Diisononyl sebacate as well as preparation method and application thereof
By optimizing the preparation method of diisononyl sebacate, using concentrated sulfuric acid catalyst and precisely controlling process parameters, the environmental performance and plasticizing efficiency issues of environmentally friendly plasticizers in medical materials were solved, achieving the preparation of low-cost, high-purity diisononyl sebacate, suitable for medical PVC products.
Patent Information
- Application Number
- CN202511263811.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-05
- Publication Date
- 2025-12-16
AI Technical Summary
Existing environmentally friendly plasticizers have problems such as poor environmental performance, low plasticizing efficiency, low purity and high production cost in the field of medical materials. In particular, traditional sebacic acid ester preparation methods have defects such as low reaction efficiency and high alcohol residue, and the investment cost of high-end equipment is high.
A method for preparing diisononyl sebacate was adopted, using concentrated sulfuric acid as a catalyst. By precisely controlling the esterification, neutralization, dehydration, and decolorization processes, combined with nitrogen protection, precise catalyst dosage, and suitable temperature, the process parameters were optimized to obtain high-purity, low-VOC diisononyl sebacate.
It enables the efficient and low-cost production of high-purity diisononyl sebacate, meeting the safety and environmental protection requirements of medical materials. It has excellent plasticizing efficiency and material compatibility, and is suitable for medical PVC products such as infusion tubes, blood bags and artificial catheters.
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Abstract
Description
Technical Field
[0001] This application relates to the field of environmentally friendly materials technology, specifically to diisononyl sebacate, its preparation method, and its application. Background Technology
[0002] With increasingly stringent environmental regulations and ever-improving medical and health standards, the application of traditional plasticizers in the field of medical materials faces significant challenges. Currently widely used phthalate plasticizers, due to their potential reproductive toxicity and endocrine disruption effects, have been explicitly restricted from use in medical devices by regulations such as the EU REACH. Although various environmentally friendly alternatives have emerged on the market, these products still face significant technical bottlenecks in practical applications.
[0003] Existing environmentally friendly plasticizers face three major technical challenges: First, in terms of performance, citrate esters exhibit high volatility at high temperatures, resulting in a 15-20% quality loss during processing; epoxy vegetable oil plasticizers have poor compatibility with PVC substrates and are prone to "sweating"; while traditional sebacic acid esters, although exhibiting excellent low-temperature performance, have low plasticizing efficiency, often requiring an addition of 40-60 phr to achieve the desired effect. Second, in terms of preparation processes, the currently widely used concentrated sulfuric acid catalytic method not only produces more than 3% sulfonation byproducts but also leads to a darker product color; simultaneously, due to insufficient precision in the neutralization process, the product's acid value fluctuates significantly; and imperfect dehydration processes result in a high moisture content in the final product, severely affecting the processing stability of PVC materials.
[0004] It is particularly noteworthy that the existing methods for preparing dioctyl sebacate have drawbacks such as low reaction efficiency and high alcohol residue. Although the supercritical esterification method used in some technologies has improved product performance, the equipment investment cost is high and the molecular weight distribution of the product is wide.
[0005] In summary, the current field of environmentally friendly plasticizers urgently needs to address three core issues: how to balance the contradiction between environmental performance and plasticizing efficiency; how to achieve the purity requirements of medical-grade products; and how to control production costs within an industrially feasible range through process innovation. Breakthroughs in these key issues are of great significance for promoting the application of environmentally friendly plasticizers in high-end medical fields. Based on the above statements, this application provides diisononyl sebacate, its preparation method, and its applications. Summary of the Invention
[0006] To address the shortcomings of existing environmentally friendly plasticizers, such as poor environmental performance, low plasticizing efficiency, low purity, and high production costs, this application provides diisononyl sebacate, its preparation method, and its applications.
[0007] In the first aspect, this application provides diisononyl sebacate, using the following technical solution: Diisononyl sebacate, characterized in that it is made from the following raw materials in the following weight ratio: 12-14 kg sebacate, 20-30 kg isononyl alcohol, 0.104-0.156 kg catalyst, 4-6 kg neutralizing agent, 3.0-3.3 kg distilled water, and 0.5-1.5 kg decolorizing agent.
[0008] Preferably, the diisononyl sebacate is made from the following raw materials in the following weight ratio: 13 kg sebacate, 25 kg isononyl alcohol, 0.15 kg catalyst, 5 kg neutralizer, 3.15 kg distilled water, and 1 kg decolorizing agent.
