Modified PVC cable material and preparation method thereof

Abstract

The invention relates to a modified PVC cable material and a preparation method thereof, and relates to the technical field of polyvinyl chloride cable materials, the modified PVC cable material comprises the following components by weight: 95-105 parts of a modified polyvinyl chloride base material, 25-40 parts of a filler, 35-45 parts of a plasticizer, 8-15 parts of a flame retardant, 5-12 parts of a stabilizer, 0.8-1.5 parts of an ultraviolet light absorber, 0.5-2 parts of an antioxidant and 1-2 parts of a lubricant. On the basis of an existing PVC cable material formula, a CO2 supercritical fluid process is mainly adopted, and specific hyperbranched epoxy resin and ionic liquid are introduced to realize physical-chemical combined modification on a PVC base material, so that the low temperature resistance, the mechanical property and the like of the PVC cable material are effectively improved; therefore, the cable material meets the use requirement of being applied to extremely cold environments such as-50 DEG C or below for a long time, and overcomes the defects of the existing PVC cable material.

Description

Technical Field

[0001] The present invention relates to the technical field of polyvinyl chloride cable materials, and in particular to a modified PVC cable compound and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC), as the second largest general-purpose resin in the world after polyethylene, has been widely used in the cable field due to its low price, good mechanical properties, strong weather resistance, excellent electrical insulation, and outstanding geometric stability. However, with the rapid development of modern power systems and communication networks, the performance requirements for cable compounds are getting higher and higher, especially for applications in extreme environmental conditions, such as extremely cold regions, where this demand is particularly prominent.

[0003] At present, traditional PVC cable compounds have inherent limitations in low-temperature resistance and mechanical properties, and are difficult to meet the usage requirements of these special environments. The reason is that there are many active centers distributed in the molecular chain of ordinary PVC materials, which makes their cold resistance and tensile resistance relatively poor. In a low-temperature environment, the movement ability of the PVC molecular chain is severely restricted, and the material becomes brittle and hard, and is easily broken under external force impact. In addition, over time, PVC molecules are prone to aging, further leading to the decline of the cable material performance.

[0004] It is particularly noteworthy that in regions with extremely large temperature differences between day and night, such as in the north, Russia, and northern Europe, the daytime temperature may be as high as above -10°C, while at night, the temperature may drop sharply to below -40°C, or even as low as -60°C. In such an extreme low-temperature environment, if the low-temperature impact strength and embrittlement temperature of the cable compound do not meet the requirements, the cable is extremely likely to be damaged by low temperature during the laying process, thus severely shortening the service life of the cable and threatening the safe operation of the power system.

[0005] Therefore, it is particularly important to develop a modified PVC cable compound with excellent low-temperature resistance and mechanical properties. This can not only meet the usage requirements in extreme environments, but also effectively improve the reliability and durability of the cable, providing strong support for the stable development of modern power systems and communication networks. Summary of the Invention

[0006] To solve the above problems, the present invention provides a modified PVC cable compound and a preparation method thereof.

[0007] In the first aspect, the present invention provides a modified PVC cable compound, which, in parts by weight, comprises the following components:

[0008] 95 - 105 parts of modified polyvinyl chloride base material, 25 - 40 parts of filler, 35 - 45 parts of plasticizer, 8 - 15 parts of flame retardant, 5 - 12 parts of stabilizer, 0.8 - 1.5 parts of ultraviolet absorber, 0.5 - 2 parts of antioxidant, and 1 - 2 parts of lubricant;

[0009] The modified polyvinyl chloride base material is obtained by swelling polyvinyl chloride with CO2 supercritical fluid and then adding hyperbranched epoxy resin and ionic liquid for kneading; the ionic liquid is an imidazole ionic liquid containing a C8 - C12 long-chain alkyl group.

[0010] Furthermore, by weight, the modified PVC cable material comprises the following components:

[0011] 100 parts of modified polyvinyl chloride base material, 35 parts of filler, 40 parts of plasticizer, 12 parts of flame retardant, 7.5 parts of stabilizer, 1.2 parts of ultraviolet absorber, 1.5 parts of antioxidant, and 1.5 parts of lubricant.

