A non-cross-linked PVC cable and its preparation method

Abstract

The present application provides a non-cross-linked PVC cable and a preparation method thereof, which comprises the following components, measured by mass: 100 parts of PVC resin, 45 to 55 parts of plasticizer, 3.5 to 4.5 parts of epoxy soybean oil, 7 to 11 parts of stabilizer, 20 to 30 parts of ultrafine calcium carbonate and 2.2 to 2.5 parts of antimony trioxide; the PVC resin comprises PVC-1300 with an average degree of polymerization of 1300 and PVC-2500 with an average degree of polymerization of 2500, and the mass ratio of PVC-1300 to PVC-2500 in the PVC resin is 1:0.8 to 1.2. While adopting an environmentally friendly non-cross-linked form, it also has the advantage of improving the heat resistance grade.

Description

Technical Field

[0001] The invention relates to a non-cross-linked PVC cable and a preparation method thereof. Background Art

[0002] PVC cable material is a kind of plastic particles made of polyvinyl chloride resin as the main body, with various additives and fillers added, mixed and granulated. It is mainly used for the outer sheath of wires and cables and has good mechanical properties and electrical insulation properties.

[0003] At present, there are many kinds of PVC cable materials on the market, but they are mainly suitable for ordinary civilian cable materials. Most of their heat resistance grades are 70, 80, and 90°C, but they are not suitable for heat resistance grades of 125°C or even higher, so their heat resistance needs to be improved. Summary of the invention

[0004] The first object of the present invention is to provide a non-cross-linked PVC cable which is environmentally friendly and non-cross-linked while having the advantage of improving the heat resistance level.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A non-cross-linked PVC cable comprises the following components by mass: 100 parts of PVC resin, 45-55 parts of plasticizer, 3.5-4.5 parts of epoxy soybean oil, 7-11 parts of stabilizer, 20-30 parts of ultrafine calcium carbonate and 2.2-2.5 parts of antimony trioxide; the PVC resin comprises PVC-1300 with an average degree of polymerization of 1300 and PVC-2500 with an average degree of polymerization of 2500, and the mass ratio of PVC-1300 to PVC-2500 in the PVC resin is 1:0.8-1.2.

[0007] Preferably, the plasticizer comprises tetraoctyl pyromellitate.

[0008] Preferably, the plasticizer comprises tetraoctyl pyromellitic acid and 1-butyl 3-methylimidazolium hexafluorophosphate in a mass ratio of 1:0.09-0.12.

[0009] Preferably, the stabilizer comprises calcium lanthanum hydrotalcite.

[0010] Preferably, the stabilizer comprises calcium lanthanum hydrotalcite, zinc stearate, stearic acid and β-diketone compound in a mass ratio of 1:0.09-0.12:0.09-0.12:0.09-0.12.

[0011] Preferably, the non-cross-linked PVC cable further comprises other additives, which include 3 to 5 parts of PE wax and 1 to 3 parts of ethylene-vinyl acetate copolymer by weight, and the vinyl acetate content of the ethylene-vinyl acetate copolymer is less than 5%.

[0012] The second object of the present invention is to provide a method for preparing a non-cross-linked PVC cable.

[0013] The above technical objectives of the present invention are achieved through the following technical solutions:

[0014] The method for preparing a non-crosslinked PVC cable comprises the following steps: uniformly mixing a formula amount of PVC resin, a plasticizer, a stabilizer, ultrafine calcium carbonate and antimony trioxide, adding a formula amount of epoxy soybean oil and mixing uniformly to obtain a mixed sample, and introducing the mixed sample into a double-roll calender and plasticizing it into a sheet at 155-170°C.

[0015] The technical effects of the present invention are mainly reflected in the following aspects:

[0016] PVC-1300 has good processing performance, electrical properties, mechanical properties and heat resistance, but does not meet the aging resistance requirements at 125°C. This application uses it in combination with PVC-2500. The entanglement points between the random molecular chains in PVC-2500 have similar cross-linking structures, showing higher elasticity, better mechanical properties and high and low temperature resistance, but the flowability is slightly worse than that of PVC-1300 resin, the processing temperature range is narrow, and the processing technology control requirements are strict. The combination of the two can comprehensively improve the heat resistance and scope of use;

[0017] In the present application, the addition of tetraoctyl pyromellitic acid can effectively improve its heat resistance and aging resistance. Replacing tetraoctyl pyromellitic acid with tetraoctyl pyromellitic acid and 1-butyl-3-methylimidazolium hexafluorophosphate can further increase its aging resistance.

[0018] In the present application, the addition of calcium lanthanum hydrotalcite can meet the requirements of 125°C cable material, and its performance can be further improved by combining it with zinc stearate, stearic acid and β-diketone compounds. DETAILED DESCRIPTION

[0019] Example 1: A non-cross-linked PVC cable is obtained by the following preparation method, comprising the following steps: uniformly mixing a formulated amount of PVC resin, a plasticizer, a stabilizer, ultrafine calcium carbonate, antimony trioxide and other additives, adding a formulated amount of epoxy soybean oil and mixing uniformly to obtain a mixed sample, introducing the mixed sample into a double-roll calender and plasticizing it into sheets at 155-170°C (Example 1 is prepared at 165°C).

[0020] The PVC resins selected in Example 1 include PVC-1300 with an average degree of polymerization of 1300 and PVC-2500 with an average degree of polymerization of 2500. The mass ratio of PVC-1300 to PVC-2500 is 1:1. PVC-1300 is purchased from Hanwha Chemical (Ningbo) Co., Ltd., and PVC-2500 is purchased from Tangshan Sanyou Chemical Co., Ltd.

