Low-retraction irradiation crosslinking insulating material, preparation method thereof and application of low-retraction irradiation crosslinking insulating material in automobile wire

Abstract

The invention discloses a low-retraction irradiation crosslinking insulating material, a preparation method thereof and application of the low-retraction irradiation crosslinking insulating material in an automobile wire. The low-retraction irradiation crosslinking insulating material comprises the following raw materials: a resin matrix, a flame retardant and a crosslinking sensitizer, the resin matrix comprises high-density polyethylene, linear low-density polyethylene, a maleic anhydride grafted copolymer and an ethylene-butyl acrylate copolymer in a feeding mass ratio of 1: (0.2-0.7): (0.2-0.7): (0.3-0.85); the flame retardant comprises a granular flame retardant and a layered flame retardant in a feeding mass ratio of 1: (0.03-0.1); the preparation method comprises the following steps: weighing the raw materials according to the formula, uniformly mixing, extruding and granulating; the material disclosed by the invention is free from fracture when being impacted at a low temperature of-40 DEG C, and can be kept stable at a high temperature; and particularly, aiming at a light and thin insulating material for an automobile wire, such as an insulating material with a sectional area less than or equal to 0.5 mm < 2 >, the insulating material can obtain excellent and balanced effects in the aspects of low retraction, high temperature resistance, thin wall, mechanical property and the like.

Description

Technical Field

[0001] This invention relates to the field of insulating materials technology, and more particularly to materials used in automotive wiring harnesses, specifically to a low-shrinkage irradiated cross-linked insulating material, its preparation method, and its application in automotive wiring harnesses. Background Technology

[0002] In theory, low-shrinkage automotive wiring insulation materials can effectively maintain the shape and position of the insulation material during application, ensuring the stability and reliability of wire insulation. For example, they can be used in the connection parts of various wiring harnesses inside automobiles, such as wiring harness connections in the engine compartment, to protect wires and connectors from short circuits and electrical faults; they can also be used in the insulation layer of ABS brake lines to ensure stable signal transmission of the braking system and the insulation performance of the wires, ensuring the reliability and safety of the braking system.

[0003] However, with the rapid advancement of the automotive industry towards electrification and intelligentization, the widespread adoption of new energy vehicles has driven the upgrading of automotive wiring harnesses, placing stringent demands on the performance of insulation materials. For example, on the one hand, high-voltage wiring harnesses in new energy vehicles need to operate in high-temperature environments for extended periods, facing extreme temperature fluctuations ranging from -40℃ to 150℃; on the other hand, lightweight and compact automotive designs require insulation layers to become thinner. Under these circumstances, existing materials exhibit high shrinkage rates when subjected to high-temperature shocks, leading to poor adhesion between the insulation layer and the conductor, creating gaps, and potentially causing safety hazards such as partial discharge or insulation breakdown. In particular, when insulation materials are designed to be ultra-thin, it is difficult to balance low shrinkage, high-temperature resistance, thin-walled properties, and mechanical properties, resulting in a significant trade-off between these aspects. Summary of the Invention

[0004] The purpose of this invention is to overcome one or more deficiencies in the prior art and provide a new irradiated crosslinked insulating material that can solve at least one problem in the prior art.

[0005] The present invention also provides a method for preparing the above-mentioned irradiated crosslinked insulating material and its application in the preparation of automotive wire insulation materials, particularly for the preparation of thinner automotive wire insulation materials.

[0006] To achieve the above objectives, the present invention employs the following technical solution: An irradiated crosslinked insulating material, wherein the raw materials of the irradiated crosslinked insulating material include a resin matrix, a flame retardant, and a crosslinking sensitizer; The resin matrix includes high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), maleic anhydride graft copolymer and ethylene-butyl acrylate copolymer (EBA). The maleic anhydride graft copolymer has a Shore A hardness of 89-95, and the ethylene-butyl acrylate copolymer has a butyl acrylate mass content of 15%-25%. The mass ratio of the high-density polyethylene, the linear low-density polyethylene, the maleic anhydride graft copolymer, and the ethylene-butyl acrylate copolymer is 1:0.2-0.7:0.2-0.7:0.3-0.85. The flame retardant comprises particulate flame retardant and layered flame retardant, and the mass ratio of the particulate flame retardant to the layered flame retardant is 1:0.03-0.1.

