Ultraviolet light crosslinking low smoke halogen-free insulating material and preparation method and application thereof

Abstract

This invention discloses an ultraviolet-crosslinked low-smoke halogen-free insulating material. By weight, the ultraviolet-crosslinked low-smoke halogen-free insulating material comprises the following components: 15-30 parts polyethylene, 10-25 parts polyolefin elastomer, 40-60 parts inorganic filler powder, 2-6 parts photoinitiator, and 1-3 parts co-crosslinking agent; the photoinitiator is selected from one or two of diaryliodomonium salt and triaryliodomonium salt; the co-crosslinking agent is dipentaerythritol hexaacrylate. The ultraviolet-crosslinked low-smoke halogen-free insulating material not only has good tensile strength and elongation at break, but also exhibits small changes in tensile strength and elongation at break after 720 hours of aging, demonstrating good aging resistance.

Description

Technical Field

[0001] This invention belongs to the technical field of wire and cable materials, and more specifically, relates to an ultraviolet cross-linked low-smoke halogen-free insulating material, its preparation method, and its application. Background Technology

[0002] Cross-linked cables have excellent high temperature resistance, higher long-term operating temperature, and longer service life. In existing technologies, radiation cross-linking is often used to prepare halogen-free insulation materials. The prepared halogen-free insulation materials are mainly used in home decoration wiring, fire protection wiring, etc. Due to their characteristics of low smoke, halogen-free, and low toxicity, their usage is increasing and gradually replacing traditional PVC materials.

[0003] Currently, cross-linking methods for cross-linked cables include electron beam irradiation and ultraviolet (UV) irradiation. Traditional halogen-free insulation materials, such as high-temperature resistant, low-smoke halogen-free cable materials (105-150℃), primarily utilize electron beam irradiation cross-linking technology. With the help of cross-linking agents like TAIC and TMPTMA, the polymer chains achieve bridging, forming a network structure and improving the material's temperature resistance. However, this method requires irradiation using specialized equipment after extrusion into finished cables. This equipment is expensive, requires a large area, and poses potential health hazards. In contrast, UV irradiation allows for direct online cross-linking during the cable extrusion process, enabling the production of cross-linked cables.

[0004] Patent publication number CN109485974A discloses an ultraviolet-irradiated cross-linked polyethylene insulation material, comprising 80-120 parts of polyethylene resin, 1-2 parts of benzophenone, 0.1-0.5 parts of dimethyl benzoate, 0.5-1.5 parts of triallyl isocyanate, 0.2-0.7 parts of trimethylolpropane triacrylate, 0.1-0.3 parts of ultraviolet absorber, 0.5-1.5 parts of antioxidant, and 0.5-1 parts of lubricant, which exhibits good cross-linking effect. However, cross-linked cables are commonly used in electrical internal wiring, home wiring, and other applications requiring long-term power transmission, placing high demands on the aging resistance of the material. Therefore, how to further improve the aging resistance of ultraviolet-irradiated cross-linked polyethylene insulation material has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, the primary objective of this invention is to provide an ultraviolet-crosslinked low-smoke halogen-free insulating material. This ultraviolet-crosslinked low-smoke halogen-free insulating material not only possesses good tensile strength and elongation at break, but also exhibits relatively small changes in tensile strength and elongation at break after 720 hours of aging, demonstrating excellent aging resistance.

[0006] The second objective of this invention is to provide a method for preparing a UV-crosslinked low-smoke halogen-free insulating material.

[0007] The third objective of this invention is to provide an application of ultraviolet-crosslinked low-smoke halogen-free insulating material in the preparation of wires and cables.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0009] An ultraviolet crosslinked low-smoke halogen-free insulating material, comprising the following components by weight: 15-30 parts of polyethylene, 10-25 parts of polyolefin elastomer, 40-60 parts of inorganic filler powder, 2-6 parts of photoinitiator, and 1-3 parts of co-crosslinking agent.

[0010] The photoinitiator is selected from one or two of diaryliodomonium salts and triaryliodomonium salts;

[0011] The crosslinking agent is dipentaerythritol hexaacrylate.

[0012] This invention uses diaryliodomonium salt and triaryliodomonium salt as photoinitiators, combined with a specific co-crosslinking agent, dipentaerythritol hexaacrylate. The inventors discovered through research that the combination of the above-mentioned photoinitiator and co-crosslinking agent has higher crosslinking efficiency, and there is no residue in the polyethylene system after ultraviolet light initiation. This avoids the situation in subsequent practical applications where the residual initiator and co-crosslinking agent are further over-crosslinked due to continuous high temperature, resulting in a sharp decrease in tensile strength and elongation at break after aging.

