Novel PVC (polyvinyl chloride) stabilizer as well as preparation method and application thereof in automobile cable

Abstract

The invention provides a novel PVC (Polyvinyl Chloride) stabilizer as well as a preparation method and application thereof in an automobile cable, and relates to the technical field of PVC stabilizers. The novel PVC stabilizer provided by the invention comprises the following components in parts by mass: 10-15 parts of modified magnesium aluminum hydrotalcite, 2-3 parts of calcium stearate and 2-3 parts of zinc stearate, the modified magnesium-aluminum hydrotalcite comprises a magnesium-aluminum hydrotalcite matrix and a phosphate modified layer growing on the surface of the magnesium-aluminum hydrotalcite matrix, and the surface of the phosphate modified layer is coated with a nitrogen-containing carbon layer. According to the invention, the phosphate modified layer and the nitrogen-containing carbon layer are added on the surface of the magnesium-aluminum hydrotalcite matrix, and the phosphate modified layer can interact with calcium ions and zinc ions, so that the synergistic ability of the magnesium-aluminum hydrotalcite matrix with calcium stearate and zinc stearate can be improved, and the long-acting thermal stability of PVC is made up.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC stabilizers, and particularly to a novel PVC stabilizer, a preparation method thereof, and an application thereof in automotive cables. Background Art

[0002] With the development of the global economy and the continuous progress of technology, the automotive industry is undergoing profound changes. In recent years, traditional fuel vehicles have been continuously upgraded and replaced, and new energy vehicles have shown an explosive growth trend. New energy vehicles, with their advantages of environmental protection, high efficiency, and intelligence, have gradually become an important development direction in the automotive market. When automobiles develop towards a direction of higher efficiency, higher intelligence, and higher electrification level, automotive cables that play a role in transmitting electrical energy and signals become increasingly crucial.

[0003] Automotive cables, like the nerves and blood vessels of the human body, connect various electrical equipment and control systems in the vehicle. Whether it is the ignition system of the engine, the lighting system, the air conditioning system, the autonomous driving assistance system, or the audio and video entertainment system in the cockpit, all rely on the support of cables. Therefore, automotive cables need good electrical performance to ensure the efficient transmission of electrical energy and electrical signals, and also need to have good mechanical properties to withstand the tensile changes suffered by the vehicle during driving. In addition, since the cables are prone to being affected by high temperatures in the engine compartment during the operation of the vehicle, automotive cables also need to have good heat resistance.

[0004] Polyvinyl chloride (PVC) is a widely used thermoplastic. It has good electrical insulation performance, high mechanical strength, and flexibility, and can well isolate electric current and meet the requirements of automotive cables for bending and stretching during installation and use. Therefore, PVC is commonly used to make the insulation layer and sheath of automotive cables to isolate electric current and protect the overall cable to prevent the cable from being damaged by external mechanical forces. However, traditional PVC materials are thermosensitive plastics and are prone to dehydrochlorination reactions during use, which increases the degradation rate of PVC and causes a sharp decline in performance.

[0005] In the prior art, in order to improve the thermal stability of PVC materials, heat stabilizers are often added during the processing process to inhibit the dehydrochlorination reaction of PVC materials during heating and delay the degradation rate of PVC. Commonly used heat stabilizers mainly include lead salts, metal soaps, organotin compounds, and composite heat stabilizers. Among them, lead salts and organotin compounds are toxic and difficult to be used in automotive cables, while the thermal stability effect of metal soaps is limited, and the zinc salts among them are prone to zinc burning, which will instead accelerate the degradation of PVC. Therefore, there is an urgent need to provide a solution to improve the above problems. Summary of the Invention

[0006] The object of the present invention is to provide a novel PVC stabilizer, its preparation method and its application in automotive cables.

