Lightweight insulated cable for automobiles and process for the production thereof

Abstract

The application relates to the field of cables, in particular to a light-weight insulated cable for automobiles and a preparation process thereof. The light-weight insulated cable for automobiles comprises a sheath layer, an insulation layer and a conductor, the insulation layer is wrapped outside the conductor, a plurality of conductors wrapped with the insulation layer are twisted to form a multi-core group, and the sheath layer is wrapped outside the multi-core group; the preparation process comprises the following steps: twisting a plurality of copper wires to obtain the conductor; preparing insulation material, and then wrapping the insulation material outside the conductor to form the insulation layer; twisting the plurality of conductors wrapped with the insulation layer in the same direction to form the multi-core group; and wrapping the sheath layer outside the multi-core group to obtain the cable. The application has the advantage of further improving the insulation effect of the cable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cables, more particularly, it relates to a light-weight insulated cable for automobiles and a preparation process thereof. BACKGROUND

[0002] In the electrical system of an automobile, many wire and cable products are used. These wires and cables are mainly used to connect electrical equipment of various parts of the vehicle, so that the various parts of the automobile can transmit electrical signals and transmit electrical energy, thereby realizing various functions of the vehicle.

[0003] In the prior art, the in-vehicle high-voltage power cable of a new energy automobile (including a pure electric vehicle and a hybrid electric vehicle) usually adopts an insulation cable with a rated temperature of 125℃ or 150℃. However, when the new energy automobile is running under load, operations such as starting, braking, accelerating and decelerating will cause sharp changes in voltage, current and frequency, which may cause the temperature in the vehicle to rise sharply, thereby affecting the insulation effect of the cable, and even the cable may not be able to operate normally. Therefore, there is room for improvement. SUMMARY

[0004] In order to further improve the insulation effect of the cable, the present application provides a light-weight insulated cable for automobiles and a preparation process thereof.

[0005] In a first aspect, the present application provides a light-weight insulated cable for automobiles, which adopts the following technical solution:

[0006] A light-weight insulated cable for automobiles, comprising a sheath layer, an insulation layer and a conductor, the insulation layer is wrapped outside the conductor, a plurality of conductors wrapped with the insulation layer are twisted to form a multi-core group, and the sheath layer is wrapped outside the multi-core group.

[0007] The insulation layer is prepared from an insulation material, and according to the mass fraction, the insulation material comprises the following raw materials: 75-90 parts of low-density polyethylene, 5-10 parts of ethylene-vinyl acetate copolymer, 0.1-2 parts of antioxidant, 2-8 parts of crosslinking agent, 5-15 parts of sugarcane fiber, 1-5 parts of nanometer diamond, and 0.5-3 parts of nanometer silicon carbide.

[0008] By adopting the above technical solution, low-density polyethylene is selected as the main matrix of the insulation material, and the light weight property of low-density polyethylene is fully utilized to prepare a light-weight cable.

[0009] Under the cooperation of the sugarcane fiber, nanodiamond and nanosilicon carbide, the nanodiamond and nanosilicon carbide are attached to the network structure of the sugarcane fiber, and have a strong interaction with the low-density polyethylene and ethylene-vinyl acetate copolymer system. When the electrons are transmitted in the insulation layer, a large number of collisions occur to reduce the speed, which can effectively reduce the mobility of the charge carriers in the insulation layer system, thereby improving the insulation effect. Moreover, the sugarcane fiber, nanodiamond and nanosilicon carbide not only act as fillers in the system, but also can effectively improve the connection strength between the raw materials, so that the insulation layer is more dense and stable, and can still maintain good insulation effect after long-time and high-temperature use.

[0010] The vehicle cable often operates in a high temperature environment. The high temperature can cause a series of reactions such as molecular main chain oxidation reaction and proton transfer reaction, resulting in the breakage of the molecular main chain and the destruction of the crosslinking point, and a large number of defects are formed in the insulation layer, which affects the insulation effect. Under the support of the special structure, the crosslinking point is equivalent to being strengthened, and the degree of damage of the molecular main chain in the high-temperature environment is reduced.

[0011] Preferably, the mass ratio of the sugarcane fiber, nanodiamond and nanosilicon carbide is (10-13) : (2.5-4.0) : (0.5-1.5).

