A high CTI insulation material and cable

Abstract

This application discloses a high CTI insulation material and a cable. The high CTI insulation material comprises the following raw materials in parts by weight: 30-40 parts of polyethylene resin; 15-20 parts of polypropylene resin; and 5-7 parts of modifying additives. The modifying additives have a particle size of 4-5 μm and are a mixture of hydrated magnesium aluminate carbonate and the polymer product after hydrolysis of polysiloxane, wherein the polymer product after hydrolysis of polysiloxane coats the hydrated magnesium aluminate carbonate. The cable comprises a conductor and an insulation layer covering the conductor. The insulation layer is made of the high CTI insulation material of this application. The insulation material of this application has good tensile strength and excellent resistance to tracking. The cable of this application has good safety in harsh environments such as humidity and pollution.

Description

Technical Field

[0001] This application relates to the field of cables, and in particular to an insulation material and cable with a high CTI. Background Technology

[0002] With the increasingly widespread application of electrical equipment in daily life and industrial production, the safety of electrical equipment cannot be ignored, and the performance of insulation materials is crucial. Currently, there are many types of insulation materials on the market, but they often fall short in terms of resistance to tracking. Especially in harsh environments such as humidity and pollution, many insulation materials are prone to tracking, which can lead to short circuits, fires, and other accidents.

[0003] This is mainly because the tracking resistance index (CTI) and tracking resistance index (PTI) of these materials are not high enough to meet the requirements for use under special environmental conditions. Therefore, developing an insulating material that can ensure its mechanical properties, dielectric properties and other indicators meet the requirements and has good resistance to tracking has broad market prospects and application potential. Summary of the Invention

[0004] To ensure cable safety in harsh environments such as dampness and pollution, a high CTI insulation material and cable are provided.

[0005] The first inventive objective of this invention is achieved through the following technical solution:

[0006] A high CTI insulating material comprises the following raw materials in parts by weight:

[0007] 30-40 parts of polyethylene resin;

[0008] 15-20 parts of polypropylene resin;

[0009] 5-7 parts of modifying additives;

[0010] The modified additive has a particle size of 4-5 μm and is a mixture of hydrated magnesium aluminate carbonate and the polymer product after hydrolysis of polysiloxane, wherein the polymer product after hydrolysis of polysiloxane coats the hydrated magnesium aluminate carbonate.

[0011] By adopting the above technical solution, the modified additive is a mixture of magnesium carbonate hydrate and the polymer product after hydrolysis of polysiloxane. When magnesium carbonate hydrate is affected by the high temperature of electric arc, it will decompose and release gaseous water or gaseous water and carbon dioxide at the same time, depending on the temperature. This causes the insulating material to release gas from the surface of the insulating material when it comes into contact with the electric arc, blowing away the electric arc and thus reducing the scorching of the surface of the insulating material by the electric arc.

[0012] The polymerization products of polysiloxane after hydrolysis are coated on the surface of magnesium aluminate carbonate hydrate, which protects the relatively soft and low-strength magnesium aluminate carbonate hydrate and prevents it from cracking and peeling off under electric arc burning. This can improve the tracking resistance of magnesium aluminate carbonate hydrate.

[0013] Furthermore, by combining the high electron-hole content and high specific surface area of ​​the polymer products after the hydrolysis of polysiloxane with organic matter, the hydrated magnesium aluminate carbonate can be more evenly distributed in the insulating material, resulting in more stable resistance to tracking and reducing the negative effect of high addition of hydrated magnesium aluminate carbonate on the tensile strength of the insulating material. Ultimately, the tensile strength of the insulating material is also improved, thus obtaining an insulating material with excellent tensile strength and high CTI.

[0014] Optionally, the modified additive is prepared as follows:

[0015] The powder of hydrated magnesium aluminate carbonate was added to the modification solution and stirred to react. After the reaction was completed, the mixture was filtered, washed and dried to obtain the modification additive.

[0016] The modified liquid is a mixture of methyl silicate, methanol, ammonia, and water, with a pH of 9.5 to 9.7.

[0017] By adopting the above technical solution, the polymer product of polysiloxane after hydrolysis in the obtained modified additive has a large number of micropores inside, which can further improve the CTI of the insulating material.

[0018] Optionally, the mass ratio of silicate ester, lower alcohol, and water in the modified solution is 100:30:80.

