Semi-conductive shielding material composition and application thereof, semi-conductive shielding material and preparation method and application thereof

Abstract

The invention relates to the technical field of power cables, and discloses a semiconductive shielding material composition and application thereof, a semiconductive shielding material and a preparation method and application thereof. The composition comprises an ethylene acrylate polymer, conductive carbon black, a cross-linking agent, a eutectic solvent and polyacrylate, the use amount of the ethylene acrylate polymer is 45-85 parts by mass, the use amount of the conductive carbon black is 15-40 parts by mass, the use amount of the cross-linking agent is 0.5-2 parts by mass, the use amount of the eutectic solvent is 2-5 parts by mass, and the use amount of the polyacrylate is 2-5 parts by mass; the eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, and the hydrogen bond donor is oxidizing acid; the hydrogen bond acceptor is selected from quaternary ammonium salt and / or zwitterion. The composition comprises a specific type of eutectic solvent and polyacrylate, so that the semiconductive shielding material prepared from the composition has better electrical performance, mechanical performance and surface smoothness.

Description

Technical Field

[0001] The present invention relates to the technical field of power cables, and in particular to a semi-conductive shielding material composition and application thereof, a semi-conductive shielding material and a preparation method and application thereof. Background Art

[0002] The semi-conductive shielding layer in the high-voltage cable is located between the conductor and the insulating layer, and plays a role in the cable structure to uniform the electric field and reduce the gap between the metal core and the insulating layer. In power transmission cables, cables with a rated voltage of 1.8 / 3.0kV or above that use cross-linked polyethylene and polyethylene as insulating layers should have conductor shielding to uniform the electric field. The semi-conductive shielding material is composed of a polymer matrix and conductive carbon black. The main indicators of the semi-conductive shielding layer include surface smoothness, volume resistivity, temperature-resistance coefficient and mechanical properties. Since the semi-conductive shielding layer contains very small carbon black, it is easy to form protrusions on the surface of the semi-conductive shielding layer, especially at high temperatures, the carbon black in the semi-conductive shielding layer is easy to penetrate into the insulating layer, affecting the interface state of the semi-conductive shielding-insulating layer. In addition, the volume resistivity of semi-conductive composite materials gradually increases with increasing temperature in the temperature range of 20-90°C, that is, it exhibits a positive temperature resistivity (PTC) characteristic. The rated operating temperature of high-voltage AC and DC cables is 90°C or 70°C, which is in the PTC region of semi-conductive composite materials. Therefore, the regulation of the PTC coefficient of semi-conductive composite materials for high-voltage cables is one of the key research areas of semi-conductive shielding materials.

[0003] Among the production methods of conductive carbon black, the more mature ones include the tank method, furnace method and pyrolysis method. The conductive carbon black produced in this process contains a small amount of oxygen-containing functional groups on its surface, such as hydroxyl, carboxyl, quinone, etc. The presence of oxygen-containing functional groups provides active sites for the chemical modification of conductive carbon black. However, the surface of conductive carbon black contains less oxygen-containing functional groups, the interaction between the modifier and the surface of conductive carbon black is weak, and the ability to optimize the electrical properties and surface smoothness of the carbon black shielding material is poor. Silane coupling agent, as the most widely used conductive carbon black modifier, has strict temperature requirements. Recently, many researchers have explored the effect of ionic liquids on the dispersibility of carbon black, but the raw materials for the preparation of ionic liquids are expensive and toxic, difficult to post-process during synthesis and processing, and poor biocompatibility are difficult to avoid. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art that the surface of semi-conductive shielding materials is not smooth and the PTC coefficient is high, and to provide a semi-conductive shielding composition and application, a semi-conductive shielding material and its preparation method and application. The composition includes a specific type of low eutectic solvent and polyacrylate, so that the semi-conductive shielding material prepared from the composition has better electrical properties, mechanical properties and surface smoothness.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a semi-conductive shielding material composition, wherein the composition comprises: ethylene acrylate polymer, conductive carbon black, a crosslinking agent, a low eutectic solvent and polyacrylate; The amount of the ethylene acrylate polymer is 45-85 parts by mass, the amount of the conductive carbon black is 15-40 parts by mass, the amount of the cross-linking agent is 0.5-2 parts by mass, the amount of the low eutectic solvent is 2-5 parts by mass, and the amount of the polyacrylate is 2-5 parts by mass; The low eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond donor is an oxidizing acid; and the hydrogen bond acceptor is selected from quaternary ammonium salts and / or zwitterions.

[0006] A second aspect of the present invention provides a semiconductive shielding material, wherein the semiconductive shielding material is prepared from the above-mentioned semiconductive shielding material composition.