[0013] This invention utilizes diaryliodomonium salt and triaryliodomonium salt as photoinitiators, combined with a specific co-crosslinking agent, dipentaerythritol hexaacrylate, to prepare a UV-crosslinked low-smoke halogen-free insulating material that not only has good tensile strength and elongation at break, but also exhibits relatively small changes in tensile strength and elongation at break after aging for 720 hours, demonstrating good aging resistance.

[0014] Specifically, in the ultraviolet cross-linked low-smoke halogen-free insulating material, the content of polyethylene is not less than 13.7%.

[0015] Specifically, the amount of polyethylene used can be 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, etc., or any range formed by the above values, such as 17-23 parts, 19-27 parts, etc., and the present invention is not limited thereto. Specifically, the amount of polyolefin elastomer used can be 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, etc., or any range formed by the above values, such as 12-18 parts, 14-22 parts, etc., and the present invention is not limited thereto. Specifically, the amount of inorganic filler powder used can be 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, etc., or any range formed by the above values, such as 44-50 parts, 48-56 parts, etc., and the present invention is not limited thereto.

[0016] Preferably, the diaryliodomonium salt is selected from one or more of 4,4′-diacetamidodiphenyliodohexafluorophosphate, 3,3′-dinitrodiphenyliodohexafluorophosphate, and diphenyliodohexafluorophosphate; and / or

[0017] The triaryliodomonium salt is selected from one or more of triphenylthiohexafluorophosphate, triphenylthiohexafluoroantimonate, and 4-tolyldiphenylthiohexafluorophosphate.

[0018] Preferably, the D50 particle size of the inorganic filler powder is 0.1-5 μm. More preferably, the D50 particle size of the inorganic filler powder is 0.5-1.5 μm. Specifically, the D50 particle size of the inorganic filler powder in this invention can be 0.3 μm, 0.7 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, etc., or any range formed by the above values, such as 1-3 μm, 2-4 μm, etc., and this invention is not limited thereto. More specifically, the method for testing the D50 particle size of the inorganic filler powder is as follows: using deionized water as a dispersant, the powder is fully dispersed in the aqueous solution by ultrasound, and then the particle size distribution is tested using a Malvern particle size analyzer.

[0019] Preferably, the inorganic filler powder is selected from one or more of magnesium hydroxide and aluminum hydroxide.

[0020] Preferably, the melt flow index of the polyethylene under test conditions of 190℃ and 2.16Kg is 0.2-6g / 10min. The test method for the melt flow index of the polyethylene is GB-T3682-2000. More specifically, the melt flow index of the polyethylene under test conditions of 190℃ and 2.16Kg is 0.27-6g / 10min. More specifically, the melt flow index of the polyethylene can be 0.5g / 10min, 1.0g / 10min, 1.5g / 10min, 2.0g / 10min, 2.5g / 10min, 3.0g / 10min, 3.5g / 10min, 4.0g / 10min, 4.5g / 10min, 5.0g / 10min, 5.5g / 10min, etc., or any range formed by the above values, such as 1.5-3.0g / 10min, 2.0-4.0g / 10min, etc., and the present invention is not limited thereto.

[0021] Preferably, the melt index of the polyolefin elastomer under test conditions of 190℃ and 2.16Kg is 0.5-10g / 10min. More preferably, the melt index of the polyolefin elastomer under test conditions of 190℃ and 2.16Kg is 0.8-2g / 10min. The test method for the melt index of the polyolefin elastomer is GB-T3682-2000. More specifically, the melt index of the polyolefin elastomer can be 1.5g / 10min, 3.5g / 10min, 5.5g / 10min, 7.5g / 10min, 9.5g / 10min, etc., or any range formed by the above values, such as 1.5-5.5g / 10min, 7.5-9.5g / 10min, etc., and the present invention is not limited thereto.

[0022] Preferably, the polyolefin elastomer is selected from one or more of EVA and POE.

[0023] Preferably, the UV crosslinked low-smoke halogen-free insulating material further comprises 3-6 parts by weight of antioxidant. Specifically, the antioxidant includes a primary antioxidant and / or a secondary antioxidant; the primary antioxidant is selected from hindered phenolic antioxidants, and the secondary antioxidant is selected from hindered amine antioxidants or phosphite antioxidants. The primary antioxidant includes, but is not limited to, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octacarbonyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, etc. The secondary antioxidant is selected from one or more of diphenylamine-substituted derivatives (such as antioxidant 445), tris[2,4-di-tert-butylphenyl]phosphite, and 2,2'-thionylethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0024] Furthermore, this invention claims protection for a method for preparing an ultraviolet cross-linked low-smoke halogen-free insulating material, wherein the components are mixed evenly, kneaded, plasticized and granulated to obtain the ultraviolet cross-linked low-smoke halogen-free insulating material.