[0019] With the above technical solution, the more micropores the polymer product after hydrolysis of polysiloxane has, the lower its strength will be. When prepared with the above ratio, the porosity and strength of the polymer product after hydrolysis of polysiloxane reach a better balance, and the tensile strength and tracking resistance of the insulating material are better.

[0020] Optionally, the mass ratio of the hydrated magnesium aluminate carbonate to the silicate ester is 100:35.

[0021] By adopting the above technical solution, the thicker the coating of the polysiloxane hydrolysis polymerization product on hydrated magnesium aluminate carbonate, the better the protection effect. However, if the coating amount is too large, it will inhibit the decomposition and gas release of hydrated magnesium aluminate carbonate. When prepared with the above ratio, the tensile strength and tracking resistance of the insulating material are both superior.

[0022] Optionally, the hydrated magnesium aluminate carbonate has a particle size of 0.8 μm.

[0023] By adopting the above technical solutions, the particle size of hydrated magnesium aluminate carbonate simultaneously affects the sensitivity and release amount of the gas released by the modified additive when exposed to an electric arc. If the particle size of hydrated magnesium aluminate carbonate is too small, the sensitivity is too high, but the release amount at the contact surface is small, resulting in poor resistance to tracking and easy erosion of the surrounding organic phase. If the particle size of hydrated magnesium aluminate carbonate is too large, the release amount is large, but the sensitivity is low, and erosion is likely to occur at lower voltages. When the particle size of hydrated magnesium aluminate carbonate is 0.8 μm, the resulting insulating material exhibits superior resistance to tracking.

[0024] Optionally, it also includes 3 to 4.2 parts of oil-extruded SBS.

[0025] By adopting the above technical solution, under conditions of low electric field strength in a humid medium, the formation of dendritic localized damage in a certain area of ​​the insulating material after a long period of electric field action is called water dendrite formation. If the medium contains impurities and moisture, colored dendritic localized damage will occur under the long-term action of a low electric field, which is called electrochemical dendrite formation. The added oil-filled SBS can inhibit water from wetting and penetrating into the insulating material, inhibit water dendrite formation and electrochemical dendrite formation, thereby improving the tracking resistance of the insulating material.

[0026] Optionally, 1.2 to 2 DOPOs may also be included.

[0027] By adopting the above technical solution, DOPO can suppress the free radical reaction activated by ionization, inhibit the damage of the insulating material in the arc contact area, and thus improve the tracking resistance of the insulating material.

[0028] The second objective of this invention is achieved through the following technical solution:

[0029] A cable includes a conductor and an insulation layer covering the conductor, the insulation layer being made of the aforementioned high CTI insulating material.

[0030] By adopting the above technical solution, the insulation layer of the cable of this application has good tensile strength and excellent resistance to tracking, and the cable has good safety in harsh environments such as humidity and pollution.

[0031] In summary, this application has at least the following beneficial effects:

[0032] 1. The modified additive is a mixture of magnesium carbonate hydrate and the polymer product after hydrolysis of polysiloxane. It has high bonding strength with organic matter, relatively uniform dispersion, is not easily broken, and releases gas during arc contact to reduce the scorching of the insulating material by the arc, thereby improving the resistance to tracking of the insulating material, so that the insulating material has good tensile strength and excellent resistance to tracking.

[0033] 2. This application also incorporates oil-extended SBS to inhibit water penetration into the insulating material, suppress water treeing and electrochemical treeing, thereby improving the tracking resistance of the insulating material. Attached Figure Description

[0034] Figure 1 This is a cross-sectional view of the cable in Example 12.

[0035] Figure Labels

[0036] 1. Sheath layer; 2. Reinforcing layer; 3. Inner lining layer; 4. Insulation layer; 5. Conductor. Detailed Implementation

[0037] raw material

[0038] The hydrated magnesium aluminate carbonate has a water content of 0.2–0.5 wt%, a dehydration initiation temperature of 350–360℃, and particle sizes of 0.2 μm, 0.8 μm, and 1.5 μm; its density is 2.1 g / cm³. 3 .

[0039] Fumed silica is a commercially available product with a particle size of 0.8 μm and a density of 2.2 g / cm³. 3 .

[0040] Methyl silicate and methanol are both commercially available products with a purity of 99 wt%.

[0041] The ammonia solution is commercially available concentrated ammonia solution with a concentration of 25 wt%.

[0042] SBS is Baling Petrochemical YH-815.

