B1-grade ultraviolet irradiation cross-linked polyolefin insulating material and preparation method thereof

Abstract

The invention discloses a B1-grade ultraviolet irradiation cross-linked polyolefin insulating material and a preparation method thereof. The insulating material is prepared from the following raw materials in parts by weight: 15 to 30 parts of an ethylene-vinyl acetate copolymer, 10 to 20 parts of an ethylene-octene copolymer, 5 to 10 parts of low-density polyethylene, 5 to 15 parts of a polyolefin compatilizer, 100 to 120 parts of a flame retardant, 20 to 40 parts of a flame-retardant synergist, 2 to 5 parts of a lubricant, 1 to 3 parts of a photoinitiator, 1 to 3 parts of a cross-linking agent and 0.5 to 1.5 parts of a composite antioxidant. By optimizing the formula, the cross-linking efficiency is ensured, the stability of the flame retardant property and the processability is balanced, and the B1 grade requirement of the GB31247-2014 standard can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable materials, in particular to a B1 grade ultraviolet irradiation cross-linked polyolefin insulation material and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the power industry and the increasing demand for fire safety, there is an increasing demand for cable materials with high flame retardant properties. B1 flame retardant grade is a higher standard for cable flame retardant performance internationally, which requires the cable to have low smoke, halogen-free, low toxicity and excellent flame spread inhibition ability when burning.

[0003] Polyolefin materials are widely used in the field of cable materials due to their excellent electrical insulation performance, processing performance and physical and mechanical properties. The heat resistance, weather resistance and mechanical properties of polyolefin can be further improved by ultraviolet irradiation cross-linking technology. However, the existing ultraviolet irradiation cross-linked polyolefin insulation cable material is difficult to meet the B1 flame retardant grade requirement in terms of flame retardant performance. The main reason is that the compatibility of the traditional flame retardant system with the polyolefin matrix is poor, which reduces the processing performance and physical and mechanical properties of the material; and when the addition amount of the flame retardant is high, it will cause the extrusion performance of the cable material to be poor, the surface quality to be poor, and the ultraviolet irradiation cross-linking effect to be affected. Therefore, it is of great significance to develop an ultraviolet irradiation cross-linked polyolefin insulation cable material that meets the B1 flame retardant grade and has good processing performance and comprehensive performance. SUMMARY

[0004] The present application aims to overcome the defects in the prior art that the ultraviolet irradiation cross-linked polyolefin insulation cable material cannot simultaneously meet the B1 flame retardant grade, good processing performance and comprehensive performance, and provides a B1 flame retardant grade ultraviolet irradiation cross-linked low smoke halogen-free flame retardant polyolefin insulation material and a preparation method thereof.

[0005] The present application adopts the following technical solutions:

[0006] A B1 grade ultraviolet irradiation cross-linked polyolefin insulation material, characterized by being prepared from the following raw materials by weight:

[0007]

[0008] Among them, the flame retardant is a compound system of modified magnesium hydroxide and aluminum hydroxide, and the flame retardant synergist is one or more of melamine cyanurate, piperazine pyrophosphate, antimony oxide, zinc borate in any proportion.

[0009] Preferably, the mass ratio of modified magnesium hydroxide to aluminum hydroxide in the flame retardant is (60-85):(25-40).

[0010] Preferably, the VA content of the ethylene-vinyl acetate copolymer is 20%-33%.

[0011] More preferably, the ethylene-vinyl acetate copolymer is ethylene-vinyl acetate copolymer with VA content of 28%-33% alone or compounded with ethylene-vinyl acetate copolymer with VA content of 20%-28% in any ratio.

[0012] Preferably, the polyolefin compatibilizer is a combination of maleic anhydride grafted polyolefin elastomer and ethylene-vinyl acetate in any ratio.

[0013] Preferably, the lubricant is a combination of silicone masterbatch, polyethylene wax, zinc stearate, microcrystalline wax in any ratio.

[0014] More preferably, the lubricant is a combination of silicone masterbatch and polyethylene wax in a mass ratio of (3-5):1.

[0015] Preferably, the photoinitiator is a combination of benzpinacol, trimethylolpropane triacrylate, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide in any ratio.

[0016] Preferably, the crosslinking agent is a combination of vinyl trimethoxysilane, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, tripropylene glycol diacrylate in any ratio.

[0017] Preferably, the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1:1:1.

[0018] Preferably, the low-density polyethylene has a melt index of 0.1-1 g / 10 min at 190℃ under a load of 2.16 kg.

