JPS6017408B2 - Continuous polymerization method for block copolymers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously producing a block copolymer consisting of a conjugated diene and a vinyl aromatic hydrocarbon.

More specifically, a specific living polymer is produced batchwise using a part of the monomers that form the block copolymer using an organolithium compound as a catalyst, and then the remaining monomer is produced continuously using a living polymer. This invention relates to a method for producing a block copolymer using a combination of batch and continuous polymerization methods. A block copolymer consisting of a conjugated diene and a vinyl aromatic hydrocarbon can exhibit elasticity similar to that of vulcanized natural rubber or synthetic rubber without vulcanization when the vinyl aromatic hydrocarbon content is relatively low. It has the same processability as thermoplastic resin at room temperature and high temperature.
Widely used in footwear, plastic modification, asphalt, and adhesive fields. On the other hand, when the content of vinyl aromatic hydrocarbons is relatively high, thermoplastic resins that are transparent and have excellent impact resistance can be obtained. be. It takes a while.

The method for producing the copolymer has been known for a long time, for example, in Japanese Patent Publication No. 36-19286 and Samurai Publication No. 40-123.
Publication No. 7, Special Publication No. 43-1797y, Publication No. 4 of Tsubaki Publication
It is described in Japanese Patent Publication No. 9-36957, Japanese Patent Publication No. 48-4106, etc. However, all of the methods described in these documents are based on batch polymerization methods, and continuous polymerization methods have been developed due to their advantages in terms of productivity, stability and uniformity of quality, and labor saving in the process. is desired from the viewpoint of industrial manufacturing. Continuous polymerization methods for block copolymers have been studied for a relatively long time, but a method for continuously producing block copolymers with the excellent properties mentioned above on an industrial scale has yet to be found. It has not been.

For example, U.S. Pat. No. 3,356,763 discloses that a mixture of a conjugated diene and a vinyl aromatic hydrocarbon is polymerized with an organolithium compound, and the resulting random copolymer IJ Bing polymer and unreacted monomers are collected in a tubular polymerization vessel. It is described in the method of supplying V to polymerization to obtain a block copolymer. However, this method only yields a type 2 block copolymer consisting of a copolymer block of conjugated diene and vinyl aromatic hydrocarbon and a homopolymer block of vinyl aromatic hydrocarbon when an organic monolithium compound is used as a catalyst. This product shows only extremely low tensile strength in an unvulcanized state.In addition, Japanese Patent Publication No. 49-38029 and Japanese Patent Publication No. 50-1332 disclose that the number of blocks is increased by using an organic monolithium compound as a catalyst. Methods for continuously producing block copolymers having 3 or more have been described, but all of them have the following drawbacks and are still insufficient as industrial production methods.

That is, the former relates to a method of continuously producing a block copolymer from several blocks using additional polymerization vessels connected in series, but the average residence time in each even-numbered polymerization vessel is 4 minutes to 3 minutes. It is essential to set the residence time to a certain degree in order to obtain a block copolymer with excellent properties, and such a limited residence time means that the production amount is less variable. In addition, the latter is characterized in that when forming a polymer block of vinyl-substituted aromatic hydrocarbons, polymerization is carried out under conditions such as to perform lateral coagulation and to prevent upper and lower rope frames. The setting of this method requires a fairly sophisticated polymerization technique, and it is difficult to say that it is an easy method. The present invention was achieved through extensive research into a method for continuously obtaining a block copolymer having properties equal to or superior to those obtained in the above.

That is, according to the present invention, a polymer block containing at least two vinyl aromatic hydrocarbon-based polymer blocks and at least one conjugated hydrogen-based polymer block in an inert hydrocarbon solvent When producing a block copolymer continuously, [al A living polymer having at least one pinyl aromatic hydrocarbon polymer block having a ratio of 1.5 to the number average molecular weight (hereinafter referred to as a reserve polymer block) is produced by a batch method, 'b} Then, In the continuous polymerization region where the remaining monomer is continuously polymerized, one or more polymerization vessels connected in series are used, and at the same time, the prepolymer is continuously supplied to the first polymerization vessel, and at the same time, the prepolymer is continuously supplied to the first or The remaining monomer is continuously supplied to the subsequent polymerization vessel as a monomer mainly composed of vinyl aromatic hydrocarbons and/or a monomer mainly composed of conjugated hydrogen, and continuous polymerization is carried out.
'c- There is provided a method for continuous polymerization of a block copolymer, characterized in that the obtained block copolymer is further reacted with a polyfunctional compound in the state of a living polymer.

