Thermoplastic allyl resin insulating material, preparation method thereof and cable

Abstract

The invention provides a thermoplastic propenyl resin insulating material, a preparation method thereof and a cable, and the thermoplastic propenyl resin insulating material comprises 70-90 wt% of a matrix phase composition and 10-30 wt% of an elastic phase composition based on the total weight of 100%, the matrix phase composition comprises polypropylene random copolymer resin and first insulating oil, the polypropylene random copolymer resin contains a nucleating agent, and M < z + 1 > / M < w > is greater than or equal to 4.0; the elastic phase composition comprises polyolefin elastic phase resin and second insulating oil, and in the polyolefin elastic phase resin, the content of o-dichlorobenzene soluble substances is larger than or equal to 50 wt%. The thermoplastic allyl resin insulating material has excellent thermal stability, mechanical property, electrical property and insulating property, and particularly has high breakdown strength, and the distribution of the breakdown strength is highly uniform; and the polymer resin and the insulating oil can be well and uniformly dispersed in the insulating material without leakage for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to a thermoplastic propylene-based resin insulating material, a preparation method thereof and a cable, and belongs to the technical field of cable materials. BACKGROUND

[0002] Cable insulation materials play a crucial role in power transmission. Thermoplastic propylene-based resins are a commonly used cable insulation material, which has excellent insulation performance, mechanical properties and thermal stability. However, the insulation performance and mechanical properties of traditional thermoplastic propylene-based resins have certain limitations in high temperature and high humidity environments.

[0003] In order to improve the performance of cable insulation materials, researchers have begun to explore the use of multiphase polymers to improve the performance of traditional thermoplastic propylene-based resins. Multiphase polymers are materials composed of two or more incompatible polymers, one of which is usually referred to as the matrix phase, and the other is referred to as the dispersed phase. In the prior art, the formation of multiphase polymers can be achieved by changing the formulation of the polymer, adding additives or changing the polymerization conditions.

[0004] There have been reports of using random copolymer polypropylene as a matrix phase of thermoplastic propylene-based resin compositions. Random copolymer polypropylene is a polymer composed of propylene and other monomers, which has good thermal stability and mechanical properties. This composition improves its insulation performance and mechanical properties by adding other functional monomers or additives to the random copolymer polypropylene.

[0005] Insulating oil can be used in cable materials to improve the insulation performance of cable insulation materials. Insulating oil can absorb and conduct heat during cable operation, play a role in cooling and heat dissipation, maintain the normal operating temperature of the cable; absorb the partial discharge energy in the cable, reduce the partial discharge phenomenon of the cable insulation material, improve the reliability and life of the cable; repair defects in the insulation material, etc. However, there is a risk of leakage or seepage of insulating oil. Moreover, the insulating oil used in the cable insulation layer may have a problem of uneven dispersion. This may be due to improper stirring or mixing during production. Unevenly dispersed insulating oil can significantly reduce the performance of the cable material, such as reduced insulation capacity. Therefore, appropriate measures must be taken during production to ensure uniform dispersion and no leakage of insulating oil to ensure the quality and performance of the cable.

[0006] The existing thermoplastic propylene-based resin composition still does not solve the above problems. In addition, the processing performance and heat resistance stability of the existing thermoplastic propylene-based resin composition need to be improved.

[0007] CN104364853A discloses a process for producing an energy cable comprising at least one electrically conductive core and at least one thermoplastic electrically insulating layer, the process comprising the steps of impregnating a thermoplastic material in subdivided solid form having a melting enthalpy equal to or lower than 70 J / g with a dielectric liquid, obtaining an impregnated thermoplastic material; feeding the impregnated thermoplastic material in subdivided solid form into a single screw extruder; extruding the impregnated thermoplastic material on at least one electrically conductive core so as to form at least one thermoplastic electrically insulating layer; whereby the impregnated thermoplastic material does not have to undergo any mechanical homogenization step in the molten state. The above process allows obtaining an energy cable having a high amount, for example higher than 10 wt%, of dielectric liquid within the electrically insulating layer, and without showing any morphological defects within the layer itself and without showing any defects in the extrusion process, even when the rotation speed of the extruder screw and therefore the production speed of the cable is high, for example higher than 20 m / min, for medium voltage cables.

[0008] The prior art has problems that the performance of the cable insulation layer is affected by the presence of the dielectric liquid which is intimately mixed with the polypropylene matrix, there is a problem of dielectric breakdown strength, especially for high voltage (HV) power transmission applications. The lubricating effect produced by the dielectric liquid causes the material to slide on the metal surfaces of the extruder barrel and screw. This sliding effect causes the extrusion process to be unstable, especially when the rotation speed of the extruder screw is high, and thus leads to poor quality of the insulation layer. In such an insulation layer, it is more likely that the formation of morphological defects (e.g. microvoids and microcracks) occurs, which can cause a decrease in dielectric strength. The patent application impregnates a thermoplastic material in subdivided solid form having a melting enthalpy equal to or lower than 70 J / g with a dielectric liquid, obtains an impregnated thermoplastic material, and feeds it into a single screw extruder for extrusion. By controlling process parameters such as impregnation temperature, time, etc., and the melting enthalpy of the material, etc., the thermal mechanical properties of the obtained insulation layer are maintained, and the dielectric liquid is prevented from bleeding out of the thermoplastic material. However, it does not consider the distribution problem of the insulating oil between different phases due to the difference in affinity and compatibility in the blend or multi-phase copolymer it uses, so there are still defects such as uneven distribution of breakdown strength and degradation of insulation performance caused by uneven distribution of cable insulation material.