[0012] Furthermore, the preparation method of the modified polyvinyl chloride base material comprises the following steps:

[0013] Place polyvinyl chloride in a closed device, remove air and introduce CO2, then carry out CO2 supercritical fluid swelling treatment at 50 - 60 °C and 20 - 30 MPa for 2 - 5 minutes, relieve pressure to obtain the first polyvinyl chloride;

[0014] Add the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid into a two-roll kneader according to a weight ratio of 100:(15 - 22):(4 - 9), and then carry out kneading at a temperature of 160 - 165 °C for 20 - 30 minutes to obtain the modified polyvinyl chloride base material.

[0015] Furthermore, the weight ratio of the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid is 100:19:7.

[0016] Furthermore, the ionic liquid includes at least one of 1-octyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium bromide, 1-decyl-3-methylimidazolium chloride, 1-dodecyl-3-methylimidazolium chloride, and 1-dodecyl-3-methylimidazolium bromide.

[0017] Furthermore, the filler includes at least one of heavy calcium carbonate powder, talc powder, and mica powder, and the plasticizer includes at least one of tributyl acetylcitrate and dioctyl adipate.

[0018] Further, the flame retardant includes at least one of aluminum hydroxide and antimony trioxide, the stabilizer includes calcium-zinc stabilizer, the antioxidant includes at least one of antioxidant 1010 and antioxidant BHT, the lubricant includes at least one of calcium stearate and polyethylene wax, and the ultraviolet absorber includes at least one of 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone.

[0019] In a second aspect, based on the same inventive concept, the present invention provides a method for preparing the modified PVC cable material according to any one of the first aspect, and the preparation method includes the following steps:

[0020] Perform first heating and stirring mixing on the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant and lubricant to obtain a first mixture;

[0021] Add a filler and a flame retardant to the first mixture and perform second heating and stirring mixing to obtain a second mixture;

[0022] Add the second mixture into a twin-screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable material.

[0023] Further, the working condition parameters of the first heating and stirring mixing include: the temperature is 85-90 °C, the time is 10-20 minutes, and the rotation speed is 100-200 rpm; the working condition parameters of the second heating and stirring mixing include: the temperature is 125-135 °C, the time is 10-20 minutes, and the rotation speed is 800-1000 rpm.

[0024] Further, the working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extrusion is 170 °C - 180 °C, the temperature of the extrusion head is 185 °C - 195 °C, and the screw rotation speed is 100 r / min - 150 r / min.

[0025] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0026] The embodiments of the present invention provide a modified PVC cable material and a preparation method thereof. On the basis of the existing PVC cable material formula, the present invention mainly realizes physical-chemical combined modification of the PVC base material by adopting the CO2 supercritical fluid process and introducing specific hyperbranched epoxy resin and ionic liquid, effectively improving the low-temperature resistance and mechanical properties of the PVC cable material, etc., so as to meet the use requirements for long-term application in extreme cold environments such as below -50 °C, and making up for the deficiencies of the existing PVC cable material. Specifically:

[0027] 1) On the one hand, when the polyvinyl chloride material is in a CO2 supercritical fluid environment, the present invention utilizes the unique physical and chemical properties of the CO2 supercritical fluid, such as high diffusivity and high solubility of liquids, to cause the polyvinyl chloride material to swell, which not only makes the molecular chains of the polyvinyl chloride looser and increases the activity of the molecular chains, thus achieving physical modification, but also provides more reaction and penetration space for the subsequent addition of hyperbranched epoxy resins and ionic liquids, thereby enhancing the modification effect;

[0028] 2) On the other hand, during the mixing process, the hyperbranched epoxy resin and the imidazole ionic liquid containing C8-C12 long-chain alkyl groups can form a dual effect at the chemical and physical levels with the PVC base material after swelling treatment, enhancing the interaction force between the molecular chains of the PVC base material as well as the flexibility and processing performance, so that the material can still maintain good stability and plasticity at low temperatures, which not only improves the molecular structure and cold resistance of the polyvinyl chloride material itself, but also provides a good foundation for the dispersion and synergistic effect of other additives such as plasticizers and fillers, so that they can be more evenly distributed in the material, give full play to their respective roles, and improve the comprehensive performance of the cable material.