[0007] The third aspect of the present invention provides a method for preparing the above-mentioned semiconductive shielding material, wherein the method comprises: S1. Under stirring conditions, the hydrogen bond acceptor and the hydrogen bond donor are first mixed to obtain a deep eutectic solvent; S2, performing a second mixing, extrusion, and granulation on the ethylene acrylic polymer, conductive carbon black, a low eutectic solvent, polyacrylate, an optional antioxidant, and an optional lubricant to obtain a granular material; S3, mixing the granular material with a cross-linking agent for absorption to obtain the semi-conductive shielding material.

[0008] A fourth aspect of the present invention provides an application of the above-mentioned semiconductive shielding material composition or semiconductive shielding material in a high-voltage cable.

[0009] Through the above technical scheme, the semi-conductive shielding material composition and application, the semi-conductive shielding material and the preparation method and application thereof provided by the present invention achieve the following beneficial effects: The semi-conductive shielding material composition provided by the present invention includes conductive carbon black, a low eutectic solvent and polyacrylate, and the hydrogen bond donor in the low eutectic solvent is an oxidizing acid. On the one hand, the high polarity and ionic properties of DES are utilized to penetrate into the interior of the conductive carbon black agglomerates, weaken the van der Waals force between the particles, and promote the conductive carbon black to form an effective conductive network in the matrix resin through electrostatic repulsion. On the other hand, the conductive carbon black is modified by the oxidizing acid in the low eutectic solvent, and the oxidizing acid component in DES is utilized to slightly oxidize the surface of the carbon black to form more oxygen-containing functional groups (-COOH, -OH), so that the polar ester group (-COOR) of the polyacrylate is combined with the oxygen-containing functional groups (such as -OH, -COOH) on the surface of the conductive carbon black through hydrogen bonds or dipole-dipole interactions to form chemical anchor points; at the same time, the polyacrylate flexible chain segment has excellent compatibility with the ethylene-acrylate polymer in the semi-conductive shielding material composition, reduces interfacial tension, and reduces phase separation, so that the semi-conductive shielding material prepared from the composition has better electrical, mechanical and surface smoothness. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the infrared spectra of the raw material conductive carbon black 2 and the modified carbon black powder in the preparation example. DETAILED DESCRIPTION

[0011] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0012] The first aspect of the present invention provides a semiconductive shielding material composition, wherein the composition comprises: Ethylene acrylic polymer, conductive carbon black, crosslinking agent, deep eutectic solvent and polyacrylate; The amount of the ethylene acrylate polymer is 45-85 parts by mass, the amount of the conductive carbon black is 15-40 parts by mass, the amount of the cross-linking agent is 0.5-2 parts by mass, the amount of the low eutectic solvent is 2-5 parts by mass, and the amount of the polyacrylate is 2-5 parts by mass; The low eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond donor is an oxidizing acid; and the hydrogen bond acceptor is selected from quaternary ammonium salts and / or zwitterions.

[0013] In the present invention, the semi-conductive shielding material composition includes conductive carbon black, a low eutectic solvent and polyacrylate, and the hydrogen bond donor in the low eutectic solvent is an oxidizing acid. On the one hand, the high polarity and ionic properties of DES are utilized to penetrate into the interior of the conductive carbon black agglomerates, weaken the van der Waals force between the particles, and promote the conductive carbon black to form an effective conductive network in the matrix resin through electrostatic repulsion. On the other hand, the conductive carbon black is modified by the oxidizing acid in the low eutectic solvent, and the oxidizing acid component in DES is utilized to slightly oxidize the surface of the carbon black to form more oxygen-containing functional groups (-COOH, -OH), which can be combined with the polar ester group (-COOR) of the polyacrylate through hydrogen bonds or dipole-dipole interactions with the oxygen-containing functional groups on the surface of the carbon black (such as -OH, -COOH) to form chemical anchor points; at the same time, the polyacrylate flexible chain segment has excellent compatibility with the ethylene acrylate polymer in the semi-conductive shielding material composition, reduces interfacial tension, and reduces phase separation, so that the semi-conductive shielding material prepared from the composition has better electrical properties, mechanical properties and surface smoothness. In addition, by infiltrating the carbon black agglomerates with low eutectic solvents, the electrostatic repulsion is combined with the compatibility of polyacrylate with the matrix resin and the large steric hindrance effect, and the two work together to achieve an ultra-smooth surface and a low PTC coefficient for the shielding material.

[0014] Furthermore, in the present invention, when the amount of each component in the semiconductive shielding material composition is controlled to meet the above range, the components cooperate with each other to further reduce the PTC coefficient of the shielding material prepared from the composition, and at the same time, reduce the surface protrusions of the shielding material.

[0015] In a specific embodiment of the present invention, the amount of the ethylene acrylate polymer is 45-75 parts by mass, the amount of the conductive carbon black is 20-35 parts by mass, the amount of the cross-linking agent is 0.6-1.5 parts by mass, the amount of the low eutectic solvent is 3-5 parts by mass, and the amount of the polyacrylate is 2-4 parts by mass.