[0009] CN112063054A discloses a thermoplastic resin composition and its application in medium voltage AC cable insulation layer, the thermoplastic resin composition contains a polypropylene multi-phase copolymer, the polypropylene multi-phase copolymer is obtained by polymerization of propylene, ethylene and optional α-olefin other than propylene, and the total content of ethylene structural units is 5-20 wt% based on the total content of the polypropylene multi-phase copolymer.

[0010] In the prior art, the multi-phase copolymer has the problem of phase separation, which is not conducive to electron migration; in addition, the cleanliness degree of the blending process is difficult to achieve, and the introduction of impurities will also affect the electrical properties of the blend. Moreover, in order to improve the properties of polypropylene such as breakdown strength, physical modification is required, which will introduce more impurities, thereby affecting the dielectric properties of the cable insulation layer; in addition, when the thickness of the cable insulation layer of high voltage reaches 8 mm or more, the internal and external cooling speeds of the cable insulation layer are inconsistent, the internal cooling speed is slow, and the external cooling speed is fast. The slow cooling of the thermoplastic polypropylene will cause large-sized crystalline bodies to appear, thereby causing topographical defects (such as micropores, etc.), and the topographical defects of the insulation layer will affect the breakdown resistance and dielectric constant of the cable insulation layer. In view of the above problems existing in the prior art, the present patent application aims to provide a polypropylene composition suitable for medium-voltage AC cables, which has excellent heat resistance, dielectric properties, breakdown strength and anti-aging properties. However, the lower rubber phase content of the multi-phase copolymer in this patent application will result in insufficient softness, and only the total content of ethylene structural units in the composition is given, without specifying the respective contents of ethylene in the matrix phase and the rubber phase. Therefore, the interface breakdown and interface polarization caused by the uneven composition of the two phases cannot be solved by adjusting the composition and structure of the composition, and thus there are still deficiencies in mechanical properties and electrical properties.

[0011] CN102597098A discloses a multi-phase polypropylene resin, comprising a propylene random copolymer matrix phase (A), and an ethylene-propylene copolymer rubber phase (B) dispersed in the matrix phase, wherein the multi-phase polypropylene resin has a MFR (2.16 kg, 230°C) of 1.0 to 100 g / 10 min, and a fraction soluble in p-xylene at 25°C (XCS fraction), which is present in the resin in an amount of 28 to 50 wt%, and a molecular weight distribution (Mw / Mn) of 1.0 to 4.0.

[0012] In view of the poor extrusion performance and poor impact resistance at low temperature still existing in the prior art, the present patent application aims to provide a polypropylene resin, which combines a propylene random copolymer as a matrix phase with a dispersed phase of an ethylene-propylene copolymer rubber containing a high content of propylene monomer units, and has a high degree of softness and excellent impact performance at low temperature, and also has a high melting temperature. However, the cable insulation material provided by this patent application uses a propylene random copolymer as a matrix phase, which reduces the electrical breakdown resistance of the composition (especially at high temperatures), and the mixing of a high-soft rubber phase will cause interphase defects during cable processing, forming breakdown weak points, thereby causing deterioration of the overall insulation performance.

[0013] Therefore, it has become a technical problem urgently to be solved in the art to provide a new type of thermoplastic propylene-based resin insulation material, a preparation method thereof and a cable. SUMMARY

[0014] To solve the above-mentioned shortcomings and deficiencies, the present application aims to provide a thermoplastic propylene-based resin insulation material, a preparation method thereof and a cable.

[0015] To achieve the above-mentioned aims, in one aspect, the present application provides a thermoplastic propylene-based resin insulation material, which comprises 70-90wt% of a matrix phase composition and 10-30wt% of an elastomer phase composition, based on the total weight of the thermoplastic propylene-based resin insulation material being 100%.

[0016] The matrix phase composition comprises a random copolymer polypropylene-based resin and a first insulation oil, the random copolymer polypropylene-based resin contains a nucleating agent, and M z+1 / M w ≥4.0, preferably, M z+1 / M w ≥5.0.

[0017] The elastomer phase composition comprises a polyolefin elastomer phase resin and a second insulation oil, the content of ortho-dichlorobenzene-soluble substance in the polyolefin elastomer phase resin is ≥50wt%.

[0018] As a specific embodiment of the above-mentioned thermoplastic propylene-based resin insulation material of the present application, the thermoplastic propylene-based resin insulation material comprises 75-85wt% of the matrix phase composition and 15-25wt% of the elastomer phase composition, based on the total weight of the thermoplastic propylene-based resin insulation material being 100%.

[0019] As a specific embodiment of the above-mentioned thermoplastic propylene-based resin insulation material of the present application, the random copolymer polypropylene-based resin is obtained by polymerization reaction of raw materials comprising propylene and ethylene in the presence of a nucleating agent, and the content of the nucleating agent in the random copolymer polypropylene-based resin is 0.05-0.2wt%, based on the total weight of the random copolymer polypropylene-based resin being 100%.

[0020] As a specific embodiment of the above-mentioned thermoplastic propylene-based resin insulation material of the present application, the nucleating agent comprises a carboxylate nucleating agent and / or a phosphate nucleating agent, and preferably is a carboxylate nucleating agent. The carboxylate nucleating agent can be selected from one or both of sodium benzoate and hydroxy aluminum p-t-butylbenzoate; the phosphate nucleating agent can be selected from any one of sodium 2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate and aluminum bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)] phosphate.

