Oil type PVC compound additive and its production method

Abstract

The present application relates to the technical field of PVC compound auxiliary agent, and discloses an oil type PVC compound auxiliary agent and a production method thereof.The compound auxiliary agent comprises 50-70 parts by weight of bio-based carrier oil, 10-25 parts by weight of sodium perchlorate-choline chloride-urea ternary deep eutectic solvent, 15-30 parts by weight of long-chain lipophilic graft modified zeolite and 0.5-2 parts by weight of antioxidant.The production method comprises the following steps: pre-dispersing the bio-based carrier oil and the modified zeolite by high shear; performing in-situ dehydration by ultrasonic cavitation under specific frequency and power density; adding the ternary deep eutectic solvent and the antioxidant to perform phase transfer complex mixing; finally, cooling and monitoring online rheology, and when the thixotropic index reaches 2.5-3.5, packaging.The present application combines the chemical multi-target point synergistic mechanism and the physical full-space anti-settling process, prolongs the thermal stabilization time of the PVC product, effectively prevents the secondary agglomeration of inorganic particles, and solves the industry problems of easy stratification and easy oil separation of the traditional suspension oil agent.

Description

Technical Field

[0001] This invention relates to the field of PVC compounding additives technology, specifically to an oil-based PVC compounding additive and its production method. Background Technology

[0002] Polyvinyl chloride (PVC) products are indispensable to the national economy and people's livelihood, and their application share is increasing year by year. This is due to their comprehensive advantages, including light weight, corrosion resistance, aesthetic appeal, ease of molding, and lower cost than metal materials. However, PVC itself has inherent defects: its aging cycle is short when exposed to strong light and heat, and its strength is insufficient due to the nature of the base material, resulting in either hard and brittle or soft and easily deformed properties. Therefore, adding modifiers to enhance specific properties has become an inevitable choice.

[0003] Currently, the industry commonly uses zeolite to adsorb trace amounts of HCl released during PVC degradation, combined with sodium perchlorate as an auxiliary stabilizer. These two single-component compounds are then added to PVC masterbatch for processing and molding. However, the existing technology has the following drawbacks: First, the two component manufacturers are not related and their independent production leads to overlapping processes and waste of resources. At the same time, the differences in particle size distribution and specific gravity caused by independent production make it easy for downstream companies to produce local proportion deviations and batch quality fluctuations after simple mechanical mixing.

[0004] Secondly, zeolite surfaces are rich in silanol groups, exhibiting strong hydrophilicity. They have poor compatibility with oily components such as PVC resin or plasticizers, and are prone to agglomeration and sedimentation. Sodium perchlorate exists in solid powder form, resulting in a small contact area in oily systems, making it difficult to fully utilize its thermal stability.

[0005] Third, traditional compounding processes involve multiple grinding and mixing steps, resulting in numerous dust pollution points during production. This not only affects the working environment but also makes it difficult to maintain stable quality in PVC products.

[0006] Therefore, developing a compound additive that can achieve microscopic uniform dispersion of zeolite and sodium perchlorate, while possessing excellent storage stability and thermal stability, is of great practical significance. Summary of the Invention

[0007] (a) Technical problems to be solved: To address the shortcomings of existing technologies, this invention provides an oil-based PVC compound additive and its production method, solving the problems of inorganic particles easily undergoing polar agglomeration, severe stratification, and oil separation during long-term static standing in oil-based suspension systems.

[0008] (II) Technical Solution: In a first aspect, the present invention provides an oil-based PVC compounding additive, comprising 50-70 parts by weight of bio-based carrier oil, 10-25 parts by weight of sodium perchlorate-choline chloride-urea ternary eutectic solvent, 15-30 parts by weight of long-chain lipophilic grafted modified zeolite, and 0.5-2 parts by weight of antioxidant.

[0009] The sodium perchlorate-choline chloride-urea ternary eutectic solvent is a room-temperature liquid complex formed by sodium perchlorate monohydrate and a hydrogen bond donor under heating conditions, through the disruption of lattice energy and the reconstruction of the three-dimensional intermolecular hydrogen bond network.

[0010] The long-chain oleophilic graft-modified zeolite is a hydrophobic and oleophilic zeolite obtained by chemically bonding the surface of a zeolite molecular sieve with a long-chain silane coupling agent containing hexadecyl in the presence of a grafting promoter, so that the surface is coated with long carbon chains.