[0025] Preferably, the mixing is carried out at 100-200°C.

[0026] Furthermore, this invention also claims protection for the application of an ultraviolet-crosslinked low-smoke halogen-free insulating material in the manufacture of wires and cables. The wires and cables can be used as internal wiring in electrical appliances, electrical wiring in home decoration, fire protection wiring, etc.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention provides an ultraviolet-crosslinked low-smoke halogen-free insulating material, which uses diaryliodomonium salt and triaryliodomonium salt as photoinitiators, and combines them with a specific co-crosslinking agent, dipentaerythritol hexaacrylate. This results in an ultraviolet-crosslinked low-smoke halogen-free insulating material that not only has good tensile strength and elongation at break, but also exhibits small changes in tensile strength and elongation at break after aging for 720 hours, demonstrating good aging resistance. Detailed Implementation

[0029] The present invention will be further described below with reference to the specification and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0030] The raw materials for the examples and comparative examples are as follows:

[0031] Polyethylene 1: Melt index of 6 g / 10 min under test conditions of 190℃ and 2.16 kg, LLDPE 0630H, Sinopec;

[0032] Polyethylene 2: Melt index of 0.27 g / 10 min under test conditions of 190℃ and 2.16 kg, ENABLE2203MC, ExxonMobil;

[0033] Polyolefin elastomer: POE, melt index 1 g / 10 min under test conditions of 190℃ and 2.16 kg, POE 5017, Wanhua Chemical;

[0034] Inorganic filler powder: aluminum hydroxide, D50 particle size 1.2μm, OL-104LEO, Qiu Bo;

[0035] Photoinitiator 1: Diphenyliodohexafluorophosphate, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0036] Photoinitiator 2: Triphenylthiohexafluoroantimonate, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0037] Photoinitiator 3: Benzophenone, Dongguan Hengqiao;

[0038] Co-crosslinking agent 1: Dipentaerythritol hexaacrylate, DPHA, Miwon;

[0039] Crosslinking agent 2: Trimethylolpropane acrylate, TMPTA, Dongguan Hengqiao;

[0040] Antioxidant, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], antioxidant 1010, commercially available.

[0041] Unless otherwise specified, all components (such as antioxidants) used in the parallel examples and comparative examples are the same commercially available products.

[0042] Example 1

[0043] The weight proportions of the raw materials used in Example 1 are shown in Table 1.

[0044] A UV-crosslinked low-smoke halogen-free insulating material, the specific steps of which include:

[0045] Polyethylene, polyolefin elastomer, inorganic filler powder, antioxidant, photoinitiator and crosslinking agent are mixed evenly and then kneaded at 170°C using a reciprocating machine, followed by plasticizing and granulation to obtain a UV crosslinked low-smoke halogen-free insulating material.

[0046] Examples 2-9

[0047] The weight proportions of the raw materials used in the following embodiments are shown in Table 1.

[0048] The specific preparation steps for the following embodiments are the same as those for Embodiment 1.

[0049] Comparative Examples 1-5

[0050] The weight proportions of raw materials used in each of the following comparative examples are shown in Table 2.

[0051] The specific preparation steps for the other comparative examples are the same as those in Example 1.

[0052] Table 1

[0053]

[0054] Table 2 shows the formulation components for each comparative example:

[0055] Table 2

[0056] Components Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polyethylene 1 15 15 15 15 15 Polyolefin elastomers 20 20 20 20 20 Inorganic filler powder 55 55 55 55 55 Photoinitiator 1 / / 8 2 2 Photoinitiator 3 2 4 / / / Crosslinking agent 1 1 1 1 / 5 Crosslinking agent 2 / / / 1 / antioxidants 4 4 4 4 4

[0057] The ultraviolet-crosslinked low-smoke halogen-free insulating materials prepared in the above embodiments and comparative examples were crosslinked by ultraviolet irradiation (irradiation power set to 60% to 100%), and then tested using the following method.

[0058] (1) Tensile strength and elongation at break: The tensile strength and elongation at break of UV cross-linked low-smoke halogen-free insulating materials before and after high-temperature aging were tested according to standard GB / T 1040.3-2006. Type 5 dumbbell-shaped specimens were used, with h = 1 mm and L3 = 115 mm.

[0059] (2) Artificial climate aging test: The test was performed according to Cycle 4 of the ISO 4892-2 2013 test standard, with an irradiance of 0.51 W / m. 2 *nm.

