Modified PVC cable material and preparation method thereof

Abstract

The application 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 in proportion by weight: modified polyvinyl chloride base material 95-105 parts, fillers 25-40 parts, plasticizers 35-45 parts, flame retardants 8-15 parts, stabilizers 5-12 parts, ultraviolet absorbers 0.8-1.5 parts, antioxidants 0.5-2 parts and lubricants 1-2 parts.Based on the existing PVC cable material formula, the PVC base material is physically and chemically modified by adopting a CO2 supercritical fluid process and introducing specific hyperbranched epoxy resin and ionic liquid, so that the low-temperature resistance and mechanical properties of the PVC cable material are effectively improved, the use requirements in an extremely cold environment below-50 DEG C for a long time are met, and the defects of the existing PVC cable material are made up.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyvinyl chloride cable materials, and particularly relates to a modified PVC cable material and a preparation method thereof. BACKGROUND

[0002] As the second largest general-purpose resin in the world after polyethylene, polyvinyl chloride (PVC) has been widely used in the field of cables 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 of cable materials are becoming increasingly high, especially in extreme environmental conditions, such as extremely cold regions, which demand is particularly prominent.

[0003] Currently, traditional PVC cable materials have inherent limitations in terms of low-temperature resistance and mechanical properties, making it difficult to meet the use requirements in these special environments. The reason is that ordinary PVC materials have numerous active centers in their molecular chains, which makes their cold resistance and tensile properties relatively poor. In low-temperature environments, the movement ability of PVC molecular chains is severely restricted, and the material becomes brittle and hard, which is prone to breakage under external force impact. In addition, PVC molecules are also prone to aging over time, further leading to the degradation of cable material performance.

[0004] It is particularly noteworthy that in regions with large diurnal temperature differences such as northern and Russian, northern Europe, and other regions, the daytime temperature can be as high as -10℃ or above, while at night, the temperature can drop to -40℃ or even lower than -60℃. In such extreme low-temperature environments, if the low-temperature impact strength and embrittlement temperature of the cable material do not meet the requirements, the cable is prone to breakage during laying due to the influence of low temperature, thereby seriously 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 material with excellent low-temperature resistance and mechanical properties. This not only meets the use requirements in extreme environments, but also effectively improves the reliability and durability of the cable, providing strong support for the stable development of modern power systems and communication networks. SUMMARY

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

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

[0008] 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;

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

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

[0011] 100 parts of modified polyvinyl chloride 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 material comprises the following steps:

[0013] The polyvinyl chloride is placed in a sealed device, air is removed, CO2 is introduced, and then a CO2 supercritical fluid swelling treatment is performed at 50-60° C. and 20-30 MPa for 2-5 minutes, and the pressure is released to obtain a first polyvinyl chloride;

[0014] The first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid are added into a double-roll mixer in a weight ratio of 100:(15-22):(4-9), and then mixed at a temperature of 160-165° C. for 20-30 minutes to obtain the modified polyvinyl chloride 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 acetyl tri-n-butyl citrate and dioctyl adipate.

[0018] Further, the flame retardant includes at least one of aluminum hydroxide and diantimony 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.

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

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

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

[0022] The second mixture is added to a double-screw extruder to perform melt extrusion, and then cooling and granulation to obtain the modified PVC cable material.

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

[0024] Further, the working condition parameters of the double-screw extruder include a body temperature of 170 DEG C-180 DEG C, an extruder head temperature of 185 DEG C-195 DEG C and a screw rotation speed of 100 r / min-150 r / min.

[0025] Compared with the prior art, the above technical solution provided by the embodiments of the application has at least the following advantages:

[0026] The embodiments of the application provide a modified PVC cable material and a preparation method thereof, and on the basis of an existing PVC cable material formula, the PVC base material is physically and chemically modified by using a CO2 supercritical fluid process and introducing specific hyperbranched epoxy resin and ionic liquid, so that the low-temperature resistance and mechanical properties of the PVC cable material are effectively improved, the use requirements in an extremely cold environment below-50 DEG C and the like are met, and the deficiencies of the existing PVC cable material are made up.

[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. This not only makes the molecular chains of the polyvinyl chloride looser and increases the mobility of the molecular chains, thus achieving physical modification, but also provides more reaction and penetration space for the subsequent addition of hyperbranched epoxy resin and ionic liquid, 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. It 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 PVC material in the present invention is the core of this technical solution. The modified PVC material plays a key role in improving the low-temperature resistance and mechanical properties of PVC cable materials, enabling the cable materials to adapt to extremely cold environments such as below -50°C. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts 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, which 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 material is obtained by subjecting polyvinyl chloride to a CO2 supercritical fluid swelling treatment, and then adding a hyperbranched epoxy resin and an ionic liquid for mixing; the ionic liquid is an imidazole ionic liquid containing a C8-C12 long-chain alkyl group.