[0021] In this invention, nucleating agents can reduce the grain size in the crystalline phase and further improve the electrical breakdown resistance and dielectric strength of insulating materials. Nucleating agents can provide a nucleation site during the polymerization reaction, promoting the aggregation of monomer molecules around it and the formation of new polymer chains. Nucleating agents can accelerate the crystallization rate and also regulate the crystalline structure and morphology of the polymer.

[0022] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the content of ethylene structural units is 3-6 wt% based on the total weight of the random copolymer polypropylene-based resin as 100%.

[0023] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the raw material further includes α-olefins, that is, the thermoplastic propylene-based resin insulating material contains ethylene units, propylene units and α-olefin units, and the content of α-olefin structural units is 1-3 wt% based on the total weight of the random copolymer polypropylene-based resin as 100%.

[0024] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the α-olefin includes one or a combination of several of butene, hexene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, preferably 1-butene.

[0025] Polymers are long-chain substances formed by chemical bonds between repeating units (monomers). Unlike low-molecular-weight compounds, polymers do not have a fixed molecular weight; instead, they are mixtures of homologues with different molecular weights. Therefore, the molecular weight of a polymer is an average value, and its distribution is not fixed.

[0026] Chain length is typically expressed as the molecular weight of a polymer chain, which is related to the relative molecular weight of the monomers and the number of monomers in the chain. However, all synthetic polymers are polydisperse, containing polymer chains of varying lengths. Therefore, the molecular weight of a polymer is not a single value, but rather a range of polymer chain lengths and molecular weights. Consequently, the molecular weight of a polymer must be described by calculating the average molecular weight of all polymer chains in the sample.

[0027] In this invention, M w This is the weight-average molecular weight, relative to the number-average molecular weight M. n When determining the average molecular weight, the molecular weight of the single chain is compared with M. w The contribution of M is also taken into account. The greater the quality of the chain, the greater the contribution to M. w The greater their contribution, the greater their contribution.

[0028] In this invention, M zZ-mean molecular weight is a method for calculating the average molecular weight. The formula is Mz = Σ(Ni × Mi). 3 ) / Σ(Ni×Mi 2 ), where Ni refers to the number of polymer molecules with a molecular weight of Mi present in the sample. M z+1 It is the Z+1 average molecular weight, and its calculation formula is M. z+1 =Σ(Ni×Mi 4 ) / Σ(Ni×Mi 3 ).

[0029] In the thermoplastic propylene-based resin insulating material provided by this invention, the M of the random copolymer polypropylene-based resin... z+1 / M w Within the molecular weight distribution range of ≥4.0, the system contains a large number of long-chain macromolecules, which is conducive to the formation of a dense chain entanglement network, thereby significantly improving the electrical breakdown strength of thermoplastic acrylic resin insulating materials and cable insulation layers made therefrom.

[0030] The thermoplastic propylene-based resin insulating material provided by this invention uses random copolymer polypropylene-based resin as the matrix phase, achieving a balance between mechanical and electrical properties at relatively high operating temperatures. Furthermore, this thermoplastic propylene-based resin insulating material has a multiphase structure, i.e., it is a multiphase polymer. Multiphase polymers containing random copolymer polypropylene-based resin have high crystallinity. This crystalline structure promotes the orderly arrangement of polymer molecules, increasing the material's strength and rigidity. This orderly arrangement also effectively prevents the propagation of electric fields within the material, thereby improving breakdown strength. The multiphase structure of this invention exhibits good interfacial effects, further enhancing the material's interfacial strength and resistance to electric field breakdown.

[0031] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the polyolefin elastic phase resin includes one or a combination of several of the following: ethylene propylene copolymer, ethylene butene copolymer, ethylene hexene copolymer, ethylene octene copolymer, propylene butene copolymer, propylene hexene copolymer, and polystyrene butadiene copolymer.

[0032] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the content of the first insulating oil is 2.5-10 wt%, based on the total weight of the random copolymer polypropylene-based resin as 100%.

[0033] In one specific embodiment of the thermoplastic propylene-based resin insulating material of the present invention, the content of the second insulating oil is 5-15 wt% based on 100% of the total weight of the polyolefin elastic phase resin. Alternatively, based on 100% of the total weight of the thermoplastic propylene-based resin insulating material, the total content of the first insulating oil and the second insulating oil is 3.5-5 wt%.

[0034] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the first insulating oil and the second insulating oil are selected from one or more of the following: cycloalkyl oil, chain alkyl oil, polyisobutylene oil, naphthenic oil, aromatic oil, α-olefin oil, and silicone oil. Preferably, the first insulating oil and the second insulating oil are both dibenzyltoluene (DBT).

[0035] The first and second insulating oils used in this invention can further increase the breakdown strength and dielectric properties of thermoplastic propylene-based resin insulating materials. Furthermore, the first and second insulating oils have good compatibility with random copolymer polypropylene-based resin and polyolefin elastic phase resin, respectively, which can achieve uniform diffusion of random copolymer polypropylene-based resin and polyolefin elastic phase resin inside the insulating material.

[0036] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the thermoplastic propylene-based resin insulating material further includes additives, which include one or a combination of antioxidants, voltage stabilizers, and processing aids.

[0037] As a specific embodiment of the thermoplastic propylene-based resin insulating material described above in this invention, the content of antioxidant is 0.01-1 wt%, preferably 0.1-0.5 wt%, and the content of voltage stabilizer is 0.01-5 wt%, preferably 0.1-2 wt%, based on 100% of the total weight of the thermoplastic propylene-based resin insulating material.