[0007] In the first aspect, a novel PVC stabilizer provided by the present invention comprises, by mass: 10 - 15 parts of modified magnesium aluminum hydrotalcite, 2 - 3 parts of calcium stearate, and 2 - 3 parts of zinc stearate; the modified magnesium aluminum hydrotalcite comprises a magnesium aluminum hydrotalcite matrix and a phosphate modification layer grown on the surface of the magnesium aluminum hydrotalcite matrix, and a nitrogen-containing carbon layer is coated on the surface of the phosphate modification layer.

[0008] Optionally, the preparation method of the modified magnesium aluminum hydrotalcite comprises the following steps: performing surface treatment on magnesium aluminum hydrotalcite to obtain a precursor; performing a solvothermal reaction on the precursor in a phosphorus-containing nitrate solution to obtain an intermediate; stirring and mixing the intermediate in a nitrogen-containing organic solution and then separating and calcining to obtain the modified magnesium aluminum hydrotalcite.

[0009] Optionally, when performing surface treatment on magnesium aluminum hydrotalcite to obtain a precursor, the preparation method of the magnesium aluminum hydrotalcite comprises: mixing and dissolving magnesium nitrate and aluminum nitrate to obtain a mixed metal solution; mixing the mixed metal solution with an alkali solution and performing a hydrothermal reaction at 100°C - 200°C and then separating to obtain magnesium aluminum hydrotalcite.

[0010] Optionally, the molar ratio of the magnesium nitrate to the aluminum nitrate is (2 - 4):1.

[0011] Optionally, the alkali solution comprises a sodium hydroxide solution.

[0012] Optionally, the particle size of the magnesium aluminum hydrotalcite is 1μm - 20μm.

[0013] Optionally, when performing surface treatment on magnesium aluminum hydrotalcite to obtain a precursor, stirring and reacting the magnesium aluminum hydrotalcite in a nitrogen-containing silane solution and then separating and drying.

[0014] Optionally, the nitrogen-containing silane solute in the nitrogen-containing silane solution includes γ-aminopropyltrimethoxysilane, γ- One of aminopropyltriethoxysilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0015] Optionally, the mass ratio of the magnesium aluminum hydrotalcite to the nitrogen-containing silane solute in the nitrogen-containing silane solution is 1:(0.1 - 0.15).

[0016] Optionally, stirring and reacting the magnesium aluminum hydrotalcite in a nitrogen-containing silane solution at 40°C - 45°C.

[0017] Optionally, the phosphorus-containing solute in the phosphorus-containing nitrate solution is one of sodium phosphate, sodium hydrogen phosphate, and sodium dihydrogen phosphate.

[0018] Optionally, the nitrate solute in the phosphorus-containing nitrate solution comprises one of rare earth nitrate salts and lithium nitrate.

[0019] Optionally, the molar ratio of phosphorus in the phosphorus-containing nitrate solution to nitrate solute is 1:(0.2 - 0.3).

[0020] Optionally, the nitrogen-containing organic solute in the nitrogen-containing organic solution includes one of melamine and polyacrylamide.

[0021] Optionally, the mass ratio of the intermediate to the nitrogen-containing organic solute in the nitrogen-containing organic solution is 1:(0.1 - 0.2).

[0022] Optionally, after the intermediate is stirred and mixed in the nitrogen-containing organic solution, solid-liquid separation is carried out and sintering and curing are carried out in a nitrogen-containing atmosphere at 300°C - 400°C to obtain modified magnesium aluminum hydrotalcite.

[0023] Optionally, the solid-liquid separation includes filtration or suction filtration.

[0024] Optionally, the nitrogen-containing atmosphere includes nitrogen or ammonia.

[0025] In a second aspect, the present invention also provides a preparation method of any one of the above optional stabilizers, including: stirring and kneading modified magnesium aluminum hydrotalcite, calcium stearate, and zinc stearate to obtain a stabilizer.

[0026] In a third aspect, the present invention also provides an application of any one of the above optional stabilizers in automotive cables.

