阅读说明：本技术 防水耐热组合物、防水耐热绝缘结构、防水耐热电线及其应用 (Waterproof heat-resistant composition, waterproof heat-resistant insulation structure, waterproof heat-resistant electric wire and application thereof ) 是由 贺超武 柯志欣 取立群 陈帅雨 于 2021-07-29 设计创作，主要内容包括：本申请提供了一种防水耐热组合物、防水耐热绝缘结构、防水耐热电线及其应用,其中防水耐热组合物以重量百分比计,包含以下组分：聚酰胺接枝聚合物80.0-95.0％；阻燃剂0.1-20.0％；所述聚酰胺接枝聚合物中,聚酰胺的熔点大于或等于200℃。本申请防水耐热组合物制得的防水耐热电线,能够适应长期温度高的工作环境,还具有优良的机械强度、耐热性、耐水解性、化学稳定性的优点。(The application provides a waterproof and heat-resistant composition, a waterproof and heat-resistant insulation structure, a waterproof and heat-resistant electric wire and application thereof, wherein the waterproof and heat-resistant composition comprises the following components in percentage by weight: 80.0-95.0% of polyamide graft polymer; 0.1 to 20.0 percent of flame retardant; in the polyamide graft polymer, the melting point of polyamide is greater than or equal to 200 ℃. The waterproof heat-resistant wire prepared from the waterproof heat-resistant composition can adapt to a working environment with high long-term temperature, and has the advantages of excellent mechanical strength, heat resistance, hydrolysis resistance and chemical stability.)

1. A waterproof heat-resistant composition characterized by: comprises the following components in percentage by weight:

80.0-95.0% of polyamide graft polymer;

0.1 to 20.0 percent of flame retardant;

in the polyamide graft polymer, the melting point of polyamide is greater than or equal to 200 ℃.

2. The waterproof heat-resistant composition according to claim 1, wherein the polyamide-grafted polymer is a polyamide-grafted polyolefin; in the polyamide graft polymer, the polyamide is selected from PA6, PA66 or PA 610.

3. The waterproof heat-resistant composition according to claim 1, wherein the flame retardant is one or more of a bromine-based flame retardant, an antimony-based flame retardant and a zinc-based flame retardant.

4. The waterproof and heat-resistant composition according to claim 1, further comprising one or more of the following components in weight percent:

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 18.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

5. A waterproof heat-resistant insulation structure is characterized in that: is produced by using the waterproof and heat-resistant composition as claimed in any one of claims 1 to 4.

6. A waterproof heat-resistant electric wire characterized in that: is produced by using the waterproof and heat-resistant composition as claimed in any one of claims 1 to 4.

7. A waterproof heat-resistant electric wire characterized in that: the waterproof and heat-resistant electric wire comprises an inner insulating layer and an outer insulating layer, the outer insulating layer being made of the waterproof and heat-resistant composition according to any one of claims 1 to 4.

8. The waterproof heat-resistant electric wire according to claim 7, wherein the insulating inner layer is formed of an insulating heat-resistant composition;

the insulating and heat-resistant composition comprises a polyolefin resin selected from one or more of homopolymers and copolymers of polyethylene, ethylene/alpha-olefin copolymers, copolymers of ethylene with an unsaturated carboxylic acid, crosslinkable polyolefins, and ethylene-propylene-diene rubber;

the weight percentage of the polyolefin resin in the insulating heat-resistant composition is 50.0-95.0%.

9. The waterproof heat-resistant electric wire according to claim 8, wherein the insulating heat-resistant composition further comprises one or more of the following components in percentage by weight:

0.1 to 50.0 percent of flame retardant;

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 40.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

10. Use of the waterproof and heat-resistant electric wire according to claim 7 in the field of rail transit.

[ technical field ] A method for producing a semiconductor device

The application relates to the technical field of wires and cables, in particular to a waterproof and heat-resistant composition, a waterproof and heat-resistant insulation structure, a waterproof and heat-resistant wire and application thereof.

