Vicat softening point is 60-70 ℃;

the ethylene content of the second low-melting base material is 60-75 wt%, the softening point is 120-140 ℃, and the melt index is 30-50g/10 min; the viscosity is 1500-; the Vicat softening point is 50-65 ℃;

the ethylene content of the third low-melting base material is 60-75 wt%, the softening point is 100-120 ℃, and the melt index is 50-80g/10 min; the viscosity is 800-1500Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-60 ℃;

the dispersion-assisting base material consists of a first dispersion base material, a second dispersion base material and a third dispersion base material;

the ethylene content of the first dispersion base material is 70-80 wt%, the softening point is 90-110 ℃, and the melt index is 100-150g/10 min; the viscosity is 900-1200Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 40-55 ℃;

the ethylene content of the second dispersion base material is 70-80 wt%, the softening point is 80-100 ℃, and the melt index is 150-200g/10 min; the viscosity is 500-800Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-55 ℃;

the ethylene content of the third dispersion base material is 70-80 wt%, the softening point is 70-90 ℃, and the melt index is 200-250g/10 min; the viscosity is 200-400Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 40-50 ℃.

7. The high and low temperature resistant hot melt adhesive according to claim 2, wherein: the antioxidant is any one or a combination of more of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid N-octadecyl ester, N '-bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, tris [2, 4-di-tert-butylphenyl ] phosphite, 4' -methylenebis (2, 6-di-tert-butylphenol), N '-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine and beta, beta' -thiodipropionic acid distearate.

8. The preparation method of the high and low temperature resistant hot melt adhesive according to any one of claims 1 to 7, characterized by comprising the following steps:

s1 preparation of high-melt-index base material, low-melt-index base material and dispersion-aid base material

Preparing a high-melt-index substrate: mixing the first high-melting base material, the second high-melting base material and the third high-melting base material according to the ratio of (0-40): (30-50): (10-60), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 60-120 ℃, and cooling by water and granulating to obtain a high-melt-index base material;

preparation of low-melting-index substrate: the first low-melting base material, the second low-melting base material and the third low-melting base material are mixed according to the proportion of (0-30): (20-50): (10-50), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling by water and granulating to obtain a low-melting-index base material;

preparation of dispersion-aid base material: mixing the first dispersion base material, the second dispersion base material and the third dispersion base material according to the proportion of (10-30): (0-40): (30-80), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

s2, preparation of the hot melt adhesive: taking 30-70 parts of high-melting-index base material, 10-50 parts of low-melting-index base material, 5-20 parts of dispersion-aid base material and 1-3 parts of antioxidant by weight, adding the mixture into a high-speed stirrer, mixing for 2-5min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

9. The application of the high and low temperature hot melt adhesive prepared by the preparation method of claim 8 in the inner adhesive layer of a double-wall heat shrinkable sleeve.

Technical Field

The invention belongs to the technical field of adhesive materials, and particularly relates to a high-low temperature resistant hot melt adhesive, and a preparation method and application thereof.

Background

The hot melt adhesive is an adhesive with certain plasticity, and the physical state of the hot melt adhesive changes along with the change of temperature within a certain temperature range, while the chemical properties of the hot melt adhesive are unchanged. Because the hot melt adhesive is non-toxic and tasteless, belongs to an environment-friendly chemical product, and because the hot melt adhesive product is solid, the hot melt adhesive has the characteristics of convenience in packaging, transportation, storage, no solvent, no pollution and the like, the hot melt adhesive is widely applied to the current industrial production process.

However, in the practical application process, people find that the existing hot melt adhesive is difficult to meet the processing requirements when bonding and processing some special materials. Specifically, processing of Expandable Polyethylene (EPE) is exemplified. The expandable polyethylene, also called pearl wool, is a high-foam polyethylene product which is not in a cross-linked closed-cell structure and is produced by extrusion by taking low-density polyethylene (LDPE) as a main raw material. Since it is a porous foam, the viscosity of the hot melt adhesive used is strictly required when the adhesive is bonded. The glue solution is easy to run off and leak due to the low viscosity of the hot melt glue, and the phenomenon of false adhesion or infirm adhesion is caused; and if the viscosity is too high, the wire is easy to draw, the adhered material is not easy to wet, and the adhesive wire is easy to pollute the adhered material.

The double-wall heat-shrinkable sleeve is composed of an outer layer made of radiation cross-linked polyolefin material and an inner layer made of specially designed hot-melt adhesive material. In the using process, the double-wall heat-shrinkable sleeve is heated, the adhesive layer is melted and bonded to the substrate to be protected when being heated, and the insulating, sealing and protecting effects are achieved after the adhesive layer is cooled and shaped. The insulating sealing protective device is mainly applied to the fields of aviation, aerospace, automobiles, household appliances, communication, petrochemical industry and the like, and has an insulating sealing protective effect on connectors, wire harnesses, cable joints and branches.

With the continuous development of economy, the demand of double-wall heat-shrinkable sleeves is more and more, and higher requirements are put on the material performance. In particular, in the field of automotive applications, the performance requirements of the inner glue layer material are very strict, and particularly in the application of some connectors, the double-wall heat-shrinkable sleeve can play a role in insulation sealing protection only by meeting the requirement of rapid shrinkage and simultaneously playing a role in highly bonding the outer sheath of the wire and the metal interface, and the inner glue layer is required to keep certain fluidity after being heated. Meanwhile, the requirements of no slippage of the double-wall heat shrinkable sleeve in a high-temperature environment and no cracking in a low-temperature environment are also met. At present, in the heat shrinkable tube industry, the inner rubber layer material can hardly meet the requirements at the same time. In order to meet the requirements, the development of the high-temperature and low-temperature resistant hot melt adhesive is bound to draw great attention.

Disclosure of Invention

The invention aims to provide a high-low temperature resistant hot melt adhesive, a preparation method and application thereof, and solves the technical problems of high-performance requirement of hot melt adhesive, no slippage at high temperature and no cracking at low temperature.

The technical scheme provided by the invention is as follows:

the first purpose of the invention is to provide: a high-low temperature resistant hot melt adhesive comprises a high-melt-index base material, a low-melt-index base material and a dispersion-aid base material; the melt index of the high-melt-index base material is more than 300g/10min, the melt index of the low-melt-index base material is less than 100g/10min, and the melt index of the dispersion-aid base material is between that of the high-melt-index base material and that of the low-melt-index base material; the dispersion-assisting base material is used for uniformly dispersing the high-melting-index base material and the low-melting-index base material in the mixing and granulating process; melt indices are all measured at 190 ℃/2.16kg under ASTM D1238 standard conditions;

the high-melting-index base material, the low-melting-index base material and the dispersion-aid base material are all ethylene copolymers.

Preferably, the high and low temperature resistant hot melt adhesive also comprises an antioxidant; the high-melting-index base material, the low-melting-index base material, the dispersion-aid base material and the antioxidant are prepared from (30-70): (5-20): (10-50): (1-3) according to the mass portion.

