Skid-mounted diisononyl phthalate synthesis device and synthesis method

Abstract

The invention relates to a skid-mounted diisononyl phthalate synthesis device and a synthesis method, and belongs to the technical field of organic chemical synthesis. According to the method, the mixture of the catalyst and the isononyl alcohol and the mixture of the phthalic anhydride and the isononyl alcohol are directly mixed for the esterification reaction, the esterification reaction efficiency is high, the technological operation is simpler, and diisononyl phthalate in the prepared finished product is high in purity, low in acid value and low in viscosity and can be used as a plasticizer to be applied to PVC products; the molar ratio of isononyl alcohol and phthalic anhydride adopted in the esterification reaction is small, the amount of isononyl alcohol which is not completely reacted is relatively reduced while the conversion rate of diisononyl phthalate is ensured, and the difficulty of isononyl alcohol separation and recovery in the subsequent process steps is reduced; the skid-mounted synthesis device is formed by integrally mounting all the equipment on the same base, and is convenient to mount, small in occupied area and convenient to move.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical synthesis, and in particular to a skid-mounted diisononyl phthalate synthesis device and a synthesis method. Background Art

[0002] Plastic products are widely used in building materials, electronic devices, medical devices and other fields. Polyvinyl chloride (PVC) is one of the most widely circulated plastic products on the market. However, PVC has disadvantages such as poor light and heat stability. Under high temperature and long-term light exposure, it will decompose, change color, and reduce physical and chemical properties. It is often necessary to introduce plasticizers into PVC plastic products to greatly improve the performance of plastic products. Ortho-phenyl ester plasticizers are one of the most popular types of plasticizers on the market. They have a wide variety of products and high production of various varieties. At the same time, most products also have the characteristics of light color, low toxicity, good electrical properties, small volatile parts, less odor, and general low temperature resistance.

[0003] Among many ortho-phenyl ester plasticizers, diisononyl phthalate has good compatibility with PVC and will not have problems such as low solubility and product precipitation. At the same time, diisononyl phthalate is superior to other ortho-phenyl ester plasticizers in volatility, migration and non-toxicity, and can give the products good light resistance, heat resistance, aging resistance and electrical insulation properties.

[0004] At present, the production equipment of diisononyl phthalate has the defects of large floor space, many pipeline connections, and complex installation. Most of the existing preparation processes of diisononyl phthalate first mix isononyl alcohol and phthalic anhydride for monoesterification reaction, and then add a catalyst for double esterification reaction. The temperature rise procedure during the reaction is complicated, and the molar ratio of isononyl alcohol to phthalic anhydride is large, which increases the difficulty of removing isononyl alcohol from the esterification product in the subsequent process steps. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and to provide a skid-mounted diisononyl phthalate synthesis device and a synthesis method.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a method for synthesizing diisononyl phthalate, comprising the following steps:

[0008] S1, mixing a mixture of a catalyst and isononanol and a mixture of phthalic anhydride and isononanol for esterification reaction to obtain a crude esterification product;

[0009] S2, dealcoholizing the crude product of the esterification reaction obtained in step S1 to obtain a crude product of diisononyl phthalate;

[0010] S3, alkali-washing the crude diisononyl phthalate product obtained in step S2 in sequence to obtain an alkali-washed product;

[0011] S4, washing the alkali washed product obtained in step S3 with water to obtain a washed product;

[0012] S5, separating and purifying the washed product obtained in step S4;

[0013] S6, drying the product purified in step S5, and cooling it to obtain a finished product.

[0014] The invention directly mixes a mixture of a catalyst and isononyl alcohol and a mixture of phthalic anhydride and isononyl alcohol for esterification reaction. The esterification reaction efficiency is high and the process operation is simpler. The diisononyl phthalate in the prepared finished product has high purity, low acid value and low viscosity, and can be used as a plasticizer in PVC products.

