Compounding method of PVC (polyvinyl chloride) environment-friendly stabilizer

Abstract

The invention belongs to the technical field of PVC auxiliaries, and particularly relates to a compounding method of a PVC environment-friendly stabilizer, which comprises the following steps: cleaning expanded vermiculite, sequentially depositing titanium dioxide and calcium-zinc ions, then obtaining calcium-zinc stearate modified expanded vermiculite through a spraying reaction of sodium stearate, and finally mixing with an antioxidant, a lubricant, an auxiliary stabilizer and an ultraviolet absorbent to obtain the PVC environment-friendly stabilizer. The PVC environment-friendly stabilizer is obtained. The defects of an existing stabilizer are overcome, the porous structure of expanded vermiculite is used as a frame, zinc stearate and calcium stearate are fixed to the surface in an in-situ fixing mode, and the zinc stearate and calcium stearate composite stabilizer has the advantages of being not prone to precipitation and good in stabilizing effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of PVC additives, and particularly relates to a compounding method of an environment-friendly PVC stabilizer. Background Art

[0002] Polyvinyl chloride is one of the five major general-purpose plastics in the world, with advantages such as high strength, low price, good chemical corrosion resistance, good electrical insulation, and flame retardancy. However, under high-temperature and high-shear processing conditions of polyvinyl chloride, polyvinyl chloride is extremely easy to remove hydrogen chloride on the molecular chain, resulting in polymer degradation, product deterioration, mechanical property decline, and even a significant shortening of service life. Therefore, stabilizers need to be added during the polyvinyl chloride processing to ensure the stability of polyvinyl chloride products.

[0003] During the PVC processing, heat stabilizers generally adopt lead salt stabilizers, organotin stabilizers, and calcium-zinc stabilizers. Among them, lead salt stabilizers and organotin stabilizers have problems such as high toxicity and high price. Calcium-zinc stabilizers have attracted much attention due to their environmental protection, non-toxic, and high-efficiency characteristics. However, imported calcium-zinc stabilizers are relatively expensive, and domestic calcium-zinc stabilizers contain diketone compounds, which have the potential risk of PVC discoloration. Therefore, calcium-zinc stabilizers are difficult to be widely used. Summary of the Invention

[0004] Aiming at the problems in the prior art, the present invention provides a compounding method of an environment-friendly PVC stabilizer, which solves the defects of the existing stabilizers, uses the porous structure of expanded vermiculite as a framework, and fixes zinc stearate and calcium stearate on the surface in an in-situ fixing manner, having the characteristics of not being easy to precipitate and good stabilizing effect.

