Block copolymer manufacturing method

Abstract

The present invention relates to a method and apparatus for manufacturing a block copolymer, and more specifically, provides a method for manufacturing a block copolymer comprising the steps of: introducing an aromatic vinyl monomer into a first reactor to polymerize an aromatic vinyl monomer block (S10); supplying a discharge stream from the first reactor containing the aromatic vinyl monomer block to a second reactor and introducing a conjugated diene monomer into the second reactor first to polymerize a first diblock copolymer containing the aromatic vinyl monomer block and the first conjugated diene monomer block (S20); and, at the point when the polymerization conversion rate of step (S20) is 90% or more, introducing a conjugated diene monomer into the second reactor secondly and polymerizing while removing the reaction heat to polymerize a second diblock copolymer containing the aromatic vinyl monomer block and the second conjugated diene monomer block (S30).

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a block copolymer, and more specifically, to a method for manufacturing a block copolymer using an aromatic vinyl monomer and a conjugated diene monomer. Background Technology

[0002] Generally, a styrene-butadiene-styrene triblock copolymer (poly(styrene-butadiene-styrene), SBS) is produced by introducing a styrene monomer and a solvent into a batch reactor to polymerize a styrene monomer block, then introducing a butadiene monomer to produce a styrene-butadiene diblock copolymer, and then introducing a coupling agent such as silicon tetrachloride (SiCl4) to perform a coupling reaction.

[0003] At this time, the polymerization reaction in the batch reactor is an adiabatic reaction, and the temperature of the input monomer and solvent increases; once the final polymerization temperature at which physical properties are secured is determined, the input ratio of the monomer and solvent is determined.

[0004] Therefore, to improve productivity, the monomer-to-solvent input ratio must be increased; however, there is a limit to increasing this ratio because raising the ratio raises the polymerization temperature due to reaction heat, which can degrade the physical properties of the block copolymer. Furthermore, if the monomer-to-solvent ratio is lowered to prevent the degradation of block copolymer properties, the block copolymer content in the final polymer decreases, leading to reduced productivity. Consequently, there was a disadvantage in that the energy consumed during the desolvation process to obtain the final product increased.

[0005] In addition, the manufacturing process of SBS, which proceeds as a batch reaction and involves introducing butadiene monomers to perform polymerization after polymerizing styrene monomer blocks in the same reactor, had a problem in that unreacted butadiene monomers remained in the reactor as vapor when the reaction was finished and the polymer was discharged, and when styrene monomers and solvents were introduced to proceed with polymerization in a subsequent batch reaction in the same reactor, the butadiene monomers remaining in the reactor dissolved in the solvent to form random polystyrene. Prior art literature

[0006] JP 1994-025236 B2 The problem to be solved

[0007] The objective of the present invention is to provide a method for manufacturing a block copolymer that solves the problem of random copolymer formation by batch reaction, by preventing the polymerization temperature inside the reactor from rising even if the reaction heat increases due to an increase in the ratio of monomer to solvent introduced during polymerization, thereby preventing the physical properties of the block copolymer from deteriorating, in order to solve the problems mentioned in the background technology of the invention. means of solving the problem

[0008] According to one embodiment of the present invention for solving the above problem, the present invention provides a method for manufacturing a block copolymer comprising: a step (S10) of polymerizing an aromatic vinyl monomer block by introducing an aromatic vinyl monomer into a first reactor; a step (S20) of supplying a discharge stream of the first reactor containing the aromatic vinyl monomer block to a second reactor and introducing a conjugated diene monomer into the second reactor first to polymerize a first diblock copolymer containing the aromatic vinyl monomer block and the first conjugated diene monomer block; and a step (S30) of introducing a conjugated diene monomer into the second reactor secondly at a time when the polymerization conversion rate of step (S20) is 90% or more, and polymerizing while removing the reaction heat to polymerize a second diblock copolymer containing the aromatic vinyl monomer block and the second conjugated diene monomer block. Effects of the invention

[0009] Through the method for manufacturing a block copolymer according to the present invention, even if the reaction heat increases due to an increase in the ratio of monomer to solvent introduced during polymerization, the polymerization temperature inside the reactor is prevented from rising, thereby preventing the deterioration of the physical properties of the block copolymer and solving the problem of random copolymers being formed by batch reaction.

[0010] That is, by using reactors independently for the polymerization of aromatic vinyl monomers and conjugated diene monomers, the gaseous conjugated diene monomer remaining in the reactor does not participate in the polymerization of aromatic vinyl monomers, thereby preventing the formation of random copolymers.

[0011] In addition, by dividing the conjugated diene monomer into primary and secondary inputs and performing heat removal of the reaction heat only when the secondary conjugated diene monomer is input, the polymerization temperature inside the reactor is prevented from rising even if the reaction heat increases due to an increase in the ratio of monomer input to solvent, thereby preventing the physical properties of the block copolymer from deteriorating, and consequently, the productivity of the block copolymer is improved, and consequently, the energy consumed in the desolvation process for obtaining the final product is reduced. Brief explanation of the drawing

[0012] FIG. 1 is a process flow diagram showing a method for manufacturing a block copolymer according to one embodiment of the present invention. Figure 2 is a process flow diagram showing a conventional method for manufacturing block copolymers. Specific details for implementing the invention

[0013] Terms and words used in the description and claims of the present invention shall not be interpreted as being limited to their ordinary or dictionary meanings, but shall be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0015] In the present invention, the term 'upper' refers to a portion corresponding to a height of 50% or more of the total height of the device within the container, and 'lower' may refer to a portion corresponding to a height of less than 50% of the total height of the container or device.