[0043] The white oil is No. 10 industrial white oil, with a kinematic viscosity of 48 cSt at 40℃, a specific gravity of 0.87, a pour point of -20℃, a flash point of 200℃, and a viscosity grade of 2.

[0044] The polyethylene resin is Dushanzi Petrochemical HDPE DMDA-8008H.

[0045] The polypropylene resin is Formosa Plastics K8009 PP.

[0046] DOPO is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, CAS No. 35948-25-5, and is a commercially available 99.5 wt% product.

[0047] Preparation Example 1

[0048] A modifying agent is formed by mixing magnesium carbonate hydrated aluminate with the polymer product after hydrolysis of polysiloxane, wherein the polymer product after hydrolysis of polysiloxane coats magnesium carbonate hydrated aluminate.

[0049] The particle size of hydrated magnesium aluminate carbonate is 0.8 μm.

[0050] The polymerization product of polysiloxane hydrolysis is formed by the polymerization of methyl silicate, methanol, and water under ammonia catalysis.

[0051] The specific preparation method is as follows:

[0052] S1: Mix methyl silicate and methanol to obtain a first preparation solution, then add water and ammonia to the first preparation solution to obtain a modified solution. The mass ratio of methyl silicate, methanol and water (including water in ammonia) in the modified solution is 100:30:80. The pH of the modified solution is adjusted to 9.6 by adjusting the ratio of ammonia and water added.

[0053] S2: After the modified liquid is prepared, 73.5 kg of the modified liquid is mixed with 100 kg of hydrated magnesium aluminate carbonate, heated to 50°C and stirred for 4 hours. The bottom solid material is observed to be sticky and agglomerated. The reaction is continued for 3 hours and then filtered to obtain the bottom material.

[0054] S3: Mix the bottom material with 500kg of water and 1kg of sodium lauryl sulfate and stir. Then add dilute hydrochloric acid to adjust the pH of the aqueous phase to 7.0. Continue stirring for 3 hours to neutralize the residual alkaline substances on the bottom material. After neutralization, filter to obtain the neutralized precipitate.

[0055] S4: Wash the neutralized precipitate with water until the chloride ion content in the washing liquid is less than 0.02wt%. After drying, sieve the particle size and use particles with a particle size of 4.5±0.5μm as the modifying agent.

[0056] Preparation Example 2

[0057] A modified additive, which differs from Preparation Example 1 in that the particle size of magnesium carbonate hydrated aluminate is 0.2 μm.

[0058] Preparation Example 3

[0059] A modified additive, which differs from Preparation Example 1 in that the particle size of magnesium carbonate hydrated aluminate is 1.5 μm.

[0060] Preparation Example 4

[0061] A modifying agent, which differs from Preparation Example 1 in that the reaction raw materials for the bottom material in S2 are 42 kg of modifying liquid and 100 kg of hydrated magnesium aluminate carbonate.

[0062] Preparation Example 5

[0063] A modifying agent, which differs from Preparation Example 1 in that the reaction raw materials for the bottom material in S2 are 105 kg of modifying liquid and 100 kg of hydrated magnesium aluminate carbonate.

[0064] Preparation Example 6

[0065] A modifying agent, which differs from Preparation Example 1 in that: in S1, the mass ratio of methyl silicate, methanol, and water in the modifying liquid is 100:15:40; in S2, the reaction raw materials for the bottom material are 54.25 kg of the modifying liquid and 100 kg of hydrated magnesium aluminate carbonate, that is, the mass ratio of hydrated magnesium aluminate carbonate to silicate ester is maintained at 100:35.

[0066] Preparation Example 7

[0067] A modifying agent, which differs from Preparation Example 1 in that the mass ratio of methyl silicate, methanol and water in the modifying liquid in S1 is 100:45:120; and the reaction raw materials of the bottom material in S2 are 92.75 kg of modifying liquid and 100 kg of hydrated magnesium aluminate carbonate, that is, the mass ratio of hydrated magnesium aluminate carbonate to silicate ester is maintained at 100:35.

[0068] Preparation Example 8

[0069] An oil-extruded SBS, the raw materials of which are SBS and white oil.

[0070] SBS is Baling Petrochemical YH-815; the white oil is No. 10 industrial white oil, with a kinematic viscosity of 48 cSt at 40℃, a specific gravity of 0.87, a pour point of -20℃, a flash point of 200℃, and a viscosity grade of 2.