[ background of the invention ]

With the development of wire and cable technology, the requirements for conventional wires are becoming more stringent, and in addition to the conventional properties, the conventional wires are often required to have some properties capable of adapting to the specific application environment.

For the rail transit vehicle wire, along with the continuous expansion of rail transit construction, the running speed of vehicles is faster and faster, and the safety requirement is higher and higher. Due to the difference of rail transit safety regulations, vehicle equipment and operating environment of various countries, the adopted standard specifications of electric wires are different. The european union standards EN 50306.1 and.2 specify: according to the different insulating materials, the rated voltage of the wire is 300V, the long-term working temperature is 90 ℃ or 105 ℃, the short-circuit temperature is 160 ℃, the short-circuit temperature lasts 5s, and the section of the conductor is 0.5-2.5mm². North American railroad Association Standard AAR RP-585 specifies: the rated voltage of the wire is 600V, the rated temperature is-55-125 deg.C, the long-term working temperature is 110 deg.C, the overload temperature is 130 deg.C, the short-circuit temperature is 250 deg.C, the short-circuit temperature lasts 5s, and the cross section of the conductor is 0.38-4.74mm²。

In other words, the rail transit vehicle electric wire is required to have good mechanical characteristics in a high temperature environment. Meanwhile, since the rail transit vehicle wire is exposed to water and oil for a long time, it is also required to have long-term water resistance and oil resistance, and in addition, it is required to have high flame retardancy.

Therefore, in order to adapt to the rail transit technology which is developed at a high speed, it is necessary to provide an electric wire which is suitable for the rail transit field and has waterproof, heat-resistant and flame-retardant properties.

[ summary of the invention ]

The purpose of the application is to provide a waterproof and heat-resistant composition with excellent mechanical strength, heat-resistant temperature, hydrolysis resistance and chemical stability, a waterproof and heat-resistant insulation structure and a waterproof and heat-resistant electric wire, and application of the waterproof and heat-resistant electric wire in the field of rail transit.

In order to achieve the purpose, the technical scheme is as follows:

a waterproof and heat-resistant composition comprises the following components in percentage by weight:

80.0-95.0% of polyamide graft polymer;

0.1 to 20.0 percent of flame retardant;

in the polyamide graft polymer, the melting point of polyamide is greater than or equal to 200 ℃.

Preferably, the polyamide-grafted polymer is a polyamide-grafted polyolefin; in the polyamide graft polymer, the polyamide is selected from PA6, PA66 or PA 610.

Preferably, the flame retardant is one or more of a brominated flame retardant, an antimony flame retardant and a zinc flame retardant.

Preferably, the paint also comprises one or more of the following components in percentage by weight:

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 18.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

The application also provides a waterproof heat-resistant insulating structure which is prepared by adopting the waterproof heat-resistant composition.

The application also provides a waterproof and heat-resistant electric wire which is prepared by adopting the waterproof and heat-resistant composition.

The application also provides a waterproof and heat-resistant electric wire, which comprises an inner insulating layer and an outer insulating layer, wherein the outer insulating layer is prepared from the waterproof and heat-resistant composition.

Preferably, the insulating inner layer adopts an insulating heat-resistant composition; the insulating and heat-resistant composition comprises a polyolefin resin selected from one or more of homopolymers and copolymers of polyethylene, ethylene/alpha-olefin copolymers, copolymers of ethylene with an unsaturated carboxylic acid, crosslinkable polyolefins, and ethylene-propylene-diene rubber;

preferably, the polyolefin resin in the insulating heat-resistant composition is 50.0 to 95.0% by weight.

Preferably, the insulating and heat-resistant composition further comprises one or more of the following components in percentage by weight:

0.1 to 50.0 percent of flame retardant;

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 40.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

The application also provides the application of the waterproof heat-resistant electric wire in the field of rail transit transportation.