Preferably, the ethylene copolymer includes ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-propyl acrylate copolymer, ethylene-propyl methacrylate copolymer, ethylene-butyl acrylate copolymer and ethylene-butyl methacrylate copolymer.

Preferably, the high-melting-index substrate, the low-melting-index substrate and the dispersion-aid substrate are any one or a combination of more of an ethylene-vinyl acetate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-propyl acrylate copolymer, an ethylene-propyl methacrylate copolymer, an ethylene-butyl acrylate copolymer and an ethylene-butyl methacrylate copolymer respectively.

Preferably, the high-melt-index base material has a melt index of 300-600g/10 min; the low-melting index substrate has a melting index of 10-80g/10 min; the melt index of the dispersion-aid base material is 100-250g/10min, and the melt index is tested at 190 ℃/2.16kg under the standard condition of ASTM D1238.

Preferably, the high-melting index substrate is composed of a first high-melting substrate, a second high-melting substrate and a third high-melting substrate;

the ethylene content of the first high-melting base material is 70-80 wt%, the softening point is 85-100 ℃, and the melt index is 400g/10 min; the viscosity is 150-300Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 50-60 ℃;

the ethylene content of the second high-melting base material is 65-75 wt%, the softening point is 75-90 ℃, and the melt index is 400-500g/10 min; the viscosity is 80-200Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-55 ℃;

the ethylene content of the third high melting base material is 50-65 wt%, the softening point is 70-85 ℃, and the melting index is 500-600g/10 min; the viscosity is 30-100Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 30-45 ℃;

the low-melting-point substrate consists of a first low-melting-point substrate, a second low-melting-point substrate and a third low-melting-point substrate;

the ethylene content of the first low-melting base material is 75-85 wt%, the softening point is 150-165 ℃, and the melt index is 10-30g/10 min; the viscosity is 3000-; the Vicat softening point is 60-70 ℃;

the ethylene content of the second low-melting base material is 60-75 wt%, the softening point is 120-140 ℃, and the melt index is 30-50g/10 min; the viscosity is 1500-; the Vicat softening point is 50-65 ℃;

the ethylene content of the third low-melting base material is 60-75 wt%, the softening point is 100-120 ℃, and the melt index is 50-80g/10 min; the viscosity is 800-1500Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-60 ℃;

the dispersion-assisting base material consists of a first dispersion base material, a second dispersion base material and a third dispersion base material;

the ethylene content of the first dispersion base material is 70-80 wt%, the softening point is 90-110 ℃, and the melt index is 100-150g/10 min; the viscosity is 900-1200Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 40-55 ℃;

the ethylene content of the second dispersion base material is 70-80 wt%, the softening point is 80-100 ℃, and the melt index is 150-200g/10 min; the viscosity is 500-800Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 45-55 ℃;

the ethylene content of the third dispersion base material is 70-80 wt%, the softening point is 70-90 ℃, and the melt index is 200-250g/10 min; the viscosity is 200-400Pa.s, and the test is carried out at 190 ℃ under the standard condition of GB/T2794-2013; the Vicat softening point is 40-50 ℃.

Preferably, the antioxidant is any one or more of pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], N-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, N '-bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, tris [2, 4-di-tert-butylphenyl ] phosphite, 4' -methylenebis (2, 6-di-tert-butylphenol), N '-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine, and distearate of β, β' -thiodipropionate.

The second purpose is to provide a preparation method of the high and low temperature resistant hot melt adhesive, which comprises the following steps:

s1 preparation of high-melt-index base material, low-melt-index base material and dispersion-aid base material

Preparing a high-melt-index substrate: mixing the first high-melting base material, the second high-melting base material and the third high-melting base material according to the ratio of (0-40): (30-50): (10-60), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 60-120 ℃, and cooling by water and granulating to obtain a high-melt-index base material;

preparation of low-melting-index substrate: the first low-melting base material, the second low-melting base material and the third low-melting base material are mixed according to the proportion of (0-30): (20-50): (10-50), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling by water and granulating to obtain a low-melting-index base material;

preparation of dispersion-aid base material: mixing the first dispersion base material, the second dispersion base material and the third dispersion base material according to the proportion of (10-30): (0-40): (30-80), adding the mixture into a high-speed stirrer to mix for 2-5min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

s2, preparation of the hot melt adhesive: taking 30-70 parts of high-melting-index base material, 10-50 parts of low-melting-index base material, 5-20 parts of dispersion-aid base material and 1-3 parts of antioxidant by weight, adding the mixture into a high-speed stirrer, mixing for 2-5min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

The third purpose is to provide: the high and low temperature resistant hot melt adhesive prepared by the preparation method is applied to the inner adhesive layer of the double-wall heat shrinkable sleeve.

Has the advantages that:

the invention selects a high-melting-index substrate, a low-melting-index substrate and a dispersion-aid substrate as substrates and different ethylene copolymers, wherein the high-melting-index substrate, the low-melting-index substrate and the dispersion-aid substrate have different melt indexes.

The high-melt index substrate has a high melt index and can be used as a viscosity regulator of a low-melt index substrate without additionally adding a low-molecular-weight viscosity regulator. In the existing material, because of the addition of the low molecular weight viscosity regulator, the low molecular weight viscosity regulator is uniformly dispersed among molecular chains of the polymer through mixing and granulating, so that the attraction among the molecular chains of the polymer is sharply weakened, namely, the acting force among the molecular chains is reduced, the mobility of the molecular chains of the polymer is increased, the external plasticization effect on the polymer is realized, and the prepared hot melt adhesive is easy to become brittle in a low-temperature environment and has poor low-temperature resistance. Meanwhile, the hot melt adhesive is easy to flow in a high-temperature environment, and the prepared double-wall heat-shrinkable sleeve can slide when being applied to a connector with a special-shaped structure, so that the application of the double-wall heat-shrinkable sleeve fails.

The high-melting-index base material is a polymer, the molecular weight is low, the molecular weight viscosity regulator is large, the low-temperature resistance is excellent, the problem of low-temperature cracking does not exist, meanwhile, the inner glue layer of the prepared double-wall heat-shrinkable sleeve does not flow obviously in a high-temperature environment, the performance is excellent, and the problem that the double-wall heat-shrinkable sleeve fails in application due to slippage when the double-wall heat-shrinkable sleeve is applied to a connector with a special structure in a high-temperature environment is solved.

The assistant dispersing base material as the third component has a melt index between that of the high-melt-index base material and that of the low-melt-index base material. Because the difference of the melt indexes of the high-melting-index base material and the low-melting-index base material is large, the high-melting-index base material and the low-melting-index base material are difficult to disperse uniformly after being mixed and sheared and granulated by a double-screw extruder. The prepared high-temperature and low-temperature resistant hot melt adhesive is used as an inner adhesive layer, and particles are easy to appear on the inner wall of the prepared heat-shrinkable double-wall sleeve, so that the use is influenced. By adding the dispersion-assisting base material, the melt index of the dispersion-assisting base material is between that of the high-melt-index base material and that of the low-melt-index base material, and the dispersion-assisting base material is uniformly dispersed with the high-melt-index base material and the low-melt-index base material through material mixing and shearing granulation of a double-screw extruder, so that the heat-shrinkable double-wall pipe has stable performance, smooth inner wall, no influence on normal use and excellent performance.

