Method for preparing tetracyclododecene from C9 and norbornene

Abstract

The invention provides a method for preparing tetracyclododecene by taking C9 and norbornene as raw materials, which comprises the following steps: firstly, sufficiently mixing the norbornene and the C9 raw material in a mixer, then feeding into a reaction kettle, heating and reacting; the method comprises the following steps: enabling cyclopentadiene obtained by decomposing a dicyclopentadiene component in C9 at a high temperature to react with norbornene to generate a tetracyclododecene product, and subsequently preparing the high-purity tetracyclododecene product through three-section rectification operation.

Description

Technical Field

[0001] The present invention relates to the field of synthesis of cycloolefin monomers, and particularly to a method for preparing tetracyclododecene from C9 and norbornene. Background Art

[0002] Cycloolefin copolymer (COC) has characteristics such as high transparency, heat resistance, chemical stability, and moisture resistance, so it has a wide range of applications in fields such as packaging, medical, optics, and intelligent devices. Currently, norbornene is mostly used as the cycloolefin monomer in the preparation raw materials of COC. Research shows that if cycloolefin monomers with greater steric hindrance are used, COC can have a higher glass transition temperature and stronger toughness at a lower cycloolefin insertion rate. The COC product synthesized by Mitsui Chemicals in Japan using tetracyclododecene as the cycloolefin monomer has more excellent optical properties and wider applications compared with other COCs.

[0003] Patent US4320239 mentions a process for preparing norbornene and tetracyclododecene by reacting olefins, norbornene, and cyclopentadiene, and a product with a molar ratio of norbornene to tetracyclododecane in the range of 95 / 5 to 5 / 95 can be obtained. Patent JP2008247850A mentions a process for preparing tetracyclododecene from ethylene, norbornene, and dicyclopentadiene, and a high-purity tetracyclododecene product is obtained by rectification. Patent CN112592248A mentions a process for preparing tetracyclododecene using norbornene and dicyclopentadiene as raw materials. Patent CN115433053A introduces a method for co-producing norbornene and tetracyclododecene using ethylene and dicyclopentadiene as raw materials.

[0004] In previous various processes, the purity of dicyclopentadiene used as the raw material for preparing tetracyclododecene is mostly above 80%, and the purity requirement of some processes even reaches 95%. This requires purchasing externally or obtaining the required dicyclopentadiene raw material through refining, greatly increasing the raw material cost. C9 fraction contains a large amount of dicyclopentadiene, and because it is a by-product of olefin cracking, its cost is low. If the dicyclopentadiene in C9 can be utilized and used as the raw material for tetracyclododecene, the production cost of tetracyclododecene can be greatly reduced. Summary of the Invention

[0005] Aiming at the problem of the high cost of the dicyclopentadiene raw material used in the above-mentioned prior art, the present invention provides a method for preparing tetracyclododecene from C9 and norbornene, and a high-purity tetracyclododecene product can be prepared.

[0006] A method for preparing tetracyclododecene from C9 and norbornene provided by the present invention includes the following steps:

[0007] S1. The norbornene and the carbon nine raw material are fully mixed in a mixer, and then sent to a reactor for reaction; wherein the ratio of the molar amount of norbornene added in the mixer to the molar amount of dicyclopentadiene in the carbon nine raw material is (10-25):1;

[0008] S2. The product after the reaction in step S1 is sent to a first distillation tower. After distillation in the first distillation tower, the top product of the first distillation tower is sent to a second distillation tower, and the bottom product of the first distillation tower is sent to a third distillation tower;

[0009] S3. After distillation in the second distillation tower, the light components are separated from the top of the second distillation tower, the heavy components are separated from the bottom of the tower, and the component whose main component is norbornene is taken out from the side line and returned to the mixer;

[0010] S4. The third distillation tower adopts vacuum distillation. After distillation in the third distillation tower, tetracyclododecene product is obtained from the top of the third distillation tower, and high-boiling by-products are separated from the bottom of the tower.

[0011] Furthermore, in step S1, the mass content of norbornene is ≥99%; the mass content of dicyclopentadiene in the carbon nine raw material is ≥30%; and the ratio of the molar amount of norbornene added in the mixer to the molar amount of dicyclopentadiene in the carbon nine raw material is 15:1.

[0012] In step S1, the mixer speed is 500-2200 r / min, the stirring and mixing time is 10-90 min; the reaction temperature in the reactor is 150° C.-250° C., the reaction time is 10 min-120 min, and the reaction pressure is 1.0-2.0 MPa.

[0013] In step S1, the crude product obtained by the reaction is sent to a first distillation tower for separation operation.

[0014] In step S2, the first distillation tower is atmospheric distillation, the tower top temperature is 120°C to 150°C, and the tower bottom temperature is 180°C to 200°C.