The method of the present invention not only allows a block copolymer with excellent tensile strength or impact resistance to be easily obtained in high production quantities, but also (2) has a wide permissible range of residence time in each polymerization vessel, making production easier. (3) It takes a short time to reach a steady state (there is little loss in the initial stage of polymerization, '4) It is possible to polymerize continuously for a long time without producing a gel-like polymer, etc. It has the characteristics of

The present invention will be explained in more detail below.

The greatest feature of the present invention is that the number average molecular weight (hereinafter abbreviated as Mn) is at least 5,000, which is produced in advance by a batch method using some monomers and an organolithium compound as a catalyst.
0, preferably at least 7,000, more preferably at least 9,000, and the ratio of weight average molecular weight (hereinafter abbreviated as Mw) to Mn is less than 1.5, preferably 1.
3 or less, more preferably 1. The object of the present invention is to use a living polymer (prepolymer) having at least one vinyl aromatic hydrocarbon polymer block as a catalyst in a continuous polymerization process.

When Mn and Mw/Mn of the vinyl aromatic hydrocarbon polymer block (hereinafter abbreviated as Ap) contained in the prepolymer deviate from the above range, the mechanical properties, especially the tensile strength, of the final block copolymer obtained Otherwise, it is not preferable because the impact resistance decreases. Mn and Mw/Mn of Ap are determined as is when prepolymerized polystyrene is used, and when the prepolymer is used as a block copolymer after decomposition of the prepolymer with peroxide (L
・M. koltho day etal, J. polymer S
ci. , 1, 429 (1946) directly or indirectly by measuring Ap components collected or Ap monopolymer etc. obtained by polymerizing under the same conditions as the polymerization conditions of Ap using gel permeation chromatography. can be asked for. The content of vinyl aromatic hydrocarbon in the preliminary coalescence is 4% by weight or more, preferably 5% by weight or more, and more preferably 6% by weight or more, for excellent tensile strength or impact resistance. Recommended for obtaining block copolymers. In the present invention, the polymer structure of the prepolymer is not particularly limited, but the following may be cited as a model example. Ap-Lj, (Ap-B
p-nLi, (Bp-ApnLiAp←Bp-ApnLiBp÷Ap-BpnLi (here, Bp is the conjugated diene polymer block and/or the conjugated diene and pinyl aromatic hydrocarbon contained in the prepolymer) represents a random copolymer block, where n is an integer of 1 or more.

In addition, when Bp is a random copolymer or contains a random copolymer portion, the vinyl aromatic hydrocarbon may be distributed uniformly along the polymer chain or may be distributed in a tapered shape. . ) Particularly preferable prepolymers used in the present invention are homopolymers of vinyl aromatic hydrocarbons or Bp
-A living polymer having the structure of -Ap-Li.

The molecular weight of the prepolymer used in the present invention is a number average molecular weight of 5.
,000 to 300,00, preferably 7,000 to 10
0,000, more preferably 2,000 to 50,000.

The reserve combination used in the present invention is produced by a batch method.

Here, the batch method refers to a method in which the monomer is added all at once or in two or more portions and sequentially added to a non-flowing polymerization vessel, and is referred to as batch polymerization, semi-batch polymerization, or a combination thereof. including a polymerization method consisting of The monomer may be added continuously using a pump or the like. Specific methods for polymerizing the prepolymer include methods described in Hakamako Sho 36-19286, Samurai Ko Sho 43-1797y, and the like. The organic lithium compound used in the production of the prepolymer used in the present invention is preferably an organic monolithium compound in which one lithium atom is bonded in the molecule, such as ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium. , sce-butyllithium, te-91 butyllithium, n-bentyllithium, ten-octyllithium, phenyllithium, tolyllithium, butylphenyllithium, cyclohexyllithium, phthylcyclohexyllithium, etc.
Particularly common ones include n-butyllithium, se
Examples include c-butyllithium.

