All-black type silane crosslinking overhead insulation material and preparation method thereof

Abstract

The invention provides an all-black type silane crosslinking overhead insulation material and a preparation method thereof.The all-black type silane crosslinking overhead insulation material comprises a component A and a component B. The component A comprises linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, a coupling agent, an initiator, a water absorbent, an antioxidant and carbon black master batch, and the component B comprises linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, a coupling agent, an initiator, a water absorbent, an antioxidant and carbon black master batch. 2, the linear low-density polyethylene resin, the catalyst, the antioxidant and the rheological master batch. The modified carbon black master batch provided by the invention is subjected to twin-screw mixing, so that the dispersion effect of the carbon black is further improved, and after a produced cable insulation layer is sliced, the phenomenon of insulation transparency does not exist. The carbon black content is 0.5%-1%, and due to the fact that the carbon black content is not high and laser lettering is obvious, the produced cable does not have the problems of laser printing and unclear lettering, the insulation surface of the material is smooth, the thermal aging resistance and the weather aging resistance are excellent, and the standard requirement is met.

Description

Technical Field

[0001] This invention belongs to the field of wire and cable technology, and relates to overhead insulation materials for cables, and more particularly to an all-black silane cross-linked overhead insulation material with excellent carbon black dispersion, excellent thermal aging and weather aging resistance, and its preparation method. Background Technology

[0002] With the booming development of the overhead power line industry and increased market demand, many cable manufacturers have introduced high-speed machines. However, due to the high cable feeding speed, these machines often lack sufficient material mixing capacity during production, resulting in poor carbon black dispersion and causing insulation transparency issues after cable insulation layers are sliced. Some manufacturers address this transparency problem by increasing the carbon black content, but this introduces another problem: since most manufacturers currently use laser printing, the carbon black content should be maintained at 0.5%-1%. Increasing the carbon black content can lead to unclear printing on the cable surface. Furthermore, with the global expansion of the applicant company's products, some countries, such as Australia and Europe, have specific requirements for carbon black dispersion, which existing materials on the market cannot meet.

[0003] Chinese Patent Publication No. CN116262845A, published on June 16, 2023, entitled "An Invention Patent for a Carbon Black-Resistant, Tracking-Resistant Silane Crosslinked Polyethylene Insulation Material and Its Preparation Method There is a carbon black content of more than 3% in the material prepared in this patent. Due to the high carbon black content, the printed characters on the produced cables are unclear, so the problem cannot be solved at its root.

[0004] Chinese Patent Publication No. CN120535863A, published on August 26, 2025, is an invention patent entitled "A Silane Crosslinked Polyethylene Overhead Cable Material for Laser Engraving and Its Preparation Method." This patent mainly adds nanofillers and laser engraving black masterbatch to the B material, so that the carbon blackness of the prepared silane crosslinked polyethylene overhead cable is not affected by the carbon black content during laser engraving. However, the addition of nanofillers significantly increases the material cost, making the price unacceptable to customers. Furthermore, because the nanofillers and laser engraving black masterbatch contain other components, the volume resistivity is lower than that of conventional materials. In actual production and use, small molecule substances are more likely to be generated at the die opening, resulting in more precipitates at the die opening. Moreover, the addition of black masterbatch to the B material does not solve the problem of insufficient material mixing capacity during production and use, resulting in poor carbon black dispersion and causing insulation transparency problems after the cable insulation layer is sliced. Summary of the Invention

[0005] To address the shortcomings of existing materials, such as insufficient carbon black dispersion, unclear printing, high cost, precipitates at the die opening, and decreased volume resistivity, this invention provides a fully black silane cross-linked overhead insulating material. This invention improves the carbon black masterbatch preparation method and optimizes the base material ratio and production process to further improve carbon black dispersion, resulting in excellent carbon black dispersion with a carbon black content maintained at 0.5%-1%. Furthermore, its mechanical properties, conventional aging performance, and weather resistance meet requirements. This invention also enhances the lubrication effect between the material and the die opening by adding a certain proportion of rheology masterbatch, forming a lubricating film at the die opening and preventing the formation of precipitates.