[0012] By adopting the above technical solution, the mass ratio of the sugarcane fiber, nanodiamond and nanosilicon carbide is further limited, so that the nanodiamond and nanosilicon carbide can be quickly and firmly attached to the network structure of the sugarcane fiber to form a more stable special structure, thereby further improving the insulation effect.

[0013] Preferably, the particle size of the nanodiamond is 45-80 nm, and the particle size of the nanosilicon carbide is 60-100 nm.

[0014] If the particle size of the nanodiamond and nanosilicon carbide is too small, agglomeration is easy to occur, which cannot be well dispersed in the system, and is also easy to fall off from the network structure of the sugarcane fiber. If the particle size is too large, the cooperation degree with the matrix will be weakened, thereby affecting the insulation effect.

[0015] By adopting the above technical solution, the particle size of the nanodiamond and nanosilicon carbide is further limited. Under the cooperation of the specific particle size, the cooperation effect between the sugarcane fiber and the nanodiamond and nanosilicon carbide is more sufficient.

[0016] Preferably, the crosslinking agent is one or a mixture of multiple of dicumyl peroxide, benzoyl peroxide and trimethylolpropane trimethacrylate.

[0017] Preferably, the crosslinking agent is dicumyl peroxide.

[0018] By adopting the above technical scheme, the selected crosslinking agent can promote the low-density polyethylene and ethylene-vinyl acetate copolymer system to have better and more stable crosslinking effect, and is beneficial to guarantee the insulation layer to have good insulation.

[0019] In a second aspect, the application provides a preparation process of a light-weight insulation cable for automobiles, which adopts the following technical scheme:

[0020] A preparation process of a light-weight insulation cable for automobiles, comprising the following steps:

[0021] Twist a plurality of copper wires to obtain a conductor;

[0022] Prepare an insulation material, and then coat the insulation material outside the conductor to form an insulation layer;

[0023] Twist a plurality of conductors coated with the insulation layer in the same direction to form a multi-core group;

[0024] Coat a sheath layer outside the multi-core group to obtain a cable;

[0025] The preparation method of the insulation material comprises the following steps:

[0026] Mix the sugar cane fiber, nanometer diamond and nanometer silicon carbide with water and a surfactant, and stir and mix them uniformly at 250-350 DEG C and 1000-1200 r / min, and then stand still; after solid-liquid separation, a pre-preparation material is obtained;

[0027] Mix the low-density polyethylene and ethylene-vinyl acetate copolymer uniformly, and then add the pre-preparation material, antioxidant and crosslinking agent and mix them uniformly, and then perform mixing, extrusion, cooling, granulation and drying to obtain the insulation material.

[0028] By adopting the above technical scheme, the sugar cane fiber, nanometer diamond and nanometer silicon carbide are treated in advance, so that the nanometer diamond and nanometer silicon carbide are loaded in the holes of the sugar cane fiber. Specifically, under the specific temperature and high-speed stirring, the water in the sugar cane fiber is removed to generate space, and the nanometer diamond and nanometer silicon carbide enter the above space of the sugar cane fiber and are not easy to fall off.

[0029] The subsequent sugar cane fiber serves as a carrier of the nanometer diamond and nanometer silicon carbide and is uniformly dispersed in the system of the low-density polyethylene and ethylene-vinyl acetate copolymer, which reduces the easy agglomeration and falling off of the nanometer diamond and nanometer silicon carbide in the matrix system, and makes the performance of the network structure more stable and sufficient.

[0030] When the automobile cable is in a high-temperature condition, the rich holes of the sugar cane fiber are beneficial to improve the heat dissipation effect of the insulation layer, thereby reducing the influence of high temperature on the performance of the cable.

[0031] Preferably, when preparing the preform, the sugar cane fibers are first soaked in an alkali solution with a concentration of 3-6%, and then the treated sugar cane fibers are taken out and mixed with nanodiamonds, nanosilicon carbide, water and a surfactant.