[0011] As a preferred embodiment of the present invention, the antioxidant is one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0012] As a preferred embodiment of the present invention, the bio-based carrier oil is a cashew phenol-modified epoxy ester, and its preparation method includes the following steps: Cashew phenol was mixed with acetic anhydride and refluxed at 80-120℃ for 3-4 hours. The mixture was then distilled under reduced pressure to obtain a cashew phenol acetate intermediate. The temperature was then lowered to 50-60℃, and glacial acetic acid and a strong acid cation exchange resin were added. Under stirring, 27-30% hydrogen peroxide was slowly added dropwise. The mixture was heated to 65-70℃ and stirred for 4-5 hours. The mixture was filtered while hot to remove and recover the solid strong acid cation exchange resin catalyst. The filtrate was allowed to stand and separate into layers. The upper oil phase was washed 1-2 times with a 1-3% sodium carbonate aqueous solution, and then washed with hot deionized water until neutral. Finally, the neutral oil phase was dehydrated at 90-100℃ and a vacuum of -0.09 MPa for 2-3 hours, and then filtered to obtain a cashew phenol-modified epoxy ester.

[0013] As a preferred technical solution of the present invention, the mass ratio of cashew phenol, acetic anhydride, glacial acetic acid, strong acidic cation exchange resin and hydrogen peroxide with a mass fraction of 27-30% is 100:(35-50):(15-25):(5-10):(60-80).

[0014] As a preferred embodiment of the present invention, the preparation method of the sodium perchlorate-choline chloride-urea ternary eutectic solvent includes the following steps: Choline chloride and urea, dried to constant weight under vacuum at 60-80℃, are mixed and heated to 70-80℃ to initially eutecticly form a translucent paste. Then, under constant temperature stirring, sodium perchlorate monohydrate is slowly added, controlling the exothermic reaction system until the solid completely dissolves to form a homogeneous transparent liquid. After degassing under vacuum at -0.08MPa to -0.1MPa, the mixture is cooled to room temperature to obtain a ternary deep eutectic solvent of sodium perchlorate-choline chloride-urea.

[0015] As a preferred technical solution of the present invention, the mass ratio of choline chloride, urea and sodium perchlorate monohydrate is 100:(80-90):(20-40).

[0016] As a preferred embodiment of the present invention, the preparation process of long-chain lipophilic grafted modified zeolite is as follows: Zeolite powder was added to ethanol and ultrasonically treated for 20-40 min to obtain a zeolite powder-ethanol suspension. Hexadecyltrimethoxysilane was added to an acidic water-ethanol mixed solvent and ultrasonically treated for 30-60 min. It was then slowly added dropwise to the zeolite powder-ethanol suspension. Piperazine pyrophosphate was added, and the mixture was refluxed and stirred at 70-80℃ for 2-4 h. The mixture was washed, dried, and pulverized by airflow to a particle size D90≤5μm to obtain long-chain oleophilic grafted modified zeolite.

[0017] As a preferred embodiment of the present invention, the mass ratio of zeolite powder, ethanol, hexadecyltrimethoxysilane, acidic water-ethanol mixed solvent, and piperazine pyrophosphate is 100:(400-600):(5-15):(30-50):(10-25); wherein, the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:(4-9), and the pH value is adjusted to 4.0-5.5 with glacial acetic acid.

[0018] Secondly, the present invention also provides a method for producing an oil-based PVC compounding additive, the method comprising the following steps: S1. Pre-dispersion: The bio-based carrier oil is pumped into a reactor equipped with a high-shear dispersion device and a vacuum system. Stirring is started, and long-chain oleophilic grafted modified zeolite is added at a uniform speed. High-shear dispersion is carried out at a speed of 2500-3000 r / min for 15-20 min to obtain a primary suspension oil.

[0019] S2. In-situ dehydration via ultrasonic cavitation: Raise the temperature of the primary suspended oil to 75-85℃, start the ultrasonic generator, and control the ultrasonic frequency of the ultrasonic generator to 20-25kHz and the power density to 0.3-0.5W / cm³. 3 At the same time, turn on the vacuum pump to make the vacuum inside the vessel reach -0.08MPa to -0.095MPa and maintain it for 30-45 minutes.

[0020] S3. Phase transfer complexation mixing: Remove the vacuum and slowly add sodium perchlorate-choline chloride-urea ternary eutectic solvent and antioxidant to the reactor under stirring. Adjust the stirring speed to 500-800 r / min and continue mixing at a constant temperature for 20-30 min to form a microemulsion liquid composite system.

[0021] S4. Rheological monitoring and packaging: Stop heating and introduce circulating water to cool the microemulsion liquid composite system to below 40°C. Use an online rheometer to monitor the fluid state. When the system reaches the target thixotropic index of 2.5-3.5, it indicates that a stable spatial network anti-settling structure has been formed inside the system. At this time, transfer it to the finished product storage tank for metering and packaging to obtain the oil-based PVC compound additive.

