Process for the preparation of a flame-retardant polyethylene cable material of class a

Abstract

The application discloses a kind of A class flame-retardant polyethylene cable material, by the following weight parts component composition: melt flow rate is 3~8g / 10min high density polyethylene resin 100 parts, linear low density polyethylene resin 35~55 parts, maleic anhydride graft ethylene vinyl acetate 5~15 parts, carbon black 3~5 parts, aluminum hydroxide 50~60 parts, magnesium hydroxide 10~30 parts, phosphorus-nitrogen flame retardant 2~8 parts, metal soap lubricant 3~6 parts, antioxidant 0.5~2 parts, diisononyl phthalate 1~5 parts, lauryl acrylate 2~5 parts, hyperbranched polyethylene imine 1~3 parts.The A class flame-retardant polyethylene cable material of the application guarantees flame-retardant performance at the same time, prolongs flame-retardant polyethylene environmental stress cracking time, exceeds 260 hours, so that the flame-retardant polyethylene cable material forms cable sheath, has better environmental stress cracking resistance performance.

Description

Technical Field

[0001] This invention relates to the field of cable material technology, and in particular to a method for preparing Class A flame-retardant polyethylene cable material. Background Technology

[0002] Polyethylene sheathing material is a commonly used, lightweight, non-toxic, environmentally friendly thermoplastic with excellent electrical insulation properties, widely used in the wire and cable industry. Previously, most wires and cables were made of PVC, which is toxic, harmful, and environmentally unfriendly; burning PVC releases large amounts of toxic and harmful gases, causing significant damage. Low-smoke halogen-free polyolefin cables, in order to meet the requirements of low smoke and halogen-free properties, incorporate large amounts of inorganic flame retardants, resulting in a significant decrease in the material's crack resistance, failing to meet the requirements. Therefore, it is necessary to develop flame-retardant polyethylene cable materials that ensure good flame retardancy while simultaneously possessing excellent crack resistance. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing Class A flame-retardant polyethylene cable material. The Class A flame-retardant polyethylene cable material obtained by this method, while ensuring flame-retardant performance, extends the environmental stress cracking resistance time of flame-retardant polyethylene to more than 260 hours, so that the flame-retardant polyethylene cable material has better environmental stress cracking resistance after forming the cable sheath.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing Class A flame-retardant polyethylene cable material, comprising the following steps:

[0005] Step 1: Add 100 parts of high-density polyethylene resin with a melt flow rate of 3~8 g / 10min, 35~55 parts of linear low-density polyethylene resin, 5~15 parts of maleic anhydride-grafted vinyl acetate, 3~5 parts of carbon black, 50~60 parts of aluminum hydroxide, 10~30 parts of magnesium hydroxide, 2~8 parts of phosphorus-nitrogen flame retardant, and 3~6 parts of metal soap lubricant to a mixer, and then start mixing until the material temperature reaches 120℃~150℃ to obtain the first mixture.

[0006] Step 2: Add 0.5-2 parts of antioxidant, 1-5 parts of diisononyl phthalate, 2-5 parts of lauryl acrylate, and 1-3 parts of hyperbranched polyethyleneimine to the first mixture, and mix in an internal mixer at a mixing temperature of 100-110℃ to obtain the second mixture.

[0007] Step 3: Feed the second mixture into a twin-screw extruder and extrude and granulate it at 160~170℃ to obtain the polyethylene cable material.

[0008] The following is a further improvement to the above technical solution:

[0009] 1. In the above scheme, the metal soap lubricant is calcium stearate or zinc stearate.

[0010] 2. In the above scheme, the antioxidant is one of antioxidant 1010, antioxidant 1076, antioxidant 168, antioxidant 626, and antioxidant 300P.

[0011] 3. In the above scheme, the phosphorus-nitrogen flame retardant is at least one of melamine, melamine polyphosphate, melamine pyrophosphate, melamine orthophosphate, ammonium polyphosphate, melamine phosphate salt, di-neopentyl glycol m-phenylenediamine diphosphate, and neopentyl glycol phosphate melamine salt.