[0015] In step S3, the second distillation tower is atmospheric distillation, the tower top temperature is 70°C to 85°C, the tower bottom temperature is 110°C to 125°C, and norbornene is obtained from the side line at a distillation section temperature of 94°C to 98°C.

[0016] In step S4, the third distillation tower is a vacuum distillation, the top pressure is set to 0.2-0.6 kPa, the top temperature is set to 65-135°C, the bottom pressure is set to 1-15 kPa, and the bottom temperature is set to 90-160°C.

[0017] In summary, the present invention provides a process for preparing cyclododecatriene using C9 and norbornene as raw materials. First, norbornene and the C9 raw material are fully mixed in a mixer and then sent to a reaction kettle for heating and reaction. The cyclopentadiene obtained by the decomposition of the dicyclopentadiene component in C9 at high temperature reacts with norbornene to form the cyclododecatriene product. The product obtained from the reaction is first separated in a first distillation column, and the overhead product is further separated in a second distillation column. The norbornene obtained from the side stream can be returned to the mixer to continue participating in the reaction; the bottom product of the first distillation column is sent to a third distillation column, and high-purity cyclododecatriene product is obtained at the top of the third distillation column, and high-boiling substances are separated at the bottom.

[0018] Compared with the prior art, the technical effects of the present invention are as follows:

[0019] (1) The process provided by the present invention omits the purchase and refining process of dicyclopentadiene. Using C9 as the source of dicyclopentadiene, the content of dicyclopentadiene in the C9 fraction is low, the impurities are more complex, and it is a by-product of olefin cracking. Therefore, the price is lower, greatly reducing the raw material cost.

[0020] (2) The raw materials of the present invention are only the C9 fraction and norbornene. Moreover, in the case where the content of dicyclopentadiene in the C9 fraction is low and the impurities are more complex, through process optimization, a high-purity cyclododecatriene product is obtained.

[0021] (3) In order to ensure the qualified purity of the cyclododecatriene product, the present invention adopts a three-stage distillation method in the distillation section. In the first distillation column, the unreacted C9 components and excessive norbornene are separated from the cyclododecatriene and high-boiling substances. In the second distillation column, norbornene is recovered, and a high-purity cyclododecatriene product is obtained in the third distillation column. Considering that there are more impurities and more complex components in the raw materials in the present invention, it is creatively proposed to first separate the light components containing norbornene from the heavy components containing cyclododecatriene in the first distillation column, and then recover norbornene and refine cyclododecatriene respectively.

[0022] In summary, the present invention provides a process for preparing cyclododecatriene using C9 and norbornene as raw materials, and adopts a three-stage distillation scheme in distillation to purify cyclododecatriene. This process not only greatly reduces the raw material cost, but also can improve the purity of the cyclododecatriene product. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic process flow diagram for synthesizing cyclododecatriene of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention, it should be understood that other embodiments may be achieved and various changes may be made to the present invention without departing from the spirit and scope of the present invention. The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] In the examples and comparative examples of the present invention, an Agilent GC 7588 gas chromatograph was used to determine the components of substances.

[0026] Example 1

[0027] S1: The content of dicyclopentadiene in the C9 components of the raw material is 31.84%, and the content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the C9 raw material in the mixer is 15:1. After mixing in the mixer for 15 minutes, it is sent into the reaction kettle for reaction. Among them, the rotation speed of the mixer is 1800 r / min. The reaction pressure is set at 1.2 MPa, the reaction temperature is 170 °C, and the reaction residence time is 30 minutes.

[0028] S2. The product after the reaction in step S1 is sent to the first distillation column. After distillation in the first distillation column, the overhead product of the first distillation column is sent to the second distillation column, and the bottom product of the first distillation column is sent to the third distillation column; among them, the set temperature at the top of the first distillation column is 130 °C, and the set temperature at the bottom is 190 °C.

[0029] S3. After distillation in the second distillation column, light components are separated from the top of the second distillation column, heavy components are separated from the bottom, and the component with the main component of norbornene is side-drawn and returned to the mixer; among them, the set temperature at the top of the second distillation column is 70 °C, the set temperature at the bottom is 115 °C, and norbornene is obtained at the side line at a temperature of 94 °C - 98 °C in the rectifying section.

[0030] S4. The third distillation column uses vacuum distillation. After distillation in the third distillation column, the product of tetracyclododecene is obtained from the top of the third distillation column, and high-boiling substances are separated from the bottom; among them, the third distillation column is a vacuum distillation column, the set pressure at the top is 0.3 kPa, the set temperature is 95 °C, the set pressure at the bottom is 10 kPa, the set temperature is 160 °C, tetracyclododecene is produced at the top, and high-boiling by-products are obtained at the bottom.