[0060] (3) Test method for elongation performance: Tested according to GB / T 2951.21-2008 standard. Among them, the thermal elongation rate ≤175% is considered to meet the requirements.

[0061] Table 3

[0062]

[0063] Table 4

[0064]

[0065] As shown in Table 3 above, the UV-crosslinked low-smoke halogen-free insulating material prepared by this invention not only has good thermal elongation, initial tensile strength, and elongation at break, but also maintains excellent tensile strength and elongation at break after 720 hours of artificial climate aging. More specifically, the initial tensile strength of the prepared UV-crosslinked low-smoke halogen-free insulating material is ≥14.5 MPa, and the initial elongation at break is ≥237%; after 720 hours of artificial climate aging, the change rate of tensile strength is ≤25%, and the change rate of elongation at break (absolute value) is ≤26%.

[0066] As can be seen from Examples 1, 2, 1, 2, and 4, the technical effects of this invention can only be achieved when diarylioiodonium salts, triarylioiodonium salts, and the co-crosslinking agent dipentaerythritol hexaacrylate are used in combination. When conventional photoinitiators (such as benzophenone) or conventional co-crosslinking agents (trimethylolpropane acrylate) are used, the changes in tensile strength and elongation at break (absolute values) are relatively large, indicating poor aging resistance and making it difficult to achieve the technical effects of this invention.

[0067] As can be seen from Examples 1, 3, and 5, when there is a large amount of photoinitiator or co-crosslinking agent in the system, it is easy for it to remain in the UV-crosslinked low-smoke halogen-free insulating material and further crosslink during the subsequent aging process, which in turn makes the change rate of tensile strength and the change rate of elongation at break (absolute value) larger and the aging resistance poor.

[0068] The foregoing examples are merely illustrative, used to explain some features of the method described in this invention. The appended claims are intended to claim the broadest possible scope, and the embodiments presented herein are demonstrated by the applicant's actual experimental results. Therefore, the applicant intends that the appended claims are not limited by the selection of examples illustrating the features of the invention. Some numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. An ultraviolet light cross-linked low smoke, halogen-free insulation material, characterized in that, By weight, it includes the following components: 15-30 parts of polyethylene, 10-25 parts of polyolefin elastomer, 40-60 parts of inorganic filler powder, 2-6 parts of photoinitiator, and 1-3 parts of co-crosslinking agent. The photoinitiator is selected from one or two of diaryliodomonium salts and triaryliodomonium salts; The crosslinking agent is dipentaerythritol hexaacrylate.

2. The ultraviolet-crosslinked low-smoke halogen-free insulating material according to claim 1, characterized in that, The diaryliodomonium salt is selected from one or more of 4,4′-diacetamidodiphenyliodohexafluorophosphate, 3,3′-dinitrodiphenyliodohexafluorophosphate, and diphenyliodohexafluorophosphate; and / or The triaryliodomonium salt is selected from one or more of triphenylthiohexafluorophosphate, triphenylthiohexafluoroantimonate, and 4-tolyldiphenylthiohexafluorophosphate.

3. The UV cross-linking low smoke and zero halogen insulation material according to claim 1, characterized in that, The D50 particle size of the inorganic filler powder is 0.1-5μm.

4. The UV crosslinking low smoke halogen-free insulation material according to claim 1, characterized in that, The inorganic filler powder is selected from one or two of magnesium hydroxide and aluminum hydroxide.

5. The UV crosslinking low smoke halogen-free insulation material according to claim 1, characterized in that, The melt flow index of the polyethylene under test conditions of 190℃ and 2.16Kg is 0.2-6g / 10min.

6. The UV crosslinking low smoke halogen-free insulation material according to claim 1, characterized in that, The melt index of the polyolefin elastomer under test conditions of 190℃ and 2.16Kg is 0.5-10g / 10min.

7. The UV crosslinking low smoke halogen-free insulation material according to claim 1, characterized in that, The polyolefin elastomer is selected from one or both of EVA and POE.

8. The UV crosslinking low smoke halogen-free insulation material according to claim 1, characterized in that, It also includes 3-6 parts by weight of antioxidants.

9. A process for the preparation of the UV-crosslinking low smoke halogen-free insulation material according to any one of claims 1 to 8, characterized in that, The components are mixed evenly, kneaded, plasticized and granulated to obtain a UV crosslinked low-smoke halogen-free insulating material.

10. The use of the ultraviolet cross-linked low-smoke halogen-free insulating material according to any one of claims 1-8 in the preparation of wires and cables.

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