阅读说明：本技术 一种医疗级热塑性弹性体工业化生产装置及生产方法 (Industrial production device and production method for medical-grade thermoplastic elastomer ) 是由 郭方飞 于 2021-09-14 设计创作，主要内容包括：本发明公开了一种医疗级热塑性弹性体工业化生产装置及生产方法,包括反应单元、脱催单元和汽提单元和后处理单元,前续还包括原料精制单元,本发明提供的技术工艺具有极佳的连续性,通过工艺整合调配和工艺参数的控制,使得通过该工艺生产的SEBS产品,1,2丁二烯含量及分子量容易控制,分子量分布窄,加氢度高,灰分含量低,与PP共混透亮、无晶点,满足医疗卫生级SEBS产品要求。(The invention discloses a medical-grade thermoplastic elastomer industrial production device and a production method, which comprise a reaction unit, a catalysis removal unit, a steam stripping unit, a post-treatment unit and a raw material refining unit.)

1. A medical grade thermoplastic elastomer industrial production device is characterized by comprising: the device comprises a reaction unit, a catalyst removal unit, a steam stripping unit and a post-treatment unit;

the reaction unit comprises a raw material tank, a polymerization kettle, a preheater, a first static mixer, a jet mixer, a hydrogenation tower and a flash tank which are connected in sequence; the raw material tank comprises a refined butadiene tank, a refined styrene tank, a refined solvent tank and an auxiliary agent tank; the polymerization kettle is connected with an external circulation condenser; the static mixer is connected with a catalyst tank; the jet mixer is connected with a hydrogen tank; the flash tank comprises a primary flash tank and a secondary flash tank which are sequentially connected, the hydrogenation tower is communicated with the primary flash tank through a pressure reducing valve, the top end of the primary flash tank is communicated with a first condenser, the bottom end of the primary flash tank is communicated with the secondary flash tank through a second pressure reducing valve, the top end of the secondary flash tank is communicated with a second condenser, and the bottom end of the secondary flash tank is communicated with the catalyst removal unit;

the de-catalysis unit comprises a static mixer II, a neutralization kettle and a phase separation tank I which are connected in sequence; the bottom end of the secondary flash tank is communicated with a second static mixer, and the second static mixer is also communicated with a pure water tank and an acid tank; the neutralization kettle is communicated with a demulsifier tank; the phase separation tank is communicated with the sewage treatment system, the static mixer and the stripping unit;

the steam stripping unit is a three-kettle steam stripping system, the discharge of the three-kettle steam stripping system is communicated with a second phase splitting tank, and the glue solution enters the post-treatment unit after the two phases of the glue solution pass through the second phase splitting tank;

the post-treatment unit comprises a dehydrator, a dryer and a grinding mill which are connected in sequence, the two discharge ends of the phase separation tank are communicated with the dehydrator, and the dehydrator is communicated with the three-kettle steam stripping system.

2. The industrial production device of medical grade thermoplastic elastomer as claimed in claim 1, wherein the polymerization kettle is a batch type stirring kettle.

3. The industrial production device for medical grade thermoplastic elastomers according to claim 1, wherein the hydrogenation tower comprises a first cooling section, a first filling section, a second cooling section, a second filling section and a third cooling section which are arranged in sequence from the bottom to the top of the tower.

4. The industrial production device of medical grade thermoplastic elastomer as claimed in claim 1, wherein the three-kettle stripping system comprises a first stripping kettle, a second stripping kettle and a third stripping kettle which are sequentially communicated, the first stripping kettle is fed and communicated with the first phase separation tank and the dehydrator, the bottom ends of the second stripping kettle and the third stripping kettle are respectively communicated with a steam source, the outlet air at the top ends of the second stripping kettle and the third stripping kettle is mixed with the steam source through an injector and then communicated to the bottom end of the first stripping kettle, the top end of the first stripping kettle is communicated with the second phase separation tank through a condenser, the outlet water at one end of the second phase separation tank is communicated with the first stripping kettle, and the solvent at the other end is recovered.

5. The industrial production device of medical grade thermoplastic elastomer as claimed in claim 1, wherein the refined butadiene tank is communicated with a butadiene refining unit, the refined styrene tank is communicated with a styrene refining unit, and the refined solvent tank is communicated with a solvent refining unit;

the butadiene refining unit comprises a first rectifying tower, a first alumina drying tower and a first molecular sieve drying tower which are sequentially connected, the bottom end of the first rectifying tower is connected with a first reboiler, the top end of the first rectifying tower is connected with a third condenser, and the first molecular sieve drying tower is connected with the refined butadiene tank in a discharging mode;

the styrene refining unit comprises a second rectifying tower, a second alumina drying tower and a second molecular sieve drying tower which are sequentially connected, the bottom end of the second rectifying tower is connected with a second reboiler, the top end of the second rectifying tower is connected with a fourth condenser, and the second molecular sieve drying tower is connected with the refined styrene tank in a discharging mode;

the solvent alkene refining unit comprises a rectifying tower III, a solvent hydrogenation tower and a molecular sieve drying tower III which are sequentially connected, the bottom end of the rectifying tower III is connected with a reboiler III, the top end of the rectifying tower III is connected with a condenser V, the solvent hydrogenation tower is connected with a hydrogenation catalyst source, and the discharge end of the molecular sieve drying tower III is connected with the refined solvent tank.

