Oil-resistant high-temperature-resistant flame-retardant crosslinked polyethylene rubber material, preparation method and cable

Abstract

The invention relates to the technical field of insulating rubber materials, in particular to an oil-resistant high-temperature-resistant flame-retardant cross-linked polyethylene rubber material, a preparation method and a cable, and the oil-resistant high-temperature-resistant flame-retardant cross-linked polyethylene rubber material comprises the following components in parts by weight: 60-100 parts of mixed resin, 30-50 parts of modified resin, 60-80 parts of a flame retardant, 10-15 parts of an antioxidant, 3-8 parts of a lubricant and 2-6 parts of a cross-linking aid, the mixed resin is prepared by mixing an EVA copolymer and POE resin. The oil-resistant high-temperature-resistant flame-retardant cross-linked polyethylene rubber material obtained by the formula and the process disclosed by the invention has the temperature-resistant grade of 150 DEG C, passes a VW-1 combustion test, meets the test condition of 60 DEG C oil-resistant grade cross-linked polyethylene rubber material in UL standard, and fills the blank of 60 DEG C oil-resistant grade cross-linked polyethylene rubber material in UL standard in the market. Through a UL standard 60 DEG C oil-resistant grade test, the temperature-resistant grade of 150 DEG C and the VW-1 combustion performance are met at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of insulating rubber materials, and in particular to an oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material, a preparation method thereof, and a cable. Background Art

[0002] Cross-linked polyethylene is a thermosetting plastic. Currently, XLPE cables have been widely used in power transmission, urban power supply, industrial power supply and other fields. Its development context carries the technological progress and innovation of the power industry. XLPE has excellent electrical properties, excellent heat resistance, and excellent mechanical properties, but one of the shortcomings of XLPE as a cable sheath is that it is not oil-resistant. XLPE materials are prone to swelling, softening, or even rupture when in contact with oil substances for a long time, resulting in a decrease in cable performance or even failure. Therefore, the application of XLPE as a cable sheath is limited in situations where it needs to come into contact with oil substances. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides an oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber material, comprising the following components in parts by weight: 60-100 parts of a mixed resin, 30-50 parts of a modified resin, 60-80 parts of a flame retardant, 10-15 parts of an antioxidant, 3-8 parts of a lubricant, and 2-6 parts of a cross-linking aid. The mixed resin is prepared by mixing an EVA copolymer and a POE resin.

[0004] Preferably, the mass ratio of the EVA copolymer to the POE resin is (2-3):1.

[0005] Preferably, the modified material is one of maleic anhydride grafted polyethylene, chloroprene rubber and fluororubber.

[0006] Preferably, the flame retardant is magnesium hydroxide, decabromodiphenylethane, antimony trioxide or a mixture of the two or more thereof.

[0007] Preferably, the crosslinking aid is trimethylolpropane trimethacrylate.

[0008] Preferably, the lubricant is a silicone lubricant or an ester.

[0009] Preferably, a preparation method for preparing the above-mentioned oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber material comprises the following steps:

[0010] S100, placing the mixed resin, modified resin, flame retardant, antioxidant, cross-linking aid and lubricant into an internal mixer according to the component ratio, with the rotor speed of 30-40rpm / min, the rotor speed ratio v1:v2=1:(1.15-1.19), the upper push bolt pressure of 0.45-0.75Mpa, and when the internal mixing temperature reaches 90°C and 120°C, sweeping the internal mixer once respectively, and the internal mixing is completed when the raw material friction self-heating temperature rises to 140°C;

[0011] S200, conveying the mixture obtained by banburying to a co-rotating meshing twin-screw extruder for extrusion granulation, with a feeding speed of 15-25 rpm / min, the screws rotating in the same direction, a speed of 90-110 rpm / min, an extrusion temperature of 140-145° C., a line speed of 30-40 m / min, pelletizing and air cooling to obtain a primary granulated rubber material;

[0012] S300, subjecting the primary granulated rubber compound to secondary mixing, and when the temperature reaches 120-130°C, conveying the mixture to a twin-screw extruder for extrusion granulation, with an extrusion temperature of 140-145°C, to obtain secondary granulated oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber compound.

[0013] Preferably, in S100, the rotor of the internal mixer is triangular, the rotor speed ratio v1 / v2=1:1.17, the ridges are welded with hard alloy HRC55-62, and the rest is sprayed with 2-3 mm wear-resistant alloy.

[0014] Preferably, a cable is manufactured using the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber obtained by the above preparation method, comprising the following steps: drying the rubber and placing it in an extruder, with a screw speed of 200-300rpm / min and an extrusion line speed of 20-30m / min; the temperature of the feeding section, compression section and metering section is 150-170°C, and an insulating layer is extruded outside the conductor to obtain a finished cable.