In addition, in the production of prepolymerization, it is possible to perform polymerization without using any solvent, but it is possible to carry out the polymerization without using any solvent, but it is possible to proceed with the reaction uniformly,
For the purpose of preventing local abnormal reactions, it is preferable to use a mixture of one or more inert hydrocarbons as the solvent. The commonly used composition range of monomer and solvent is 5:95 to 90:10, preferably 10:90 to 70.
:30. As the type of solvent, any of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, or any mixture thereof, which will be detailed later, can be used, but if the vinyl aromatic hydrocarbon content of the prepolymer is When the amount exceeds about 75% by weight, it is preferable to use a solvent mainly composed of aromatic hydrocarbons or alicyclic hydrocarbons. This is because a prepolymer having a vinyl aromatic hydrocarbon content exceeding about 75% by weight becomes difficult to dissolve in a solvent mainly composed of aliphatic hydrocarbons. Therefore, solvents containing mainly aliphatic hydrocarbons, i.e., ``50% by weight or more of aliphatic hydrocarbons, more generally 7% by weight,
When using a solvent containing more than 75% by weight, the vinyl aromatic hydrocarbon content of the prepolymer is preferably about 75% by weight or less. Next, the continuous polymerization region in the method of the present invention will be explained in detail.

In the continuous polymerization region of the present invention, one polymerization vessel or two or more polymerization vessels connected in series are used, the first polymerization vessel is continuously supplied with the prepolymer, and the first or In the subsequent polymerization vessel, the remaining monomers are continuously combined and polymerized as monomers mainly composed of vinyl aromatic hydrocarbons and/or monomers mainly composed of conjugated hydrogen, and the block copolymer is continuously produced. Manufacture.

In addition, in the present invention, if necessary, a monomer mainly composed of vinyl aromatic hydrocarbons may be further supplied to at least one of the polymerization vessels in the continuous polymerization region through one or more V supply ports attached to the polymerization vessel. Polymerization can also be carried out by continuously supplying a monomer mainly consisting of and or a conjugated diene. It is preferable that the monomer mainly composed of vinyl aromatic hydrocarbon and the monomer mainly composed of conjugated hydrogen supplied to the continuous polymerization zone are polymerized in substantially separate polymerization zones, but if necessary, unreacted monomers can be removed. It is also possible to supply the contained polymer mixture to the next polymerization vessel or the next polymerization zone and copolymerize it with the newly supplied monomer. Note that the monomers supplied to the continuous polymerization zone are polymerized in substantially separate polymerization zones under conditions in which each monomer is not randomly copolymerized, preferably at least 5% by weight of each monomer, and further Preferably, it means that 7% by weight or more is polymerized under conditions where random copolymerization does not occur. Such conditions include polymerizing each monomer in separate polymerization vessels, or even in the case of the same polymerization vessel, installing a partition such as a perforated plate in the polymerization vessel to prevent uniform mixing of each monomer, or Easily set by methods such as sufficiently separating the positions of each monomer supply V inlet to prevent uniform mixing of monomers, or sufficiently increasing the linear velocity of the contents of the polymerization vessel in the exit direction to prevent back mixing. be able to. Examples of polymerization forms in the continuous polymerization region of the present invention include the following polymerization forms, but it goes without saying that the present invention is not limited to these polymerization forms.

Polymerization form '1 - Using two or more polymerization vessels connected in series, the first polymerization vessel is continuously supplied with prepolymer and skiving polymer, and at the same time, the odd-numbered polymerization vessels are supplied mainly with conjugated gene. (or monomers mainly composed of vinyl aromatic hydrocarbons) are continuously combined and polymerized, and the polymer obtained in the odd-numbered polymerization vessel is continuously added to the even-numbered polymer. At the same time, a monomer mainly composed of vinyl aromatic hydrocarbon (or a monomer mainly composed of conjugated diene) is continuously supplied to the polymerization vessel for polymerization.