[0027] A novel PVC stabilizer provided by the present invention has at least one of the following beneficial technical effects compared with the prior art:

[0028] 1. The modified magnesium aluminum hydrotalcite has a layered structure and can well absorb hydrogen chloride generated by the degradation of PVC, thereby inhibiting the autocatalytic degradation reaction of PVC. At the same time, it can produce a synergistic effect with calcium stearate and zinc stearate, thereby improving the overall dispersion of the stabilizer in the PVC material and making up for the long-term thermal stability of PVC.

[0029] 2. By adding a phosphate modification layer and a nitrogen-containing carbon layer on the surface of the magnesium aluminum hydrotalcite matrix, the phosphate modification layer can interact with calcium ions and zinc ions, thereby improving its synergistic ability with calcium stearate and zinc stearate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow block diagram of a preparation method of a modified magnesium aluminum hydrotalcite provided by the present invention. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0032] The present invention provides a novel PVC stabilizer, which includes 10 - 15 parts by mass of modified magnesium-aluminum hydrotalcite, 2 - 3 parts of calcium stearate, and 2 - 3 parts of zinc stearate. In fact, the modified magnesium-aluminum hydrotalcite has a layered structure and can well absorb hydrogen chloride generated by PVC degradation, thereby inhibiting the autocatalytic degradation reaction of PVC. At the same time, it can produce a synergistic effect with calcium stearate and zinc stearate, thereby improving the overall dispersibility of the stabilizer in the PVC material and making up for the long-term thermal stability of PVC.

[0033] Specifically, the modified magnesium-aluminum hydrotalcite includes a magnesium-aluminum hydrotalcite matrix and a phosphate modification layer grown on the surface of the magnesium-aluminum hydrotalcite matrix, and a nitrogen-containing carbon layer is coated on the surface of the phosphate modification layer. In fact, by adding a phosphate modification layer and a nitrogen-containing carbon layer on the surface of the magnesium-aluminum hydrotalcite matrix, the phosphate modification layer can interact with calcium ions and zinc ions, thereby improving its synergistic ability with calcium stearate and zinc stearate.

[0034] In addition, the phosphate modification layer grows on the surface of the magnesium-aluminum hydrotalcite matrix, which can play a barrier role, prevent external factors from damaging the layered structure of the magnesium-aluminum hydrotalcite matrix, and inhibit the excessive release of ions in the magnesium-aluminum hydrotalcite, which can effectively improve the structural stability of the modified magnesium-aluminum hydrotalcite and at the same time improve the long-term effect of thermal stability after adding it to the PVC material. At the same time, the nitrogen-containing carbon layer on the surface of the phosphate modification layer can significantly improve the dispersibility of the magnesium-aluminum hydrotalcite in the PVC material, thereby being conducive to improving the compatibility of the modified magnesium-aluminum hydrotalcite.

[0035] In some embodiments, refer to Figure 1 , the preparation method of the modified magnesium-aluminum hydrotalcite includes the following steps:

[0036] S1. Perform surface treatment on the magnesium-aluminum hydrotalcite to obtain a precursor;

[0037] S2. Perform a solvothermal reaction on the precursor in a nitrate solution containing phosphorus to obtain an intermediate;

[0038] S3. Stir and mix the intermediate in a nitrogen-containing organic solution and then separate and calcine it to obtain the modified magnesium-aluminum hydrotalcite.

[0039] In fact, by surface-treating the magnesium aluminum hydrotalcite in step S1, the active sites on the surface of the magnesium aluminum hydrotalcite can be effectively increased, and at the same time, its surface can be cleaned, thereby promoting the better reaction of the precursor with the phosphorus-containing nitrate in step S2, so as to in-situ generate a phosphate modification layer on the surface of the precursor. When the intermediate is stirred in the nitrogen-containing organic solution in step S3, the nitrogen-containing organic solution can interact with the surface of the intermediate, thereby introducing nitrogen-containing organic substances on the intermediate surface, and after calcination, it is carbonized to form a nitrogen-containing carbon layer.