Compared with the prior art, the method has the following advantages:

first, the waterproof and heat-resistant composition of the present application employs a polyamide graft polymer, which is not only good in electrical or mechanical strength, etc., but also, more importantly, greatly increased in hydrolysis resistance, as compared to conventional polyamides, making it particularly suitable for use in the manufacture of electric wires in the field of rail transit.

Second, in the waterproof and heat-resistant composition of the present application, a high-melting polyamide having a melting point of not less than 200 ℃ is used as the polyamide in the polyamide graft polymer. The adoption of the high-melting-point polyamide ensures that the waterproof heat-resistant composition has the advantages of excellent mechanical strength, heat resistance, hydrolysis resistance and chemical stability, and is particularly suitable for manufacturing electric wires in the field of rail transit.

Thirdly, the weight percentage of the polyamide graft polymer in the waterproof and heat-resistant composition is not less than 80%, so that the high mechanical strength, heat resistance, hydrolysis resistance and chemical stability of the waterproof and heat-resistant composition are ensured.

Fourthly, the waterproof heat-resistant wire can adapt to a working environment with high long-term temperature, wherein the insulating inner layer can maintain the working temperature of 105-150 ℃ for a long time, and the insulating outer layer can maintain the working temperature of 200 ℃ for a long time. Meanwhile, the waterproof heat-resistant wire also has excellent long-term water resistance and oil resistance, and has the advantages of chemical corrosion resistance, flame retardance, fire resistance, no halogen, low smoke and no toxicity.

[ detailed description ] embodiments

The present application is further described below by way of exemplary embodiments. In addition, if a detailed description of the known art is not necessary to show the features of the present application, it is omitted.

The application provides a waterproof and heat-resistant composition, which comprises the following components in percentage by weight:

80.0-95.0% of polyamide graft polymer;

0-60.0% of flame retardant;

in the polyamide graft polymer, the melting point of polyamide is greater than or equal to 200 ℃.

In one embodiment herein, the polyamide-grafted polymer is a polyamide-grafted polyolefin, which has good long-term water immersion properties.

In one embodiment herein, the polyamide graft polymer is a polyamide selected from nylon 6, nylon 66, or PA 610. Wherein the melting point of nylon 6 is 220 ℃. The melting point of nylon 66 is about 250-260 ℃, and the melting point of PA610 is about 221-224 ℃.

Preferably, the flame retardant is one or more of a brominated flame retardant, an antimony flame retardant and a zinc flame retardant. The brominated flame retardant is selected from brominated flame retardants other than polybrominated biphenyls and polybrominated diphenyl ethers, for example, in the examples of the present application, the brominated flame retardant is selected from one or more of 1, 2-bis (tribromophenoxy) ethane, tetrabromobisphenol a, tetrabromobenzoic anhydride, octabromoether, bis (tetrabromophthalimide) ethane, hexabromocyclododecane. The antimony flame retardant is antimony trioxide. The zinc flame retardant is at least one selected from zinc borate and zinc oxide. The flame retardant can enhance the flame retardancy of the polyamide-grafted polymer.

In one embodiment herein, the flame retardant is selected from decabromodiphenylethane and antimony trioxide. The mass ratio of the decabromodiphenylethane to the antimony trioxide is 3:1, and the flame retardant property of the decabromodiphenylethane flame retardant can reach UL94V-0 level.

In one embodiment of the present application, the waterproof and heat-resistant composition further comprises one or more of the following components in weight percent:

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 18.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

The antioxidant is selected from at least one of phenol-based and sulfur-based antioxidants. The lubricant is selected from metal soaps. The inorganic filler is selected from calcined clay. The crosslinking assistant is selected from multifunctional monomer TMPT.

In one embodiment of the present application, the waterproof and heat-resistant composition further comprises one or more of a colorant, a surfactant, a softener, a plasticizer, a compatibilizer, a stabilizer, a metal complexing agent, an ultraviolet light absorber, and a light stabilizer.