[0029] Therefore, the modified polyvinyl chloride material in the present invention is the core of the technical solution. The modified polyvinyl chloride material plays a key role in improving the low temperature resistance and mechanical properties of PVC cable materials, so that the cable materials can adapt to extremely cold environments such as below -50°C. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0032] In a first aspect, the present invention provides a modified PVC cable material, wherein the modified PVC cable material comprises the following components in parts by weight:

[0033] 95-105 parts of modified polyvinyl chloride material, 25-40 parts of filler, 35-45 parts of plasticizer, 8-15 parts of flame retardant, 5-12 parts of stabilizer, 0.8-1.5 parts of ultraviolet absorber, 0.5-2 parts of antioxidant and 1-2 parts of lubricant;

[0034] The modified polyvinyl chloride base material is obtained by swelling polyvinyl chloride with supercritical carbon dioxide fluid and then adding hyperbranched epoxy resin and ionic liquid for kneading; the ionic liquid is an imidazole-based ionic liquid containing C8-C12 long-chain alkyl groups.

[0035] The embodiment of the present invention provides a modified PVC cable material. On the basis of the existing PVC cable material formula, the present invention mainly realizes physical-chemical combined modification of the PVC base material by adopting a supercritical carbon dioxide fluid process and introducing specific hyperbranched epoxy resin and ionic liquid, effectively improving the low-temperature resistance and mechanical properties of the PVC cable material, etc., so as to meet the use requirements for long-term application in extreme cold environments such as below -50°C, and making up for the deficiencies of the existing PVC cable material.

[0036] Polyvinyl chloride (PVC) in the present invention is a high-molecular compound polymerized from vinyl chloride monomer (VCM). In PVC cable materials, polyvinyl chloride is used as the base resin and mixed with various additives such as stabilizers, plasticizers, lubricants, and fillers, and processed through specific processing techniques to make cable materials with different properties. These cable materials are widely used in parts such as the insulation layer and sheath of wires and cables to ensure the safe and stable operation of the cables, such as the PVC cable materials disclosed in prior arts such as CN108070181A - A PVC cable material resistant to high-temperature aging and its preparation method, CN112552621A - Wear-resistant and impact-resistant cable material and its preparation method, CN107857955A - A cold-resistant (-40°C) and high-flame-retardant (OI≥38) PVC cable material and its preparation method. In some specific embodiments, the polyvinyl chloride in the present invention can directly adopt the PVC cable materials disclosed in the above prior arts or directly purchase polyvinyl chloride resins with a polymerization degree of about 1300 such as Hanwha HG-1300 and Qingdao Haijing HS-1300 on the market. Hanwha HG-1300 is selected in the subsequent examples and comparative examples of the present invention.

[0037] The hyperbranched epoxy resin in the present invention is a high-molecular material with a special molecular structure. Its molecular structure mainly includes a hyperbranched core part and an end group part with epoxy functional groups, showing a highly branched form and having a large number of cavities inside, endowing it with unique properties and application advantages. In some specific embodiments, the polyvinyl chloride in the present invention can directly adopt commercially available products such as HyPer E102 and EV-2098. The hyperbranched epoxy resin HyPer E102 of Wuhan Hyperbranched Resin Technology Co., Ltd. is selected in the subsequent examples and comparative examples of the present invention.

[0038] In the present invention, an ionic liquid is a salt composed of organic cations and inorganic anions (or organic anions), which is in a liquid state at room temperature. They have a series of unique physical and chemical properties and thus have a wide range of applications in multiple fields. In the present invention, the long-chain alkyl group in the imidazole-based ionic liquid containing C8-C12 long-chain alkyl groups has a certain flexibility and lubricity, and the modification effect on the polyvinyl chloride base material is significantly better than that of short-chain alkyl imidazole-based ionic liquids such as 1-ethyl-3-methylimidazolium bromide.

[0039] As an implementation manner of an embodiment of the present application, by weight, the modified PVC cable material comprises the following components:

[0040] 100 parts of modified polyvinyl chloride base material, 35 parts of filler, 40 parts of plasticizer, 12 parts of flame retardant, 7.5 parts of stabilizer, 1.2 parts of ultraviolet absorber, 1.5 parts of antioxidant, and 1.5 parts of lubricant.