[0009] Preferably, the catalyst is concentrated sulfuric acid; the neutralizing agent is a liquid alkali with a mass fraction of 30-34%; and the decolorizing agent is activated carbon.
[0010] Secondly, this application provides a method for preparing diisononyl sebacate, using the following technical solution: The preparation method of diisononyl sebacate includes the following steps: S1. Weigh sebacic acid, isononol and concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.095--0.1 MPa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat up and stir the reaction. When the reaction temperature is reached, evacuate to a vacuum degree of -0.095--0.1Mpa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is less than 0.1 mg KOH / g, cool down, add 30-34% liquid alkali and distilled water, stir, and neutralize until the acid value is ≤0.04 mg KOH / g. S4. Heat up and steam the alcohol until the isononol residue is <500ppm, then turn on the vacuum system to dehydrate until the moisture content is <300ppm to obtain crude ester. S5. Cool the crude ester, add activated carbon, stir, and filter through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0011] Preferably, in step S2, the heating rate is 8-12℃ / min, the temperature is raised to 135-145℃, the stirring speed is 250-350rpm, and the reaction is carried out at atmospheric pressure for 4-5 hours.
[0012] Preferably, in step S3, the cooling rate is 8-12℃ / min, the temperature is reduced to 75-85℃, and the stirring parameters are: speed 250-350rpm, time 25-35min.
[0013] Preferably, in step S4, the heating rate is 8-12℃ / min, and the temperature is raised to 170-190℃.
[0014] Preferably, in step S5, the cooling rate is 8-12℃ / min, the temperature is reduced to 60-80℃, the stirring speed is 250-350rpm, and the stirring time is 30-40min.
[0015] Thirdly, this application provides the application of diisononyl sebacate as a primary plasticizer in medical PVC products.
[0016] Preferably, the PVC products include infusion tubes, blood bags, artificial catheters, or medical films.
[0017] In summary, this application has the following beneficial effects: (1) In terms of environmental protection and safety, this product uses concentrated sulfuric acid as a catalyst, replacing the toxic or high-cost composite catalyst system in the traditional process. Not only are the raw materials readily available and the cost significantly reduced, but also by-products and residual impurities are effectively removed through optimized neutralization, dehydration and decolorization processes. The final product has extremely high purity and low VOC content, fully meeting the strict requirements of medical materials for safety and environmental protection, and avoiding the toxicity risks of phthalic plasticizers.
[0018] (2) In terms of process efficiency and product quality, this method achieves high efficiency and stability in the reaction process by precisely controlling the temperature, pressure and time parameters of key stages such as esterification, neutralization, de-alcoholization, dehydration and decolorization. The concentrated sulfuric acid catalyst has high activity, which greatly shortens the esterification time and improves production efficiency; in the neutralization stage, the amount of liquid alkali added is precisely controlled by real-time monitoring of acid value, ensuring that the acid value is stable at ≤0.04 mgKOH / g; the subsequent steam de-alcoholization and vacuum dehydration operations effectively reduce the residue of isononanol and moisture. Finally, after activated carbon decolorization and filtration, the product obtained is transparent, stable in performance, and has a low hydroxyl value, showing excellent plasticizing efficiency and material compatibility.
[0019] (3) In terms of economic efficiency and industrial feasibility, the raw materials used in this invention are inexpensive and widely available. The overall process is simple, the operating conditions are mild, and the equipment requirements are low, making it easy to scale up production. It has good economic efficiency and industrialization prospects. When the product is used as the main plasticizer in medical PVC products (such as infusion tubes, blood bags, artificial catheters, and medical films), the addition amount is low, the compatibility is good, and it has the characteristics of low migration and low hemolysis rate. Its comprehensive performance reaches or even exceeds that of traditional plasticizers and high-end environmentally friendly plasticizers, achieving an effective balance between product performance, safety, and production cost. Detailed Implementation
[0020] The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0021] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.
[0022] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available products.
[0023] Examples 1-3 provide a method for preparing diisononyl sebacate.