[0031] From the gas chromatographic analysis results, the conversion rate of dicyclopentadiene is 94%, the purity of the tetracyclododecene product is 99%, and the yield is 86%.

[0032] Example 2

[0033] S1: The content of dicyclopentadiene in the C9 components of the raw material is 31.84%, and the mass content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the mixer is 25:1. After mixing in the mixer for 15 minutes, it is sent into the reaction kettle for reaction. Among them, the rotation speed of the mixer is 2200 r / min. The reaction pressure is set at 1.2 MPa, the reaction temperature is 170 °C, and the reaction residence time is 30 minutes.

[0034] Steps S2 - S4 are the same as those in Example 1, but the experimental parameters are different. Specifically: The set temperature at the top of the first distillation column is 145 °C, and the set temperature at the bottom of the column is 190 °C. The set temperature at the top of the second distillation column is 70 °C, and the set temperature at the bottom of the column is 115 °C. Norbornene is obtained from the side line at the rectifying section where the temperature is 94 °C - 98 °C. The third distillation column is a vacuum distillation. The set pressure at the top is 0.3 kPa, the set temperature is 95 °C, the set pressure at the bottom is 10 kPa, and the set temperature is 160 °C. Tetracyclododecene is produced at the top, and high-boiling by-products are obtained at the bottom.

[0035] From the gas chromatography analysis results, the conversion rate of dicyclopentadiene is 97%, the purity of the tetracyclododecene product is 99%, and the yield is 91%.

[0036] Example 3

[0037] S1: The content of dicyclopentadiene in the C9 components of the raw material is 31.84%, and the content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the mixer is 15:1. After mixing in the mixer for 15 minutes, it is sent into the reaction kettle for reaction. Among them, the rotation speed of the mixer is 1000 r / min. The reaction pressure is set at 1.0 MPa, the reaction temperature is 170 °C, and the reaction residence time is 90 minutes.

[0038] Steps S2 - S4 are the same as those in Example 1, but the experimental parameters are different. Specifically: The set temperature at the top of the first distillation column is 145 °C, and the set temperature at the bottom of the column is 190 °C. The set temperature at the top of the second distillation column is 70 °C, and the set temperature at the bottom of the column is 115 °C. Norbornene is obtained from the side line at the rectifying section where the temperature is 94 °C - 98 °C. The third distillation column is a vacuum distillation. The set pressure at the top is 0.3 kPa, the set temperature is 95 °C, the set pressure at the bottom is 10 kPa, and the set temperature is 160 °C. Tetracyclododecene is produced at the top, and high-boiling by-products are obtained at the bottom.

[0039] From the gas chromatography analysis results, the conversion rate of dicyclopentadiene is 98%, the purity of the tetracyclododecene product is 99%, and the yield is 80%.

[0040] Example 4

[0041] S1: The content of dicyclopentadiene in the C9 components of the raw material is 31.84%, and the content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the mixer is 15:1. After mixing in the mixer for 90 min, it is sent into the reaction kettle for reaction. Among them, the rotation speed of the mixer is 500 r / min. The reaction pressure is set at 2.0 MPa, the reaction temperature is 150 °C, and the reaction residence time is 10 min.

[0042] Steps S2 - S4 are the same as those in Example 1, but the experimental parameters are different. Specifically: The set temperature at the top of the first distillation column is 150 °C, and the set temperature at the bottom of the column is 200 °C. The set temperature at the top of the second distillation column is 85 °C, and the set temperature at the bottom of the column is 125 °C. Norbornene is obtained from the side line at the rectifying section where the temperature is 94 °C - 98 °C. The third distillation column is a vacuum distillation. The set pressure at the top is 0.6 kPa, the set temperature is 65 °C, the set pressure at the bottom is 15 kPa, and the set temperature is 90 °C. Tetracyclododecene is produced at the top, and high-boiling by-products are obtained at the bottom.

[0043] From the gas chromatography analysis results, the conversion rate of dicyclopentadiene is 87%, the purity of the tetracyclododecene product is 99%, and the yield is 77%.

[0044] Example 5

[0045] S1: The content of dicyclopentadiene in the C9 components of the raw material is 31.84%, and the content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the mixer is 10:1. After mixing in the mixer for 10 min, it is sent into the reaction kettle for reaction. Among them, the rotation speed of the mixer is 1800 r / min. The reaction pressure is set at 1.7 MPa, the reaction temperature is 250 °C, and the reaction residence time is 120 min.