[0016] In the present invention, the term 'block' may refer to a group of repeating units composed solely of repeating units derived from the same monomer, in which only the same monomer participates in the polymerization reaction within the copolymer.

[0017] In the present invention, the term 'block copolymer' may include repeating units derived from two or more monomers. For example, 'block copolymer' may mean a di-block copolymer, a tri-block copolymer, or a multiblock copolymer.

[0018] In the present invention, the terms 'derived repeating unit' and 'derived linker' may refer to a component, structure, or the substance itself derived from a certain substance. Specifically, 'derived repeating unit' may refer to a repeating unit formed within a polymer by a monomer introduced during polymerization and participating in the polymerization reaction, and 'derived linker' may refer to a linker that connects each polymer within a coupled polymer by a coupling agent introduced during a coupling reaction between polymers and participating in the coupling reaction.

[0019] In the present invention, the term 'stream' may refer to the flow of fluid within a process, and may also refer to the fluid itself flowing within the piping. Specifically, the 'stream' may simultaneously refer to the fluid itself flowing within the piping connecting each device and the flow of the fluid. Additionally, the fluid may refer to a gas or a liquid.

[0021] Hereinafter, to facilitate understanding of the present invention, the present invention will be explained in more detail with reference to FIGS. 1 and 2 below.

[0022] According to the present invention, a method for manufacturing a block copolymer is provided. The method for manufacturing a block copolymer may include the steps of: introducing an aromatic vinyl monomer into a first reactor to polymerize an aromatic vinyl monomer block (S10); supplying a discharge stream from the first reactor containing the aromatic vinyl monomer block to a second reactor and introducing a conjugated diene monomer into the second reactor first to polymerize a first diblock copolymer containing the aromatic vinyl monomer block and the first conjugated diene monomer block (S20); and, at the point when the polymerization conversion rate of step (S20) is 90% or higher, introducing a conjugated diene monomer into the second reactor second to polymerize while removing the reaction heat to polymerize a second diblock copolymer containing the aromatic vinyl monomer block and the second conjugated diene monomer block (S30).

[0024] Generally, a diblock copolymer using aromatic vinyl monomers and conjugated diene monomers can be prepared by introducing an aromatic vinyl monomer and a solvent into a batch reactor to polymerize an aromatic vinyl monomer block, and then introducing a conjugated diene monomer and polymerizing it to produce a diblock copolymer containing the aromatic vinyl monomer block and the conjugated diene monomer block. Additionally, a triblock copolymer using the vinyl monomer and conjugated diene monomer can be prepared by introducing a coupling agent, such as silicon tetrachloride (SiCl4), into a polymer solution containing the prepared diblock copolymer and inducing a coupling reaction.

[0025] At this time, since the polymerization reaction in the batch reactor is an adiabatic reaction, and increasing the ratio of monomer to solvent input to improve productivity may cause the polymerization temperature to rise due to the heat of reaction, thereby degrading the physical properties of the resulting polymer (hereinafter referred to as diblock copolymer or triblock copolymer), it is desirable to maintain the polymerization temperature below a certain temperature.

[0026] In addition, the physical properties of the polymer can be controlled by controlling the polymerization temperature. For example, when polymerization is performed at a temperature of 120°C or lower, a diblock copolymer with a linear structure and relatively constant chain length can be produced, and thus, when the diblock copolymer is coupled using a coupling agent to produce the triblock copolymer, the coupling efficiency can be improved. On the other hand, when polymerization is performed at a temperature of 120°C or higher, a diblock copolymer with non-constant chain length and a reduced proportion of linear polymer is produced, and when the diblock copolymer is coupled using a coupling agent to produce the triblock copolymer, the coupling efficiency is lowered, and a triblock copolymer with degraded physical properties may be produced.

[0027] Accordingly, in the present invention, by controlling the polymerization temperature in the reactor, that is, the operating temperature of the reactor, to 80 to 150 ℃, 100 to 130 ℃, or 100 to 120 ℃, the diblock copolymer having a linear structure with a relatively constant chain length can be produced, thereby enabling the production of a triblock copolymer with excellent coupling efficiency.

[0028] Furthermore, in the manufacturing process of diblock copolymers or triblock copolymers, which proceeds as a batch reaction in which the polymerization of conjugated diene monomers is performed after the polymerization of aromatic vinyl monomer blocks in the same reactor, there was a problem in that unreacted conjugated diene monomers remained in the reactor as vapor when the reaction ended and the final polymer was discharged. Consequently, when aromatic vinyl monomers and a solvent were introduced to proceed with polymerization during a subsequent batch reaction in the same reactor, the gaseous conjugated diene monomers remaining in the reactor dissolved in the solvent, forming a random copolymer.

[0029] Accordingly, in the present invention, by using reactors in which the polymerization of aromatic vinyl monomers and the polymerization of conjugated diene monomers are performed independently, the gaseous conjugated diene monomer remaining in the reactor does not participate in the polymerization of aromatic vinyl monomers, thereby preventing the formation of random copolymers.