Polymerization mode ■ In the method of {1}, a polymer mainly containing a conjugated gene further from at least one supply port attached to the side of at least one odd-numbered polymerization vessel and/or at least one even-numbered polymerization vessel and/or monomers mainly composed of vinyl aromatic hydrocarbons are continuously supplied and polymerized.

Polymerization mode '3' One polymerization vessel is used, and the living polymer of the reserve polymer and the monomer mainly composed of conjugated diene or the monomer mainly composed of vinyl aromatic hydrocarbon are continuously supplied to the polymerization vessel. to polymerize.

Polymerization form (4) In the glue method, a monomer mainly composed of conjugated gene and/or a monomer mainly composed of vinyl aromatic hydrocarbon is continuously supplied through at least one supply port attached to the side of the polymerization vessel. Polymerize by feeding directly.

In the present invention, IJ Bing polymers of block copolymers having various block structures are continuously produced by roughly adjusting the block structure of the prepolymer, the number of polymerizers in the continuous polymerization zone, and the monomer supply form in the continuous polymerization zone. can do.

Examples of the block structure are as follows. (A-BkinLi, A÷B-A★nLi, B÷.A
-BkinLi, B-AmountB←AnanLi (here, A is a polymer block mainly composed of vinyl aromatic hydrocarbon, and B is a polymer block mainly composed of conjugated hydrogen.

The boundary between A block and B block does not necessarily need to be clearly distinguished. n is an integer of 1 or more. ) In this specification, the polymer block A mainly composed of vinyl aromatic hydrocarbons is a polymer block in which the content of vinyl aromatic hydrocarbons exceeds 5% by weight; A polymer block consisting of a copolymer portion with hydrogen and a vinyl aromatic hydrocarbon polymer portion, or a polymer block consisting only of a vinyl aromatic hydrocarbon polymer portion.

Moreover, the polymer block B mainly composed of conjugated gene is a polymer block in which the content of conjugated gene is 50% or more by polymerization, and the copolymer part of conjugated gene and pinyl aromatic hydrocarbon and vinyl aromatic hydrocarbon A polymer block composed of a hydrogen polymer portion or a polymer block composed only of a conjugated hydrogen polymer portion. In the optional copolymer portions of block A and block B, the vinyl aromatic hydrocarbon may be distributed uniformly or tapered. In the present invention, the block copolymer continuously polymerized in the continuous polymerization region is reacted in the state of a living polymer with a polyfunctional compound to be described in detail later to produce a block copolymer having the block structure as shown below. Polymers can be produced. The reaction between the living polymer and the polyfunctional compound can be carried out continuously, or after storing a certain amount of the living polymer, the polyfunctional compound corresponding to the amount of stored polymer can be added and the reaction can be carried out in batches. good. ((A-Bunyom10.X, [A÷B
-Aonyom10. X [B ÷ A-B nai X' [B-Af
B-A''★SaichisendeX (Here, A, B and n are the same as above.

