Uvioresistant insulating material, process for its preparation and use in cables for electrical equipment

Abstract

The application belongs to the technical field of insulating materials, and particularly relates to a kind of ultraviolet resistant insulating materials, a preparation method thereof and application in cables for electrical equipment. The ultraviolet resistant insulating material comprises the following components by mass fraction: polyvinyl chloride resin 100 parts, modified polybutadiene 5-10 parts, plasticizer 10-20 parts, filler 10-20 parts, composite ultraviolet resistant composition 3-6 parts, antioxidant 0.2-0.8 parts, and lubricant 1-3 parts. The polyvinyl chloride resin has an average polymerization degree of 900-1100, a residual vinyl chloride monomer content of less than or equal to 5 ppm, an impurity particle number of less than or equal to 20 per 100 g, and a fish eye number of less than or equal to 20 per 400 cm 2 The ultraviolet resistant insulating material has excellent ultraviolet resistance.

Description

Technical Field

[0001] This invention belongs to the field of insulating materials technology, specifically relating to an ultraviolet-resistant insulating material, its preparation method, and its application in cables for electrical equipment. Background Technology

[0002] Polyvinyl chloride (PVC) is a thermoplastic polymer with good plasticity and flexibility. It also possesses excellent electrical insulation, corrosion resistance, and non-flammability, making it widely used in cable insulation and protection materials. However, PVC's chemical bonds are easily broken under ultraviolet light, triggering free radical chain reactions that affect its mechanical properties. Furthermore, PVC suffers from poor heat and cold resistance. Therefore, various processing aids are needed to modify it and improve its performance.

[0003] Chinese Patent CN 116987354 A discloses a cold-resistant, rodent-proof, and UV-resistant polymer material for cables, comprising the following raw materials in parts by weight: 50-60 parts of modified PVC material, 2-3 parts of antioxidant, 5-8 parts of UV stabilizer, 3-5 parts of heat stabilizer, 4-6 parts of lubricant, 4-7 parts of rodent-proof agent, and 2-3 parts of flame retardant. The formation process involves mixing all raw materials evenly and then plasticizing them in an open-type mixer to obtain the cold-resistant, rodent-proof, and UV-resistant polymer material for cables. The modified PVC material is formed by combining the reaction product of sebacic acid and n-butanol with polyvinyl chloride, and the UV stabilizer is formed by combining UV-P, 2-hydroxy-4-acrylate benzophenone, and acryloyl chloride. This technical solution significantly enhances the cold-resistant, rodent-proof, and UV-resistant properties of the polymer material for cables by adding the modified PVC material, UV stabilizer, and rodent-proof agent.

[0004] Chinese patent application CN 118588366 A discloses a PVC cable and its preparation method. The PVC cable includes a cable core, an insulation layer, and a sheath layer from the inside out. The sheath layer is formed by extruding a PVC sheath material, which is made of PVC as the main raw material, blended with flame retardant additives, functional fillers, and other additives, onto the outside of the insulation layer. By adding flame retardant additives and functional fillers, and by utilizing the synergistic effect of flame retardant additives and functional fillers, the prepared PVC can have good flame retardant effect, UV aging resistance and heat resistance, and has higher safety and longer service life.

[0005] However, the above-mentioned technical solutions all have poor UV resistance and low tensile strength retention. Therefore, it is of great significance to provide an insulating material with excellent UV resistance. Summary of the Invention

[0006] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, the object of the present invention is to provide an ultraviolet-resistant insulating material with excellent UV resistance.

[0007] A second aspect of the present invention provides a method for preparing an ultraviolet-resistant insulating material.

[0008] A third aspect of the present invention provides the application of an ultraviolet-resistant insulating material in cables for electrical equipment.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] The first aspect of the present invention provides an ultraviolet-resistant insulating material, comprising, by weight, the following components: 100 parts of polyvinyl chloride resin, 5-10 parts of modified polybutadiene, 10-20 parts of plasticizer, 10-20 parts of filler, 3-6 parts of composite ultraviolet-resistant composition, 0.2-0.8 parts of antioxidant, and 1-3 parts of lubricant;

[0011] The polyvinyl chloride resin has an average degree of polymerization of 900-1100, a residual vinyl chloride monomer content of ≤5ppm, an impurity particle count of ≤20 particles / 100g, and a fisheye count (4min) of ≤20 particles / 400cm. 2 .

[0012] More preferably, the polyvinyl chloride resin has an average degree of polymerization of 1030±50, a residual vinyl chloride monomer content of 1ppm, an impurity particle count of ≤10 particles / 100g, and a fisheye count (4min) of ≤10 particles / 400cm. 2 .