[0019] The application also provides a preparation method of B1-grade ultraviolet light irradiation crosslinked polyolefin insulation material, comprising the following steps:

[0020] S1, all raw materials are added to a mixing device and melt-mixed at 150-170℃ for 15-20 minutes;

[0021] S2, the mixed material is extruded and granulated by a single-screw extruder to obtain insulation material granules, and the extrusion temperature is controlled in the following zones: 120-130℃ in zone I, 130-140℃ in zone II, 140-150℃ in zone III, 150-160℃ in zone IV and 150-160℃ in the die head zone.

[0022] Preferably, the step further comprises:

[0023] S3, molding the granules into an insulation layer by an extruder, and irradiating the insulation layer by ultraviolet light at an intensity of 100-150 mW / cm 2 The crosslinking is completed by irradiating for 10-15 seconds.

[0024] Compared with the prior art, the technical scheme has the following advantages:

[0025] A. Meet B1 flame retardant grade: the present application uses specific proportion of flame retardant and flame retardant synergist, modified magnesium hydroxide and aluminum hydroxide decompose and release water vapor under heat, and the flame retardant synergist such as melamine cyanurate can synergistically act to form a high-efficiency flame-retardant system, so that the cable material passes the B1 bundle burning test, and has the characteristics of low smoke, halogen-free and low toxicity, which can effectively inhibit the spread of fire and reduce the release of smoke and toxic gas.

[0026] B. Good processing performance: the present application improves the compatibility of polyolefin resin and flame retardant by adding ethylene-vinyl acetate copolymer and polyolefin compatibilizer; the reasonable collocation of lubricants reduces the processing viscosity of the material, so that the cable material has good fluidity in the extrusion process, and the surface of the extruded insulation layer is smooth without flow marks and bubbles.

[0027] C. Excellent comprehensive performance: the ultraviolet light crosslinking agent and photoinitiator in the present application cooperate to form a stable crosslinking network under ultraviolet light irradiation, which improves the heat resistance, weather resistance and mechanical properties of the cable material; the composite antioxidant effectively inhibits the oxidative degradation of the material during processing and use, prolonging the service life of the cable; at the same time, the cable material has excellent electrical insulation performance, meeting the requirements of cable use. DETAILED DESCRIPTION

[0028] The present application can be implemented in many different forms, and should not be understood as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0029] Example 1

[0030] The present embodiment provides a B1 grade ultraviolet light irradiation crosslinked polyolefin insulation material, which is prepared by compounding the following raw materials in parts by weight:

[0031]

[0032]

[0033] The flame-retardant synergist is melamine cyanurate, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, the crosslinking agent is vinyl trimethoxysilane, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:1:1:1.

[0034] The preparation method is as follows:

[0035] S1, all the raw materials are added into a mixing device, and melted and mixed at 160℃ for 15 minutes;

[0036] S2, the mixed material is extruded and granulated through a single screw extruder to obtain insulation material granules, and the extrusion temperature is controlled in the following zones: 120-130℃ in zone I, 130-140℃ in zone II, 140-150℃ in zone III, 150-160℃ in zone IV, and 150-160℃ in the die head zone.

[0037] The granules are molded into an insulation layer through a φ70 extruder, and crosslinked under ultraviolet light irradiation at an intensity of 100mW / cm 2 for 10 seconds.

[0038] Example 2

[0039] The present embodiment provides a B1 grade ultraviolet light irradiation crosslinked polyolefin insulation material, which is prepared from the following raw materials in a weight ratio:

[0040]

[0041]

[0042] The flame-retardant synergist is antimony oxide, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, the crosslinking agent is pentaerythritol tetraacrylate, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:1:1:1.

[0043] The preparation method of Example 2 is the same as that of Example 1.

[0044] The granules are molded into an insulation layer through a φ70 extruder, and crosslinked under ultraviolet light irradiation at an intensity of 120mW / cm 2 for 10 seconds.

[0045] Example 3

[0046] The embodiment provides a B1 grade ultraviolet irradiation crosslinking polyolefin insulating material which is prepared from the following raw materials in parts by weight:

[0047]

[0048]

[0049] In the parts by weight components, the flame-retardant synergist is piperazine pyrophosphate, the photoinitiator is trimethylolpropane triacrylate, the crosslinking agent is vinyl trimethoxysilane, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:1:1:1.

[0050] The preparation method of the embodiment 3 is the same as that of the embodiment 1.

[0051] The granules are molded into an insulating layer through a φ70 extruder, and crosslinking is completed under ultraviolet irradiation at an intensity of 140 mW / cm 2 The irradiation is performed for 10 seconds.