[0040] In some embodiments, the preparation method of the magnesium aluminum hydrotalcite used in step S1: Mix and dissolve magnesium nitrate and aluminum nitrate to obtain a mixed metal solution; mix the mixed metal solution with an alkali solution and carry out a hydrothermal reaction at 100°C - 200°C, and then separate to obtain the magnesium aluminum hydrotalcite. In fact, when preparing the magnesium aluminum hydrotalcite, not only the solvothermal method can be used, but also the coprecipitation method can be used, as long as the required magnesium aluminum hydrotalcite can be prepared. In addition, the magnesium aluminum hydrotalcite can not only be synthesized by itself, but also commercially available conventional products can be used.

[0041] In some further embodiments, when mixing and dissolving magnesium nitrate and aluminum nitrate in the preparation of the magnesium aluminum hydrotalcite, the molar ratio of magnesium nitrate to aluminum nitrate used is (2 - 4):1, whereby a magnesium aluminum hydrotalcite with a specific magnesium-aluminum molar ratio can be prepared, so as to effectively improve the stabilization efficiency after adding to the PVC system. Specifically, the alkali solution includes a sodium hydroxide solution, and the particle size of the prepared magnesium aluminum hydrotalcite is 1μm - 20μm.

[0042] In some embodiments, when surface-treating the magnesium aluminum hydrotalcite in step S1, the magnesium aluminum hydrotalcite can be stirred and reacted in a nitrogen-containing silane solution and then separated and dried. In fact, by treating in the nitrogen-containing silane solution, nitrogen- and silicon-containing functional groups can be introduced on the surface of the magnesium aluminum hydrotalcite, which is beneficial to increasing the number of surface active sites of the magnesium aluminum hydrotalcite and improving the dispersibility of the precursor.

[0043] In some embodiments, when surface-treating the magnesium aluminum hydrotalcite in step S1, the nitrogen-containing silane solute in the used nitrogen-containing silane solution includes one of γ-aminopropyltrimethoxysilane (KH-540), γ-aminopropyltriethoxysilane (KH-550), and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (A-1120). In addition, the mass ratio of the magnesium aluminum hydrotalcite to the nitrogen-containing silane solute is 1:(0.1 - 0.15), so that better surface treatment performance can be achieved.

[0044] In some embodiments, when surface-treating the magnesium-aluminum hydrotalcite in step S1, to improve the surface treatment effect and treatment efficiency, the magnesium-aluminum hydrotalcite can be stirred and reacted in a nitrogen-containing silane solution at 40°C - 45°C. In fact, the nitrogen-containing silane solution can be preheated in a water bath environment and then magnesium-aluminum hydrotalcite is added for mechanical mixing. Specifically, the mechanical mixing means used can be stirring and / or ultrasonic.

[0045] In some embodiments, the phosphorus-containing solute in the phosphorus-containing nitrate solution used in step S2 is one of sodium phosphate, sodium hydrogen phosphate, and sodium dihydrogen phosphate, and the nitrate solute is one of rare earth nitrate salts and lithium nitrate. In fact, by subjecting the precursor to a solvothermal reaction in the phosphorus-containing nitrate solution, it can promote the reaction to generate phosphate and grow on the surface of the precursor. Specifically, the solvent in the phosphorus-containing nitrate solution is an alcohol-water mixture, and the alcohol includes methanol and / or ethanol.

[0046] In some embodiments, the molar ratio of phosphorus in the phosphorus-containing solute to the nitrate solute in the phosphorus-containing nitrate solution used in step S2 is 1:(0.2 - 0.3), which is beneficial to the formation of a stable phosphate modification layer. In addition, after adding the precursor to the phosphorus-containing nitrate solution in step S2, the reaction is carried out at 150°C - 180°C for 12h - 24h and then separated to obtain the intermediate.

