1. A high flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit is characterized by being prepared from the following components in parts by weight: 100 parts of PVC resin, 8-15 parts of trimellitic acid 810 ester, 3-6 parts of epoxy group-containing hyperbranched polyborosiloxane, 10-15 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 10-20 parts of zinc borate, 15-25 parts of environment-friendly plasticizer, 5-7 parts of heat stabilizer, 4-6 parts of zinc hydroxystannate, 0.5-1.5 parts of antioxidant, 1-3 parts of lubricant, 3-5 parts of amine octamolybdate and 30-45 parts of magnesium hydroxide.

2. The high-flame-retardant class-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the lubricant is lubricant G60.

3. The high-flame-retardant class-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the antioxidant is at least one of an antioxidant 1010, an antioxidant 1076 and an antioxidant 224.

4. The high-flame-retardance type-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the heat stabilizer is at least one of calcium stearate and calcium zinc stabilizer; the environment-friendly plasticizer is epoxidized soybean oil.

5. The high-flame-retardant class-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the particle size of the magnesium hydroxide is 1500-2500 meshes.

6. The high-flame-retardant class-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the cold-resistant solid plasticizer is at least one of HP441, HP661 and HP 4051.

7. The high-flame-retardant class-A low-smoke low-halogen PVC sheathing compound for rail transit according to claim 1, wherein the PVC resin is a PVC resin with a brand number of HG-1300 or US-70.

8. A preparation method of a high flame retardant type A low smoke and low halogen PVC sheathing compound for rail transit according to any one of claims 1 to 7, characterized by comprising the following steps: the components are proportioned according to a proportion, evenly mixed and added into a double-screw extruder for melt extrusion, and a finished product of the high-flame-retardant class-A low-smoke low-halogen PVC sheath material for rail transit is prepared.

9. The preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheathing compound for rail transit according to claim 8, wherein the melt extrusion process specifically comprises the following steps: the heating temperature is 160-.

Background

In recent years, with the progress of science and technology and the development of society, China has become a main export country of rail transit vehicle technology, and a cable for a rail transit vehicle, which is one of main accessories, also completely realizes autonomy; as an indispensable transmission link in rail vehicle electrical systems, the requirements for cable reliability and durability are becoming higher and higher with the trend of technical updates of rail traffic with increasing speeds. The cable sheath material arranged on the outermost layer of the cable is an important protective layer and has the performances of sun resistance, radiation resistance, wear resistance, heat resistance, aging resistance, chemical corrosion resistance and the like. The performance of the cable sheath material directly determines the quality of the cable, and influences the reliability and durability of the cable sheath material. Therefore, it is very important to find a cable sheath material with excellent comprehensive performance for rail transit vehicles.

At present, polyvinyl chloride or rubber is mostly used as a common cable sheath material, the rubber sheath material is difficult to meet the use requirements of people in the aspect of fire resistance and flame retardance, the rubber is easy to melt and decompose under the high-temperature condition, substances which pollute the environment greatly are generated, and the aging resistance and the weather resistance are required to be improved. The polyvinyl chloride rubber material is mainly prepared by mixing PVC material, filler, plasticizer, anti-aging agent, flame retardant, antioxidant and the like, has excellent mechanical and physical properties, flexibility and chemical reagent resistance, is low in price and excellent in processing performance, but can cause environmental pollution in the production process due to the chlorine contained in the components. In addition, the cable material is mainly prepared by mixing a PVC material, a filling material, a plasticizer, an anti-aging agent, a flame retardant, an antioxidant and the like, and the formula raw materials are mainly concentrated on some common components, so that the problems of low technical indexes or high cost of the cable material are caused, such as low volume resistivity, high temperature resistance, low temperature resistance, flame retardance, insulativity and the like, which can not meet the requirements of cable manufacturers on higher electrical properties of insulation-grade sheath materials, and the phenomena of no high temperature resistance, no aging resistance and yellowing and brittleness of the material after an aging test commonly exist.

For example, chinese patent CN103788530B discloses a low-smoke low-halogen flame-retardant insulation-grade PVC sheathing material for an extra-high voltage cable and a preparation thereof, the low-smoke low-halogen flame-retardant insulation-grade PVC sheathing material for the extra-high voltage cable of the invention comprises the following components in parts by weight: 100 parts of PVC resin; 10-20 parts of a plasticizer a; 10-15 parts of calcined argil; 1-3 parts of a flame retardant a; 1-2 parts of pigment carbon black; 2-8 parts of a flame retardant b; 2-5 parts of a heat stabilizer; 5-10 parts of a plasticizer b; 0.1-0.2 part of antioxidant; 1-2 parts of a flame-retardant synergist; 0.2-0.4 part of polyethylene wax; 0.5-1 part of lubricant; 10-20 parts of a plasticizer c; 1-2 parts of metal naphthenate; 0.5-5 parts of capsaicin; 5-10 parts of a smoke suppressor. The low-smoke low-halogen flame-retardant insulation-grade PVC sheath material for the ultrahigh-voltage cable can be widely applied to the outer sheath of the ultrahigh-voltage cable which needs flame retardance and has the effects of preventing rats and termites and the smoke density and the halogen acid gas content during combustion. However, the performance stability of the prepared sheathing compound is required to be further improved due to the compatibility problem among the components, the halogen content in the sheathing compound is required to be further reduced, and the environmental protection performance is required to be further improved.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit and a preparation method thereof. The PVC sheath material has the advantages of good flame retardance, good thermal stability, low smoke density, excellent mechanical property, aging resistance and weather resistance, and sufficient use safety and durability.