[0006] Secondly, the present invention also provides a method for preparing the above-mentioned all-black silane cross-linked overhead insulating material.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a fully black silane cross-linked overhead insulating material, the fully black silane cross-linked overhead insulating material comprising component A and component B, wherein the mass ratio of component A to component B is 90-95:5-10, and component A comprises the following raw materials in parts by weight: 50-70 parts of linear low-density polyethylene resin 1, 10-30 parts of linear low-density polyethylene resin 2, 8-15 parts of polypropylene resin, 1-2 parts of coupling agent, 0.1-0.5 parts of initiator, 0.1-0.5 parts of water absorbent, 0.1-0.5 parts of antioxidant, and 2-5 parts of carbon black masterbatch; Component B comprises the following raw materials in parts by weight: 30-50 parts linear low-density polyethylene resin 1, 40-60 parts linear low-density polyethylene resin 2, 0.5-1 part catalyst, 2-10 parts antioxidant and 5-10 parts rheology masterbatch. The melt index of the linear low-density polyethylene resin 1 is 1-5 g / 10 min, and the melt index of the linear low-density polyethylene resin 2 is 15-25 g / 10 min.

[0008] In this technical solution, the all-black silane cross-linked overhead insulation material of the present invention uses low-density polyethylene as the main base material in component A, which has the advantages of high volume resistivity and low dielectric loss. At the same time, 8-15 parts of polypropylene resin are added to improve the insulation and anti-shrinkage performance of the material. If the addition ratio exceeds 15 parts, it will cause difficulties in plasticizing the material and cause surface bumps during use.

[0009] As a preferred embodiment of the present invention, the polypropylene resin is one or more of homopolymer PP or random copolymer PP, and the melt index of the polypropylene resin is 1-5 g / 10 min.

[0010] As a preferred embodiment of the present invention, the coupling agent is one or more of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri(2-dimethoxyethoxy)silane.

[0011] In a preferred embodiment of the present invention, the initiator is one or more of dicumyl peroxide and tert-butyl peroxide-2-ethylhexyl carbonate.

[0012] In a preferred embodiment of the present invention, the water-absorbing agent is an organosilazane.

[0013] In a preferred embodiment of the present invention, the antioxidant is one or more of pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, distearate thiodipropionate, tris(2,4-di-tert-butylphenyl)phosphite, 4,4'-thiobis(6-tert-butyl-3-methylphenol), and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine.

[0014] As a preferred embodiment of the present invention, the carbon black masterbatch is made by twin-screw extrusion granulation of 30-50 parts carbon black, 40-60 parts LLDPE with a melt index of 35-55 g / 10 min, and 5-15 parts polyethylene wax.

[0015] In this technical solution, carbon black masterbatch is mixed with other components using a twin-screw extruder. Due to the strong shearing and mixing capabilities of the twin-screw extruder, the dispersion effect of the carbon black is greatly improved. The carbon black masterbatch is prepared by twin-screw extrusion granulation of 30-50 parts carbon black, 40-60 parts LLDPE with a melt index of 35-55 g / 10 min, and 5-15 parts polyethylene wax. If LLDPE with a melt index lower than this range is used as a carrier, it will affect the dispersion of the carbon black. If LLDPE with a melt index higher than this range is used as a carrier, the carrier cost is high and impractical. Adding polyethylene wax further improves the dispersion of the carbon black.

[0016] As a preferred embodiment of the present invention, the rheology masterbatch is made by granulation of 10-30 parts of fluororubber, 60-80 parts of LLDPE, and 5-15 parts of zinc stearate through a mixer and a twin-screw extruder.

[0017] As a preferred embodiment of the present invention, the catalyst is one or a combination of two of dibutyltin dilaurate, dioctyltin dilaurate, and dodecylbenzenesulfonic acid.

[0018] Secondly, the present invention provides a method for preparing the above-mentioned all-black silane cross-linked overhead insulating material, the preparation method comprising the following steps: 1) The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried, mixed evenly, and added to a twin-screw extruder. The coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid and injected into the twin screw extruder for mixing and grafting reaction. After granulation by a cutter, cooling in a water tank, drying in a fluidized bed, and packaging, component A is obtained. 2) Component B is made by mixing linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, catalyst, antioxidant, and rheology masterbatch evenly, adding it to a twin-screw extruder, extruding, granulating, and drying to obtain component B. 3) Mix component A obtained in step 1) and component B obtained in step 2), and extrude the mixture through a single screw extruder. Then, perform water boiling or steam crosslinking to obtain the all-black silane crosslinked overhead insulation material.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention provides modified carbon black masterbatch, and further improves the dispersion effect of carbon black through twin-screw compounding, so that the produced cable insulation layer slices will not have the phenomenon of transparent insulation.