[0032] By using the above technical solution, the sugar cane fibers are first soaked in an alkali solution, so that the structure of the sugar cane fibers becomes rough, providing more attachment sites for nanodiamonds and nanosilicon carbide. Moreover, the soaking method of the alkali solution is also beneficial to improving the interfacial properties between the sugar cane fibers and low-density polyethylene and ethylene-vinyl acetate copolymer in the subsequent process, and has better mixing effect.

[0033] Preferably, the surfactant is one or a mixture of both of sodium sulfosuccinic acid ditridecyl ester and sodium sulfosuccinic acid diisooctyl ester.

[0034] Preferably, the mass of the surfactant is 10-20% of the total mass of the sugar cane fibers, nanodiamonds and nanosilicon carbide.

[0035] Preferably, the surfactant is sodium sulfosuccinic acid ditridecyl ester and sodium sulfosuccinic acid diisooctyl ester, and the mass ratio of sodium sulfosuccinic acid ditridecyl ester to sodium sulfosuccinic acid diisooctyl ester is 1:(0.9-1.2), based on the mass of sodium sulfosuccinic acid ditridecyl ester.

[0036] By using the above technical solution, the use of a specific type and proportion of surfactant is beneficial to promoting the uniform dispersion of nanodiamonds and nanosilicon carbide in water and loading them in the pores of the sugar cane fibers, so as to facilitate their subsequent role in the matrix system, and further improve the insulation effect of the insulation layer.

[0037] In summary, the present application has the following beneficial effects:

[0038] 1. Under the cooperation of sugar cane fibers, nanodiamonds and nanosilicon carbide, the nanodiamonds and nanosilicon carbide are attached to the network structure of the sugar cane fibers, and have strong interaction with the low-density polyethylene and ethylene-vinyl acetate copolymer system, which can effectively reduce the mobility of charge carriers in the insulation layer system, thereby improving the insulation effect.

[0039] 2. The sugar cane fibers, nanodiamonds and nanosilicon carbide act as fillers in the system, and the special network structure generated can effectively improve the connection strength between the raw materials, making the insulation layer more dense and stable, and still maintaining good insulation effect after long-term use.

[0040] 3. The sugarcane fibers, nanodiamonds, and nanosilicon carbide are pretreated to promote the loading of the nanodiamonds and nanosilicon carbide into the pores of the sugarcane fibers, and the sugarcane fibers are used as carriers of the nanodiamonds and nanosilicon carbide to uniformly disperse in the system of low-density polyethylene and ethylene-vinyl acetate copolymer. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a cross-sectional view of a light-weight insulation cable for automobiles according to Embodiment 1 of the present application.

[0042] Reference signs: 1, sheath layer; 2, insulation layer; 3, conductor. DETAILED DESCRIPTION

[0043] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0044] The raw materials used in the following examples and comparative examples are all commercially available products.

[0045] Example

[0046] Example 1

[0047] Reference Figure 1 A light-weight insulation cable for automobiles includes a sheath layer 1, an insulation layer 2, and a conductor 3. In this embodiment, the number of conductors 3 is 6, and the insulation layer 2 is wrapped around each individual conductor 3. The six conductors 3 wrapped with the insulation layer 2 are twisted in the same direction to form a multi-core group, and the sheath layer 1 is wrapped around the multi-core group.

[0048] The present application also discloses a preparation process of a light-weight insulation cable for automobiles, which includes the following steps:

[0049] Step 01): A plurality of copper wires with a diameter of 4 mm and a cross-sectional area of 10 mm 2 are twisted to obtain the conductor 3.

[0050] Step 02): An insulation material is prepared, and then the insulation material is put into an extruder. The extrusion temperature is adjusted to 150°C, and the extrusion pressure is adjusted to 150 MPa. The insulation material changes from a solid state to a viscous flow state.

[0051] The insulation material is extruded uniformly and continuously by the extruder, and is wrapped around the conductor 3 to form the insulation layer 2.

[0052] The conductor 3 wrapped with the insulation layer 2 is placed in a high-temperature steam box and continuously mixed with water vapor at 100°C for 4 h.

[0053] Step 03): The six conductors 3 obtained in step 03) are twisted in the same direction to form a multi-core group.

[0054] Step 04): coating a sheath layer 1 outside the multi-core group to obtain a cable.

