A low-smoke and halogen-free flame-retardant cable compound and its preparation method

Abstract

The present application relates to a low-smoke and halogen-free flame-retardant cable material and a preparation method thereof, belonging to the technical field of polymer materials, and comprising the following raw materials in parts by weight: 30-40 parts of polyethylene resin; 5-10 parts of silane-modified polyether resin; 5-10 parts of compatibilizer; 40-50 parts of flame retardant; 1 part of antioxidant; 1 part of carbon black masterbatch; 1 part of silicone. The low-smoke and halogen-free flame-retardant cable material in the present application solves the problems of poor fluidity and difficulty in injection molding of traditional halogen-free flame-retardant polyolefin materials, improves the light transmittance and takes into account other necessary electrical properties, achieves a breakthrough in the injection molding process, and improves the safety and reliability of pre-branched cables.

Description

Technical Field

[0001] This application relates to the technical field of polymer materials, and more specifically, to a low-smoke and halogen-free flame-retardant cable material and a preparation method thereof. Background Art

[0002] Prefabricated branch cables are mainly designed and manufactured from a main cable, branch lines, and branch connectors. The main cable and branch lines use flame-retardant polyolefin materials as the insulation or sheath materials of the cable. The branch connectors should also use halogen-free and low-smoke flame-retardant polyolefin materials in terms of performance requirements. Otherwise, gaps will appear at the joints bonded together during the installation and laying at the construction site, resulting in serious quality problems.

[0003] However, in practical applications, especially in the injection molding process of prefabricated branch cable connectors, the poor fluidity of halogen-free and low-smoke flame-retardant polyolefin materials has become a common problem in the industry. Although the existing halogen-free and low-smoke flame-retardant polyolefin materials can meet the basic flame-retardant requirements, the poor fluidity makes it difficult to guarantee the quality of injection-molded parts. In particular, air gaps are likely to form at the connection parts, reducing the overall performance of prefabricated branch cables.

[0004] Therefore, there is an urgent need to develop a low-smoke and halogen-free flame-retardant cable material with improved fluidity and light transmittance. Summary of the Invention

[0005] This application provides a low-smoke and halogen-free flame-retardant cable material and a preparation method thereof, which solve the problems of poor fluidity and difficulty in injection molding of traditional halogen-free flame-retardant polyolefin materials, improve the light transmittance and take into account other necessary electrical properties, achieve a breakthrough in the injection molding process, and improve the safety and reliability of prefabricated branch cables.

[0006] In the first aspect of this application, a low-smoke and halogen-free flame-retardant cable material is provided. The preparation raw materials of the cable material include, by weight:

[0007] 30-40 parts of polyethylene resin;

[0008] 5-10 parts of silane-modified polyether resin;

[0009] 5-10 parts of compatibilizer;

[0010] 40-50 parts of flame retardant;

[0011] 1 part of antioxidant;

[0012] 1 part of carbon black masterbatch;

[0013] 1 part of silicone.

[0014] By adopting the above technical solutions, the addition of the silane-modified polyether resin can reduce the crystallinity of the polyethylene resin, thereby reducing light scattering caused by the crystalline regions and improving the light transmittance; the polar groups of the silane-modified polyether resin can improve the interfacial compatibility between the polymer and the filler or other additives, reduce interfacial defects, and thus reduce light scattering; by reducing light scattering, improving interfacial compatibility and reducing crystallinity, the silane-modified polyether resin can effectively improve the light transmittance of the cable material.

[0015] Optionally, the polyethylene resin is selected from one or more of low-density polyethylene resin, linear low-density polyethylene resin, and metallocene linear low-density polyethylene resin.

[0016] Optionally, the silane-modified polyether resin is selected from one or more of Jiangsu Ruiyang Antai 200D and SAX260.

[0017] Optionally, the compatibilizer is selected from one or more of polyethylene glycol grafted polyethyleneimine and maleic anhydride grafted polyethylene.

[0018] By adopting the above technical solutions, the flexibility and low melt viscosity of the polyethylene glycol segment can reduce the friction between the polyethylene molecular chains and improve the fluidity of the material; polyethylene glycol grafted polyethyleneimine and maleic anhydride grafted polyethylene act synergistically, and through the dual mechanisms of plasticization and interfacial lubrication, significantly improve the fluidity of the cable material. The two act synergistically to improve the dispersion and interfacial compatibility of the filler, make the material more uniform, and also significantly improve the light transmittance.

[0019] Optionally, the antioxidant is selected from one or more of phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0020] By adopting the above technical solutions, the antioxidant is used to prevent the material from degrading at high temperatures, thereby ensuring the long-term stability and electrical properties of the material.

[0021] Optionally, the flame retardant is selected from one or more of magnesium hydroxide, high-flame-retardant red phosphorus, and antimony trioxide.

[0022] By adopting the above technical solutions, magnesium hydroxide, high-flame-retardant red phosphorus, and antimony trioxide act synergistically to enhance the flame retardant performance of the material.