6. A method of making a medical grade thermoplastic elastomer using the device of claims 1-5, comprising the steps of:

the method comprises the following steps: refining of raw materials

Crude butadiene enters a refined butadiene tank after being refined by a butadiene refining unit, crude styrene enters a refined styrene tank after being refined by a styrene refining unit, and a crude solvent enters a refined solvent tank after being refined by a solvent alkene refining unit;

step two: reaction preparation

(2.1) adding refined styrene, a solvent and an auxiliary agent into a polymerization kettle, controlling the temperature of an external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, then adding refined butadiene, controlling the temperature of the external circulation condenser to be less than or equal to 60 ℃, reacting for 30-35min, then adding refined styrene again, controlling the temperature of the external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, finally adding a terminator to finish the reaction, discharging a product, and preparing a block SBS polymer glue solution;

(2.2) preheating the block SBS polymer glue solution to 90 ℃ by a preheater, mixing the block SBS polymer glue solution with a catalyst in a first static mixer, conveying the mixture to a jet mixer for mixing reaction with hydrogen, wherein the addition of the catalyst is 0.01-0.3mmol/100g of the block SBS polymer glue solution and the hydrogen consumption is 30-40 NL/100g of the block SBS polymer glue solution, reacting the mixture in a hydrogenation tower with the pressure of less than or equal to 20bar and the temperature of less than or equal to 140 ℃, sequentially treating the reaction product by a primary flash tank with the pressure of less than or equal to 5bar and the temperature of less than or equal to 120 ℃ and a secondary flash tank with the pressure of less than or equal to 0.1bar and the temperature of less than or equal to 80 ℃, and discharging the bottom of the secondary flash tank to obtain the glue solution;

step three: decatalyst

The glue solution enters a de-catalysis unit, is mixed with acid and pure water through a second static mixer and then enters a neutralization kettle, demulsifier is squeezed into the neutralization kettle, then stirring reaction is completed, the mixture enters a first phase-splitting tank, and the upper glue solution is discharged and enters a stripping unit after phase splitting is performed in the first phase-splitting tank;

step four: stripping

After the glue solution is stripped by adopting a three-kettle stripping system, discharging the glue solution to a post-treatment unit, wherein the volume ratio of circulating hot water to the glue solution is (3-5): 1, stripping by adopting 8barg steam, wherein the volume ratio of the steam to the glue solution is (0.3-0.4): 1;

step five: post-treatment and packaging

And dehydrating the glue solution entering the post-treatment unit by a dehydrator, drying by a dryer, grinding by a grinding mill until the grain diameter is less than or equal to 0.5mm, and packaging to obtain a finished product.

7. The method for preparing a medical grade thermoplastic elastomer according to claim 6, wherein in the first step:

in the butadiene refining unit, the pressure of a rectifying tower I is 3bar, the temperature is 30-40 ℃, the water content of butadiene extracted by the rectifying tower I is less than or equal to 15ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the first pressure of an alumina drying tower is 3bar, the temperature is 30-35 ℃, the water content of the extracted butadiene is less than or equal to 5ppm, and TBC is 0; the pressure of the molecular sieve drying tower is 3bar, the temperature is 30-35 ℃, and the water content of the extracted butadiene is less than or equal to 1 ppm;

the pressure of a second rectifying tower in the styrene refining unit is 5KPa, the temperature is 25-65 ℃, the water content of the styrene extracted by the second rectifying tower is less than or equal to 20ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the second pressure of the alumina drying tower is 3bar, the temperature is 25-30 ℃, the water content of the extracted styrene is less than or equal to 5ppm, and TBC is 0; the pressure of the molecular sieve drying tower II is 3bar, the temperature is 25-30 ℃, and the water content of the extracted styrene is less than or equal to 1 ppm;

the third pressure of a rectifying tower in the solvent refining unit is 1-3bar, the temperature is 90-130 ℃, the water content of the solvent extracted by the third rectifying tower is less than or equal to 15ppm, and the cyclopentadiene content is less than or equal to 20 ppm; the pressure of the solvent hydrogenation tower is 5bar, the temperature is 50-60 ℃, and the extracted solvent cyclopentadiene content is less than or equal to 1 ppm; the three pressures of the molecular sieve drying tower are 3bar, the temperature is 30-40 ℃, and the water content of the extracted solvent is less than or equal to 1 ppm;

the hydrogenation catalyst in the solvent hydrogenation tower is nickel or palladium, and the solvent is one of alkane or cycloalkane.