[0015] As a preferred embodiment of the present invention, in step S1, the mass ratio of the catalyst to phthalic anhydride is (0.0003-0.0005):1; the molar ratio of the isononanol to phthalic anhydride is (1-4):1, and more preferably (1.5-2):1.

[0016] Compared with the prior art, the molar ratio of isononyl alcohol to phthalic anhydride used in the esterification reaction of the present invention is relatively small, while ensuring the conversion rate of diisononyl phthalate, the amount of isononyl alcohol that is not completely reacted is relatively reduced, thereby reducing the difficulty of separating and recovering isononyl alcohol in subsequent process steps.

[0017] As a preferred embodiment of the present invention, in step S1, the catalyst includes at least one of tetrabutyl titanate, benzenesulfonic acid, sulfuric acid and phosphotungstic acid.

[0018] As a preferred embodiment of the present invention, in step S1, the temperature of the esterification reaction is 150-250° C. (more preferably 180-210° C.), and the time of the esterification reaction is 2-6 h (more preferably 3-4 h).

[0019] As a preferred embodiment of the present invention, the mixture of the catalyst and isononanol is prepared by dissolving the catalyst in isononanol, and the mixture of phthalic anhydride and isononanol is prepared by dissolving phthalic anhydride in isononanol.

[0020] The inventors have found that pre-dissolving the catalyst in isononyl alcohol and pre-dissolving phthalic anhydride in isononyl alcohol is beneficial to improving the efficiency of the esterification reaction, and the heating step of the esterification reaction is simple and does not require staged heating.

[0021] As a preferred embodiment of the present invention, in step S2, the dealcoholization temperature is 170 to 280°C (more preferably 200 to 230°C), and the pressure is -0.05 to -0.2 MPa.

[0022] As a preferred embodiment of the present invention, in step S3, the solution used for the alkali washing is an alkaline solution, the temperature of the alkali washing is 85-95° C., and the time is 1-3 hours.

[0023] Furthermore, the alkaline solution is a sodium hydroxide aqueous solution, and the mass concentration of the sodium hydroxide aqueous solution is 3-5wt%.

[0024] Furthermore, the molar ratio of phthalic anhydride in step S2 to the sodium hydroxide in the alkaline solution in step S3 is 1:1.

[0025] As a preferred embodiment of the present invention, in step S4, the volume ratio of the water used for the water washing to the alkali washing product is 1:(1-3); the temperature of the water washing is 85-95°C, and the time is 1-3h.

[0026] As a preferred embodiment of the present invention, in step S5, the temperature of the separation and purification is 170-280°C (more preferably 200-230°C), and the pressure is 0.02-0.05 MPa.

[0027] As a preferred embodiment of the present invention, in step S6, the drying temperature is 200-300°C (more preferably 250-270°C), and the pressure is 0.05-0.2 MPa.

[0028] In a second aspect, the present invention provides a skid-mounted diisononyl phthalate synthesis device, comprising a first storage tank, a second storage tank, an esterification reactor, a first delivery pump, a dealcoholization tower, a second delivery pump, an alkali washing reactor, a third delivery pump, a water washing reactor, a separation tower and a drying tower integrated and installed on the same base; the first storage tank is used to hold a mixture of catalyst and isononyl alcohol, and the second storage tank is used to hold a mixture of isononyl alcohol and phthalic anhydride; the first storage tank is connected to the feed port of the esterification reactor by a pipeline, and the second storage tank is connected to the feed port of the esterification reactor by a pipeline. Another feed port of the esterification reactor is connected through a pipeline, the bottom discharge port of the esterification reactor is connected to the feed port of the dealcoholization tower through a pipeline and a first delivery pump, the bottom discharge port of the dealcoholization tower is connected to the feed port of the alkali washing reactor through a pipeline and a second delivery pump, the discharge port of the alkali washing reactor is connected to the feed port of the water washing reactor through a pipeline and a third delivery pump, the discharge port of the water washing reactor is connected to the feed port of the separation tower through a pipeline, and the bottom outlet of the separation tower is connected to the feed port of the drying tower through a pipeline.