[0005] To achieve the above technical objectives, the technical solution of the present invention is as follows: A compounding method of an environment-friendly PVC stabilizer, comprising the following steps: Step 1: Put expanded vermiculite into the ethanol-ether mixture and ultrasonicate for 1 - 2 h. Then add water, seal it and carry out reflux treatment for 3 - 5 h. After filtration, dry it to obtain clean expanded vermiculite. The concentration of expanded vermiculite in the ethanol-ether mixture is 200 - 500 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 60 - 70%. The temperature of ultrasonication is 5 - 10 °C, and the ultrasonic frequency is 70 - 90 kHz. The amount of water added is 20 - 30% of the volume of the mixture. The temperature of the sealed reflux is 50 - 60 °C, and the reflux gas is directly introduced into the mixture. The drying is carried out by hot air drying, and the drying temperature is 130 - 150 °C. This step uses the washing property of the ethanol-ether mixture and the high-frequency vibration of ultrasonication to completely remove the impurities on the surface of expanded vermiculite and perform a certain washing on the porous pores. With the addition of water and the sealed reflux treatment, ether is converted into steam and re-enters the solvent, forming a gas expansion and blasting effect to further clean the pores after the vermiculite absorbs water and expands, thus ensuring the complete washing inside and outside the expanded vermiculite and obtaining clean expanded vermiculite. Step 2: Add titanium chloride to ethanol and stir evenly to obtain a titanium alcohol solution. Then put the clean expanded vermiculite into the titanium alcohol solution and ultrasonicate for 20 - 30 min. After filtration, let it stand for 1 - 3 h to obtain titanium-oxygen adsorbed expanded vermiculite. The concentration of titanium chloride in the titanium alcohol solution is 50 - 80 g / L, the stirring speed is 300 - 500 r / min, the concentration of expanded vermiculite in the titanium alcohol solution is 300 - 500 g / L, the ultrasonic frequency is 70 - 90 kHz, and the temperature is 5 - 10 °C. The atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 5:1, and the temperature is 270 - 300 °C. This step uses the solubility of titanium chloride in ethanol and combines with the adsorption property of expanded vermiculite to form a liquid film on the inner and outer surfaces of expanded vermiculite. After drying and in-situ hydrolysis and polycondensation, titanium dioxide modified expanded vermiculite is obtained. Based on the fact that the concentration of titanium chloride is much lower than that of expanded vermiculite, and titanium chloride is adsorbed on the surface of expanded vermiculite by liquid-phase deposition, so titanium dioxide is sporadically adsorbed on expanded vermiculite, forming a homogeneous distribution structure, and at the same time ensuring that expanded vermiculite still contains a large number of exposed silanol groups and aluminol groups. Step 3: Add tetrabutyl titanate, calcium chloride and zinc chloride into ethanol and stir evenly. Then put the titanium-oxygen adsorbed expanded vermiculite into it and perform ultrasonic treatment for 20 - 30 min. After filtration, let it stand for 20 - 30 min, and then sinter to obtain calcium-zinc modified expanded vermiculite. The mass ratio of tetrabutyl titanate, calcium chloride and zinc chloride is 1:2 - 4:4 - 6. The concentration of tetrabutyl titanate in ethanol is 50 - 80 g / L, the stirring speed for even stirring is 300 - 500 r / min, the concentration of the titanium-oxygen adsorbed expanded vermiculite is 100 - 300 g / L, the temperature for ultrasonic treatment is 5 - 10 °C, the ultrasonic frequency is 60 - 80 kHz. The atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the temperature is 100 - 120 °C; the sintering temperature is 250 - 280 °C. This step utilizes the solubility of ethanol to homogeneously disperse tetrabutyl titanate, calcium chloride and zinc chloride. During the ultrasonic treatment and the adsorption process of expanded vermiculite, a liquid film is ensured to form on the surface of expanded vermiculite, and tetrabutyl titanate, as an intercalator and fixative, is located around calcium and zinc. Through constant-temperature hydrolysis and sintering, calcium and zinc are deposited on the surface of expanded vermiculite. Among them, titanium dioxide, as a modifier and dopant, not only forms an intercalation around calcium and zinc to achieve the effect of fixing metal ions, but also can improve the surface conduction of heat and electrons. Step 4: Add sodium stearate into hot water and stir evenly, then spray it on the calcium-zinc modified expanded vermiculite. After drying, let it stand and react for 2 - 5 h, and repeat this process 2 - 5 times to obtain calcium-zinc stearate modified expanded vermiculite. The concentration of sodium stearate in hot water is 200 - 400 g / L, the temperature is 70 - 80 °C, the stirring speed is 300 - 500 r / min, and the spraying speed is 3 - 5 mL / cm 2 , and the drying temperature is 110 - 120 °C. This step utilizes the solubility of sodium stearate in hot water and the in-situ reaction after spraying to ensure the in-situ reaction between sodium stearate and calcium chloride and zinc chloride, realizing the in-situ chelation reaction on the surface of expanded vermiculite to obtain zinc stearate and calcium stearate. Step 5: Blend and process an antioxidant, a lubricant, a co-stabilizer, an ultraviolet absorber and the calcium-zinc stearate modified expanded vermiculite, and stir at a constant temperature for 20 - 30 min to obtain a PVC environmental stabilizer. The mass ratio of the PVC environmental stabilizer is: 1 - 3 parts of antioxidant, 5 - 8 parts of lubricant, 1 - 4 parts of co-stabilizer, 1 - 5 parts of ultraviolet absorber, and 80 - 90 parts of calcium-zinc stearate modified expanded vermiculite. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the co-stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone, the temperature for constant-temperature stirring is 30 - 50 °C, and the stirring speed is 300 - 500 r / min.