[0071] The preparation process involves adding 100 kg of SBS particles into a mixer and stirring while adding 12.5 kg of white oil. After the addition is complete, stirring continues until the surface of the SBS particles is no longer sticky, thus obtaining oil-filled SBS.

[0072] Preparation Example 9

[0073] A modified additive differs from Preparation Example 1 in that it uses an equal volume of fumed silica with a particle size of 0.8 μm to replace hydrated magnesium aluminate carbonate, that is, 104.76 kg of fumed silica with a particle size of 0.8 μm is used to replace 100 kg of hydrated magnesium aluminate carbonate with a particle size of 0.8 μm.

[0074] Example 1

[0075] A high CTI insulating material, the raw materials of which are polyethylene resin, polypropylene resin, modifying additives, oil-extended SBS, and DOPO.

[0076] The modified additive was prepared in Preparation Example 1.

[0077] Oil-extended SBS was prepared in Preparation Example 8.

[0078] The specific preparation method is as follows:

[0079] 370 kg of polyethylene resin, 180 kg of polypropylene resin, 66 kg of modifying additives, 40 kg of oil-extended SBS, and 18 kg of DOPO were mixed evenly to obtain a mixed raw material.

[0080] The mixed raw materials are fed into a screw extruder for melt extrusion to obtain the insulating material.

[0081] When preparing the insulation layer of wires and cables, the raw materials are mixed using a continuous extrusion process, and the insulating material is directly coated onto the conductive core material to form the insulation layer.

[0082] When preparing test samples in sheet, plate, or strip form, the mixed raw materials are melted and extruded into the corresponding sample mold to obtain the sample.

[0083] Example 2

[0084] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 2.

[0085] Example 3

[0086] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 3.

[0087] Example 4

[0088] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 4.

[0089] Example 5

[0090] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 5.

[0091] Example 6

[0092] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 6.

[0093] Example 7

[0094] An insulating material with high CTI, which differs from Example 1 in that the modifying agent is prepared in Preparation Example 7.

[0095] Example 8

[0096] An insulating material with high CTI differs from Example 1 in that it uses an equal mass of SBS instead of oil-filled SBS.

[0097] Example 9

[0098] An insulating material with high CTI, which differs from Example 1 in that the amount of DOPO is 0.

[0099] Example 10

[0100] A high CTI insulating material differs from Example 1 in the amount of raw materials used, specifically: 300 kg polyethylene resin, 150 kg polypropylene resin, 50 kg modified additives, 30 kg oil-extended SBS, and 12 kg DOPO.

[0101] Example 11

[0102] A high CTI insulating material differs from Example 1 in the amount of raw materials used, specifically: 400 kg polyethylene resin, 200 kg polypropylene resin, 70 kg modifying additives, 42 kg oil-extended SBS, and 20 kg DOPO.

[0103] Comparative Example 1

[0104] An insulating material, the difference of Example 1, is that the modifying agent is replaced with magnesium carbonate aluminate hydrate of equal mass and particle size of 4.5±0.5μm.

[0105] Comparative Example 2

[0106] An insulating material, the difference from Example 1 is that the modifying agent is prepared in Preparation Example 9.

[0107] The insulating materials of Examples 1-11 and Comparative Examples 1-2 were subjected to tensile strength testing and CTI testing.

[0108] Tensile strength test: The tensile strength is tested according to GB / T 1040.3-2006.

[0109] CTI detection: According to GB4207-2022, select solution C and detect the maximum voltage CTI value of 50 drops.

[0110] The test results are shown in Table 1 below.

[0111] Table 1. Test results of insulating materials in Examples 1-11 and Comparative Examples 1-2

[0112]

[0113]

[0114] According to Table 1, the CTI of Example 1 is significantly better than that of Comparative Example 1 and Comparative Example 2, and the tensile strength of Example 1 is significantly better than that of Comparative Example 2.

[0115] Comparative Example 1 used magnesium carbonate hydrated aluminate as a single modifying agent; Comparative Example 2 used fumed silica as a single modifying agent.