[0022] (III) Beneficial technical effects: 1. This invention constructs a multi-target synergistic thermal stabilization mechanism, significantly extending the thermal stability time of PVC. This invention overcomes the limitations of single additives; the synthesized cashew phenol-modified epoxy ester serves as both a carrier oil and utilizes its unique benzene ring rigidity and epoxy groups to actively and efficiently capture free hydrogen chloride (HCl) through ring-opening. Simultaneously, it innovatively employs deep eutectic solvation technology to convert traditional solid sodium perchlorate into a room-temperature liquid complex, solving the problem of small contact area for inorganic salt powders in the oil phase, achieving uniform dispersion and blocking of hydrogen chloride dechlorination. Combined with the synergistic effect of a grafting accelerator (piperazine pyrophosphate) and antioxidants, a robust anti-degradation barrier is successfully constructed, significantly improving the initial colorability and long-term thermal stability of PVC products.

[0023] 2. To address the defect of inorganic zeolites readily agglomerating in oil-based formulations due to their polarity, this invention utilizes a long-chain silane coupling agent containing hexadecyl groups to deeply chemically modify the zeolite molecular sieve. The long carbon chains, like "tentacles," are densely distributed on the zeolite surface, not only significantly reducing the surface energy of the particles and making them highly oleophilic, but also constructing a strong steric hindrance layer between the particles. This long-chain repulsive force effectively counteracts the van der Waals forces between the particles, enabling them to remain stably suspended in the carrier oil for a long period, achieving excellent performance with zero oil separation after 30 days of standing and an extremely low centrifugal separation rate (≤0.8%).

[0024] 3. This invention introduces an ultrasonic cavitation in-situ dehydration process, achieving ultrafine dispersion of the additive system. In traditional vacuum dehydration processes, inorganic powders are prone to severe "secondary agglomeration" due to capillary contraction. This invention simultaneously introduces ultrasonic waves of specific frequency and power density during the dehydration stage. Utilizing the high-pressure microjets generated at the microscale by the ultrasonic cavitation effect, it can effectively and situ pulverize zeolite particles attempting to clump together. This process, without introducing additional mechanical grinding equipment, precisely and stably compresses the final system's particle size (D90) to an ultrafine level below 5μm, greatly improving the uniformity of additive dispersion in the PVC matrix.

[0025] 4. This invention overcomes the limitations of traditional compound additives that rely solely on temperature or time for production, instead using the thixotropic index (2.5-3.5) as a core process control indicator. By monitoring the fluid state online, it ensures that the system self-assembles into a stable three-dimensional network structure to prevent sedimentation during the cooling phase through intermolecular forces. This structure endows the product with excellent thixotropic properties: maintaining high viscosity during static storage to prevent particle sedimentation, while rapidly reducing viscosity and restoring fluidity during industrial pumping or high-shear processing, thus meeting the automated processing needs of downstream factories. Attached Figure Description

[0026] Figure 1 The D90 particle size distribution of the dispersed particles in the systems of Examples 1-3 and Comparative Examples 1-5 was determined using a laser particle size analyzer. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] The piperazine pyrophosphate introduced in this invention during zeolite modification acts as a grafting promoter. Its mechanism of action is twofold: firstly, the nitrogen atoms in the piperazine pyrophosphate molecule can form hydrogen bonds with the silanol groups on the zeolite surface, thereby activating the zeolite surface and making it easier for it to chemically bond with silane coupling agents; secondly, its piperazine ring may regulate the hydrolysis-condensation rate of the long-chain silane coupling agent (hexadecyltrimethoxysilane) on the zeolite surface through steric hindrance, guiding it to form a more ordered and dense grafted layer, rather than a disordered multilayer physical adsorption. Through this dual action of catalysis and regulation, modified zeolite with higher grafting rate and more stable oleophilicity is ultimately obtained.

[0029] Example 1: A method for producing an oil-based PVC compounding additive: Step (1): Mix 100 parts by weight of cashew phenol with 43 parts by weight of acetic anhydride, heat and reflux at 100°C for 3 hours, and distill under reduced pressure to obtain cashew phenol acetate intermediate; then cool to 60°C, add 20 parts by weight of glacial acetic acid and 8 parts by weight of strong acid cation exchange resin, and slowly add 70 parts by weight of 30% hydrogen peroxide under stirring. Heat to 70°C and stir for 4 hours. Filter while hot to remove and recover the solid strong acid cation exchange resin catalyst. Let the filtrate stand to separate into layers. Take the upper oil phase and wash it twice with 2% sodium carbonate aqueous solution, and then wash it with hot deionized water until neutral. Finally, dehydrate the neutral oil phase at 100°C and -0.09 MPa vacuum for 2 hours, filter, and obtain cashew phenol modified epoxy ester.