[0006] As can be seen from the above description, the present invention has the following advantages: 1. The present invention solves the defects of the existing stabilizers. By using the porous structure of expanded vermiculite as a framework and fixing zinc stearate and calcium stearate on the surface in an in-situ fixing manner, it has the characteristics of being not easily precipitated and having a good stabilizing effect.

[0007] 2. By utilizing the stability, heat conductivity and electrical conductivity of titanium dioxide, the present invention can form a certain range of heat sharing, improve the thermal stability. At the same time, by utilizing the enrichment effect of titanium dioxide on hydrogen chloride, the influence of free radicals in polyvinyl chloride is effectively alleviated, and the service life of calcium stearate and zinc stearate is extended. Specific Embodiments

[0008] The present invention will be described in detail in combination with embodiments, but no limitation is made to the claims of the present invention. Embodiment 1

[0009] A composite method of a PVC environmental protection stabilizer includes the following steps: Step 1: Put expanded vermiculite into an ethanol-ether mixture and ultrasonicate for 1 h, then add water for sealed reflux treatment for 3 h. After filtration, it is dried to obtain clean expanded vermiculite. The concentration of expanded vermiculite in the ethanol-ether mixture is 500 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 70%. The temperature of the ultrasonication is 5°C, and the ultrasonic frequency is 70 kHz. The amount of water added is 30% of the volume of the mixture. The temperature of the sealed reflux is 50°C, and the reflux gas is directly introduced into the mixture. The drying is carried out by hot air drying, and the drying temperature is 130°C. Step 2: Add titanium chloride to ethanol and stir evenly to obtain a titanium alcohol solution. Then put the clean expanded vermiculite into the titanium alcohol solution and ultrasonicate for 20 min. After filtration, it is left standing for 1 h to obtain titanium-oxygen adsorbed expanded vermiculite. The concentration of titanium chloride in the titanium alcohol solution is 80 g / L, and the stirring speed is 300 r / min. The concentration of expanded vermiculite in the titanium alcohol solution is 500 g / L. The ultrasonic frequency is 70 kHz, and the temperature is 5°C. The atmosphere of the standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 5:1, and the temperature is 270°C. Step 3: Add tetrabutyl titanate, calcium chloride, and zinc chloride into ethanol and stir evenly. Then put the titanium-oxygen adsorbed expanded vermiculite into it and perform ultrasonic treatment for 20 min. After filtration, let it stand for 20 min, and sinter to obtain calcium-zinc modified expanded vermiculite. The mass ratio of tetrabutyl titanate, calcium chloride, and zinc chloride is 1:4:6. The concentration of tetrabutyl titanate in ethanol is 80 g / L, the stirring speed for even stirring is 300 r / min, the concentration of the titanium-oxygen adsorbed expanded vermiculite is 300 g / L, the temperature for ultrasonic treatment is 5 °C, the ultrasonic frequency is 60 kHz, the atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the temperature is 100 °C; the sintering temperature is 250 °C; Step 4: Add sodium stearate into hot water and stir evenly, then spray it on the calcium-zinc modified expanded vermiculite. After drying, let it stand and react for 2 h, and repeat 2 times to obtain calcium-zinc stearate modified expanded vermiculite. The concentration of sodium stearate in hot water is 400 g / L, the temperature is 70 °C, the stirring speed is 300 r / min, and the spraying speed is 5 mL / cm 2 , and the drying temperature is 110 °C; Step 5: Blend the antioxidant, lubricant, auxiliary stabilizer, ultraviolet absorber with the calcium-zinc stearate modified expanded vermiculite and stir at a constant temperature for 20 min to obtain the PVC environmental protection stabilizer. The mass ratio of the PVC environmental protection stabilizer is: 3 parts of antioxidant, 8 parts of lubricant, 4 parts of auxiliary stabilizer, 5 parts of ultraviolet absorber, and 90 parts of calcium-zinc stearate modified expanded vermiculite. The antioxidant uses β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl alcohol ester, the lubricant uses polyethylene wax, the auxiliary stabilizer uses epoxy soybean oil, the ultraviolet absorber uses 2-hydroxy-4-n-octyloxybenzophenone, the temperature for constant temperature stirring is 30 °C, and the stirring speed is 300 r / min. Example 2