[0055] The insulating material in step 02) comprises the following raw materials: low-density polyethylene, ethylene-vinyl acetate copolymer, antioxidant, crosslinking agent, sugarcane fiber, nanodiamond, and nanosilicon carbide.

[0056] The specific amounts of various raw materials are shown in Table 1.

[0057] The low-density polyethylene was purchased from Shanghai Tuoliang Industry Co., Ltd., with a brand name of 6030F.

[0058] The ethylene-vinyl acetate copolymer was purchased from Dongguan Bohao Plastic Raw Material Co., Ltd., with a brand name of P1403.

[0059] The antioxidant was antioxidant 300, with a CAS number of 1709-70-2.

[0060] The crosslinking agent was dicumyl peroxide.

[0061] The sugarcane fiber was purchased from Wuhan Huaxiang Kejie Biological Technology Co., Ltd., with a product number of 111.

[0062] The nanodiamond had a particle size of 50 nm and was purchased from Zhongke Jin Yan (Beijing) Technology Co., Ltd., with a number of DK-DC-50.

[0063] The nanosilicon carbide had a particle size of 100 nm and was purchased from Xuzhou Jietian New Material Technology Co., Ltd.

[0064] The preparation method of the insulating material comprises the following steps:

[0065] Step 1): The sugarcane fiber was soaked in a 5% NaOH solution for 25 min. Then the soaked sugarcane fiber was taken out and dried in a 65°C oven for 3 h, and then air-dried to constant weight in a well-ventilated place.

[0066] The mass ratio of sugarcane fiber to NaOH solution was 1:5.

[0067] Step 2): The water and surfactant were mixed uniformly, and then the treated sugarcane fiber, nanodiamond, and nanosilicon carbide in step 1) were added and mixed together. The conditions were set at 300°C and 1200 r / min, and the mixture was stirred until it was uniformly mixed. After standing for 2 h, the solid-liquid separation was performed, and the obtained solid material was dried in a 40°C oven for 3 h, and then air-dried to completely volatilize the solvent, to obtain the preformed material.

[0068] The amount of water used was 40 kg.

[0069] The mass of the surfactant is 1.6 kg. The surfactant is specifically sodium sulfosuccinic acid ditridecyl ester, sodium sulfosuccinic acid diisooctyl ester, the use amount of sodium sulfosuccinic acid ditridecyl ester is 0.8 kg, and the use amount of sodium sulfosuccinic acid diisooctyl ester is 0.8 kg.

[0070] Step 3): Set the internal mixer to 110℃, 50r / min, after reaching the preset temperature, add low-density polyethylene, ethylene-vinyl acetate copolymer and mix uniformly until the torque is stable.

[0071] Then add the prepared material and antioxidant into the internal mixer and mix uniformly for 5 min.

[0072] Then add the crosslinking agent into the internal mixer and mix for 3 min.

[0073] Step 4): Put the material obtained in step 3) into a low-speed mixer, and after the material temperature cools to 40℃, discharge.

[0074] Step 5): Granulate the material in step 4) by using a double-screw granulator, cut and dry to obtain the insulating material.

[0075] Example 2

[0076] A light-weight insulating cable for automobiles, which is different from example 1 in that in step 02), the mass ratio of sugarcane fiber, nanodiamond and nanosilicon carbide of the insulating material is 10:4.0:1.5. That is, the use amount of sugarcane fiber is 10 kg, the use amount of nanodiamond is 4 kg, and the use amount of nanosilicon carbide is 1.5 kg.

[0077] The particle size of the nanodiamond is 45 nm, and the particle size of the nanosilicon carbide is 60 nm.

[0078] The use amount of each raw material is shown in Table 1.

[0079] The preparation method of the insulating material is different from example 1 in that:

[0080] In step 1), the concentration of NaOH solution is 3%.

[0081] In step 2), the conditions are set to 250℃, 1100r / min.

[0082] The use amount of water is 40 kg.

[0083] The mass of the surfactant is 3.1 kg. The surfactant is specifically sodium sulfosuccinic acid ditridecyl ester, sodium sulfosuccinic acid diisooctyl ester, the use amount of sodium sulfosuccinic acid ditridecyl ester is 1.6 kg, and the use amount of sodium sulfosuccinic acid diisooctyl ester is 1.5 kg.