[0020] 2) The carbon black content of the material provided by this invention is 0.5%-1%. Because the carbon black content is not high, the laser printing is obvious, so the produced cable will not have the problem of unclear laser printing.

[0021] 3) The material provided by this invention has a smooth insulating surface and excellent thermal aging and weather aging resistance, meeting the standard requirements. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 This embodiment provides an all-black silane cross-linked overhead insulation material, which is composed of component A and component B in a mass ratio of 95:5. Each component is composed of the following parts by weight of raw materials.

[0024] Component A comprises 68 parts of linear low-density polyethylene resin 1 (Zhenhai, 7042, the same below) with a melt index of 1-5 g / 10 min (at 190℃ and 2.16 kg). 20 parts of linear low-density polyethylene resin 2 (Zhenhai, 2320, the same below) with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin (Zhongmei, PL5E89, the same below) with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0025] Component B includes 42 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0026] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black (model N330, the same below), 50 parts LLDPE (ExxonMobil, 6201, the same below) with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0027] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0028] This embodiment also provides a method for preparing an all-black silane cross-linked overhead insulating material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain a fully black silane crosslinked overhead insulation material.

[0029] Example 2 This embodiment provides an all-black silane cross-linked overhead insulation material, which is composed of component A and component B in a mass ratio of 95:5. Each component is composed of the following parts by weight of raw materials.

[0030] Component A comprises 66 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 22 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0031] Component B includes 41 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 51 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate, (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0032] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0033] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0034] This embodiment also provides a method for preparing an all-black silane cross-linked overhead insulating material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain a fully black silane crosslinked overhead insulation material.

[0035] Example 3 This embodiment provides an all-black silane cross-linked overhead insulation material, which is composed of component A and component B in a mass ratio of 95:5. Each component is composed of the following parts by weight of raw materials.

[0036] Component A comprises 63 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 25 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0037] Component B includes 45 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 47 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate, (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0038] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0039] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0040] This embodiment also provides a method for preparing an all-black silane cross-linked overhead insulating material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain a fully black silane crosslinked overhead insulation material.

[0041] Comparative Example 1 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0042] Component A comprises 56 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 25 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 17 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0043] Component B comprises 45.2 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 47 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 0.8 parts of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate, in a ratio of 1:1:1, and 5 parts of rheology masterbatch.

[0044] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0045] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0046] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0047] Comparative Example 2 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0048] Component A comprises 66 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 25 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 5 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0049] Component B comprises 44.8 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 47 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1.2 parts of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate, in a ratio of 1:1:1, and 5 parts of rheology masterbatch.

[0050] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0051] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0052] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0053] Comparative Example 3 This comparative example provides a high carbon black dispersion all-black silane crosslinked overhead insulation material, which is composed of component A and component B in a mass ratio of 85:15. Each component is composed of the following parts by weight of raw materials.

[0054] Component A comprises 68 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 20 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0055] Component B includes 42 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0056] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0057] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0058] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0059] Comparative Example 4 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0060] Component A comprises 68 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 20 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0061] Component B includes 42 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0062] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 30 parts LLDPE with a melt index of 1-5 g / 10 min, 20 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0063] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0064] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0065] Comparative Example 5 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0066] Component A comprises 63 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 20 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 7 parts of carbon black masterbatch.

[0067] Component B includes 42 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate thiodipropionate (compounded in a ratio of 1:1:1), and 5 parts of rheology masterbatch.

[0068] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0069] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0070] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0071] Comparative Example 6 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0072] Component A comprises 69 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 20 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 1 part of carbon black masterbatch.

[0073] Component B comprises 42 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, 2 parts of compounded antioxidants (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), distearate, in a ratio of 1:1:1, and 5 parts of rheology masterbatch.

[0074] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0075] The rheology masterbatch is made by granulation of 20 parts fluororubber, 70 parts LLDPE, and 10 parts zinc stearate using a mixer and a twin-screw extruder.

[0076] This comparative example also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0077] Comparative Example 7 This comparative example provides an overhead insulation material composed of component A and component B in a mass ratio of 95:5, with each component specifically consisting of the following parts by weight of raw materials.

[0078] Component A comprises 68 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 20 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 8 parts of homopolymer copolymerized polypropylene resin with a melt index of 1-5 g / 10 min, 1.2 parts of vinyltriethoxysilane, 0.2 parts of dicumyl peroxide, 0.3 parts of organosilazane, 0.3 parts of 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2 parts of carbon black masterbatch.