[0035] An embodiment of the present invention provides a modified PVC cable material. Based on the existing PVC cable material formula, the present invention mainly realizes physical-chemical combined modification of the PVC base material by adopting a CO2 supercritical fluid process and introducing a specific hyperbranched epoxy resin and an ionic liquid, thereby effectively improving the low-temperature resistance and mechanical properties of the PVC cable material, thereby meeting the requirements for long-term application in extremely cold environments such as below -50°C, and making up for the shortcomings of existing PVC cable materials.

[0036] In the present invention, polyvinyl chloride (PVC) is a polymer compound formed by the polymerization of vinyl chloride monomer (VCM). In PVC cable materials, PVC serves as the base resin and is mixed with various additives, such as stabilizers, plasticizers, lubricants, and fillers. Through specific processing techniques, cable materials with different properties are produced. These cable materials are widely used in the insulation layer and sheath of wires and cables to ensure the safe and stable operation of the cables. Examples include CN108070181A - A High-Temperature-Aging-Resistant PVC Cable Material and Its Preparation Method, CN112552621A - A Wear-Resistant and Impact-Resistant Cable Material and Its Preparation Method, and CN107857955A - A Cold-Resistant (-40°C), Highly 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 material disclosed in the above-mentioned prior art or directly purchase commercially available polyvinyl chloride resins with a degree of polymerization of about 1300, such as Hanwha HG-1300 and Qingdao Haijing HS-1300. Hanwha HG-1300 is selected in the subsequent embodiments and comparative examples of the present invention.

[0037] The hyperbranched epoxy resin in the present invention is a polymer material with a unique molecular structure. Its molecular structure mainly includes a hyperbranched core portion and an end group portion having epoxy functional groups, presenting a highly branched morphology and containing a large number of cavities, which give it unique performance and application advantages. In some specific embodiments, the polyvinyl chloride in the present invention can directly use commercially available products such as HyPer E102 and EV-2098. The hyperbranched epoxy resin HyPer E102 produced by Wuhan Hyperbranched Resin Technology Co., Ltd. is used in the subsequent embodiments and comparative examples of the present invention.

[0038] In the present invention, ionic liquids are salts composed of organic cations and inorganic anions (or organic anions) that are liquid at room temperature. They possess a range of unique physical and chemical properties, and therefore have broad applications in various fields. The long-chain alkyl imidazole ionic liquids selected in the present invention contain C8-C12 long-chain alkyl groups, which have certain flexibility and lubricity. Their modification effect on polyvinyl chloride (PVC) materials is significantly superior to that of short-chain alkyl imidazole ionic liquids, such as 1-ethyl-3-methylimidazolium bromide.

[0039] As an implementation method of the present application, the modified PVC cable material includes the following components in parts by weight:

[0040] 100 parts of modified polyvinyl chloride 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] Further screening by the present inventors revealed that the modified PVC cable material prepared using this specific ratio exhibited excellent performance across all performance indicators, achieving optimal overall performance. This ratio not only fully leverages the synergistic effects of the various components but also ensures the reliability, safety, and cost-effectiveness of the cable material in practical applications.

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

[0043] The polyvinyl chloride is placed in a sealed device, air is removed, CO2 is introduced, and then a CO2 supercritical fluid swelling treatment is performed at 50-60° C. and 20-30 MPa for 2-5 minutes, and the pressure is released to obtain a first polyvinyl chloride;

[0044] The first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid are added into a double-roll mixer in a weight ratio of 100:(15-22):(4-9), and then mixed at a temperature of 160-165° C. for 20-30 minutes to obtain the modified polyvinyl chloride material.

[0045] The modified PVC material of the present invention can be prepared using existing equipment, without the need for additional specialized equipment, and is simple to operate. In some specific embodiments, the CO2 supercritical fluid swelling treatment is preferably performed at 54°C and 25 MPa; and the mixing temperature is preferably 163°C.

[0046] As an implementation method of an example 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] The weight ratio of the first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid is 100:19:7, and the performance of the obtained modified polyvinyl chloride base is optimal.

[0048] As an embodiment of the present application, the ionic liquid comprises at least one of 1-octyl-3-methyl imidazole chloride, 1-octyl-3-methyl imidazole bromide, 1-decyl-3-methyl imidazole chloride, 1-dodecyl-3-methyl imidazole chloride and 1-dodecyl-3-methyl imidazole bromide, and preferably 1-decyl-3-methyl imidazole chloride.