The hot melt adhesive prepared by the invention is used for the inner adhesive layer of the double-wall heat-shrinkable sleeve, and because of the original performance of the adhesive, the hot melt adhesive keeps excellent fluidity in the heating and shrinking process, can be quickly filled into a connecting gap after being heated, and plays a role in efficient insulation sealing protection.

The existing commercially available hot melt adhesives use low molecular weight petroleum resins, rosin, terpene resins, polyethylene wax and the like as viscosity regulators, and the viscosity regulators play an external plasticizing role on the copolymers and are used for reducing acting force among the molecules of the copolymers. But the prepared hot melt adhesive is brittle in a low-temperature environment (particularly at-55 ℃), and has poor low-temperature resistance; meanwhile, the hot melt adhesive is easy to flow in a high-temperature environment, and the prepared double-wall heat-shrinkable sleeve can slide when being applied to a connector with a special-shaped structure, so that the application of the double-wall heat-shrinkable sleeve fails.

The hot melt adhesive prepared by the invention can simultaneously highly bond the sheath of the wire and the metal interface, and because the sheath of the conventional wire is made of PVC and PE, the high and low temperature resistant hot melt adhesive is a copolymer of ethylene, a polymer chain of the copolymer contains a chain segment which is the same as that of PE, and the wire bonding property with the PE substrate is excellent according to the principle of similar compatibility of macromolecules. Meanwhile, the ethylene copolymer used in the invention, such as ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-propyl acrylate copolymer, ethylene-butyl acrylate copolymer and the like, contains polar groups, has excellent adhesion performance to PVC containing polar groups, and meanwhile, the copolymer containing polar groups can generate extremely strong interfacial tension on metal surfaces and can well adhere to metal interface surfaces.

The three base materials interact with each other, and the prepared hot melt adhesive keeps excellent fluidity and has extremely strong high temperature resistance in the application process. The high fluidity of the high-melt-index base material ensures that the prepared hot melt adhesive has excellent wettability and high fluidity in the application process. The low melting point means that the base material has excellent high temperature resistance due to high softening point, and the prepared hot melt adhesive has high temperature resistance. The introduction of the dispersion-assisting base material, the three base materials are melted and blended, and the high molecular chain of the dispersion-assisting base material firmly links the high molecular chain corresponding to the high-melting-finger base material and the high molecular chain corresponding to the low-melting-finger base material together to form an interpenetrating network structure, so that the occurrence of phase separation is avoided, and a homogeneous system is formed. Meanwhile, the three base materials have wide sources, the material price is lower than that of the polyamide hot melt adhesive, and the cost advantage is obvious.

High temperature non-slip: the invention takes three ethylene copolymers with different melt indexes as base materials, which all belong to high molecular materials, and in a high-temperature environment, compared with the use of a low-molecular-weight viscosity regulator, the ethylene copolymer has large viscosity and flow phase difference; meanwhile, in the process of preparing the double-wall heat-shrinkable tubing by taking the high-temperature and low-temperature resistant hot melt adhesive prepared by the invention as an inner adhesive layer, in an irradiation processing procedure, a medium-energy electron beam irradiates the surface of a material, the inner adhesive layer can generate certain crosslinking, so that the viscosity of the material of the inner adhesive layer is further increased under the same high-temperature environment, and the prepared double-wall heat-shrinkable tubing is particularly applied to a connector with a special-shaped structure, the inner adhesive layer can be firmly adhered to the surface of a base material, and meanwhile, the inner adhesive layer can lock an outer skin layer, so that the double-wall heat-shrinkable tubing cannot slide.

No cracking at low temperature: the invention takes three ethylene copolymers with different melt indexes as base materials, all belong to high molecular materials, have excellent low temperature resistance, and have no cracking condition under the low temperature condition, particularly under the environment of-55 ℃.

Other advantages are as follows: the base material used by the invention has wide source and lower price than polyamide hot melt adhesive, has obvious cost advantage and simultaneously meets the RoSH and REACH environmental protection grade requirements.

The high and low temperature resistant hot melt adhesive prepared by the invention can be directly and widely used in the fields of automobiles, aviation, aerospace, household appliances, communication, petrochemical industry and the like, and has remarkable economic and social benefits.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention is further described below with reference to specific embodiments, but these embodiments are only exemplary and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the principles of the invention and these changes and modifications are to be considered within the scope of the invention.

Example 1

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt-index base material consists of ethylene-ethyl acrylate copolymer (melt index of 300g/10min), ethylene-vinyl acetate copolymer (melt index of 450g/10min) and ethylene-ethyl methacrylate copolymer (melt index of 600g/10min) according to the mixture ratio of 20:50:30 by weight,

wherein the ethylene-ethyl acrylate copolymer (melt index 300g/10min) has an ethylene content of 76 wt%, a softening point of 87 ℃, a melt index of 300g/10min, a viscosity of 180Pa.s, and a Vicat softening point of 55 ℃.

Wherein the ethylene-vinyl acetate copolymer (melt index 450g/10min) has an ethylene content of 75 wt%, a softening point of 88 ℃ and a melt index of 450g/10 min; the viscosity was 170Pa.s and the Vicat softening point was 52 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 600g/10min) has an ethylene content of 60 wt%, a softening point of 77 ℃, a melt index of 600g/10min, a viscosity of 90Pa.s, and a Vicat softening point of 58 ℃.

Preparing a high-melt-index substrate: an ethylene-ethyl acrylate copolymer (melt index 300g/10min), an ethylene-vinyl acetate copolymer (melt index 450g/10min) and an ethylene-ethyl methacrylate copolymer (melt index 600g/10min) were mixed in a ratio of 20:50:30, adding the mixture into a high-speed stirrer, mixing for 3min, adding the stirred mixture into a double-screw extruder, mixing and granulating, wherein the processing temperature is 60-120 ℃, and cooling by water and granulating to obtain a high-melt index base material;

the low-melting-index base material is composed of ethylene-acrylic acid copolymer (with the melt index of 10g/10min), ethylene-butyl acrylate copolymer (with the melt index of 35g/10min) and ethylene-ethyl acrylate copolymer (with the melt index of 60g/10min) according to the mixture ratio of 10:50:40 by weight,

wherein the ethylene-acrylic acid copolymer (melt index 10g/10min) has an ethylene content of 78 wt%, a softening point of 162 ℃, a melt index of 10g/10min, a viscosity of 5000Pa.s, and a Vicat softening point of 68 ℃.

Wherein the ethylene-butyl acrylate copolymer (melt index 35g/10min) has an ethylene content of 72 wt%, a softening point of 132 ℃ and a melt index of 35g/10 min; the viscosity was 1700Pa.s and the Vicat softening point was 57 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 60g/10min) has an ethylene content of 67 wt%, a softening point of 112 ℃, a melt index of 60g/10min, a viscosity of 1200Pa.s, and a Vicat softening point of 58 ℃.

