A high-flexibility X-ETFE insulating material and preparation method thereof

Abstract

The invention discloses a highly flexible X-ETFE insulating material and a preparation method thereof, wherein the insulating material is prepared from the following raw materials in parts by weight: 100 parts of ETFE resin, 2-10 parts of sensitizer, 5-15 parts of acid absorber, 1-10 parts of flame retardant, 0.2-1 parts of antioxidant, 0.3-3 parts of lubricant, and 15-30 parts of THV resin mixture. The invention utilizes the high softness, high compatibility, and high sensitivity to electron beam irradiation crosslinking of THV resin to modify the rigid ETFE material, and the prepared flexible X-ETFE insulating material meets the standard SAE AS4373E-2012. The wire prepared by the highly flexible X-ETFE insulating material can solve the problem that the traditional rigid X-ETFE wire is difficult to layout and use in a small space, and broaden the application of X-ETFE wire in the fields of aerospace, military equipment, and civilian equipment.

Description

Technical Field

[0001] The invention relates to the technical field of cable materials, and in particular to a high-flexibility X-ETFE insulating material and a preparation method thereof. Background Art

[0002] Cross-linked ethylene-tetrafluoroethylene (X-ETFE) has high hardness and a bending modulus of more than 800 MPa, which makes it very difficult to lay out wires made of this material in a small space, making it very inconvenient to use in practice. Flexible X-ETFE insulation materials are rarely studied in China, and there is no corresponding standard. The standard SAE AS4373E-2012 stipulates the relevant technical indicators of flexible X-ETFE insulation materials for aerospace use, including tensile strength ≥24 MPa, elongation at break ≥75%, and bending modulus ≤345 MPa. At present, there are few research patents or papers on flexible X-ETFE insulation materials in China. The existing method for modifying the flexibility of X-ETFE is to toughen and modify FKM (fluororubber). The flexible X-ETFE insulation materials prepared by this method can indeed meet SAE AS4373E-2012, but have the following shortcomings: ① The processing of FKM modified materials is complicated, and the raw rubber needs to be mixed with various additives and then connected to screw granulation and air-cooled hot-cut particles, which requires large equipment investment. ②The compatibility of FKM and ETFE is slightly poor, resulting in a significant decrease in the mechanical properties of the material. ③The amount of carbon black added in the FKM formula is large, which has great pollution to the equipment and the environment. Summary of the invention

[0003] In order to solve the deficiencies of the prior art, the present invention provides a highly flexible X-ETFE insulating material and a preparation method thereof, wherein tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (abbreviated as THV) is used to modify X-ETFE, and the flexibility and mechanical properties thereof can meet the standard SAE AS4373E-2012, and the THV resin is easy to use, and only needs to be mixed in an ordinary high-mixer, and then put into a twin-screw granulator for melt granulation, without the need for additional equipment investment, and is environmentally friendly and pollution-free. In addition, THV and ETFE have good compatibility, and compared with FKM, the mechanical properties of the THV-modified X-ETFE insulating material under the same addition amount are better than those of the FKM-modified X-ETFE insulating material.

[0004] The present invention adopts the following technical solution:

[0005] A highly flexible X-ETFE insulating material is prepared from the following raw materials in parts by weight:

[0006] ETFE resin 100 parts;

[0007] 2-10 parts of sensitizer;

[0008] 5-15 parts of acid absorbent;

[0009] Flame retardant 1-10 parts;

[0010] Antioxidant 0.2-1 part;

[0011] Lubricant 0.3-3 parts;

[0012] 15-30 parts of THV resin mixture;

[0013] The THV resin mixture is a mixture of THV resins with various flexural moduli.

[0014] The ETFE resin has a melt index of 10 g / 10 min-35 g / 10 min measured at 297° C. / 5 kg, and a melting temperature of 250° C.-265° C.

[0015] The sensitizer is one or a combination of triallyl isocyanurate (abbreviated as TAIC), trimethylallyl isocyanate (abbreviated as TMAIC), trimethylolpropane trimethacrylate (abbreviated as TMPTMA).