[0010] A compounding method of a PVC environmental protection stabilizer, comprising the following steps: Step 1: Put expanded vermiculite into an ethanol-ether mixture and perform ultrasonic treatment for 2 h. Then add water and perform sealed reflux treatment for 5 h. After filtration, dry it to obtain clean expanded vermiculite. The concentration of expanded vermiculite in the ethanol-ether mixture is 200 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 60%. The temperature for ultrasonic treatment is 10 °C, and the ultrasonic frequency is 90 kHz; the addition amount of water is 30% of the volume of the mixture. The temperature for sealed reflux is 50 °C, and the reflux gas is directly introduced into the mixture. The drying uses hot air drying, and the drying temperature is 150 °C; Step 2: Add titanium chloride into ethanol and stir evenly to obtain a titanium alcohol solution. Then, put the clean expanded vermiculite into the titanium alcohol solution and ultrasonicate for 30 min. After filtration, let it stand for 3 h to obtain titanium-oxygen adsorbed expanded vermiculite. The concentration of titanium chloride in the titanium alcohol solution is 50 g / L, the stirring speed is 500 r / min, the concentration of the expanded vermiculite in the titanium alcohol solution is 300 g / L, the frequency of the ultrasonication is 90 kHz, and the temperature is 10°C. The atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 5:1, and the temperature is 300°C; Step 3: Add tetrabutyl titanate, calcium chloride, and zinc chloride into ethanol and stir evenly. Then, put the titanium-oxygen adsorbed expanded vermiculite into it and ultrasonicate for 30 min. After filtration, let it stand for 30 min and sinter to obtain calcium-zinc modified expanded vermiculite. The mass ratio of tetrabutyl titanate, calcium chloride, and zinc chloride is 1:2:4. The concentration of tetrabutyl titanate in ethanol is 50 g / L, the stirring speed for even stirring is 500 r / min, the concentration of the titanium-oxygen adsorbed expanded vermiculite is 100 g / L, the temperature for ultrasonication is 10°C, the ultrasonic frequency is 60 - 80 kHz, the atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the temperature is 120°C; the sintering temperature is 280°C; Step 4: Add sodium stearate into hot water and stir evenly, then spray it on the calcium-zinc modified expanded vermiculite. After drying, let it stand and react for 5 h, and repeat this process 5 times to obtain calcium-zinc stearate modified expanded vermiculite. The concentration of sodium stearate in hot water is 200 g / L, the temperature is 80°C, the stirring speed is 500 r / min, and the spraying speed is 3 mL / cm 2 , and the drying temperature is 120°C; Step 5: Blend the antioxidant, lubricant, auxiliary stabilizer, ultraviolet absorber with the calcium-zinc stearate modified expanded vermiculite and stir at a constant temperature for 30 min to obtain a PVC environmental protection stabilizer. The mass ratio of the PVC environmental protection stabilizer is: 1 part of antioxidant, 5 parts of lubricant, 1 part of auxiliary stabilizer, 1 part of ultraviolet absorber, and 80 parts of calcium-zinc stearate modified expanded vermiculite. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone, the temperature for stirring at a constant temperature is 50°C, and the stirring speed is 500 r / min. Example 3