[0030] In addition, by dividing the conjugated diene monomer into primary and secondary inputs and performing heat removal of the reaction heat when the secondary conjugated diene monomer is input, the polymerization temperature inside the reactor is prevented from rising even if the reaction heat increases due to an increase in the ratio of monomer input to solvent, thereby allowing for the acquisition of a polymer with desired properties (diblock copolymer or triblock copolymer) and improving the productivity of the block copolymer, and consequently, reducing the energy consumed in the desolvation process for obtaining the final product.

[0031] In the present invention, the term 'random copolymer' may refer to a copolymer in which aromatic vinyl monomers and conjugated diene monomers are irregularly distributed throughout the entire chain forming the copolymer due to conjugated diene monomers remaining in the reactor during the polymerization of an aromatic vinyl monomer block by a polymerization reaction of an aromatic vinyl monomer in the reactor. For example, if the aromatic vinyl monomer is styrene and the conjugated diene monomer is butadiene, the 'random copolymer' may be referred to as 'random polystyrene' and may refer to a styrene-butadiene copolymer (SB) in which styrene monomers and butadiene monomers are irregularly distributed.

[0033] According to one embodiment of the present invention, a method for manufacturing a block copolymer according to the present invention may include a step (S10) of introducing an aromatic vinyl monomer into a first reactor (100) to polymerize an aromatic vinyl monomer block.

[0034] As a specific example, the aromatic vinyl monomer may be introduced into the first reactor (100) in a single batch. Additionally, polymerization within the first reactor (100) may be performed in an adiabatic state. In this way, when the aromatic vinyl monomer is introduced into the first reactor (100) in a single batch and polymerization is performed in an adiabatic state, the polymerization time of the vinyl monomer polymerized within the first reactor (100) can be minimized, and a polymer with a constant molecular weight can be obtained.

[0035] At this time, the polymerization in step (S10) above may be terminated when the polymerization conversion rate is 99.5% or higher, 99.5 to 100%, or 99.8 to 100%.

[0036] Meanwhile, according to one embodiment of the present invention, the polymerization conversion rate in step (S10) may be calculated by taking a certain amount of sample from the reactants being reacted at regular time intervals, calculating the TSC (Total Solid Content) of the sample, and then substituting it into the following mathematical formula 1.

[0037] [Mathematical Formula 1]

[0038] Polymerization conversion rate (%) = {(TSC × W t,t - W t,s ) / W t,m} ⅹ 100

[0039] * TSC: Weight of dried sample solids / Weight of sample before drying

[0040] * W t,t : The sum of the weights of monomers, water, and auxiliary materials added during polymerization

[0041] * W t,s : Total weight of auxiliary materials added other than monomers and water

[0042] * W t,m : Total weight of monomers added during polymerization

[0043] * Auxiliary materials: Additives such as emulsifiers, initiators, and molecular weight regulators, excluding the monomers and water added during polymerization.

[0045] According to one embodiment of the present invention, in step (S10), the polymerization termination point can be determined by measuring the TSC or by the polymerization temperature. For example, when the reaction of an aromatic vinyl monomer is performed under adiabatic conditions, the temperature inside the reactor at the polymerization termination point of the aromatic vinyl monomer can be predicted based on the input amount of the aromatic vinyl monomer and the input amount of the solvent.

[0046] As a more specific example, by referring to literature reported on the relationship between the input amount of aromatic vinyl monomer and the heat of polymerization, if styrene is used as the aromatic vinyl monomer in step (S10) above, and the polymerization reaction is performed using a mixed solvent of hexane and cyclohexane in which the styrene content among the total input monomers is 30 to 32% and the cyclohexane content is 85 to 90%, it can be seen that if the TSC is 22 to 24%, the temperature at which the conversion rate of the styrene reaches 100% is 18 to 20 ℃ higher than the initial input temperature, and the polymerization conversion rate of styrene according to temperature can be predicted.

[0048] According to one embodiment of the present invention, the aromatic vinyl monomer may include one or more selected from the group consisting of styrene, alpha-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, isopropenylnaphthalene, 1-vinylnaphthalene, styrene substituted with an alkyl group having 1 to 3 carbon atoms, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, and styrene substituted with a halogen, but is not limited thereto. As a specific example, the aromatic vinyl monomer may be styrene, in which case the block copolymer polymerized from the second reactor (200) described later has an excellent productivity effect.

[0049] According to one embodiment of the present invention, the conjugated diene monomer may include one or more selected from the group consisting of 1,3-butadiene, 1,4-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene, piperylene, 3-butyl-1,3-octadiene, 2-phenyl-1,3-butadiene, and isoprene, but is not limited thereto. As a specific example, the conjugated diene monomer may be 1,3-butadiene or 1,4-butadiene, and accordingly, the block copolymer produced by the polymerization reaction may be a block copolymer comprising a styrene polymer block and a butadiene polymer block. In this case, the block copolymer polymerized from the second reactor (200) described later has the effect of excellent productivity.

[0051] According to one embodiment of the present invention, a method for manufacturing a block copolymer according to the present invention may perform a step (S20) after step (S10), wherein the discharge stream of a first reactor (100) containing the aromatic vinyl monomer block is supplied to a second reactor (200), and a conjugated diene monomer is first introduced into the second reactor (200) to polymerize a first diblock copolymer containing the aromatic vinyl monomer block and the first conjugated diene monomer block.