[0047] In some embodiments, the nitrogen-containing organic solute in the nitrogen-containing organic solution used in step S3 includes one of melamine and polyacrylamide, and the mass ratio of the intermediate to the nitrogen-containing organic solute in the nitrogen-containing organic solution is 1:(0.1 - 0.2). In addition, after stirring and mixing the intermediate in the nitrogen-containing organic solution, solid-liquid separation is carried out and sintered and cured in a nitrogen-containing atmosphere at 300°C - 400°C to obtain the modified magnesium-aluminum hydrotalcite, where the solid-liquid separation includes filtration or suction filtration, and the nitrogen-containing atmosphere includes nitrogen or ammonia.

[0048] The present invention also provides a preparation method of any of the above optional stabilizers, including: stirring and kneading the modified magnesium-aluminum hydrotalcite, calcium stearate, and zinc stearate to obtain the stabilizer. In fact, the particle size of the obtained stabilizer is 1μm - 20μm.

[0049] Preparation Example 1

[0050] This Preparation Example 1 provides a preparation method of modified magnesium-aluminum hydrotalcite, including the following steps:

[0051] S0. Mix magnesium nitrate and aluminum nitrate in a molar ratio of 3:1 and dissolve them in deionized water to obtain a mixed metal solution, and mix the mixed metal solution with an alkali solution (molar ratio of sodium hydroxide to sodium carbonate 1:1) and transfer it to a high-pressure reaction kettle. Carry out a hydrothermal reaction at 130°C for 18h and naturally cool to room temperature. Perform solid-liquid separation and wash and dry to obtain magnesium-aluminum hydrotalcite;

[0052] S1. Add magnesium aluminum hydrotalcite to the nitrogen-containing silane solution (the mass ratio of KH-540 to magnesium aluminum hydrotalcite is 0.1:1) at a solid-liquid ratio of 0.08 g / mL, stir at a speed of 200 rpm in a 45°C water bath environment, apply ultrasonic treatment at 10 kHz for 10 min, then let it stand for 30 min. After filtration and separation and washing the precipitate, dry it in a 70°C hot air dryer until constant weight to obtain the precursor;

[0053] S2. Add the precursor to the phosphorus-containing nitrate solution (the molar ratio of sodium phosphate to lithium nitrate is 1:0.25, and the volume ratio of methanol to water is 0.05:0.95) at a solid-liquid ratio of 0.08 g / mL, stir and mix, then transfer it to a high-pressure reaction kettle lined with polytetrafluoroethylene, react at 160°C for 18 h, and then naturally cool to room temperature. After solid-liquid separation and washing the precipitate, dry it in a 60°C vacuum dryer until constant weight to obtain the intermediate;

[0054] S3. Add the intermediate to the nitrogen-containing organic solution (the mass ratio of the intermediate to melamine is 1:0.15) at a solid-liquid ratio of 0.08 g / mL, apply ultrasonic treatment at a frequency of 20 kHz for 20 min in a 50°C water bath environment, then let it stand for 10 min. Repeat the ultrasonic treatment and standing process 3 times (for a total of 1.5 h), then perform solid-liquid separation and wash the precipitate with absolute ethanol. After drying it in a 50°C vacuum dryer until constant weight, place it in a tubular furnace and sinter and solidify it in a nitrogen atmosphere at 350°C, and then crush it to obtain the modified magnesium aluminum hydrotalcite.

[0055] Preparation Example 2

[0056] This Preparation Example 2 provides a method for preparing modified magnesium aluminum hydrotalcite, including the following steps:

[0057] D0. Mix magnesium nitrate and aluminum nitrate at a molar ratio of 3:1 and dissolve them in deionized water to obtain a mixed metal solution. Mix the mixed metal solution with an alkali solution (the molar ratio of sodium hydroxide to sodium carbonate is 1:1), transfer it to a high-pressure reaction kettle, perform hydrothermal reaction at 130°C for 18 h, and then naturally cool to room temperature. After solid-liquid separation and washing and drying, obtain magnesium aluminum hydrotalcite;