Preparation of low-melting-index substrate: mixing ethylene-acrylic acid copolymer (melt index 10g/10min), ethylene-butyl acrylate copolymer (melt index 35g/10min) and ethylene-butyl acrylate copolymer (melt index 35g/10min) according to the weight ratio of 10:50:40, adding the mixture into a high-speed stirrer, mixing for 5min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 80-160 ℃, and cooling by water and granulating to obtain a low-melting-index base material;

the dispersion-assisting base material consists of ethylene-methyl methacrylate copolymer (melt index 120g/10min), ethylene-butyl acrylate copolymer (melt index 180g/10min) and ethylene-ethyl methacrylate copolymer (melt index 220g/10min) according to the mixture ratio of 20:30:50 by mass,

wherein the ethylene-methyl methacrylate copolymer (melt index 120g/10min) has an ethylene content of 72 wt%, a softening point of 102 ℃, a melt index of 120g/10min, a viscosity of 980Pa.s, and a Vicat softening point of 48 ℃.

Wherein the ethylene-butyl acrylate copolymer (melt index 180g/10min) has an ethylene content of 75 wt%, a softening point of 95 ℃ and a melt index of 180g/10 min; the viscosity was 720Pa.s and the Vicat softening point was 52 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 220g/10min) has an ethylene content of 73 wt%, a softening point of 88 ℃, a melt index of 220g/10min, a viscosity of 350Pa.s, and a Vicat softening point of 48 ℃.

Preparation of dispersion-aid base material: mixing ethylene-methyl methacrylate copolymer (melt index 120g/10min), ethylene-butyl acrylate copolymer (melt index 180g/10min), ethylene-ethyl methacrylate copolymer (melt index 220g/10min) at a ratio of 20:30:50, adding the mixture into a high-speed stirrer, mixing for 2-5min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester.

The preparation method of the hot melt adhesive comprises the following steps: taking 70 parts by weight of high-melting-index base material, 18 parts by weight of low-melting-index base material, 10 parts by weight of dispersion-aid base material and 2 parts by weight of antioxidant, adding the mixture into a high-speed stirrer, mixing for 2min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Example 2

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt index base material consists of ethylene-methyl acrylate copolymer (melt index of 350g/10min), ethylene-ethyl methacrylate copolymer (melt index of 460g/10min) and ethylene-butyl acrylate copolymer (melt index of 550g/10min) according to the mixture ratio of 40:50:10 by weight,

wherein the ethylene-methyl acrylate copolymer (melt index 350g/10min) has an ethylene content of 75 wt%, a softening point of 86 ℃, a melt index of 350g/10min, a viscosity of 160Pa.s and a Vicat softening point of 52 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 460g/10min) has an ethylene content of 71 wt%, a softening point of 87 ℃ and a melt index of 460g/10 min; the viscosity was 240Pa.s and the Vicat softening point was 57 ℃.

Wherein the ethylene-butyl acrylate copolymer (melt index 550g/10min) has an ethylene content of 60 wt%, a softening point of 88 ℃, a melt index of 550g/10min, a viscosity of 276Pa.s, and a Vicat softening point of 58 ℃.

Preparing a high-melt-index substrate: adding an ethylene-methyl acrylate copolymer (with a melt index of 350g/10min), an ethylene-ethyl methacrylate copolymer (with a melt index of 460g/10min) and an ethylene-butyl acrylate copolymer (with a melt index of 550g/10min) into a high-speed stirrer according to the mass ratio of 40:50:10, mixing for 2min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-120 ℃, and cooling and granulating by water to obtain a high-melt-index base material;

the low-melting-index substrate is composed of ethylene-methacrylic acid copolymer (melt index is 18g/10min), ethylene-methyl methacrylate copolymer (melt index is 40g/10min) and ethylene-ethyl methacrylate copolymer (melt index is 80g/10min) according to the mixture ratio of 30:40:30 by weight,

wherein the ethylene-methacrylic acid copolymer (melt index 18g/10min) has an ethylene content of 75 wt%, a softening point of 156 ℃, a melt index of 18g/10min, a viscosity of 4600Pa.s, and a Vicat softening point of 66 ℃.

Wherein the ethylene-methyl methacrylate copolymer (melt index 40g/10min) has an ethylene content of 70 wt%, a softening point of 130 ℃ and a melt index of 40g/10 min; the viscosity is 1500Pa.s, and the Vicat softening point is 50 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 80g/10min) has an ethylene content of 60 wt%, a softening point of 120 ℃, a melt index of 80g/10min, a viscosity of 800Pa.s, and a Vicat softening point of 45 ℃.

Preparation of low-melting-index substrate: adding ethylene-methacrylic acid copolymer (with the melt index of 18g/10min), ethylene-methyl methacrylate copolymer (with the melt index of 40g/10min) and ethylene-ethyl methacrylate copolymer (with the melt index of 80g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 4min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling and granulating by water to obtain a low-melt index base material;

the dispersion-assisting base material is composed of an ethylene-propyl acrylate copolymer (with the melt index of 150g/10min), an ethylene-butyl methacrylate copolymer (with the melt index of 200g/10min) and an ethylene-ethyl methacrylate copolymer (with the melt index of 250g/10min) according to the mixture ratio of 30:40:30 in parts by weight.

Wherein the ethylene-propyl acrylate copolymer (melt index 150g/10min) has an ethylene content of 80 wt%, a softening point of 101 ℃, a melt index of 150g/10min, a viscosity of 950Pa.s, and a Vicat softening point of 45 ℃.

Wherein the ethylene-butyl methacrylate copolymer (melt index 200g/10min) has an ethylene content of 75 wt%, a softening point of 80 ℃ and a melt index of 200g/10 min; the viscosity was 500Pa.s and the Vicat softening point was 45 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 250g/10min) has an ethylene content of 70 wt%, a softening point of 82 ℃, a melt index of 250g/10min, a viscosity of 250Pa.s, and a Vicat softening point of 40 ℃.

Preparation of dispersion-aid base material: adding ethylene-propyl acrylate copolymer (melt index of 150g/10min), ethylene-butyl methacrylate copolymer (melt index of 200g/10min) and ethylene-ethyl methacrylate copolymer (melt index of 250g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-aid base material;

the antioxidant is compounded by pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and beta, beta' -thiodipropionic acid distearate according to the ratio of 3: 2.

The preparation method of the hot melt adhesive comprises the following steps: taking 30 parts by weight of high-melting-index base material, 19 parts by weight of low-melting-index base material, 50 parts by weight of dispersion-aid base material and 1 part by weight of antioxidant, adding the mixture into a high-speed stirrer, mixing for 3min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Comparative example 1

The high melt index substrate of this comparative example was replaced with low molecular weight viscosity modifier rosin and PE wax.

Wherein the softening point of the rosin is 80-95 ℃, and the viscosity is 400-6000 mPa.s.

Wherein the softening point of the PE wax is 110 ℃,

the low molecular weight viscosity regulator rosin is compounded with PE wax in a ratio of 1: 1.