[0052] As described above, in the present invention, by using a first reactor (100) in which the polymerization of an aromatic vinyl monomer is performed and a second reactor (200) in which the polymerization of a conjugated diene monomer is performed independently, the gaseous conjugated diene monomer remaining in the second reactor (200) after the polymerization reaction does not participate in the polymerization of the aromatic vinyl monomer performed in the first reactor (100), thereby preventing the formation of the random copolymer.

[0053] According to one embodiment of the present invention, the conjugated diene monomer introduced first may be introduced collectively into the second reactor (200). Additionally, the polymerization of the conjugated diene monomer introduced first into the second reactor (100) may be performed in an adiabatic state.

[0054] In this way, when the conjugated diene monomers introduced first into the second reactor (200) are introduced in bulk and polymerization is performed in an adiabatic state, the polymerization time of the conjugated diene monomers introduced first can be minimized and a polymer with a constant molecular weight can be obtained, and the productivity of the second diblock copolymer produced from the second reactor (200) in the subsequent step (S30) is excellent.

[0056] According to one embodiment of the present invention, a method for manufacturing a block copolymer according to the present invention may perform a step (S30) of polymerizing a second diblock copolymer comprising the aromatic vinyl monomer block and the second conjugated diene monomer block by introducing a second conjugated diene monomer into the second reactor (200) at a time when the polymerization conversion rate of the step (S20) is 90% or more after the step (S20).

[0057] In the present invention, the term 'heat removal' may refer to a process of removing part or all of the reaction heat generated as the polymerization reaction proceeds within the reactor, thereby controlling the temperature inside the reactor that rises due to the reaction heat.

[0058] As a specific example, the removal of reaction heat in step (S30) above can be performed by condensing a discharge stream containing a gaseous conjugated diene monomer vaporized by reaction heat from the second reactor (200) using a heat removal device (300) and then recirculating it to the second reactor (200). That is, by removing the reaction heat within the second reactor (200), the temperature inside the second reactor (200), which is raised by the reaction heat, can be controlled.

[0059] According to one embodiment of the present invention, the discharge stream containing the gaseous conjugated diene monomer is condensed to 30 to 45 ℃ or 35 to 40 ℃ by the heat removal device (300) and then refluxed to the second reactor (200), thereby maintaining the polymerization temperature in the second reactor (200) at 100 to 120 ℃ or 110 to 200 ℃. In this case, the physical properties of the block copolymer can be prevented from deteriorating due to the rise in the polymerization temperature, and there is also an effect of increasing the content of the block copolymer in the polymer solution.

[0060] For example, the heat removal device (300) may be a heat exchanger, i.e., a condenser. In this way, unlike the first reactor (100) where polymerization is performed in an adiabatic state, the upper part of the second reactor (200) may be equipped with a heat removal device (300) for removing reaction heat.

[0061] According to one embodiment of the present invention, a valve (not shown) connected to the second reactor (200) and the heat removal device (300) may be further provided at the top of the second reactor (200), and the flow rate of the discharge stream containing the conjugated diene monomer that is vaporized by the reaction heat in the second reactor (100) may be controlled by adjusting the degree of opening and closing of the valve (not shown).

[0062] For example, referring to FIG. 1, in order to maintain an adiabatic state during the polymerization of step (S20), the valve (not shown) is kept in a closed state, thereby preventing the discharge stream containing the gaseous conjugated diene monomer that is vaporized by the reaction heat in the second reactor (200) from being discharged to the top of the second reactor (200). Meanwhile, as described above, in order to remove the reaction heat generated in the polymerization of step (S30), the valve (not shown) is kept in an open state so that a discharge stream containing gaseous conjugated diene monomers that are vaporized by the reaction heat in the second reactor (200) can be discharged to the top of the second reactor (200), and accordingly, the discharge stream containing gaseous conjugated diene monomers can be returned to the second reactor (200) after passing through the heat removal device (300).

[0063] Meanwhile, according to one embodiment of the present invention, the point in time when the polymerization conversion rate of step (S20) is 90% or higher may mean the point in time when the polymerization conversion rate is 90% or higher based on the conjugated diene monomer first introduced in step (S20).

[0064] In addition, the polymerization conversion rate in step (S20) above may be calculated by taking a certain amount of sample from the reactants being reacted at regular time intervals, calculating the TSC (Total Solid Content) of the sample, and then substituting it into the following mathematical formula 2.

[0065] [Mathematical Formula 2]

[0066] Polymerization conversion rate (%) = {(TSC × W t,t - W t,s ) / W t,m} ⅹ 100

[0067] * TSC: Weight of dried sample solids / Weight of sample before drying

[0068] * W t,t: The sum of the weights of the aromatic vinyl monomer blocks added during polymerization, the primary added conjugated diene monomers, water, and auxiliary materials.

[0069] * W t,s : The sum of the weights of auxiliary materials added, excluding the aromatic vinyl monomer block, the primary added conjugated diene monomer, and water.

[0070] * W t,m : Weight sum of aromatic vinyl monomer blocks added during polymerization and primary added conjugated diene monomers

[0071] * Auxiliary materials: Additives such as emulsifiers, initiators, and molecular weight regulators, excluding aromatic vinyl monomer blocks added during polymerization, primary added conjugated diene monomers, and water.