[0024] Example 1 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 12kg sebacic acid, 20kg isononol and 0.104kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.095Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 135°C at a rate of 8°C / min, stir at 250 rpm for 4 hours, and simultaneously evacuate to a vacuum of -0.095 MPa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 75°C at a cooling rate of 8°C / min, add 4 kg of 30% liquid alkali and 3 kg of distilled water, stir at 250 rpm for 25 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 170°C at a heating rate of 8°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 60°C at a cooling rate of 8°C / min, 0.5 kg of activated carbon was added, and the mixture was stirred at 250 rpm for 30 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0025] Example 2 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0026] Example 3 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 14kg sebacic acid, 30kg isononol and 0.156kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.1Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 145°C at a rate of 12°C / min, stir at 350 rpm for 5 hours, and simultaneously evacuate to a vacuum of -0.1 MPa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 85°C at a cooling rate of 12°C / min, add 6 kg of 34% liquid alkali and 3.3 kg of distilled water, stir at 350 rpm for 35 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 190℃ at a heating rate of 12℃ / min, steam-purge the alcohol until the isononol residue is 500ppm, then turn on the vacuum system to dehydrate until the water content is 300ppm to obtain crude ester. S5. The crude ester was cooled to 80°C at a cooling rate of 12°C / min, 1.5 kg of activated carbon was added, and the mixture was stirred at 350 rpm for 40 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0027] Comparative Example 1 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0028] Comparative Example 2 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.3kg concentrated sulfuric acid according to the weight ratio, and add them into the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0029] Comparative Example 3 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 120°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0030] Comparative Example 4 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 180°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum degree of -0.098 MPa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0031] Comparative Example 5 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 10 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0032] Comparative Example 6 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 1500ppm, then turn on the vacuum system to dehydrate until the water content is 300ppm to obtain crude ester. S5. The crude ester was cooled to 70°C at a cooling rate of 10°C / min, 1 kg of activated carbon was added, and the mixture was stirred at 300 rpm for 35 min. After stirring, the mixture was filtered through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
[0033] Comparative Example 7 The preparation method of the diisononyl sebacate includes the following steps: S1. Weigh 13kg sebacic acid, 25kg isononol and 0.15kg concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.098Mpa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat to 140°C at a rate of 10°C / min, stir at 300 rpm for 4.5 hours, and simultaneously evacuate to a vacuum of -0.098 MPa to promote the discharge of generated water, and take samples regularly to test the acid value. S3. When the acid value is 0.1 mg KOH / g, cool down to 80°C at a cooling rate of 10°C / min, add 5 kg of 32% liquid alkali and 3.15 kg of distilled water, stir at 300 rpm for 30 min, and neutralize to an acid value of 0.04 mg KOH / g. S4. Heat to 180°C at a heating rate of 10°C / min, steam-purge the alcohol until the isononol residue is 500 ppm, then turn on the vacuum system to dehydrate until the water content is 300 ppm to obtain crude ester. S5. The crude ester is cooled to 70°C at a cooling rate of 10°C / min and filtered through a polypropylene filter cloth plate and frame filter to obtain diisononyl sebacate.
[0034] Performance index testing and yield calculation The acid values of diisononyl sebacate described in Examples 1-3 and Comparative Examples 1-7 were determined using the method specified in HG / T2708, and the results are shown in Table 1. The hydroxyl values of diisononyl sebacate described in Examples 1-3 and Comparative Examples 1-7 were determined using the method specified in GB / T 12008.6-2010, and the results are shown in Table 1. The VOC values of diisononyl sebacate described in Examples 1-3 and Comparative Examples 1-7 were determined using the method specified in ISO 16000-6, and the results are shown in Table 1. The yields of diisononyl sebacate described in Examples 1-3 and Comparative Examples 1-7 were calculated, and the results are shown in Table 1. The calculation method was as follows: theoretical product mass = (mass of sebacate / molecular weight of sebacate) × molecular weight of diisononyl sebacate; yield (%) = actual product mass / theoretical product mass; the results are shown in Table 1.
[0035] Table 1. Performance indicators and yield of diisononyl sebacate Based on the results in the table above, it can be seen that the preparation process of diisononyl sebacate provided in this application exhibits excellent comprehensive performance and significant technical advantages. Through systematic comparative analysis of the examples and comparative examples, it is evident that the optimal process parameter system (nitrogen protection, precise catalyst dosage, suitable esterification temperature, accurate neutralization, and thorough de-alcoholization, dehydration, and decolorization) is key to obtaining high-performance products. The products in Examples 1-3 demonstrate excellent performance in core indicators: the acid value is stable at 0.02-0.04 mg KOH / g, indicating complete reaction and precise post-processing; the hydroxyl value is as low as 5.1-5.3 mg KOH / g, reflecting minimal alcohol residue; the VOCs values are all below 0.09%, proving high product purity and low volatile impurities; simultaneously, the yield remains above 85%, demonstrating the economic efficiency of the process.