The low-melting-index substrate is composed of ethylene-methacrylic acid copolymer (melt index is 18g/10min), ethylene-methyl methacrylate copolymer (melt index is 40g/10min) and ethylene-ethyl methacrylate copolymer (melt index is 80g/10min) according to the mixture ratio of 30:40:30 by weight,

wherein the ethylene-methacrylic acid copolymer (melt index 18g/10min) has an ethylene content of 75 wt%, a softening point of 156 ℃, a melt index of 18g/10min, a viscosity of 4600Pa.s, and a Vicat softening point of 66 ℃.

Wherein the ethylene-methyl methacrylate copolymer (melt index 40g/10min) has an ethylene content of 70 wt%, a softening point of 130 ℃ and a melt index of 40g/10 min; the viscosity is 1500Pa.s, and the Vicat softening point is 50 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 80g/10min) has an ethylene content of 60 wt%, a softening point of 120 ℃, a melt index of 80g/10min, a viscosity of 800Pa.s, and a Vicat softening point of 45 ℃.

Preparation of low-melting-index substrate: adding ethylene-methacrylic acid copolymer (with the melt index of 18g/10min), ethylene-methyl methacrylate copolymer (with the melt index of 40g/10min) and ethylene-ethyl methacrylate copolymer (with the melt index of 80g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 4min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling and granulating by water to obtain a low-melt index base material;

the dispersion-assisting base material is composed of an ethylene-propyl acrylate copolymer (with the melt index of 150g/10min), an ethylene-butyl methacrylate copolymer (with the melt index of 200g/10min) and an ethylene-ethyl methacrylate copolymer (with the melt index of 250g/10min) according to the mixture ratio of 30:40:30 in parts by weight.

Wherein the ethylene-propyl acrylate copolymer (melt index 150g/10min) has an ethylene content of 80 wt%, a softening point of 101 ℃, a melt index of 150g/10min, a viscosity of 950Pa.s, and a Vicat softening point of 45 ℃.

Wherein the ethylene-butyl methacrylate copolymer (melt index 200g/10min) has an ethylene content of 75 wt%, a softening point of 80 ℃ and a melt index of 200g/10 min; the viscosity was 500Pa.s and the Vicat softening point was 45 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 250g/10min) has an ethylene content of 70 wt%, a softening point of 82 ℃, a melt index of 250g/10min, a viscosity of 250Pa.s, and a Vicat softening point of 40 ℃.

Preparation of dispersion-aid base material: adding ethylene-propyl acrylate copolymer (melt index of 150g/10min), ethylene-butyl methacrylate copolymer (melt index of 200g/10min) and ethylene-ethyl methacrylate copolymer (melt index of 250g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-aid base material;

the antioxidant is compounded by pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and beta, beta' -thiodipropionic acid distearate according to the ratio of 3: 2.

The preparation method of the hot melt adhesive comprises the following steps: 30 parts of low-molecular-weight viscosity regulator rosin, 19 parts of low-melting-index base material, 50 parts of dispersion-aid base material and 1 part of antioxidant by weight are added into a high-speed stirrer to be mixed for 3min, the mixed mixture is added into a double-screw extruder to be mixed and granulated, the processing temperature is 60-180 ℃, and then the mixture is cooled and granulated to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Comparative example 2

The high melt index substrate of this comparative example uses a low molecular weight viscosity modifier terpene resin.

Wherein the softening point of the terpene resin is 80-120 ℃.

The low-melting-index substrate is composed of ethylene-methacrylic acid copolymer (melt index is 18g/10min), ethylene-methyl methacrylate copolymer (melt index is 40g/10min) and ethylene-ethyl methacrylate copolymer (melt index is 80g/10min) according to the mixture ratio of 30:40:30 by weight,

wherein the ethylene-methacrylic acid copolymer (melt index 18g/10min) has an ethylene content of 75 wt%, a softening point of 156 ℃, a melt index of 18g/10min, a viscosity of 4600Pa.s, and a Vicat softening point of 66 ℃.

Wherein the ethylene-methyl methacrylate copolymer (melt index 40g/10min) has an ethylene content of 70 wt%, a softening point of 130 ℃ and a melt index of 40g/10 min; the viscosity is 1500Pa.s, and the Vicat softening point is 50 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 80g/10min) has an ethylene content of 60 wt%, a softening point of 120 ℃, a melt index of 80g/10min, a viscosity of 800Pa.s, and a Vicat softening point of 45 ℃.

Preparation of low-melting-index substrate: adding ethylene-methacrylic acid copolymer (with the melt index of 18g/10min), ethylene-methyl methacrylate copolymer (with the melt index of 40g/10min) and ethylene-ethyl methacrylate copolymer (with the melt index of 80g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 4min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling and granulating by water to obtain a low-melt index base material;

the dispersion-assisting base material is composed of an ethylene-propyl acrylate copolymer (with the melt index of 150g/10min), an ethylene-butyl methacrylate copolymer (with the melt index of 200g/10min) and an ethylene-ethyl methacrylate copolymer (with the melt index of 250g/10min) according to the mixture ratio of 30:40:30 in parts by weight.

Wherein the ethylene-propyl acrylate copolymer (melt index 150g/10min) has an ethylene content of 80 wt%, a softening point of 101 ℃, a melt index of 150g/10min, a viscosity of 950Pa.s, and a Vicat softening point of 45 ℃.

Wherein the ethylene-butyl methacrylate copolymer (melt index 200g/10min) has an ethylene content of 75 wt%, a softening point of 80 ℃ and a melt index of 200g/10 min; the viscosity was 500Pa.s and the Vicat softening point was 45 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 250g/10min) has an ethylene content of 70 wt%, a softening point of 82 ℃, a melt index of 250g/10min, a viscosity of 250Pa.s, and a Vicat softening point of 40 ℃.

Preparation of dispersion-aid base material: adding ethylene-propyl acrylate copolymer (melt index of 150g/10min), ethylene-butyl methacrylate copolymer (melt index of 200g/10min) and ethylene-ethyl methacrylate copolymer (melt index of 250g/10min) into a high-speed stirrer according to the mass ratio of 30:40:30 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-aid base material;

the antioxidant is compounded by pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and beta, beta' -thiodipropionic acid distearate according to the ratio of 3: 2.

The preparation method of the hot melt adhesive comprises the following steps: 30 parts of low-molecular-weight viscosity regulator terpene resin, 19 parts of low-melting-index base material, 50 parts of dispersion-aid base material and 1 part of antioxidant by weight are added into a high-speed stirrer to be mixed for 3min, the mixed mixture is added into a double-screw extruder to be mixed and granulated, the processing temperature is 60-180 ℃, and then the mixture is cooled and granulated to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Example 3

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt index base material consists of ethylene-vinyl acetate copolymer (melt index 500g/10min) and ethylene-ethyl acrylate copolymer (melt index 550g/10min) according to the mixture ratio of 50:50 by weight,

wherein the ethylene-vinyl acetate copolymer (melt index 500g/10min) has an ethylene content of 67 wt%, a softening point of 78 deg.C, a melt index of 500g/10min, a viscosity of 81Pa.s, and a Vicat softening point of 46 deg.C.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 550g/10min) has an ethylene content of 55 wt%, a softening point of 87 ℃ and a melt index of 550g/10 min; the viscosity was 340Pa.s and the Vicat softening point was 32 ℃.