[0016] According to the present invention, the oxidizing acid is selected from at least one of C4-C8 alkyl carboxylic acids containing hydroxyl groups, nitric acid, hypochlorous acid, chloric acid, chlorous acid and perchloric acid.

[0017] In the present invention, the above-mentioned specific type of oxidizing acid is selected to form more oxygen-containing functional groups (-COOH, -OH) on the surface of the conductive carbon black, thereby ensuring sufficient oxygen-containing functional groups.

[0018] In a specific embodiment of the present invention, the oxidizing acid is selected from at least one of malic acid, citric acid, tartaric acid, nitric acid, hypochlorous acid, chloric acid, chlorous acid and perchloric acid.

[0019] In a more preferred embodiment of the present invention, the oxidizing acid is selected from at least one of malic acid, tartaric acid and citric acid. The use of the more preferred oxidizing acid can further improve the compatibility of the conductive carbon black with the matrix resin, thereby making the shielding material obtained have better electrical properties.

[0020] According to the present invention, the quaternary ammonium salt is selected from at least one of choline chloride, tetrabutylammonium bromide and methylbenzenedimmonium chloride.

[0021] According to the present invention, the zwitterion is selected from at least one of betaine, N-methylglucosamine and glycine.

[0022] In the present invention, the above-mentioned specific types of quaternary ammonium salts and / or zwitterions are selected as hydrogen bond acceptors, which can not only quickly form a low eutectic solvent with the above-mentioned oxidizing acid, but also have a strong interaction with the conductive carbon black, thereby improving the modification effect of the conductive carbon black. In addition, the above-mentioned specific types of quaternary ammonium salts and / or zwitterions are low in price, thereby reducing the cost of the shielding material.

[0023] In a specific embodiment of the present invention, the hydrogen bond acceptor is selected from choline chloride and / or betaine, preferably choline chloride.

[0024] According to the present invention, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-3.

[0025] In the present invention, when the molar ratio of the hydrogen bond donor and the hydrogen bond acceptor is controlled to meet the above range, the hydrogen bond donor and the hydrogen bond acceptor have an appropriate ratio, and a deep eutectic solvent can be formed quickly.

[0026] Furthermore, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-2.5.

[0027] According to the present invention, the weight average molecular weight of the polyacrylate is 3000-8000 g / mol, and the molecular weight distribution is 1.2-2.3.

[0028] In the present invention, selecting polyacrylate with narrow molecular weight distribution and weight average molecular weight within the above range can significantly improve its compatibility with the matrix resin, thereby improving the electrical properties, mechanical properties and surface smoothness of the shielding material prepared from the composition.

[0029] Furthermore, the weight average molecular weight of the polyacrylate is 4000-7000 g / mol, and the molecular weight distribution is 1.2-2.

[0030] According to the present invention, the content of ester groups in the polyacrylate is 5-10 mol%.

[0031] According to the present invention, the cohesive energy density of the polyacrylate is 300-380 MJ / m3 .

[0032] In the present invention, when the content of ester groups and / or the cohesive energy density in the polyacrylate is controlled to meet the above range, it can ensure that the polyacrylate and the oxygen-containing functional groups on the surface of the conductive carbon black fully interact with each other, improve the dispersibility of the conductive carbon black in the matrix resin ethylene acrylate polymer, and at the same time, improve the bonding force between the conductive carbon black and the polymer matrix.

[0033] In the present invention, the content of ester groups in polyacrylate is measured by titration method.

[0034] Furthermore, the content of ester groups in the polyacrylate is 6-9 mol%.

[0035] Furthermore, the cohesive energy density of the polyacrylate is 310-370 MJ / m 3 .

[0036] In the present invention, there is no particular limitation on the specific type of polyacrylate, and conventional polyacrylates in the art, such as polybutyl acrylate, polymethyl acrylate, polyethyl acrylate, etc., may be used.

[0037] In the present invention, there is no particular limitation on the type of ethylene acrylate polymer, which may be a conventional type of ethylene acrylate polymer in the art, such as at least one of ethylene-butyl acrylate and ethylene-ethyl acrylate.

[0038] In a specific embodiment of the present invention, the content of ethylene structure in the ethylene acrylate polymer is 75-95wt%.

[0039] In the present invention, when the content of ethylene structure in the ethylene acrylate polymer meets the above range, the content of polar groups in the ethylene acrylate polymer is moderate, thereby further improving the electrical properties of the shielding material prepared from the composition.

[0040] According to the present invention, the melt index of the ethylene acrylic acid ester polymer at 190° C. and 2.16 kg is 5-25 g / 10 min, preferably 7-20 g / 10 min.

[0041] According to the present invention, the elongation at break of the ethylene acrylate polymer is 500-900%, preferably 600-850%.

[0042] According to the present invention, the density of the ethylene acrylate polymer is 0.88-0.95 g / cm 3 , preferably 0.91-0.93 g / cm 3 .