[0013] To improve the UV resistance of polyvinyl chloride (PVC) insulation materials, existing technologies typically add UV absorbers. However, under prolonged UV irradiation, the migration of these absorbers leads to a decrease in the mechanical properties of the PVC insulation material. The inventors investigated commercially available PVC resins, noting that the physical properties of PVC produced by different manufacturers vary. During their investigation, the inventors discovered that when the average degree of polymerization of the PVC resin is controlled at 900-1100, the residual vinyl chloride monomer content is ≤5 ppm, the number of impurity particles is ≤20 per 100g, and the number of fish eyes (4min) is ≤20 per 400cm, the optimal resistance is achieved. 2Not only can insulating materials with good mechanical properties be obtained, but when combined with the composite UV-resistant composition of the present invention, the resulting insulating material can simultaneously maintain a tensile strength and elongation at break of over 90% after 2500 hours of UV irradiation. The composite UV-resistant composition of the present invention uses benzotriazole UV absorbers, rutile nano-titanium dioxide, and hindered amine light stabilizers as UV-resistant components, and adds fluoropolymer processing aids. It was found that the addition of fluoropolymer processing aids significantly improved the UV resistance of the insulating material. This may be because the fluoropolymer processing aids migrate to the surface of polyvinyl chloride resin during the preparation of the insulating material due to their low surface energy. The low surface energy polymer "coating" structure formed by the fluoropolymer processing aids can reduce the risk of benzotriazole UV absorbers, rutile nano-titanium dioxide, and hindered amine light stabilizers migrating to the outside of the insulating material under long-term UV irradiation.

[0014] In addition, the inventors have discovered that when the particle size of rutile nano-titanium dioxide is 50-60 nm, its synergistic effect with benzotriazole ultraviolet absorbers and hindered amine light stabilizers can be fully utilized.

[0015] In a preferred embodiment of the present invention, the UV-resistant composition comprises a benzotriazole UV absorber, rutile nano-titanium dioxide, a hindered amine light stabilizer, and a fluoropolymer processing aid in a mass ratio of 1-3:5-8:1-3:10-20.

[0016] Preferably, the UV-resistant composition comprises a benzotriazole UV absorber, rutile nano-titanium dioxide, a hindered amine light stabilizer, and a fluoropolymer processing aid in a mass ratio of 2:6:2:15.

[0017] In a preferred embodiment of the present invention, the particle size of the rutile nano-titanium dioxide is 10-70 nm.

[0018] Preferably, the rutile nano-titanium dioxide has a particle size of 50-60 nm.

[0019] In a preferred embodiment of the present invention, the modified polybutadiene comprises maleic anhydride-modified polybutadiene and epoxidized hydroxyl-modified polybutadiene in a mass ratio of 2-3:1.

[0020] More preferably, the modified polybutadiene is composed of maleic anhydride-modified polybutadiene and epoxidized hydroxyl-modified polybutadiene in a mass ratio of 3:1.

[0021] In a preferred embodiment of the present invention, the maleic anhydride-modified polybutadiene has a 1,2 vinyl content of 18-33%, a number-average molecular weight of 5000-5500, and a number of functional groups of 5-9.

[0022] Preferably, the maleic anhydride-modified polybutadiene has a 1,2 vinyl content of 18-33%, a number-average molecular weight of 5000, and 5 functional groups.

[0023] In a preferred embodiment of the present invention, the epoxidized hydroxyl-modified polybutadiene has an ethylene oxide content of 5-5.5% and a number average molecular weight of 2500-3500.

[0024] Preferably, the epoxidized hydroxyl-modified polybutadiene has an ethylene oxide content of 5.5% and a number average molecular weight of 3000.

[0025] The insulating material provided by this invention incorporates modified polybutadiene. When the modified polybutadiene comprises maleic anhydride-modified polybutadiene and epoxidized hydroxyl-modified polybutadiene in a mass ratio of 2-3:1, the carboxyl functional groups of the maleic anhydride-modified polybutadiene and the hydroxyl groups of the epoxidized hydroxyl-modified polybutadiene can form hydrogen bonds with the polar groups of polyvinyl chloride resin, enhancing interfacial bonding. Simultaneously, the epoxy groups of the epoxidized hydroxyl-modified polybutadiene may crosslink with the polyvinyl chloride molecular chain through ring-opening reactions during the preparation of the insulating material, forming a three-dimensional network structure. This not only improves the mechanical properties of the insulating material but also further blocks the migration of benzotriazole UV absorbers, rutile nano-titanium dioxide, and hindered amine light stabilizers, thus improving UV resistance. In addition, the synergistic effect of the two also improves the low-temperature resistance of the insulating material.