[0049] As an embodiment of the present application, the filler comprises at least one of heavy calcium carbonate powder, talc powder and mica powder, the plasticizer comprises at least one of acetyl tri-n-butyl citrate and dioctyl adipate, the flame retardant comprises at least one of aluminum hydroxide and antimony trioxide, the stabilizer comprises calcium-zinc stabilizer, the antioxidant comprises at least one of antioxidant 1010 and antioxidant BHT, the lubricant comprises at least one of calcium stearate and polyethylene wax, and the ultraviolet absorber comprises at least one of 2-hydroxy-4-methoxy benzophenone and 2-hydroxy-4-n-octyloxy benzophenone.

[0050] Preferably, the filler in the present application is obtained by mixing and grinding heavy calcium carbonate powder, talc powder and mica powder in a weight ratio of 3:1:1 and then passing through a 1000-mesh sieve, the plasticizer is composed of acetyl tri-n-butyl citrate and dioctyl adipate in a weight ratio of 2:1, the flame retardant is obtained by mixing and grinding aluminum hydroxide and antimony trioxide in a weight ratio of 1:1 and then passing through an 800-mesh sieve, the stabilizer can be selected from calcium-zinc stabilizers such as CZ300M and BP MC9875KA / 1, the antioxidant is composed of antioxidant 1010 and antioxidant BHT in a weight ratio of 5:1, the lubricant is calcium stearate, and the ultraviolet absorber is 2-hydroxy-4-methoxy benzophenone.

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

[0052] The modified polyvinyl chloride base, the plasticizer, the stabilizer, the ultraviolet absorber, the antioxidant and the lubricant are mixed by first heating and stirring to obtain a first mixture;

[0053] The filler and the flame retardant are added to the first mixture and mixed by second heating and stirring to obtain a second mixture;

[0054] The second mixture is added to a twin-screw extruder for melt extrusion, and then cooled and granulated to obtain the modified PVC cable material.

[0055] The preparation method of the modified PVC cable material provided in the embodiment of the present invention is simple to operate, does not require additional specific equipment, and is suitable for industrial mass production; at the same time, the preparation method is implemented based on the modified PVC cable material described in any one of the first aspects, and therefore has at least the beneficial effects of the modified PVC cable material described in any one of the first aspects, which will not be described in detail here.

[0056] As an implementation method of an embodiment of the present application, the working condition parameters of the first heating, stirring and mixing include: temperature of 85~90℃, time of 10~20 minutes, and speed of 100~200rpm; the working condition parameters of the second heating, stirring and mixing include: temperature of 125~135℃, time of 10~20 minutes, and speed of 800~1000rpm.

[0057] As an implementation method of an embodiment of the present application, the working condition parameters of the twin-screw extruder include: the body temperature of the twin-screw extruder is 170℃~180℃, the extruder head temperature is 185℃~195℃, and the screw speed is 100r / min~150r / min.

[0058] It should be noted that the component raw materials involved in the modified PVC cable material and the preparation method thereof provided in the embodiments of the present invention, unless otherwise specified or specifically explained, can be directly commercially available products or homemade using existing disclosed preparation methods; at the same time, the steps and parameters involved, unless otherwise specified or specifically explained, can be carried out in accordance with the PVC cable material processing technology disclosed in the prior art or directly using existing equipment, and the present invention document will not elaborate on them one by one.

[0059] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0060] Example 1

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

[0062] 100 parts of modified polyvinyl chloride 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;

[0063] The modified polyvinyl chloride material is obtained by subjecting polyvinyl chloride resin to a CO2 supercritical fluid swelling treatment, and then adding hyperbranched epoxy resin HyPer E102 and 1-decyl-3-methylimidazolium chloride and mixing them, which specifically includes the following process:

[0064] The polyvinyl chloride is placed in a sealed device, and air is removed and CO2 is introduced, followed by a CO2 supercritical fluid swelling treatment at 54°C and 25MPa for 3 minutes, and the pressure is released to obtain a first polyvinyl chloride; the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid are added to a double-roll mixer in a weight ratio of 100:19:7, and then mixed at 163°C for 25 minutes to obtain the modified polyvinyl chloride material;

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

[0066] The plasticizer is composed of tri-n-butyl acetyl citrate and dioctyl adipate in a weight ratio of 2:1;

[0067] The flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide in a weight ratio of 1:1, grinding the mixture and passing it 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 in a weight ratio of 5:1;

[0071] The lubricant is calcium stearate.