[0038] In this invention, when the thermoplastic acrylic resin insulating material further contains additives, the amount of each component can be adjusted within the numerical range of the matrix phase composition, elastic phase composition, and additive content, but the sum of the contents of each component must be 100%.

[0039] In this invention, antioxidants can improve the long-term stability of insulating materials. As a specific embodiment of the thermoplastic acrylic resin insulating material described above, the antioxidant can be selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dihydroxybenzyl)benzene, etc. One or a combination of several of the following: (-dimethylbenzyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, N,N-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, octadecyl 3,3-thiodipropionate, and β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester.

[0040] In this invention, the voltage stabilizer can further improve the electrical breakdown resistance and dielectric strength of the insulating material. It can be selected from substituted benzophenone voltage stabilizers, wherein the substituent can be one or a combination of several of alkyl, aryl, alkoxy, and aryloxy groups. It can also be selected from benzoyl derivative voltage stabilizers, such as one or a combination of several of 4-methoxybenzoyl, 4-hydroxybenzoyl, 4,4'-bis(dioctylamino)benzoyl, 4,4'-dioctylaminobenzoyl, p-anezoyl, 4,4'-dihydroxybenzoyl, 4,4'-di(dodecyloxy)benzoyl, 4,4'-di(undec-10-enoxy)benzoyl, 4-hydroxybenzoyl, 4-dodecyloxybenzoyl, and 4-undec-10-enoxybenzoyl.

[0041] On the other hand, the present invention also provides a method for preparing the above-described thermoplastic acrylic resin insulating material, wherein the preparation method includes:

[0042] Step (1): Mix the random copolymer polypropylene-based resin and the first insulating oil evenly to obtain the matrix phase composition;

[0043] Step (2): Mix the polyolefin elastic phase resin and the second insulating oil evenly to obtain an elastic phase composition;

[0044] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module and then extruded after being mixed by at least one micro-nano stacked mixing module to obtain the thermoplastic propylene resin insulating material.

[0045] As a specific embodiment of the preparation method described above in this invention, when the thermoplastic propylene resin insulating material further includes one or more of the following additives: antioxidant, voltage stabilizer and processing aid, the additive can be added alone in step (1), step (2) or step (3), or in any two of the steps, or in all three steps at the same time.

[0046] As a specific embodiment of the preparation method described above in this invention, in step (1), the uniform mixing can be achieved in a high-speed mixer, and the mixing time can be 5-10 min.

[0047] As a specific embodiment of the preparation method described above in this invention, in step (2), the uniform mixing can be achieved in a high-speed mixer, and the mixing time can be 5-10 min.

[0048] As a specific embodiment of the preparation method described above in this invention, the micro-nano stacked mixing module includes one or a combination of several of the following: a spiral micro-mixer, a Y-type micro-mixer, a T-type micro-mixer, and a reversing micro-mixer, preferably a spiral micro-mixer.

[0049] In one specific embodiment of the preparation method described above in this invention, the number of micro-nano stacked hybrid modules is 4-10.

[0050] In step (3) of the preparation method described above, the matrix phase composition and the elastic phase composition are mixed using a micro-nano multilayer mixing module. The micro-nano multilayer mixing module utilizes microfluidics principles to effectively mix, disperse, and react two or more polymer materials at the microscale, thereby increasing the reaction rate, enhancing the reaction effect, and improving the performance of the final product.

[0051] This invention utilizes a matrix phase composition comprising random copolymer polypropylene-based resin, and controls the content and composition of the matrix phase composition and the elastic phase composition, combined with the preparation method described above, to obtain an insulating material with high electrical breakdown resistance and highly uniform breakdown strength distribution. Furthermore, through the preparation method described above, the resin and insulating oil in the insulating material can be well and uniformly dispersed, preventing leakage over extended periods.

[0052] In another aspect, the present invention also provides a cable, wherein the insulation layer of the cable is made of the thermoplastic acrylic resin insulation material described above.

[0053] In one specific embodiment of the cable described above in this invention, the cable is a thermoplastic high-voltage cable.

[0054] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0055] The thermoplastic acrylic resin insulating material provided by the present invention has excellent thermal stability, mechanical properties, electrical properties and insulation properties, especially high breakdown strength and highly uniform breakdown strength distribution.

[0056] In the thermoplastic propylene-based resin insulating material provided by the present invention, the polymer resin (random copolymer polypropylene-based resin and polyolefin elastic phase resin) and the insulating oil (first insulating oil and second insulating oil) can be well and uniformly dispersed in the insulating material, and there is no leakage over a long period of time. When the insulating material is used as the insulating layer material of the cable, it can meet the insulation requirements of the cable under high voltage environment.

[0057] The thermoplastic propylene-based resin insulation material provided by this invention has good extrusion processing performance, and the preparation process is simple and environmentally friendly. Detailed Implementation

[0058] It should be noted that the term "comprising" and any variations thereof in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0059] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0060] In this invention, unless otherwise specified, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this invention, and "0-5" is simply a shortened representation of these numerical combinations.

[0061] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0062] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0063] In this invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0064] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the appendices and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0065] Evaluation and analysis methods:

[0066] AC breakdown strength / DC breakdown strength: Determined according to the method specified in GB / T 1408-2006, with an output AC voltage of 0-100kV, using 10mm diameter ball-to-ball copper electrodes, a voltage ramp rate of 2kV / s, a thin film sample diameter of 15cm, and a thickness of 0.20mm. Each sample group has at least 10 measurement points. Both the test sample and the electrode are immersed in silicone oil (treated in a 70℃ vacuum oven for 24h before testing) to prevent surface discharge.