[0029] The present invention integrates and installs various devices on the same base to form a skid-mounted synthesis device, which is convenient for installation, occupies a small area, and is easy to move.

[0030] As a preferred embodiment of the present invention, the top outlet of the dealcoholization tower is sequentially connected to the first heat exchanger and the recovery tank through a pipeline, and the outlet of the recovery tank is connected to the inlet of the first storage tank through a pipeline. The dealcoholization tower evaporates the low-boiling point components in the crude esterification product from the top of the tower, and the distillate is condensed in sections through the first heat exchanger, and the isononanol can be selectively collected into the recovery tank, and the isononanol in the recovery tank can flow into the first storage tank 1 through a pipeline for recycling and reuse.

[0031] As a preferred embodiment of the present invention, the top outlet of the separation tower is sequentially connected to a fourth delivery pump and a second heat exchanger through a pipeline, and the second heat exchanger is connected to the first storage tank through a pipeline. Under the action of the fourth delivery pump, the effluent discharged from the top of the separation tower enters the second heat exchanger for segmented condensation, and the condensed isononanol is selectively input into the first storage tank for recycling.

[0032] As a preferred embodiment of the present invention, the discharge port of the drying tower is sequentially connected to a fifth delivery pump, a third heat exchanger and a third storage tank through pipelines.

[0033] In the present invention, the synthesis method of diisononyl phthalate described in the first aspect is implemented by the skid-mounted diisononyl phthalate synthesis device described in the second aspect.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The present invention directly mixes a mixture of a catalyst and isononyl alcohol and a mixture of phthalic anhydride and isononyl alcohol for esterification reaction, the esterification reaction efficiency is high, the process operation is simpler, and the prepared diisononyl phthalate has high purity, low acid value, and low viscosity, and can be used as a plasticizer in PVC products;

[0036] (2) The molar ratio of isononyl alcohol to phthalic anhydride used in the esterification reaction of the present invention is relatively small, while ensuring the conversion rate of diisononyl phthalate, the amount of isononyl alcohol that is not completely reacted is relatively reduced, thereby reducing the difficulty of separating and recovering isononyl alcohol in subsequent process steps;

[0037] (3) The present invention integrates and installs various devices on the same base to form a skid-mounted synthesis device, which is convenient for installation, occupies a small area, and is easy to relocate. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic structural diagram of the skid-mounted diisononyl phthalate synthesis device provided by the present invention.

[0039] In the figure, 1-first storage tank, 2-second storage tank, 3-esterification reactor, 4-first delivery pump, 5-dealcoholization tower, 6-first heat exchanger, 7-recovery tank, 8-second delivery pump, 9-alkali washing reactor, 10-third delivery pump, 11-water washing reactor, 12-separation tower, 13-fourth delivery pump, 14-second heat exchanger, 15-drying tower, 16-fourth delivery pump, 17-third heat exchanger, 18-third storage tank. DETAILED DESCRIPTION

[0040] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0041] Unless otherwise specified, the materials and reagents used in the examples can be obtained from commercial sources.

[0042] Example 1

[0043] This embodiment provides a skid-mounted diisononyl phthalate synthesis device, the structure of which is as follows: Figure 1 shown.

[0044] The skid-mounted diisononyl phthalate synthesis device comprises a first storage tank 1, a second storage tank 2, an esterification reactor 3, a first delivery pump 4, a dealcoholization tower 5, a first heat exchanger 6, a recovery tank 7, a second delivery pump 8, an alkali washing reactor 9, a third delivery pump 10, a water washing reactor 11, a separation tower 12, a fourth delivery pump 13, a second heat exchanger 14, a drying tower 15, a fifth delivery pump 16, a third heat exchanger 17 and a third storage tank 18, which are integrated and installed on the same base. This integrated installation forms a skid-mounted synthesis device, which is convenient for installation, occupies a small area and is easy to relocate.