[0007] In some embodiments of the present invention, the melt index of the high-density polyethylene is determined according to GB / T 3682.12018 standard at 190°C with a test load of 2.16 kg. The melt index is 2-8 g / 10 min, for example, it can be 2 g / 10 min, 3 g / 10 min, 3.5 g / 10 min, 4.0 g / 10 min, 4.5 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, etc.

[0008] In some embodiments of the present invention, the melt index of the linear low-density polyethylene is determined according to GB / T 3682.12018 standard at 190°C with a test load of 2.16 kg. The melt index is 10-20 g / 10 min, for example, 10 g / 10 min, 10.5 g / 10 min, 11 g / 10 min, 11.5 g / 10 min, 12 g / 10 min, or 12.5 g / 10 min. g / 10min, 13g / 10min, 13.5g / 10min, 14.0g / 10min, 14.5g / 10min, 15g / 10min, 15.5g / 10min, 16g / 10min, 1 6.5g / 10min, 17g / 10min, 17.5g / 10min, 18g / 10min, 18.5g / 10min, 19g / 10min, 19.5g / 10min, 20g / 10min, etc.

[0009] In some embodiments of the present invention, the melt index of the ethylene-butyl acrylate copolymer is determined according to GB / T 3682.12018 standard at 190°C with a test load of 2.16 kg. The melt index is 5-10 g / 10 min, for example, it can be 5 g / 10 min, 5.5 g / 10 min, 6 g / 10 min, 6.5 g / 10 min, 7 g / 10 min, 7.5 g / 10 min, 8 g / 10 min, 8.5 g / 10 min, 9 g / 10 min, 9.5 g / 10 min, 10 g / 10 min, etc.

[0010] In some embodiments of the present invention, the mass ratio of the resin matrix to the flame retardant is 1:1-2.2. Further, the mass ratio of the resin matrix to the flame retardant is 1:1.1-1.6, for example, it can be 1:1, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, 1:1.65, 1:1.7, 1:1.75, 1:1.8, 1:1.85, 1:1.9, 1:1.95, 1:2.0, 1:2.05, 1:2.1, 1:2.15, 1:2.2, etc.

[0011] In some embodiments of the present invention, the mass ratio of the high-density polyethylene, the linear low-density polyethylene, the maleic anhydride graft copolymer, and the ethylene-butyl acrylate copolymer is 1:0.3-0.6:0.3-0.6:0.4-0.75. According to certain specific aspects of the present invention, the numerical range "0.3-0.6" in "1∶0.3-0.6∶0.3-0.6∶0.4-0.75" can be 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, etc., and the numerical range "0.4-0.75" can be 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, etc.

[0012] In some embodiments of the present invention, the maleic anhydride graft copolymer is a maleic anhydride grafted polyolefin elastomer (maleic anhydride grafted POE) and / or a maleic anhydride grafted linear low-density polyethylene (maleic anhydride grafted LLDPE).

[0013] In some embodiments of the present invention, the crosslinking sensitizer is triallyl isocyanurate (TAIC) and / or trimethylolpropane trimethacrylate (TMPTMA).

[0014] In some embodiments of the present invention, the particulate flame retardant is aluminum hydroxide and / or magnesium hydroxide.

[0015] In some embodiments of the present invention, the layered flame retardant is a combination of one, two, or three selected from magnesium-aluminum silicate powder, hydrotalcite, and montmorillonite. Further, the layered flame retardant comprises magnesium-aluminum silicate powder and montmorillonite, with the selective addition of hydrotalcite; even further, the mass ratio of the magnesium-aluminum silicate powder, the montmorillonite, and the hydrotalcite is 1:0.15-0.4:0-0.25.