[0084] Example 3

[0085] A light weight insulated cable for automobile differs from example 1 in that in step 02), the mass ratio of the sugarcane fiber, nanodiamond, and nanosilicon carbide of the insulating material is 13:2.5:0.5. That is, the usage amount of the sugarcane fiber is 13 kg, the usage amount of the nanodiamond is 2.5 kg, and the usage amount of the nanosilicon carbide is 0.5 kg.

[0086] The particle size of the nanodiamond is 80 nm, and the particle size of the nanosilicon carbide is 100 nm.

[0087] The usage amount of each raw material is shown in Table 1.

[0088] The preparation method of the insulating material differs from example 1 in that:

[0089] In step 1), the concentration of the NaOH solution is 6%.

[0090] In step 2), the conditions are set to 350℃ and 1000 r / min.

[0091] The usage amount of water is 40 kg.

[0092] The mass of the surfactant is 1.6 kg. The surfactant is sodium sulfosuccinic acid ditridecyl ester, sodium sulfosuccinic acid diisooctyl ester, the usage amount of the sodium sulfosuccinic acid ditridecyl ester is 0.7 kg, and the usage amount of the sodium sulfosuccinic acid diisooctyl ester is 0.9 kg.

[0093] Example 4

[0094] A light weight insulated cable for automobile differs from example 1 in that in step 02), the particle size of the nanodiamond of the insulating material is 15 nm, and the particle size of the nanosilicon carbide is 150 nm.

[0095] Example 5

[0096] A light weight insulated cable for automobile differs from example 1 in that in step 02), the crosslinking agent of the insulating material is trimethylolpropane trimethacrylate.

[0097] The specific usage amount of each raw material is shown in Table 1.

[0098] The mass of the surfactant is 0.65 kg. The usage amount of the sodium sulfosuccinic acid ditridecyl ester is 0.32 kg, and the usage amount of the sodium sulfosuccinic acid diisooctyl ester is 0.33 kg.

[0099] Example 6

[0100] A light-weight insulated cable for automobile, which differs from Example 1 in that in step 02), the specific amount of each raw material in the insulating material is different, and the specific details are shown in Table 1.

[0101] The mass of the surfactant is 2.3 kg. The use amount of sodium tridecyl sulfosuccinate is 1.15 kg, and the use amount of sodium diisooctyl sulfosuccinate is 1.15 kg.

[0102] Table 1

[0103] Class Example 1 Example 2 Example 3 Example 5 Example 6 Low density polyethylene (kg) 80 80 80 75 90 Ethylene-vinyl acetate copolymer (kg) 8 8 8 5 10 Antioxidant (kg) 1 1 1 0.1 2 Crosslinking agent (kg) 6 6 6 2 8 Sugarcane fiber (kg) 12 10 13 5 15 Nanodiamond (kg) 3 4 2.5 1 5 Nanosilicon carbide (kg) 1 1.5 0.5 0.5 3

[0104] Example 7

[0105] A light-weight insulated cable for automobile, which differs from Example 1 in that in step 02), step 1) in the preparation of the insulating material is omitted.

[0106] Example 8

[0107] A light-weight insulated cable for automobile, which differs from Example 1 in that in the preparation method of the insulating material in step 02), the use amount of sodium tridecyl sulfosuccinate is 1.2 kg, and the use amount of sodium diisooctyl sulfosuccinate is 0.4 kg.

[0108] Example 9

[0109] A light-weight insulated cable for automobile, which differs from Example 1 in that in the preparation method of the insulating material in step 02), the surfactant is sodium tridecyl sulfosuccinate, the use amount of sodium tridecyl sulfosuccinate is 1.6 kg, and the use amount of sodium diisooctyl sulfosuccinate is 0 kg.

[0110] Comparative Example

[0111] Comparative Example 1

[0112] A light-weight insulated cable for automobile, which differs from Example 1 in that in the preparation method of the insulating material in step 02), the use amount of sugarcane fiber in the raw material of the insulating material is 0 kg, and the use amount of straw fiber is 12 kg.