[0026] Furthermore, the inventors discovered that when the 1,2-vinyl content of maleic anhydride-modified polybutadiene is 18-

[0027] When the ethylene oxide content of polybutadiene modified with epoxidized hydroxyl groups is 5-5.5% and the number average molecular weight is 5000-5500, the insulation material has better performance.

[0028] In a preferred embodiment of the present invention, the filler is selected from at least one of nano-calcium carbonate, nano-carbon black, nano-mica powder, and nano-talc powder.

[0029] In a preferred embodiment of the present invention, the lubricant is selected from at least one of calcium stearate, magnesium stearate, and zinc stearate.

[0030] In a preferred embodiment of the present invention, the antioxidant is selected from at least one of antioxidant 168, antioxidant 1010 and antioxidant 1024.

[0031] In a preferred embodiment of the present invention, the plasticizer is selected from at least one of epoxidized soybean oil, dioctyl phthalate, and dibutyl phthalate.

[0032] The second aspect of the present invention provides a method for preparing an ultraviolet-resistant insulating material, comprising the following steps: (1) mixing polyvinyl chloride resin, modified polybutadiene, plasticizer, filler, composite ultraviolet-resistant composition, antioxidant, and lubricant to obtain a compound;

[0033] (2) The mixture is melt-blended, extruded and granulated using a twin-screw extruder to obtain the final product.

[0034] In a preferred embodiment of the present invention, the mixing temperature in step (1) is 80-100°C and the mixing time is 1-2 hours.

[0035] In a preferred embodiment of the present invention, the extrusion process of the twin-screw extruder in step (2) is as follows: Zone 1 100-110℃, Zone 2 110-120℃, Zone 3 120-130℃, Zone 4 125-135℃, Zone 5 130-140℃, Zone 6 125-135℃, Zone 7 135-140℃, Zone 8 130-135℃, Zone 9 125-130℃; the screw speed is 400-500 r / min.

[0036] A third aspect of the present invention provides the application of an ultraviolet-resistant insulating material in cables for electrical equipment.

[0037] The application described in this invention refers to the use of insulating materials as insulation layers or sheathing layers for cables used in electrical equipment.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] This invention utilizes a specific polyvinyl chloride resin combined with a specific UV-resistant composition (benzotriazole UV absorber, rutile nano-titanium dioxide, hindered amine light stabilizer, and fluoropolymer processing aid) and specific modified polybutadiene (maleic anhydride-modified polybutadiene and epoxidized hydroxyl-modified polybutadiene). The resulting insulating material exhibits a tensile strength greater than 20 MPa and an elongation at break greater than 300%. After 2500 hours of UV irradiation, both the tensile strength retention rate and elongation at break are greater than 90%. At -40°C, the elongation at break is greater than 60%, and the resistivity is greater than 3 × 10⁻⁶. 13 Ω·m. Detailed Implementation

[0040] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific implementation schemes are now described in detail.

[0041] The present invention will be further described below with reference to embodiments, but the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in the various embodiments of the present invention can be combined with each other as long as they do not conflict with each other.

[0042] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available or prepared by conventional methods in the art.

[0043] Polyvinyl chloride resin 1: Average degree of polymerization is 1030±50, residual vinyl chloride monomer content is 1ppm, impurity particle count is ≤10 / 100g, and fish eye count (4min) is ≤10 / 400cm. 2 It is sourced from Tianjin Bohua Chemical Development Co., Ltd., model: DP-1030(K66R).

[0044] Polyvinyl chloride resin 2: average degree of polymerization 981-1080, residual vinyl chloride monomer content 1ppm, impurity particle count ≤30 / 100g, fish eye count (4min) ≤20 / 400cm 2 It is from Tianjin Bohua Chemical Development Co., Ltd., model: DG-1000P.

[0045] Polyvinyl chloride resin 3: average degree of polymerization 1120-1235, residual vinyl chloride monomer content 5ppm, impurity particle count ≤16 / 100g, fish eye count (4min) ≤20 / 400cm 2 It originates from Shaanxi Beiyuan Chemical Group Co., Ltd., and its model number is BYDL1200.

[0046] Maleic anhydride-modified polybutadiene 1:1,2-vinyl content 18-33%, number average molecular weight 5000, functional group number 5, sourced from Ricon Chemical (Wuxi) Co., Ltd., brand name: Ricon.

[0047] 131MA10.