[0116] The modified additive used in Example 1 was prepared in Preparation Example 1. It is a mixture of hydrated magnesium aluminate carbonate and the polymerized product after hydrolysis of polysiloxane. The hydrated magnesium aluminate carbonate decomposes when exposed to the high temperature of an electric arc, releasing gaseous water or both gaseous water and carbon dioxide depending on the temperature. This causes the insulating material to release gas from its surface when in contact with the arc, blowing away the arc and reducing the scorching effect of the arc on the insulating material surface. The polymerized product after hydrolysis of polysiloxane coats the surface of the hydrated magnesium aluminate carbonate, protecting the relatively soft and low-strength hydrated magnesium aluminate carbonate from... Magnesium aluminate carbonate hydrate bursts and peels off under electric arc burning, thereby improving its resistance to tracking. In addition, the high electron-hole content and high specific surface area of ​​the polymer products after polysiloxane hydrolysis, combined with organic matter, make magnesium aluminate carbonate hydrate more uniformly distributed in the insulating material, resulting in more stable tracking resistance. It also reduces the negative effect of high magnesium aluminate carbonate hydrate addition on the tensile strength of the insulating material, and the tensile strength of the insulating material is improved. Ultimately, the insulating material has good tensile strength and excellent tracking resistance.

[0117] Comparing Examples 1 and 2-3, the main difference lies in the particle size of the hydrated magnesium aluminate carbonate in the modifying agent. The particle size of hydrated magnesium aluminate carbonate affects both the sensitivity and release amount of the gas released when the modifying agent is exposed to an electric arc. If the particle size is too small, the sensitivity is too high, but the release amount at the contact surface is low, resulting in poor resistance to tracking and easy erosion of the surrounding organic phase. If the particle size is too large, the release amount is high, but the sensitivity is low, and erosion easily occurs even at lower voltages. In the test results, the CTI of Example 1 was higher than that of Examples 2-3. Therefore, when the particle size of hydrated magnesium aluminate carbonate in this application is 0.8 μm, the resulting insulating material exhibits superior resistance to tracking.

[0118] Comparing Examples 1 and 4-5, the differences lie in the amount of modifying liquid and magnesium aluminate carbonate hydrate used in the modifying agent, specifically the mass ratio of methyl silicate to magnesium aluminate carbonate hydrate. The proportions of magnesium aluminate carbonate hydrate and the post-hydrolysis polymerization products of polysiloxane in the modifying agent also differ, resulting in variations in coating thickness and coating condition. A thicker coating of magnesium aluminate carbonate hydrate with the post-hydrolysis polymerization products of polysiloxane provides better protection. However, excessive coating can inhibit the decomposition and gas release of magnesium aluminate carbonate hydrate and make the post-hydrolysis polymerization products of polysiloxane more dense, reducing the specific surface area and decreasing the bonding strength with organic matter. Based on the test results, the CTI of Example 1 is significantly better than that of Examples 4-5, and the tensile strength of Example 1 is greater than that of Examples 4-5. Therefore, in this application, the mass ratio of magnesium aluminate carbonate hydrate to silicate ester is 100:35, resulting in insulation materials with superior tensile strength and resistance to tracking.

[0119] Comparing Examples 1 and 6-7, it can be seen that the mass ratio of methyl silicate to magnesium carbonate hydrate aluminate in the three modifying agents is different, but the ratio of methyl silicate, methanol, and water in the modifying solution is different. That is, the concentration of methyl silicate and the hydrolysis and alcoholysis environment are different, which leads to different rates of methyl silicate hydrolysis and polymerization of hydrolysis products in the three modifying solutions. The porosity and distribution of the polysiloxane polymer products formed in the modifying agent after hydrolysis are different.

[0120] The more micropores in the polymer product after polysiloxane hydrolysis, the stronger the bond between the modifier and the organic phase. However, an increase in micropores leads to a decrease in the strength of the polymer product itself. The improvement in the tensile strength of insulating materials by the modifier is determined by the bond strength between the polymer product and the organic phase, as well as the strength of the polymer product itself. Furthermore, the micropores in the polymer product facilitate the decomposition and gas release of hydrated magnesium aluminate carbonate under the influence of an electric arc, but an increase in micropores also weakens the protective effect of the polymer product on hydrated magnesium aluminate carbonate. Therefore, the porosity of the polymer product after polysiloxane hydrolysis should not be too large or too small.

[0121] Based on the test results, the tensile strength of Example 1 is greater than that of Examples 6-7, and the CTI of Example 1 is greater than that of Examples 6-7. Therefore, the mass ratio of silicate ester, lower alcohol and water in the modified liquid in this application is 100:30:80, and the tensile strength and tracking resistance of the insulating material are better.