[0113] Comparative Example 2

[0114] A light-weight insulated cable for automobile, which differs from Example 1 in that in the preparation method of the insulating material in step 02), the use amount of nanometer diamond in the raw material of the insulating material is 0 kg, and the use amount of nanometer aluminum oxide is 3 kg.

[0115] Comparative Example 3

[0116] A light weight insulated cable for automobile, which is different from example 1 in that the nano silicon carbide in the raw material of the insulation material in step 02) is replaced by nano silicon dioxide, the use amount of nano silicon carbide is 0 kg, and the use amount of nano silicon dioxide is 1 kg.

[0117] Comparative example 4

[0118] A light weight insulated cable for automobile, which is different from example 1 in that the use amount of sugarcane fiber in the raw material of the insulation material in step 02) is 3 kg, the use amount of nano diamond is 6.5 kg, and the use amount of nano silicon carbide is 6.5 kg.

[0119] Comparative example 5

[0120] A light weight insulated cable for automobile, which is different from example 1 in that in the preparation method of the insulation material in step 02), the condition of step 2) is set to 50℃, 2000r / min.

[0121] Performance detection test

[0122] 1. Insulation performance detection: the insulation materials of examples 1-9 and comparative examples 1-5 are detected according to GB / T 1695-2005 "Determination method of vulcanized rubber power frequency breakdown voltage strength and voltage resistance", the sample is tubular, the thickness is 1mm, and the breakdown voltage is recorded.

[0123] 2. Heat aging detection: according to the standard of GB / T 2951.12-2008 "General test method for cable and optical cable insulation and sheath material Part 12: general test method-heat aging test method", the insulation materials of examples 1-9 and comparative examples 1-5 are placed in the condition of 180℃ for 30d. After taking out the sample, test 1 is carried out again.

[0124] The detection results of the above tests 1-2 are shown in table 2.

[0125] Table 2

[0126]

[0127]

[0128] The insulation material of Comparative Example 1-3 is prepared on the basis of Example 1, and any of the sugarcane fiber, nanodiamond, and nanosilicon carbide is replaced. According to the test data of Example 1 and Comparative Example 1-3 in Table 2, the breakdown voltage of the insulation material of Example 1 is higher than that of Comparative Example 1-3. After heat aging treatment, the insulation material of Example 1 can still maintain a relatively high breakdown voltage, and the effect is also better than that of Comparative Example 1-3 after heat aging treatment. It is shown that the insulation material of Example 1 has good insulation effect, and can maintain a good and stable insulation effect after heat aging. However, the insulation material prepared by destroying the specific combination of the present application in Comparative Example 1-3 cannot realize the special cooperation between the sugarcane fiber, nanodiamond, and nanosilicon carbide, and cannot exert good insulation effect.

[0129] The insulation material of Comparative Example 4 is prepared on the basis of Example 1, and the use amount and the matching ratio of the sugarcane fiber, nanodiamond, and nanosilicon carbide are changed. According to the test data of Comparative Example 4, the insulation effect and the insulation effect after heat aging of the insulation material of Comparative Example 4 are slightly better than those of Comparative Example 1-3, but still much worse than those of Example 1. It is shown that not only the specific cooperation of the sugarcane fiber, nanodiamond, and nanosilicon carbide is required, but also the specific use amount and ratio of the three are required to exert the specific cooperation effect.

[0130] The insulation material of Example 4 is prepared on the basis of Example 1, and the particle size of the nanodiamond and the nanosilicon carbide is changed. The breakdown voltage of the prepared insulation material is slightly lower than that of Example 1, and the degree of breakdown voltage decrease after heat aging is also more obvious than that of Example 1. It is shown that further limiting the particle size of the nanodiamond and the nanosilicon carbide can more fully exert the cooperation effect between the sugarcane fiber, the nanodiamond, and the nanosilicon carbide, thereby having good and stable insulation effect.

[0131] Comparative Example 5 is prepared on the basis of Example 1, and the specific preparation temperature and stirring conditions are destroyed during preparation of the insulation material. The insulation and heat aging resistance effect of the prepared insulation material is obviously not as good as that of Example 1. The inventors speculate that because the specific temperature and speed can more fully remove the water in the sugarcane fiber, the nanodiamond and the nanosilicon carbide can be smoothly loaded on the sugarcane fiber, and firmly loaded, thereby improving the effect that can be exerted in the matrix subsequently.