8. The method for preparing the medical-grade thermoplastic elastomer as claimed in claim 6, wherein the auxiliary agents in the step (2.1) are an initiator, an activator and a structure regulator, and the weight ratio of the refined styrene to the refined butadiene to the solvent is (1-3): (7-9): 90; the mass ratio of the refined styrene added twice is 1: 1; the dosage of the initiator is 0.05-0.1 g/100g of polymer, the dosage of the activator is 0.04-0.08 g/100g of polymer, and the dosage of the structure regulator is 0.03-0.06 g/100g of polymer;

the initiator is one of n-butyl lithium or sec-butyl lithium;

the activating agent is tetrahydrofuran;

the structure regulator is one or two of tetramethyl ethylenediamine, tetrahydrofurfuryl amine and ethylene glycol dibutyl ether;

the terminator is one of water, alcohol or phenols.

9. The method for preparing a medical grade thermoplastic elastomer as claimed in claim 6, wherein the catalyst in step (2.2) is one of an aluminum nickel catalyst, a lithium titanium catalyst and an aluminum titanium catalyst.

10. The method for preparing the medical-grade thermoplastic elastomer according to claim 6, wherein the acid in the step three is one or two of citric acid, neodecanoic acid, diluted hydrochloric acid, diluted sulfuric acid and carbonic acid, and the mass ratio of the glue solution, the acid and the pure water is 1: (0.00005-0.0001): 10.

Technical Field

The invention relates to the technical field of polymer chemical industry, in particular to a device and a method for industrially producing a medical-grade thermoplastic elastomer.

Background

In the field of medical consumables, such as infusion tubes, infusion bags, medical rubber plugs, etc., soft PVC has been used in large quantities. A large amount of phthalate plasticizers are added into the soft PVC, and the phthalate plasticizers are similar to environmental estrogens, can cause potential damage to the reproductive system, the blood system, the nervous system, the kidney system and the gallbladder system of a human body after long-term contact, and have certain teratogenicity and carcinogenicity, so the Reach and RoHS laws of the European Union are strictly controlled in the industries of electronic appliances, toys, clothes, automobile parts, leather making, shoe industry, furniture and the like.

Soft PVC is gradually eliminated, and SEBS is considered as the best substitute of soft PVC and meets new development opportunities. However, the medical SEBS mainly depends on import at present, and a few SEBS manufacturers produce products with low hydrogenation degree, high impurity content and poor transparency, so that the SEBS is mainly used in the fields of medium and low-end wires and coating materials and is difficult to achieve medical application.

Therefore, how to provide a medical-grade SEBS industrial production method and a production system is a problem to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the present invention provides an industrial production apparatus and a production method for medical grade thermoplastic elastomer, which ensure that the product has excellent medical grade performance by combination of processes and optimization of conditions.

In order to achieve the purpose, the invention adopts the following technical scheme:

firstly, a medical grade thermoplastic elastomer industrial production device is provided, which comprises: the device comprises a reaction unit, a catalyst removal unit, a steam stripping unit and a post-treatment unit;

the reaction unit comprises a raw material tank, a polymerization kettle, a preheater, a first static mixer, a jet mixer, a hydrogenation tower and a flash tank which are connected in sequence; the raw material tank comprises a refined butadiene tank, a refined styrene tank, a refined solvent tank and an auxiliary agent tank; the polymerization kettle is connected with an external circulation condenser; the static mixer is connected with a catalyst tank; the jet mixer is connected with a hydrogen tank; the flash tank comprises a primary flash tank and a secondary flash tank which are sequentially connected, the hydrogenation tower is communicated with the primary flash tank through a pressure reducing valve, the top end of the primary flash tank is communicated with a first condenser, the bottom end of the primary flash tank is communicated with the secondary flash tank through a second pressure reducing valve, steam is recovered after the first condenser is treated, a solvent is refined and recycled, the top end of the secondary flash tank is communicated with a second condenser, the bottom end of the secondary flash tank is communicated with the de-catalysis unit, non-condensable gas is removed from a torch after the second condenser is treated, and the solvent is refined and recycled;

the de-catalysis unit comprises a static mixer II, a neutralization kettle and a phase separation tank I which are connected in sequence; the bottom end of the secondary flash tank is communicated with a second static mixer, and the second static mixer is also communicated with a pure water tank and an acid tank; the neutralization kettle is communicated with a demulsifier tank; the phase separation tank is communicated with the sewage treatment system, the static mixer and the steam stripping unit, part of the discharged liquid of the phase separation tank enters the sewage treatment system for treatment, and part of the discharged liquid is recycled and mixed with glue solution, acid and pure water to enter the static mixer II;

the steam stripping unit is a three-kettle steam stripping system, the discharge of the three-kettle steam stripping system is communicated with a second phase splitting tank, and the glue solution enters the post-treatment unit after the two phases of the glue solution pass through the second phase splitting tank;

the post-treatment unit comprises a dehydrator, a dryer and a grinding mill which are connected in sequence, the two discharge ends of the phase separation tank are communicated with the dehydrator, and the dehydrator is communicated with the three-kettle steam stripping system.

Further, the polymerization kettle is a batch type stirring kettle.

Furthermore, the hydrogenation tower comprises a cooling section I, a packing section I, a cooling section II, a packing section II and a cooling section III which are sequentially arranged from the bottom to the top of the tower.

