1. The preparation method of the environment-friendly impact-resistant PVC insulating material is characterized by comprising the following steps of: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at the condition of 800-plus-1000 rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at the condition of 1200-plus-1500 rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion equipment is 230-250 ℃, the second zone temperature is 260-280 ℃, the third zone temperature is 290-310 ℃, the fourth zone temperature is 315-330 ℃, and the fifth zone temperature is 295-305 ℃;

the polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is any one or the combination of two of dioctyl phthalate, diisodecyl phthalate and diisononyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is any one of calcium carbonate or kaolin; the inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide.

2. The preparation method of the environment-friendly impact-resistant PVC insulation material according to claim 1, wherein the environment-friendly impact-resistant PVC insulation material comprises the following components in percentage by weight: 8-12% of chlorinated polyethylene resin, 40-48% of PVC resin, 2-3% of heat stabilizer, 4-7% of plasticizer, 3-6% of stearic acid, 1-2% of epoxidized soybean oil, 6-9% of inorganic flame retardant, 1.5-2.5% of coupling agent, 2-5% of terpolymer, 5-8% of impact-resistant toughening agent, 0.2-0.3% of antioxidant and the balance of inorganic filler.

3. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 1, wherein in the inorganic flame retardant, the mass ratio of aluminum hydroxide to antimony trioxide is 100: (7-22).

4. The method for preparing an environmentally friendly impact resistant PVC insulation according to claim 1, wherein the coupling agent is silane coupling agent KH572 or silane coupling agent KH 570.

5. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 1, wherein the terpolymer is styrene/isoprene/butadiene terpolymer.

6. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 1, wherein the method for preparing the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; and (2) taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain the styrene-isoprene-butadiene terpolymer.

7. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 1, wherein the impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

8. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 7, wherein the method for preparing the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, adding a silane coupling agent, crystallizing at 60-100 ℃ for 6-24 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

9. The method for preparing environment-friendly impact-resistant PVC insulation material according to claim 8, wherein the molar ratio of the aluminum nitrate to the lithium oxide is (3-10): 1; and the silane coupling agent in the sixth step is A-150 or A-151.

Background

Due to excellent adaptability, chemical property and oil resistance, PVC is widely applied to wires and cables; however, the disadvantage of high dielectric constant relative to high density PVC is signal distortion. Therefore, PVC cannot be used for long distance high frequency communication cables due to its poor dielectric properties.

The PVC resin is a high flame-retardant polymer material, and the oxygen index can reach 47 percent; however, a certain amount of plasticizer is required during processing, and the oxygen index of the composite material is rapidly reduced. The flame retardant is added to improve the flame retardance of PVC, and the currently used flame retardants mainly comprise two types: one is halogen flame retardant containing fluorine, chlorine, bromine and other elements; the other is a halogen-free flame retardant, comprising aluminum hydroxide, magnesium hydroxide, zinc borate, phosphorus flame retardant and intumescent flame retardant. Meanwhile, the halogen flame-retardant material needs to be added with a synergistic flame-retardant component such as a mixture of hydroxylamine stabilizer, nitrone stabilizer, amine oxide stabilizer, benzofuranone stabilizer and the like. The halogen flame retardant and the synergistic component release strong carcinogenic substances such as dioxane, benzofuran and the like and corrosive gases such as hydrogen chloride, hydrogen bromide and the like during combustion, and the environment is seriously damaged. When the mixture of dialkyl tetrachlorophthalic acid and dialkyl tetrabromophthalic acid is used for flame-retardant PVC materials, the PVC materials are lack of low-temperature flow property when used for wire and cable sheath materials and insulating materials.

In the preparation process of PVC, the reason why the material is damaged by the PVC resin in the glass state under the action of stress is that the material is forced to have high elasticity, if the deformation part has structural defects such as impurities, fillers, pores, bubbles and the like, the stress is easily concentrated at the weak part, and the material is rapidly broken, so that the material is damaged when the strength is far lower than the theoretical average strength. Pure PVC resin belongs to brittle materials, and the continuous glass phase can not prevent the severe expansion of cracks under the action of stress, and finally, gaps and crack fracture are formed, so that the impact resistance is poor. The impact resistance of brittle materials is improved by toughening rubber in a widely adopted method. But has not been well developed.

The invention provides a preparation method of an environment-friendly impact-resistant PVC insulating material, aiming at improving the impact resistance of a PVC material, especially the impact resistance at low temperature.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a preparation method of an environment-friendly impact-resistant PVC insulating material.

The technical scheme of the invention is as follows:

a preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at the condition of 800-plus-1000 rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at the condition of 1200-plus-1500 rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion equipment is 230-250 ℃, the second zone temperature is 260-280 ℃, the third zone temperature is 290-310 ℃, the fourth zone temperature is 315-330 ℃ and the fifth zone temperature is 295-305 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is any one or the combination of two of dioctyl phthalate, diisodecyl phthalate and diisononyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is any one of calcium carbonate or kaolin.

