阅读说明：本技术 一种卤化丁基橡胶的制备方法 (Preparation method of halogenated butyl rubber ) 是由 杨建春 于 2020-06-30 设计创作，主要内容包括：本发明公开一种卤化丁基橡胶的制备方法。该制备方法包括如下步骤：将卤化反应制备的卤化丁基橡胶溶液通过水析凝聚进行处理,得到含有有机溶剂的气体；其中,将所述含有有机溶剂的气体直接或增压后作为氯甲烷分离和精制单元的热源,所述氯甲烷分离和精制单元用于卤化丁基橡胶制备过程中氯甲烷及未反应单体的回收。本发明方法将卤化丁基橡胶溶液水析凝聚得到的含有机溶剂的高温气体直接或增高后用作氯甲烷分离和精制单元的热源,降低了卤化丁基橡胶合成装置的蒸汽消耗,节约了能源。(The invention discloses a preparation method of halogenated butyl rubber. The preparation method comprises the following steps: treating halogenated butyl rubber solution prepared by halogenation reaction through water precipitation condensation to obtain gas containing an organic solvent; wherein, the gas containing the organic solvent is directly used as a heat source of a methyl chloride separation and refining unit or is pressurized and then used for recovering methyl chloride and unreacted monomers in the preparation process of halogenated butyl rubber. The method of the invention uses the high-temperature gas containing the organic solvent obtained by the water precipitation and condensation of the halogenated butyl rubber solution as the heat source of the chloromethane separation and refining unit directly or after being increased, thereby reducing the steam consumption of the halogenated butyl rubber synthesis device and saving the energy.)

1. A preparation method of halogenated butyl rubber is characterized by comprising the following steps: treating halogenated butyl rubber solution prepared by halogenation reaction through water precipitation condensation to obtain gas containing an organic solvent; wherein, the gas containing the organic solvent is directly used as a heat source of a methyl chloride separation and refining unit or is pressurized and then used for recovering methyl chloride and unreacted monomers in the preparation process of halogenated butyl rubber.

2. The production method according to claim 1, wherein the methyl chloride separation and purification unit comprises at least a purified methyl chloride distillation column, a crude methyl chloride distillation column, and an isobutylene recovery column.

3. The production method according to claim 2, wherein the organic solvent-containing gas is used as a heat source for at least one of the bottoms of the fine methyl chloride distillation column, the crude methyl chloride distillation column and the isobutylene recovery column, directly or after being pressurized.

4. The production method according to any one of claims 1 to 3, wherein the temperature of the organic solvent-containing gas is 70 to 150 ℃, preferably 80 to 130 ℃, more preferably 70 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃.

Preferably, the initial pressure of the organic solvent-containing gas is 0.09 to 0.15 MPa.

Preferably, the pressure ratio of the pressurization is 1.1 to 5.

Preferably, said pressurisation is achieved by a compressor.

5. The method according to any one of claims 1 to 4, wherein the halogenated butyl rubber is a chlorinated butyl rubber or a brominated butyl rubber.

6. The process according to any one of claims 1 to 5, wherein said halogenated butyl rubber solution is further coagulated by water precipitation to obtain a mixed system of colloidal particles/water of halogenated butyl rubber.

Preferably, the rubber particle/water mixed system of the halogenated butyl rubber is sent to a rubber post-treatment system to obtain a finished halogenated butyl rubber product.

7. The process according to any one of claims 1 to 6, wherein the aqueous coagulation of the halogenated butyl rubber solution comprises: and (3) contacting the halogenated butyl rubber solution with hot water and/or water vapor to obtain a micelle/water mixed system of the halogenated butyl rubber and gas containing an organic solvent.

Preferably, the temperature of the hot water is 80-120 deg.C, preferably 85-115 deg.C, more preferably 80 deg.C, 85 deg.C, 90 deg.C, 95 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, 115 deg.C, 120 deg.C.

Preferably, the water vapor is 0.2 to 2.0MPa, preferably 0.4 to 1.0MPa, more preferably 0.2MPa, 0.3MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 1.0 MPa.

8. The process according to any one of claims 1 to 7, wherein the halogenated butyl rubber solution is prepared by a process comprising: and (3) dissolving butyl rubber in an organic solvent to obtain a butyl rubber solution, and performing halogenation and neutralization reaction to obtain the halogenated butyl rubber solution.