[0067] Breakdown strength distribution index: The AC breakdown strength / DC breakdown strength tests were performed at different locations on the thin film sample, and the breakdown voltage values ​​at different locations were recorded. The Weibull distribution was used to analyze the DC breakdown field strength / AC breakdown field strength test results. The probability density function of the two-parameter Weibull probability distribution used in the Weibull distribution can be expressed as shown in Equation 1):

[0068]

[0069] In Equation 1), parameter P is the cumulative probability value of sample breakdown, E is the random variable of DC breakdown field strength / AC breakdown field strength of sample, β is the shape parameter, representing the reciprocal of data dispersion, serving as the breakdown strength distribution index, and E0 is the scale parameter of the Weibull distribution, representing the breakdown field strength value corresponding to a cumulative breakdown probability P of 63.2%. Usually, E0 is taken as the average breakdown field strength of the test sample.

[0070] Molecular weight distribution: Molecular weight distribution is expressed as Z+1 average molecular weight (M z+1 ) and weight-average molecular weight (M W The ratio between ) was determined. The equipment used in the test was as follows: the sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / ml, and the resulting solution was tested using high-temperature gel permeation chromatography (GPC). The test temperature was 150℃, the solution flow rate was 1.0 ml / min, and the molecular weight of polystyrene was used as an internal reference to establish a standard curve. The molecular weight and molecular weight distribution of the sample were calculated based on the elution time.

[0071] Crystallization elution fractionation of solubles, i.e., o-dichlorobenzene solubles: The soluble fraction of the polymer was analyzed using a crystallization elution fractionation (CEF) system from PolymerChar. The experimental procedure was as follows: The polymer was dissolved in o-dichlorobenzene at 160°C. After 120 minutes, the temperature was lowered to 95°C at a rate of 30°C / min, and then crystallized to 35°C at a rate of 2°C / min. Simultaneously, the o-dichlorobenzene was pumped at a rate of 0.05 mL / min and the column was slowly rinsed. After crystallization, the temperature was increased to 150°C at a rate of 4°C / min and 1 mL / min. The sample information during the elution process was recorded using an IR-5 infrared detector to obtain the crystallization elution fractionation curve and the soluble content.

[0072] Tensile fracture strain: tested according to GB / T 1040.1-2019 standard.

[0073] Example 1

[0074] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX1, which is prepared by a method including the following specific steps:

[0075] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 3.5 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0076] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 3 wt%, the content of sodium benzoate is 0.2 wt%, and M...z+1 / M w =5.0.

[0077] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 7.5 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0078] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0079] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 85:15, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0080] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0081] Example 2

[0082] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX2, which is prepared by a method including the following specific steps:

[0083] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 5 parts by weight of dibenzyltoluene in a high-speed mixer for 5 minutes to obtain a matrix phase composition;

[0084] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 5.8 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =4.5.

[0085] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 12.5 parts by weight of dibenzyl toluene in a high-speed mixer for 5 minutes to obtain an elastic phase composition;

[0086] In the crystallization rinsing fraction (CEF) of the ethylene-propylene copolymer resin, the content of the soluble component (o-dichlorobenzene soluble component) is 55%.

[0087] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with micro-nano stacked mixing modules at a weight ratio of 75:25, and then extruded after being mixed by a spiral micro-mixer with three micro-nano stacked mixing modules.

[0088] Step (4): Cool and pelletize to obtain the thermoplastic propylene resin insulation material.

[0089] Example 3

[0090] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX3, which is prepared by a method including the following specific steps:

[0091] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 10 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0092] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 6 wt%, the content of sodium benzoate is 0.05 wt%, and M... z+1 / M w =5.0.

[0093] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 15 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0094] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of ethylene propylene copolymer resin is 60%.

[0095] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 80:20, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0096] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0097] Example 4

[0098] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX4, which is prepared by a method including the following specific steps:

[0099] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 5 parts by weight of dibenzyltoluene in a high-speed mixer for 5 minutes to obtain a matrix phase composition;

[0100] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 5.8 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =5.5.

[0101] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 12.5 parts by weight of dibenzyl toluene in a high-speed mixer for 5 minutes to obtain an elastic phase composition;

[0102] In the crystallization rinsing fraction (CEF) of the ethylene-propylene copolymer resin, the content of the soluble component (o-dichlorobenzene soluble component) is 55%.

[0103] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with micro-nano stacked mixing modules at a weight ratio of 75:25, and then extruded after being mixed by a spiral micro-mixer with three micro-nano stacked mixing modules.

[0104] Step (4): Cool and pelletize to obtain the thermoplastic propylene resin insulation material.

[0105] Example 5

[0106] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX5, which is prepared by a method including the following specific steps:

[0107] Step (1): Mix 100 parts by weight of ethylene-propylene-1-butene copolymer resin and 3.5 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0108] In the ethylene-propylene-1-butene copolymer resin, based on the total weight of the ethylene-propylene-1-butene copolymer resin as 100%, the content of ethylene structural units is 3 wt%, the content of 1-butene structural units is 2 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =5.0.

[0109] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 7.5 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0110] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0111] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 85:15, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0112] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0113] Example 6

[0114] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX6, which is prepared by a method including the following specific steps:

[0115] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 3.5 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0116] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 3 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =5.0.