Further, three cauldron steam stripping systems are including the first steam stripping cauldron, second steam stripping cauldron and the third steam stripping cauldron that communicate in proper order, first steam stripping cauldron feeding intercommunication phase separation jar one with the hydroextractor, second steam stripping cauldron with third steam stripping cauldron bottom communicates respectively has the steam source, second steam stripping cauldron with third steam stripping cauldron top is given vent to anger with the steam source communicates after the sprayer mixes to first steam stripping cauldron bottom, first steam stripping cauldron top communicates through the condenser phase separation jar two, two one end of phase separation jar goes out water intercommunication first steam stripping cauldron, and the other end goes out solvent recovery.

Further, the refined butadiene tank is communicated with a butadiene refining unit, the refined styrene tank is communicated with the styrene refining unit, and the refined solvent tank is communicated with a solvent refining unit;

the butadiene refining unit comprises a first rectifying tower, a first alumina drying tower and a first molecular sieve drying tower which are sequentially connected, the bottom end of the first rectifying tower is connected with a first reboiler, the top end of the first rectifying tower is connected with a third condenser, and the first molecular sieve drying tower is connected with the refined butadiene tank in a discharging mode;

the styrene refining unit comprises a second rectifying tower, a second alumina drying tower and a second molecular sieve drying tower which are sequentially connected, the bottom end of the second rectifying tower is connected with a second reboiler, the top end of the second rectifying tower is connected with a fourth condenser, and the second molecular sieve drying tower is connected with the refined styrene tank in a discharging mode;

the solvent alkene refining unit comprises a rectifying tower III, a solvent hydrogenation tower and a molecular sieve drying tower III which are sequentially connected, the bottom end of the rectifying tower III is connected with a reboiler III, the top end of the rectifying tower III is connected with a condenser V, the solvent hydrogenation tower is connected with a hydrogenation catalyst source, and the discharge end of the molecular sieve drying tower III is connected with the refined solvent tank.

The invention also provides a method for preparing medical-grade thermoplastic elastomer by adopting the device in the technical scheme, which comprises the following steps:

the method comprises the following steps: refining of raw materials

Crude butadiene enters a refined butadiene tank after being refined by a butadiene refining unit, crude styrene enters a refined styrene tank after being refined by a styrene refining unit, and a crude solvent enters a refined solvent tank after being refined by a solvent alkene refining unit;

step two: reaction preparation

(2.1) adding refined styrene, a solvent and an auxiliary agent into a polymerization kettle, controlling the temperature of an external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, then adding refined butadiene, controlling the temperature of the external circulation condenser to be less than or equal to 60 ℃, reacting for 30-35min, then adding refined styrene again, controlling the temperature of the external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, finally adding a terminator to finish the reaction, discharging a product, and preparing a block SBS polymer glue solution;

(2.2) preheating the block SBS polymer glue solution to 90 ℃ by a preheater, mixing the block SBS polymer glue solution with a catalyst in a first static mixer, conveying the mixture to a jet mixer for mixing reaction with hydrogen, wherein the addition of the catalyst is 0.01-0.3mmol/100g of the block SBS polymer glue solution and the hydrogen consumption is 30-40 NL/100g of the block SBS polymer glue solution, reacting the mixture in a hydrogenation tower with the pressure of less than or equal to 20bar and the temperature of less than or equal to 140 ℃, sequentially treating the reaction product by a primary flash tank with the pressure of less than or equal to 5bar and the temperature of less than or equal to 120 ℃ and a secondary flash tank with the pressure of less than or equal to 0.1bar and the temperature of less than or equal to 80 ℃, and discharging the bottom of the secondary flash tank to obtain the glue solution;

step three: decatalyst

The glue solution enters a de-catalysis unit, is mixed with acid and pure water through a second static mixer and then enters a neutralization kettle, demulsifier is squeezed into the neutralization kettle, then stirring reaction is completed, the mixture enters a first phase-splitting tank, and the upper glue solution is discharged and enters a stripping unit after phase splitting is performed in the first phase-splitting tank;

step four: stripping

After the glue solution is stripped by adopting a three-kettle stripping system, discharging the glue solution to a post-treatment unit, wherein the volume ratio of circulating hot water to the glue solution is (3-5): 1, stripping by adopting 8barg steam, wherein the volume ratio of the steam to the glue solution is (0.3-0.4): 1;

step five: post-treatment and packaging

And dehydrating the glue solution entering the post-treatment unit by a dehydrator, drying by a dryer, grinding by a grinding mill until the grain diameter is less than or equal to 0.5mm, and packaging to obtain a finished product.