9. The method according to claim 8, wherein the butyl rubber is obtained by contacting a slurry containing methyl chloride and unreacted monomers from a butyl polymerization reaction with a heat medium.

10. The process according to claim 9, wherein the slurry is contacted with a heat medium to obtain a gas containing methyl chloride, the medium and unreacted monomers, which is fed to a methyl chloride separation and purification unit, the medium is separated, and methyl chloride and the unreacted monomers are recovered.

Technical Field

The invention belongs to the field of rubber preparation, and particularly relates to a preparation method of halogenated butyl rubber.

Background

Halogenated butyl rubbers include chlorinated butyl rubbers and brominated butyl rubbers, which are products obtained by reacting butyl rubbers of a certain degree of saturation with chlorine or bromine in aliphatic hydrocarbon solvents. The industrially popular preparation method comprises the steps of synthesizing butyl rubber by a methyl chloride slurry method, recovering methyl chloride and unreacted monomers, preparing a butyl rubber solution, carrying out halogenation reaction, carrying out water precipitation, condensation and separation on a halogenated butyl rubber solution and the like. Firstly, producing butyl rubber by a methane chloride slurry method: isobutene and a small amount of isoprene are used as reaction monomers, aluminum trichloride is used as a catalyst, methyl chloride is used as a diluent, the concentration of the reaction monomers is 10-20 wt%, polymerization reaction is carried out at a low temperature of about-100 ℃, a polymerization product is suspended in the methyl chloride to form slurry, the formed slurry enters a degassing kettle from an overflow pipe at the top of the polymerization kettle, and butyl rubber, the methyl chloride and unreacted monomers are separated under the action of hot water and steam; recovery of (di) chloromethane and unreacted monomers: wet methyl chloride flashed from a degassing kettle enters a cooler for cooling, gas and condensed water are separated in a liquid separating tank after cooling, gas phase enters a methyl chloride compressor for compression, the compressed gas is cooled, condensed water in the gas is separated, then the wet methyl chloride gas containing saturated water is sent into an activated alumina drying tower for drying, the dried methyl chloride gas with the water content reaching the standard enters a methyl chloride rectifying tower for separating methyl chloride and monomers and returns to a polymerization system for recycling, and the rectifying system comprises a refined methyl chloride rectifying tower, a crude methyl chloride rectifying tower, an isobutylene and isoprene recovery tower and the like; preparation and halogenation of a (tri) butyl rubber solution: chloromethane is not a good solvent of butyl rubber, and the halogenation reaction needs to dissolve butyl rubber in a good solvent (such as n-hexane) to prepare a butyl rubber solution, and then the butyl rubber solution is contacted with chlorine or liquid bromine to prepare halogenated butyl rubber; (IV) water precipitation and coagulation: the obtained halogenated butyl glue solution is neutralized by alkali, enters a water precipitation coagulation separation polymer and a solvent, and recovers unreacted monomers.

The halogenated butyl rubber production device has the defect of high energy consumption, and the research on how to effectively reduce the energy consumption is of great industrial value.

Disclosure of Invention

The invention provides a preparation method of halogenated butyl rubber, which comprises the following steps: treating halogenated butyl rubber solution prepared by halogenation reaction through water precipitation condensation to obtain gas containing an organic solvent; wherein, the gas containing the organic solvent is directly used as a heat source of a methyl chloride separation and refining unit or is pressurized and then used for recovering methyl chloride and unreacted monomers in the preparation process of halogenated butyl rubber.

According to an embodiment of the present invention, the methyl chloride separation and purification unit comprises at least a purified methyl chloride distillation column, a crude methyl chloride distillation column and an isobutene recovery column.

According to an embodiment of the present invention, the organic solvent-containing gas is used as a heat source for at least one of the bottoms of the fine methyl chloride distillation column, the crude methyl chloride distillation column and the isobutylene recovery column, directly or after pressurization.

According to an embodiment of the invention, the temperature of the gas containing the organic solvent is in the range of 70-150 ℃, such as 85-130 ℃, exemplary 70 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃.

According to an embodiment of the invention, the initial pressure of the organic solvent containing gas is between 0.09 and 0.15MPa, such as 0.09MPa, 0.10MPa, 0.11MPa, 0.12MPa, 0.13MPa, 0.14MPa, 0.15 MPa.