[0015] Preferably, the rubber material is dried in an oven at 100°C for 2h and extruded using a single screw extruder with a screw diameter of 65mm, the screw aspect ratio is 1:23-24, the compression ratio is 2.5, and the temperature from the feeding section to the die is 150°C, 160°C, 165°C, 170°C, 170°C, 170°C, and 165°C.

[0016] As can be seen from the above, the application of the rubber compound provided by the present invention can obtain the following beneficial effects: the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber compound obtained by the formula and process of the present invention not only has a temperature resistance grade of 150°C, but also passes the VW-1 combustion test, and meets the test conditions of the UL standard 60°C oil-resistant grade cross-linked polyethylene rubber compound, filling the market gap of the UL standard 60°C oil-resistant grade cross-linked polyethylene rubber compound. It reaches the UL standard 60°C oil resistance grade, and achieves the simultaneous satisfaction of the 150°C temperature resistance grade and VW-1 combustion performance. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1

[0019] In order to solve the above technical problems, the present embodiment provides an oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material, comprising the following components in parts by weight: 60 to 100 parts of a mixed resin, 30 to 50 parts of a modified resin, 60 to 80 parts of a flame retardant, 10 to 15 parts of an antioxidant, 3 to 8 parts of a lubricant, and 2 to 6 parts of a cross-linking aid. The mixed resin is prepared by mixing an EVA copolymer and a POE resin.

[0020] Specifically, the mass ratio of the EVA copolymer to the POE resin is (2-3):1, and preferably, the mass ratio of the EVA copolymer to the POE resin is 2:1.

[0021] Furthermore, the modified material is one of maleic anhydride grafted polyethylene and chloroprene rubber. Among them, maleic anhydride grafted polyethylene has strong polarity, which makes the product have good processability of polyethylene, so that the produced rubber has excellent performance, and can effectively enhance the tolerance of the rubber to non-polar oil. The same is true for chloroprene rubber and fluororubber. Halogens in the molecular structure can increase the polarity of the molecule. Preferably, the modified material is 40 parts of maleic anhydride grafted polyethylene.

[0022] Specifically, the mixed resin is 90 parts, of which 60 parts are EVA resin and 30 parts are POE resin.

[0023] Furthermore, the flame retardant is a mixture of magnesium hydroxide, decabromodiphenylethane, antimony trioxide or more. Preferably, the flame retardant is a mixture of magnesium hydroxide, decabromodiphenylethane, and antimony trioxide, wherein 25 parts of each of magnesium hydroxide, decabromodiphenylethane, and antimony trioxide are used.

[0024] Furthermore, the crosslinking aid is 3 parts, and the crosslinking aid is trimethylolpropane trimethacrylate. The lubricant is a silicone lubricant or ester, and preferably, the lubricant is 4 parts of silicone lubricant. The antioxidant is 10 parts of 1010 antioxidant.

[0025] A preparation method for preparing the above-mentioned oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber material comprises the following steps:

[0026] S100, placing the mixed resin, modified resin, flame retardant, antioxidant, cross-linking aid and lubricant into an internal mixer according to the component ratio, the rotor speed of the internal mixer is 30-40 rpm / min, the rotor speed ratio is v1:v2=1:(1.15-1.19), the upper push bolt pressure is 0.45-0.75 MPa, when the internal mixer temperature reaches 90°C and 120°C, the internal mixer is swept once respectively, and the internal mixer is completed when the raw material friction self-heating temperature rises to 140°C;

[0027] In step S100, the rotor of the internal mixer is triangular, the rotor speed ratio v1:v2=1:1.17, the rotor ridges are clad with hard alloy HRC55-62, and the rest is sprayed with 2-3mm wear-resistant alloy. Preferably, the rotor ridges are clad with hard alloy HRC62, the rest of the rotor is sprayed with 3mm wear-resistant alloy, and the upper push bolt pressure of the internal mixer is 0.75Mpa. By designing the rotor shape and speed ratio of the internal mixer, the internal mixing effect of the material is improved, thereby improving various aspects of the performance of the finished rubber compound.