[0058] D1. Add magnesium aluminum hydrotalcite to the nitrogen-containing silane solution (the mass ratio of KH-540 to magnesium aluminum hydrotalcite is 0.1:1) at a solid-liquid ratio of 0.08 g / mL, stir at a speed of 200 rpm in a 45°C water bath environment, apply ultrasonic treatment at 10 kHz for 10 min, then let it stand for 30 min. After filtration and separation and washing the precipitate, dry it in a 70°C hot air dryer until constant weight to obtain the precursor;

[0059] D2. Add the precursor to the nitrate solution containing phosphorus (the molar ratio of sodium phosphate to lithium nitrate is 1:0.25, and the volume ratio of methanol to water is 0.05:0.95) at a solid-liquid ratio of 0.08 g / mL, stir and mix, then transfer it to a high-pressure reaction kettle with a polytetrafluoroethylene liner. React at 160 °C for 18 h and then naturally cool to room temperature. After solid-liquid separation and washing the precipitate, dry it in a vacuum drying oven at 60 °C until constant weight to obtain the modified magnesium-aluminum hydrotalcite.

[0060] Preparation Example 3

[0061] This Preparation Example 3 provides a method for preparing a modified magnesium-aluminum hydrotalcite, including the following steps:

[0062] D0. Mix magnesium nitrate and aluminum nitrate at a molar ratio of 3:1 and dissolve them in deionized water to obtain a mixed metal solution. Mix the mixed metal solution with an alkali solution (the molar ratio of sodium hydroxide to sodium carbonate is 1:1) and transfer it to a high-pressure reaction kettle. Hydrothermally react at 130 °C for 18 h and then naturally cool to room temperature. After solid-liquid separation and washing and drying, obtain magnesium-aluminum hydrotalcite;

[0063] D1. Add the magnesium-aluminum hydrotalcite to a nitrogen-containing silane solution (the mass ratio of KH-540 to magnesium-aluminum hydrotalcite is 0.1:1) at a solid-liquid ratio of 0.08 g / mL, stir in a water bath environment at 45 °C at a rotation speed of 200 rpm and apply ultrasonic treatment at 10 kHz for 10 min, then let it stand for 30 min. After suction filtration separation and washing the precipitate, dry it in a hot air drying oven at 70 °C until constant weight to obtain the precursor;

[0064] D2. Add the precursor to a nitrogen-containing organic solution (the mass ratio of the intermediate to melamine is 1:0.15) at a solid-liquid ratio of 0.08 g / mL, and perform ultrasonic treatment at a frequency of 20 kHz for 20 min in a water bath environment at 50 °C, then let it stand for 10 min. Repeat the ultrasonic treatment and standing process 3 times (for a total of 1.5 h), then perform solid-liquid separation and wash the precipitate with absolute ethanol. After drying it in a vacuum drying oven at 50 °C until constant weight, place it in a tubular furnace and sinter and solidify it in a nitrogen atmosphere at 350 °C, and then crush it to obtain the modified magnesium-aluminum hydrotalcite.

[0065] Preparation Example 4

[0066] This Preparation Example 4 provides a method for preparing magnesium-aluminum hydrotalcite, including the following steps:

[0067] D0. Mix magnesium nitrate and aluminum nitrate at a molar ratio of 3:1 and dissolve them in deionized water to obtain a mixed metal solution. Mix the mixed metal solution with an alkali solution (the molar ratio of sodium hydroxide to sodium carbonate is 1:1) and transfer it to a high-pressure reaction kettle. Hydrothermally react at 130 °C for 18 h and then naturally cool to room temperature. After solid-liquid separation and washing and drying, obtain magnesium-aluminum hydrotalcite.