[0030] Step (2): Mix 100 parts by weight of choline chloride and 85 parts by weight of urea, dried to constant weight under vacuum at 70°C, and heat to 80°C to initially eutecticly form a translucent paste; then, under constant temperature stirring, slowly add 30 parts by weight of sodium perchlorate monohydrate, controlling the exothermic reaction system until the solid completely melts to form a homogeneous transparent liquid, and then cool to room temperature after degassing under vacuum at -0.1MPa to obtain a ternary deep eutectic solvent of sodium perchlorate-choline chloride-urea.

[0031] Step (3): Add 100 parts by weight of zeolite powder to 500 parts by weight of ethanol, and sonicate for 30 min to obtain a zeolite powder-ethanol suspension; add 10 parts by weight of hexadecyltrimethoxysilane to 40 parts by weight of acidic water-ethanol mixed solvent (the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:7, and the pH value is adjusted to 4.0 with glacial acetic acid), sonicate for 30 min, slowly add to the zeolite powder-ethanol suspension, add 18 parts by weight of piperazine pyrophosphate, reflux and stir at 70℃ for 3 h, wash, dry, and pulverize by airflow to a particle size D90≤5μm to obtain long-chain lipophilic grafted modified zeolite.

[0032] Step (4), pre-dispersion: 60 parts by weight of bio-based carrier oil are pumped into a reactor equipped with a high-shear dispersion device and a vacuum system. Stirring is started, and 24 parts by weight of long-chain lipophilic grafted modified zeolite are added at a uniform speed. High-shear dispersion is carried out at a speed of 2500 r / min for 15 min to obtain a primary suspension oil.

[0033] Step (5), in-situ ultrasonic cavitation dehydration: Raise the temperature of the primary suspended oil to 80°C, start the ultrasonic generator, and control the ultrasonic frequency of the ultrasonic generator to 20kHz and the power density to 0.3W / cm³. 3 At the same time, the vacuum pump is turned on to bring the vacuum level inside the vessel to -0.08MPa and maintain it for 40 minutes.

[0034] Step (6), Phase transfer complexation mixing: Remove the vacuum, and slowly add 16 parts by weight of sodium perchlorate-choline chloride-urea ternary eutectic solvent and 1.3 parts by weight of antioxidant 1010 to the reactor under stirring. Adjust the stirring speed to 600 r / min, and continue mixing at a constant temperature for 30 min to form a microemulsion liquid composite system.

[0035] Step (7), Rheological monitoring and packaging: Stop heating, introduce circulating water to cool the microemulsion liquid composite system to below 40°C, use an online rheometer to monitor the fluid state, when the system reaches the target thixotropic index of 3.0, it indicates that a stable spatial network anti-settling structure has been formed inside the system, at this time it is transferred to the finished product storage tank for metering and packaging to obtain oil-based PVC compound additive.

[0036] Example 2:

[0037] A method for producing an oil-based PVC compounding additive: Step (1): Mix 100 parts by weight of cashew phenol with 35 parts by weight of acetic anhydride, heat and reflux at 120°C for 3 hours, and distill under reduced pressure to obtain cashew phenol acetate intermediate; then cool to 50°C, add 15 parts by weight of glacial acetic acid and 5 parts by weight of strong acid cation exchange resin, and slowly add 60 parts by weight of 30% hydrogen peroxide under stirring. Heat to 65°C and stir for 5 hours. Filter while hot to remove and recover the solid strong acid cation exchange resin catalyst. Let the filtrate stand to separate into layers. Take the upper oil phase and wash it twice with 1% sodium carbonate aqueous solution, and then wash it with hot deionized water until neutral. Finally, dehydrate the neutral oil phase at 90°C and -0.09 MPa vacuum for 3 hours, filter, and obtain cashew phenol modified epoxy ester.

[0038] Step (2): Mix 100 parts by weight of choline chloride and 80 parts by weight of urea, dried to constant weight under vacuum at 60°C, and heat to 70°C to initially eutecticly form a translucent paste; then, under constant temperature stirring, slowly add 20 parts by weight of sodium perchlorate monohydrate, controlling the exothermic reaction system until the solid completely melts to form a homogeneous transparent liquid, and then cool to room temperature after degassing under vacuum at -0.08MPa to obtain a ternary deep eutectic solvent of sodium perchlorate-choline chloride-urea.

