Thermoplastic polypropylene cable material for heat-resistant 125°C wiring and preparation method thereof

Abstract

The invention discloses a thermoplastic polypropylene cable material for heat-resistant 125°C wiring and a preparation method thereof, comprising polypropylene, styrene elastomer, rubber oil, compatibilizer, inorganic flame retardant, organic flame retardant, antioxidant, metal passivator and lubricant. The cable material formula of the invention uses an antioxidant and a metal passivator to synergistically inhibit aging. Compared with traditional electron beam irradiation materials and irradiation processes, the invention has significantly convenient, fast, economical and efficient production efficiency through the design of materials and processes, and is a thermoplastic cable material that can be recycled and reused.

Description

Technical Field

[0001] The invention belongs to the technical field of wires and cables, and relates to a thermoplastic polypropylene cable material, in particular to a thermoplastic polypropylene cable material for heat-resistant 125°C wiring and a preparation method thereof. Background Art

[0002] Traditional high temperature resistant, low smoke and halogen-free 125℃ wiring materials are mainly made by electron beam irradiation cross-linking process to make polymers achieve bridges between molecular chains with the help of cross-linking agents such as TAIC and TMPTMA, so that thermoplastic materials form a mesh structure and improve the temperature resistance of the materials. Because irradiation requires special equipment, large investment, large land area, and potential harm to the human body, it is not suitable for all manufacturers to use such equipment, so the irradiated wires need to be sent to a special irradiation plant for irradiation, which is time-consuming, labor-intensive, and uneconomical. In addition, traditional irradiated cross-linked wiring wires cannot be melted and processed again after retirement, and can only be incinerated and buried, causing environmental pollution problems. The demand for green and sustainable economic development has prompted the transformation of power cable insulation to low-carbon, environmentally friendly, recycled and recyclable thermoplastic materials. Polypropylene materials have excellent electrical and thermal resistance, and the modified and optimized plasticity is very high, which has great advantages when used in cable materials. At present, there is no public report on thermoplastic polypropylene cable materials for 125℃ heat-resistant wiring wires.

[0003] Chinese patent application number CN202011479230.2 discloses a flame-retardant PVC sheath material for wires that is heat-resistant to 125°C. It can meet the requirement of heat resistance to 125°C, but it uses PVC containing halogens, and the combustion smoke is highly toxic and not environmentally friendly. Chinese patent application number CN201611117345.0 discloses a halogen-free, low-smoke, flame-retardant polyethylene cable material for wiring. Although it has passed the single vertical combustion test and has excellent flame-retardant properties, it cannot meet the requirement of long-term use at 125°C. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a thermoplastic polypropylene cable material for heat-resistant 125°C wiring and a preparation method thereof. The cable material prepared by the present invention is low in smoke and halogen, resistant to high temperature aging, low in cost, does not require radiation cross-linking, and passes the GB / T12666 single wire and cable combustion test.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides a thermoplastic polypropylene cable material for heat-resistant 125°C wiring. The raw materials of the thermoplastic polypropylene cable material for heat-resistant 125°C wiring include 30-50 parts of polypropylene, 15-30 parts of styrene elastomer, 10-20 parts of rubber oil, 10-15 parts of compatibilizer, 80-120 parts of inorganic flame retardant, 5-10 parts of organic flame retardant, 1-3 parts of antioxidant, 1-2 parts of metal passivator and 1-3 parts of lubricant by weight.

[0007] As a preferred embodiment of the present invention, the melting point of the polypropylene is greater than 165° C. and the melt index is 3.0-30.0 g / 10 min.

[0008] As a preferred embodiment of the present invention, the styrene elastomer is selected from at least one of styrene-ethylene-butylene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer and styrene-ethylene-propylene-styrene block copolymer.

[0009] As a preferred embodiment of the present invention, the rubber oil is selected from any one of white oil, paraffin oil and naphthenic oil, or a mixture of at least two of them in any proportion.

[0010] As a preferred embodiment of the present invention, the flame retardant includes an inorganic flame retardant and / or an organic flame retardant, the inorganic flame retardant is any one of magnesium hydroxide, aluminum hydroxide, zinc borate, antimony trioxide, or a mixture of at least two of them in any proportion, and the organic flame retardant is any one of melamine cyanurate, ammonium polyphosphate, diethyl aluminum hypophosphite, or a mixture of at least two of them in any proportion.

[0011] As a preferred embodiment of the present invention, the compatibilizer is polypropylene grafted with maleic anhydride grafted with styrene PP-MAH-PS, wherein the maleic anhydride grafting rate is 1-1.5%;

[0012] In the preparation process of polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, dicumyl peroxide is dissolved in styrene, mixed with polypropylene and maleic anhydride, and then melt-extruded to obtain polypropylene grafted styrene grafted maleic anhydride PP-PS-MAH.

[0013] As a preferred embodiment of the present invention, in the preparation process of polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, the weight ratio of polypropylene, styrene, maleic anhydride and dicumyl peroxide is 80.0-90.0:2.0-5.0:1.0-3.0:0.1-0.8.