The waterproof heat-resistant composition adopts the polyamide graft polymer, and the mass percent of the polyamide graft polymer is not less than 80%, so that the high mechanical strength, heat resistance, hydrolysis resistance and chemical stability of the waterproof heat-resistant composition are ensured. Compared with common polyamide, the polyamide graft polymer not only has good electrical or mechanical strength, but also has greatly increased hydrolysis resistance, which makes it especially suitable for manufacturing electric wires in the field of rail transit. In addition, more importantly, in the waterproof and heat-resistant composition, the polyamide in the polyamide graft polymer adopts the high-melting-point polyamide with the melting point not lower than 200 ℃, and the adoption of the high-melting-point polyamide ensures that the waterproof and heat-resistant composition has the advantages of excellent mechanical strength, heat-resistant temperature, hydrolysis resistance and chemical stability, and is particularly suitable for manufacturing electric wires in the field of rail transit.

Further, the present application also provides a waterproof heat-resistant insulation structure using the above waterproof heat-resistant composition. The waterproof and heat-resistant composition of the present application has advantages of excellent mechanical strength, heat-resistant temperature, hydrolysis resistance and chemical stability, and is suitable for use in various waterproof and heat-resistant insulating structures, for example, in the production of molded articles such as various pipes, films, sheets and filaments, and in the production of coating materials for various electric wires, cables, wires and the like.

Further, the present application also provides a waterproof and heat-resistant electric wire using the above waterproof and heat-resistant composition. For example, the waterproof and heat-resistant composition can also be applied to the preparation of an insulating layer of a waterproof and heat-resistant electric wire.

In one embodiment of the present application, the waterproof and heat-resistant electric wire comprises an insulating inner layer and an insulating outer layer, the insulating outer layer employs the waterproof and heat-resistant composition, and the insulating inner layer employs an insulating and heat-resistant composition, preferably, a low-polarity, low-water-absorption polymer.

In one embodiment of the present application, the insulating heat-resistant composition comprises a polyolefin resin, and the weight percentage of the polyolefin resin in the insulating heat-resistant composition is 50.0 to 95.0%.

In one embodiment of the present application, the polyolefin resin is selected from one or more of homopolymers and copolymers of polyethylene, ethylene/alpha-olefin copolymers, copolymers of ethylene with unsaturated carboxylic acids, crosslinkable polyolefins, and ethylene-propylene-diene rubbers; in one embodiment of the present application, the polyolefin resin is selected from one or more of Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), Linear Low Density Polyethylene (LLDPE), ethylene- α -octene copolymer (POE), ethylene-vinyl acetate copolymer (EVA), cross-linkable polyolefin (XLPO) or ethylene propylene diene monomer rubber (EPR). The heat-resistant electric wire made of polyolefin resin has excellent mechanical properties, water resistance and electrical insulation, and is relatively inexpensive to manufacture. The insulating inner layer adopts an insulating heat-resistant composition, can maintain the working temperature of 105-150 ℃ for a long time, and has good electrical property, water resistance, oil resistance, acid and alkali resistance and strong filler inclusion.

In one embodiment of the present application, the insulating heat resistant composition further comprises one or more of the following components in weight percent:

0.1 to 50.0 percent of flame retardant;

0.5 to 3.0 percent of antioxidant;

0.1 to 0.8 percent of lubricant;

0.1 to 40.0 percent of inorganic filler;

2.0 to 7.0 percent of crosslinking assistant.

The flame retardant is one or more of a brominated flame retardant, an antimony flame retardant and a zinc flame retardant. The bromine-based flame retardant is selected from bromine-based flame retardants other than polybrominated biphenyls and polybrominated diphenyl ethers, for example, in the examples of the present application, one or more of 1, 2-bis (tribromophenoxy) ethane, tetrabromobisphenol a, tetrabromobenzoic anhydride, octabromoether, bis (tetrabromophthalimide) ethane, hexabromocyclododecane are selected. The antimony flame retardant is antimony trioxide. The zinc flame retardant is at least one selected from zinc borate and zinc oxide.