[0048] Maleic anhydride-modified polybutadiene 2:1,2-vinyl content 18-33%, number average molecular weight 5500, functional group number 9, sourced from Ricon Chemical (Wuxi) Co., Ltd., brand name: Ricon.

[0049] 131MA17.

[0050] The maleic anhydride-modified polybutadiene 3:1,2-vinyl content is 18-33%, the number average molecular weight is 5300, and the number of functional groups is 2. It is sourced from Liten Chemical (Wuxi) Co., Ltd., and the brand name is Ricon 131MA5.

[0051] Epoxidized hydroxyl-modified polybutadiene 1: ethylene oxide content 5.5%, number average molecular weight 3000, sourced from Liten Chemical (Wuxi) Co., Ltd., brand name: 700i.

[0052] Epoxidized hydroxyl-modified polybutadiene 2: ethylene oxide content 5.5%, number average molecular weight 1450, sourced from Liten Chemical (Wuxi) Co., Ltd., brand name: 605E.

[0053] Hydroxyl-terminated polybutadiene: number average molecular weight 2800, sourced from Liten Chemical (Wuxi) Co., Ltd., brand name: R45V.

[0054] Epoxidized soybean oil: sourced from Zhejiang Xingbang Polymer Materials Co., Ltd., brand name: Greensoft H Special Epoxidized Soybean Oil.

[0055] The nano-calcium carbonate is sourced from Shandong Yuxin Nanotechnology Co., Ltd., with an average particle size of 65±5nm.

[0056] Benzotriazole UV absorber: 2-(2H-benzotriazole-2-yl)-4,6-diterpentylphenol; Brand: BASF; Model: BASF Tinuvin 328.

[0057] Hindered amine light stabilizer: Light stabilizer 119; Brand: BASF; Model: CHIMASSORB 119.

[0058] Rutile nano-titanium dioxide 1: Particle size 50-60nm, sourced from Zhejiang Zhitai Nano-Micro New Materials Co., Ltd., model: ZT-T60.

[0059] Rutile nano-titanium dioxide 2: Particle size 15-20nm, sourced from Zhejiang Zhitai Nanomaterials Co., Ltd., model: ZT-T15.

[0060] Rutile nano titanium dioxide 3: Particle size is 200nm, sourced from Zhejiang Zhitai Nanomaterials Co., Ltd., model: ZT-T200.

[0061] Fluoropolymer processing aids: sourced from Shanghai Luju Polymer Technology Co., Ltd., brand name: 9028.

[0062] Antioxidant 1024 (CAS No.: 32687-78-8): sourced from Chenghe Technology Co., Ltd. Calcium stearate: sourced from Zhongshan Huamingtai Technology Co., Ltd., model: BS-3818. Examples 1-8: A UV-resistant insulating material, the composition of which, by weight, is shown in Table 1:

[0063] Table 1

[0064]

[0065]

[0066] Comparative Examples 1-4: A UV-resistant insulating material, the composition of which is shown in Table 2 by mass parts:

[0067] Table 2

[0068]

[0069] The preparation method of the UV-resistant insulating material described in Examples 1-8 and Comparative Examples 1-4 is as follows:

[0070] (1) Polyvinyl chloride resin, modified polybutadiene, plasticizer, filler, composite UV-resistant composition, antioxidant and lubricant are mixed to obtain a compound;

[0071] (2) The mixture is melt-blended, extruded and granulated using a twin-screw extruder to obtain the final product.

[0072] The mixing temperature in step (1) is 900℃ and the mixing time is 2h.

[0073] The extrusion process of the twin-screw extruder in step (2) is as follows: Zone 1 105℃, Zone 2 115℃, Zone 3 125℃, Zone 4 130℃, Zone 5 135℃, Zone 6 130℃, Zone 7 140℃, Zone 8 130℃, Zone 9 130℃; the screw speed is 400r / min.

[0074] Performance testing:

[0075] 1. Tensile strength: Tested according to the standard method of GB / T 2951.11-2008.

[0076] 2. Elongation at break: Tested according to the standard method of GB / T 2951.11-2008.

[0077] 3. UV resistance: A 2500-hour UV irradiation test was conducted according to Method A, Cycle No. 1 in GB / T 16422.3-2022 standard; after the UV irradiation test, the tensile strength and elongation at break were tested according to the standard method of GB / T 2951.11-2008, and the tensile strength retention rate and elongation at break retention rate were calculated.

[0078] Tensile strength retention rate = (Tensive strength after UV irradiation test / Tensile strength before UV irradiation test) × 100%;

[0079] Elongation at break retention rate = Elongation at break after UV irradiation test / Elongation at break before UV irradiation test × 100%.