Preferably, in the step one:

in the butadiene refining unit, the pressure of a rectifying tower I is 3bar, the temperature is 30-40 ℃, the water content of butadiene extracted by the rectifying tower I is less than or equal to 15ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the first pressure of an alumina drying tower is 3bar, the temperature is 30-35 ℃, the water content of the extracted butadiene is less than or equal to 5ppm, and TBC is 0; the pressure of the molecular sieve drying tower is 3bar, the temperature is 30-35 ℃, and the water content of the extracted butadiene is less than or equal to 1 ppm;

the pressure of a second rectifying tower in the styrene refining unit is 5KPa, the temperature is 25-65 ℃, the water content of the styrene extracted by the second rectifying tower is less than or equal to 20ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the second pressure of the alumina drying tower is 3bar, the temperature is 25-30 ℃, the water content of the extracted styrene is less than or equal to 5ppm, and TBC is 0; the pressure of the molecular sieve drying tower II is 3bar, the temperature is 25-30 ℃, and the water content of the extracted styrene is less than or equal to 1 ppm;

the third pressure of a rectifying tower in the solvent refining unit is 1-3bar, the temperature is 90-130 ℃, the water content of the solvent extracted by the third rectifying tower is less than or equal to 15ppm, and the cyclopentadiene content is less than or equal to 20 ppm; the pressure of the solvent hydrogenation tower is 5bar, the temperature is 50-60 ℃, and the extracted solvent cyclopentadiene content is less than or equal to 1 ppm; the three pressures of the molecular sieve drying tower are 3bar, the temperature is 30-40 ℃, and the water content of the extracted solvent is less than or equal to 1 ppm;

the hydrogenation catalyst in the solvent hydrogenation tower is nickel or palladium, and the solvent is one of alkane or cycloalkane.

Preferably, the auxiliary agent in the step (2.1) is an initiator, an activating agent and a structure regulator, and the weight ratio of the refined styrene to the refined butadiene to the solvent is (1-3) to (7-9) to 90; the mass ratio of the refined styrene added twice is 1: 1; the dosage of the initiator is 0.05-0.1 g/100g of polymer, the dosage of the activator is 0.04-0.08 g/100g of polymer, and the dosage of the structure regulator is 0.03-0.06 g/100g of polymer;

the initiator is an alkyl lithium initiator, preferably one of n-butyl lithium or sec-butyl lithium;

the activating agent is tetrahydrofuran;

the structure regulator is an amine or alcohol ether regulator, preferably one or two of tetramethylethylenediamine, tetrahydrofurfuryl amine and ethylene glycol dibutyl ether;

the terminator is one of water, alcohols or phenols, and preferably octadecanol.

Preferably, the catalyst in the step (2.2) is one of an aluminum nickel catalyst, a lithium titanium catalyst and an aluminum titanium catalyst, preferably an aluminum titanium catalyst, and is prepared by compounding titanocene dichloride and triisobutyl aluminum, wherein the molar ratio of aluminum to titanium is 8: 1-2: 1, preferably 6: 1-4: 1, and the dosage of the hydrogenation catalyst is 0.01-0.3mmol of Ti per 100g of block SBS polymer, preferably 0.05-0.1 mmol of Ti per 100g of block SBS polymer.

Preferably, the acid in the third step is one or two of citric acid, neodecanoic acid, dilute hydrochloric acid, dilute sulfuric acid and carbonic acid, and the mass ratio of the glue solution, the acid and the pure water is 1: (0.00005-0.0001): 10.

through the technical scheme, compared with the prior art, the invention discloses and provides a device and a method for industrially producing medical-grade thermoplastic elastomers, and the device and the method have the following beneficial effects:

the technical process provided by the invention has excellent continuity, and the SEBS product produced by the process has the advantages of easily controlled 1, 2-butadiene content and molecular weight, narrow molecular weight distribution, high hydrogenation degree, low ash content, transparent and bright blending with PP and no crystal point through process integration and blending and process parameter control, and meets the requirements of medical and sanitary SEBS products.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a polymerization hydrogenation apparatus of a medical grade thermoplastic elastomer industrial production device according to the present invention;

FIG. 2 is a structural diagram of a catalyst removal device of an industrial production device for medical grade thermoplastic elastomers according to the present invention;

FIG. 3 is a structural diagram of a stripping apparatus of an industrial production device for medical grade thermoplastic elastomer according to the present invention;

FIG. 4 is a structural diagram of a post-processing device of an industrial production device for medical grade thermoplastic elastomers according to the present invention;

FIG. 5 is a structural diagram of a styrene refining unit of an industrial production apparatus for medical grade thermoplastic elastomers according to the present invention;

FIG. 6 is a block diagram of a butadiene refining unit of an industrial production apparatus for medical grade thermoplastic elastomers according to the present invention;