In order to achieve the purpose, the invention adopts the technical scheme that: a high flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit is characterized by being prepared from the following components in parts by weight: 100 parts of PVC resin, 8-15 parts of trimellitic acid 810 ester, 3-6 parts of epoxy group-containing hyperbranched polyborosiloxane, 10-15 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 10-20 parts of zinc borate, 15-25 parts of environment-friendly plasticizer, 5-7 parts of heat stabilizer, 4-6 parts of zinc hydroxystannate, 0.5-1.5 parts of antioxidant, 1-3 parts of lubricant, 3-5 parts of amine octamolybdate and 30-45 parts of magnesium hydroxide. Preferably, the lubricant is lubricant G60.

Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 1076 and antioxidant 224.

Preferably, the heat stabilizer is at least one of calcium stearate and calcium zinc stabilizer; the environment-friendly plasticizer is epoxidized soybean oil.

Preferably, the particle size of the magnesium hydroxide is 1500-.

Preferably, the cold-resistant solid plasticizer is at least one of HP441, HP661 and HP 4051.

Preferably, the epoxy-containing hyperbranched polyborosiloxane is epoxy-containing hyperbranched polyborosiloxane prepared according to the method of example 1 in CN 107936475B.

Preferably, the PVC resin is a PVC resin of the brand HG-1300 or US-70.

The invention also aims to provide a preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit, which is characterized by comprising the following steps: the components are proportioned according to a proportion, evenly mixed and added into a double-screw extruder for melt extrusion, and a finished product of the high-flame-retardant class-A low-smoke low-halogen PVC sheath material for rail transit is prepared.

Preferably, the melt extrusion process specifically comprises the following steps: the heating temperature is 160-.

Detailed Description

The following detailed description of preferred embodiments of the invention will be made.

A high flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit is characterized by being prepared from the following components in parts by weight: 100 parts of PVC resin, 8-15 parts of trimellitic acid 810 ester, 3-6 parts of epoxy group-containing hyperbranched polyborosiloxane, 10-15 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 10-20 parts of zinc borate, 15-25 parts of environment-friendly plasticizer, 5-7 parts of heat stabilizer, 4-6 parts of zinc hydroxystannate, 0.5-1.5 parts of antioxidant, 1-3 parts of lubricant, 3-5 parts of amine octamolybdate and 30-45 parts of magnesium hydroxide.

Preferably, the lubricant is lubricant G60.

Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 1076 and antioxidant 224.

Preferably, the heat stabilizer is at least one of calcium stearate and calcium zinc stabilizer; the environment-friendly plasticizer is epoxidized soybean oil.

Preferably, the particle size of the magnesium hydroxide is 1500-.

Preferably, the solid cold-resistant plasticizer is at least one of HP441, HP661 and HP 4051.

Preferably, the epoxy-containing hyperbranched polyborosiloxane is epoxy-containing hyperbranched polyborosiloxane prepared according to the method of example 1 in CN 107936475B.

Preferably, the PVC resin is a PVC resin of the brand HG-1300 or US-70.

The invention also aims to provide a preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit, which is characterized by comprising the following steps: the components are proportioned according to a proportion, evenly mixed and added into a double-screw extruder for melt extrusion, and a finished product of the high-flame-retardant class-A low-smoke low-halogen PVC sheath material for rail transit is prepared.

Preferably, the melt extrusion process specifically comprises the following steps: the heating temperature is 160-.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit provided by the invention has the advantages of good flame retardance, good thermal stability, low smoke density, excellent mechanical property, aging resistance and weather resistance, and sufficient use safety and durability, and the prepared sheath material can reach the performance index of high-flame-retardant A-type low-smoke low-halogen through the interaction of the components.

The invention will be further described with reference to specific examples, but the scope of protection of the invention is not limited thereto:

example 1

The embodiment provides a high-flame-retardant type-A low-smoke low-halogen PVC sheath material for rail transit, which is characterized by being prepared from the following components in parts by weight: 100 parts of PVC resin, 8 parts of trimellitic acid 810 ester, 3 parts of epoxy group-containing hyperbranched polyborosiloxane, 10 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 10 parts of zinc borate, 25 parts of environment-friendly plasticizer, 5 parts of heat stabilizer, 4 parts of zinc hydroxystannate, 0.5 part of antioxidant, 1 part of lubricant, 3 parts of amine octamolybdate and 30 parts of magnesium hydroxide.