[0072] The preparation method of the modified PVC cable material comprises the following steps:

[0073] The modified polyvinyl chloride material, the plasticizer, the stabilizer, the ultraviolet absorber, the antioxidant and the lubricant are first heated and stirred to obtain a first mixture;

[0074] Adding filler and flame retardant to the first mixture and performing a second heating, stirring and mixing to obtain a second mixture;

[0075] adding the second mixed material into a twin-screw extruder for melt extrusion, and then cooling and granulating to obtain the modified PVC cable material;

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

[0077] Example 2

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

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

[0080] The modified polyvinyl chloride material is obtained by subjecting polyvinyl chloride resin to a CO2 supercritical fluid swelling treatment, and then adding hyperbranched epoxy resin HyPer E102 and 1-octyl-3-methylimidazolium chloride and mixing them, which specifically includes the following process:

[0081] The polyvinyl chloride is placed in a sealed device, and air is removed and CO2 is introduced, followed by a CO2 supercritical fluid swelling treatment at 50°C and 20MPa for 5 minutes, and the pressure is released to obtain a first polyvinyl chloride; the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid are added to a double-roll mixer in a weight ratio of 100:15:4, and then mixed at 160°C for 30 minutes to obtain the modified polyvinyl chloride material;

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

[0083] The plasticizer is composed of tri-n-butyl acetyl citrate 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 the mixture and passing it 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 modified PVC cable material comprises the following steps:

[0090] The modified polyvinyl chloride material, the plasticizer, the stabilizer, the ultraviolet absorber, the antioxidant and the lubricant are first heated and stirred to obtain a first mixture;

[0091] Adding filler and flame retardant to the first mixture and performing a second heating, stirring and mixing to obtain a second mixture;

[0092] adding the second mixed material into a twin-screw extruder for melt extrusion, and then cooling and granulating to obtain the modified PVC cable material;

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

[0094] Example 3

[0095] This example provides a modified PVC cable material, which includes the following components in parts by weight:

[0096] 105 parts of modified polyvinyl chloride 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, and 2 parts of lubricant;

[0097] The modified polyvinyl chloride material is obtained by subjecting polyvinyl chloride resin to a CO2 supercritical fluid swelling treatment, and then adding hyperbranched epoxy resin HyPer E102 and 1-octyl-3-methylimidazolium chloride and mixing them, which specifically includes the following process:

[0098] The polyvinyl chloride is placed in a sealed device, air is removed, and CO2 is introduced, followed by a CO2 supercritical fluid swelling treatment at 60°C and 30 MPa for 2 minutes, and the pressure is released to obtain a first polyvinyl chloride; the first polyvinyl chloride, the hyperbranched epoxy resin, and the ionic liquid are added to a double-roll mixer in a weight ratio of 100:22:9, and then mixed at 165°C for 20 minutes to obtain the modified polyvinyl chloride material;

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

[0100] The plasticizer is composed of tri-n-butyl acetyl citrate and dioctyl adipate in a weight ratio of 2:1;

[0101] The flame retardant is obtained by mixing aluminum hydroxide and antimony trioxide in a weight ratio of 1:1, grinding the mixture and passing it 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 in a weight ratio of 5:1;

[0105] The lubricant is calcium stearate.

[0106] The preparation method of the modified PVC cable material comprises the following steps:

[0107] The modified polyvinyl chloride material, the plasticizer, the stabilizer, the ultraviolet absorber, the antioxidant and the lubricant are first heated and stirred to obtain a first mixture;

[0108] Adding filler and flame retardant to the first mixture and performing a second heating, stirring and mixing to obtain a second mixture;

[0109] adding the second mixed material into a twin-screw extruder for melt extrusion, and then cooling and granulating to obtain the modified PVC cable material;

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

[0111] Comparative Example 1

[0112] This example provides a modified PVC cable material and a preparation method thereof. The only difference from Example 1 is that the modified polyvinyl chloride 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 material and a preparation method thereof. The only difference from Example 1 is that the preparation process of the modified polyvinyl chloride material is as follows: polyvinyl chloride is placed in a closed device, the air is removed, and CO2 is introduced, followed by a CO2 supercritical fluid swelling treatment at 50°C and 20 MPa for 5 minutes, and the pressure is released to obtain the modified polyvinyl chloride material (i.e., no mixing step is performed); the remaining steps and parameters are the same.