× indicates a residue of a polyfunctional compound, and m indicates an integer of 1 or more.
) In the present invention, the polymerization in the continuous polymerization region can be carried out without using any solvent, but it is possible to proceed the reaction uniformly and prevent local abnormal reactions, such as the formation of gel-like polymers, or to For the purpose of reducing the viscosity of the combined solution, it is preferred to use a mixture of one or more inert hydrocarbons as the solvent. The general composition range of monomer and solvent used is 5:95 to 90:1, preferably 10:90 to 70:30, and more preferably 15:85.
~50:50. As for the type of solvent, any of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, or any mixture thereof can be used, as in the case of producing the prepolymer. However, from the standpoint of industrial production, when recovering the block copolymer by removing the solvent from the finally obtained block copolymer solution, aliphatic hydrocarbons, which generally have a low latent heat of vaporization, are mainly used. It is preferable to use a solvent such as this because the energy consumption for solvent distillation is small. However, when using a solvent mainly composed of aliphatic hydrocarbons, it should be noted that the vinyl aromatic hydrocarbon content of the polymer being polymerized in the continuous polymerization zone is not more than about 75% by weight, preferably 7% by weight. The problem is to select polymerization conditions so that the amount is less than or equal to % by weight. When the vinyl aromatic hydrocarbon content exceeds about 75% by weight, the polymer becomes insoluble in solvents mainly composed of aliphatic hydrocarbons and precipitates and separates from the polymerization system.
This is undesirable because it accumulates in the polymerization vessel, making long-term continuous polymerization impossible. In the method of the present invention, the average residence time of each polymerization vessel in the continuous polymerization region is not particularly limited, but the stability of long-term continuous polymerization operation, productivity, and prevention of deterioration of physical properties of the block copolymer due to deactivation of the living polymer are etc., for 3 minutes to 5 hours, preferably 5 minutes to 3 hours, more preferably 10 minutes to 2 hours. In addition, the polymerization temperature of each polymerization vessel is set based on the relationship between the average residence time of each polymerization vessel and the polymerization conversion rate of the monomer at the outlet of each polymerization vessel, but it is also determined to ensure productivity, prevention of living polymer deactivation, etc. Generally, 10qo to 180oo, preferably 30qo to 140q
o, more preferably in the range of 50 pm to 120 qo. It is desirable that the atmosphere in each polymerization vessel be sufficiently replaced with an inert gas such as nitrogen gas. The pressure in each polymerization vessel is not particularly limited, as long as it is within a pressure range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization overflow range. Furthermore, each polymerization vessel contains impurities that may inactivate the living polymer, such as water, oxygen,
Care must be taken to avoid contamination with carbon dioxide gas, etc. In the method of the present invention, the polymerization vessel used in the continuous polymerization region may be a cell type polymerization vessel, a tower type polymerization vessel, a tube type polymerization vessel, etc., and is not particularly limited. It is preferable to use a polymerization vessel for polymerizing monomers mainly composed of vinyl aromatic hydrocarbons in which L/○ is about 2 or more, preferably 4 or more, and more preferably 8 or more.

Here, L means the length between the upper tangential line and the lower tangential line of the polymerization vessel, and D
means the inner diameter of the polymerization vessel. In addition, the above-mentioned polymerization form '2'
Alternatively, in the method of '41, it is preferable to use a polymerizer having an L/D of about 4 or more, preferably 6 or more, and more preferably 10 or more. In this way, a polymerization vessel with a relatively large L/○ is recommended when the molecular weight distribution of the polymer blocks formed in each polymerization vessel is made relatively uniform, or when each polymerization vessel has multiple supply Vs. This is to facilitate polymerization operability when the monomers supplied from the feed ports are polymerized in substantially separate polymerization regions. The upper limit of L no D is not particularly limited, and even those with extremely large L/○ such as loop type polymerization vessels can be used, but from an industrial perspective, 50 or less is preferable from the viewpoint of polymerization operability and cleaning workability inside the polymerization vessel. . There are no particular limitations on the device used in the polymerization vessel, and a polymerization vessel without a hatching device may be used. However, in general, it is preferable to use a polymerization vessel equipped with a clear frame diamond in consideration of uniformity of the polymerization reaction, removal of reaction heat, and prevention of local abnormal reactions. Any type of rope layer can be used, such as turbine type, screw type, anchor type, static type, etc. Furthermore, a perforated plate, a baffle plate, etc. may be provided in the polymerization vessel as necessary. In the method of the present invention, the reactor for reacting the block copolymer obtained in the continuous polymerization zone with a polyfunctional compound in the state of a living polymer is particularly suitable if the reaction is carried out substantially uniformly. There are no restrictions, and examples include tank-type reactors and tower-type reactors with the same shape as the polymerization vessel described above, fixed container mixers such as trough-type, hopper-type, and pan-type, and polymer solution transfer piping. An in-line mixer, etc. that is partially equipped with a thickening device can be used.

Next, an embodiment of the present invention will be described based on the flows shown in FIGS. 1, 2, and 3.

In these figures, valves, pumps, pressure gauges, jackets for controlling the polymerization temperature controlled by a heat exchange medium such as steam or water, heat exchangers for controlling the temperature of the combined monomers, etc. are omitted. In Fig. 1, a prepolymer (living polymer) that has been polymerized in advance is stored in a storage tank T, and during continuous polymerization, if necessary, it can be produced by another polymerization equipment or the living polymer can be added sequentially or continuously. It is also possible to supply the storage tank T at the same time.