[0132] According to the test data of Example 1 and Example 7 in Table 2, the insulation effect of the insulation material prepared by omitting the alkali washing step (Example 7) decreases. It is shown that soaking the sugarcane fiber in the appropriate alkali solution is beneficial to creating more sites for loading of the nanodiamond and the nanosilicon carbide, thereby affecting the performance of the insulation material.

[0133] Examples 8 and 9 are based on Example 1, but the proportion or selection of the surfactant is changed when the insulating material is prepared. The insulating material prepared has different degrees of decline in insulation and heat aging resistance. It is shown that further selection of specific types and proportions of surfactants can promote the dispersion of nanodiamonds and nanosilicon carbide in water, thereby improving the insulation and heat aging resistance of the insulating material.

[0134] The specific embodiments are merely illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A lightweight insulated cable for automobiles, characterized in that: The invention comprises a sheath layer (1), an insulating layer (2) and a conductor (3), wherein the insulating layer (2) is coated on the outside of the conductor (3), a plurality of conductors (3) coated with the insulating layer (2) are twisted to form a multi-core group, and the sheath layer (1) is coated on the outside of the multi-core group; The insulating layer (2) is made of an insulating material, which comprises the following raw materials in parts by mass: 75-90 parts of low-density polyethylene, 5-10 parts of ethylene-vinyl acetate copolymer, 0.1-2 parts of antioxidant, 2-8 parts of cross-linking agent, 5-15 parts of sugarcane fiber, 1-5 parts of nano-diamond, and 0.5-3 parts of nano-silicon carbide; The preparation method of the insulating material comprises the following steps: Mixing sugarcane fiber, nanodiamond, nanosilicon carbide, water and surfactant, stirring and mixing at 250-350°C and 1000-1200 r / min until uniform, and then letting it stand; after solid-liquid separation, obtaining a prefabricated material; The low-density polyethylene and ethylene-vinyl acetate copolymer are mixed evenly, and then the prefabricated material, antioxidant and cross-linking agent are added and mixed evenly, and then the insulation material is obtained by mixing, extruding, cooling, pelletizing and drying. The mass ratio of the sugarcane fiber, nanodiamond and nanosilicon carbide is (10-13): (2.5-4.0): (0.5-1.5); The particle size of the nanodiamond is 45-80nm, and the particle size of the nanosilicon carbide is 60-100nm; When preparing the prefabricated material, the sugarcane fiber is first immersed in an alkaline solution with a concentration of 3-6%, and then the treated sugarcane fiber is taken out and mixed with nano-diamond, nano-silicon carbide, water and a surfactant.

2. The lightweight insulated cable for automobiles according to claim 1, characterized in that: The cross-linking agent is a mixture of one or more of dicumyl peroxide, benzoyl peroxide, and trimethylolpropane trimethacrylate.

3. The lightweight insulated cable for automobiles according to claim 2, characterized in that: The cross-linking agent is dicumyl peroxide.

4. A process for preparing a lightweight insulated cable for automobiles according to any one of claims 1 to 3, characterized in that: The following steps are involved: Twisting a plurality of copper wires to obtain a conductor (3); preparing an insulating material, and then coating the conductor (3) with the insulating material to form an insulating layer (2); A plurality of conductors (3) coated with an insulating layer (2) are twisted in the same direction to form a multi-core group; A sheath layer (1) is coated on the multi-core group to obtain a cable.

5. The process for preparing a lightweight insulated cable for automobiles according to claim 4, characterized in that: The surfactant is one of sodium ditridecyl sulfosuccinate and sodium diisooctyl sulfosuccinate, or a mixture of the two.

6. The process for preparing a lightweight insulated cable for automobiles according to claim 5, wherein: The surfactant is sodium ditridecyl sulfosuccinate and sodium diisooctyl sulfosuccinate, and the mass ratio of sodium ditridecyl sulfosuccinate and sodium diisooctyl sulfosuccinate is 1:(0.9-1.2), with the mass of sodium ditridecyl sulfosuccinate as the benchmark.

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