[0115] Comparative Example 3

[0116] This example provides a modified PVC cable material and a preparation method thereof. The only difference from Example 1 is that the preparation process of the modified polyvinyl chloride material is as follows: polyvinyl chloride, hyperbranched epoxy resin and ionic liquid are added to a two-roll mixer in a weight ratio of 100:15:4, and then mixed at 160°C for 30 minutes to obtain the modified polyvinyl chloride material (i.e., the CO2 supercritical fluid swelling treatment step is not performed); 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 materials obtained in Examples 1 to 3 and Comparative Examples 1 to 3; among them, the low temperature impact strength (KJ / m 2 ) was tested in accordance with the standard GB / T2843-2008, and the brittle temperature (°C) was tested in accordance with 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, Examples 1 to 3 of the present invention adopt a modified polyvinyl chloride material obtained by subjecting polyvinyl chloride to a CO2 supercritical fluid swelling treatment and then adding a hyperbranched epoxy resin and an ionic liquid for mixing, which significantly improves the low-temperature resistance of the obtained modified PVC cable material. At the same time, the present invention adopts a CO2 supercritical fluid process and introduces a specific hyperbranched epoxy resin and an ionic liquid to achieve a 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 tested the mechanical properties of the modified PVC cable materials obtained in Examples 1 to 3. The test results are shown in Table 2.

[0124] Table 2

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

[0126] From table 2, the tensile strength of the modified PVC cable material provided by the embodiments 1-3 of the present application is maintained at 30 MPa or above, and can be up to 40.1 MPa, indicating that the mechanical properties thereof are excellent.

[0127] In summary, the embodiments of the present application provide a modified PVC cable material and a preparation method thereof, on the basis of the existing PVC cable material formula, the present application mainly realizes physical-chemical combined modification of the PVC base material by using CO2 supercritical fluid process and introducing specific hyperbranched epoxy resin and ionic liquid, effectively improves the low temperature resistance and mechanical properties of the PVC cable material, so as to meet the use requirements in the extremely cold environment below-50℃ and the like for long-term application, and makes up for the deficiencies of the existing PVC cable material.

[0128] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is merely for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the 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, and single numbers within the described range, such as 1, 2, 3, 4, 5 and 6, which is applicable regardless of the range. In addition, whenever a numerical range is indicated in this text, it refers to any cited number (fraction or integer) within the indicated range.

[0129] The above description is only a specific embodiment of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent 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 application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A modified PVC cable material, characterized in that: The modified PVC cable material comprises the following components in parts by weight: 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; The modified polyvinyl chloride material is obtained by subjecting polyvinyl chloride to a CO2 supercritical fluid swelling treatment, and then adding a hyperbranched epoxy resin and an ionic liquid for mixing; the ionic liquid is an imidazole ionic liquid containing a C8-C12 long-chain alkyl group.

2. The modified PVC cable material according to claim 1, characterized in that: The modified PVC cable material comprises the following components in parts by weight: 100 parts of modified polyvinyl chloride 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.

3. The modified PVC cable material according to claim 1, characterized in that: The preparation method of the modified polyvinyl chloride material comprises the following steps: The polyvinyl chloride is placed in a sealed device, air is removed, CO2 is introduced, and then a CO2 supercritical fluid swelling treatment is performed at 50-60° C. and 20-30 MPa for 2-5 minutes, and the pressure is released to obtain a first polyvinyl chloride; The first polyvinyl chloride, the hyperbranched epoxy resin and the ionic liquid are added into a double-roll mixer in a weight ratio of 100:(15-22):(4-9), and then mixed at a temperature of 160-165° C. for 20-30 minutes to obtain the modified polyvinyl chloride material.

4. The modified PVC cable material 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 material 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 material according to claim 5, characterized in that: The filler includes at least one of heavy calcium carbonate powder, talc powder and mica powder, and the plasticizer includes at least one of acetyl tri-n-butyl citrate and dioctyl adipate.

7. The modified PVC cable material according to claim 5, characterized in that: 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.

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: The modified polyvinyl chloride material, the plasticizer, the stabilizer, the ultraviolet absorber, the antioxidant and the lubricant are first heated and stirred to obtain a first mixture; Adding filler and flame retardant to the first mixture and performing a second heating, stirring and mixing to obtain a second mixture; The second mixed material is added into a twin-screw extruder for melt extrusion, and then cooled and granulated to obtain the modified PVC cable material.

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

10. The method for preparing the modified PVC cable material according to claim 8, wherein: The working condition parameters of the twin-screw extruder include: a body temperature of the twin-screw extruder of 170° C. to 180° C., an extruder head temperature of 185° C. to 195° C., and a screw speed of 100 r / min to 150 r / min.

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