Prepolymer (living polymer) stored in storage tank T
is continuously supplied to the polymerizer R-1 through the pipe 1. Further, the conjugated gene B and/or the vinyl aromatic hydrocarbon A monomer and, if necessary, the solvent S are continuously supplied to the polymerization vessel R-1 through a pipe 2. The polymer (living polymer) polymerized in the polymerization vessel R-1 is continuously taken out and supplied to the reactor C where it is mixed with the polyfunctional compound F. Thereafter, the block copolymer is recovered by being supplied to a step of adding stabilizers and the like, a step of recovering a solvent, and the like. In addition, in FIG. 2, polymerizers R-1 and R are used as polymerizers in the continuous polymerization region.
-2 is shown as an example.

Polymer polymerized in polymerization vessel R-1 (living polymer)
is continuously supplied to the polymerization vessel R-2 through a pipe 3, and monomers B and/or A and, if necessary, a solvent S are continuously supplied to the polymerization vessel R-2 through a pipe 4. The polymer (living polymer) polymerized in the polymerization vessel R-2 is supplied to the reaction step with the polyfunctional compound F in the same manner as in FIG. On the other hand, in FIG. 3, monomer B and/or A and, if necessary, solvent S are supplied to pipes 7 and 10 from the supply port attached to the side of the polymerization vessel in the continuous polymerization region.
continuously supplied through.

The monomers supplied to the polymerization vessels R-3 and R-4 through the pipes 6 and 9 undergo a substantial reaction in the region between the bottom and side supply ports of each polymerization vessel, and The monomer fed through the reactor is controlled so that a substantial reaction proceeds in the region between the side feed port and the top of the polymerizer. It should be noted that FIGS. 1, 2, and 3 explain embodiments of the present invention more specifically, and it goes without saying that the scope of the present invention is not limited thereto. In the method of the present invention, the ratio of the amount of monomers forming the prepolymer supplied to the continuous polymerization zone to the total amount of monomers supplied to the continuous polymerization zone is 90/10 or less, preferably 80/20 or less. , more preferably 60/4
It is less than or equal to 0.

If the ratio of the amount of prepolymer supplied to the continuous polymerization zone to the total amount of monomers supplied exceeds 90/10, the proportion of polymerization in the continuous polymerization zone will decrease, so the productivity improvement effect of continuous polymerization will be small. It's very desirable. In addition, there is no particular restriction on the lower limit of the ratio of the combined amount of prepolymer supplied to the continuous polymerization region to the total V supply amount of monomers, but 5/9
5 or more, preferably 10/90 or more, more preferably 1
It is preferable to carry out the polymerization in the range of 5/85 or more from the viewpoint of controllability of the polymerization operation in the continuous polymerization region of the present invention and stability of physical properties of the finally obtained block copolymer. In the method of the present invention, the vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is determined by the vinyl aromatic hydrocarbon content in the prepolymer and the amount supplied to the continuous polymerization region. can be adjusted by the vinyl aromatic hydrocarbon content in the monomer fed in the continuous polymerization zone and its feed amount, and is generally 5 to 50%.
95% by weight, 10-9% by weight, more preferably 15-9% by weight
It is 85% by weight.

The vinyl aromatic hydrocarbon content in the block copolymer is 5
When the content is 60% to 95% by weight and preferably 55% by weight or less, a thermoplastic elastomer with excellent tensile strength and elasticity is obtained in an unvulcanized state, and 60% to 95% by weight, preferably 65% to
When the amount is 85% by weight, a thermoplastic resin with excellent transparency and impact resistance can be obtained. Further, the Mn of the finally obtained block copolymer is 10,000 to 1,000,00, preferably 30,000 to 500,000. If it is smaller than this range, the mechanical strength, such as tensile strength, impact resistance, etc. of the finally obtained block copolymer will decrease, and if it is larger than this range, the living polymer will be deactivated during continuous polymerization. This is not preferable because it becomes substantially difficult to prevent the influence. In addition, in the present invention, the molecular weight of each polymer block formed in the continuous polymerization region is adjusted by adjusting the amount of active ends and monomers of the living polymer integrated into the polymer block forming region and the mixability in the polymerization vessel. It can be done by doing this. Next, the monomers, solvents, etc. used in the method of the present invention will be explained.