[0012] 4. In the above scheme, the melt flow rate of the linear low-density polyethylene resin is 0.05~2 g / 10min.

[0013] 5. In the above scheme, the mixing time in step one is 30-60 minutes, and the mixing time in step two is 10-15 minutes.

[0014] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0015] This invention relates to a method for preparing Class A flame-retardant polyethylene cable material. It is based on 50-60 parts aluminum hydroxide, 10-30 parts magnesium hydroxide, and 2-8 parts phosphorus-nitrogen flame retardant, with the addition of 2-5 parts lauryl acrylate and 1-3 parts hyperbranched polyethyleneimine. While ensuring flame-retardant performance, it overcomes the defect of decreased cracking performance caused by the addition of three types of flame retardants, extending the environmental stress cracking resistance time of flame-retardant polyethylene to over 260 hours. This results in the obtained flame-retardant polyethylene cable material having better environmental stress cracking resistance after being formed into a cable sheath. Detailed Implementation

[0016] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the technical solution, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0017] The present invention will be further described below with reference to embodiments:

[0018] Examples 1-4: A method for preparing Class A flame-retardant polyethylene cable material, wherein the Class A flame-retardant polyethylene cable material is composed of the following components in parts by weight, as shown in Table 1:

[0019] Table 1

[0020] ;

[0021] Includes the following steps:

[0022] Step 1: Add 100 parts of high-density polyethylene resin with a melt flow rate of 3~8 g / 10min, 35~55 parts of linear low-density polyethylene resin, 5~15 parts of maleic anhydride-grafted vinyl acetate, 3~5 parts of carbon black, 50~60 parts of aluminum hydroxide, 10~30 parts of magnesium hydroxide, 2~8 parts of phosphorus-nitrogen flame retardant, and 3~6 parts of metal soap lubricant to a mixer, and then start mixing until the material temperature reaches 120℃~150℃ to obtain the first mixture.

[0023] Step 2: Add 0.5-2 parts of antioxidant, 1-5 parts of diisononyl phthalate, 2-5 parts of lauryl acrylate, and 1-3 parts of hyperbranched polyethyleneimine to the first mixture, and mix in an internal mixer at a mixing temperature of 100-110℃ to obtain the second mixture.

[0024] Step 3: Feed the second mixture into a twin-screw extruder and extrude and granulate it at 160~170℃ to obtain the polyethylene cable material.

[0025] In Example 1, the metal soap lubricant is calcium stearate, the antioxidant is antioxidant 1010, and the phosphorus-nitrogen flame retardant is a mixture of di- and tri-cyanamide pyrophosphate and ammonium polyphosphate in a weight ratio of 1:2. The melt flow rate of the linear low-density polyethylene resin is 2 g / 10 min, and the melt flow rate of the high-density polyethylene resin is 4 g / 10 min.

[0026] In Example 2, the metal soap lubricant is zinc stearate, the antioxidant is antioxidant 626, the phosphorus-nitrogen flame retardant is melamine polyphosphate, the melt flow rate of the above linear low-density polyethylene resin is 1 g / 10 min, and the melt flow rate of the high-density polyethylene resin is 5 g / 10 min.

[0027] In Example 3, the metal soap lubricant is zinc stearate, the antioxidant is antioxidant 300P, the phosphorus-nitrogen flame retardant is melamine orthophosphate, the melt flow rate of the linear low-density polyethylene resin is 2 g / 10 min, and the melt flow rate of the high-density polyethylene resin is 4 g / 10 min.

[0028] In Example 4, the metal soap lubricant is calcium stearate, the antioxidant is antioxidant 1076, the phosphorus-nitrogen flame retardant is melamine, the melt flow rate of the linear low-density polyethylene resin is 1 g / 10 min, and the melt flow rate of the high-density polyethylene resin is 5 g / 10 min.

[0029] Comparative Examples 1-3: A method for preparing flame-retardant polyethylene cable material, wherein the flame-retardant polyethylene cable material is composed of the following components in parts by weight, as shown in Table 2:

[0030] Table 2

[0031] ;

[0032] The steps of the comparative preparation method are the same as those of the preparation method in the example.