[0041] The present invention further screens and finds that the modified PVC cable material prepared with the above specific ratio performs excellently in various performance indicators, and the comprehensive performance reaches the best state. This ratio not only gives full play to the synergistic effect between the components but also ensures the reliability, safety, and economy of the cable material in practical applications.

[0042] As an implementation manner of an embodiment of the present application, the preparation method of the modified polyvinyl chloride base material comprises the following steps:

[0043] Place polyvinyl chloride in a closed device, remove air, and introduce CO2, and then carry out CO2 supercritical fluid swelling treatment at 50-60°C and 20-30 MPa for 2-5 minutes, and relieve pressure to obtain the first polyvinyl chloride;

[0044] Add the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid into a two-roll mixer according to a weight ratio of 100:(15-22):(4-9), and then carry out mixing at a temperature of 160-165°C for 20-30 minutes to obtain the modified polyvinyl chloride base material.

[0045] In the present invention, the preparation process of the modified polyvinyl chloride base material can be carried out using existing equipment without additional specific equipment, and the operation is simple. In some specific embodiments, the parameter conditions of the CO2 supercritical fluid swelling treatment are preferably 54°C and 25 MPa; the preferred mixing temperature is 163°C.

[0046] As an implementation manner of an embodiment of the present application, the weight ratio of the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid is 100:19:7.

[0047] When the weight ratio of the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid in the present invention is 100:19:7, the properties of the obtained modified polyvinyl chloride base material are the best.

[0048] As an implementation manner of an embodiment of the present application, the ionic liquid includes at least one of 1-octyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium bromide, 1-decyl-3-methylimidazolium chloride, 1-dodecyl-3-methylimidazolium chloride, and 1-dodecyl-3-methylimidazolium bromide, and preferably 1-decyl-3-methylimidazolium chloride.

[0049] As an implementation manner of an embodiment of the present application, the filler includes at least one of heavy calcium carbonate powder, talc powder, and mica powder, the plasticizer includes at least one of tributyl acetylcitrate and dioctyl adipate, the flame retardant includes at least one of aluminum hydroxide and antimony trioxide, the stabilizer includes a calcium-zinc stabilizer, the antioxidant includes at least one of antioxidant 1010 and antioxidant BHT, the lubricant includes at least one of calcium stearate and polyethylene wax, and the ultraviolet absorber includes at least one of 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone.

[0050] Preferably, in the present invention, the filler is obtained by mixing heavy calcium carbonate powder, talc powder, and mica powder with a weight ratio of 3:1:1, grinding them, and passing through a 1000-mesh sieve; the plasticizer is composed of tributyl acetylcitrate and dioctyl adipate with a weight ratio of 2:1; the flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide with a weight ratio of 1:1, grinding them, and passing through an 800-mesh sieve; the stabilizer can be a calcium-zinc stabilizer such as CZ300M, BP MC9875KA / 1, etc.; the antioxidant is composed of antioxidant 1010 and antioxidant BHT with a weight ratio of 5:1; the lubricant is calcium stearate; and the ultraviolet absorber is 2-hydroxy-4-methoxybenzophenone.

[0051] In a second aspect, based on the same inventive concept, the present invention provides a preparation method for the modified PVC cable material according to any one of the first aspect, and the preparation method includes the following steps:

[0052] Perform first heating and stirring mixing on the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant, and lubricant to obtain a first mixture;

[0053] Add the filler and the flame retardant to the first mixture and perform second heating and stirring mixing to obtain a second mixture;

[0054] Add the second mixture to a twin-screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable material.

[0055] The preparation method of the modified PVC cable material provided by the embodiments of the present invention is simple in operation, does not require additional specific equipment, and is suitable for industrial mass production; at the same time, this preparation method is realized based on the modified PVC cable material described in any item of the first aspect, so it has at least the beneficial effects of the modified PVC cable material described in any item of the first aspect, which will not be elaborated one by one here.