[0043] In the present invention, by selecting an ethylene acrylate polymer having at least one of melt index, elongation at break and density satisfying the above range, the semiconductive shielding material prepared from the composition containing the ethylene acrylate polymer can have excellent electrical properties and surface smoothness.

[0044] According to the present invention, the average particle size of the conductive carbon black is 30-75 nm, and the BET specific surface area is 50-150 m 2 / g; oil absorption value 140-210cc / 100g.

[0045] In the present invention, when a conductive carbon black having an average particle size, a BET specific surface area and an oil absorption value that meets the above-mentioned range is used, the specific surface area of ​​the conductive carbon black is larger, the degree of voids between the carbon black aggregates is larger, and there are more carbon black particles per unit volume, so that the carbon black particles can easily form a conductive network in the matrix resin, thereby significantly improving the electrical properties of the shielding material prepared from the composition.

[0046] Furthermore, the average particle size of the conductive carbon black is 35-50 nm, and the BET specific surface area is 50-100 m 2 / g; oil absorption value 160-205cc / 100g.

[0047] In the present invention, there is no particular limitation on the specific type of the conductive carbon black, as long as the average particle size, BET specific surface area and oil absorption value of the conductive carbon black meet the requirements of the present invention.

[0048] According to the present invention, the crosslinking agent is a peroxide crosslinking agent.

[0049] In the present invention, there is no particular limitation on the specific type of the peroxide crosslinking agent, which may be a conventional peroxide crosslinking agent in the art, such as at least one of BIBP, DCP, and dipentadienyl vulcanizing agent.

[0050] In the present invention, in order to improve the extrusion performance of the shielding material, preferably, the composition further comprises a lubricant, wherein the amount of the lubricant is 0.2-2 parts by mass, preferably, the amount of the lubricant is 0.5-1.5 parts by mass.

[0051] In the present invention, there is no particular limitation on the specific type of the lubricant, and the lubricant may be a conventional lubricant in the art, such as at least one of zinc stearate, ethylene bis stearamide and pentaerythritol.

[0052] In the present invention, in order to improve the aging resistance of the semiconductive shielding material, preferably, the composition further comprises an antioxidant, wherein the amount of the antioxidant is 0.2-2 parts by mass, preferably, the amount of the antioxidant is 0.5-1.5 parts by mass.

[0053] In the present invention, there is no particular limitation on the specific type of antioxidant, which may be a conventional type of antioxidant in the art, such as at least one of the antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMQ), antioxidant 1010 and antioxidant 300.

[0054] In the present invention, the composition may also include other conventional additives in the art, such as dispersants, co-crosslinking agents, etc. The types and amounts of the above additives can be selected according to actual needs and added according to conventional amounts in the art.

[0055] A second aspect of the present invention provides a semiconductive shielding material, wherein the semiconductive shielding material is prepared from the above-mentioned semiconductive shielding material composition.

[0056] The third aspect of the present invention provides a method for preparing the above-mentioned semiconductive shielding material, wherein the method comprises: S1. Under stirring conditions, the hydrogen bond acceptor and the hydrogen bond donor are first mixed to obtain a deep eutectic solvent; S2, performing a second mixing, extrusion, and granulation on the ethylene acrylic polymer, the conductive carbon black, the low eutectic solvent, the polyacrylate, the optional antioxidant, and the optional lubricant to obtain a granular material; S3, mixing the granular material with a cross-linking agent for absorption to obtain the semi-conductive shielding material.

[0057] The raw materials for preparing the semiconductor shielding material in the third aspect of the present invention adopt the composition described in the first aspect of the present invention. The types of raw material compositions in the third aspect of the present invention are exactly the same as those described in the first aspect of the present invention. In order to avoid repetition, the present invention will not be described in detail in the third aspect, and those skilled in the art should not understand it as a limitation of the present invention.

[0058] In the present invention, the semi-conductive shielding material prepared by the above method can make the components in the composition cooperate with each other, and improve the compatibility of the conductive carbon black with the matrix resin, so that the shielding material prepared thereby has low resistivity, low PTC coefficient and ultra-smooth surface. Specifically, under stirring conditions, the hydrogen bond acceptor and the hydrogen bond donor are first mixed to prepare a low eutectic solvent, so that the formed low eutectic solvent contains rich hydrogen bonds, and the low eutectic solvent is secondly mixed with the conductive carbon black, etc., so that the conductive carbon black nanoparticles can be fully coated and the conductive carbon black is prevented from agglomerating in the matrix resin.

[0059] According to the present invention, in step S1, the stirring speed is 100-1000 r / min.

[0060] In the present invention, when the stirring speed is controlled to meet the above range, a deep eutectic solvent can be quickly formed under mild conditions.

[0061] Furthermore, the stirring speed is 300-800r / min.

[0062] In a preferred embodiment of the present invention, the first mixing is performed under heating conditions.

[0063] In the present invention, the first mixing is performed under heating conditions, which helps the hydrogen bond acceptor and the hydrogen bond donor to fully contact each other, so as to quickly form a deep eutectic solvent.