Preparing a high-melt-index substrate: adding ethylene-vinyl acetate copolymer (melt index 500g/10min) and ethylene-ethyl acrylate copolymer (melt index 550g/10min) into a high-speed stirrer according to the mass ratio of 50:50 for mixing for 3min, adding the stirred mixture into a double-screw extruder for mixing and granulating, wherein the processing temperature is 60-120 ℃, and cooling and granulating to obtain a high-melt-index base material;

the low-melting-index substrate is composed of ethylene-methyl acrylate copolymer (with a melt index of 40g/10min) and ethylene-propyl acrylate copolymer (with a melt index of 50g/10min) according to the mixture ratio of 50:50 by weight,

wherein the ethylene-methyl acrylate copolymer (melt index 40g/10min) has an ethylene content of 75 wt%, a softening point of 140 ℃, a melt index of 40g/10min, a viscosity of 2000Pa.s, and a Vicat softening point of 64 ℃.

Wherein the ethylene-propyl acrylate copolymer (melt index 50g/10min) has an ethylene content of 71 wt%, a softening point of 120 ℃ and a melt index of 50g/10 min; the viscosity was 1500Pa.s and the Vicat softening point was 52 ℃.

Preparation of low-melting-index substrate: adding ethylene-methyl acrylate copolymer (with a melt index of 40g/10min) and ethylene-propyl acrylate copolymer (with a melt index of 50g/10min) into a high-speed stirrer according to the mass ratio of 50:50, mixing for 2min, adding the stirred mixture into a double-screw extruder, mixing and granulating, wherein the processing temperature is 80-160 ℃, and cooling by water and granulating to obtain a low-melt-index base material;

the dispersion-assisting base material is composed of an ethylene-propyl acrylate copolymer (with the melt index of 100g/10min), an ethylene-butyl methacrylate copolymer (with the melt index of 150g/10min) and an ethylene-ethyl acrylate copolymer (with the melt index of 220g/10min) according to the mixture ratio of 10:10:80 in parts by weight.

Wherein the ethylene-propyl acrylate copolymer (melt index 100g/10min) has an ethylene content of 77 wt%, a softening point of 98 ℃, a melt index of 100g/10min, a viscosity of 1150Pa.s, and a Vicat softening point of 42 ℃.

Wherein, the ethylene-butyl methacrylate copolymer (the melt index is 150g/10min), the ethylene content is 72 wt%, the softening point is 99 ℃, and the melt index is 150g/10 min; the viscosity was 800Pa.s and the Vicat softening point was 45 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 220g/10min) has an ethylene content of 75 wt%, a softening point of 96 ℃, a melt index of 220g/10min, a viscosity of 220Pa.s, and a Vicat softening point of 42 ℃.

Preparation of dispersion-aid base material: adding ethylene-propyl acrylate copolymer (melt index 100g/10min), ethylene-butyl methacrylate copolymer (melt index 150g/10min) and ethylene-ethyl acrylate copolymer (melt index 220g/10min) into a high-speed stirrer according to the mass ratio of 10:10:80 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is a compound of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) N-octadecyl propionate, tris [2, 4-di-tert-butylphenyl ] phosphorous acid and N, N' -bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine in a ratio of 1:1: 1.

The preparation method of the hot melt adhesive comprises the following steps: taking 52 parts of high-melting-index base material, 5 parts of low-melting-index base material, 40 parts of dispersion-aid base material and 3 parts of antioxidant in parts by weight, adding the mixture into a high-speed stirrer to mix for 3min, adding the mixed mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 60-180 ℃, and then cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Example 4

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt-index base material consists of ethylene-butyl acrylate copolymer (melt index of 380g/10min), ethylene-ethyl methacrylate copolymer (melt index of 400g/10min) and ethylene-methyl acrylate copolymer (melt index of 580g/10min) according to the mixture ratio of 10:30:60 by weight,

wherein the ethylene-butyl acrylate copolymer (melt index 380g/10min) has an ethylene content of 76 wt%, a softening point of 85 ℃, a melt index of 380g/10min, a viscosity of 150Pa.s, and a Vicat softening point of 53 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 400g/10min) has an ethylene content of 74 wt%, a softening point of 85 ℃ and a melt index of 400g/10 min; the viscosity was 110Pa.s and the Vicat softening point was 57 ℃.

Wherein the ethylene-methyl acrylate copolymer (melt index 580g/10min) has an ethylene content of 59 wt%, a softening point of 78 deg.C, a melt index of 580g/10min, a viscosity of 60Pa.s, and a Vicat softening point of 40 deg.C.

Preparing a high-melt-index substrate: adding an ethylene-butyl acrylate copolymer (with a melt index of 380g/10min), an ethylene-ethyl methacrylate copolymer (with a melt index of 400g/10min) and an ethylene-methyl acrylate copolymer (with a melt index of 580g/10min) into a high-speed stirrer according to the mass ratio of 10:30:60, mixing for 2min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-120 ℃, and cooling and granulating by water to obtain a high-melt-index base material;

the low-melting-index substrate is composed of ethylene-methacrylic acid copolymer (with a melt index of 30g/10min), ethylene-ethyl acrylate copolymer (with a melt index of 50g/10min) and ethylene-ethyl methacrylate copolymer (with a melt index of 78g/10min) according to the mixture ratio of 10:40:50 by weight,

wherein the ethylene-methacrylic acid copolymer (melt index 30g/10min) has an ethylene content of 85 wt%, a softening point of 151 ℃, a melt index of 30g/10min, a viscosity of 3500Pa.s, and a Vicat softening point of 69 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 50g/10min) has an ethylene content of 66 wt%, a softening point of 137 ℃, a melt index of 50g/10min, a viscosity of 1800Pa.s, and a Vicat softening point of 54 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 78g/10min) has an ethylene content of 60 wt%, a softening point of 120 ℃, a melt index of 78g/10min, a viscosity of 830Pa.s, and a Vicat softening point of 46 ℃.

Preparation of low-melting-index substrate: adding ethylene-methacrylic acid copolymer (melt index 30g/10min), ethylene-ethyl acrylate copolymer (melt index 50g/10min) and ethylene-ethyl methacrylate copolymer (melt index 78g/10min) into a high-speed stirrer according to the mass ratio of 10:40:50 to mix for 3min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling by water and granulating to obtain a low-melt-index base material;

the dispersion-assisting base material is composed of an ethylene-methyl acrylate copolymer (the melt index is 150g/10min), an ethylene-butyl methacrylate copolymer (the melt index is 175g/10min) and an ethylene-ethyl acrylate copolymer (the melt index is 200g/10min) according to the mixture ratio of 20:20:60 in parts by weight.

Wherein the ethylene-methyl acrylate copolymer (melt index 150g/10min) has an ethylene content of 76 wt%, a softening point of 110 ℃, a melt index of 150g/10min, a viscosity of 920Pa.s and a Vicat softening point of 52 ℃.