[0056] As an implementation manner of the embodiments of the present application, the working condition parameters of the first heating and stirring mixture include: the temperature is 85-90 °C, the time is 10-20 minutes, and the rotation speed is 100-200 rpm; the working condition parameters of the second heating and stirring mixture include: the temperature is 125-135 °C, the time is 10-20 minutes, and the rotation speed is 800-1000 rpm.

[0057] As an implementation manner of the embodiments of the present application, the working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extrusion is 170 °C - 180 °C, the temperature of the extrusion head is 185 °C - 195 °C, and the screw rotation speed is 100 r / min - 150 r / min.

[0058] It should be noted that for the component raw materials involved in the modified PVC cable material and its preparation method provided by the embodiments of the present invention, if there is no special limitation or specific description, commercially available products can be directly used or self-made by using existing publicly disclosed preparation methods; at the same time, for the steps and parameters involved, if there is no special limitation or specific description, they can be carried out according to the PVC cable material processing technology disclosed in the prior art or directly using existing equipment, which will not be elaborated one by one in this invention document.

[0059] The following further elaborates the present invention in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0060] Example 1

[0061] This example provides a modified PVC cable material. Calculated by weight parts, the modified PVC cable material includes the following components:

[0062] 100 parts of modified polyvinyl chloride base material, 35 parts of filler, 40 parts of plasticizer, 12 parts of flame retardant, 7.5 parts of stabilizer, 1.2 parts of ultraviolet absorber, 1.5 parts of antioxidant, 1.5 parts of lubricant;

[0063] The modified polyvinyl chloride base material is obtained by subjecting polyvinyl chloride resin to CO2 supercritical fluid swelling treatment, and then adding hyperbranched epoxy resin HyPer E102 and 1-decyl-3-methylimidazolium chloride for kneading. The specific process includes the following steps:

[0064] Place the polyvinyl chloride in a closed device, remove the air, and introduce CO2. Then, perform CO2 supercritical fluid swelling treatment at 54 °C and 25 MPa for 3 minutes, and release the pressure to obtain the first polyvinyl chloride. Add the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid to a two-roll kneader according to a weight ratio of 100:19:7, and then perform kneading at 163 °C for 25 minutes to obtain the modified polyvinyl chloride base material;

[0065] The filler is obtained by mixing heavy calcium carbonate powder, talc powder, and mica powder with a weight ratio of 3:1:1, grinding them, and passing through a 1000-mesh sieve;

[0066] The plasticizer is composed of tributyl acetylcitrate and dioctyl adipate with a weight ratio of 2:1;

[0067] The flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide with a weight ratio of 1:1, grinding them, and passing through an 800-mesh sieve;

[0068] The stabilizer is a calcium-zinc stabilizer;

[0069] The ultraviolet absorber is 2-hydroxy-4-methoxybenzophenone;

[0070] The antioxidant is composed of antioxidant 1010 and antioxidant BHT with a weight ratio of 5:1;

[0071] The lubricant is calcium stearate.

[0072] The preparation method of the above-mentioned modified PVC cable material includes the following steps:

[0073] Perform first heating and stirring mixing on the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant, and lubricant to obtain a first mixture;

[0074] Add the filler and the flame retardant to the first mixture for second heating and stirring mixing to obtain a second mixture;

[0075] Add the second mixture to a twin-screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable material;

[0076] Among them, the working condition parameters of the first heating and stirring mixing include: temperature of 88°C, time of 15 minutes, and rotation speed of 150 rpm; the working condition parameters of the second heating and stirring mixing include: temperature of 130°C, time of 15 minutes, and rotation speed of 900 rpm; the working condition parameters of the twin-screw extruder include: body temperature of 175°C for twin-screw extrusion, head temperature of 190°C for extrusion, and screw rotation speed of 120 r / min.