[0064] According to the present invention, in step S1, heating is performed so that the temperature of the first mixture is 50-100°C.

[0065] In the present invention, when the heating temperature is controlled to meet the above range, it is possible to ensure that the hydrogen bond donor and the hydrogen bond acceptor quickly form a low eutectic solvent while avoiding the decomposition of the hydrogen bond acceptor and the hydrogen bond donor due to excessively high temperature.

[0066] Furthermore, the first mixture is heated so that the temperature thereof is 60-90°C.

[0067] In the present invention, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-3, preferably 1:1-2.5.

[0068] According to the present invention, in step S2, the second mixing is performed in an internal mixer.

[0069] According to the present invention, the temperature of the second mixing is 130-180° C., and the time of the second mixing is 10-30 min.

[0070] In the present invention, when the temperature and time of the second mixing are controlled to meet the above range, the components of the composition can be fully mixed and evenly mixed, ensuring full contact between the low eutectic solvent, conductive carbon black, acrylic polymer and matrix resin ethylene acrylic polymer, forming a strong interaction force, improving the compatibility between the components, and further improving the electrical properties of the shielding material obtained thereby.

[0071] Furthermore, the temperature of the second mixing is 140-170° C., and the time of the second mixing is 12-25 min.

[0072] In the present invention, the extrusion and granulation in step S2 can be carried out in conventional equipment in the art, such as a twin-screw extruder or a reciprocating single-screw extruder.

[0073] According to the present invention, in step S3, the absorption conditions include: the absorption temperature is 50-80° C., and the absorption time is 2-6 hours.

[0074] In the present invention, the absorption is carried out under the above conditions, which can ensure that the crosslinking agent is completely absorbed, thereby improving the electrical properties, mechanical properties and surface smoothness of the shielding material obtained thereby.

[0075] Furthermore, the absorption conditions include: the absorption temperature is 60-75° C., and the absorption time is 2-4 hours.

[0076] A fourth aspect of the present invention provides a use of the above-mentioned semiconductive shielding material composition or the above-mentioned semiconductive shielding material in a high-voltage cable.

[0077] The present invention will be described in detail below through examples. In the following examples, the tensile strength and elongation at break of the semi-conductive shielding material are measured by a universal testing machine method, and the test standard is GB / T 1040.3-2022; The volume resistivity of the semi-conductive shielding material is measured by a rubber semi-conductive tester method, according to the test standard GB / T3048-2007, Part 3, Volume Resistivity Test of Semi-conductive Rubber and Plastic Materials; wherein, PTC coefficient = 90°C volume resistivity / 23°C volume resistivity.

[0078] The smoothness of the semi-conductive shielding material was measured using the OCS surface protrusion detection method. Specifically, the test was conducted under an optical scanning device with a high-resolution camera at a scanning speed of 0.03 m. 2 / min, the surface of the sample strip is scanned by a high-resolution camera, and the size and number of surface protrusions are characterized by testing a total surface area of ​​about 1m 2 For the samples, record the number of surface protrusions with heights greater than 50 μm and greater than 75 μm.

[0079] Conductive carbon black 1: a commercial product of Cabot Corporation with the brand name VXC500, with an average particle size of 35 nm, an oil absorption value of 148 cc / 100 g, and a BET value of 59 m 2 / g; Conductive carbon black 2: Commercially available product of Yiruishi Co., Ltd., brand 250G, with an average particle size of 45nm, an oil absorption value of 178cc / 100g, and a BET value of 61m 2 / g; Conductive carbon black 3: Denka's acetylene black, average particle size 40nm, oil absorption value 208cc / 100g, BET 72m 2 / g; Ethylene-butyl acrylate: a commercial product of Repsol with the brand name E1770; the melt index at 190°C and 2.16 kg is 7 g / 10 min, the elongation at break is 800%, and the density is 0.924 g / cm 3 , the ethylene structure content is 83wt%; Ethylene-ethyl acrylate: a commercial product of DuPont with the brand name Elvaloy AC2715; the melt index at 190°C and 2.16 kg is 7 g / 10 min, the elongation at break is 740%, and the density is 0.93 g / cm 3 , the ethylene structure content is 85wt%; Other raw materials used in the examples and comparative examples are all commercially available.

[0080] In the following examples and comparative examples, unless otherwise specified, one portion means 1 g.

[0081] Preparation Example The hydrogen bond acceptor (choline chloride) and the acidic oxidative hydrogen bond donor (malic acid) were added into a clean and dry single-mouth round-bottom flask at a molar ratio of 1:2; the round-bottom flask containing the mixture was placed in an 80°C water bath, and the mixture was mechanically stirred at a speed of 500r / min; after the mixture reacted to become a stable and uniform liquid, it was cooled at room temperature. The uniform liquid was the low eutectic solvent, and 235 parts of conductive carbon black, polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 350 MJ / m 3 ) 4 parts of the above-mentioned low eutectic solvent were mixed and dried in an internal mixer to obtain modified carbon black powder; wherein the second mixing temperature was 160°C and the time was 20 minutes. The modified carbon black powder was subjected to infrared testing, and the results were as follows: Figure 1 shown.