[0045] The first storage tank 1 is used to hold a mixture of a catalyst and isononanol, and the second storage tank 2 is used to hold a mixture of isononanol and phthalic anhydride; the first storage tank 1 is connected to the feed port of the esterification reaction kettle 3 through a pipeline, the second storage tank 2 is connected to another feed port of the esterification reaction kettle 3 through a pipeline, the bottom discharge port of the esterification reaction kettle 3 is connected to the middle feed port of the dealcoholization tower 5 through a pipeline and a first delivery pump 4, the top outlet of the dealcoholization tower 5 is connected to the inlet of the recovery tank 7 through a pipeline and a first heat exchanger 6, and the outlet of the recovery tank 7 is connected to the inlet of the first storage tank 1 through a pipeline. In actual use, the materials in the first storage tank 1 and the second storage tank 2 flow into the esterification reactor 3 through the pipeline for esterification reaction. Under the action of the first delivery pump 4, the crude esterification product enters the dealcoholization tower. The dealcoholization tower 5 evaporates the low-boiling point components in the crude esterification product from the top of the tower. The distillate is condensed in sections through the first heat exchanger 4, and the isononanol is collected into the recovery tank 7. The isononanol in the recovery tank 7 can flow into the first storage tank 1 through the pipeline for recycling and reuse. After dealcoholization, the crude diisononyl phthalate product flows out from the bottom outlet of the dealcoholization tower 5.

[0046] The bottom discharge port of the dealcoholization tower 5 is connected to the feed port of the alkali washing reactor 9 through a pipeline and a second delivery pump 8, the discharge port of the alkali washing reactor 9 is connected to the feed port of the water washing reactor 11 through a pipeline and a third delivery pump 10, the discharge port of the water washing reactor 11 is connected to the middle feed port of the separation tower 12 through a pipeline, and the top outlet of the separation tower 12 is connected to the inlet of the first storage tank 1 through a pipeline, a fourth delivery pump 13 and a second heat exchanger 14. In actual use, under the action of the second delivery pump 8, the crude product flowing out from the bottom outlet of the dealcoholization tower 5 enters the alkali washing reactor 9 for alkali washing, under the action of the third delivery pump 10, the crude product after alkali washing enters the water washing reactor 11 for water washing, and the crude product after water washing enters the separation tower 12 for separation and purification, and the light components (such as water vapor and isononanol, etc.) escape from the top of the separation tower 12, and the purified crude product flows out from the bottom outlet of the separation tower 12. Under the action of the fourth delivery pump 13, the effluent enters the second heat exchanger 14 for segmented condensation, and the condensed isononanol is selectively input into the first storage tank 1 for recycling and reuse.

[0047] The bottom outlet of the separation tower 12 is connected to the middle feed port of the drying tower 15 through a pipeline, and the top outlet of the drying tower 15, the fifth delivery pump 16, the third heat exchanger 17, and the third storage tank 18 are sequentially connected through pipelines. The purified crude product enters the drying tower 15 for drying, and the dried product is extracted from the drying tower 15 by the fifth delivery pump 16 and input into the third heat exchanger 17 for heat exchange cooling to obtain a refined product, and finally the refined product is stored in the third storage tank 18.

[0048] In this embodiment, each pipeline is provided with a flow meter and a control valve (not shown in the figure), and the flow meter is used to control the flow rate of the fluid flowing through.

[0049] In this embodiment, the esterification reaction kettle 3, the alkali washing reaction kettle 9 and the water washing reaction kettle 11 are respectively equipped with a stirring mechanism. During the esterification reaction, alkali washing and water washing processes, the stirring mechanism is started for stirring, and the stirring rate can be 100-500 rpm.

[0050] Example 2

[0051] This embodiment provides a method for synthesizing diisononyl phthalate (DINP), which is implemented by the skid-mounted diisononyl phthalate synthesis device provided in Example 1.