[0052] Example 4

[0053] The embodiment provides a B1 grade ultraviolet irradiation crosslinking polyolefin insulating material which is prepared from the following raw materials in parts by weight:

[0054]

[0055]

[0056] In the parts by weight components, the flame-retardant synergist is piperazine pyrophosphate, the photoinitiator is trimethylolpropane triacrylate, the crosslinking agent is vinyl trimethoxysilane, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:1:1:1.

[0057] The preparation method of the embodiment 4 is the same as that of the embodiment 1.

[0058] The granules are molded into an insulating layer through a φ70 extruder, and crosslinking is completed under ultraviolet irradiation at an intensity of 140 mW / cm 2 The irradiation is performed for 10 seconds.

[0059] Comparative Example 1

[0060] The counter example provides an insulating material, which is prepared from the following raw materials in parts by weight:

[0061]

[0062]

[0063] In the above weight parts components, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, the crosslinking agent is vinyl trimethoxysilane, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1:1:1.

[0064] The preparation method and photo-crosslinking of Comparative Example 1 are the same as those of Example 1.

[0065] Comparative Example 2

[0066] The counter example provides an insulating material, which is prepared from the following raw materials in parts by weight:

[0067]

[0068] In the above weight parts components, the flame-retardant synergist is antimony oxide, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, the crosslinking agent is pentaerythritol tetraacrylate, and the composite antioxidant is a combination of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, dilauryl thiodipropionate, tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1:1:1.

[0069] The preparation method and photo-crosslinking of Comparative Example 2 are the same as those of Example 1.

[0070] Performance tests are conducted on Examples 1-4 and Comparative Examples 1-2, and the test results are as follows:

[0071]

[0072] It can be known from the test results that the cable materials prepared in Examples 1-4 of the present application all meet the B1 flame-retardant grade requirements and have good mechanical properties, electrical insulation properties, and aging resistance. Comparative Example 1 does not have sufficient flame-retardant properties due to the absence of a flame-retardant synergist, and cannot meet the B1 combustion standard. Comparative Example 2 has a significantly decreased flame-retardant property due to the absence of modified magnesium hydroxide, and lacks the synergistic effect of the composite flame retardant and the flame-retardant synergist, and thus cannot achieve the B1 flame-retardant grade.

[0073] The application is applicable to the prior art.

[0074] Obviously, the above-mentioned embodiments are only examples for clearly illustrating the present application, but not limitation on the embodiments. Based on the above-mentioned description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived from the present application are still within the protection scope of the present application.

Claims

1. A B1 grade ultraviolet radiation cross-linked polyolefin insulation material, characterized in that: It is prepared from the following raw materials in parts by weight: The flame retardant is a compound system of modified magnesium hydroxide and aluminum hydroxide, and the flame retardant synergist is one or more of melamine cyanurate, piperazine pyrophosphate, antimony oxide, and zinc borate.

2. The insulating material according to claim 1, characterized in that The mass ratio of modified magnesium hydroxide to aluminum hydroxide in the flame retardant is (60-85):(25-40).

3. The insulating material according to claim 1, characterized in that The VA content of the ethylene-vinyl acetate copolymer is 20%-33%.

4. The insulating material according to claim 1, characterized in that The polyolefin compatibilizer is one or both of maleic anhydride grafted polyolefin elastomer and ethylene vinyl acetate.

5. The insulating material according to claim 1, characterized in that The lubricant is one or more of silicone masterbatch, polyethylene wax, zinc stearate, and microcrystalline wax, and the mass ratio of silicone masterbatch to polyethylene wax is (3-5):

1.

6. The insulating material according to claim 1, characterized in that The photoinitiator is one or more of benzoin dimethyl ether, trimethylolpropane triacrylate, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; The crosslinking agent is one or more of vinyl trimethoxysilane, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and tripropylene glycol diacrylate.

7. The insulating material according to claim 1, characterized in that The composite antioxidant consists of N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, dilaurylthiodipropionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite.

8. The insulating material according to claim 1, characterized in that The low-density polyethylene has a melt index of 0.1-1 g / 10 min at 190° C. and 2.16 kg.

9. A method for preparing the B1-level ultraviolet-irradiation cross-linked polyolefin insulation material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Add all raw materials into a mixing device and melt mix at 150-170°C for 15-20 minutes; S2. The mixed material is extruded and granulated through a single screw extruder to obtain insulating material pellets. The extrusion temperature is controlled in zones: zone I 120-130°C, zone II 130-140°C, zone III 140-150°C, zone IV 150-160°C, and die head zone 150-160°C.

10. The preparation method according to claim 9, characterized in that The steps also include: S3, the pellets are formed into an insulating layer through an extruder, and irradiated with ultraviolet light at an intensity of 100-150mW / cm 2 Irradiate for 10-15 seconds to complete crosslinking.

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