[0122] Comparing Examples 1 and 8, Example 1, which uses oil-filled SBS, has a significantly higher CTI than Example 8, which uses SBS. This is because, under conditions of low electric field strength in a humid medium, long-term action of the electric field causes dendritic localized damage in a certain area of ​​the insulating material, known as water dendrite formation. If the medium contains impurities and moisture, under long-term action of a low electric field, colored dendritic localized damage occurs, known as electrochemical dendrite formation. The oil-filled SBS in Example 1 can inhibit water penetration into the insulating material, inhibit water dendrite formation and electrochemical dendrite formation, thereby improving the tracking resistance of the insulating material.

[0123] Comparing Example 1 and Example 9, Example 1, which contains DOPO, has a higher CTI than Example 9, which does not contain DOPO. This is because DOPO can suppress free radical reactions activated by ionization, inhibit damage to the insulating material in the arc contact area, and thus improve the tracking resistance of the insulating material.

[0124] In addition, there are other superior embodiments during the research and development process of this application, such as Embodiments 10 and 11. The tensile strength and CTI of Embodiments 10 and 11 are significantly better than those of Comparative Examples 1 and 2. Therefore, the mass ratio of raw materials used in this application is controlled at polyethylene resin: polypropylene resin: modified additive = (30-40):(15-20):(5-7), and the resulting insulating materials can all have good tensile strength and resistance to tracking.

[0125] Example 12

[0126] As attached Figure 1 As shown, a cable includes a conductor 5 and an insulation layer 4.

[0127] There are multiple conductors 5, and an insulating layer 4 covers the outside of each conductor 5.

[0128] The reinforcing layer 2 is enclosed within all conductors 5, and the inner liner 3 is formed by polyolefin wire filling between the insulating layers 4 and between the insulating layers 4 and the reinforcing layer 2.

[0129] The reinforcing layer 2 is also covered by a sheath layer 1.

[0130] The insulating layer 4 is obtained by coating the conductor 5 with an insulating material, and the insulating material is one of the examples 1 to 11.

[0131] The insulation layer of the cable in this application has good tensile strength and excellent resistance to tracking, and the cable has good safety in harsh environments such as humidity and pollution.

[0132] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection claimed in this application.

Claims

1. A high CTI insulating material, characterized in that, The raw materials include the following parts by weight: 30-40 parts of polyethylene resin; 15-20 parts of polypropylene resin; 5-7 parts of modifying additives; The modified additive is a mixture of hydrated magnesium aluminate carbonate and the polymer product after hydrolysis of polysiloxane, and the polymer product after hydrolysis of polysiloxane coats hydrated magnesium aluminate carbonate. The particle size of hydrated magnesium aluminate carbonate is 0.8 μm; The polymerization product of polysiloxane hydrolysis is formed by the polymerization of methyl silicate, methanol, and water under ammonia catalysis. The specific preparation method is as follows: S1: Methyl silicate and methanol are mixed to obtain a first preparation solution. Water and ammonia are then added to the first preparation solution to obtain a modified solution. The mass ratio of methyl silicate, methanol, water and ammonia in the modified solution is 100:30:

80. The pH of the modified solution is adjusted to 9.6 by adjusting the ratio of ammonia and water. S2: After the modified liquid is prepared, 73.5 kg of the modified liquid is mixed with 100 kg of hydrated magnesium aluminate carbonate, heated to 50°C and stirred for 4 hours. The bottom solid material is observed to be sticky and agglomerated. The reaction is continued for 3 hours and then filtered to obtain the bottom material. S3: Mix the bottom material with 500kg of water and 1kg of sodium lauryl sulfate and stir. Then add dilute hydrochloric acid to adjust the pH of the aqueous phase to 7.

0. Continue stirring for 3 hours to neutralize the residual alkaline substances on the bottom material. After neutralization, filter to obtain the neutralized precipitate. S4: Wash the neutralized precipitate with water until the chloride ion content in the washing liquid is less than 0.02wt%. After drying, sieve the particle size and use particles with a particle size of 4.5±0.5μm as the modifying agent.

2. The high CTI insulating material according to claim 1, characterized in that, It also includes 3 to 4.2 parts of oil-extruded SBS.

3. The high CTI insulating material according to claim 1, characterized in that, It also includes 1.2 to 2 DOPO.

4. A cable comprising a conductor (5) and an insulating layer (4) covering the conductor, characterized in that, The insulating layer (4) is made of the high CTI insulating material as described in any one of claims 1 to 3.

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