[0080] 4. Low temperature resistance: The elongation at break at -40℃ is tested according to GB / T 2951.14-2008 standard.

[0081] 5. Resistivity: The resistivity was measured using a resistivity meter at 25℃ and 1000V.

[0082] Performance test results are shown in Table 3.

[0083] Table 3

[0084]

[0085]

[0086] As shown in Table 3, the UV-resistant insulating material provided by this invention has a tensile strength greater than 20 MPa and an elongation at break greater than 300%; after 2500 hours of UV irradiation, both the tensile strength retention rate and the elongation at break are greater than 90%; the elongation at break at -40℃ is greater than 60%; and the resistivity is greater than 3 × 10⁻⁶. 13 Ω·m.

[0087] Examples 2 and 3 demonstrate that using specific polyvinyl chloride resins can significantly improve the UV resistance and low-temperature resistance of insulating materials.

[0088] Examples 4 and 5 show that using specific maleic anhydride-modified polybutene is beneficial to improving the mechanical strength, UV resistance, and low-temperature resistance of insulating materials.

[0089] As can be seen from Example 6, the use of specific epoxidized hydroxyl-modified polybutadiene is beneficial to improving the mechanical strength, UV resistance and low-temperature resistance of insulating materials.

[0090] As can be seen from Examples 7-8, using specific rutile nano-titanium dioxide is beneficial to improving the UV resistance of insulating materials.

[0091] Comparative Example 1 shows that replacing epoxidized hydroxyl-modified polybutadiene with hydroxyl-terminated polybutadiene significantly reduces the UV resistance of the insulating material.

[0092] Comparative Examples 2 and 3 show that maleic anhydride-modified polybutene and epoxidized hydroxyl-modified polybutadiene can synergistically improve the mechanical properties, UV resistance, and low-temperature resistance of insulating materials.

[0093] Comparative Example 4 shows that without the addition of fluoropolymer processing aids, the UV resistance of the insulating material is significantly reduced.

[0094] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A UV-resistant insulating material, characterized in that, By weight, it comprises the following components: 100 parts polyvinyl chloride resin, 5-10 parts modified polybutadiene, 10-20 parts plasticizer, 10-20 parts filler, 3-6 parts composite UV-resistant composition, 0.2-0.8 parts antioxidant, and 1-3 parts lubricant. The polyvinyl chloride resin has an average degree of polymerization of 900-1100, a residual vinyl chloride monomer content of ≤5ppm, an impurity particle count of ≤20 particles / 100g, and a fisheye count of ≤20 particles / 400cm. 2 ; The modified polybutadiene comprises maleic anhydride-modified polybutadiene and epoxidized hydroxyl-modified polybutadiene in a mass ratio of 2-3:

1. The plasticizer is epoxidized soybean oil; The composite UV-resistant composition comprises a benzotriazole UV absorber, rutile nano-titanium dioxide, a hindered amine light stabilizer, and a fluoropolymer processing aid in a mass ratio of 1-3:5-8:1-3:10-20. The lubricant is calcium stearate.

2. The UV-resistant insulating material according to claim 1, characterized in that, The polyvinyl chloride resin has an average degree of polymerization of 1030±50, a residual vinyl chloride monomer content of 1ppm, an impurity particle count of ≤10 particles / 100g, and a fisheye count of ≤10 particles / 400cm. 2 .

3. The UV-resistant insulating material according to claim 2, characterized in that, The rutile nano-titanium dioxide has a particle size of 10-70 nm.

4. The UV-resistant insulating material according to claim 3, characterized in that, The maleic anhydride-modified polybutadiene has a 1,2 vinyl content of 18-33%, a number-average molecular weight of 5000-5500, and 5-9 functional groups.

5. The UV-resistant insulating material according to claim 4, characterized in that, The maleic anhydride-modified polybutadiene has a 1,2 vinyl content of 18-33%, a number-average molecular weight of 5000, and 5 functional groups.

6. The UV-resistant insulating material according to claim 5, characterized in that, The epoxidized hydroxyl-modified polybutadiene has an ethylene oxide content of 5-5.5% and a number average molecular weight of 2500-3500.

7. A method for preparing the UV-resistant insulating material according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Polyvinyl chloride resin, modified polybutadiene, plasticizer, filler, composite UV-resistant composition, antioxidant and lubricant are mixed to obtain a compound; (2) The mixture is melt-blended, extruded and granulated using a twin-screw extruder to obtain the final product.

8. The use of the UV-resistant insulating material according to any one of claims 1-6 in cables for electrical equipment.

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