Wherein the ethylene-butyl methacrylate copolymer (melting index is 175g/10min) has an ethylene content of 73 wt%, a softening point of 87 ℃ and a melting index of 175g/10 min; the viscosity was 750Pa.s and the Vicat softening point was 53 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 200g/10min) has an ethylene content of 76 wt%, a softening point of 88 ℃, a melt index of 200g/10min, a viscosity of 350Pa.s, and a Vicat softening point of 47 ℃.

Preparation of dispersion-aid base material: adding ethylene-methyl acrylate copolymer (with the melt index of 150g/10min), ethylene-butyl methacrylate copolymer (with the melt index of 175g/10min) and ethylene-ethyl acrylate copolymer (with the melt index of 200g/10min) into a high-speed stirrer according to the mass ratio of 20:20:60 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is a compound of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester and 4, 4' -methylenebis (2, 6-di-tert-butylphenol) according to the ratio of 1: 1.

The preparation method of the hot melt adhesive comprises the following steps: 68 parts of high-melting-index base material, 20 parts of low-melting-index base material, 10 parts of dispersion-aid base material and 2 parts of antioxidant are taken according to parts by weight, added into a high-speed stirrer and mixed for 3min, the mixed mixture is added into a double-screw extruder to be mixed and granulated, the processing temperature is 60-180 ℃, and then the mixture is cooled and granulated to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Example 5

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt index base material consists of ethylene-methyl acrylate copolymer (melt index 320g/10min), ethylene-ethyl methacrylate copolymer (melt index 450g/10min) and ethylene-methyl acrylate copolymer (melt index 520g/10min) according to the mixture ratio of 30:30:40 by weight,

wherein the ethylene-methyl acrylate copolymer (melt index 320g/10min) has an ethylene content of 70 wt%, a softening point of 100 ℃, a melt index of 320g/10min, a viscosity of 275Pa.s, and a Vicat softening point of 57 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 450g/10min) has an ethylene content of 70 wt%, a softening point of 86 ℃, a melt index of 450g/10min, a viscosity of 180Pa.s, and a Vicat softening point of 56 ℃.

Wherein the ethylene-methyl acrylate copolymer (melt index 520g/10min) has an ethylene content of 61 wt%, a softening point of 85 ℃, a melt index of 520g/10min, a viscosity of 61Pa.s, and a Vicat softening point of 41 ℃.

Preparing a high-melt-index substrate: adding ethylene-methyl acrylate copolymer (with a melt index of 320g/10min), ethylene-ethyl methacrylate copolymer (with a melt index of 450g/10min) and ethylene-methyl acrylate copolymer (with a melt index of 520g/10min) into a high-speed stirrer according to the mass ratio of 30:30:40 to mix for 2min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 60-120 ℃, and cooling by water and granulating to obtain a high-melt-index base material;

the low-melting-index substrate is composed of an ethylene-acrylic acid copolymer (with a melt index of 25g/10min), an ethylene-ethyl methacrylate copolymer (with a melt index of 55g/10min) and an ethylene-ethyl acrylate copolymer (with a melt index of 65g/10min) according to the mixture ratio of 30:30:40 by weight,

wherein the ethylene-acrylic acid copolymer (melt index 25g/10min) has an ethylene content of 78 wt%, a softening point of 158 ℃, a melt index of 25g/10min, a viscosity of 3700Pa.s, and a Vicat softening point of 68 ℃.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 55g/10min) has an ethylene content of 64 wt%, a softening point of 134 ℃, a melt index of 55g/10min, a viscosity of 1800Pa.s, and a Vicat softening point of 57 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 65g/10min) has an ethylene content of 60 wt%, a softening point of 118 ℃, a melt index of 65g/10min, a viscosity of 1300Pa.s, and a Vicat softening point of 57 ℃.

Preparation of low-melting-index substrate: adding ethylene-acrylic acid copolymer (with a melt index of 25g/10min), ethylene-ethyl methacrylate copolymer (with a melt index of 55g/10min) and ethylene-ethyl acrylate copolymer (with a melt index of 65g/10min) into a high-speed stirrer according to the mass ratio of 30:30:40, mixing for 3min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 80-160 ℃, and cooling with water and granulating to obtain a low-melt-index base material;

the dispersion-assisting base material is composed of an ethylene-methyl acrylate copolymer (the melt index is 120g/10min) and an ethylene-butyl acrylate copolymer (the melt index is 250g/10min) according to the mixture ratio of 30:70 in parts by weight.

Wherein the ethylene-methyl acrylate copolymer (melt index 120g/10min) has an ethylene content of 74 wt%, a softening point of 107 ℃, a melt index of 120g/10min, a viscosity of 1120Pa.s, and a Vicat softening point of 51 ℃.

Wherein, the ethylene-butyl acrylate copolymer (the melting index is 250g/10min), the ethylene content is 74 wt%, the softening point is 87 ℃, and the melting index is 250g/10 min; the viscosity was 350Pa.s and the Vicat softening point was 47 ℃.

Preparation of dispersion-aid base material: adding ethylene-methyl acrylate copolymer (with a melt index of 120g/10min) and ethylene-butyl acrylate copolymer (with a melt index of 250g/10min) into a high-speed stirrer according to the mass ratio of 30:70 for mixing for 3min, adding the stirred mixture into a double-screw extruder for mixing and granulating, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is the compound of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) N-octadecyl propionate and N, N' -bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine in a ratio of 1: 1.

The preparation method of the hot melt adhesive comprises the following steps: taking 50 parts by weight of high-melting-index base material, 10 parts by weight of low-melting-index base material, 38 parts by weight of dispersion-aid base material and 2 parts by weight of antioxidant, adding the mixture into a high-speed stirrer, mixing for 3min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Example 6

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high-melt-index base material consists of ethylene-ethyl acrylate copolymer (melt index of 320g/10min), ethylene-ethyl methacrylate copolymer (melt index of 420g/10min) and ethylene-butyl acrylate copolymer (melt index of 550g/10min) according to the mixture ratio of 10:40:50 by mass,

wherein the ethylene-ethyl acrylate copolymer (melt index 320g/10min) has an ethylene content of 74 wt%, a softening point of 97 deg.C, a melt index of 320g/10min, a viscosity of 284Pa.s, and a Vicat softening point of 55 deg.C.

Wherein the ethylene-ethyl methacrylate copolymer (melt index 420g/10min) has an ethylene content of 71 wt%, a softening point of 78 ℃, a melt index of 420g/10min, a viscosity of 110Pa.s and a Vicat softening point of 51 ℃.

Wherein the ethylene-butyl acrylate copolymer (melt index 550g/10min) has an ethylene content of 62 wt%, a softening point of 81 ℃, a melt index of 550g/10min, a viscosity of 47Pa.s and a Vicat softening point of 34 ℃.