[0082] Depend on Figure 1 It can be seen that the carbon black in the prepared pellets is located at -3433cm -1 The peak area of ​​the characteristic peak of -OH / -COOH functional group at 3433 cm-1 is obviously increased, indicating that the deep eutectic solvent has a certain oxidizing effect on carbon black. In addition, the -OH peak increases from 3433 cm-1 to -1 Migrate to 3420cm -1 This indicates that there is a hydrogen bond interaction between the two. In addition, the -1 , for CH 2 The stretching vibration is located at 1733cm -1 It is the carbonyl peak in the ester group, indicating the successful introduction of polybutyl acrylate.

[0083] Example 1 S1. Add hydrogen bond acceptor (choline chloride) and acidic oxidative hydrogen bond donor (citric acid) in a molar ratio of 1:1 into a clean and dry single-necked round-bottom flask; place the round-bottom flask containing the mixture in an 80°C water bath, and mechanically stir the mixture at a speed of 500r / min; after the mixture reacts to become a stable and uniform liquid, cool it at room temperature. The uniform liquid is the low eutectic solvent A1.

[0084] S2, 140 parts of conductive carbon black, 47.5 parts of ethylene-butyl acrylate, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 5 parts of low eutectic solvent (choline chloride / citric acid), polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 360 MJ / m 3 ) 5 parts were added into an internal mixer for second mixing, extrusion granulation and drying to obtain granular material; wherein the temperature of the second mixing was 160°C and the time was 20 min.

[0085] S3. Add 1 part of cross-linking agent BIBP to the obtained granular material and mix evenly. After absorbing at 60° C. for 4 hours, a semi-conductive shielding material S1 is obtained.

[0086] Example 2 S1. Add hydrogen bond acceptor (choline chloride) and acidic oxidative hydrogen bond donor (malic acid) in a molar ratio of 1:2 into a clean and dry single-necked round-bottom flask; place the round-bottom flask containing the mixture in an 80°C water bath, and mechanically stir the mixture at a speed of 500r / min; after the mixture reacts to become a stable and uniform liquid, cool it at room temperature, and the uniform liquid is the low eutectic solvent A2.

[0087] S2, 55.5 parts of ethylene-butyl acrylate, 235 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 3 parts of low eutectic solvent (choline chloride / malic acid), polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 360 MJ / m 3 ) 4 parts were added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular materials; wherein, the temperature of the second mixing was 160°C and the time was 20 min.

[0088] S3. Add 1 part of cross-linking agent BIBP to the obtained granular material and mix evenly. After absorbing at 60° C. for 4 hours, a semi-conductive shielding material S2 is obtained.

[0089] Example 3 S1. Add hydrogen bond acceptor (choline chloride) and acidic oxidative hydrogen bond donor (malic acid) in a molar ratio of 1:3 into a clean and dry single-necked round-bottom flask; place the round-bottom flask containing the mixture in an 80°C water bath, and mechanically stir the mixture at a speed of 500r / min; after the mixture reacts to become a stable and uniform liquid, cool it at room temperature. The uniform liquid is the low eutectic solvent A3.

[0090] S2, 62.5 parts of ethylene-butyl acrylate, 330 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 2 parts of low eutectic solvent (choline chloride / malic acid), polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 360 MJ / m 3 ) 3 parts were added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular materials; wherein, the temperature of the second mixing was 160°C and the time was 20 min.

[0091] S3. Add 1 part of cross-linking agent BIBP to the obtained granular material and mix evenly. After absorbing at 60° C. for 4 hours, a semi-conductive shielding material S3 is obtained.

[0092] Example 4 S1. Add hydrogen bond acceptor (choline chloride) and acidic oxidative hydrogen bond donor (nitric acid) in a molar ratio of 1:2 into a clean and dry single-necked round-bottom flask; place the round-bottom flask containing the mixture in an 80°C water bath, and mechanically stir the mixture at a speed of 500r / min; after the mixture reacts to become a stable and uniform liquid, cool it at room temperature. The uniform liquid is the low eutectic solvent A4.

[0093] S2, 68.5 parts of ethylene-ethyl acrylate, 25 parts of conductive carbon black 2, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 2 parts of low eutectic solvent (choline chloride / nitric acid), polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 360 MJ / m 3 ) 2 parts are added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular materials; wherein, the temperature of the second mixing is 160°C and the time is 20 minutes.

[0094] S3. Add 1 part of cross-linking agent BIBP to the obtained granular material and mix evenly. After absorbing at 60° C. for 4 hours, a semi-conductive shielding material S4 is obtained.

[0095] Example 5 S1. Same as step S1 in Example 2.