[0052] The synthesis method of diisononyl phthalate comprises the following steps:

[0053] S1, dissolving tetrabutyl titanate in isononanol to obtain a mixture of tetrabutyl titanate and isononanol, and storing the mixture in a first storage tank 1; dissolving phthalic anhydride in isononanol to obtain a mixture of phthalic anhydride and isononanol, and storing the mixture in a second storage tank 2;

[0054] S2, respectively pumping a mixture of tetrabutyl titanate and isononanol and a mixture of phthalic anhydride and isononanol into an esterification reaction kettle 3 for esterification reaction, wherein the mass ratio of tetrabutyl titanate to phthalic anhydride in the esterification reaction kettle 3 is 0.0003:1, and the molar ratio of isononanol to phthalic anhydride is 2:1, and reacting at 180° C. for 3 h (i.e., the esterification reaction temperature is 180° C., and the esterification reaction time is 3 h), to obtain a crude esterification reaction product;

[0055] S3, using the first delivery pump 4 to pump the crude product of the esterification reaction obtained in step S2 into the dealcoholization tower 5, the temperature in the dealcoholization tower 5 is 200° C., the pressure is -0.093 MPa, the low-boiling component is evaporated from the top outlet of the dealcoholization tower 5 to obtain a distillate, and the crude diisononyl phthalate product is discharged from the bottom outlet of the dealcoholization tower 5; the obtained distillate is collected by segmented condensation through the first heat exchanger 6, and the recovered isononanol is collected into a recovery tank 7, and then put into the first storage tank 1 for recycling;

[0056] S4, using a second delivery pump 8 to pump the crude diisononyl phthalate product obtained in step S3 into an alkali washing reactor 9 for alkali washing, wherein the alkali washing solution is a sodium hydroxide aqueous solution (mass concentration is 3wt%), the alkali washing temperature is 90° C., the alkali washing time is 2h, and the molar ratio of the phthalic anhydride to the sodium hydroxide in the alkaline solution is 1:1, to obtain an alkali washing product;

[0057] S5, using a third delivery pump 10 to pump the alkali-washed product obtained in step S4 into a water-washing reactor 11 for water washing, wherein the volume ratio of water used for water washing to the alkali-washed product is 1:1; the water washing temperature is 90° C., and the time is 2 h, to obtain a water-washed product;

[0058] S6, inputting the washed product obtained in step S5 into a separation tower 12 for separation and purification, wherein the temperature in the separation tower 12 is 200° C. and the pressure is 0.043 MPa, and the light component escapes from the top outlet of the separation tower 12, and the purified crude product flows out from the bottom outlet of the separation tower 12; the escaped light component is condensed in sections through a second heat exchanger 14, and the condensed isononanol is recovered into the first storage tank 1;

[0059] S7. The crude product purified in step S6 is input into a drying tower 15 for drying. The temperature in the drying tower 15 is 250° C. and the pressure is 0.1 MPa. The dried product is pumped into a third heat exchanger 17 by a fifth delivery pump 16 for heat exchange cooling to obtain a refined product. The refined product is stored in a third storage tank 18.

[0060] Embodiment 3-4

[0061] Examples 3 and 4 respectively provide a method for synthesizing diisononyl phthalate. The difference between Examples 3 and 4 and Example 2 is that:

[0062] In Example 3, tetrabutyl titanate was not used, but an equal amount of benzenesulfonic acid was used instead;

[0063] In Example 4, tetrabutyl titanate is not used, but an equal mass of phosphotungstic acid is used instead.

[0064] Examples 5 to 9 and Comparative Example 1

[0065] Examples 5 to 9 and Comparative Example 1 respectively provide a method for synthesizing diisononyl phthalate. The differences between Examples 5 to 9 and Comparative Example 1 and Example 2 are:

[0066] Example 5 In step S2, the molar ratio of isononanol to phthalic anhydride is 2.5:1;

[0067] Example 6 In step S2, the molar ratio of isononyl alcohol to phthalic anhydride is 3:1;

[0068] Example 7 In step S2, the molar ratio of isononyl alcohol to phthalic anhydride is 4:1;

[0069] Example 8 In step S2, the molar ratio of isononanol to phthalic anhydride is 1:1;

[0070] Example 9 In step S2, the molar ratio of isononanol to phthalic anhydride is 1.5:1;

[0071] Comparative Example 1 In step S2, the molar ratio of isononanol to phthalic anhydride is 6:1.