[0068] Example 1

[0069] Example 1 provides a preparation method of a novel PVC stabilizer, which includes: kneading 10 parts of the modified magnesium-aluminum hydrotalcite prepared in Preparation Example 1, 2 parts of calcium stearate, and 2 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0070] Example 2

[0071] Example 2 provides a preparation method of a novel PVC stabilizer, which includes: kneading 15 parts of the modified magnesium-aluminum hydrotalcite prepared in Preparation Example 1, 3 parts of calcium stearate, and 3 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0072] Example 3

[0073] Example 3 provides a preparation method of a novel PVC stabilizer, which includes: kneading 12 parts of the modified magnesium-aluminum hydrotalcite prepared in Preparation Example 1, 2.5 parts of calcium stearate, and 2.5 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0074] Comparative Example 1

[0075] Comparative Example 1 provides a preparation method of a novel PVC stabilizer, which includes: kneading 12 parts of the modified magnesium-aluminum hydrotalcite prepared in Preparation Example 2, 2.5 parts of calcium stearate, and 2.5 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0076] Comparative Example 2

[0077] Comparative Example 2 provides a preparation method of a novel PVC stabilizer, which includes: kneading 12 parts of the modified magnesium-aluminum hydrotalcite prepared in Preparation Example 3, 2.5 parts of calcium stearate, and 2.5 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0078] Comparative Example 3

[0079] Comparative Example 3 provides a preparation method of a novel PVC stabilizer, which includes: kneading 12 parts of the magnesium-aluminum hydrotalcite prepared in Preparation Example 4, 2.5 parts of calcium stearate, and 2.5 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0080] Comparative Example 4

[0081] Comparative Example 4 provides a preparation method of a novel PVC stabilizer, which includes: kneading 2.5 parts of calcium stearate and 2.5 parts of zinc stearate in a kneader to obtain the PVC stabilizer.

[0082] Performance Testing

[0083] 9 parts by mass of the PVC stabilizers prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were respectively mixed with 100 parts by mass of polyvinyl chloride resin, 40 parts by mass of plasticizer TOTM, 5 parts by mass of flame retardant (magnesium hydroxide), 0.5 part by mass of antioxidant 1010, 0.3 part by mass of ultraviolet absorber UV5411, and 0.3 part by mass of lubricant (paraffin) to prepare cable sheath materials, and the following items were tested.

[0084] Based on the standards described in GB / T2951, the cable sheath materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were tested for their original mechanical properties, and their tensile strength and elongation at break were recorded as shown in Table 1 below; the cable sheath materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were placed in a hot air flow environment at 158 °C for 168 h and then cooled to room temperature, and their mechanical property changes were tested and their tensile strength and elongation at break were recorded as shown in Table 1 below.

[0085] Based on GB / T2917.1-2002 "Determination of hydrogen chloride and any other acidic products evolved at high temperatures from blends and articles based on vinyl chloride homopolymers and copolymers - Congo red method", the cable sheath materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were made into specimens, and a color change experiment was carried out on Congo red test paper at 200 °C, and the time when Congo red completely turned blue was recorded (the experiment was repeated three times and the average value was taken), as shown in Table 2 below.

[0086] Table 1 Performance test data

[0087]

[0088]

[0089] Table 2 Congo red color change time

[0090]

[0091] As can be seen from Table 1 and Table 2, the cable sheath materials in Examples 1 to 3 provided by the present invention have good thermal stability, and the change in mechanical strength before and after the long-term heat experiment is relatively low. However, in Comparative Examples 1 and 2, due to the differences in the structures of the added modified magnesium-aluminum stabilizers, their long-term thermal stability is poor.

[0092] Although the embodiments of the present invention have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to these embodiments. However, it should be understood that such modifications and changes are all within the scope and spirit of the present invention described in the claims. Moreover, the present invention described herein can have other embodiments and can be implemented or realized in various ways.