[0028] S200, conveying the mixture obtained by banburying to a co-rotating meshing twin-screw extruder for extrusion granulation, with a feeding speed of 15-25 rpm / min, the screws rotating in the same direction, a speed of 90-110 rpm / min, an extrusion temperature of 140-145° C., a line speed of 30-40 m / min, pelletizing and air cooling to obtain a primary granulated rubber material;

[0029] The uniformly mixed mixture obtained in step S100 is conveyed to a co-rotating meshing twin-screw extruder for extrusion granulation, with a feeding speed of 20 rpm / min, the screws rotating in the same direction, a speed of 100 rpm / min, an extrusion temperature of 140° C., a line speed of 30 m / min, and pelletized and air-cooled to obtain a primary granulated rubber material;

[0030] S300, the rubber compound obtained in step S200 is put into a mixer for secondary mixing. When the temperature reaches 130°C, the mixture is transported to a twin-screw extruder for extrusion granulation. The feeding speed is 30rpm / min, the screws rotate in the same direction, the speed is 110rpm / min, the extrusion temperature is 145°C, and the line speed is 40m / min, so as to obtain the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber compound for secondary granulation. After the first granulation, the raw materials such as EVA resin, POE resin, maleic anhydride grafted polyethylene are preliminarily mixed and melted. The processing parameters of the twin screw during the secondary granulation are higher than those during the primary granulation. After the secondary twin-screw extrusion granulation, a polyethylene rubber compound with a more uniform mixed phase is obtained, which ensures the oil resistance, high temperature resistance, flame retardancy and other properties.

[0031] Preferably, a cable is manufactured using the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber obtained by the above preparation method, comprising the following steps: drying the rubber and placing it in an extruder, with a screw speed of 200 to 300 rpm / min and an extrusion line speed of 20 to 30 m / min; the temperature of the feeding section, compression section and metering section is 150 to 170°C, and an insulating layer is extruded outside the conductor to obtain a finished cable.

[0032] Furthermore, before being placed in the extruder, the rubber compound was dried in an oven at 100°C for 2 h, and extruded using a single screw extruder with a screw diameter of 65 mm, the screw aspect ratio of 1:(23-24), the compression ratio of 2.5, and the temperatures from the feeding section to the die were 150°C, 160°C, 165°C, 170°C, 170°C, 170°C, and 165°C.

[0033] After the oil-resistant, high-temperature, flame-retardant cross-linked polyethylene rubber compound is obtained by the above preparation method, the obtained oil-resistant, high-temperature, flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder, achieving both UL 60°C oil resistance grade and 150°C temperature resistance grade, and meeting the flame retardant VW-1 grade test.

[0034] Example 2

[0035] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of POE resin, 40 parts of fluororesin, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0036] The steps of the preparation method are the same as those of Example 1, and the obtained oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder.

[0037] Example 3

[0038] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of POE resin, 40 parts of chloroprene rubber, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0039] The steps of the preparation method are the same as those of Example 1, and the obtained oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder.

[0040] Example 4

[0041] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of EPDM resin, 40 parts of maleic anhydride grafted polyethylene, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0042] The steps of the preparation method are the same as those of Example 1, and the obtained oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder.

[0043] Example 5

[0044] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of EPDM resin, 40 parts of fluororesin, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane, and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0045] The steps of the preparation method are the same as those of Example 1, and the obtained oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder.

[0046] Example 6

[0047] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of EPDM resin, 40 parts of chloroprene rubber, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0048] The steps of the preparation method are the same as those of Example 1, and the obtained oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene cable pellets are extruded into cable wires through an extruder.

[0049] Example 7

[0050] The components of the oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material of this embodiment are as follows: 60 parts of EVA resin, 30 parts of EPDM resin, 40 parts of maleic anhydride grafted polyethylene, 25 parts each of flame retardants magnesium hydroxide, decabromodiphenylethane and antimony trioxide, 10 parts of 1010 antioxidant, 4 parts of silicone lubricant, and 3 parts of cross-linking aid.

[0051] In the method for preparing the oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber, unlike Example 1, this embodiment removes step S300, that is, the secondary granulation process is omitted, and the rubber obtained by the primary granulation is dried and put into an extruder, and extruded outside the conductor to form an insulating layer to obtain a finished cable.

[0052]

[0053]

[0054] Table 1

[0055]

[0056] Table 2

[0057] Table 1 above shows the raw material formula of the oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber materials of Examples 1 to 7.

[0058] As shown in Table 2 above, the performance test results of cables made from the oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber materials of Examples 1 to 7 are shown.

[0059] From the comparison of the test results of Example 1, Example 2 and Example 3 in Table 2 above, it can be seen that maleic anhydride grafted polyethylene, fluororesin and chloroprene rubber can all modify the rubber and pass the UL 60°C oil resistance test. However, by comparing the data before aging, it can be seen that although fluororesin can improve the overall tensile strength of the rubber, it also has a greater impact on the elongation of the rubber, and the margin of qualified data is not large. Therefore, the use of fluororesin will affect the elongation performance of the rubber. In Example 1, maleic anhydride grafted polyethylene is used as the modified material, so that the wire achieves good oil resistance and the best elongation performance.