[0023] The second aspect of the present application provides a preparation method of the above-mentioned low-smoke and halogen-free flame-retardant cable material, including the following steps:

[0024] Step 1: Mix the polyethylene resin, silane-modified polyether resin, flame retardant, carbon black masterbatch, and antioxidant evenly, add the compatibilizer and silicone, and continue to mix to obtain a mixture;

[0025] Step 2: Feed the mixture into a screw extruder for extrusion granulation to obtain the cable material.

[0026] The third aspect of the present application provides the use of the above-mentioned low-smoke halogen-free flame-retardant cable material for preparing the branch connection body of a branch cable.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] The present application significantly improves the fluidity of the low-smoke halogen-free flame-retardant cable material, making the material more suitable for the injection molding process of the pre-branch cable connection body, reducing the air gap phenomenon at the connection part, and improving the safety and reliability of the cable.

[0029] The light transmittance of the material of the present application reaches more than 80%, which is much higher than the general performance of similar products, providing a strong guarantee for unobstructed vision in case of emergencies such as fires.

[0030] By optimizing the formula, the present application successfully achieves the balance between high light transmittance and other necessary properties (such as flame retardancy and mechanical strength), meets the requirements of "JB / T10436-2006 Rated voltage 0.6 / 1kv (Um = 1.2kv) Copper core plastic insulated pre-branch cable" for material properties, and expands the application scope and market share of the product. Detailed implementation manners

[0031] The present invention will be specifically described below through examples. It is necessary to point out here that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention still fall within the protection scope of the present invention.

[0032] Example 1

[0033] A low-smoke halogen-free flame-retardant cable material, which comprises the following components in parts by weight: 30 parts of polyethylene resin; 7 parts of silane-modified polyether resin 200D; 10 parts of compatibilizer (composed of 5 parts of polyethylene glycol grafted polyethyleneimine and 5 parts of maleic anhydride grafted polyethylene); 1 part of carbon black masterbatch; 30 parts of magnesium hydroxide; 5 parts of high flame-retardant red phosphorus; 15 parts of antimony trioxide; 1 part of silicone; 1 part of antioxidant.

[0034] The polyethylene resin includes low-density polyethylene resin, linear low-density polyethylene resin, and metallocene linear low-density polyethylene resin, and the weight ratio is 1:1:1.

[0035] The silane-modified polyether resin 200D is purchased from Jiangsu Ruiyang Antai.

[0036] The antioxidant is antioxidant 1790 and antioxidant 168, and the weight ratio is 3:1.

[0037] This example also provides a method for preparing the cable material as described above, including the following steps:

[0038] Step 1: Polyethylene resin, silane-modified polyether resin, flame retardant, carbon black masterbatch, and antioxidant are mixed evenly, and a compatibilizer and silicone are added, and mixing is continued to obtain a mixture;

[0039] Step 2: The mixture is fed into a screw extruder for extrusion granulation to obtain the cable material; the length-diameter ratio of the twin-screw extruder is 44:1; the temperatures of each section of the twin-screw extruder body are successively: 80°C to 100°C, 125°C to 130°C, 130°C to 135°C, 135°C to 140°C, 140°C to 145°C, 145°C to 150°C, 150°C to 155°C; the head temperature is 145°C to 150°C.

[0040] Example 2

[0041] A low-smoke and halogen-free flame-retardant cable material, which includes the following components in parts by weight: 40 parts of polyethylene resin; 5 parts of silane-modified polyether resin 200D; 5 parts of compatibilizer (3 parts of polyethylene glycol-grafted polyethyleneimine and 2 parts of maleic anhydride-grafted polyethylene); 1 part of carbon black masterbatch; 30 parts of magnesium hydroxide; 2 parts of high-flame-retardant red phosphorus; 15 parts of antimony trioxide; 1 part of silicone; 1 part of antioxidant. The rest is the same as in Example 1.

[0042] Example 3

[0043] A low-smoke and halogen-free flame-retardant cable material, which includes the following components in parts by weight: 40 parts of polyethylene resin; 10 parts of silane-modified polyether resin 200D; 7 parts of compatibilizer (composed of 4 parts of polyethylene glycol-grafted polyethyleneimine and 3 parts of maleic anhydride-grafted polyethylene); 1 part of carbon black masterbatch; 25 parts of magnesium hydroxide; 2 parts of high-flame-retardant red phosphorus; 13 parts of antimony trioxide; 1 part of silicone; 1 part of antioxidant. The rest is the same as in Example 1.

[0044] Example 4

[0045] A low-smoke and halogen-free flame-retardant cable material, the silane-modified polyether resin uses SAX260 (purchased from Nippon Zeon Chemical Co., Ltd.), and the rest is the same as in Example 1.

[0046] Example 5

[0047] A low-smoke and halogen-free flame-retardant cable material, the silane-modified polyether resin uses SAX260 and 200D with a weight ratio of 1:1, and the rest is the same as in Example 1.