[0073] According to one embodiment of the present invention, in step (S30), the conjugated diene monomer that is secondarily introduced may be continuously introduced into the second reactor (200).

[0074] As described above, unlike the first input conjugated diene monomer being input into the second reactor (200) in the above step (S20), the second input conjugated diene monomer can be continuously input into the second reactor (200) at a uniform input rate.

[0075] At this time, since the heat of polymerization by the conjugated diene monomer introduced secondarily must be removed by a heat removal device (300) provided at the top of the second reactor (200), the amount of heat removed by the heat removal device (300) provided at the top of the second reactor (200) can be determined according to the rate of introduction of the conjugated diene monomer introduced secondarily relative to the volume of the second reactor (200).

[0076] For example, if the input rate of the conjugated diene monomer being secondarily input relative to the volume of the second reactor (200) is high, the amount of the discharge stream containing the gaseous conjugated diene monomer that is vaporized in the second reactor (200) increases in order to maintain the polymerization temperature, which increases the load on the heat removal device (300) and thus increases facility costs. Additionally, as the second diblock copolymer is entrained together with the gaseous conjugated diene monomer that is vaporized in the second reactor (200) in the discharge stream, fouling may occur in the heat removal device (300) located at the top of the second reactor (200). Meanwhile, if the input rate of the conjugated diene monomer being secondarily input relative to the volume of the second reactor (200) is low, the polymerization time increases, and the production yield per unit time decreases.

[0077] As a specific example, the input rate of the conjugated diene monomer introduced secondarily relative to the volume of the second reactor (200) may be 3.0 g / (min*L) or less, or 2.4 to 3.0 g / (min*L). When the input rate of the conjugated diene monomer introduced secondarily is 2.4 g / (min*L) or more, as described above, the polymerization time may be reduced so that the production yield per unit time may increase, and also, there is an effect of increasing the content of the second diblock copolymer in the final polymer. Meanwhile, if the input rate of the second conjugated diene monomer is 3.0 g / (min*L) or less, the second diblock copolymer is prevented from being discharged together with the gaseous conjugated diene monomer in the discharge stream from the top of the second reactor (200), thereby preventing fouling caused by the second diblock copolymer passing through the heat removal device (300), and thus, the long-term operation of the process is facilitated.

[0079] According to one embodiment of the present invention, in step (S20), the amount of conjugated diene monomer introduced first can be controlled so that the peak temperature in the reactor is 120°C or lower. For example, if the initial temperature at the time of the first introduction of the conjugated diene monomer is 60 to 80°C, the point at which the polymerization conversion rate is 90% or higher may be 110 to 117°C. As a specific example, if the conjugated diene monomer is 1,3-butadiene and the initial temperature at the time of the first introduction is 60 to 65°C, and the polymerization reaction proceeds with a TSC of 20 to 25% in the reactor, the point at which the polymerization conversion rate is 99% or higher may be 115 to 116°C. Accordingly, the point at which the polymerization conversion rate is 90% may be 110 to 111°C.

[0080] In the above step (S20), the amount of the first-introduced conjugated diene monomer can be adjusted so that even if the polymerization conversion rate of the first-introduced conjugated diene monomer reaches 100%, the polymerization temperature inside the reactor is maintained at 110 to 120 ℃ by the polymerization heat of the first-introduced conjugated diene monomer. The polymerization temperature inside the reactor can be controlled by adjusting the amount of the first-introduced conjugated diene monomer in the same manner as the method of predicting the polymerization temperature inside the reactor based on the amount of the aromatic vinyl monomer described above.

[0081] If the amount of the first-stage conjugated diene monomer is increased, the polymerization temperature inside the reactor exceeds 120°C due to the first-stage conjugated diene monomer, resulting in the production of a diblock copolymer with non-uniform chain lengths and a reduced proportion of linear polymer structures. Consequently, when the diblock copolymer is coupled using a coupling agent to produce a triblock copolymer, the coupling efficiency decreases, which may result in the production of a triblock copolymer with degraded physical properties. On the other hand, if the amount of the first-stage conjugated diene monomer is decreased, the amount of the second-stage conjugated diene monomer increases, which increases the overall polymerization time and may lead to a decrease in productivity.

[0083] According to one embodiment of the present invention, relative to the total amount of the first and second input conjugated diene monomers, the amount of the first input conjugated diene monomer may be 30 to 70 weight%, 40 to 70 weight%, 50 to 70 weight%, or 60 to 70 weight%, and the amount of the second input conjugated diene monomer may be 30 to 70 weight%, 30 to 60 weight%, 30 to 50 weight%, or 30 to 40 weight%.

[0084] When the amount of the first conjugated diene monomer introduced is 30% by weight or more and the amount of the second conjugated diene monomer introduced is 70% by weight or less, the content of the block copolymer solid in the polymer solution produced in the second reactor (200) is prevented from rising excessively, thereby facilitating the discharge of the polymer solution from the second reactor (200). Meanwhile, if the amount of the first-stage input conjugated diene monomer is 70% by weight or less and the amount of the second-stage input conjugated diene monomer is 30% by weight or more, it is possible to produce a polymer solution containing the maximum amount of block copolymer solids while allowing easy discharge from the second reactor (200), and also prevent the formation of random copolymers, thereby having the effect of improving the productivity of the block copolymer.