[0039] Step (3): Add 100 parts by weight of zeolite powder to 400 parts by weight of ethanol, and sonicate for 20 min to obtain a zeolite powder-ethanol suspension; add 5 parts by weight of hexadecyltrimethoxysilane to 30 parts by weight of acidic water-ethanol mixed solvent (the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:4, and the pH value is adjusted to 5.0 with glacial acetic acid), sonicate for 40 min, slowly add to the zeolite powder-ethanol suspension, add 10 parts by weight of piperazine pyrophosphate, reflux and stir at 80℃ for 2 h, wash, dry, and pulverize by airflow to a particle size D90≤5μm to obtain long-chain oleophilic grafted modified zeolite.

[0040] Step (4), pre-dispersion: 50 parts by weight of bio-based carrier oil are pumped into a reactor equipped with a high-shear dispersion device and a vacuum system. Stirring is started, and 15 parts by weight of long-chain lipophilic grafted modified zeolite are added at a uniform speed. High-shear dispersion is carried out at a speed of 2500 r / min for 15 min to obtain a primary suspension oil.

[0041] Step (5), in-situ ultrasonic cavitation dehydration: Raise the temperature of the primary suspended oil to 75°C, start the ultrasonic generator, and control the ultrasonic frequency of the ultrasonic generator to 25kHz and the power density to 0.5W / cm³. 3 At the same time, the vacuum pump is turned on to bring the vacuum level inside the vessel to -0.095MPa and maintain it for 30 minutes.

[0042] Step (6), Phase transfer complexation mixing: Remove the vacuum, and slowly add 10 parts by weight of sodium perchlorate-choline chloride-urea ternary eutectic solvent and 0.5 parts by weight of antioxidant 168 to the reactor under stirring. Adjust the stirring speed to 500 r / min, and continue mixing for 20 min at constant temperature to form a microemulsion liquid composite system.

[0043] Step (7), Rheological monitoring and packaging: Stop heating, introduce circulating water to cool the microemulsion liquid composite system to below 40°C, use an online rheometer to monitor the fluid state, when the system reaches the target thixotropic index of 3.5, it indicates that a stable spatial network anti-settling structure has been formed inside the system, at this time it is transferred to the finished product storage tank for metering and packaging to obtain the oil-based PVC compound additive.

[0044] Example 3:

[0045] A method for producing an oil-based PVC compounding additive: Step (1): Mix 100 parts by weight of cashew phenol with 50 parts by weight of acetic anhydride, heat and reflux at 80°C for 4 hours, and distill under reduced pressure to obtain cashew phenol acetate intermediate; then cool to 50°C, add 25 parts by weight of glacial acetic acid and 10 parts by weight of strong acid cation exchange resin, and slowly add 80 parts by weight of 27% hydrogen peroxide under stirring, heat to 70°C and stir for 4 hours, filter while hot to remove and recover the solid strong acid cation exchange resin catalyst, let the filtrate stand to separate into layers, take the upper oil phase and wash it once with 3% sodium carbonate aqueous solution, and then wash it with hot deionized water until neutral; finally, dehydrate the neutral oil phase at 100°C and -0.09MPa vacuum for 3 hours, filter, and obtain cashew phenol modified epoxy ester.

[0046] Step (2): Mix 100 parts by weight of choline chloride and 90 parts by weight of urea, dried to constant weight under vacuum at 80°C, and heat to 80°C to initially eutecticly form a translucent paste; then, under constant temperature stirring, slowly add 40 parts by weight of sodium perchlorate monohydrate, controlling the exothermic reaction system until the solid completely melts to form a homogeneous transparent liquid, and then cool to room temperature after degassing under vacuum at -0.1MPa to obtain a ternary deep eutectic solvent of sodium perchlorate-choline chloride-urea.

[0047] Step (3): Add 100 parts by weight of zeolite powder to 600 parts by weight of ethanol, and sonicate for 40 min to obtain a zeolite powder-ethanol suspension; add 15 parts by weight of hexadecyltrimethoxysilane to 50 parts by weight of acidic water-ethanol mixed solvent (the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:9, and the pH value is adjusted to 5.5 with glacial acetic acid), sonicate for 60 min, slowly add to the zeolite powder-ethanol suspension, add 25 parts by weight of piperazine pyrophosphate, reflux and stir at 80℃ for 4 h, wash, dry, and pulverize by airflow to a particle size D90≤5μm to obtain long-chain oleophilic grafted modified zeolite.

[0048] Step (4), Pre-dispersion: Pump 70 parts by weight of bio-based carrier oil into a reactor equipped with a high-shear dispersion device and a vacuum system, turn on the stirring, add 30 parts by weight of long-chain lipophilic grafted modified zeolite at a uniform speed, and perform high-shear dispersion for 20 minutes at a speed of 3000 r / min to obtain a primary suspension oil.