[0048] Example 6

[0049] A low-smoke and halogen-free flame-retardant cable compound, with the compatibilizer being polyethylene glycol grafted polyethyleneimine, and the rest being the same as in Example 1.

[0050] Comparative Example 1

[0051] A low-smoke and halogen-free flame-retardant cable compound, with the compatibilizer being maleic anhydride grafted polyethylene, and the rest being the same as in Example 1.

[0052] Comparative Example 2

[0053] A low-smoke and halogen-free flame-retardant cable compound, which comprises the following components in parts by weight: 37 parts of polyethylene resin; 10 parts of compatibilizer (composed of 5 parts of polyethylene glycol grafted polyethyleneimine and 5 parts of maleic anhydride grafted polyethylene); 1 part of carbon black masterbatch; 30 parts of magnesium hydroxide; 5 parts of high-flame-retardant red phosphorus; 15 parts of antimony trioxide; 1 part of silicone; 1 part of antioxidant. The rest is the same as in Example 1.

[0054] Comparative Example 3

[0055] A low-smoke and halogen-free flame-retardant cable compound, wherein the polyethylene resin is only low-density polyethylene resin, and the rest is the same as in Example 1.

[0056] Performance evaluation

[0057] For the cable compounds provided in the examples and comparative examples, the specimens should be prepared by the compression molding method or other suitable methods. The tubular sample materials can be cut and weighed, and preheated without pressure in a hydraulic press at 170 °C - 180 °C for 60 s. Then, it is molded under pressure for 4 min, and the pressure of the hydraulic press is greater than 15 MPa. Pressurize and cool to room temperature. The test pieces should be flat, smooth, with uniform thickness and no bubbles. Then, immerse the test pieces in a water bath at a temperature of 90 °C - 95 °C for 0.5 - 4 hours. After warm water cross-linking, the test pieces should still remain flat. The test results of performance characterization are shown in Table 1.

[0058] Table 1

[0059] Test Items Melt Flow Rate (MFR) at 170℃, 5kg Smoke Density (Flaming) Light Transmittance of Pre-branched Cable Connectors during Combustion Unit g / 10min / % Test Method ISO 1133 GB8323 / T IEC61034-2-2013 Example 1 7.2 76 86 Example 2 6.3 72 76 Example 3 6.6 75 81 Example 4 7.1 74 84 Example 5 7.5 73 88 Example 6 6.1 77 78 Comparative Example 1 2.6 72 63 Comparative Example 2 4.4 73 54 Comparative Example 3 5.6 75 71

[0060] Compared with Comparative Examples 1 - 3, Examples 1 - 6 solved the problems of poor fluidity and difficulty in injection molding of traditional halogen-free flame-retardant polyolefin materials by reasonably matching the types and proportions of raw materials, significantly improved the light transmittance, and took into account other necessary electrical properties (in this application, the smoke density is used as a representative property), achieved a breakthrough in the injection molding process, and improved the safety and reliability of pre-branched cables.

[0061] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to claim the broadest scope conceivable, and the embodiments presented herein are merely illustrative of selected embodiments from all possible combinations of embodiments. Thus, it is the intention of the applicant that the appended claims not be limited by the selection of examples illustrating the features of the invention. Some of the numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should, where possible, be construed as being covered by the appended claims.

Claims

1. A low-smoke and halogen-free flame-retardant cable compound, characterized in that, The raw materials for preparing the cable compound, by weight, include: 30 - 40 parts of polyethylene resin; 5 - 10 parts of silane - modified polyether resin; 5 - 10 parts of compatibilizer; 40 - 50 parts of flame retardant; 1 part of antioxidant; 1 part of carbon black masterbatch; 1 part of silicone; The polyethylene resin is selected from one or more of low - density polyethylene resin, linear low - density polyethylene resin, and metallocene linear low - density polyethylene resin; The silane - modified polyether resin is selected from one or more of Jiangsu Ruiyang Antai 200D and Nippon Kayaku SAX260; The compatibilizer is composed of polyethylene glycol - grafted polyethyleneimine and maleic anhydride - grafted polyethylene.

2. The low-smoke and halogen-free flame-retardant cable compound according to claim 1, wherein The antioxidant is selected from one or more of phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

3. A low-smoke and halogen-free flame-retardant cable material according to claim 1, characterized in that The flame retardant is selected from one or more of magnesium hydroxide, high - flame - retardant red phosphorus, and antimony trioxide.

4. A preparation method of a low-smoke and halogen-free flame-retardant cable material as described in any one of claims 1-3, characterized in that, It includes the following steps: Step 1: Mix the polyethylene resin, silane - modified polyether resin, flame retardant, carbon black masterbatch, and antioxidant evenly, add the compatibilizer and silicone, and continue mixing to obtain a mixture; Step 2: Feed the mixture into a screw extruder for extrusion granulation to obtain the cable compound.

5. Use of a low - smoke and halogen - free flame - retardant cable compound according to any one of claims 1 - 3 for preparing a branch connection body of a branch cable.