FIG. 7 is a structural diagram of a solvent refining unit of an industrial production device for medical grade thermoplastic elastomers according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-7, an industrial production device for medical-grade thermoplastic elastomer comprises: the device comprises a reaction unit, a catalyst removal unit, a steam stripping unit and a post-treatment unit;

the reaction unit comprises a raw material tank 11, a polymerization kettle 12, a preheater 13, a first static mixer 14, a jet mixer 15, a hydrogenation tower 16 and a flash tank 17 which are connected in sequence; the raw material tank 11 comprises a refined butadiene tank 111, a refined styrene tank 112, a refined solvent tank 113 and an auxiliary agent tank 114; the polymerizer 12 is connected with an external circulation condenser 121; the first static mixer 14 is connected with a catalyst tank 141; the jet mixer 15 is connected with a hydrogen tank 151; the flash tank 17 comprises a primary flash tank 171 and a secondary flash tank 172 which are sequentially connected, the hydrogenation tower 16 is communicated with the primary flash tank 171 through a first pressure reducing valve 161, the top end of the primary flash tank 171 is communicated with a first condenser 181, the bottom end of the primary flash tank is communicated with the secondary flash tank 172 through a second pressure reducing valve 173, steam is recovered after the first condenser 181 is treated, the solvent is refined and recycled, the top end of the secondary flash tank 172 is communicated with a second condenser 182, the bottom end of the secondary flash tank is communicated with a de-catalysis unit, non-condensable gas is removed from a torch after the second condenser 182 is treated, and the solvent is refined and recycled;

in the reaction unit, the polymerization kettle 12 is an intermittent stirring kettle, and the hydrogenation tower 16 comprises a first cooling section 162, a first packing section 163, a second cooling section 164, a second packing section 165 and a third cooling section 166 which are sequentially arranged from the bottom to the top;

the refined butadiene tank 111 is communicated with a butadiene refining unit, the refined styrene tank 112 is communicated with a styrene refining unit, and the refined solvent tank 113 is communicated with a solvent refining unit;

the butadiene refining unit comprises a first rectifying tower 51, a first alumina drying tower 52 and a first molecular sieve drying tower 53 which are sequentially connected, wherein the bottom end of the first rectifying tower 51 is connected with a first reboiler 54, the top end of the first rectifying tower 51 is connected with a third condenser 55, the first molecular sieve drying tower 53 is connected with a refined butadiene tank 111 in a discharging manner, heavy fraction residual liquid is discharged from the bottom end of the first rectifying tower 51, and light fraction residual liquid is discharged from the third condenser 55;

the styrene refining unit comprises a second rectifying tower 61, a second alumina drying tower 62 and a second molecular sieve drying tower 63 which are sequentially connected, the bottom end of the second rectifying tower 61 is connected with a second reboiler 64, the top end of the second rectifying tower is connected with a fourth condenser 65, the second molecular sieve drying tower 63 discharges materials and is connected with a refined styrene tank 112, heavy fraction residual liquid is discharged from the bottom end of the second rectifying tower 61, and light fraction residual liquid is discharged from the fourth condenser 65;

the solvent alkene refining unit comprises a rectifying tower III 71, a solvent hydrogenation tower 72 and a molecular sieve drying tower III 73 which are sequentially connected, the bottom end of the rectifying tower III 71 is connected with a reboiler III 74, the top end of the rectifying tower III is connected with a condenser V75, the solvent hydrogenation tower 72 is connected with a hydrogenation catalyst source 76, the discharge of the molecular sieve drying tower III 73 is connected with a refined solvent tank 113, heavy fraction residual liquid is discharged from the bottom end of the rectifying tower III 71, and light fraction residual liquid is discharged from the condenser V75;

the de-catalysis unit comprises a second static mixer 21, a neutralization kettle 22 and a first phase separation tank 23 which are connected in sequence; the bottom end of the secondary flash tank 172 is communicated with a second static mixer 21, and the second static mixer is also communicated with a pure water tank 24 and an acid tank 25; the neutralization kettle 22 is communicated with a demulsifier tank 26; the first phase splitting tank 23 is communicated with the sewage treatment system, the second static mixer 21 and the stripping unit, part of liquid discharged from the first phase splitting tank 23 enters the sewage treatment system for treatment, and part of the liquid is recycled and mixed with glue solution, acid and pure water to enter the second static mixer 21;

the stripping unit is a three-kettle stripping system, the discharge of the three-kettle stripping system is communicated with the second phase splitting tank 31, and the glue solution enters the post-treatment unit after being subjected to phase splitting in the second phase splitting tank 31; the three-kettle stripping system comprises a first stripping kettle 32, a second stripping kettle 33 and a third stripping kettle 34 which are communicated in sequence, the first stripping kettle 32 is fed and communicated with a first phase separation tank 23 and a dehydrator 41, the bottom ends of the second stripping kettle 33 and the third stripping kettle 34 are respectively communicated with a steam source 35, the top air outlet of the second stripping kettle 33 and the top end of the third stripping kettle 34 are mixed with the steam source 35 through an ejector 36 and then communicated to the bottom end of the first stripping kettle 32, the top end of the first stripping kettle 32 is communicated with a second phase separation tank 31 through a condenser 37, one end of the second phase separation tank 31 is provided with water and communicated with the first stripping kettle 32, and the other end of the second phase separation tank is provided with solvent recovery.

The post-treatment unit comprises a dehydrator 41, a dryer 42 and a mill 43 which are connected in sequence, the second phase separation tank 31 is communicated with the dehydrator 41 in a discharging way, and the dehydrator 41 is communicated with the first stripping kettle 32 in a water outlet way.