According to an embodiment of the invention, the pressure ratio of the pressurization is 1.1 to 5, such as 1.5 to 3, exemplary 1.1, 1.5, 2, 3, 4, 5.

According to an embodiment of the invention, said pressurization is achieved by a compressor.

According to an embodiment of the present invention, the halogenated butyl rubber may be chlorinated butyl rubber or brominated butyl rubber.

According to an embodiment of the invention, said halogenated butyl rubber solution is coagulated by elutriation also resulting in a mixed crumb rubber/water system of halogenated butyl rubber.

Preferably, the aqueous precipitation coagulation of the halogenated butyl rubber solution comprises: and (3) contacting the halogenated butyl rubber solution with hot water and/or water vapor to obtain a micelle/water mixed system of the halogenated butyl rubber and gas containing an organic solvent.

Preferably, the hot water has a temperature of 80-120 deg.C, such as 85-115 deg.C, illustratively 80 deg.C, 85 deg.C, 90 deg.C, 95 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, 115 deg.C, 120 deg.C.

Preferably, the water vapor may be from 0.2 to 2.0MPa (preferably from 0.4 to 1.0MPa, exemplary 0.2MPa, 0.3MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 1.0 MPa).

Preferably, the rubber particle/water mixed system of the halogenated butyl rubber is sent to a rubber post-treatment system to obtain a finished halogenated butyl rubber product.

According to an embodiment of the present invention, the process for preparing the halogenated butyl rubber solution comprises: and (3) dissolving butyl rubber in an organic solvent to obtain a butyl rubber solution, and performing halogenation and neutralization reaction to obtain the halogenated butyl rubber solution.

According to an embodiment of the invention, the butyl rubber is obtained by contacting a slurry containing methyl chloride and unreacted monomers from a butyl polymerization reaction with a heat medium.

Preferably, the temperature of the thermal medium is 150-350 ℃, such as 170-320 ℃, exemplary 150 ℃, 170 ℃, 190 ℃, 210 ℃, 230 ℃, 250 ℃, 270 ℃, 290 ℃, 310 ℃, 330 ℃, 350 ℃.

Preferably, the contacting of the slurry and the thermal medium also results in a gas comprising methyl chloride, the medium and unreacted monomers. For example, the medium comprises liquid water and/or water vapor.

According to an embodiment of the invention, the gas comprising methyl chloride, medium and unreacted monomers is fed to a methyl chloride separation and purification unit, the medium is separated and methyl chloride and unreacted monomers are recovered.

According to a preferred embodiment of the present invention, the process for the preparation of halogenated butyl rubber comprises the following steps: treating halogenated butyl rubber solution prepared by halogenation reaction through water precipitation condensation to obtain gas containing an organic solvent; wherein, the gas containing the organic solvent is directly or after being pressurized to be used as a heat source of at least one part of a reboiler of a tower kettle of a refined chloromethane distillation tower, a crude chloromethane distillation tower and an isobutene recovery tower in a chloromethane separation and refining unit, and the chloromethane separation and refining unit is used for recovering chloromethane and unreacted monomers in the preparation process of the halogenated butyl rubber.

The invention has the beneficial effects that:

the method of the invention directly uses the high-temperature gas containing the organic solvent obtained by the water precipitation and condensation of the halogenated butyl rubber solution as the heat source of the chloromethane separation and refining unit or after pressurization, thereby reducing the steam consumption of the halogenated butyl rubber synthesis device and saving the energy.

Drawings

FIG. 1 is a schematic flow chart of the preparation of brominated butyl rubber of example 1.

FIG. 2 is a schematic flow chart of the preparation of brominated butyl rubber of example 2.

Reference numerals: v, a condensation kettle, T3, a crude chloromethane tower, T4, an isobutene recovery tower, B3, a crude chloromethane tower reboiler, B4, an isobutene recovery tower reboiler, K, a compressor, 1, a brominated butyl rubber n-hexane solution, 2, hot water, 3, water vapor, 4, n-hexane-containing gas, 5, a mixture of brominated butyl rubber particles and water, 6, pressurized n-hexane-containing gas, 7, a condensate, 23 crude chloromethane tower feeding, 31, crude chloromethane tower reflux, 32, crude chloromethane, 33, crude chloromethane tower kettle liquid, 34, an isobutene recovery tower top gas phase, 35 and isobutene recovery tower kettle liquid.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.