[0036] The comparative results, on the contrary, demonstrate the necessity of process rigor: omitting nitrogen protection leads to oxidation side reactions, increasing acid value and VOCs; deviations in catalyst dosage or improper reaction temperature can cause an increase in side reactions or incomplete reactions, resulting in decreased yield and increased impurity content; excessive neutralizer can trigger saponification, severely damaging yield and increasing hydroxyl value; incomplete de-alcoholization will directly lead to excessive VOCs; and omitting decolorization will cause the produced diisononyl sebacate to be yellow, which, although not affecting chemical indicators, cannot meet the stringent appearance requirements of high-end applications.
[0037] In summary, through precise control of each step, this process successfully achieves a high degree of unity between product environmental friendliness, safety, and production efficiency. The resulting diisononyl sebacate fully meets the requirements of medical PVC products for low migration and low hemolysis rate of the main plasticizer. Its comprehensive performance far exceeds that of products from non-optimized processes, demonstrating outstanding industrialization value and application prospects.
[0038] The above specific embodiments are merely explanations of this application and are not intended to limit this application. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. Diisononyl sebacate, characterized in that, It is made from the following raw materials in the following weight ratio: 12-14 kg sebacic acid, 20-30 kg isononanol, 0.104-0.156 kg catalyst, 4-6 kg neutralizer, 3.0-3.3 kg distilled water, and 0.5-1.5 kg decolorizing agent.
2. The diisononyl sebacate according to claim 1, characterized in that, It is made from the following raw materials in the following weight ratio: 13kg sebacic acid, 25kg isononol, 0.15kg catalyst, 5kg neutralizer, 3.15kg distilled water, and 1kg decolorizing agent.
3. The diisononyl sebacate according to claim 1, characterized in that, The catalyst is concentrated sulfuric acid; the neutralizing agent is liquid alkali with a mass fraction of 30-34%; and the decolorizing agent is activated carbon.
4. A method for preparing diisononyl sebacate according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Weigh sebacic acid, isononol and concentrated sulfuric acid according to the weight ratio, and add them to the reaction vessel in sequence. Evacuate the vessel to a vacuum degree of -0.095--0.1 MPa, and then introduce nitrogen gas to normal pressure. S2. Turn on the heating and condensation system to circulate water, heat up and stir the reaction. When the reaction temperature is reached, evacuate to a vacuum degree of -0.095--0.1Mpa to promote the discharge of generated water, and take samples at regular intervals to test the acid value. S3. When the acid value is less than 0.1 mg KOH / g, cool down, add 30-34% liquid alkali and distilled water, stir, and neutralize until the acid value is ≤0.04 mg KOH / g. S4. Heat up and steam the alcohol until the isononol residue is <500ppm, then turn on the vacuum system to dehydrate until the moisture content is <300ppm to obtain crude ester. S5. Cool the crude ester, add activated carbon, stir, and filter through a polypropylene filter cloth plate and frame filter to obtain colorless and transparent diisononyl sebacate.
5. The method for preparing diisononyl sebacate according to claim 4, characterized in that, In step S2, the heating rate is 8-12℃ / min, the temperature is raised to 135-145℃, the stirring speed is 250-350rpm, and the reaction is carried out at atmospheric pressure for 4-5 hours.
6. The method for preparing diisononyl sebacate according to claim 4, characterized in that, In step S3, the cooling rate is 8-12℃ / min, and the temperature is reduced to 75-85℃. The stirring parameters are: speed 250-350rpm, time 25-35min.
7. The method for preparing diisononyl sebacate according to claim 4, characterized in that, In step S4, the heating rate is 8-12℃ / min, and the temperature is raised to 170-190℃.
8. The method for preparing diisononyl sebacate according to claim 4, characterized in that, In step S5, the cooling rate is 8-12℃ / min, the temperature is reduced to 60-80℃, the stirring speed is 250-350rpm, and the stirring time is 30-40min.
9. The use of diisononyl sebacate as a primary plasticizer in medical PVC products according to any one of claims 1-3.
10. The application of diisononyl sebacate as a main plasticizer in medical PVC products according to claim 9, characterized in that, The PVC products include infusion tubes, blood bags, artificial catheters, or medical films.