In the present invention, the monomer mainly composed of conjugated genes is
A mixture of a conjugated diene and a vinyl aromatic hydrocarbon containing 5% by weight or more of conjugated diene, or a monomer containing only a conjugated diene, and a monomer mainly composed of a pinyl aromatic hydrocarbon is a vinyl aromatic hydrocarbon. or a monomer of vinyl aromatic hydrocarbon alone, containing more than 5% by weight of conjugated diene and vinyl aromatic hydrocarbon.

Note that the mixture of the conjugated diolefin and the vinyl aromatic hydrocarbon does not necessarily require that the two monomers be mixed in advance; they can be mixed separately as long as the conjugated diolefin and the vinyl aromatic hydrocarbon are copolymerized. It may also be supplied from the Kakehiroguchi. The conjugated gene used in the present invention is 1
Diolefins having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl, -1,3-butadiene (isoprene), 2,3-dimethyl, -1,3-butadiene, 1,3-bentadiene, , 3-hexadiene, etc., but particularly common ones include 1,3-hexadiene, etc.
- Examples include butadiene and isoprene.

These may be used not only as a single type but also as a mixture of two or more types. The vinyl aromatic hydrocarbons used in the present invention include styrene, methylstyrene, ethylstyrene, p-ten-butylstyrene, dimethylstyrene, Q
- Methylstyrene, vinylnaphthalene/vinylanthracene, etc. Particularly common are styrene, Q-
Examples include methylstyrene. Not only one of these, but also two
It may be used as a mixture of more than one species. When a solvent is used in the method of the present invention, solvents include butane, benzane, aliphatic hydrocarbons such as hexane, isobentane, heptane, octane, isooctane, cyclobentane, methylcyclobentane, cyclohexane, methylcyclohexane, ethylcyclohexane, etc. Alicyclic hydrocarbons or aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, etc. can be used.

These may be used in combination depending on the purpose. In addition, when using a solvent mainly composed of aliphatic hydrocarbons in the method of the present invention, it is necessary to use a solvent containing 50% by weight of aliphatic hydrocarbons.
It means a solvent containing the above. A small amount of a polar compound may be added to these solvents to speed up the polymerization rate, or the copolymerization reactivity ratio of the conjugated diene and vinyl aromatic hydrocarbon may be changed to give the final block copolymer the desired structure. It can also be made into a polymer. Examples of these polar compounds include ethers, amines, thioethers, phosphine and phosphoramide. Examples of suitable ethers are dimethyl ether, diethyl ether, diphenyl ether and tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether. Examples of the amines that can be used include tertiary amines such as trimethylamine, triethylamine, and tetramethylethylenediamine, as well as cyclic tertiary amines. Phosphines and phosphoramides include triphenylphosphine and hexamethylphosphoramide. The amount of these polar compounds added varies greatly depending on the type of polar compound used, the amount of active sites in the living polymer, and the polymerization temperature, but in the continuous polymerization region of the method of the present invention, vinyl aromatic hydrocarbon polymers with Mn of at least 5000 are used. It is necessary to limit the amount added so that at least one coalesced block is formed. The polyfunctional compound used in the method of the present invention is a compound having at least two sites in the molecule that react with the active sites of the living polymer, such as halogen groups, epoxy groups, ester groups, acid anhydride groups, ketone groups, etc. It is a compound containing at least two arbitrary functional groups selected from a group consisting of a group consisting of an aldehyde group, an isocyanate group, an imino group, a vinyl group, and a vinylidene group.