[0014] As a preferred embodiment of the present invention, the lubricant is selected from any one of silicone oil, erucamide, stearate, PE wax, or a mixture of at least two of them in any proportion.

[0015] As a preferred embodiment of the present invention, the antioxidant includes at least one of a hindered phenol antioxidant, a thioester antioxidant, and a phosphite antioxidant, and the metal passivator is selected from any one of N-salicylidene-N'-salicylic acid hydrazide, N,N'-diacetyloxalyl dihydrazide and 1,2-bis(2-carboxybenzoyl)hydrazide.

[0016] The present invention also provides a method for preparing the above-mentioned thermoplastic polypropylene cable material for heat-resistant 125°C wiring, the preparation method comprising the following steps:

[0017] 1) stirring the styrene elastomer and the rubber oil at high speed until they are fully mixed, and then adding the remaining components and mixing them uniformly to obtain a mixture;

[0018] 2) Add the mixture into an internal mixer at a temperature of 160°C to 190°C for 20-30 minutes;

[0019] 3) The material obtained in step 2) is fed into a single screw extruder, the speed of the single screw extruder is 200-500 rpm, the extrusion temperature is 160-200°C, and extrusion granulation is performed to obtain a thermoplastic polypropylene cable material for wire wiring with a heat resistance of 125°C.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) The cable material of the present invention can meet the temperature resistance of 125° C. without radiation cross-linking, which simplifies the production process of wire manufacturers and greatly improves the production efficiency of wires.

[0022] 2) The polypropylene resin proposed in the present invention is blended with a styrene elastomer copolymer to form a composite material. Under the compatibilizing effect of the compatibilizer polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, the styrene elastomer copolymer forms an island phase structure, and the polypropylene material plays a role as a continuous phase. The mechanical properties and heat resistance of the material are significantly improved. In addition, due to the rigid benzene ring in the styrene elastomer copolymer, the heat resistance and aging resistance of the material are better improved.

[0023] 3) The cable material formula of the present invention uses an antioxidant and a metal passivator in combination to synergistically inhibit aging.

[0024] 4) Compared with the traditional electron beam irradiation materials and irradiation processes, the present invention has significantly more convenient, quicker, more economical and more efficient production efficiency through the design of materials and processes, and is a thermoplastic cable material that can be recycled and reused. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative work are within the scope of protection of the present invention.

[0026] The invention provides a thermoplastic polypropylene cable material for heat-resistant 125°C wiring. The raw materials of the thermoplastic polypropylene cable material for heat-resistant 125°C wiring include 30-50 parts of polypropylene, 15-30 parts of styrene elastomer, 10-20 parts of rubber oil, 10-15 parts of compatibilizer, 80-120 parts of inorganic flame retardant, 5-10 parts of organic flame retardant, 1-3 parts of antioxidant, 1-2 parts of metal passivator and 1-3 parts of lubricant by weight.

[0027] The main physical and mechanical properties of the thermoplastic polypropylene cable material for heat-resistant 125°C wiring of the present invention are as follows:

[0028] Tensile strength: ≧13Mpa;

[0029] Elongation: ≧200%;

[0030] 158℃ 168 hours aging test:

[0031] Tensile strength change rate: ≦20%;

[0032] Elongation change rate: ≦20%;

[0033] Flame retardancy: passed GB / T 12666 single wire and cable combustion test.

[0034] Passed the 70-year high life cable inspection standard

[0035] Example 1

[0036] The names of the components and weight proportions of the components in the formulation of this embodiment are shown in Table 1:

[0037] Table 1. Raw materials and dosage

[0038]

[0039]

[0040] In the preparation process of the compatibilizer polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, dicumyl peroxide is dissolved in styrene, then mixed with polypropylene and maleic anhydride, and then melt-extruded to obtain polypropylene grafted styrene grafted maleic anhydride PP-PS-MAH; wherein the weight ratio of polypropylene, styrene, maleic anhydride and dicumyl peroxide is 85.0:3.0:1.5:0.3.

[0041] The preparation method of the above-mentioned heat-resistant 125°C thermoplastic polypropylene cable material for wiring harness comprises the following steps: firstly, the components styrene-ethylene-butylene-styrene block copolymer and white oil are stirred at high speed for 10 minutes in a high-speed mixer until they are fully mixed, and then the remaining other components in the raw material formula are added, and mixed evenly to obtain a mixture; then, the mixture is added to an internal mixer, the internal mixer temperature is 185°C, and the internal mixer time is 25 minutes; then, the material is sent to a single-screw extruder, the speed of the single-screw extruder is 200 rpm, the extrusion temperature is 175°C, and extrusion granulation is performed to obtain the heat-resistant 125°C thermoplastic polypropylene cable material for wiring harness.

[0042] The product in Example 1 was subjected to performance testing, and the performance values ​​are shown in Performance Tables 5 and 6.

[0043] Comparative Example 1

[0044] The names of the components and weight proportions of the components in this comparative example are shown in Table 2:

[0045] Table 2. Raw materials and dosage

[0046]

[0047]

[0048] The preparation method of the above cable material is the same as that of Example 1.