[0072] Embodiments 10 to 15

[0073] Examples 10 to 15 respectively provide a method for synthesizing diisononyl phthalate. The difference between Examples 10 to 15 and Example 2 is that:

[0074] Example 10 In step S2, the esterification reaction temperature is 150° C. and the time is 2 h;

[0075] Example 11 In step S2, the esterification reaction temperature is 180° C. and the time is 2 h;

[0076] Example 12 In step S2, the esterification reaction temperature is 180° C. and the time is 4 h;

[0077] Example 13 In step S2, the esterification reaction temperature is 210° C. and the time is 4 h;

[0078] Example 14 In step S2, the esterification reaction temperature is 210° C. and the time is 6 h;

[0079] In Example 15, in step S2, the temperature of the esterification reaction is 250° C. and the time is 3 h.

[0080] Example 16

[0081] This embodiment provides a method for synthesizing diisononyl phthalate. The difference between this embodiment and embodiment 2 is that:

[0082] In step S2 of this embodiment, the mass ratio of the catalyst to phthalic anhydride is 0.04%:1;

[0083] In step S3, the temperature in the dealcoholization tower 5 is 170°C and the pressure is -0.2MPa;

[0084] In step S4, the solution used for alkali washing is a sodium hydroxide aqueous solution (mass concentration is 5wt%), the alkali washing temperature is 85°C, the alkali washing time is 3h, and the molar ratio of the phthalic anhydride to the sodium hydroxide in the alkaline solution is 1:1;

[0085] In step S5, the volume ratio of water used for water washing to the alkali washing product is 1:1; the water washing temperature is 95° C. and the time is 3 hours;

[0086] In step S6, the temperature in the separation tower 12 is 170°C and the pressure is 0.02 MPa;

[0087] In step S7, the temperature in the drying tower 15 is 200°C and the pressure is 0.15 MPa.

[0088] Embodiment 17

[0089] This embodiment provides a method for synthesizing diisononyl phthalate. The difference between this embodiment and embodiment 2 is that:

[0090] In step S2 of this embodiment, the mass ratio of the catalyst to phthalic anhydride is 0.05:1;

[0091] In step S3, the temperature in the dealcoholization tower 5 is 230°C and the pressure is -0.15MPa;

[0092] In step S4, the solution used for alkali washing is a sodium hydroxide aqueous solution (mass concentration is 4 wt%), the alkali washing temperature is 95° C., the alkali washing time is 1 h, and the molar ratio of the catalyst to the sodium hydroxide in the alkaline solution is 1:1;

[0093] In step S5, the volume ratio of water used for water washing to the alkali washing product is 1:2; the water washing temperature is 95° C. and the time is 3 hours;

[0094] In step S6, the temperature in the separation tower 12 is 230°C and the pressure is 0.035 MPa;

[0095] In step S7, the temperature in the drying tower 15 is 270°C and the pressure is 0.12 MPa.

[0096] Embodiment 18

[0097] This embodiment provides a method for synthesizing diisononyl phthalate. The difference between this embodiment and embodiment 2 is that:

[0098] In step S3 of this embodiment, the temperature in the dealcoholization tower 5 is 250° C. and the pressure is -0.07 MPa;

[0099] In step S6, the temperature in the separation tower 12 is 250°C and the pressure is 0.06MPa;

[0100] In step S7, the temperature in the drying tower 15 is 300°C and the pressure is 0.2 MPa.