[0011] A compounding method of a PVC environmental protection stabilizer, comprising the following steps: Step 1: Put expanded vermiculite into the ethanol-ether mixture and ultrasonicate for 2 h. Then add water, seal and reflux for 4 h. After filtration, dry it to obtain clean expanded vermiculite. The concentration of expanded vermiculite in the ethanol-ether mixture is 400 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 65%. The temperature of ultrasonication is 8°C, and the ultrasonic frequency is 80 kHz. The amount of water added is 25% of the volume of the mixture. The temperature of the sealed reflux is 55°C, and the reflux gas is directly introduced into the mixture. The drying is carried out by hot air drying, and the drying temperature is 140°C. Step 2: Add titanium chloride to ethanol and stir evenly to obtain a titanium alcohol solution. Then put the clean expanded vermiculite into the titanium alcohol solution and ultrasonicate for 25 min. After filtration, let it stand for 2 h to obtain titanium-oxygen adsorbed expanded vermiculite. The concentration of titanium chloride in the titanium alcohol solution is 70 g / L, and the stirring speed is 400 r / min. The concentration of expanded vermiculite in the titanium alcohol solution is 400 g / L. The ultrasonic frequency is 80 kHz, and the temperature is 8°C. The atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 5:1, and the temperature is 280°C. Step 3: Add tetrabutyl titanate, calcium chloride and zinc chloride to ethanol and stir evenly. Then put the titanium-oxygen adsorbed expanded vermiculite into it and ultrasonicate for 25 min. After filtration, let it stand for 25 min and sinter to obtain calcium-zinc modified expanded vermiculite. The mass ratio of tetrabutyl titanate, calcium chloride and zinc chloride is 1:3:5. The concentration of tetrabutyl titanate in ethanol is 70 g / L, and the stirring speed for even stirring is 400 r / min. The concentration of titanium-oxygen adsorbed expanded vermiculite is 200 g / L. The temperature of ultrasonication is 8°C, and the ultrasonic frequency is 70 kHz. The atmosphere for standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the temperature is 110°C. The sintering temperature is 270°C. Step 4: Add sodium stearate to hot water and stir evenly, then spray it on the calcium-zinc modified expanded vermiculite. After drying, let it stand and react for 4 h, and repeat 4 times to obtain calcium-zinc stearate modified expanded vermiculite. The concentration of sodium stearate in hot water is 300 g / L, the temperature is 75°C, and the stirring speed is 400 r / min. The spraying speed is 4 mL / cm 2 , and the drying temperature is 115°C. Step 5, blend the antioxidant, lubricant, auxiliary stabilizer, ultraviolet absorber with calcium zinc stearate modified expanded vermiculite, and stir at a constant temperature for 25 min to obtain the PVC environmental-friendly stabilizer. The mass ratio of the PVC environmental-friendly stabilizer is as follows: 2 parts of antioxidant, 7 parts of lubricant, 3 parts of auxiliary stabilizer, 4 parts of ultraviolet absorber, and 85 parts of calcium zinc stearate modified expanded vermiculite. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone. The temperature of the constant-temperature stirring is 40 °C, and the stirring speed is 400 r / min.

[0012] Comparative Example 1 A compounding method of a PVC environmental-friendly stabilizer includes the following steps: Step 1, put the expanded vermiculite into the ethanol-ether mixture and ultrasonicate for 2 h, then add water for sealed reflux treatment for 4 h, filter and dry to obtain clean expanded vermiculite. The concentration of the expanded vermiculite in the ethanol-ether mixture is 400 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 65%. The temperature of the ultrasonication is 8 °C, and the ultrasonic frequency is 80 kHz. The addition amount of water is 25% of the volume of the mixture. The temperature of the sealed reflux is 55 °C, and the reflux gas is directly introduced into the mixture. The drying is carried out by hot air drying, and the drying temperature is 140 °C. Step 2, add calcium chloride and zinc chloride to ethanol and stir evenly, then put the titanium-oxygen adsorbed expanded vermiculite and ultrasonicate for 25 min, filter and let stand for 25 min to obtain calcium zinc modified expanded vermiculite. The mass ratio of calcium chloride and zinc chloride is 3:5. The concentration of calcium chloride in ethanol is 210 g / L, the stirring speed of the even stirring is 400 r / min, the concentration of the titanium-oxygen adsorbed expanded vermiculite is 200 g / L, the temperature of the ultrasonication is 8 °C, the ultrasonic frequency is 70 kHz, and the temperature of the standing is 110 °C. Step 3, add sodium stearate to hot water and stir evenly, then spray it on the calcium zinc modified expanded vermiculite, dry and let stand for reaction for 4 h, repeat 4 times to obtain calcium zinc stearate modified expanded vermiculite. The concentration of sodium stearate in hot water is 300 g / L, the temperature is 75 °C, the stirring speed is 400 r / min, the spraying speed is 4 mL / cm 2 , and the drying temperature is 115 °C; Step 4: Blend and process the antioxidant, lubricant, auxiliary stabilizer, ultraviolet absorber and calcium zinc stearate modified expanded vermiculite, and stir at a constant temperature for 25 min to obtain the PVC environmental protection stabilizer. The mass ratio of the PVC environmental protection stabilizer is as follows: 2 parts of antioxidant, 7 parts of lubricant, 3 parts of auxiliary stabilizer, 4 parts of ultraviolet absorber, and 85 parts of calcium zinc stearate modified expanded vermiculite. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone, the temperature of the constant temperature stirring is 40 °C, and the stirring speed is 400 r / min.