[0016] The acid absorbent is one or a combination of zinc oxide, magnesium oxide, calcium hydroxide and calcium carbonate.

[0017] The flame retardant is one or a combination of antimony trioxide, antimony pentoxide, and anhydrous zinc borate.

[0018] The antioxidant is one or a combination of several proportions of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester (abbreviation: 1010), 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine (abbreviation: 1024), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (abbreviation: 1076), and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid (abbreviation: 3114).

[0019] The lubricant is a compound mixture of ethylene bis stearamide and carrier-free silicone, with a mass ratio of 3:1.

[0020] The THV resin mixture consists of THV resin A, THV resin B, and THV resin C. The melt index of each THV resin measured at 265°C / 5kg is 8g / 10min-25g / 10min, the melting point is 110°C-230°C, and the bending modulus is 60MPa-550MPa. The bending modulus of THV resin A is 65MPa, the bending modulus of THV resin B is 210MPa, and the bending modulus of THV resin C is 510MPa. The mass ratio of each THV resin in the THV resin mixture is THV resin A:THV resin B:THV resin C=2.5:1:0.5.

[0021] A method for preparing a highly flexible X-ETFE insulating material comprises the following steps:

[0022] S1. Weigh all the raw materials except the sensitizer according to the formula, put them into a 50L high-speed mixer for stirring, and then put the preliminarily mixed materials into a parallel co-rotating twin-screw feeding hopper. The molten materials are water-cooled and stretched in a water tank, and the surface water is removed by cyclone separation and pelletized to obtain material mixed particles;

[0023] S2. The material mixed particles and sensitizer prepared in S1 are weighed according to the formula, put into a 50L high-speed mixer for stirring, and then the preliminarily evenly mixed materials are put into the parallel co-rotating twin-screw feeding hopper again. The molten material is water-cooled in a water tank and drawn into strips. The surface water is removed by cyclone separation and pelletized. It is then dried at 80℃±10℃ for 4h to obtain a highly flexible X-ETFE insulating material.

[0024] In step S1, the speed of the high-speed mixer is set to 80rpm-100rpm, the stirring time is 5min-10min; the diameter of the twin screw is 30mm, the aspect ratio is 36:1, the screw speed is 150rpm-250rpm, the ratio of the screw speed to the feed speed is 10:1, and the extrusion temperature is 250℃-300℃.

[0025] In step S2, the speed of the high-speed mixer is set to 110rpm-130rpm, the stirring time is 3min-6min; the diameter of the twin screw is 30mm, the aspect ratio is 36:1, the screw speed is 100rpm-200rpm, the ratio of the screw speed to the feed speed is 10:1, and the extrusion temperature is 250℃-280℃.

[0026] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0027] A. The present invention achieves high flexibility of the material by using tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV) to modify X-ETFE, making it easy to lay out X-ETFE insulation materials in a small space, greatly improving the convenience of actual use. This flexibility fully meets the technical indicators of standard SAE AS4373E-2012, including tensile strength, elongation at break and flexural modulus.

[0028] B. Compared with the traditional FKM toughening modification method, the THV modification in the present invention not only has a simpler processing process, but also only requires mixing the materials in an ordinary high-speed mixer and then putting them into a twin-screw granulator for melt granulation, without the need for additional equipment investment, thereby reducing production costs.

[0029] C. Due to the good compatibility between THV and ETFE, compared with FKM modification, THV-modified X-ETFE insulation material with the same addition amount shows better mechanical properties, including tensile strength, elongation at break, etc., ensuring the stability and reliability of the material in practical applications.

[0030] D. In the preparation process of the present invention, the THV modification method does not need to use additives that may cause environmental pollution (such as carbon black in FKM modification), which embodies the concept of green production and is more friendly to equipment and the environment.