[0016] In some embodiments of the present invention, the raw materials of the irradiated crosslinking insulating material, by weight parts, include: 30-50 parts of high-density polyethylene, 10-20 parts of linear low-density polyethylene, 10-20 parts of maleic anhydride graft copolymer, 15-25 parts of ethylene-butyl acrylate copolymer, 110-130 parts of granular flame retardant, 5-10 parts of layered flame retardant, 2-4 parts of antioxidant, 2-4 parts of crosslinking sensitizer, 0.5-1.5 parts of silane coupling agent, and 1-4 parts of lubricant; wherein the total amount of the high-density polyethylene, the linear low-density polyethylene, the maleic anhydride graft copolymer, and the ethylene-butyl acrylate copolymer is 100 parts.

[0017] In some embodiments of the present invention, the antioxidant is selected from one, two or more combinations of antioxidant 1010, antioxidant 1035, antioxidant 1024, and antioxidant DLTP. Further, the antioxidant is composed of antioxidant 1010 and / or antioxidant 1035, antioxidant 1024, and antioxidant DLTP. Even further, the mass ratio of antioxidant 1010 and / or antioxidant 1035, antioxidant DLTP, and antioxidant 1024 is 1:0.4-0.6:0.15-0.35.

[0018] In some embodiments of the present invention, the silane coupling agent is silane 172.

[0019] In some embodiments of the present invention, the lubricant comprises silicone and / or PE wax.

[0020] Another technical solution provided by the present invention: a method for preparing the above-mentioned irradiation crosslinking insulating material, the preparation method comprising: weighing each raw material according to the formula, mixing and granulating, and extruding.

[0021] Furthermore, the method for preparing the irradiated crosslinked insulating material includes: Weigh out each raw material component according to the formula, mix them evenly in a kneader, knead them thoroughly, and then granulate them by extrusion through a twin-screw extruder.

[0022] Furthermore, the mixing temperature is 145-155℃.

[0023] Furthermore, the temperature of the twin-screw extruder is as follows: feed section: 100-130℃, melting section: 140-160℃, die head: 150-160℃, and the die head is equipped with a 100-150 mesh filter screen, which is used to filter impurities in the melt before extrusion granulation.

[0024] Another technical solution provided by the present invention: the application of the above-mentioned irradiation crosslinking insulating material in the preparation of automotive wiring insulation materials.

[0025] In some embodiments of the present invention, the cross-sectional area of ​​the automotive wire is less than or equal to 0.5 mm². 2 .

[0026] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: This invention provides a novel low-shrinkage irradiated cross-linked insulating material. Through the formulation and combination of the resin matrix and flame retardant, this insulating material achieves no cracking under impact at -40°C, while maintaining stability at high temperatures. For example, after cycling at 150°C, the shrinkage at both ends of the conductor is ≤0.5mm; this is particularly suitable for thinner materials, such as those with a cross-sectional area less than or equal to 0.5 mm². 2 The automotive wiring insulation material achieves superior and balanced performance in terms of low shrinkage, high temperature resistance, thin wall thickness, and mechanical properties, improving or even overcoming the problem of sacrificing some aspects in existing technologies. Detailed Implementation

[0027] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0028] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared using conventional methods in the art. In the following examples, the temperature values ​​of each section of the screw extruder may fluctuate under normal circumstances, generally within ±10 degrees Celsius, preferably controlled within ±5 degrees Celsius. The melt index of high-density polyethylene (HDPE) is 2.5 g / 10 min, the melt index of linear low-density polyethylene (LLDPE) is 18 g / 10 min, the Shore A hardness of maleic anhydride-grafted POE is 92, the melt index of EBA is 7 g / 10 min, and the mass content of butyl acrylate is 17%, all of which are commercially available.