[0013] Comparative Example 2 A compounding method for a PVC environmental protection stabilizer includes: blending and processing an antioxidant, a lubricant, an auxiliary stabilizer, an ultraviolet absorber, zinc stearate and calcium stearate, and stirring at a constant temperature for 25 min to obtain the PVC environmental protection stabilizer. The mass ratio of the PVC environmental protection stabilizer is as follows: 2 parts of antioxidant, 7 parts of lubricant, 3 parts of auxiliary stabilizer, 4 parts of ultraviolet absorber, 53 parts of zinc stearate, and 32 parts of calcium stearate. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone, the temperature of the constant temperature stirring is 40 °C, and the stirring speed is 400 r / min.

[0014] Comparative Example 3 A compounding method for a PVC environmental protection stabilizer includes: blending and processing vermiculite, nano-titanium dioxide, an antioxidant, a lubricant, an auxiliary stabilizer, an ultraviolet absorber, zinc stearate and calcium stearate, and stirring at a constant temperature for 25 min to obtain the PVC environmental protection stabilizer. The mass ratio of the PVC environmental protection stabilizer is as follows: 7 parts of vermiculite, 4 parts of nano-titanium dioxide, 2 parts of antioxidant, 7 parts of lubricant, 3 parts of auxiliary stabilizer, 4 parts of ultraviolet absorber, 42 parts of zinc stearate, and 32 parts of calcium stearate. The antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxy soybean oil, the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone, the temperature of the constant temperature stirring is 40 °C, and the stirring speed is 400 r / min.

[0015] Performance testing Using the samples of Examples 1-3 and Comparative Examples 1-3 as test samples, performance testing was carried out, and the results are as follows: The test methods include: Hot oven method: Put the test sample into a hot oven at 150 °C and observe the color after heating for 120 min.

[0016] Congo red method: According to the content of GB / T2917-2002, cut the PVC material prepared based on the test sample into small squares with a side length of 2 cm, put them into a reaction test tube with a height of 50 mm, and vibrate slightly. Place the Congo red test paper 2 cm above the sample particles, and tighten the stopper. Place the test tube in an oil bath at the temperature required for the specific test, observe and record the time when the test paper changes from red to blue (pH = 3), and the result corresponds to the initial coloring property.

[0017]

[0018] The above test data show that the thermal stability time of the PVC environmental stabilizer prepared in Examples 1-3 is significantly better than that of Comparative Example 1 and Comparative Example 2, and Comparative Example 1 is better than Comparative Example 2, indicating that the environmental stabilizer prepared by the in-situ fixation system of calcium stearate and zinc stearate with expanded vermiculite as the framework and titanium dioxide as the dopant has good thermal stability, and the structure of vermiculite and the loading and doping of nano-titanium dioxide can effectively improve the stability and service life of calcium stearate and zinc stearate, reducing problems such as precipitation. At the same time, by comparing Comparative Example 3 with Example 3, it can be seen that the vermiculite-titanium dioxide in the technical solution forms a calcium stearate and zinc stearate fixed structure, which can effectively improve the stability and service life of zinc stearate and calcium stearate.

[0019] It can be understood that the above specific description of the present invention is only for explaining the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effect; as long as it meets the usage requirements, it is within the protection scope of the present invention.