[0117] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 7.5 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0118] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0119] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with micro-nano stacked mixing modules at a weight ratio of 85:15, along with antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (0.1 wt% based on 100% of the total weight of the thermoplastic propylene resin insulation material) and voltage stabilizer 4-methoxybenzoyl (0.5 wt% based on 100% of the total weight of the thermoplastic propylene resin insulation material). The mixture is then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0120] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0121] Example 7

[0122] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX7, which is prepared by a method including the following specific steps:

[0123] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 5 parts by weight of dibenzyltoluene in a high-speed mixer for 5 minutes to obtain a matrix phase composition;

[0124] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 5.8 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / Mw =5.5.

[0125] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 12.5 parts by weight of dibenzyl toluene in a high-speed mixer for 5 minutes to obtain an elastic phase composition;

[0126] In the crystallization rinsing fraction (CEF) of the ethylene-propylene copolymer resin, the content of the soluble component (o-dichlorobenzene soluble component) is 55%.

[0127] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with micro-nano stacked mixing modules at a weight ratio of 75:25, along with antioxidant 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (0.5 wt% based on 100% of the total weight of the thermoplastic acrylic resin insulation material) and voltage stabilizer 4,4'-dioctylaminobenzoyl (2 wt% based on 100% of the total weight of the thermoplastic acrylic resin insulation material). The mixture is then extruded after being mixed by a spiral micro-mixer with three micro-nano stacked mixing modules.

[0128] Step (4): Cool and pelletize to obtain the thermoplastic propylene resin insulation material.

[0129] Example 8

[0130] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX8, which is prepared by a method including the following specific steps:

[0131] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 3.5 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0132] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 3 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =5.0.

[0133] Step (2): Mix 100 parts by weight of propylene butene copolymer resin and 7.5 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0134] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0135] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 85:15, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0136] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0137] Example 9

[0138] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX9, which is prepared by a method including the following specific steps:

[0139] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 3.5 parts by weight of dibenzyltoluene in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0140] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 3 wt%, the content of sodium 2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphate is 0.2 wt%, and M... z+1 / M w =5.0.

[0141] Step (2): Mix 100 parts by weight of ethylene propylene copolymer resin and 7.5 parts by weight of dibenzyl toluene in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0142] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0143] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 85:15, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0144] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0145] Example 10

[0146] This embodiment provides a thermoplastic acrylic resin insulating material, denoted as EX10, which is prepared by a method including the following specific steps:

[0147] Step (1): Mix 100 parts by weight of random copolymer polypropylene resin and 3.5 parts by weight of naphthenic oil Nytex820 in a high-speed mixer for 10 min to obtain a matrix phase composition;

[0148] In the random copolymer polypropylene-based resin, based on the total weight of the random copolymer polypropylene-based resin as 100%, the content of ethylene structural units is 3 wt%, the content of sodium benzoate is 0.2 wt%, and M... z+1 / M w =5.0.

[0149] Step (2): Mix 100 parts by weight of ethylene-propylene copolymer resin and 7.5 parts by weight of naphthenic oil Nytex820 in a high-speed mixer for 10 min to obtain an elastic phase composition;

[0150] The soluble component (o-dichlorobenzene soluble component) content in the crystallization wash fraction (CEF) of the ethylene propylene copolymer resin is 65%.

[0151] Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module at a weight ratio of 85:15, and then extruded after being mixed by a spiral micro-mixer with two micro-nano stacked mixing modules.

[0152] Step (4): Cool and pelletize to obtain thermoplastic acrylic resin insulation material.

[0153] Comparative Example 1

[0154] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE1, which differs from Example 1 only in the M of the random copolymer polypropylene resin used. z+1 / M w Unlike in this comparative example, M z+1 / M w =3.5.

[0155] Comparative Example 2

[0156] This comparative example provides a thermoplastic propylene-based resin insulating material, denoted as CE2. The only difference between it and Example 2 is the content of soluble components in the crystallization wash fraction (CEF) of the ethylene-propylene copolymer resin. In this comparative example, the content is 45%.

[0157] Comparative Example 3

[0158] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE3. The only difference between it and Example 1 is the weight ratio of the matrix phase composition to the elastic phase composition. In this comparative example, the weight ratio of the matrix phase composition to the elastic phase composition is 65:35.

[0159] Comparative Example 4

[0160] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE4, which differs from Example 2 only in the use of a different twin-screw extruder. In this comparative example, a conventional twin-screw extruder is used to mix the matrix phase composition and the elastic phase composition.

[0161] Comparative Example 5

[0162] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE5, which differs from Example 2 only in the extruder used. In this comparative example, a single-screw extruder is used to mix the matrix phase composition and the elastic phase composition.

[0163] Comparative Example 6

[0164] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE6, which differs from Example 2 only in that a mixer is used in this comparative example to mix the matrix phase composition and the elastic phase composition.

[0165] Comparative Example 7

[0166] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE7, which differs from Example 1 only in that it does not use sodium benzoate nucleating agent.

[0167] Comparative Example 8

[0168] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE8, which differs from Example 1 only in that the matrix phase composition in this comparative example does not contain dibenzyltoluene.

[0169] Comparative Example 9

[0170] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE9, which differs from Example 1 only in that the elastic phase composition in this comparative example does not contain dibenzyltoluene.

[0171] Comparative Example 10

[0172] This comparative example provides a thermoplastic acrylic resin insulating material, denoted as CE10. The only difference between it and Example 1 is the weight ratio of the matrix phase composition to the elastic phase composition. In this comparative example, the weight ratio of the matrix phase composition to the elastic phase composition is 95:5.