The antioxidant is selected from at least one of phenol-based and sulfur-based antioxidants. The lubricant is selected from metal soaps. The inorganic filler is selected from calcined clay. The crosslinking assistant is selected from multifunctional monomer TMPT.

In one embodiment of the present application, the insulating heat-resistant composition further comprises one or more of a colorant, a surfactant, a softener, a plasticizer, a compatibilizer, a stabilizer, a metal complexing agent, an ultraviolet light absorber, and a light stabilizer.

In one embodiment of the present application, a method of preparing a waterproof and heat-resistant electric wire of the present application is as follows:

adding the polyamide graft polymer, the flame retardant, the antioxidant, the lubricant, the inorganic filler and the crosslinking assistant into a high-speed mixer, mixing and stirring, and then transferring into an internal mixer for internal mixing to obtain an internal mixed material;

and adding the banburying material into a double-screw extruder to extrude an insulating inner layer and an insulating outer layer, and performing electron irradiation crosslinking after extrusion, wherein the irradiation dose is at least 200 kGy.

It should be noted that the inner insulating layer and the outer insulating layer of the waterproof and heat-resistant electric wire can be extruded separately or can be co-extruded in two layers.

The waterproof and heat-resistant composition is adopted in the insulating outer layer of the waterproof and heat-resistant electric wire, and the waterproof and heat-resistant composition adopts the polyamide graft polymer, and the mass percent of the polyamide graft polymer is not lower than 80%, so that the high mechanical strength, heat resistance, hydrolysis resistance and chemical stability of the waterproof and heat-resistant composition are ensured. Compared with common polyamide, the polyamide graft polymer not only has good electrical or mechanical strength, but also has greatly increased hydrolysis resistance, which makes it especially suitable for manufacturing electric wires in the field of rail transit. In addition, more importantly, in the waterproof and heat-resistant composition, the polyamide in the polyamide graft polymer adopts the high-melting-point polyamide with the melting point of not less than 200 ℃, and the adoption of the high-melting-point polyamide ensures that the waterproof and heat-resistant wire manufactured by the waterproof and heat-resistant composition has the advantages of excellent mechanical strength, heat-resistant temperature, hydrolysis resistance and chemical stability.

The waterproof heat-resistant electric wire not only meets the requirements of various performance indexes specified by European Union standard EN 50306.1-.2 and North American railway Association standard AAR RP-585, but also can adapt to a working environment with high long-term temperature, wherein the insulating inner layer can maintain the working temperature of 105-150 ℃ for a long time, and the insulating outer layer can maintain the working temperature of 200 ℃ for a long time. Meanwhile, the waterproof heat-resistant wire also has excellent long-term water resistance and oil resistance, and has the advantages of chemical corrosion resistance, flame retardance, fire resistance, no halogen, low smoke and no toxicity.

The application also provides the application of the waterproof heat-resistant electric wire in the field of rail transit transportation. The rail transit vehicle wire is required to have good mechanical properties in a high-temperature environment in addition to the properties of the conventional wire. Meanwhile, since the rail transit vehicle wire is exposed to water and oil for a long time, it is also required to have long-term water resistance and oil resistance, and in addition, it is required to have high flame retardancy. The waterproof heat-resistant electric wire has the advantages that the waterproof heat-resistant electric wire is suitable for high-temperature and humid exposure environments and maintains excellent performance for a long time, and is particularly suitable for the field of rail transit transportation.

The properties of the waterproof and heat-resistant composition and the waterproof and heat-resistant wire of the present application are verified by several examples and comparative examples, and the formulations of examples and comparative examples of the waterproof and heat-resistant composition and the waterproof and heat-resistant wire insulation outer layer of the present application are shown in table 1, and the formulations of examples of the waterproof and heat-resistant wire insulation inner layer of the present application are shown in table 2.