Preparing a high-melt-index substrate: adding ethylene-ethyl acrylate copolymer (melt index of 320g/10min), ethylene-ethyl methacrylate copolymer (melt index of 420g/10min) and ethylene-butyl acrylate copolymer (melt index of 550g/10min) into a high-speed stirrer according to the mass ratio of 10:40:50 to mix for 3min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 60-120 ℃, and cooling by water and granulating to obtain a high-melt-index base material;

the low-melting-index substrate is composed of an ethylene-propyl acrylate copolymer (with the melt index of 26g/10min), an ethylene-ethyl acrylate copolymer (with the melt index of 45g/10min) and an ethylene-butyl methacrylate copolymer (with the melt index of 75g/10min) according to the mixture ratio of 40:50:10 by weight,

wherein the ethylene-propyl acrylate copolymer (melt index 26g/10min) has an ethylene content of 82 wt%, a softening point of 150 ℃, a melt index of 26g/10min, a viscosity of 4700Pa.s, and a Vicat softening point of 64 ℃.

Wherein the ethylene-ethyl acrylate copolymer (melt index 45g/10min) has an ethylene content of 66 wt%, a softening point of 128 ℃, a melt index of 45g/10min, a viscosity of 2200Pa.s, and a Vicat softening point of 57 ℃.

Wherein the ethylene-butyl methacrylate copolymer (melt index 75g/10min) has an ethylene content of 66 wt%, a softening point of 108 ℃, a melt index of 75g/10min, a viscosity of 1080Pa.s and a Vicat softening point of 53 ℃.

Preparation of low-melting-index substrate: adding ethylene-propyl acrylate copolymer (with the melt index of 26g/10min), ethylene-ethyl acrylate copolymer (with the melt index of 45g/10min) and ethylene-butyl methacrylate copolymer (with the melt index of 75g/10min) into a high-speed stirrer according to the mass ratio of 40:50:10 to mix for 3min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 80-160 ℃, and cooling and granulating the mixture to obtain a low-melt-index base material;

the dispersion-assisting base material is composed of an ethylene-butyl methacrylate copolymer (with a melt index of 120g/10min), an ethylene-butyl acrylate copolymer (with a melt index of 180g/10min) and an ethylene-butyl acrylate copolymer (with a melt index of 220g/10min) according to the mixture ratio of 10:20:70 in parts by weight.

Wherein the ethylene-butyl methacrylate copolymer (melt index 120g/10min) has an ethylene content of 73 wt%, a softening point of 105 ℃, a melt index of 120g/10min, a viscosity of 1160Pa.s, and a Vicat softening point of 52 ℃.

Wherein, the ethylene-butyl acrylate copolymer (melting index is 180g/10min), the ethylene content is 76 wt%, the softening point is 96 ℃, and the melting index is 180g/10 min; the viscosity was 630Pa.s and the Vicat softening point was 49 ℃.

Wherein the ethylene-butyl acrylate copolymer (melt index 220g/10min) has an ethylene content of 76 wt%, a softening point of 83 ℃, a melt index of 220g/10min, a viscosity of 380Pa.s and a Vicat softening point of 48 ℃.

Preparation of dispersion-aid base material: adding ethylene-butyl methacrylate copolymer (melt index 120g/10min), ethylene-butyl acrylate copolymer (melt index 180g/10min) and ethylene-butyl acrylate copolymer (melt index 220g/10min) into a high-speed stirrer according to the mass ratio of 10:20:70 to mix for 3min, adding the stirred mixture into a double-screw extruder to mix and granulate, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) n-octadecyl propionate.

The preparation method of the hot melt adhesive comprises the following steps: and (2) taking 69 parts by weight of high-melting-index base material, 15 parts by weight of low-melting-index base material, 15 parts by weight of dispersion-aid base material and 1 part by weight of antioxidant, adding the mixture into a high-speed stirrer, mixing for 3min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

Comparative example 3

The following conditions for the melt index test were 190 ℃/2.16kg and the test apparatus was a melt index apparatus.

The high melt of this comparative example means that the base material is replaced with a low molecular weight viscosity modifier petroleum resin.

Wherein the softening point of the petroleum resin is 120-130 ℃;

preparation of low-melting-index substrate: adding ethylene-acrylic acid copolymer (with a melt index of 25g/10min), ethylene-ethyl methacrylate copolymer (with a melt index of 55g/10min) and ethylene-ethyl acrylate copolymer (with a melt index of 65g/10min) into a high-speed stirrer according to the mass ratio of 30:30:40, mixing for 3min, adding the stirred mixture into a double-screw extruder, mixing and granulating at the processing temperature of 80-160 ℃, and cooling with water and granulating to obtain a low-melt-index base material;

the dispersion-assisting base material is composed of an ethylene-methyl acrylate copolymer (the melt index is 120g/10min) and an ethylene-butyl acrylate copolymer (the melt index is 250g/10min) according to the mixture ratio of 30:70 in parts by weight.

Wherein the ethylene-methyl acrylate copolymer (melt index 120g/10min) has an ethylene content of 74 wt%, a softening point of 107 ℃, a melt index of 120g/10min, a viscosity of 1120Pa.s, and a Vicat softening point of 51 ℃.

Wherein, the ethylene-butyl acrylate copolymer (the melting index is 250g/10min), the ethylene content is 74 wt%, the softening point is 87 ℃, and the melting index is 250g/10 min; the viscosity was 350Pa.s and the Vicat softening point was 47 ℃.

Preparation of dispersion-aid base material: adding ethylene-methyl acrylate copolymer (with a melt index of 120g/10min) and ethylene-butyl acrylate copolymer (with a melt index of 250g/10min) into a high-speed stirrer according to the mass ratio of 30:70 for mixing for 3min, adding the stirred mixture into a double-screw extruder for mixing and granulating, wherein the processing temperature is 70-140 ℃, and cooling by water and granulating to obtain a dispersion-assisting base material;

the antioxidant is the compound of beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) N-octadecyl propionate and N, N' -bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine in a ratio of 1: 1.

The preparation method of the hot melt adhesive comprises the following steps: taking 50 parts by weight of low molecular weight viscosity regulator petroleum resin, 10 parts by weight of low melting index base material, 38 parts by weight of dispersion-aid base material and 2 parts by weight of antioxidant, adding the mixture into a high-speed stirrer, mixing for 3min, adding the mixed mixture into a double-screw extruder, mixing and granulating at the processing temperature of 60-180 ℃, and cooling and granulating to obtain the high-temperature and low-temperature resistant hot melt adhesive.

The hot melt adhesives prepared in the above examples 1 to 6, which are resistant to high and low temperatures, and the hot melt adhesives of comparative examples 1 to 3 were subjected to the relevant tests, and the results thereof are shown in the following table 1.

TABLE 1

As can be seen from the parameters in the table 1, the hot melt adhesive provided by the invention, as an inner adhesive layer of a double-wall heat shrinkable sleeve, can meet the waterproof sealing performance requirement that the measured leakage current does not exceed 5 muA under the applied voltage of (14 +/-0.5) V specified in the GMW17136 standard, and can meet the performance requirements of low-temperature flexibility test specified in the ASTMD2671 standard, namely the requirement of no cracking under the condition of 55 ℃/4h and aging test under the high-temperature environment of 125 ℃ and the like.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.