[0029] Example 1: This embodiment provides an irradiated crosslinked insulating material and its preparation method. The raw materials for the irradiated crosslinked insulating material are shown in Table 1.

[0030] Table 1

[0031] The preparation method of the irradiated cross-linked insulating material includes: weighing various raw materials according to the formula, stirring them evenly in a kneader, kneading them at 150°C, and then granulating them by twin-screw extrusion; wherein, the feeding section is 115±10°C, the melting section is 150±10°C, and the die head is 155±5°C; a 120-mesh filter screen is installed in the die head.

[0032] Example 2: This embodiment provides an irradiated crosslinked insulating material and its preparation method. The raw materials for the irradiated crosslinked insulating material are shown in Table 2.

[0033] Table 2

[0034] The preparation method of this irradiated crosslinked insulating material is the same as in Example 1.

[0035] Example 3: This embodiment provides an irradiated crosslinked insulating material and its preparation method. The raw materials for the irradiated crosslinked insulating material are shown in Table 3.

[0036] Table 3

[0037] The preparation method of this irradiated crosslinked insulating material is the same as in Example 1.

[0038] Example 4: This embodiment provides an irradiated crosslinked insulating material and its preparation method. The raw materials for the irradiated crosslinked insulating material are shown in Table 4.

[0039] Table 4

[0040] The preparation method of this irradiated crosslinked insulating material is the same as in Example 1.

[0041] Comparative Example 1: This embodiment provides an irradiated crosslinked insulating material and its preparation method, which is basically the same as that in Embodiment 1, except that linear low-density polyethylene (LLDPE) is replaced with an equal mass of low-density polyethylene (LDPE) (melt index of 2.5 g / 10 min).

[0042] Comparative Example 2: This embodiment provides an irradiated crosslinked insulating material and its preparation method, which is basically the same as that in Embodiment 1, except that maleic anhydride-grafted POE is replaced with an equal mass of maleic anhydride-grafted EPDM rubber (melt index of 0.5 g / 10 min, Shore A hardness of 70).

[0043] Comparative Example 3: This embodiment provides an irradiated crosslinked insulating material and its preparation method, which is basically the same as that in Embodiment 1, except that: an ethylene-butyl acrylate copolymer with a butyl acrylate mass content of 8% and a melt index of 0.3 g / 10 min is selected.

[0044] Comparative Example 4: This embodiment provides an irradiated crosslinked insulating material and its preparation method, which is basically the same as that in Embodiment 1, except that the flame retardant 2 is replaced with an equal mass of inorganic aluminum hypophosphite.

[0045] Performance testing: The irradiated crosslinked insulating materials prepared in Examples 1-4 and Comparative Examples 1-4 were made into test pieces and tested for the following properties. Test piece preparation conditions: open mill temperature 160℃, vulcanizing press temperature 180℃, preheating for 10 min, and pressurizing for 5 min. The specific results are shown in Tables 5 and 6.

[0046] Table 5

[0047] Table 6

[0048] Note: √ indicates that the indicator meets the requirements, and × indicates that the indicator does not meet the requirements.

[0049] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0050] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An irradiation-crosslinked insulating material, characterized by, The raw material of the irradiation crosslinking insulation material comprises a resin matrix, a flame retardant and a crosslinking sensitizer; The resin matrix comprises high-density polyethylene, linear low-density polyethylene, maleic anhydride grafted copolymer and ethylene-butyl acrylate copolymer; The Shore A hardness of the maleic anhydride grafted copolymer is 89-95, and the mass content of butyl acrylate in the ethylene-butyl acrylate copolymer is 15%-25%; The mass ratio of the high-density polyethylene, the linear low-density polyethylene, the maleic anhydride grafted copolymer and the ethylene-butyl acrylate copolymer in the raw material is 1:0.2-0.7:0.2-0.7:0.3-0.85; The flame retardant comprises a particulate flame retardant and a layered flame retardant, and the mass ratio of the particulate flame retardant to the layered flame retardant in the raw material is 1:0.03-0.