[0033] In Comparative Examples 1 and 2, the metal soap lubricant was calcium stearate, the antioxidant was antioxidant 1010, and the phosphorus-nitrogen flame retardant was a mixture of di- and tri-cyanamide pyrophosphate and ammonium polyphosphate in a weight ratio of 1:2. The melt flow rate of the linear low-density polyethylene resin was 2 g / 10 min, and the melt flow rate of the high-density polyethylene resin was 4 g / 10 min.

[0034] In Comparative Example 3, the metal soap lubricant was zinc stearate, the antioxidant was antioxidant 300P, the phosphorus-nitrogen flame retardant was melamine orthophosphate, the melt flow rate of the linear low-density polyethylene resin was 2 g / 10 min, and the melt flow rate of the high-density polyethylene resin was 4 g / 10 min.

[0035] The properties of the Class A flame-retardant polyethylene cable materials prepared in Examples 1-4 above are shown in Table 3:

[0036] Table 3

[0037]

[0038] The properties of the Class A flame-retardant polyethylene cable materials prepared in Comparative Examples 1-3 above are shown in Table 4:

[0039] Table 4

[0040]

[0041] As shown in Tables 3 and 4, the Class A flame-retardant polyethylene cable materials prepared in Examples 1-4 all exhibited an environmental stress cracking resistance time exceeding 260 hours; the Class A flame-retardant polyethylene cable materials prepared in Comparative Examples 1-3 had a maximum environmental stress cracking resistance time of 218 hours. Therefore, the Class A flame-retardant polyethylene cable materials prepared by the method of this invention, while ensuring flame-retardant performance, extend the environmental stress cracking resistance time of flame-retardant polyethylene to over 260 hours, resulting in better environmental stress cracking resistance after the flame-retardant polyethylene cable material is formed into the cable sheath.

[0042] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing Class A flame-retardant polyethylene cable material, characterized in that: Includes the following steps: Step 1: Add 100 parts of high-density polyethylene resin with a melt flow rate of 3~8 g / 10min, 35~55 parts of linear low-density polyethylene resin, 5~15 parts of maleic anhydride-grafted vinyl acetate, 3~5 parts of carbon black, 50~60 parts of aluminum hydroxide, 10~30 parts of magnesium hydroxide, 2~8 parts of phosphorus-nitrogen flame retardant, and 3~6 parts of metal soap lubricant to a mixer, and then start mixing until the material temperature reaches 120℃~150℃ to obtain the first mixture. Step 2: Add 0.5-2 parts of antioxidant, 1-5 parts of diisononyl phthalate, 2-5 parts of lauryl acrylate, and 1-3 parts of hyperbranched polyethyleneimine to the first mixture, and mix in an internal mixer at a mixing temperature of 100-110℃ to obtain the second mixture. Step 3: Feed the second mixture into a twin-screw extruder and extrude and granulate it at 160~170℃ to obtain the polyethylene cable material.

2. The method for preparing Class A flame-retardant polyethylene cable material according to claim 1, characterized in that: The metal soap lubricant is calcium stearate or zinc stearate.

3. The method for preparing Class A flame-retardant polyethylene cable material according to claim 1, characterized in that: The antioxidant is one of antioxidant 1010, antioxidant 1076, antioxidant 168, and antioxidant 626.

4. The method for preparing Class A flame-retardant polyethylene cable material according to claim 1, characterized in that: The phosphorus-nitrogen flame retardant is at least one of melamine polyphosphate, melamine pyrophosphate, melamine orthophosphate, ammonium polyphosphate, melamine phosphate salt, di-neopentyl glycol-m-phenylenediamine diphosphate, and melamine phosphate salt.

5. The method for preparing Class A flame-retardant polyethylene cable material according to claim 1, characterized in that: The melt flow rate of the linear low-density polyethylene resin is 0.05~2 g / 10min.

6. The method for preparing Class A flame-retardant polyethylene cable material according to claim 1, characterized in that: The mixing time in step one is 30-60 minutes, and the mixing time in step two is 10-15 minutes.

Images