The lubricant is lubricant G60; the antioxidant is 1010; the heat stabilizer is a calcium-zinc stabilizer; the environment-friendly plasticizer is epoxidized soybean oil; the particle size of the magnesium hydroxide is 1500 meshes; the solid cold-resistant plasticizer is HP441 cold-resistant plasticizer.

The epoxy group-containing hyperbranched polyborosiloxane is epoxy group-containing hyperbranched polyborosiloxane prepared by the method of example 1 in CN 107936475B; the PVC resin is the PVC resin with the trade mark HG-1300. The preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit is characterized by comprising the following steps of: the components are proportioned according to a proportion, evenly mixed and added into a double-screw extruder for melt extrusion to prepare a finished product of the high-flame-retardant class-A low-smoke low-halogen PVC sheath material for rail transit; the melt extrusion process is specifically as follows: the heating temperature is 160 ℃, the extrusion temperature of a machine head is 130 ℃, the rotation speed of a main screw of the extruder is 190r/min, and the feeding rotation speed is 200 r/min.

Example 2

The formula and the preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit are basically the same as those of the example 1, except that the sheath material is prepared from the following components in parts by weight: 100 parts of PVC resin, 10 parts of trimellitic acid 810 ester, 4 parts of epoxy group-containing hyperbranched polyborosiloxane, 12 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 12 parts of zinc borate, 20 parts of environment-friendly plasticizer, 6 parts of heat stabilizer, 4.5 parts of zinc hydroxystannate, 0.7 part of antioxidant, 1.5 parts of lubricant, 3.5 parts of amine octamolybdate and 35 parts of magnesium hydroxide.

Example 3

The formula and the preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit are basically the same as those of the example 1, except that the sheath material is prepared from the following components in parts by weight: 100 parts of PVC resin, 12 parts of trimellitic acid 810 ester, 3 parts of epoxy group-containing hyperbranched polyborosiloxane, 12 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 12 parts of zinc borate, 20 parts of environment-friendly plasticizer, 6 parts of heat stabilizer, 5 parts of zinc hydroxystannate, 0.7 part of antioxidant, 1.5 parts of lubricant, 4 parts of amine octamolybdate and 40 parts of magnesium hydroxide.

Example 4

The formula and the preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit are basically the same as those of the example 1, except that the sheath material is prepared from the following components in parts by weight: 100 parts of PVC resin, 13 parts of trimellitic acid 810 ester, 3 parts of epoxy group-containing hyperbranched polyborosiloxane, 12 parts of cold-resistant solid plasticizer, 18 parts of zinc borate, 23 parts of environment-friendly plasticizer, 6 parts of heat stabilizer, 5.5 parts of zinc hydroxystannate, 1 part of antioxidant, 2 parts of lubricant, 4.5 parts of amine octamolybdate and 42 parts of magnesium hydroxide.

Example 5

The formula and the preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheath material for rail transit are basically the same as those of the example 1, except that the sheath material is prepared from the following components in parts by weight: 100 parts of PVC resin, 15 parts of trimellitic acid 810 ester, 6 parts of epoxy group-containing hyperbranched polyborosiloxane, 15 parts of cold-resistant solid plasticizer, 12 parts of antimony oxide, 20 parts of zinc borate, 15 parts of environment-friendly plasticizer, 7 parts of heat stabilizer, 6 parts of zinc hydroxystannate, 1.5 parts of antioxidant, 3 parts of lubricant, 5 parts of amine octamolybdate and 45 parts of magnesium hydroxide. Comparative example 1

The present example provides a high flame retardant type a low smoke and low halogen PVC sheathing compound for rail transit, which has a formulation and preparation method substantially the same as example 1, except that ammonium octamolybdate is not included.

Comparative example 2

The formula and the preparation method of the high-flame-retardant A-type low-smoke low-halogen PVC sheathing compound for rail transit are basically the same as those of the sheathing compound in the example 1, except that the sheathing compound does not contain zinc hydroxystannate.

In order to further illustrate the beneficial technical effects of the products of the embodiments of the present application, the samples obtained in the above embodiments 1-5 and comparative examples 1-2 are subjected to performance tests, the test method refers to the current national standard of China, and the test results are shown in table 1. Wherein the thermal aging performance is measured by the change of tensile strength after thermal aging (100 +/-2) DEG C.times.240 h.

TABLE 1

As can be seen from table 1, compared with the comparative example product, the high flame retardant type a low smoke and low halogen PVC sheathing compound for rail transit disclosed in the embodiment of the present invention has less influence on the smoke density of the high flame retardant low smoke and low halogen sheathing compound by ammonium octamolybdate as a smoke suppressor than zinc hydroxystannate, and the smoke density is lower as the contents of ammonium octamolybdate and zinc hydroxystannate are increased.

The above-mentioned embodiments are merely illustrative of the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and implement the invention, and not to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be covered by the scope of the present invention.