Preferably, the environment-friendly impact-resistant PVC insulating material consists of the following components in percentage by weight: 8-12% of chlorinated polyethylene resin, 40-48% of PVC resin, 2-3% of heat stabilizer, 4-7% of plasticizer, 3-6% of stearic acid, 1-2% of epoxidized soybean oil, 6-9% of inorganic flame retardant, 1.5-2.5% of coupling agent, 2-5% of terpolymer, 5-8% of impact-resistant toughening agent, 0.2-0.3% of antioxidant and the balance of inorganic filler.

Preferably, the inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide.

Further preferably, in the inorganic flame retardant, the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: (7-22).

Preferably, the coupling agent is a silane coupling agent KH572 or a silane coupling agent KH 570.

Preferably, the terpolymer is a styrene/isoprene/butadiene terpolymer.

Preferably, the preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to any one of application examples 1, 3, 10, 12, 14, 22, 43 and 48 of Chinese invention patent CN 102432758.

Preferably, the impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

Preferably, the preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, adding a silane coupling agent, crystallizing at 60-100 ℃ for 6-24 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

More preferably, the ligand is any one of Thenoyl Trifluoroacetone (TTA), Benzoyl Trifluoroacetone (BTA), Benzoyl Acetone (BA), o-nitrobenzoic acid (ONBA), trifluoroacetyl acetone (TFA), naphthoyl Trifluoroacetone (TFNB), phenoxyacetic acid (HPOA), dibenzoyl methane (DBM) or acetylacetone (acac); the molar ratio of the aluminum nitrate to the lithium oxide is (3-10): 1; and the silane coupling agent in the sixth step is A-150 or A-151.

The invention has the advantages that: the preparation method of the environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material; the environment-friendly impact-resistant PVC insulating material is added with the inorganic flame retardant which is a mixed flame retardant of aluminum hydroxide and antimony trioxide, does not contain heavy metals, and is environment-friendly and safe.

In order to further improve the impact resistance of the PVC insulating material, the styrene/isoprene/butadiene terpolymer and the modified lithium aluminum hydrotalcite are added, wherein the content of each monomer in the styrene/isoprene/butadiene terpolymer has a great influence on the impact resistance of the insulating material at low temperature. The environment-friendly impact-resistant PVC insulating material has very good impact resistance at the temperature of-50 ℃.

Detailed Description

Example 1

A preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at 850rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at 1350rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion device is 240 ℃, the second zone temperature is 270 ℃, the third zone temperature is 295 ℃, the fourth zone temperature is 320 ℃, and the fifth zone temperature is 300 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is dioctyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is calcium carbonate.

The environment-friendly impact-resistant PVC insulating material comprises the following components in percentage by weight: 10% of chlorinated polyethylene resin, 43% of PVC resin, 2.5% of heat stabilizer, 5% of plasticizer, 4.5% of stearic acid, 1.8% of epoxidized soybean oil, 7.5% of inorganic flame retardant, 1.7% of coupling agent, 3.2% of terpolymer, 7.5% of impact-resistant toughening agent, 0.25% of antioxidant and the balance of inorganic filler.

The inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide; the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: 17.

the coupling agent is a silane coupling agent KH 572.

The terpolymer is a styrene/isoprene/butadiene terpolymer.

The preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to application example 1 of Chinese invention patent CN 102432758.

The impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

The preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, then adding a silane coupling agent, crystallizing at 85 ℃ for 12 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

The ligand is thenoyltrifluoroacetone (TTA); the molar ratio of the aluminum nitrate to the lithium oxide is 7: 1; and the silane coupling agent in the sixth step is A-150.

Example 2

A preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at 1000rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at 1200rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion device is 250 ℃, the second zone temperature is 260 ℃, the third zone temperature is 310 ℃, the fourth zone temperature is 315 ℃, and the fifth zone temperature is 295 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is prepared from dioctyl phthalate and diisodecyl phthalate in a mass ratio of 1: 2 in combination; the antioxidant is a phenol antioxidant; the inorganic filler is kaolin.

The environment-friendly impact-resistant PVC insulating material comprises the following components in percentage by weight: 12% of chlorinated polyethylene resin, 40% of PVC resin, 3% of heat stabilizer, 4% of plasticizer, 6% of stearic acid, 1% of epoxidized soybean oil, 9% of inorganic flame retardant, 1.5% of coupling agent, 5% of terpolymer, 5% of impact-resistant toughening agent, 0.3% of antioxidant and the balance of inorganic filler.

The inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide; the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: 7.

the coupling agent is a silane coupling agent KH 570.

The terpolymer is a styrene/isoprene/butadiene terpolymer.

The preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to application example 10 of Chinese invention patent CN 102432758.

The impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

The preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, then adding a silane coupling agent, crystallizing at 100 ℃ for 6 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

The ligand is Benzoyl Trifluoroacetone (BTA); the molar ratio of the aluminum nitrate to the lithium oxide is 10: 1; and the silane coupling agent in the sixth step is A-150.

Example 3

A preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at 800rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at 1500rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion device is 230 ℃, the second zone temperature is 280 ℃, the third zone temperature is 290 ℃, the fourth zone temperature is 330 ℃ and the fifth zone temperature is 295 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is diisononyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is calcium carbonate.

The environment-friendly impact-resistant PVC insulating material comprises the following components in percentage by weight: 8% of chlorinated polyethylene resin, 48% of PVC resin, 2% of heat stabilizer, 7% of plasticizer, 3% of stearic acid, 2% of epoxidized soybean oil, 6% of inorganic flame retardant, 2.5% of coupling agent, 2% of terpolymer, 8% of impact-resistant toughening agent, 0.3% of antioxidant and the balance of inorganic filler.

The inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide; the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: 22.

the coupling agent is a silane coupling agent KH 572.

The terpolymer is a styrene/isoprene/butadiene terpolymer.

The preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to application example 12 of Chinese invention patent CN 102432758.

The impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

The preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, then adding a silane coupling agent, crystallizing at 60 ℃ for 24 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

The ligand is Trifluoroacetylacetone (TFA); the molar ratio of the aluminum nitrate to the lithium oxide is 3: 1; and the silane coupling agent in the sixth step is A-151.

Example 4

A preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at 950rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at 1500rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion device was 230 ℃, the second zone temperature was 275 ℃, the third zone temperature was 290 ℃, the fourth zone temperature was 325 ℃, and the fifth zone temperature was 295 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is dioctyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is kaolin.

The environment-friendly impact-resistant PVC insulating material comprises the following components in percentage by weight: 9% of chlorinated polyethylene resin, 48% of PVC resin, 2.5% of heat stabilizer, 7% of plasticizer, 4.5% of stearic acid, 2% of epoxidized soybean oil, 7% of inorganic flame retardant, 2.5% of coupling agent, 4% of terpolymer, 8% of impact-resistant toughening agent, 0.2% of antioxidant and the balance of inorganic filler.

The inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide; the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: 15.

the coupling agent is a silane coupling agent KH 570.

The terpolymer is a styrene/isoprene/butadiene terpolymer.

The preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to application example 22 of Chinese invention patent CN 102432758.

The impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

The preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, then adding a silane coupling agent, crystallizing at 90 ℃ for 24 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

The ligand is Trifluoroacetylacetone (TFA); the molar ratio of the aluminum nitrate to the lithium oxide is 5: 1; and the silane coupling agent in the sixth step is A-150.

Example 5

A preparation method of an environment-friendly impact-resistant PVC insulating material comprises the following steps: mixing and stirring chlorinated polyethylene resin, PVC resin, a heat stabilizer, a plasticizer, stearic acid, epoxidized soybean oil, an inorganic flame retardant, a coupling agent and a terpolymer for the first time at 1000rpm according to a proportion, then adding an impact-resistant toughening agent, an antioxidant and an inorganic filler, and mixing and stirring for the second time at 1280rpm to obtain a mixture; putting the mixture into an extrusion device for mixing, extruding and granulating to prepare the environment-friendly impact-resistant PVC insulating material;

the first zone temperature of the extrusion device is 250 ℃, the second zone temperature is 270 ℃, the third zone temperature is 310 ℃, the fourth zone temperature is 320 ℃, and the fifth zone temperature is 305 ℃.

The polymerization degree of the PVC resin is 2000-2300; the heat stabilizer is a calcium-zinc composite stabilizer; the plasticizer is dioctyl phthalate; the antioxidant is a phenol antioxidant; the inorganic filler is calcium carbonate.

The environment-friendly impact-resistant PVC insulating material comprises the following components in percentage by weight: 12% of chlorinated polyethylene resin, 42% of PVC resin, 3% of heat stabilizer, 5.5% of plasticizer, 6% of stearic acid, 1.7% of epoxidized soybean oil, 9% of inorganic flame retardant, 1.8% of coupling agent, 5% of terpolymer, 5.5% of impact-resistant toughening agent, 0.3% of antioxidant and the balance of inorganic filler.

The inorganic flame retardant is a mixed flame retardant of aluminum hydroxide and antimony trioxide; the mass ratio of the aluminum hydroxide to the antimony trioxide is 100: 11.

the coupling agent is a silane coupling agent KH 572.

The terpolymer is a styrene/isoprene/butadiene terpolymer.