[0086] According to one embodiment of the present invention, the method may further include a step (S40) of introducing a coupling agent into the second reactor to obtain a triblock copolymer after the polymerization of step (S30) is completed. In this way, when a coupling agent is introduced after step (S30), a coupling reaction of the second diblock copolymer produced by the polymerization of step (S23) is performed, and a triblock copolymer comprising a coupling agent-derived linker can be formed.

[0087] As a specific example, the above step (S40) may be performed 1 to 20 minutes, 3 to 15 minutes, or 5 to 10 minutes after the polymerization of the above step (S30) is completed. Additionally, the coupling reaction may be terminated after 5 to 40 minutes, 5 to 30 minutes, or 5 to 15 minutes have elapsed since the addition of the coupling agent.

[0088] After the above coupling reaction is completed, the polymer solution containing the coupled polymer, the triblock copolymer, is discharged from the second reactor (200), and the solvent and unreacted monomers are removed to finally obtain the triblock copolymer.

[0089] The above coupling agent may include one or more selected from the group consisting of silicon tetrachloride (SiCl4), tetramethoxysilane (Si(OCH3)4), dimethyldichlorosilane (Si(CH3)2Cl2) and tin chloride (IV) (SnCl4), but is not limited thereto. As a specific example, the above coupling agent may be silicon tetrachloride (SiCl4), and in this case, the coupling reaction efficiency of the second diblock copolymer polymerized from the second reactor (200) is excellent, so the productivity of the triblock copolymer is excellent.

[0090] According to one embodiment of the present invention, the aromatic vinyl monomer is styrene, the conjugated diene monomer is butadiene, and the triblock copolymer may be a styrene-butadiene-styrene triblock copolymer (SBS).

[0091] In the method for manufacturing a block copolymer according to the present invention, when the aromatic vinyl monomer is styrene and the conjugated diene monomer is butadiene, the formation of random polystyrene in the polymer solution produced can be prevented and the content of the SBS triblock copolymer can be increased, so that the productivity is excellent and the energy consumed during desolvation to obtain the final SBS product is reduced.

[0092] According to one embodiment of the present invention, as described above, when manufacturing an SBS triblock copolymer, a reactor in which the polymerization of an aromatic vinyl monomer and the polymerization of a conjugated diene monomer are performed is independently used as a first reactor (100) and a second reactor (200), respectively; and when the conjugated diene monomer introduced into the second reactor (200) is divided and introduced in the first and second stages according to the aforementioned division ratio, wherein the conjugated diene monomer allocated during the first introduction is introduced in a lump sum, and the conjugated diene monomer allocated during the second introduction is introduced evenly and continuously at an appropriate introduction rate relative to the volume of the second reactor (200), and polymerization is performed while removing the reaction heat (an adiabatic reaction during the first introduction of butadiene), no random polystyrene is generated in the final SBS triblock copolymer, and the solid content (TSC) of the SBS triblock copolymer in the polymer solution is high, resulting in excellent productivity and the ability to reduce energy consumed during desolvation. You can verify it.

[0093] Meanwhile, for example, when manufacturing an SBS triblock copolymer, even if the first reactor (100) and the second reactor (200) are used independently, if the conjugated diene monomer introduced into the second reactor (200) is not divided into first and second inputs, or if the division ratio deviates from the division ratio mentioned above, or if the input speed relative to the volume of the second reactor (200) deviates from the input speed range mentioned above, or if the reaction heat is not removed during the second input of the conjugated diene monomer, the solid content (TSC) of the SBS triblock copolymer in the polymer solution is low, which not only reduces productivity, but also causes the second diblock copolymer to be discharged together with the gaseous conjugated diene monomer from the top of the second reactor (200), and the polymer or the second diblock copolymer may pass through the heat removal device (300), thereby causing a fouling phenomenon.

[0095] Although the method for manufacturing a block copolymer according to the present invention has been described and illustrated in the drawings above, the description and drawings above describe and illustrate only the essential components for understanding the present invention. In addition to the processes and apparatus described and drawings above, processes and apparatus not separately described and illustrated may be appropriately applied and utilized to carry out the method for manufacturing a block copolymer according to the present invention.

[0097] The present invention will be described in more detail below through examples. However, the following examples are intended to illustrate the present invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, and the scope of the present invention is not limited only to these examples.

[0099] < Examples >

[0100] Examples 1

[0101] As shown in the process flow diagram in Fig. 1, a mixed solution of solvent and styrene monomer (SM) and n-butyl lithium were introduced into a first reactor (100) with a capacity of 50 L, and polymerization was started at 40°C or higher. After the polymerization was terminated when the polymerization conversion rate was 99.8% or higher, the discharge stream of the first reactor (100) containing the styrene monomer block from which polymerization was completed was supplied to a second reactor (200) with a capacity of 50 L.

[0102] At this time, a separate heat removal means was not provided at the top of the first reactor (100), and a condenser, which is a heat removal device (300), was provided at the top of the second reactor (200). In addition, a mixed solvent of n-hexane and cyclohexane with a cyclohexane content of 87 weight% was used as the solvent.

[0103] Subsequently, when the internal temperature of the second reactor (200) was 63 ℃, a butadiene monomer (BD) was first introduced to start polymerization, and a first diblock copolymer comprising the styrene monomer block and the first butadiene monomer block was polymerized. At this time, the amount of the butadiene monomer introduced first was 70 weight% relative to the total amount of butadiene monomer introduced into the second reactor (200).