[0077] Example 2

[0078] This example provides a modified PVC cable material. In parts by weight, the modified PVC cable material includes the following components:

[0079] 95 parts of modified polyvinyl chloride base material, 25 parts of filler, 35 parts of plasticizer, 8 parts of flame retardant, 5 parts of stabilizer, 0.8 part of ultraviolet absorber, 0.5 part of antioxidant, and 1 part of lubricant;

[0080] The modified polyvinyl chloride base material is obtained by subjecting polyvinyl chloride resin to CO2 supercritical fluid swelling treatment and then adding hyperbranched epoxy resin HyPer E102 and 1-octyl-3-methylimidazolium chloride for kneading. The specific process includes the following:

[0081] Place polyvinyl chloride in a closed device, remove air and introduce CO2, then carry out CO2 supercritical fluid swelling treatment at 50°C and 20 MPa for 5 minutes, relieve pressure to obtain the first polyvinyl chloride; add the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid to a two-roll kneader in a weight ratio of 100:15:4, and then carry out kneading at 160°C for 30 minutes to obtain the modified polyvinyl chloride base material;

[0082] The filler is obtained by mixing heavy calcium carbonate powder, talc powder, and mica powder in a weight ratio of 3:1:1, grinding them, and passing through a 1000-mesh sieve;

[0083] The plasticizer is composed of tributyl acetylcitrate and dioctyl adipate in a weight ratio of 2:1;

[0084] The flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide in a weight ratio of 1:1, grinding them, and passing through an 800-mesh sieve;

[0085] The stabilizer is a calcium-zinc stabilizer;

[0086] The ultraviolet absorber is 2-hydroxy-4-methoxybenzophenone;

[0087] The antioxidant is composed of antioxidant 1010 and antioxidant BHT in a weight ratio of 5:1;

[0088] The lubricant is calcium stearate.

[0089] The preparation method of the above modified PVC cable material comprises the following steps:

[0090] Carry out first heating, stirring and mixing on the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant and lubricant to obtain a first mixture;

[0091] Add a filler and a flame retardant to the first mixture and carry out second heating, stirring and mixing to obtain a second mixture;

[0092] Add the second mixture into a twin-screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable material;

[0093] Among them, the working condition parameters of the first heating, stirring and mixing include: temperature is 90 °C, time is 10 minutes, and rotation speed is 200 rpm; the working condition parameters of the second heating, stirring and mixing include: temperature is 135 °C, time is 10 minutes, and rotation speed is 1000 rpm; the working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extrusion is 180 °C, the temperature of the extrusion head is 195 °C, and the screw rotation speed is 150 r / min.

[0094] Example 3

[0095] This example provides a modified PVC cable material. Calculated by weight parts, the modified PVC cable material comprises the following components:

[0096] 105 parts of modified polyvinyl chloride base material, 40 parts of filler, 45 parts of plasticizer, 15 parts of flame retardant, 12 parts of stabilizer, 1.5 parts of ultraviolet absorber, 2 parts of antioxidant, 2 parts of lubricant;

[0097] The modified polyvinyl chloride base material is obtained by subjecting polyvinyl chloride resin to CO2 supercritical fluid swelling treatment and then adding hyperbranched epoxy resin HyPer E102 and 1-octyl-3-methylimidazolium chloride for kneading. Specifically, it comprises the following process:

[0098] Place polyvinyl chloride in a closed device, remove air and introduce CO2, and then carry out CO2 supercritical fluid swelling treatment at 60 °C and 30 MPa for 2 minutes, relieve pressure to obtain first polyvinyl chloride; add the first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid into a two-roll kneader according to a weight ratio of 100:22:9, and then carry out kneading at 165 °C for 20 minutes to obtain the modified polyvinyl chloride base material;

[0099] The filler is obtained by mixing heavy calcium carbonate powder, talcum powder and mica powder with a weight ratio of 3:1:1, grinding and passing through a 1000-mesh sieve;

[0100] The plasticizer is composed of tributyl acetylcitrate and dioctyl adipate with a weight ratio of 2:1;

[0101] The flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide with a weight ratio of 1:1, grinding them, and passing through an 800-mesh sieve;

[0102] The stabilizer is a calcium-zinc stabilizer;

[0103] The ultraviolet absorber is 2-hydroxy-4-methoxybenzophenone;

[0104] The antioxidant is composed of antioxidant 1010 and antioxidant BHT with a weight ratio of 5:1;

[0105] The lubricant is calcium stearate.