[0101] Embodiment 19

[0102] This embodiment provides a method for synthesizing diisononyl phthalate. The difference between this embodiment and embodiment 2 is that:

[0103] In step S3 of this embodiment, the temperature in the dealcoholization tower 5 is 280° C. and the pressure is -0.05 MPa;

[0104] In step S6, the temperature in the separation tower 12 is 280°C and the pressure is 0.08 MPa;

[0105] In step S7, the temperature in the drying tower 15 is 300°C and the pressure is 0.2 MPa.

[0106] Comparative Example 2

[0107] This comparative example provides a method for synthesizing diisononyl phthalate (DINP). The difference between this comparative example and Example 2 is that:

[0108] The device used in this comparative example also includes a catalyst storage tank, which is connected to the esterification reaction kettle 3. In step S1, isononanol is stored in the first storage tank 1, and phthalic anhydride is stored in the second storage tank 2;

[0109] In step S2, isononanol and phthalic anhydride are introduced into the esterification reaction kettle 3 at a molar ratio of 2:1. After the temperature is raised to 180°C, tetrabutyl titanate is introduced into the esterification reaction kettle 3 at 180°C. The mass ratio of tetrabutyl titanate to phthalic anhydride is 0.0003:1. The temperature is raised to 225°C and the reaction is kept warm for 3 hours.

[0110] Effect Example 1

[0111] The refined products obtained from the embodiments and comparative examples were used as test samples for testing. The test results are shown in Table 1. The test method is:

[0112] (1) Prepare a standard solution of Pt as a comparative solution, place the sample in a colorimetric tube, and measure the chromaticity using a colorimeter;

[0113] (2) Test the viscosity of each sample using a rotational viscometer at 25°C;

[0114] (3) Prepare 0.1 mol / L KOH standard solution and detect the acid value of the sample by titration;

[0115] (4) Test the flash point of the sample using the Cleveland open cup method of GB / T 1671-2008;

[0116] (5) The volume resistivity of the sample was measured according to the volume resistivity determination method of GB / T 1672-1988, and the DC voltage was 300 V;

[0117] (6) The purified products obtained in each embodiment and comparative example were quantitatively and qualitatively analyzed by liquid chromatography ultraviolet detector. The chromatographic separation conditions were as follows: the chromatographic column was Agilent ZORBAX SB-C18 5 μm (4.6 mm×150 mm); the mobile phase was HPLC methanol; the flow rate was 1.5 mL / min; the injection volume was 5 μL; the column temperature was 30° C.; and the ultraviolet detection wavelength was 207 nm. The mass percentage of DINP in the sample was obtained by quantitative and qualitative analysis, that is, the purity shown in Table 1.

[0118] Table 1

[0119]

[0120]

[0121] Compared with Examples 3 to 4, the purity of DINP in the product prepared in Example 2 is higher, reaching 99.8%, and the volume resistivity and flash point of the product are significantly higher, which indicates that the efficiency of tetrabutyl titanate in catalyzing the esterification of phthalic anhydride is higher.

[0122] Compared with Example 2 and Examples 5 to 9, the molar ratio of isononanol to phthalic anhydride in step S2 of Comparative Example 1 is too high, which affects the completeness of the reaction, thereby reducing the purity of DINP in the product, and further affecting the electrical insulation performance and operating temperature range of the product.

[0123] It can be seen from Example 2 and Examples 10 to 15 that when the esterification reaction temperature is higher than 180°C, the purity of diisononyl phthalate in the product is not significantly improved by continuing to increase the esterification reaction temperature or prolonging the esterification reaction time. Instead, the flash point of the product is reduced. The purity of DINP in the product obtained in Example 2 and Examples 12 to 13 is above 99%, the chromaticity is lower than 25, the product viscosity is low, and the volume resistivity is 40*10 11 Ω·cm or more, and the flash point is above 240°C. Therefore, during the esterification reaction in step S2, the temperature is controlled at 180-210°C and the time is controlled at 3-4h. This can not only obtain DINP products with high purity, low viscosity, a wide operating temperature range and excellent electrical insulation performance, but also reduce energy consumption and maintain high production efficiency.