[0031] E. The present invention utilizes the high softness, high compatibility and high sensitivity to electron beam irradiation cross-linking of THV resin to modify the hard ETFE material. The wires prepared from the high-flexibility X-ETFE insulating material can solve the problem that the traditional hard X-ETFE wires are difficult to lay out and use in a small space, and broaden the application of X-ETFE wires in the fields of aerospace, military equipment, civilian equipment, etc., which is of great significance. DETAILED DESCRIPTION

[0032] The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Instead, these embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the concept of the present invention to those skilled in the art. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0033] In the following embodiments, the THV mixture used is composed of THV resin A, THV resin B, and THV resin C. The melt index of each THV resin measured at 265°C / 5kg is 8g / 10min~25g / 10min, the melting point is 110°C~230°C, the bending modulus of THV resin A is 65MPa, the bending modulus of THV resin B is 210MPa, and the bending modulus of THV resin C is 510MPa. The mass ratio of each THV resin in the THV resin mixture is THV resin A: THV resin B: THV resin C = 2.5: 1: 0.5. Preparation of standard samples: The modified X-ETFE insulating material is evenly spread in a mold frame with a size of 120mm×100mm and a thickness of 1mm. A polytetrafluoroethylene film and a steel plate are placed on top and bottom. The whole is placed on the heating layer of the flat vulcanizer, heated to 285℃±5℃, kept warm for 5min~10min without pressure, then applied with a pressure of 1.5MPa and maintained for 1min~1.5min, then continued to apply a pressure of 3MPa~5MPa and maintained for 2min~3min, and then cold pressed. The irradiation parameters of the samples in all the following embodiments are unified as follows: irradiation energy 1.5MeV, irradiation dose 13.5Mrad. Example 1

[0034] This embodiment provides a flexible X-ETFE insulating material, which is as follows:

[0035]

[0036] The preparation method is as follows:

[0037] S1. Weigh all raw materials except sensitizer according to the formula, put them into a 50L high-speed mixer for stirring, set the speed to 80rpm-100rpm, and stir for 5min-10min; then put the preliminarily mixed materials into a parallel co-rotating twin-screw feeding hopper, the twin screws have a diameter of 30mm, an aspect ratio of 36:1, a screw speed of 150rpm-250rpm, a screw speed to feed speed ratio of 10:1, an extrusion temperature of 250℃-300℃, and the molten material is water-cooled in a water tank to form strips, and the surface water is removed by cyclone separation and pelletized to obtain material mixed particles;

[0038] S2. The material mixed particles and sensitizer prepared in S1 are weighed according to the formula, and put into a 50L high-speed mixer for stirring. The speed is set to 110rpm-130rpm, and the stirring time is 3min-6min. Then the preliminarily mixed material is put into the parallel co-rotating twin-screw feeding hopper again. The twin screw has a diameter of 30mm, an aspect ratio of 36:1, a screw speed of 100rpm-200rpm, a screw speed and a feed speed ratio of 10:1, and an extrusion temperature of 250℃-280℃. The molten material is water-cooled in a water tank and drawn into strips. The surface water is removed by cyclone separation and pelletized. It is then dried at 80℃±10℃ for 4h to obtain a highly flexible X-ETFE insulating material. Example 2

[0039] This embodiment provides a flexible X-ETFE insulating material, which is as follows:

[0040]

[0041] The preparation method of this embodiment is the same as that of embodiment 1. Example 3

[0042] This embodiment provides a flexible X-ETFE insulating material, which is as follows:

[0043]

[0044] The preparation method of this embodiment is the same as that of embodiment 1. In this embodiment, no acid absorber is used, and the acid absorber does not affect the tensile strength, elongation at break and flexural modulus of the insulating material. Example 4

[0045] This embodiment provides a flexible X-ETFE insulating material, which is as follows:

[0046]

[0047] The preparation method of this embodiment is the same as that of embodiment 1. Comparative Example

[0048] This comparative example provides a kind of X-ETFE edge material, which is as follows:

[0049]

[0050] The preparation method of this embodiment is the same as that of embodiment 1.

[0051] By comparing the comparative example with Example 1, it can be found that a lower addition amount of THV can make X-ETFE reach a low flexural modulus of 278 MPa. At the same time, other properties of Example 1 are better than those of the comparative example, and the fluidity and processability are better.