[0173] Test case

[0174] In this test example, the AC breakdown strength, AC breakdown strength at 30°C, AC breakdown strength at 90°C, AC breakdown strength distribution index at 30°C, AC breakdown strength distribution index at 90°C, DC breakdown strength at 30°C, DC breakdown strength distribution index at 90°C, DC breakdown strength distribution index at 30°C, DC breakdown strength distribution index at 90°C, and tensile fracture strain of EX1-EX10 provided in Examples 1-10 and CE1-CE10 provided in Comparative Examples 1-10 were tested according to the evaluation and analysis method shown above. The experimental results are shown in Table 1 below.

[0175] Table 1

[0176]

[0177]

[0178] As can be seen from Table 1 above, EX1-EX10 provided in Examples 1-10 of the present invention exhibit excellent AC breakdown strength at 30°C, AC breakdown strength at 90°C, AC breakdown strength distribution index at 30°C, AC breakdown strength distribution index at 90°C, DC breakdown strength at 30°C, DC breakdown strength distribution index at 90°C, DC breakdown strength distribution index at 30°C, DC breakdown strength distribution index at 90°C, and tensile fracture strain. In contrast, CE1-CE10 provided in Comparative Examples 1-10 show poor performance in many aspects. This indicates that the thermoplastic acrylic resin insulating material provided in the embodiments of the present invention can still maintain high electrical, mechanical, and insulating properties at high temperatures, especially with high breakdown strength and highly uniform breakdown strength distribution.

[0179] Compared to Example 2, M in Example 4 of the present invention z+1 / M w The breakdown strength is higher, reaching 5.5. Correspondingly, the breakdown strength distribution index and tensile fracture strain of EX4 provided in Example 4 are all superior to those of EX2 provided in Example 2. This indicates that the present invention improves M. z+1 / M w This makes it easier to obtain thermoplastic propylene-based resin insulation materials with excellent insulation and mechanical properties.

[0180] Compared to Example 1, the random copolymer polypropylene-based resin used in Example 5 of the present invention is an ethylene-propylene-1-butene copolymer resin containing 1-butene structural units. The breakdown strength and breakdown strength distribution index of EX5 provided in Example 5 are comparable to those of EX1 provided in Example 1, while its tensile breaking strain is slightly higher than that of EX1 provided in Example 1, that is, its mechanical properties are superior.

[0181] Compared to Example 1, Example 6 of the present invention uses antioxidants and voltage stabilizers. The breakdown strength and breakdown strength distribution index of EX6 provided in Example 6 are better than those of EX1 provided in Example 1. At the same time, its tensile fracture strain is also slightly better than that of EX1 provided in Example 1, that is, its mechanical properties are better.

[0182] Compared to Example 4, Example 7 of the present invention uses antioxidants and voltage stabilizers. The breakdown strength and breakdown strength distribution index of EX7 provided in Example 7 are better than those of EX4 provided in Example 4. At the same time, its tensile fracture strain is also slightly better than that of EX4 provided in Example 4, that is, its mechanical properties are better.

[0183] Compared to Example 1, the polyolefin elastic phase resin used in Example 8 of this invention is propylene butene copolymer resin, and the nucleating agent used in Example 9 is sodium 2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphate. The breakdown strength and breakdown strength distribution index of EX8-EX9 provided in Examples 8-9 are comparable to those of EX1 provided in Example 1. However, the tensile fracture strain of both is significantly worse than that of EX1 provided in Example 1, that is, the mechanical properties of both are worse.

[0184] Compared to Example 1, the first and second insulating oils used in Example 10 of the present invention are both naphthenic oil Nytex 820. The breakdown strength, breakdown strength distribution index and tensile breaking strain of EX10 provided in Example 1 are inferior to those of EX1 provided in Example 1. This shows that the present invention can obtain thermoplastic propylene resin insulating materials with better electrical, mechanical and insulating properties by using dibenzyltoluene as the first and second insulating oils.

[0185] Compared to Example 1, the random copolymer polypropylene-based resin used in Comparative Example 1 has a higher M content. z+1 / M w The value is only 3.5, which is outside the scope of protection claimed in this application. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of the CE1 provided are significantly inferior to those of EX1 provided in Example 1. This indicates that the present invention must control the M of the random copolymer polypropylene-based resin. z+1 / M w A value of ≥4.0 is required to obtain thermoplastic propylene-based resin insulation materials with excellent insulation and mechanical properties.

[0186] Compared to Example 2, the soluble component content in the crystallization wash fraction (CEF) of the ethylene-propylene copolymer resin used in Comparative Example 2 is only 45%, which is not within the scope of protection claimed in this application. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of CE2 provided by Comparative Example 2 are significantly inferior to those of EX2 provided by Example 2. This indicates that the present invention must control the content of o-dichlorobenzene solubles in the polyolefin elastic phase resin to ≥50wt% in order to obtain a thermoplastic propylene-based resin insulating material with excellent insulation and mechanical properties.

[0187] Compared to Example 1, the weight ratio of the matrix phase composition to the elastic phase composition in Comparative Example 3 is 65:35, which is not within the scope of protection claimed in this application. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of CE3 provided by Comparative Example 3 are significantly inferior to those of EX1 provided by Example 1. This indicates that the present invention must control the total weight of the thermoplastic acrylic resin insulating material to be 100%, containing 70-90 wt% of the matrix phase composition and 10-30 wt% of the elastic phase composition, in order to obtain a thermoplastic acrylic resin insulating material with excellent insulation and mechanical properties.