Claims

1. A novel PVC stabilizer, characterized in that: The invention comprises, by mass, 10-15 parts of modified magnesium aluminum hydrotalcite, 2-3 parts of calcium stearate and 2-3 parts of zinc stearate; the modified magnesium aluminum hydrotalcite comprises a magnesium aluminum hydrotalcite matrix and a phosphate modified layer grown on the surface of the magnesium aluminum hydrotalcite matrix, and the surface of the phosphate modified layer is coated with a nitrogen-containing carbon layer.

2. The stabilizer according to claim 1, characterized in that The preparation method of the modified magnesium aluminum hydrotalcite comprises the following steps: surface treating the magnesium aluminum hydrotalcite to obtain a precursor; subjecting the precursor to a solvent thermal reaction in a phosphorus-containing nitrate solution to obtain an intermediate; and stirring and mixing the intermediate in a nitrogen-containing organic solution, separating and calcining the intermediate to obtain the modified magnesium aluminum hydrotalcite.

3. The stabilizer according to claim 2, characterized in that When magnesium aluminum hydrotalcite is subjected to surface treatment to obtain a precursor, the preparation method of the magnesium aluminum hydrotalcite comprises: mixing and dissolving magnesium nitrate and aluminum nitrate to obtain a mixed metal solution; mixing the mixed metal solution with an alkaline solution, and then hydrothermally reacting the mixed metal solution at 100°C-200°C to obtain magnesium aluminum hydrotalcite; wherein: the molar ratio of the magnesium nitrate to the aluminum nitrate is (2-4):1; and / or the alkaline solution comprises a sodium hydroxide solution; and / or the particle size of the magnesium aluminum hydrotalcite is 1 μm-20 μm.

4. The stabilizer according to claim 2, characterized in that When the magnesium aluminum hydrotalcite is surface treated to obtain a precursor, the magnesium aluminum hydrotalcite is stirred and reacted in a nitrogen-containing silane solution, and then separated and dried; wherein the nitrogen-containing silane solute in the nitrogen-containing silane solution includes one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane; and / or, the mass ratio of the magnesium aluminum hydrotalcite to the nitrogen-containing silane solute in the nitrogen-containing silane solution is 1:(0.1-0.15); and / or, the magnesium aluminum hydrotalcite is stirred and reacted in a nitrogen-containing silane solution at 40° C.-45° C.

5. The stabilizer according to claim 2, characterized in that When a precursor is subjected to a solvothermal reaction in a phosphorus-containing nitrate solution to obtain an intermediate, the method comprises: the phosphorus-containing solute in the phosphorus-containing nitrate solution is one of sodium phosphate, sodium hydrogen phosphate, and sodium dihydrogen phosphate; and / or the nitrate solute in the phosphorus-containing nitrate solution comprises one of rare earth nitrate and lithium nitrate; and / or the molar ratio of phosphorus in the phosphorus-containing solute to nitrate solute in the phosphorus-containing nitrate solution is 1:(0.2-0.3).

6. The stabilizer according to claim 2, characterized in that When the intermediate is stirred and mixed in the nitrogen-containing organic solution, it includes: the nitrogen-containing organic solute in the nitrogen-containing organic solution includes one of melamine and polyacrylamide; and / or the mass ratio of the intermediate to the nitrogen-containing organic solute in the nitrogen-containing organic solution is 1:(0.1-0.2).

7. The stabilizer according to claim 2, characterized in that After the intermediate is stirred and mixed in a nitrogen-containing organic solution, the solid-liquid separation is carried out and the modified magnesium-aluminum hydrotalcite is obtained by sintering and solidifying in a nitrogen-containing atmosphere at 300° C.-400° C.; wherein the solid-liquid separation includes filtration or suction filtration; and / or the nitrogen-containing atmosphere includes nitrogen or ammonia.

8. A method for preparing the stabilizer according to any one of claims 1 to 7, characterized in that: include: The stabilizer is prepared by stirring and kneading modified magnesium aluminum hydrotalcite, calcium stearate and zinc stearate.

9. Use of the stabilizer according to any one of claims 1 to 7 in automotive cables.

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