[0049] Step (5), in-situ ultrasonic cavitation dehydration: Raise the temperature of the primary suspended oil to 85°C, start the ultrasonic generator, and control the ultrasonic frequency of the ultrasonic generator to 25kHz and the power density to 0.5W / cm³. 3 At the same time, the vacuum pump is turned on to bring the vacuum level inside the vessel to -0.08MPa and maintain it for 45 minutes.

[0050] Step (6), Phase transfer complexation mixing: Remove the vacuum, and slowly add 25 parts by weight of sodium perchlorate-choline chloride-urea ternary eutectic solvent and 2 parts by weight of antioxidant 1076 to the reactor under stirring. Adjust the stirring speed to 800 r / min, and continue mixing for 20 min at constant temperature to form a microemulsion liquid composite system.

[0051] Step (7), Rheological monitoring and packaging: Stop heating, introduce circulating water to cool the microemulsion liquid composite system to below 40°C, use an online rheometer to monitor the fluid state, when the system reaches the target thixotropic index of 2.5, it indicates that a stable spatial network anti-settling structure has been formed inside the system, at this time it is transferred to the finished product storage tank for metering and packaging to obtain oil-based PVC compound additive.

[0052] Comparative Example 1: The difference from Example 1 is that epoxidized soybean oil replaces cashew phenol modified epoxy ester.

[0053] Comparative Example 2: The difference from Example 1 is that sodium perchlorate monohydrate solid powder is used instead of sodium perchlorate-choline chloride-urea ternary eutectic solvent.

[0054] Comparative Example 3: The difference from Example 1 is that ordinary zeolite powder is used instead of long-chain lipophilic grafted zeolite.

[0055] Comparative Example 4: The difference from Example 1 is that aminopropyltriethoxysilane is used instead of hexadecyltrimethoxysilane. The specific differences are as follows: Step (3): Add 100 parts by weight of zeolite powder to 500 parts by weight of ethanol, and sonicate for 30 min to obtain a zeolite powder-ethanol suspension; add 10 parts by weight of aminopropyltriethoxysilane to 40 parts by weight of acidic water-ethanol mixed solvent (the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:7, and the pH value is adjusted to 4.0 with glacial acetic acid), sonicate for 30 min, slowly add to the zeolite powder-ethanol suspension, add 18 parts by weight of piperazine pyrophosphate, reflux and stir at 70℃ for 3 h, wash, dry, and pulverize by airflow to a particle size D90≤5μm to obtain long-chain lipophilic grafted modified zeolite.

[0056] The other methods and steps are the same as in Example 1.

[0057] Comparative Example 5: The difference from Example 1 is that piperazine pyrophosphate was not added. The specific differences are as follows: Step (3): Add 100 parts by weight of zeolite powder to 500 parts by weight of ethanol, and sonicate for 30 min to obtain a zeolite powder-ethanol suspension; add 10 parts by weight of hexadecyltrimethoxysilane to 40 parts by weight of acidic water-ethanol mixed solvent (the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:7, and the pH value is adjusted to 4.0 with glacial acetic acid), sonicate for 30 min, and slowly add it dropwise to the zeolite powder-ethanol suspension, reflux and stir at 70℃ for 3 h, wash, dry, and pulverize by airflow to a particle size D90≤5μm to obtain long-chain oleophilic grafted modified zeolite.

[0058] The other methods and steps are the same as in Example 1.

[0059] Thermal stability test: The additives of Examples 1-3 and Comparative Examples 1-5 were mixed evenly with 100 parts of PVC resin (polyvinyl chloride resin), and Congo red test was performed at 180°C. The time (min) for the test paper to turn blue was recorded.

[0060] Test the centrifugation stratification rate: Take 10g of compound auxiliary agent sample and place it in a centrifuge tube. Centrifuge at 3000r / min for 15min and calculate the percentage of the bottom precipitate in the total volume.

[0061] Test the oil separation rate at room temperature: Place the compound additive sample in a transparent graduated tube and let it stand at 25℃ for 30 days. Record the percentage of the supernatant (oil separation) in the total volume.

[0062] Particle dispersion was tested: The D90 particle size (μm) of the dispersed particles in the system was determined using a laser particle size analyzer.