[0188] Compared to Example 1, the weight ratio of the matrix phase composition to the elastic phase composition in Comparative Example 10 is 95:5, which is not within the scope of protection claimed in this application. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of CE10 provided by Comparative Example 1 are significantly inferior to those of EX1 provided by Example 1. This indicates that the present invention must control the total weight of the thermoplastic propylene resin insulating material to be 100%, containing 70-90 wt% of the matrix phase composition and 10-30 wt% of the elastic phase composition, in order to obtain a thermoplastic propylene resin insulating material with excellent insulation and mechanical properties.

[0189] Compared to Example 2, Comparative Examples 4-6 used a conventional twin-screw extruder, a single-screw extruder, and a mixer, respectively, to mix the matrix phase composition and the elastic phase composition. A twin-screw extruder with a micro-nano layered mixing module was not used. As shown in Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of CE4-CE6 provided by these comparative examples were significantly inferior to EX2 provided in Example 2. This indicates that the present invention requires the use of a twin-screw extruder with a micro-nano layered mixing module to mix the matrix phase composition and the elastic phase composition when preparing thermoplastic propylene-based resin insulating materials to obtain thermoplastic propylene-based resin insulating materials with excellent insulation and mechanical properties.

[0190] Compared to Example 1, Comparative Example 7 did not use a nucleating agent. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index, and tensile fracture strain of CE7 provided by Comparative Example 7 are significantly inferior to those of EX1 provided by Example 1. This indicates that the present invention can obtain thermoplastic propylene resin insulating materials with superior electrical, mechanical, and insulating properties by using a nucleating agent.

[0191] Compared to Example 1, no insulating oil was added to the matrix phase composition and the elastic phase composition in Comparative Examples 8-9, respectively. As can be seen from Table 1, the breakdown strength, breakdown strength distribution index and tensile fracture strain of CE8 and CE9 provided by them are significantly worse than those of EX1 provided by Example 1. This indicates that the present invention must add insulating oil to both the matrix phase composition and the elastic phase composition to obtain thermoplastic propylene resin insulating materials with excellent insulation and mechanical properties.

[0192] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A thermoplastic acrylic resin insulating material, characterized in that, Based on 100% of the total weight of the thermoplastic acrylic resin insulating material, it contains 70-90 wt% of a matrix phase composition and 10-30 wt% of an elastic phase composition. The matrix composition comprises a random copolymer polypropylene resin and a first insulating oil, wherein the random copolymer polypropylene resin contains a nucleating agent, and M z+1 / M w ≥4.0; The elastic phase composition comprises a polyolefin elastic phase resin and a second insulating oil, wherein the content of o-dichlorobenzene solubles in the polyolefin elastic phase resin is ≥50wt%.

2. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, The nucleating agent content is 0.05-0.2 wt% based on the total weight of the random copolymer polypropylene-based resin as 100%.

3. The thermoplastic acrylic resin insulating material according to claim 2, characterized in that, The nucleating agents include carboxylate nucleating agents and / or phosphate nucleating agents.

4. The thermoplastic acrylic resin insulating material according to any one of claims 1-3, characterized in that, The content of ethylene structural units in the random copolymer polypropylene-based resin is 3-6 wt%, which is 100% of the total weight of the resin.

5. The thermoplastic acrylic resin insulating material according to claim 4, characterized in that, The α-olefin structural unit content is 1-3 wt% of the total weight of the random copolymer polypropylene-based resin, which is 100%.

6. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, The polyolefin elastic phase resin includes one or a combination of several of the following: ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, propylene-butene copolymer, propylene-hexene copolymer, and polystyrene-butadiene copolymer.

7. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, The content of the first insulating oil is 2.5-10 wt%, based on the total weight of the random copolymer polypropylene resin as 100%.

8. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, The content of the second insulating oil is 5-15 wt%, based on 100% of the total weight of the polyolefin elastic phase resin.

9. The thermoplastic acrylic resin insulating material according to any one of claims 1, 7-8, characterized in that, The first insulating oil and the second insulating oil are the same as or different from one or a combination of several of the following: naphthenic oil, alkyl oil, polyisobutylene oil, naphthenic oil, aromatic oil, α-olefin oil and silicone oil.

10. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, The thermoplastic acrylic resin insulating material further includes additives, which include one or a combination of antioxidants, voltage stabilizers and processing aids.

11. The thermoplastic acrylic resin insulating material according to claim 1, characterized in that, Based on the total weight of the thermoplastic acrylic resin insulation material as 100%, the content of antioxidant is 0.01-1wt%, and the content of voltage stabilizer is 0.01-5wt%.

12. A method for preparing the thermoplastic acrylic resin insulating material according to any one of claims 1-11, characterized in that, The preparation method includes: Step (1): Mix the random copolymer polypropylene-based resin and the first insulating oil evenly to obtain the matrix phase composition; Step (2): Mix the polyolefin elastic phase resin and the second insulating oil evenly to obtain an elastic phase composition; Step (3): The matrix phase composition and the elastic phase composition are placed in a twin-screw extruder with a micro-nano stacked mixing module and then extruded after being mixed by at least one micro-nano stacked mixing module to obtain the thermoplastic propylene resin insulating material.

13. The preparation method according to claim 12, characterized in that, The micro-nano stacked mixing module includes one or a combination of several of the following: helical micro-mixer, Y-type micro-mixer, T-type micro-mixer, and commutator micro-mixer.

14. The preparation method according to claim 12 or 13, characterized in that, The number of micro-nano stacked hybrid modules is 4-10.

15. A cable, characterized in that, The insulation layer of the cable is made of the thermoplastic acrylic resin insulation material as described in any one of claims 1-11.

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