The preparation method of the styrene/isoprene/butadiene terpolymer comprises the following steps: dispersing a catalyst in an organic solvent to obtain a catalyst solution; the catalyst comprises: the reagent comprises a rare earth complex, an organic boron salt and an alkylating agent, wherein the rare earth complex is a rare earth borohydride; taking a styrene monomer, an isoprene monomer and a butadiene monomer as raw materials, and carrying out catalytic polymerization reaction on the catalyst solution at the temperature of minus 20-80 ℃ to obtain a styrene-isoprene-butadiene terpolymer; the preparation method of the styrene/isoprene/butadiene terpolymer refers to application example 48 of Chinese invention patent CN 102432758.

The impact-resistant toughening agent is modified lithium aluminum hydrotalcite.

The preparation method of the modified lithium aluminum hydrotalcite comprises the following steps:

the method comprises the following steps: dissolving sodium metaaluminate and sodium hydroxide in deionized water to prepare a solution A;

step two: dissolving aluminum nitrate in deionized water to prepare a solution B;

step three: dissolving lithium oxide with dilute hydrochloric acid, and pouring into the solution B to prepare a solution C;

step four: dissolving the ligand in sodium stearate to prepare mixed slurry D;

step five: under the action of strong stirring or ultrasonic waves, dropwise adding the solution A and the solution C into the mixed slurry D to prepare mixed slurry E, aging, performing suction filtration, and drying a filter cake to obtain lithium aluminum hydrotalcite;

step six: dispersing lithium aluminum hydrotalcite in an organic solvent to prepare a suspension, adding a silane coupling agent, crystallizing at 60-100 ℃ for 6-24 hours, washing with ethanol, and drying to obtain the lithium aluminum hydrotalcite.

The ligand is thenoyltrifluoroacetone (TTA); the molar ratio of the aluminum nitrate to the lithium oxide is 10: 1; and the silane coupling agent in the sixth step is A-150.

Comparative example 1

The styrene/isoprene/butadiene terpolymer of example 1 was replaced with a commercially available methyl methacrylate/butadiene/styrene terpolymer (Nanhai Dali M-080), and the remaining proportions and preparation were unchanged.

Comparative example 2

The modified lithium aluminum hydrotalcite in example 1 was replaced with modified magnesium aluminum hydrotalcite (the modification method was unchanged), and the rest of the compounding ratio and the preparation method were unchanged.

Comparative example 3

The modified lithium aluminum hydrotalcite in example 1 was replaced with unmodified lithium aluminum hydrotalcite (step six was removed), and the rest of the formulation and preparation method were unchanged.

Comparative example 4

The preparation method of the styrene/isoprene/butadiene terpolymer in the embodiment 1 is respectively replaced by the application embodiment 2 of the Chinese invention patent CN102432758, and the rest proportion and the preparation method are not changed.

Comparative example 5

The preparation method of the styrene/isoprene/butadiene terpolymer described in example 1 was replaced with the application example 29 of the chinese invention patent CN102432758, respectively, and the rest of the compounding ratio and the preparation method were not changed.

Comparative example 6

The preparation method of the styrene/isoprene/butadiene terpolymer described in example 1 was replaced with the application example 39 of the chinese invention patent CN102432758, respectively, and the rest of the compounding ratio and the preparation method were not changed.

Comparative example 7

The preparation method of the styrene/isoprene/butadiene terpolymer described in example 1 was replaced with the application example 51 of the chinese invention patent CN102432758, respectively, and the rest of the compounding ratio and the preparation method were not changed.

The volume resistivity and low-temperature impact brittleness test of the environment-friendly impact-resistant PVC insulating material prepared in the examples 1-5 and the comparative examples 1-7 of the invention is carried out according to the test standards specified in GB/1410-2006 and GB/T5470-2008, and the specific test results are shown in Table 1.

Table 1: test results of the PVC insulators prepared in examples 1 to 5 and comparative examples 1 to 7;

remarking: the test sample size was 20.00mm ± 0.25mm × 2.50mm ± 0.05mm × 2.00mm ± 0.10 mm; 30 samples were tested.

From the above test data, it can be known that the kind of terpolymer and the preparation method of styrene/isoprene/butadiene terpolymer used in the present invention have a great influence on the low temperature impact resistance of PVC insulation, and it can be inferred from the test data that:

1. any one of the content ratios (mol%) of the three monomers of styrene, isoprene and butadiene lower than 20% can have great influence on the low-temperature impact property;

2. when the content ratio of isoprene is lower than that (mol%) of butadiene and is higher than 4 mol%, the low-temperature impact property is greatly influenced;

3. under the condition that the content ratio (mol%) of three monomers of styrene, isoprene and butadiene is higher than 20%, and the content ratio (mol%) of isoprene is higher than that of butadiene or is not greatly different from that of butadiene (the difference is lower than 4 mol%), the PVC insulating material has very good low-temperature impact resistance.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.