[0096] S2, 55.5 parts of ethylene-butyl acrylate, 235 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 3 parts of low eutectic solvent (choline chloride / malic acid), polyethyl acrylate (weight average molecular weight 5000g / mol, ester content 8mol%, molecular weight distribution 1.2, cohesive energy density 350 MJ / m 3 ) 4 parts were added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular materials; wherein, the temperature of the second mixing was 160°C and the time was 20 min.

[0097] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material S5 is obtained.

[0098] Example 6 S1. Same as step S1 in Example 2.

[0099] S2 is similar to step S2 of Example 2, except that the weight average molecular weight of polybutyl acrylate is 5000 g / mol, the ester content is 3 mol%, the molecular weight distribution is 1.4, and the cohesive energy density is 320 MJ / m 3 .

[0100] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material S6 is obtained.

[0101] Example 7 S1. Same as step S1 in Example 2.

[0102] S2 is similar to step S2 of Example 2, except that the weight average molecular weight of polybutyl acrylate is 5000 g / mol, the ester content is 5 mol%, the molecular weight distribution is 1.5, and the cohesive energy density is 340 MJ / m 3 .

[0103] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material S7 is obtained.

[0104] Example 8 S1. Similar to step S1 of Example 2, except that the molar ratio of choline chloride to malic acid is 1:4 to prepare a low eutectic solvent.

[0105] S2. The same as step S2 of embodiment 2.

[0106] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material S8 is obtained.

[0107] Example 9 S1. Same as step S1 in Example 2.

[0108] S2 is similar to step S2 of Example 2, except that: ethylene-butyl acrylate is 75.5 parts, conductive carbon black 2 is 18 parts, low eutectic solvent (choline chloride / malic acid) is 2 parts, and polybutyl acrylate is 2 parts.

[0109] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material S9 is obtained.

[0110] Comparative Example 1 S1 is not performed; S2. Add 35 parts of conductive carbon black, 62.5 parts of ethylene-butyl acrylate, 1 part of antioxidant TMQ, and 0.5 parts of lubricant zinc stearate into an internal mixer for internal mixing, extrusion granulation, and drying to obtain granular material; wherein the mixing temperature is 160° C. and the mixing time is 20 min.

[0111] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material DS1 is obtained.

[0112] Comparative Example 2 S1. The same as step S1 in Example 2.

[0113] S2. Add 59.5 parts of ethylene-butyl acrylate, 35 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, and 3 parts of low eutectic solvent (choline chloride / malic acid) into an internal mixer for internal mixing, extrusion granulation, and drying to obtain granules; wherein the mixing temperature is 160° C. and the mixing time is 20 min.

[0114] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material DS2 is obtained.

[0115] Comparative Example 3 S1 is not performed; S2, 58.5 parts of ethylene-butyl acrylate, 35 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, polybutyl acrylate (weight average molecular weight 7000g / mol, ester content 8mol%, molecular weight distribution 1.3, cohesive energy density 360 MJ / m 3 ) 4 parts were added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular material; wherein, the mixing temperature was 160°C and the mixing time was 20 min.

[0116] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material DS3 is obtained.

[0117] Comparative Example 4 S1. Similar to step S1 of Example 2, except that an equimolar amount of oxalic acid is used instead of malic acid to obtain a deep eutectic solvent (choline chloride / oxalic acid).

[0118] S2. Similar to step S2 of Example 2, except that the low eutectic solvent (choline chloride / malic acid) in Example 2 is replaced by a low eutectic solvent (choline chloride / oxalic acid) of equal mass.

[0119] S3 is the same as step S3 of embodiment 2. A semi-conductive shielding material DS4 is obtained.

[0120] Comparative Example 5 S1. The same as step S1 in Example 2.

[0121] S2, 71.5 parts of ethylene-butyl acrylate, 10 parts of conductive carbon black 2, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 8 parts of low eutectic solvent (choline chloride / malic acid), polybutyl acrylate (weight average molecular weight of 7000 g / mol, ester content of 8 mol%, molecular weight distribution of 1.3, cohesive energy density of 360 MJ / m 3 ) 8 parts were added into an internal mixer for internal mixing, extrusion granulation and drying to obtain granular material; wherein, the temperature of the second mixing was 160°C and the time was 20 min.

[0122] S3 is the same as step S3 of Example 2. A semi-conductive shielding material DS5 is obtained.

[0123] Comparative Example 6 S1. The same as step S1 in Example 2.

[0124] S2, 45.5 parts of ethylene-butyl acrylate, 250 parts of conductive carbon black, 1 part of antioxidant TMQ, 0.5 parts of lubricant zinc stearate, 1 part of low eutectic solvent (choline chloride / oxalic acid), polybutyl acrylate (weight average molecular weight of 7000 g / mol, ester content of 8 mol%, molecular weight distribution of 1.3, cohesive energy density of 360 MJ / m 3 ) 1 part is added into an internal mixer for internal mixing, extrusion granulation, and drying to obtain granular material; wherein, the temperature of the second mixing is 160°C and the time is 20 minutes.