The method for preparing the medical grade thermoplastic elastomer by using the device comprises the following steps:

the method comprises the following steps: refining of raw materials

Crude butadiene enters a refined butadiene tank 111 after being refined by a butadiene refining unit, crude styrene enters a refined styrene tank 112 after being refined by a styrene refining unit, and a crude solvent enters a refined solvent tank 113 after being refined by a solvent alkene refining unit;

in the butadiene refining unit, the pressure of a rectifying tower I51 is 3bar, the temperature is 30-40 ℃, the water content of butadiene extracted by the rectifying tower I51 is less than or equal to 15ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the pressure of a first 52 bar of an alumina drying tower is 3bar, the temperature is 30-35 ℃, the water content of the extracted butadiene is less than or equal to 5ppm, and TBC is 0; the pressure of a first molecular sieve drying tower 53 is 3bar, the temperature is 30-35 ℃, and the water content of the extracted butadiene is less than or equal to 1 ppm;

in the styrene refining unit, the pressure of a second rectifying tower 61 in the rectifying tower is 5KPa, the temperature is 25-65 ℃, the water content of the styrene extracted by the second rectifying tower 61 is less than or equal to 20ppm, the TBC is less than or equal to 5ppm, and the autopolymer is 0; the pressure of the second 62 alumina drying tower is 3bar, the temperature is 25-30 ℃, the water content of the extracted styrene is less than or equal to 5ppm, and the TBC is 0; the pressure of the second molecular sieve drying tower 63 is 3bar, the temperature is 25-30 ℃, and the water content of the extracted styrene is less than or equal to 1 ppm;

the pressure of a rectifying tower III 71 in the solvent refining unit is 1-3bar, the temperature is 90-130 ℃, the water content of the solvent extracted by the rectifying tower III 71 is less than or equal to 15ppm, and the cyclopentadiene content is less than or equal to 20 ppm; the solvent hydrogenation tower has 72 bar pressure and 50-60 deg.c temperature, and the extracted solvent has cyclopentadiene content not higher than 1 ppm; the pressure of a molecular sieve drying tower III 73 is 3bar, the temperature is 30-40 ℃, and the water content of the extracted solvent is less than or equal to 1 ppm;

the hydrogenation catalyst in the solvent hydrogenation tower 72 is nickel or palladium, the solvent is one of alkane or cycloalkane, in this embodiment, cyclohexane or n-hexane or a mixture of the two is selected.

Step two: reaction preparation

(2.1) adding refined styrene, a solvent and an auxiliary agent into a polymerization kettle, controlling the temperature of an external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, then adding refined butadiene, controlling the temperature of the external circulation condenser to be less than or equal to 60 ℃, reacting for 30-35min, then adding refined styrene again, controlling the temperature of the external circulation condenser to be less than or equal to 50 ℃, reacting for 15-25min, finally adding a terminator to finish the reaction, discharging a product, and preparing a block SBS polymer glue solution;

(2.2) preheating the discharged product to 90 ℃ by a preheater, mixing the preheated product with a catalyst in a first static mixer, conveying the mixture into a jet mixer for mixing reaction with hydrogen, reacting the mixture in a hydrogenation tower with the pressure of less than or equal to 20bar and the temperature of less than or equal to 140 ℃, sequentially treating the mixture by a primary flash tank with the pressure of less than or equal to 5bar and the temperature of less than or equal to 120 ℃ and a secondary flash tank with the pressure of less than or equal to 0.1bar and the temperature of less than or equal to 80 ℃, and discharging the mixture from the bottom of the secondary flash tank to obtain a glue solution;

step three: decatalyst

The glue solution enters a de-catalysis unit, is mixed with acid and pure water through a second static mixer and then enters a neutralization kettle, demulsifier is squeezed into the neutralization kettle, then stirring reaction is completed, the mixture enters a first phase-splitting tank, and the upper glue solution is discharged and enters a stripping unit after phase splitting is performed in the first phase-splitting tank;

the acid is one or two of citric acid, neodecanoic acid, dilute hydrochloric acid, dilute sulfuric acid and carbonic acid, and the mass ratio of the glue solution, the acid and the pure water is 1: (0.00005-0.0001): 10;

step four: stripping

After the glue solution is stripped by adopting a three-kettle stripping system, discharging the glue solution to a post-treatment unit, wherein the ratio of circulating hot water to the glue solution is (3-5): 1, stripping by adopting 8barg steam, wherein the ratio of the steam to the glue solution is (0.3-0.4): 1;

step five: post-treatment and packaging

And dehydrating the glue solution entering the post-treatment unit by a dehydrator, drying by a dryer, grinding by a grinding mill until the grain diameter is less than or equal to 0.5mm, and packaging to obtain a finished product.

Wherein, the auxiliary agents in the step (2.1) are an initiator, an activating agent and a structure regulator, and the weight ratio of the refined styrene to the refined butadiene to the solvent is (1-3) to (7-9) to 90; the mass ratio of the refined styrene added twice is 1: 1; the dosage of the initiator is 0.05-0.1 g/100g of polymer, the dosage of the activator is 0.04-0.08 g/100g of polymer, and the dosage of the structure regulator is 0.03-0.06 g/100g of polymer;

the initiator is an alkyl lithium initiator, and in the embodiment, one of n-butyl lithium or sec-butyl lithium is selected;

the activating agent is tetrahydrofuran;

the structure regulator is amine or alcohol ether regulator, and in this embodiment, one or two of tetramethylethylenediamine, tetrahydrofurfuryl amine, and ethylene glycol dibutyl ether are selected;

the terminator is one of water, alcohols or phenols, and octadecanol is selected in the embodiment.