[0049] The product in Comparative Example 1 was subjected to performance testing, and the performance values ​​are shown in Table 6.

[0050] Comparative Example 2

[0051] The names of the components and weight proportions of the components in this comparative example are shown in Table 3:

[0052] Table 3. Raw materials and dosage

[0053]

[0054] The preparation method of the above cable material is the same as that of Example 1.

[0055] The product in Comparative Example 2 was subjected to performance testing, and the performance values ​​are shown in Table 6.

[0056] Comparative Example 3

[0057] The names of the components and weight proportions of the components in this comparative example are shown in Table 3:

[0058] Table 4. Raw materials and dosage

[0059]

[0060]

[0061] The preparation method of the above cable material is the same as that of Example 1.

[0062] The product in Comparative Example 3 was subjected to performance testing, and the performance values ​​are shown in Performance Example Table 6.

[0063] Table 5. Main physical properties data of cable material in Example 1

[0064]

[0065] Table 6 Performance test results of Example 1 and Comparative Examples 1-3

[0066]

[0067] It can be seen from Table 6 that:

[0068] 1. It can be seen from Comparative Example 1, Comparative Example 2 and Example 1 that the mechanical and heat resistance properties of the material are significantly improved by introducing the styrene elastomer copolymer. In addition, due to the synergistic effect of polypropylene grafted with maleic anhydride and grafted with styrene PP-MAH-PS, the heat resistance of the material is further improved.

[0069] 2. It can be seen from Comparative Example 3 and Example 1 that the metal passivator and the antioxidant have a synergistic effect and the aging resistance is significantly improved.

[0070] The experimental methods without specific conditions in the examples are usually measured according to national standards. If there is no corresponding national standard, it is carried out according to the general international standards, conventional conditions, or according to the conditions recommended by the manufacturer. Unless otherwise specified, all parts are by weight and all percentages are by weight.

[0071] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. Thermoplastic polypropylene cable material for heat-resistant 125℃ wiring, characterized in that: The raw materials of the thermoplastic polypropylene cable material for heat-resistant 125°C wiring include 30-50 parts of polypropylene, 15-30 parts of styrene elastomer, 10-20 parts of rubber oil, 10-15 parts of compatibilizer, 80-120 parts of inorganic flame retardant, 5-10 parts of organic flame retardant, 1-3 parts of antioxidant, 1-2 parts of metal passivator and 1-3 parts of lubricant by weight.

2. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 1, characterized in that: The polypropylene has a melting point greater than 165° C. and a melt index of 3.0-30.0 g / 10 min.

3. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 1, characterized in that: The styrene elastomer is selected from at least one of styrene-ethylene-butylene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer and styrene-ethylene-propylene-styrene block copolymer.

4. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 1, characterized in that: The rubber oil is selected from any one of white oil, paraffin oil and naphthenic oil, or a mixture of at least two of them in any proportion.

5. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 1, characterized in that: The flame retardant includes an inorganic flame retardant and / or an organic flame retardant. The inorganic flame retardant is any one of magnesium hydroxide, aluminum hydroxide, zinc borate, and antimony trioxide, or a mixture of at least two of them in any proportion. The organic flame retardant is any one of melamine cyanurate, ammonium polyphosphate, and diethylaluminum hypophosphite, or a mixture of at least two of them in any proportion.

6. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 1, characterized in that: The compatibilizer is polypropylene grafted with maleic anhydride grafted with styrene PP-MAH-PS, wherein the maleic anhydride grafting rate is 1-1.5%; In the preparation process of polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, dicumyl peroxide is dissolved in styrene, mixed with polypropylene and maleic anhydride, and then melt-extruded to obtain polypropylene grafted styrene grafted maleic anhydride PP-PS-MAH.

7. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 6, characterized in that: In the preparation process of polypropylene grafted maleic anhydride grafted styrene PP-MAH-PS, the weight ratio of polypropylene, styrene, maleic anhydride and dicumyl peroxide is 80.0-90.0:2.0-5.0:1.0-3.0:0.1-0.

8.

8. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 6, characterized in that: The lubricant is selected from any one of silicone oil, erucamide, stearate, PE wax, or a mixture of at least two of them in any proportion.

9. The thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to claim 6, characterized in that: The antioxidant comprises at least one of hindered phenol antioxidants, thioester antioxidants and phosphite antioxidants, and the metal passivator is selected from any one of N-salicylidene-N'-salicylic acid hydrazide, N,N'-diacetyloxalyl dihydrazide and 1,2-bis(2-carboxybenzoyl)hydrazide.

10. A method for preparing a thermoplastic polypropylene cable material for heat-resistant 125°C wiring according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: 1) stirring the styrene elastomer and rubber oil at high speed until they are fully mixed, then adding the remaining components and mixing them evenly to obtain a mixture; 2) Add the mixture into an internal mixer at a temperature of 160°C to 190°C for 20-30 minutes; 3) The material obtained in step 2) is fed into a single screw extruder, the speed of the single screw extruder is 200-500 rpm, the extrusion temperature is 160-200°C, and extrusion granulation is performed to obtain a thermoplastic polypropylene cable material for wire wiring with a heat resistance of 125°C.

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