[0046] Steps S2 - S4 are the same as those in Example 1, but the experimental parameters are different. Specifically: The set temperature at the top of the first distillation column is 120 °C, and the set temperature at the bottom of the column is 180 °C. The set temperature at the top of the second distillation column is 80 °C, and the set temperature at the bottom of the column is 110 °C. Norbornene is obtained from the side line at the rectifying section where the temperature is 94 °C - 98 °C. The third distillation column is a vacuum distillation. The set pressure at the top is 0.2 kPa, the set temperature is 135 °C, the set pressure at the bottom is 1 kPa, and the set temperature is 150 °C. Tetracyclododecene is produced at the top, and high-boiling by-products are obtained at the bottom.

[0047] From the gas chromatography analysis results, the conversion rate of dicyclopentadiene is 95%, the purity of the tetracyclododecene product is 99%, and the yield is 87%.

[0048] Comparative Example 1

[0049] S1: The content of dicyclopentadiene in the raw material's C9 fraction is 31.84%, and the content of norbornene is 99%. The molar ratio of norbornene to dicyclopentadiene in the mixer is 3:1. After mixing in the mixer for 15 min, it is fed into the reaction kettle for reaction. The set reaction pressure is 1.2 MPa, the reaction temperature is 170 °C, and the reaction residence time is 30 min.

[0050] Steps S2 - S4 are the same as those in Example 1.

[0051] From the gas chromatography analysis results, the conversion rate of dicyclopentadiene is 73%, the purity of the tetracyclododecene product is 86%, and the yield is 38%.

[0052] The results of all the above examples and comparative examples are shown in Table 1

[0053] Table 1 Reaction parameters and product properties of the examples and comparative examples

[0054]

[0055] It can be seen from Table 1 that within the reaction parameter range of the present invention, the finally obtained tetracyclododecene products can all reach a purity of 99%. Appropriately increasing the molar ratio of norbornene to dicyclopentadiene, raising the temperature, and increasing the pressure can all increase the conversion rate of dicyclopentadiene and the yield of tetracyclododecene.

[0056] By using the method of the present invention, a high-purity (≥99%) tetracyclododecene product can be obtained. The dicyclopentadiene in the raw material comes from the low-cost cracked C9 fraction. In the rectification section, preliminary separation is first carried out to separate the light components mainly composed of norbornene from the heavy components mainly composed of tetracyclododecene, and then refined operations are carried out separately to obtain high-purity norbornene and tetracyclododecene products. Compared with the prior art, the raw material cost is greatly reduced, and there are obvious technical advantages.

[0057] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should all be covered within the protection scope of the present invention.

Claims

1. A method for preparing tetracyclododecene from C9 and norbornene, characterized in that, The following steps are involved: S1. The norbornene and the carbon nine raw material are fully mixed in a mixer, and then sent to a reactor for reaction; wherein the ratio of the molar amount of norbornene added in the mixer to the molar amount of dicyclopentadiene in the carbon nine raw material is (10-25):1; S2. The product after the reaction in step S1 is sent to a first distillation tower. After distillation in the first distillation tower, the top product of the first distillation tower is sent to a second distillation tower, and the bottom product of the first distillation tower is sent to a third distillation tower; S3. After distillation in the second distillation tower, the light components are separated from the top of the second distillation tower, the heavy components are separated from the bottom of the tower, and the component whose main component is norbornene is taken out from the side line and returned to the mixer; S4. The third distillation tower adopts vacuum distillation. After distillation in the third distillation tower, tetracyclododecene product is obtained from the top of the third distillation tower, and high boiling products are separated from the bottom of the tower.

2. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S1, the mass content of norbornene is ≥99%.

3. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S1, the mass content of dicyclopentadiene in the carbon nine raw material is ≥30%.

4. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S1, the ratio of the molar amount of norbornene added into the mixer to the molar amount of dicyclopentadiene in the carbon nine raw material is 15:

1.

5. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S1, the mixer has a rotating speed of 500 to 2200 r / min, and the stirring and mixing time is 10 to 90 min.

6. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S1, the reaction temperature in the reactor is 150°C to 250°C, the reaction time is 10min to 120min, and the reaction pressure is 1.0 to 2.0MPa.

7. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S2, the first distillation tower is atmospheric distillation, the tower top temperature is 120°C to 150°C, and the tower bottom temperature is 180°C to 200°C.

8. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S3, the second distillation tower is atmospheric distillation, the tower top temperature is 70°C to 85°C, the tower bottom temperature is 110°C to 125°C, and norbornene is obtained from the side line at a distillation section temperature of 94°C to 98°C.

9. The method for preparing tetracyclododecene from C9 and norbornene according to claim 1, characterized in that: In step S4, the third distillation tower is a vacuum distillation, the top pressure is set to 0.2-0.6 kPa, the top temperature is set to 65-135°C, the bottom pressure is set to 1-15 kPa, and the bottom temperature is set to 90-160°C.

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