[0104] Subsequently, after reaching the peak temperature of 115.9 ℃ during the polymerization of the first butadiene monomer, 1 minute later, the remaining amount of 30 wt% of butadiene monomer was evenly added as a second addition (continuous addition) over 10 minutes to polymerize the second diblock copolymer containing the styrene monomer block and the second butadiene monomer block. At this time, the upper discharge stream containing butadiene in vapor, which is vaporized from the second reactor (200) and discharged upwards, was passed through the condenser (300) to condense it to 30 to 45 ℃ so that the internal temperature of the second reactor (200) was maintained at 110 ℃, and then polymerization was performed while refluxing it to the second reactor (200).

[0105] Subsequently, 5 minutes after the polymerization of the second diblock copolymer was completed, silicon tetrachloride (SiCl4), a coupling agent, was added, and the coupling reaction was terminated after 10 minutes, and by removing the solvent in the polymer solution and the remaining unreacted monomer, a polymer containing styrene-butadiene-styrene triblock copolymer (SBS) was obtained.

[0106] After discharging the polymer from the above reactor, a second polymerization was performed in the same reactor in the manner described above, as shown in the process flow of Fig. 1, to obtain the polymer for the second polymerization.

[0107] The total solid content (TSC) of the SBS copolymer in the polymer for the second polymerization was 22.2 wt%, the content of butadiene blocks in the SBS copolymer was 69.1 wt%, and the content of random polystyrene (random PS) was 0 wt%.

[0108] In the above process, the splitting ratio when the butadiene monomer is secondarily added, the input rate relative to the volume of the second reactor (200) when the butadiene monomer is secondarily added, and the solid content of SBS in the polymer are shown in Table 1 below.

[0110] Examples 2

[0111] In the above Example 1, the process was simulated in the same manner as in Example 1, except that the splitting ratio of the butadiene monomer during the second input was 50 wt% (50 wt% during the first input) and the input rate relative to the volume of the second reactor (200) during the second input was 2.67 g / (min*L).

[0113] Examples 3

[0114] In the above Example 1, the process was simulated in the same manner as in Example 1, except that the splitting ratio of the butadiene monomer during the second input was 62 wt% (38 wt% during the first input) and the input rate relative to the volume of the second reactor (200) during the second input was 2.82 g / (min*L).

[0116] Examples 4

[0117] In the above Example 1, the process was simulated in the same manner as in Example 1, except that the splitting ratio of the butadiene monomer during the second input was 68 wt% (32 wt% during the first input) and the input rate relative to the volume of the second reactor (200) during the second input was 2.42 g / (min*L).

[0119] Examples 5

[0120] In the above Example 4, the process was simulated in the same manner as in Example 4, except that the splitting ratio of the butadiene monomer at the second input was 77 wt% (23 wt% at the first input).

[0122] Examples 6

[0123] In the above Example 1, the process was simulated in the same manner as in Example 1, except that the input rate relative to the volume of the second reactor (200) during the second input of butadiene monomer was 5.09 g / (min*L).

[0125] Examples 7

[0126] In the above Example 3, the process was simulated in the same manner as in Example 3, except that the input rate relative to the volume of the second reactor (200) during the second input of butadiene monomer was 7.10 g / (min*L).

[0128] Comparative example 1

[0129] As shown in the process flow diagram in FIG. 2, a mixed solution of solvent and styrene monomer (SM) and n-butyllithium were introduced into a first reactor (100) with a capacity of 50 L, and polymerization was started at 40°C or higher. After the polymerization was terminated when the polymerization conversion rate was 99.8% or higher, butadiene monomer (BD) was introduced at 57.7°C to start polymerization.

[0130] At this time, the polymerization was performed in an insulated state in the first reactor (100), without a separate heat removal means at the top. In addition, a mixed solvent of n-hexane and cyclohexane with a cyclohexane content of 87 wt% was used as the solvent.

[0131] Subsequently, after reaching the peak temperature of 118.3 °C during the polymerization of the above-mentioned butadiene monomer, silicon tetrachloride (SiCl4), which is a coupling agent, was added 3 minutes later, and the coupling reaction was terminated after 10 minutes, and by removing the solvent in the polymer solution and the remaining unreacted monomer, a polymer containing styrene-butadiene-styrene triblock copolymer (SBS) was obtained.

[0132] After discharging the polymer from the above reactor, a second polymerization was performed in the same reactor in the manner described above, as shown in the process flow of Fig. 1, to obtain the polymer for the second polymerization.

[0133] The total solid content (TSC) of the SBS copolymer in the polymer for the second polymerization was 18.1 wt%, the content of butadiene blocks in the SBS copolymer was 69.1 wt%, and the content of random polystyrene (random PS) was 4.1 wt%.

[0135] Comparative example 2

[0136] In the above Example 1, the process was simulated in the same manner as in Example 1, except that the butadiene monomer was not divided and added in a second step, but added in a lump sum in the first step to perform polymerization.