[0106] The preparation method of the above-mentioned modified PVC cable material includes the following steps:

[0107] First, heat and stir the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant, and lubricant to mix them, obtaining a first mixture;

[0108] Add filler and flame retardant to the first mixture and conduct a second heat and stir mixing to obtain a second mixture;

[0109] Add the second mixture into a twin-screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable material;

[0110] Among them, the working condition parameters of the first heat and stir mixing include: temperature of 85 °C, time of 20 minutes, and rotation speed of 100 rpm; the working condition parameters of the second heat and stir mixing include: temperature of 125 °C, time of 20 minutes, and rotation speed of 800 rpm; the working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extrusion is 170 °C, the temperature of the extrusion head is 185 °C, and the screw rotation speed is 100 r / min.

[0111] Comparative Example 1

[0112] This example provides a modified PVC cable material and its preparation method, and the difference from Example 1 is only that: the modified polyvinyl chloride base material in Example 1 is adjusted to unmodified polyvinyl chloride resin; the remaining steps and parameters are the same.

[0113] Comparative Example 2

[0114] This example provides a modified PVC cable compound and its preparation method. The difference from Example 1 is only that: the preparation process of the modified polyvinyl chloride base material is specifically as follows: Place polyvinyl chloride in a closed device, remove air and introduce CO2, and then perform CO2 supercritical fluid swelling treatment at 50 °C and 20 MPa for 5 minutes, release the pressure to obtain the modified polyvinyl chloride base material (i.e., the kneading step is not carried out); the remaining steps and parameters are the same.

[0115] Comparative Example 3

[0116] This example provides a modified PVC cable compound and its preparation method. The difference from Example 1 is only that: the preparation process of the modified polyvinyl chloride base material is specifically as follows: Add polyvinyl chloride, hyperbranched epoxy resin and ionic liquid into a two-roll kneader according to a weight ratio of 100:15:4, and then perform kneading at 160 °C for 30 minutes to obtain the modified polyvinyl chloride base material (i.e., the CO2 supercritical fluid swelling treatment step is not carried out); the remaining steps and parameters are the same.

[0117] Test Example 1

[0118] This example aims to investigate the low-temperature resistance of the modified PVC cable compounds obtained in the above Examples 1 to 3 and Comparative Examples 1 to 3; among them, the low-temperature impact strength (KJ / m 2 ) was tested with reference to the standard GB / T2843-2008, and the embrittlement temperature (°C) was tested with reference to the standard GB / T5470-2008. The test results are shown in Table 1.

[0119] Table 1

[0120]

[0121] It can be seen from Table 1 that: compared with Comparative Examples 1 to 3, in Examples 1 to 3 of the present invention, the modified polyvinyl chloride base material obtained by subjecting polyvinyl chloride to CO2 supercritical fluid swelling treatment and then adding hyperbranched epoxy resin and ionic liquid for kneading significantly improves the low-temperature resistance of the obtained modified PVC cable compound. At the same time, the present invention uses the CO2 supercritical fluid process and introduces specific hyperbranched epoxy resin and ionic liquid to achieve physical-chemical combined modification of the PVC base material, and the two show a significant synergistic effect.

[0122] Test Example 2

[0123] On the basis of Test Example 1, the present invention further tests the mechanical properties of the modified PVC cable compounds obtained in Examples 1 to 3. The test results are shown in Table 2.

[0124] Table 2

[0125] Test sample Tensile strength (MPa) Example 1 40.1 Example 2 32.6 Example 3 35.9

[0126] As can be seen from Table 2, the tensile strength of the modified PVC cable materials provided in Embodiments 1 to 3 of the present invention is maintained above 30 MPa, and can reach up to 40.1 MPa at most, indicating excellent mechanical properties.

[0127] In summary, the embodiments of the present invention provide a modified PVC cable material and a preparation method thereof. Based on the existing PVC cable material formula, the present invention mainly realizes physical-chemical combined modification of the PVC base material by adopting the CO2 supercritical fluid process and introducing specific hyperbranched epoxy resins and ionic liquids, effectively improving the low-temperature resistance and mechanical properties of the PVC cable material, etc., so as to meet the use requirements for long-term application in extreme cold environments such as below -50 °C, and making up for the deficiencies of the existing PVC cable materials.