[0079] Component B includes 47 parts of linear low-density polyethylene resin 1 with a melt index of 1-5 g / 10 min, 50 parts of linear low-density polyethylene resin 2 with a melt index of 15-25 g / 10 min, 1 part of dibutyltin dilaurate, and 2 parts of compounded antioxidants, which are pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine), and distearate thiodipropionate (in a ratio of 1:1:1).

[0080] The carbon black masterbatch is made by twin-screw extrusion granulation of 40 parts carbon black, 50 parts LLDPE with a melt index of 35-55 g / 10 min, and 10 parts polyethylene wax.

[0081] This embodiment also provides a method for preparing overhead insulation material, which mainly includes the following steps: The linear low-density polyethylene resin 1, linear low-density polyethylene resin 2, polypropylene resin, and carbon black masterbatch of component A are dried in a drying silo and mixed evenly in proportion. The mixture is then added to a twin-screw extruder. At the same time, coupling agent, initiator, water absorbent, and antioxidant are prepared into a mixed liquid in proportion and injected into the twin-screw extruder in proportion for mixing and grafting reaction. The mixture is then granulated by a cutter, cooled in a water tank, dried in a fluidized bed, and packaged to obtain component A. The linear low-density polyethylene resin 1 and linear low-density polyethylene resin 2 of component B, catalyst, antioxidant, and rheology masterbatch are mixed in proportion, added to a twin-screw extruder, extruded, granulated, and dried to obtain component B. Mix components A and B in a certain proportion, extrude them using a single screw, and then crosslink them by boiling in water or steaming at 90-100℃ for 4 hours to obtain the overhead insulation material.

[0082] Performance testing The insulating materials prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to comprehensive performance tests, including appearance, heat shrinkage properties, mechanical properties, weather aging resistance, and insulation transparency after cross-section examination. The test methods and technical requirements are as follows: Appearance and performance: After production, check whether there are pre-crosslinked spots on the insulation surface, whether there is insulation transparency after insulation slicing, whether the laser printing is unclear, and whether there are exudates at the die opening. Heat shrinkage performance: tested according to GB / T2951.13-2008; Mechanical properties: tested according to GB / T1040.3-2006; Weathering resistance: tested according to GB 14049-2008; The specific results are shown in Table 1: Table 1. Performance Test Results As shown in Table 1, the silane cross-linked overhead insulation material prepared using the method of the present invention is superior to the industry standard requirements in terms of appearance, heat shrinkage, mechanical properties, and weather aging resistance.

[0083] Compared with Example 1, Comparative Example 1 added 17 parts of polypropylene resin. Because polypropylene has a higher melting point than polyethylene, it caused poor plasticization during extrusion, resulting in unplasticized lumps on the surface. Furthermore, the mechanical properties of the material decreased significantly after crosslinking, indicating that excessive addition of polypropylene resin affected both appearance and mechanical properties.

[0084] Compared with Example 1, Comparative Example 2 added 5 parts of polypropylene resin, and the heat shrinkage of the extruded cable was 5%, which did not meet the standard requirements. This indicates that the amount of polypropylene resin added was too small, which affected the heat shrinkage performance.

[0085] Compared with Example 1, the mass ratio of component A to component B in Comparative Example 3 was (85:15). When extruded, pre-crosslinked dots appeared on the surface. The use of excessive catalyst caused local pre-crosslinking phenomenon in the material, indicating that the appropriate mass ratio of component A to component B plays a significant role in the quality of the finished product.

[0086] Compared with Example 1, Comparative Example 4 added 30 parts of LLDPE with a melt index of 1-5 g / 10 min and 20 parts of LLDPE with a melt index of 35-55 g / 10 min to the carbon black masterbatch. When extruded, there was a problem with the insulation transparency after insulation cutting and the printing was unclear after laser printing. Because some low melt index substrates were used, the carbon black agglomeration was serious and the dispersion was insufficient. This shows that when producing carbon black masterbatch, an appropriate proportion of high melt index substrates should be used.

[0087] Compared with Example 1, the amount of carbon black masterbatch added in Comparative Example 5 was 7 parts. During extrusion production, there was a problem with unclear laser printing. Because of the high carbon black content, the laser energy was completely absorbed on the insulating surface, indicating that when the carbon black content is high, the laser printing is unclear.

[0088] Compared with Example 1, Comparative Example 6 had a carbon black masterbatch addition of 1 part. The produced material failed the weather aging test because the carbon black content was low and it could not effectively resist the damage of ultraviolet light. This shows that when the carbon black content is low, the material fails the weather aging test.