Claims

1. A compounding method of an environment-friendly PVC stabilizer, characterized in that: It includes the following steps: Step 1: Put expanded vermiculite into the ethanol-ether mixture and ultrasonicate for 1 - 2 h, then add water, seal and reflux for 3 - 5 h, filter and dry to obtain clean expanded vermiculite; Step 2: Add titanium chloride to ethanol and stir evenly to obtain a titanium alcohol solution, then put the clean expanded vermiculite into the titanium alcohol solution and ultrasonicate for 20 - 30 min, filter and let stand for 1 - 3 h to obtain titanium-oxygen adsorbed expanded vermiculite; Step 3: Add tetrabutyl titanate, calcium chloride and zinc chloride to ethanol and stir evenly, then put the titanium-oxygen adsorbed expanded vermiculite into it and ultrasonicate for 20 - 30 min, filter and let stand for 20 - 30 min, and sinter to obtain calcium-zinc modified expanded vermiculite; Step 4: Add sodium stearate to hot water and stir evenly, then spray it on the calcium-zinc modified expanded vermiculite, dry and let stand for reaction for 2 - 5 h, repeat 2 - 5 times to obtain calcium-zinc stearate modified expanded vermiculite; Step 5: Blend the antioxidant, lubricant, auxiliary stabilizer, ultraviolet absorber with the calcium-zinc stearate modified expanded vermiculite and stir at a constant temperature for 20 - 30 min to obtain a PVC environmental protection stabilizer.

2. The compounding method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The concentration of the expanded vermiculite in the ethanol-ether mixture in Step 1 is 200 - 500 g / L, and the volume ratio of ethanol in the ethanol-ether mixture is 60 - 70%. The temperature of the ultrasonication is 5 - 10 °C, and the ultrasonic frequency is 70 - 90 kHz.

3. The composite method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The addition amount of water in Step 1 is 20 - 30% of the volume of the mixture. The temperature of the sealed reflux is 50 - 60 °C, and the reflux gas is directly introduced into the mixture. The drying is carried out by hot air drying, and the drying temperature is 130 - 150 °C.

4. The composite method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The concentration of titanium chloride in the titanium alcohol solution in Step 2 is 50 - 80 g / L, the stirring speed is 300 - 500 r / min. The concentration of the expanded vermiculite in the titanium alcohol solution is 300 - 500 g / L. The ultrasonic frequency is 70 - 90 kHz, and the temperature is 5 - 10 °C. The atmosphere of the standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 5:1, and the temperature is 270 - 300 °C.

5. The composite method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The mass ratio of tetrabutyl titanate, calcium chloride and zinc chloride in Step 3 is 1:2 - 4:4 - 6. The concentration of tetrabutyl titanate in ethanol is 50 - 80 g / L, and the stirring speed for even stirring is 300 - 500 r / min.

6. The compounding method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The concentration of the titanium-oxygen adsorbed expanded vermiculite in Step 3 is 100 - 300 g / L. The temperature of the ultrasonication is 5 - 10 °C, and the ultrasonic frequency is 60 - 80 kHz. The atmosphere of the standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the temperature is 100 - 120 °C. The sintering temperature is 250 - 280 °C.

7. The compounding method of the PVC environmental protection stabilizer according to claim 1, characterized in that: The concentration of sodium stearate in hot water in Step 4 is 200 - 400 g / L, the temperature is 70 - 80 °C, the stirring speed is 300 - 500 r / min, and the spraying speed is 3 - 5 mL / cm 2 , and the drying temperature is 110 - 120 °C.

8. The composite method of the PVC environmental stabilizer according to claim 1, characterized in that: The mass ratio of the PVC environmental protection stabilizer in Step 5 is: 1 - 3 parts of antioxidant, 5 - 8 parts of lubricant, 1 - 4 parts of auxiliary stabilizer, 1 - 5 parts of ultraviolet absorber, 80 - 90 parts of calcium-zinc stearate modified expanded vermiculite. The temperature of the constant-temperature stirring is 30 - 50 °C, and the stirring speed is 300 - 500 r / min.

9. The compounding method of the PVC environmental protection stabilizer according to claim 8, characterized in that: The antioxidant is octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, the lubricant is polyethylene wax, the auxiliary stabilizer is epoxidized soybean oil, and the ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone.

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