[0138] Comparative example Examples 1 2 1 2 3 4 5 6 7 Polymer content (g) 4985 6967 6114 6967 8234 9005 10217 6141 8289 BD polymerization start temperature (°C) 57.7 67.1 63.0 67.1 73.7 78.0 85.2 63.1 74.0 BD 1st input amount (g) 3444 4814 2957 2407 2162 1991 1624 2970 2176 BD polymerization maximum temperature (°C) 118.3 131.4 115.9 110.9 113.8 115.6 115.7 116.3 114.4 BD 2nd input amount (g) - - 1267 2407 3527 4231 5435 1273 3551 BD 2nd insertion time (minutes) - - 10 18 25 35 45 5 10 BD secondary injection rate (g / min) - - 126.7 133.7 141.1 120.9 120.8 254.6 355.1 Polymerization temperature (°C) upon second BD addition - - 110 110 110 110 110 110 110 TSC (weight%) 18.1 25.3 22.2 25.3 29.9 32.7 37.1 22.3 30.1 BD 2nd Input Split Ratio (Weight%) - - 30 50 62 68 77 30 62 Secondary reactor volume (L) 50 50 50 50 50 50 50 50 50 BD input rate relative to secondary reactor volume (g / (min*L)) - - 2.53 2.67 2.82 2.42 2.42 5.09 7.10 note 4.1 wt% random polystyrene produced Long-term operation impossible due to detection of polymers in the condenser Pump transfer impossible when discharging the second reactor Long-term operation impossible due to detection of polymers in the condenser Long-term operation impossible due to detection of polymers in the condenser

[0140] Referring to Table 1, when the polymerization of the SBS triblock copolymer was carried out in a conventional batch reactor (Comparative Example 1), the final SBS product contained 4.1 wt% of random polystyrene, which can be seen as a decrease in the productivity of the SBS product.

[0141] In addition, when polymerization was performed by adding butadiene in a lump sum in the first stage instead of adding it in the first and second stages (Comparative Example 2), the polymerization temperature in the reactor rose to 131.4 ℃ due to a rapid increase in the heat of polymerization, and in order to maintain the polymerization temperature at 110 ℃, the amount of the upper discharge stream of the gaseous phase discharged from the top of the second reactor (200) was controlled, but it was confirmed that fouling occurred in the heat removal device (200) as the second diblock copolymer was discharged together with the gaseous conjugated diene monomer from the top of the second reactor (200).

[0142] In contrast, in the case of the examples in which, when manufacturing the SBS triblock copolymer, the polymerization of styrene monomer and the polymerization of butadiene monomer are performed, the reactors are independently used as the first reactor (100) and the second reactor (200), respectively, and the butadiene monomer introduced into the second reactor (200) is divided into first and second introductions, the butadiene monomer allocated during the first introduction is introduced in a lump sum, while the butadiene monomer allocated during the second introduction is introduced evenly and continuously at an appropriate introduction rate relative to the volume of the second reactor (200), and polymerization is performed while deheating (an adiabatic reaction during the first introduction of butadiene), no random polystyrene is produced in the final SBS product, and the SBS solid content (TSC) in the polymer solution is higher than that of Comparative Example 1, indicating excellent productivity and confirming that energy consumed during desolvation can be reduced. Explanation of the symbols

[0144] 100: First reactor 200: Second reactor 300: Heat removal device

Claims

Claim 1 A step (S10) of polymerizing an aromatic vinyl monomer block in an adiabatic state by introducing an aromatic vinyl monomer into a first reactor; a step (S20) of supplying the discharge stream of the first reactor containing the aromatic vinyl monomer block to a second reactor and introducing a conjugated diene monomer into the second reactor first to polymerize a first diblock copolymer containing the aromatic vinyl monomer block and the first conjugated diene monomer block in an adiabatic state; a step (S30) of introducing a conjugated diene monomer into the second reactor second to polymerize while removing the reaction heat, thereby polymerizing a second diblock copolymer containing the aromatic vinyl monomer block and the second conjugated diene monomer block when the polymerization conversion rate of step (S20) is 90% or more. The method comprises a step (S40) of obtaining a triblock copolymer by introducing a coupling agent into the second reactor after the polymerization of the above step (S30) is completed, wherein the heat removal of the reaction heat in the above step (S30) is performed by condensing a discharge stream containing gaseous conjugated diene monomer vaporized by the reaction heat from the second reactor using a heat removal device and then recirculating it to the second reactor, wherein, relative to the total amount of the first and second conjugated diene monomers introduced, the amount of the first conjugated diene monomer introduced is 30 to 70 weight% and the amount of the second conjugated diene monomer introduced is 30 to 70 weight%, and in the above step (S30), the second conjugated diene monomer introduced is continuously introduced into the second reactor, and the introduction rate of the second conjugated diene monomer introduced relative to the volume of the second reactor is 3.0 A method for manufacturing a block copolymer with a g / (min*L) or less. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A method for manufacturing a block copolymer according to claim 1, wherein the gaseous conjugated diene monomer is condensed to 30 to 45 ℃ and then refluxed to the second reactor. Claim 6 A method for manufacturing a block copolymer according to claim 1, wherein in step (S30), the polymerization temperature in the second reactor is maintained at 100 to 120 ℃. Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 A method for manufacturing a block copolymer according to claim 1, wherein the input rate of the conjugated diene monomer secondarily input relative to the volume of the second reactor is 2.4 to 3.0 g / (min*L). Claim 11 A method for manufacturing a block copolymer according to claim 1, wherein the aromatic vinyl monomer is styrene, the conjugated diene monomer is butadiene, and the triblock copolymer is a styrene-butadiene-styrene triblock copolymer (SBS).

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