[0063] Table 1 Performance Tests of Oil-Based PVC Compound Additives

[0064] As can be seen from the data in Table 1, the oil-based PVC compound additives in Examples 1-3 exhibit excellent comprehensive performance. The fundamental reason lies in their perfect synergy between a chemical multi-target thermal stabilization mechanism and a physical full-space anti-settling process. Chemically, the self-synthesized cashew phenol-modified epoxy ester not only possesses excellent resin compatibility but also actively opens the ring to efficiently capture HCl. Simultaneously, the deep eutectic solvation technology transforms traditional solid sodium perchlorate into a room-temperature liquid complex, achieving uniform dispersion at the molecular level and blocking dechlorination. The synergistic effect of the multi-component combination with the grafting accelerator successfully constructs a robust anti-degradation barrier, significantly extending the thermal stability time of PVC. Physically and technologically, the deep chemical bonding of hexadecyl long carbon chains to zeolite constructs a strong steric hindrance layer, greatly reducing particle surface energy. Combined with innovative ultrasonic cavitation in-situ dehydration technology, high-pressure micro-jet effectively pulverizes secondary agglomerates, resulting in a system particle size (D90) of less than 5 μm (e.g., ...). Figure 1 (As shown). Ultimately, by strictly monitoring online rheology to lock in a specific thixotropic index, the system self-assembles into a stable three-dimensional spatial network structure, solving the industry problems of easy stratification and oil separation in traditional solid-liquid suspension systems.

[0065] Comparative Example 1: The difference from Example 1 is that epoxidized soybean oil replaced cashew phenol modified epoxy ester, which weakened the system's ability to actively capture HCl, resulting in a significant decrease in thermal stability time.

[0066] Comparative Example 2: The difference from Example 1 is that sodium perchlorate monohydrate solid powder replaced the sodium perchlorate-choline chloride-urea ternary eutectic solvent, resulting in sodium perchlorate failing to convert into a room-temperature liquid complex and thus failing to disperse uniformly in the oil phase matrix. The solid powder not only has a small contact area and cannot effectively block the dehydrochlorination reaction, leading to a shortened thermal stability time, but also easily forms hard agglomerates in the system, destroying the overall physical suspension stability. The system particle size (D90) reached 15.8 μm (e.g., ...). Figure 1 (As shown).

[0067] Comparative Example 3: The difference from Example 1 is that ordinary zeolite powder replaced the long-chain oleophilic graft modified zeolite, which could not effectively reduce the high surface energy of the particles, resulting in severe polar agglomeration of zeolite particles in the oil phase, leading to extremely high centrifugal stratification rate and severe oil separation upon standing.

[0068] Comparative Example 4: The difference from Example 1 is that aminopropyltriethoxysilane was used instead of hexadecyltrimethoxysilane. Although the zeolite underwent surface treatment, the steric hindrance layer thickness and repulsive force were insufficient due to the short carbon chains. During long-term physical full-space anti-settling processes, the short chains could not provide sufficient steric hindrance to completely block the van der Waals forces between particles, resulting in the system's long-term anti-oil separation and anti-settling performance being inferior to that of the Example. Trace amounts of sediment still appeared at the bottom after standing.

[0069] Comparative Example 5: The difference from Example 1 is that piperazine pyrophosphate was not added, and the synergistic effect of the grafting promoter was missing from the system, resulting in an imperfect anti-degradation barrier and a break in the synergistic chain of the multi-target thermal stability mechanism, which led to a reduction in the thermal stability time of PVC. On the other hand, the lack of promoter may also lead to a decrease in the silane bonding rate on the zeolite surface, which indirectly affects the compactness of the steric hindrance layer, and thus has a slight negative impact on the dispersion and anti-settling properties of the system.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An oil-based PVC compounding additive, characterized in that, The oil-based PVC compound additives include 50-70 parts by weight of bio-based carrier oil, 10-25 parts by weight of sodium perchlorate-choline chloride-urea ternary eutectic solvent, 15-30 parts by weight of long-chain lipophilic grafted modified zeolite, and 0.5-2 parts by weight of antioxidant. The sodium perchlorate-choline chloride-urea ternary eutectic solvent is a room-temperature liquid complex formed by sodium perchlorate monohydrate and a hydrogen bond donor under heating conditions by breaking the lattice energy and reconstructing the three-dimensional hydrogen bond network between molecules. The long-chain oleophilic graft-modified zeolite is a hydrophobic and oleophilic zeolite obtained by chemically bonding the surface of a zeolite molecular sieve with a long-chain silane coupling agent containing hexadecyl in the presence of a grafting promoter, so that the surface is coated with long carbon chains.