[0089] Compared to Example 1, Comparative Example 7 did not add rheology masterbatch. When the customer used the produced material, obvious precipitates were generated at the die opening. This was because the material was under pressure at the die opening during use, causing friction between the material and the mold, and small molecule precipitates were generated. However, the addition of rheology masterbatch formed a lubricating film at the die opening, preventing the generation of precipitates.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A full black type silane crosslinking aerial insulating material, characterized in that, The full black type silane crosslinking overhead insulation material comprises A component and B component, the mass ratio of the A component and the B component is 90-95:5-10, the A component comprises the following raw materials in parts by weight: 50-70 parts of linear low density polyethylene resin 1, 10-30 parts of linear low density polyethylene resin 2, 8-15 parts of polypropylene resin, 1-2 parts of coupling agent, 0.1-0.5 parts of initiator, 0.1-0.5 parts of water absorption agent, 0.1-0.5 parts of antioxidant and 2-5 parts of carbon black master batch; The B component comprises the following raw materials in parts by weight: 30-50 parts of linear low density polyethylene resin 1, 40-60 parts of linear low density polyethylene resin 2, 0.5-1 parts of catalyst, 2-10 parts of antioxidant and 5-10 parts of rheological master batch; The linear low density polyethylene resin 1 has a melt index of 1-5 g / 10 min, and the linear low density polyethylene resin 2 has a melt index of 15-25 g / 10 min.

2. A full black type silane crosslinking aerial insulating material according to claim 1, characterized in that, The polypropylene resin is one or more of homopolymer PP or random copolymer PP, and the polypropylene resin has a melt index of 1-5 g / 10 min.

3. A full black type silane crosslinking aerial insulating material according to claim 1, characterized in that, The coupling agent is one or more of vinyltriethoxysilane, vinyltrimethoxysilane and vinyltri(2-dimethoxyethoxy)silane.

4. A full black type silane crosslinking aerial insulating material according to claim 1, characterized in that, The initiator is one or more of dicumyl peroxide and tert-butyl peroxy-2-ethylhexyl carbonate.

5. A full black type silane crosslinking aerial insulating material according to claim 1, characterized in that, The water absorption agent is organosilazane.

6. A full black type silane crosslinking aerial insulating material according to claim 1, characterized in that, The antioxidant is one or more of pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, distearyl thiodipropionate, tris(2,4-di-tert-butylphenyl) phosphite, 4,4'-thiobis(6-tert-butyl-3-methylphenol) and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine.

7. A full black type silane crosslinking aerial insulating material according to claim 1, characterized by, The carbon black master batch is prepared by twin-screw extrusion granulation of 30-50 parts of carbon black, 40-60 parts of LLDPE with a melt index of 35-55 g / 10 min and 5-15 parts of polyethylene wax.

8. A full black type silane crosslinking aerial insulating material according to claim 1, characterized by, The rheological master batch is prepared by internal mixer and twin-screw extrusion granulation of 10-30 parts of fluoro rubber, 60-80 parts of LLDPE and 5-15 parts of zinc stearate.

9. A full black type silane crosslinking aerial insulating material according to claim 1, characterized by, The catalyst is one or a combination of two of dibutyl tin dilaurate, di-n-octyl tin dilaurate and dodecyl benzene sulfonic acid.

10. A process for the preparation of a full black type silane crosslinked aerial insulating mass according to any one of claims 1 to 9, characterized in that, The preparation method comprises the following steps: 1) The linear low density polyethylene resin 1, the linear low density polyethylene resin 2, the polypropylene resin, the carbon black master batch of the A component are dried and uniformly mixed, and then added into a twin-screw extruder; the coupling agent, the initiator, the water absorption agent and the antioxidant are prepared into a mixed liquid and injected into the twin-screw extruder to perform mixing and grafting reaction, and then the product is pelletized by a cutter, cooled in a water tank and dried in a boiling bin before being packaged to obtain the A component; 2) The linear low density polyethylene resin 1, the linear low density polyethylene resin 2, the catalyst, the antioxidant and the rheological master batch of the B component are uniformly mixed, added into a twin-screw extruder, extruded, pelletized and dried to obtain the B component. 3) mixing the A component obtained in step 1) and the B component obtained in step 2), and performing single-screw extrusion molding, water boiling or steam crosslinking to obtain the full black type silane crosslinked aerial insulating material.

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