In the step (2.2), the catalyst is one of an aluminum nickel catalyst, a lithium titanium catalyst and an aluminum titanium catalyst, in this embodiment, the aluminum titanium catalyst is selected and compounded by titanocene dichloride and triisobutyl aluminum, the molar ratio of aluminum to titanium is 8: 1-2: 1, preferably 6: 1-4: 1, and the dosage of the hydrogenation catalyst is 0.01-0.3mmol of Ti per 100g of block SBS polymer, preferably 0.05-0.1 mmol per 100g of block SBS polymer.

The following description will be made by using specific implementation data

Example 1

Firstly putting 900 parts of cyclohexane solvent into a polymerization kettle, then respectively and sequentially adding 15 parts of refined styrene, 70 parts of refined butadiene and 15 parts of refined styrene into the polymerization kettle for block polymerization, controlling the polymerization temperature to be less than or equal to 60 ℃, and preparing a polymer glue solution by using n-butyl lithium (the using amount is 0.07g/100g of polymer), tetrahydrofuran (the using amount is 0.05g/100g of polymer) as an initiator, and tetramethylethylenediamine (the using amount is 0.04g/100g of polymer) as a regulator, wherein the molecular weight of the polymer glue solution is 17-20 ten thousand; an aged aluminum-titanium catalyst (the aluminum-titanium ratio is 5: 1) is adopted for hydrogenation reaction, the addition amount is 0.06mmol Ti/100g polymer, and the product is obtained after discharging and subsequent treatment.

Example 2

Firstly putting 900 parts of cyclohexane solvent into a polymerization kettle, then respectively and sequentially adding 15 parts of refined styrene, 70 parts of refined butadiene and 15 parts of refined styrene into the polymerization kettle for block polymerization, controlling the polymerization temperature to be less than or equal to 60 ℃, and preparing a polymer glue solution by adopting n-butyl lithium (the using amount of which is 0.07g/100g of polymer), tetrahydrofuran (the using amount of which is 0.05g/100g of polymer) as an initiator, and ethylene glycol dibutyl ether (the using amount of which is 0.05g/100g of polymer) as a regulator, wherein the molecular weight of the polymer glue solution is 17-20 ten thousand; an aged aluminum-titanium catalyst (aluminum-titanium ratio is 4: 1) is adopted for hydrogenation reaction, the addition amount is 0.06mmol Ti/100g polymer, and the product is obtained after discharging and subsequent treatment.

Example 3

Firstly putting 900 parts of cyclohexane solvent into a polymerization kettle, then respectively and sequentially adding 6 parts of refined styrene, 88 parts of refined butadiene and 6 parts of refined styrene into the polymerization kettle for block polymerization, controlling the polymerization temperature to be less than or equal to 60 ℃, and preparing a polymer glue solution by using n-butyl lithium (the using amount of which is 0.07g/100g of polymer), tetrahydrofuran (the using amount of which is 0.05g/100g of polymer) as an initiator, and tetramethylethylenediamine (the using amount of which is 0.06g/100g of polymer) as a regulator, wherein the molecular weight of the polymer glue solution is 17-20 ten thousand; an aged aluminum-titanium catalyst (the aluminum-titanium ratio is 5: 1) is adopted for hydrogenation reaction, the addition amount is 0.08mmol Ti/100g polymer, and the product is obtained after discharging and subsequent treatment.

Example 4

Firstly putting 900 parts of cyclohexane solvent into a polymerization kettle, then respectively and sequentially adding 6 parts of refined styrene, 88 parts of refined butadiene and 6 parts of refined styrene into the polymerization kettle for block polymerization, controlling the polymerization temperature to be less than or equal to 60 ℃, and preparing a polymer glue solution by adopting n-butyl lithium (the using amount is 0.07g/100g of polymer), tetrahydrofuran (the using amount is 0.05g/100g of polymer) as an initiator, and tetrahydrofurfuryl amine (the using amount is 0.05g/100g of polymer) as a regulator, wherein the molecular weight of the polymer glue solution is 17-20 ten thousand; an aged aluminum-titanium catalyst (the aluminum-titanium ratio is 6: 1) is adopted for hydrogenation reaction, the addition amount is 0.08mmol Ti/100g polymer, and the product is obtained after discharging and subsequent treatment.

The SEBS product obtained in the above example was tested and the results were as follows:

the SEBS product produced by the process has the advantages of easily controlled 1,2 butadiene content and molecular weight, narrow molecular weight distribution, high hydrogenation degree, low ash content, transparent blending with PP, no crystal point and capability of meeting the requirements of medical and sanitary SEBS products.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.