[0124] Compared with Comparative Example 2, in the embodiment of the present invention, a mixture of tetrabutyl titanate and isononanol and a mixture of phthalic anhydride and isononanol are simultaneously added into an esterification reaction kettle for esterification reaction. The esterification reaction efficiency is high, the process operation is simpler, and the purity of diisononyl phthalate in the prepared product is higher, the acid value is lower, the viscosity is lower, the operating temperature range is wider, and the electrical insulation performance is better.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for synthesizing diisononyl phthalate, characterized in that: The steps include: S1, mixing a mixture of a catalyst and isononanol and a mixture of phthalic anhydride and isononanol for esterification reaction to obtain a crude esterification product; S2, dealcoholizing the crude product of the esterification reaction obtained in step S1 to obtain a crude product of diisononyl phthalate; S3, alkali-washing the crude diisononyl phthalate product obtained in step S2 in sequence to obtain an alkali-washed product; S4, washing the alkali washed product obtained in step S3 with water to obtain a washed product; S5, separating and purifying the washed product obtained in step S4; S6, drying the product purified in step S5, and cooling it to obtain a finished product.

2. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S1, the mass ratio of the catalyst to phthalic anhydride is (0.0003-0.0005):1, and the molar ratio of isononyl alcohol to phthalic anhydride is (1-4):

1.

3. The synthetic method of diisononyl phthalate according to claim 1, characterized in that: In step S1, the catalyst includes at least one of tetrabutyl titanate, benzenesulfonic acid, sulfuric acid and phosphotungstic acid.

4. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S1, the temperature of the esterification reaction is 150-250° C., and the time of the esterification reaction is 2-6 hours.

5. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S2, the dealcoholization temperature is 170 to 280°C, and the pressure is -0.05 to -0.2 MPa.

6. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S3, the solution used for the alkali washing is an alkaline solution, the temperature of the alkali washing is 85-95° C., and the time is 1-3 hours.

7. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S5, the temperature of the separation and purification is 170-280° C., and the pressure is 0.02-0.08 MPa.

8. The method for synthesizing diisononyl phthalate according to claim 1, wherein: In step S6, the drying temperature is 200-300°C and the pressure is 0.05-0.2 MPa.

9. A skid-mounted diisononyl phthalate synthesis device, characterized in that: The invention comprises a first storage tank, a second storage tank, an esterification reactor, a first delivery pump, a dealcoholization tower, a second delivery pump, an alkali washing reactor, a third delivery pump, a water washing reactor, a separation tower and a drying tower which are integrated and installed on the same base; the first storage tank is used to hold a mixture of a catalyst and isononanol, and the second storage tank is used to hold a mixture of isononanol and phthalic anhydride; the first storage tank is connected to the feed port of the esterification reactor through a pipeline, the second storage tank is connected to another feed port of the esterification reactor through a pipeline, the bottom discharge port of the esterification reactor is connected to the feed port of the dealcoholization tower through a pipeline and the first delivery pump, the bottom discharge port of the dealcoholization tower is connected to the feed port of the alkali washing reactor through a pipeline and the second delivery pump, the discharge port of the alkali washing reactor is connected to the feed port of the water washing reactor through a pipeline and the third delivery pump, the discharge port of the water washing reactor is connected to the feed port of the separation tower through a pipeline, and the bottom outlet of the separation tower is connected to the feed port of the drying tower through a pipeline.

10. The skid-mounted diisononyl phthalate synthesis device according to claim 9, characterized in that: The top outlet of the dealcoholization tower is sequentially connected to a first heat exchanger and a recovery tank through a pipeline, and the outlet of the recovery tank is connected to the inlet of the first storage tank through a pipeline; the top outlet of the separation tower is sequentially connected to a fourth delivery pump and a second heat exchanger through a pipeline, and the second heat exchanger is connected to the first storage tank through a pipeline.

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