TABLE 1 formulation tables of examples of the waterproof and heat-resistant composition of the present application and comparative examples (formulation tables of examples of the waterproof and heat-resistant wire insulation outer layer of the present application and comparative examples of the conventional wire insulation outer layer)

*¹Melting point of PA11 was 185 ℃;

*²the melting point of PA12 was 170-180 ℃.

It should be noted that the present application provides an insulating outer layer of a waterproof and heat-resistant electric wire, which is prepared by using the waterproof and heat-resistant composition of the examples of the present application. That is, the components of the waterproof and heat-resistant wire insulation outer layer of the embodiment of the present application correspond to the formulation of the waterproof and heat-resistant composition of the embodiment of the present application one to one. In addition, a general electric wire was also introduced as a comparison, and electric wires of comparative examples were each prepared using the composition of the above-described comparative example formulation.

Table 2 examples of insulating inner layer of waterproof and heat-resistant electric wire of the present application

Firstly, the tensile strength and elongation of the waterproof heat-resistant electric wire are tested

The temperature resistance of the insulating material is usually simulated by adopting high-temperature oven accelerated aging, the conditions adopted by the insulation heat treatment of the insulation inner layer and the insulation outer layer of the national standard locomotive wire are both 158 ℃ and 168 hours, the tensile strength change rate after the insulation layer of the national standard locomotive wire is aged is +/-13 percent, and the elongation change rate is-13 percent. The smaller the absolute value of the change rate of tensile strength after aging is, the smaller the absolute value of the change rate of elongation is, which indicates that the more the wire has remarkable heat resistance and aging resistance, the longer the service life is, and the better the mechanical strength and heat resistance is.

A. Working temperature test of the insulating outer layer of the waterproof and heat-resistant electric wire of the present application and the insulating outer layer of the comparative example ordinary electric wire

The waterproof and heat-resistant electric wire of the examples of the present application and the ordinary electric wire of the comparative example were subjected to heat treatment under the conditions of 178 ℃ 168 hours, and the tensile strength change rate and elongation change rate after aging are shown in table 3:

TABLE 3

As can be seen from the above, the absolute values of the tensile strength change rate and the elongation change rate of the insulating outer layer material of the waterproof heat-resistant electric wire in the embodiment of the present application after aging are both smaller than those of the marking machine wire tested under the same conditions, which indicates that the insulating outer layer of the waterproof heat-resistant electric wire in the embodiment of the present application has significant heat resistance and aging resistance, long service life, and excellent mechanical strength and heat resistance.

In addition, the insulating outer layer of the waterproof and heat-resistant wire of the example of the present application has the polyamide graft polymer in the waterproof and heat-resistant composition in a mass percentage of 80% or more, while the insulating outer layer of the ordinary wire of comparative example 1 has the polyamide graft polymer in a mass percentage of 60%. As can be seen from the experimental results, the mechanical strength and heat resistance of the insulating outer layer of the ordinary electric wire in comparative example 1 after aging are greatly different from those of the insulating outer layer of the waterproof and heat-resistant electric wire in the examples of the present application.

In the polyamide graft polymer of the insulation outer layer of the ordinary wire of comparative example 2, the selected polyamide is PA11 with a melting point of 185 ℃, and in the polyamide graft polymer of the insulation outer layer of the ordinary wire of comparative example 3, the selected polyamide is PA12 with a melting point of 170-180 ℃, which are both 200 ℃ lower than the melting point of the insulation outer layer material of the waterproof and heat-resistant wire of the embodiment. From the experimental results, it can be seen that the mechanical strength and heat resistance of the insulating outer layer of the ordinary electric wire in comparative example 2 and comparative example 3 after aging are greatly different from those of the insulating outer layer of the waterproof and heat-resistant electric wire in the examples of the present application.

The above test results also show that the waterproof and heat-resistant composition of the present application has excellent mechanical strength and heat resistance because the polyamide of the polyamide graft polymer is a high-melting polyamide having a melting point of not less than 200 ℃ and the polyamide graft polymer is not less than 80% by mass.