1.

2. The irradiation crosslinked insulating material according to claim 1, characterized in that, The melt index of the high-density polyethylene is 2-8 g / 10 min, as determined according to GB / T 3682.1 2018 at 190°C under a test load of 2.16 kg; and / or, The melt index of the linear low-density polyethylene is 10-20 g / 10 min, as determined according to GB / T 3682.1 2018 at 190°C under a test load of 2.16 kg; and / or, The melt index of the ethylene-butyl acrylate copolymer is 5-10 g / 10 min, as determined according to GB / T 3682.1 2018 at 190°C under a test load of 2.16 kg.

3. The irradiation crosslinked insulating material according to claim 1, characterized in that, The mass ratio of the resin matrix to the flame retardant in the raw material is 1:1-2.2; and / or, the mass ratio of the high-density polyethylene, the linear low-density polyethylene, the maleic anhydride grafted copolymer and the ethylene-butyl acrylate copolymer in the raw material is 1:0.3-0.6:0.3-0.6:0.4-0.

75.

4. The irradiation crosslinked insulating material according to claim 1, characterized by The maleic anhydride grafted copolymer is maleic anhydride grafted polyolefin elastomer and / or maleic anhydride grafted linear low-density polyethylene; and / or, the mass ratio of the resin matrix to the flame retardant in the raw material is 1:1.1-1.6; and / or, the crosslinking sensitizer is triallyl isocyanurate and / or trimethylolpropane trimethacrylate.

5. The irradiation crosslinked insulating material of claim 1, wherein, The particulate flame retardant is aluminum hydroxide and / or magnesium hydroxide; and / or, the layered flame retardant is a combination of one, two or three selected from the group consisting of silicon-magnesium-aluminum powder, hydrotalcite and montmorillonite; further, the layered flame retardant comprises silicon-magnesium-aluminum powder and montmorillonite, and optionally hydrotalcite, and further, the mass ratio of the silicon-magnesium-aluminum powder, the montmorillonite and the hydrotalcite in the raw material is 1:0.15-0.4:0-0.

25.

6. The irradiation crosslinked insulating material of claim 1, wherein, The raw materials of the irradiation crosslinked insulating material include, in mass parts, high density polyethylene 30-50 parts, linear low density polyethylene 10-20 parts, maleic anhydride grafted copolymer 10-20 parts, ethylene-butyl acrylate copolymer 15-25 parts, particulate flame retardant 110-130 parts, laminar flame retardant 5-10 parts, antioxidant 2-4 parts, crosslinking sensitizer 2-4 parts, silane coupling agent 0.5-1.5 parts, lubricant 1-4 parts; wherein the total amount of the high density polyethylene, the linear low density polyethylene, the maleic anhydride grafted copolymer and the ethylene-butyl acrylate copolymer is 100 parts.

7. The irradiation crosslinked insulating material according to claim 6, characterized in that, The antioxidant is one, a combination of two or more selected from antioxidant 1010, antioxidant 1035, antioxidant 1024, antioxidant DLTP, further, the antioxidant is composed of antioxidant 1010 and / or antioxidant 1035, antioxidant 1024, antioxidant DLTP, still further, the mass ratio of the antioxidant 1010 and / or antioxidant 1035, the antioxidant DLTP, the antioxidant 1024 is 1:0.4-0.6:0.15-0.35; and / or, The silane coupling agent is silane 172; and / or, the lubricant contains silicone and / or PE wax.

8. A method of producing the irradiation-crosslinked insulating material according to any one of claims 1 to 7, characterized by, The preparation method comprises: weighing each raw material according to the formula, mixing and uniformly mixing, and extruding and granulating.

9. Use of the irradiation crosslinked insulating material according to any one of claims 1-7 in the preparation of an insulating material for automobile wire.

10. Use according to claim 9, characterized in that, The cross-sectional area of the automobile wire is less than or equal to 0.5 mm 2 .

Images