2. The oil-based PVC compounding additive according to claim 1, characterized in that, The antioxidant is one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

3. The oil-based PVC compounding additive according to claim 1, characterized in that, The bio-based carrier oil is a cashew phenol-modified epoxy ester, and its preparation method includes the following steps: Cashew phenol was mixed with acetic anhydride and refluxed at 80-120℃ for 3-4 hours. The mixture was then distilled under reduced pressure to obtain a cashew phenol acetate intermediate. The temperature was then lowered to 50-60℃, and glacial acetic acid and a strong acid cation exchange resin were added. Under stirring, 27-30% hydrogen peroxide was slowly added dropwise. The mixture was heated to 65-70℃ and stirred for 4-5 hours. The mixture was filtered while hot to remove and recover the solid strong acid cation exchange resin catalyst. The filtrate was allowed to stand and separate into layers. The upper oil phase was washed 1-2 times with a 1-3% sodium carbonate aqueous solution, and then washed with hot deionized water until neutral. Finally, the neutral oil phase was dehydrated at 90-100℃ and a vacuum of -0.09 MPa for 2-3 hours, and then filtered to obtain a cashew phenol-modified epoxy ester.

4. The oil-based PVC compounding additive according to claim 3, characterized in that, The mass ratio of cashew phenol, acetic anhydride, glacial acetic acid, strong acid cation exchange resin, and hydrogen peroxide with a mass fraction of 27-30% is 100:(35-50):(15-25):(5-10):(60-80).

5. The oil-based PVC compounding additive according to claim 1, characterized in that, The preparation method of the sodium perchlorate-choline chloride-urea ternary deep eutectic solvent includes the following steps: choline chloride and urea, dried to constant weight under vacuum at 60-80℃, are mixed and heated to 70-80℃ to initially eutecticly form a translucent paste; then, under constant temperature stirring, sodium perchlorate monohydrate is slowly added, controlling the reaction system to be exothermic, until the solid completely dissolves to form a homogeneous transparent liquid; after degassing under vacuum at -0.08MPa to -0.1MPa, the mixture is cooled to room temperature to obtain the sodium perchlorate-choline chloride-urea ternary deep eutectic solvent.

6. The oil-based PVC compounding additive according to claim 5, characterized in that, The mass ratio of choline chloride, urea, and sodium perchlorate monohydrate is 100:(80-90):(20-40).

7. The oil-based PVC compounding additive according to claim 1, characterized in that, The preparation process of the long-chain lipophilic grafted modified zeolite is as follows: Zeolite powder was added to ethanol and ultrasonically treated for 20-40 min to obtain a zeolite powder-ethanol suspension. Hexadecyltrimethoxysilane was added to an acidic water-ethanol mixed solvent and ultrasonically treated for 30-60 min. It was then slowly added dropwise to the zeolite powder-ethanol suspension. Piperazine pyrophosphate was added, and the mixture was refluxed and stirred at 70-80℃ for 2-4 h. The mixture was washed, dried, and pulverized by airflow to a particle size D90≤5μm to obtain long-chain oleophilic grafted modified zeolite.

8. The oil-based PVC compounding additive according to claim 7, characterized in that, The mass ratio of the zeolite powder, ethanol, hexadecyltrimethoxysilane, acidic water-ethanol mixed solvent, and piperazine pyrophosphate is 100:(400-600):(5-15):(30-50):(10-25); wherein the acidic water-ethanol mixed solvent is a mixture of deionized water and ethanol with a mass ratio of 1:(4-9), and the pH value is adjusted to 4.0-5.5 with glacial acetic acid.

9. A method for producing an oil-based PVC compounding additive as described in any one of claims 1-8, characterized in that, The production method of the oil-based PVC compound additive includes the following steps: S1. Pre-dispersion: The bio-based carrier oil is pumped into a reactor equipped with a high-shear dispersion device and a vacuum system. Stirring is started, and long-chain lipophilic grafted modified zeolite is added at a uniform speed. High-shear dispersion is carried out at a speed of 2500-3000 r / min for 15-20 min to obtain a primary suspension oil. S2. In-situ dehydration via ultrasonic cavitation: Raise the temperature of the primary suspended oil to 75-85℃, start the ultrasonic generator, and control the ultrasonic frequency of the ultrasonic generator to 20-25kHz and the power density to 0.3-0.5W / cm³. 3 At the same time, turn on the vacuum pump to make the vacuum degree inside the vessel reach -0.08MPa to -0.095MPa, and maintain it for 30-45 minutes; S3. Phase transfer complexation mixing: Remove the vacuum and slowly add sodium perchlorate-choline chloride-urea ternary eutectic solvent and antioxidant to the reactor under stirring. Adjust the stirring speed to 500-800 r / min and continue mixing at constant temperature for 20-30 min to form a microemulsion liquid composite system. S4. Rheological monitoring and packaging: Stop heating and introduce circulating water to cool the microemulsion liquid composite system to below 40°C. Use an online rheometer to monitor the fluid state. When the system reaches the target thixotropic index of 2.5-3.5, it indicates that a stable spatial network anti-settling structure has been formed inside the system. At this time, transfer it to the finished product storage tank for metering and packaging to obtain the oil-based PVC compound additive.

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