B. Working temperature test of insulation inner layer of waterproof heat-resistant electric wire

The inner insulating layer of the waterproof and heat-resistant electric wire according to the example of the present application was subjected to heat treatment under conditions of 220 ℃ 168 hours, and the tensile strength change rate and elongation change rate after aging were as shown in table 4:

TABLE 4

From the above, the insulating inner layer of the waterproof and heat-resistant electric wire in the embodiment of the application has the advantages of remarkable heat resistance and ageing resistance, long service life and excellent mechanical strength and heat resistance.

To sum up, the insulating outer layer of the waterproof heat-resistant electric wire of the embodiment of the present application and the insulating inner layer of the waterproof heat-resistant electric wire of the embodiment of the present application both have significant heat resistance and aging resistance, long service life, and excellent mechanical strength and heat resistance. This also indirectly indicates that in the waterproof and heat-resistant composition of the present application, the polyamide in the polyamide graft polymer is a high-melting polyamide having a melting point of not less than 200 ℃, and the mass percentage of the polyamide graft polymer is not less than 80%, so that the waterproof and heat-resistant composition has excellent mechanical strength and heat resistance when applied to the waterproof and heat-resistant wire of the present application.

And secondly, testing the water resistance and the electrical property of the waterproof and heat-resistant electric wire.

The water-resistant electrical property test is to measure the capacitance change of the wire after being soaked in water for 14 days, and the capacitance change rate of the wire of the national standard machine is (C14-C1)/C1 which is 5 percent. The larger the rate of change in capacitance, the more excellent the water-resistant electrical properties of the wire and the more stable the electrical properties.

The waterproof and heat-resistant electric wire of the present application and the ordinary electric wire of the comparative example were subjected to a water-resistant electric test, and the rate of change in capacitance of each electric wire is shown in table 5.

TABLE 5

From the above, after the waterproof heat-resistant electric wire is soaked in water for 14 days, the capacitance change rate of the waterproof heat-resistant electric wire is far higher than that of a national standard locomotive wire tested under the same condition, and the waterproof heat-resistant electric wire has excellent waterproof electrical performance.

In addition, the rate of change in capacitance of the waterproof and heat-resistant electric wire according to the example of the present application is greater than that of the ordinary electric wires according to comparative example 1, comparative example 2, and comparative example 3 after the waterproof and heat-resistant electric wire is immersed in water for 14 days, which shows that the waterproof and heat-resistant electric wire according to the example of the present application has more excellent waterproof electrical properties than the ordinary electric wire according to the comparative example.

In summary, it is demonstrated that the waterproof and heat-resistant electric wire of the embodiments of the present application has significant waterproof and electrical properties, and it is also indirectly demonstrated that in the waterproof and heat-resistant composition of the present application, the polyamide in the polyamide graft polymer is a high-melting-point polyamide with a melting point of not less than 200 ℃, and the mass percentage of the polyamide graft polymer is not less than 80%, so that the waterproof and heat-resistant composition has excellent mechanical strength and heat resistance when applied to the waterproof and heat-resistant electric wire.

And thirdly, testing the oil resistance of the waterproof heat-resistant electric wire.

The oil resistance test of the electric wire is measured by both the change in mechanical properties and the electrical safety. The condition for the wire treatment of the national label machine is that the mineral oil is treated at 100 ℃ for 70h and the fuel oil is treated at 70 ℃ for 168h (mineral oil resistance type). The results of the line test of the national marking machine are that the tensile strength change rate is-33% and the elongation change rate is-35% after aging. The smaller the absolute value of the tensile strength change rate after aging and the smaller the absolute value of the elongation change rate, the more the wire has remarkable oil resistance, the longer the service life, and the better the mechanical strength and electrical safety. The results of the oil resistance test of the waterproof and heat-resistant electric wire of the present application are shown in table 6.