[0128] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0129] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A modified PVC cable compound, characterized in that, By weight parts, the modified PVC cable compound comprises the following components: 95 - 105 parts of modified polyvinyl chloride base material, 25 - 40 parts of filler, 35 - 45 parts of plasticizer, 8 - 15 parts of flame retardant, 5 - 12 parts of stabilizer, 0.8 - 1.5 parts of ultraviolet absorber, 0.5 - 2 parts of antioxidant and 1 - 2 parts of lubricant; The modified polyvinyl chloride base material is obtained by subjecting polyvinyl chloride to CO2 supercritical fluid swelling treatment, and then adding hyperbranched epoxy resin and ionic liquid for kneading; the ionic liquid is an imidazole - type ionic liquid containing C8 - C12 long - chain alkyl groups.

2. The modified PVC cable compound according to claim 1, wherein By weight parts, the modified PVC cable compound comprises the following components: 100 parts of modified polyvinyl chloride base material, 35 parts of filler, 40 parts of plasticizer, 12 parts of flame retardant, 7.5 parts of stabilizer, 1.2 parts of ultraviolet absorber, 1.5 parts of antioxidant, 1.5 parts of lubricant.

3. The modified PVC cable compound according to claim 1, characterized in that, The preparation method of the modified polyvinyl chloride base material comprises the following steps: Place polyvinyl chloride in a closed device, evacuate the air and introduce CO2, then carry out CO2 supercritical fluid swelling treatment at 50 - 60 °C and 20 - 30 MPa for 2 - 5 minutes, relieve the pressure to obtain the first polyvinyl chloride; Add the first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid into a two - roll kneader according to a weight ratio of 100:(15 - 22):(4 - 9), and then carry out kneading at a temperature of 160 - 165 °C for 20 - 30 minutes to obtain the modified polyvinyl chloride base material.

4. The modified PVC cable compound according to claim 3, characterized in that, The weight ratio of the first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid is 100:19:

7.

5. The modified PVC cable compound according to any one of claims 1 to 4, characterized in that The ionic liquid includes at least one of 1 - octyl - 3 - methylimidazolium chloride, 1 - octyl - 3 - methylimidazolium bromide, 1 - decyl - 3 - methylimidazolium chloride, 1 - dodecyl - 3 - methylimidazolium chloride and 1 - dodecyl - 3 - methylimidazolium bromide.

6. The modified PVC cable compound according to claim 5, wherein The filler includes at least one of heavy calcium carbonate powder, talc powder and mica powder, and the plasticizer includes at least one of tributyl acetylcitrate and dioctyl adipate.

7. The modified PVC cable compound according to claim 5, wherein The flame retardant includes at least one of aluminum hydroxide and antimony trioxide, the stabilizer includes calcium - zinc stabilizer, the antioxidant includes at least one of antioxidant 1010 and antioxidant BHT, the lubricant includes at least one of calcium stearate and polyethylene wax, and the ultraviolet absorber includes at least one of 2 - hydroxy - 4 - methoxybenzophenone and 2 - hydroxy - 4 - n - octyloxybenzophenone.

8. A method for preparing the modified PVC cable material according to any one of claims 1 to 7, characterized in that, The preparation method comprises the following steps: Carry out first heating and stirring mixing on the modified polyvinyl chloride base material, plasticizer, stabilizer, ultraviolet absorber, antioxidant and lubricant to obtain a first mixture; Add the filler and the flame retardant to the first mixture for second heating and stirring mixing to obtain a second mixture; Add the second mixture into a twin - screw extruder for melt extrusion, and then cool and pelletize to obtain the modified PVC cable compound.

9. The preparation method of the modified PVC cable compound according to claim 8, characterized in that, The working condition parameters of the first heating, stirring and mixing include: temperature is 85-90 °C, time is 10-20 minutes, and rotation speed is 100-200 rpm; the working condition parameters of the second heating, stirring and mixing include: temperature is 125-135 °C, time is 10-20 minutes, and rotation speed is 800-1000 rpm.

10. The preparation method of the modified PVC cable compound according to claim 8, characterized in that, The working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extrusion is 170 °C - 180 °C, the temperature of the extrusion head is 185 °C - 195 °C, and the screw rotation speed is 100 r / min - 150 r / min.

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