[0060] By comparing the results of Examples 1, 2, and 3 with those of Examples 4, 5, and 6, it can be seen that after replacing the POE resin in the mixed resin with the EPDM resin, the overall strength of the rubber material is increased, but the elongation is greatly reduced. In Example 5, after the fluororesin and EPDM resin are used in combination, the elongation before aging is unqualified, and the aging test and oil resistance test performance are poor. Therefore, the EVA resin in Example 1 is used in combination with the POE resin and the maleic anhydride grafted polyethylene. While ensuring that the tensile strength and aging test are qualified, the oil resistance of the wire obtained in Example 1 is the best.

[0061] By comparing the results of Examples 1 and 7, it can be seen that Example 7 only adopts one granulation process, and its performance in all aspects is inferior to that of Example 1. It can be seen that the use of a secondary granulation process can improve the various properties of the rubber compound to a certain extent, thereby improving the wire strength, aging performance and oil resistance.

[0062] According to the above comparison, it can be seen that Example 1 has the largest data margin before aging, after aging and in the oil resistance test. Taking all factors into consideration, Example 1 is the optimal formula and process. The oil-resistant, high-temperature resistant, flame-retardant cross-linked polyethylene rubber obtained by the formula and process of the present invention can reach the UL standard 60°C oil resistance grade, and achieve the 150°C temperature resistance grade and VW-1 combustion performance at the same time.

[0063] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. An oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material, characterized in that: The invention comprises the following components in parts by weight: 60-100 parts of mixed resin, 30-50 parts of modified resin, 60-80 parts of flame retardant, 10-15 parts of antioxidant, 3-8 parts of lubricant and 2-6 parts of crosslinking auxiliary agent. The mixed resin is prepared by mixing EVA copolymer and POE resin.

2. The oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material according to claim 1, characterized in that: The mass ratio of the EVA copolymer to the POE resin is (2-3):

1.

3. The oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material according to claim 1, characterized in that: The modified material is one of maleic anhydride grafted polyethylene, chloroprene rubber and fluororubber.

4. The oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material according to claim 1, characterized in that: The flame retardant is one or a mixture of magnesium hydroxide, decabromodiphenylethane and antimony trioxide.

5. The oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material according to claim 1, characterized in that: The crosslinking aid is trimethylolpropane trimethacrylate.

6. The oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber material according to claim 1, characterized in that: The lubricant is a silicone lubricant or an ester.

7. A preparation method, characterized in that: The method for preparing the oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber material according to any one of claims 1 to 6 comprises the following steps: S100, placing the mixed resin, modified resin, flame retardant, antioxidant, cross-linking aid and lubricant into an internal mixer according to the component ratio, the rotor speed of the internal mixer is 30-40 rpm / min, the rotor speed ratio v1:v2=1:(1.15-1.19), the upper push bolt pressure is 0.45-0.75 MPa, when the internal mixer temperature reaches 90°C and 120°C, the internal mixer is swept once respectively, and the internal mixer is completed when the raw material friction self-heating temperature rises to 140°C; S200, conveying the mixture obtained by banburying to a co-rotating meshing twin-screw extruder for extrusion granulation, with a feeding speed of 15-25 rpm / min, the twin screws rotating in the same direction, a rotation speed of 90-110 rpm / min, an extrusion temperature of 140-145° C., a line speed of 30-40 m / min, and pelletizing and air cooling to obtain a primary granulated rubber material; S300, subjecting the rubber compound granulated once to secondary mixing, and when the temperature reaches 120-130°C, conveying the mixture to a twin-screw extruder for extrusion granulation, with the extrusion temperature at 140-145°C, to obtain secondary granulated oil-resistant, high-temperature-resistant, flame-retardant cross-linked polyethylene rubber compound.

8. The preparation method according to claim 7, characterized in that: In S100, the rotor of the internal mixer is triangular in shape, with a rotor speed ratio of v1:v2=1:1.

17. The rotor's ridges are welded with hard alloy with a hardness of HRC55-62, and the rest is sprayed with 2-3 mm wear-resistant alloy.

9. A cable, characterized in that: The oil-resistant, high-temperature-resistant and flame-retardant cross-linked polyethylene rubber compound prepared by the preparation method according to any one of claims 7 to 8 is manufactured, comprising the following steps: after drying the rubber compound, placing it in an extruder, with a screw speed of 200 to 300 rpm / min and an extrusion line speed of 20 to 30 m / min; the temperature of the feeding section, the compression section and the metering section is 150 to 170°C, and an insulating layer is extruded outside the conductor to obtain a finished cable.

10. The cable according to claim 9, characterized in that: The rubber compound was dried in an oven at 100°C for 2 h and extruded using a single screw extruder with a screw diameter of 65 mm. The screw aspect ratio was 1:(23-24), the compression ratio was 2.5, and the temperatures from the feeding section to the die were 150°C, 160°C, 165°C, 170°C, 170°C, 170°C, and 165°C.

Images