TABLE 6

As can be seen from the above, after the waterproof heat-resistant electric wire of the embodiment of the present application is subjected to the insulation aging, absolute values of the tensile strength change rate and the elongation change rate are both smaller than those of the marking machine line of the national standard machine tested under the same conditions, which indicates that the waterproof heat-resistant electric wire of the embodiment of the present application has the advantages of significant oil resistance, long service life, and good mechanical strength and electrical safety.

In addition, after the waterproof heat-resistant electric wire in the embodiment of the application is subjected to insulation aging, the absolute values of the change rate of the tensile strength and the change rate of the elongation are smaller than those of the common electric wires in the comparative examples 1,2 and 3, which shows that the waterproof heat-resistant electric wire in the embodiment of the application has more remarkable oil resistance, longer service life, better mechanical strength and better electrical safety compared with the common electric wires in the comparative examples.

In conclusion, the waterproof and heat-resistant electric wire of the embodiment of the application has the advantages of remarkable oil resistance, long service life, and good mechanical strength and electrical safety. Meanwhile, the waterproof and heat-resistant composition adopts the polyamide with the high melting point, the melting point of which is not lower than 200 ℃, in the polyamide graft polymer, and the mass percent of the polyamide graft polymer is not lower than 80%, so that the waterproof and heat-resistant composition has excellent oil resistance, longer service life, and better mechanical strength and electrical safety when being applied to a waterproof and heat-resistant wire.

And fourthly, testing the waterproof heat-resistant wire without halogen, smoke and toxicity.

The halogen-free low-smoke and non-toxic test is carried out by collecting the burned smoke and carrying out acid halogen and toxicity tests, and the national standard locomotive line test has the pH value of 4.8 and the toxicity level ZA 3. Wherein a lower pH indicates a higher acid-halogen property. In the quasi-safety class (class ZA), the relative risk ranking in the toxicity class is ZA3 > ZA2 > ZA 1. The halogen-free low-smoke non-toxic test results of the waterproof heat-resistant wire are shown in Table 7

TABLE 7

Group of	pH value	Grade of toxicity
			EXAMPLE 1 group	6.2	ZA2 stage
EXAMPLE 2 group	6.2	ZA2 stage
			EXAMPLE 3 group	6.3	ZA2 stage
EXAMPLE 4 group	6.3	ZA2 stage
			Comparative example 1 group	5.5	ZA3 stage
Comparative example 2 group	5.3	ZA3 stage
			Comparative example 3 group	5.4	ZA3 stage

As can be seen from the above, after the acid halide property and toxicity tests, the PH values of the waterproof heat-resistant electric wire in the embodiment of the present application are all higher than 4.8, the toxicity levels are all ZA2 levels, and the test results are all superior to the standards of the marking line of the national standard machine, which indicates that the waterproof heat-resistant electric wire in the embodiment of the present application has the characteristics of no halogen, low smoke and no toxicity.

In addition, after the waterproof and heat-resistant electric wire in the embodiment of the application is subjected to acid halide property and toxicity tests, the test results are superior to those of the common electric wires in comparative examples 1,2 and 3, which shows that the waterproof and heat-resistant electric wire in the embodiment of the application has more remarkable advantages of no halogen, low smoke and no toxicity compared with the common electric wires in comparative examples.

In conclusion, the waterproof and heat-resistant electric wire disclosed by the embodiment of the application has the advantages of obvious halogen-free, low smoke and no toxicity. Meanwhile, the waterproof and heat-resistant composition adopts the polyamide with the high melting point, the melting point of which is not lower than 200 ℃, in the polyamide graft polymer, and the mass percent of the polyamide graft polymer is not lower than 80%, so that the waterproof and heat-resistant composition has the advantages of excellent halogen-free property, low smoke and no toxicity when being applied to a waterproof and heat-resistant wire.

Although a few exemplary embodiments of the present application have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the application, the scope of which is defined in the claims and their equivalents.