[0021] Tetraoctyl pyromellitic acid was purchased from Tesco Chemical (Hubei) Co., Ltd., and 1-butyl-3-methylimidazole hexafluorophosphate was purchased from Qingdao Oriko New Materials Technology Co., Ltd. Epoxidized soybean oil was purchased from Shandong Huasheng New Materials Co., Ltd., with an epoxy value of more than 6.2. Calcium lanthanum hydrotalcite was purchased from Qingdao Tengyun Chemical Technology Co., Ltd. Ultrafine calcium carbonate was purchased from Nanzhao County Jijin Mineral Co., Ltd., 5.5μm, 2500 mesh. PE wax was purchased from Hebei Qinhao Chemical. Ethylene-vinyl acetate copolymer was purchased from DuPont, USA, and the vinyl acetate content of ethylene-vinyl acetate copolymer was less than 5%.

[0022] In Example 1, a total of 5 samples were prepared, and the sample formula information is shown in Table 1.

[0023] Table 1 Formulation information of Example 1 (unit: mass fraction).

[0024] Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 PVC resin 100 100 100 100 100 Tetraoctyl pyromellitate 45 55 48 48 48 1-Butyl-3-methylimidazolium hexafluorophosphate 0 0 0 4.8 4.8 Epoxidized soybean oil 3.5 4.5 4.0 4.0 4.0 Calcium lanthanum hydrotalcite 7 10 8 8 8 Zinc stearate 0 0 0 0.8 0.8 Stearic acid 0 0 0 0.8 0.8 β-Diketone compounds 0 0 0 0.8 0.8 Ultrafine Calcium Carbonate 20 30 25 25 25 Antimony trioxide 2.2 2.5 2.4 2.4 2.4 PE wax 0 0 0 0 4 Ethylene-vinyl acetate copolymer 0 0 0 0 2

[0025] Performance Testing

[0026] (1) Aging performance test

[0027] Examples 3-5 were aged at 158°C for 168 hours respectively. The tensile strength and elongation at break before and after aging were tested, and their change rates were calculated. The results are shown in Table 2.

[0028] Table 2

[0029] Sample 3 Sample 4 Sample 5 Tensile strength before aging / MPa 18.5 18.6 18.8 Tensile strength after aging / MPa 19.6 19.4 19.1 Tensile strength change rate / % 5.9 4.3 1.6 Breaking strength elongation before aging / % 317 320 319 Elongation at break after aging / % 259 278 297 Change rate of breaking strength elongation / % 18.3 13.1 6.9

[0030] (2) Migration resistance comparison test

[0031] ① Engine oil resistance test: Immerse the test piece completely in automotive synthetic engine oil, seal it, and bake it in an oven at 80°C for 48 hours. Weigh the mass before and after baking, and divide the difference by the mass before baking to get the mass change rate (%). The following calculation method is the same.

[0032] ②Tap water resistance test: The test piece was completely immersed in water, sealed, and baked in an oven at 95°C for 72 hours. The mass before and after baking was weighed, and the mass change rate was calculated.

[0033] ③ ABS board and PS board resistance test: sandwich the test piece between two ABS boards, load 500g of silicon code, bake in an oven at 70℃ for 72h, take it out and open it to observe whether it is sticky, whether there are migration marks on the ABS board, and weigh the weight of the test piece before and after. The test method for PS board resistance is the same.

[0034] ④ PVC-U board resistance test: Compared with the ABS board resistance test, except that the oven temperature was increased to 85°C, other steps were the same. The results are shown in Table 3.

[0035] Table 3

[0036]

[0037] The samples were subjected to comprehensive performance tests and all met the performance indicators of 125℃ cable materials shown in Table 4.

[0038] Table 4

[0039] index Tensile strength / MPa ≥16.0 Elongation at break / % ≥200 -25℃ low temperature impact test ≤15 / 30 Thermal stability time at 200℃ / min ≥180 Volume resistivity at 20℃ / (Ω·m) <![CDATA[≥1.0×10 11 ]]> Dielectric strength / (MV / m) ≥20 Thermal oven aging test (158°C, 168hr) Tensile strength after aging / MPa ≥16.0 Elongation at break after aging / % ≥200 Change rate of tensile strength after aging / % ±20 Change rate of breaking strength and elongation after aging / % ±20

[0040] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A non-cross-linked PVC cable, characterized in that: The composition includes the following components by weight: 100 parts of PVC resin, 45-55 parts of plasticizer, 3.5-4.5 parts of epoxidized soybean oil, 7-11 parts of stabilizer, 20-30 parts of ultrafine calcium carbonate, 2.2-2.5 parts of antimony trioxide and other additives; The PVC resin includes PVC-1300 with an average degree of polymerization of 1300 and PVC-2500 with an average degree of polymerization of 2500, and the mass ratio of PVC-1300 to PVC-2500 in the PVC resin is 1:0.8-1.2; The plasticizer includes tetraoctyl pyromellitic acid and 1-butyl-3-methylimidazolium hexafluorophosphate in a mass ratio of 1:0.09-0.12; The stabilizer includes calcium lanthanum hydrotalcite, zinc stearate, stearic acid and β-diketone compound in a mass ratio of 1:0.09-0.12:0.09-0.12:0.09-0.12; Calculated by weight, other additives include 3 to 5 parts of PE wax and 1 to 3 parts of ethylene-vinyl acetate copolymer, and the vinyl acetate content of the ethylene-vinyl acetate copolymer is less than 5%.

2. The method for preparing a non-cross-linked PVC cable according to claim 1, characterized in that: The following steps are involved: The formulated amount of PVC resin, plasticizer, stabilizer, ultrafine calcium carbonate, antimony trioxide and other additives are mixed evenly, the formulated amount of epoxy soybean oil is added and mixed evenly to obtain a mixed sample, and the mixed sample is introduced into a double-roll calender and plasticized into sheets at 155-170°C.

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