[0125] S3 is the same as step S3 of Example 1. A semi-conductive shielding material DS6 is obtained.

[0126] The semiconductive shielding materials prepared in the examples and comparative examples were pressed into sheets at 180° C. and 15 MPa to prepare samples to be tested. The properties of the samples to be tested were tested, and the results are shown in Table 1.

[0127] Table 1

[0128] It can be seen from the results in Table 1 that, compared with Comparative Examples 1-6, the semi-conductive shielding materials prepared using the compositions of Examples 1-9 of the present invention have excellent electrical properties, mechanical properties and surface smoothness.

[0129] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A semiconductive shielding material composition, characterized in that: The composition comprises: ethylene acrylate polymer, conductive carbon black, a crosslinking agent, a low eutectic solvent and polyacrylate; The amount of the ethylene acrylate polymer is 45-85 parts by mass, the amount of the conductive carbon black is 15-40 parts by mass, the amount of the cross-linking agent is 0.5-2 parts by mass, the amount of the low eutectic solvent is 2-5 parts by mass, and the amount of the polyacrylate is 2-5 parts by mass; The low eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond donor is an oxidizing acid; and the hydrogen bond acceptor is selected from quaternary ammonium salts and / or zwitterions.

2. The semiconductive shielding material composition according to claim 1, wherein: The oxidizing acid is selected from at least one of a C4-C8 alkyl carboxylic acid containing a hydroxyl group, nitric acid, hypochlorous acid, chloric acid, chlorous acid and perchloric acid; And / or, the quaternary ammonium salt is selected from at least one of choline chloride, tetrabutylammonium bromide and methylbenzenedimmonium chloride; and / or, the zwitterion is selected from at least one of betaine, N-methylglucosamine and glycine; And / or, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-3.

3. The semiconductive shielding material composition according to claim 1, wherein: The weight average molecular weight of the polyacrylate is 3000-8000 g / mol, and the molecular weight distribution is 1.2-2.3; and / or, the content of ester groups in the polyacrylate is 5-10 mol%; And / or, the cohesive energy density of the polyacrylate is 300-380 MJ / m 3 .

4. The semiconductive shielding material composition according to any one of claims 1 to 3, wherein: The ethylene acrylate polymer is selected from ethylene-butyl acrylate and / or ethylene-ethyl acrylate; and / or, the content of ethylene structure in the ethylene acrylate polymer is 75-95wt%; and / or, the ethylene acrylic acid ester polymer has a melt index of 5-25 g / 10 min at 190° C. and 2.16 kg; and / or, the elongation at break of the ethylene acrylate polymer is 500-900%; And / or, the density of the ethylene acrylate polymer is 0.88-0.95 g / cm -3 .

5. The semiconductive shielding material composition according to any one of claims 1 to 3, wherein: The conductive carbon black has an average particle size of 30-75 nm and a BET specific surface area of ​​50-150 m 2 / g; oil absorption value 140-210cc / 100g; And / or, the cross-linking agent is a peroxide cross-linking agent.

6. The semiconductive shielding material composition according to any one of claims 1 to 3, wherein: The composition further comprises a lubricant, wherein the amount of the lubricant is 0.2-2 parts by mass.

7. The semiconductive shielding material composition according to any one of claims 1 to 3, wherein: The composition further comprises an antioxidant, wherein the amount of the antioxidant is 0.2-2 parts by mass.

8. A semi-conductive shielding material, characterized in that: The semiconductive shielding material is made from the semiconductive shielding material composition described in any one of claims 1-7.

9. A method for preparing the semiconductive shielding material according to claim 8, characterized in that: The method comprises: S1. Under stirring conditions, the hydrogen bond acceptor and the hydrogen bond donor are first mixed to obtain a deep eutectic solvent; S2, performing a second mixing, extrusion, and granulation on the ethylene acrylic polymer, conductive carbon black, a low eutectic solvent, polyacrylate, an optional antioxidant, and an optional lubricant to obtain a granular material; S3, mixing the granular material with a cross-linking agent for absorption to obtain the semi-conductive shielding material.

10. The method according to claim 9, wherein: The stirring speed is 100-1000r / min; And / or, the first mixing is performed under heating conditions.

11. The method according to claim 10, wherein: The heating is performed so that the temperature of the first mixture is 50-100°C.

12. The method according to claim 9 or 10, wherein: The second mixing is carried out in an internal mixer; And / or, the temperature of the second mixing is 130-170° C., and the time of the second mixing is 10-30 min; And / or, in step S3, the absorption conditions include: the absorption temperature is 50-80° C., and the absorption time is 2-6 hours.

13. Use of the semiconductive shielding material composition according to any one of claims 1 to 7 or the semiconductive shielding material according to claim 8 in a high-voltage cable.

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