[0052] The present invention utilizes the high softness, high compatibility and high sensitivity to electron beam irradiation crosslinking of THV resin to modify the hard ETFE material, and the prepared flexible X-ETFE insulating material meets the standard SAE AS4373E-2012. The wire prepared by using the highly flexible X-ETFE insulating material can solve the problem that the traditional hard X-ETFE wire is difficult to arrange and use in a small space, and broadens the application of X-ETFE wire in the fields of aerospace, military equipment, civilian equipment, etc., which is of great significance.

[0053] Anything not described in the present invention is applicable to the prior art.

[0054] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A highly flexible X-ETFE insulating material, characterized in that: It is prepared from the following raw materials in parts by weight: ETFE resin 100 parts; 2-10 parts of sensitizer; 5-15 parts of acid absorbent; Flame retardant 1-10 parts; Antioxidant 0.2-1 part; Lubricant 0.3-3 parts; 15-30 parts of THV resin mixture; The THV resin mixture is a mixture of THV resins with various bending moduli; The ETFE resin has a melt index of 10 g / 10 min-35 g / 10 min measured at 297° C. / 5 kg, and a melting temperature of 250° C.-265° C.; The THV resin mixture consists of THV resin A, THV resin B, and THV resin C. The melt index of each THV resin measured at 265°C / 5kg is 8g / 10min-25g / 10min, the melting point is 110°C-230°C, and the bending modulus is 60MPa-550MPa. The bending modulus of THV resin A is 65MPa, the bending modulus of THV resin B is 210MPa, and the bending modulus of THV resin C is 510MPa. The mass ratio of each THV resin in the THV resin mixture is THV resin A:THV resin B:THV resin C=2.5:1:0.

5.

2. The highly flexible X-ETFE insulating material according to claim 1, characterized in that: The sensitizer is one or a combination of triallyl isocyanurate, trimethallyl isocyanate, trimethylolpropane trimethacrylate.

3. The highly flexible X-ETFE insulating material according to claim 1, characterized in that: The acid absorbent is one or a combination of zinc oxide, magnesium oxide, calcium hydroxide and calcium carbonate.

4. The highly flexible X-ETFE insulating material according to claim 1, characterized in that: The flame retardant is one or a combination of antimony trioxide, antimony pentoxide, and anhydrous zinc borate; The antioxidant is one or a combination of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid.

5. The highly flexible X-ETFE insulating material according to claim 1, characterized in that: The lubricant is a compound mixture of ethylene bis stearamide and carrier-free silicone, with a mass ratio of 3:

1.

6. A method for preparing the highly flexible X-ETFE insulating material according to any one of claims 1 to 5, characterized in that: The steps include: S1. Weigh all the raw materials except the sensitizer according to the formula, put them into a high-speed mixer for stirring, and then put the preliminarily mixed materials into a parallel co-rotating twin-screw feeding hopper. The molten materials are water-cooled in a water tank and pulled into strips. The surface water is removed by cyclone separation and pelletized to obtain material mixed particles. S2. The material mixed particles and sensitizer prepared in S1 are weighed according to the formula, put into a high-speed mixer for stirring, and then the preliminarily evenly mixed materials are put into the parallel co-rotating twin-screw feeding hopper again. The molten material is water-cooled in a water tank and drawn into strips. The surface water is removed by cyclone separation and pelletized. It is then dried at 80℃±10℃ for 4h to obtain a highly flexible X-ETFE insulating material.

7. The preparation method according to claim 6, characterized in that: In step S1, the speed of the high-speed mixer is set to 80rpm-100rpm, the stirring time is 5min-10min; the diameter of the twin screw is 30mm, the aspect ratio is 36:1, the screw speed is 150rpm-250rpm, the ratio of the screw speed to the feed speed is 10:1, and the extrusion temperature is 250℃-300℃.

8. The preparation method according to claim 6, characterized in that: In step S2, the speed of the high-speed mixer is set to 110rpm-130rpm, the stirring time is 3min-6min; the diameter of the twin screw is 30mm, the aspect ratio is 36:1, the screw speed is 100rpm-200rpm, the ratio of the screw speed to the feed speed is 10:1, and the extrusion temperature is 250℃-280℃.

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