Such compounds include, for example, polyhalides, polyepoxides, polyesters, polyanhydrides,
Included are polyketones, polyaldehydes, polyisocyanates, polyimines (polyaziridinyl compounds), polyvinyl compounds, and the like. These compounds may contain two or more types of functional groups, such as a combination of epoxy and aldehyde groups. Specific examples of polyfunctional compounds include dichloromethane, dibromomethane, dibromoptan, dichlorosilane, chloroform,
Epoxidized hydrocarbon polymers such as trichlorosilane, carbon tetrachloride, carbon tetrabromide, silane tetrachloride, silane tetrabromide, tin tetrachloride, tin tetrabromide, epoxidized polybutadiene, epoxidized soybean oil and epoxidized Epoxidized vegetable oils such as linseed oil, carboxylic acid esters such as diethyl succinate and glycerin stearate,
Examples include acid anhydrides such as maleic anhydride and styrene/maleic anhydride copolymers, divinylbenzene, and tetravinylsilane.

In addition, in the method of the present invention, "1,2-ptadiene, vinyl acetylene, cyclobentadiene, primary and secondary
Antigelation agents such as grade amines, butyl chloride, butyl bromide, organic sulfonates, and the like can also be used.

These are generally 1% based on the total amount of monomer and solvent.
Hereinafter, it is preferably used in an amount of 0.5% or less. In the method of the present invention, the block copolymer continuously produced in the continuous polymerization region is treated with a polymerization terminator such as water, alcohols, organic acids, and inorganic acids to deactivate the active sites of the living polymer, as necessary. Inactivation is achieved by adding sufficient amounts to

At this time, by appropriately selecting a polymerization terminator such as reacting carbon dioxide, alkylene oxide, alkylene sulfide, etc. instead of water or alcohol, -O
Block copolymers having various functional groups such as H, -SH, -COO, -COC1, -S03, -C...N at their terminals can be obtained. If necessary, various stabilizers can be added to the block copolymer for the purpose of improving heat resistance, film resistance, etc. Methods of recovering the block copolymer from the block copolymer solution obtained by the method of the present invention include, for example, a method of recovering the block copolymer by precipitation using a precipitating agent such as methanol, and a method of recovering the block copolymer by precipitation using a precipitating agent such as methanol. Any conventionally known method can be used, such as a method in which the copolymer is recovered by evaporating the solvent, or a method in which the block copolymer solution is dispersed in water, and the copolymer is recovered by blowing water vapor to remove the solvent by heating. method can be adopted.

The block copolymer obtained by the method of the present invention can be subjected to various modifications such as hydrogenation, halogenation, hydrohalogenation, or introduction of carpoxyl groups, ester groups, nitrile groups, sulfonic acid groups, etc. through chemical reactions. You can measure the quality.

Furthermore, the block copolymer may contain various additives as necessary, such as inorganic fillers such as calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, clay, talc, glass beads, and glass fibers, and organic reinforcing agents such as carbon black. , organic fibers such as carbon fibers and synthetic fibers, adhesives such as coumaronindene tree paper and terbene resin, crosslinking agents such as organic peroxides, inorganic peroxides, and sulfur, paraffinic, naphthenic and aromatic oils, various pigments, and dyes. It is also possible to use appropriate amounts of a retardant, an antistatic agent, a lubricant, a plasticizer, other fillers, or a mixture thereof. Applications of the block copolymer obtained by the method of the present invention Taking advantage of its properties as a thermoplastic elastomer or thermoplastic resin, it has a wide range of uses. Examples include rubber thread, hoop, etc.
Extruded products such as windows, windows, sheets, films, molded products made from extruded sheets aged in vacuum, compressed air, etc., footwear,
Injection molded products such as containers, blow molded products such as gun accessories and household goods, compression molded products such as packing, sheets, plates, etc., or various types of packaging such as adhesives as solutions, latex dispersed in water, and films. It is also used for Furthermore, the block copolymer may be mixed with natural rubber or various synthetic rubbers in any ratio, or one of various thermoplastic resins such as polyethylene, polypropylene, polystyrene, high-impact polystyrene, acrylonitrile-butadiene-styrene copolymer, etc. Alternatively, it can be used as a useful material to modify the mixture by mixing it with a mixture of two or more types.
EXAMPLES The present invention will be explained in more detail with reference to Examples below, but it goes without saying that the scope of the present invention is not limited to these Examples.

Examples 1 to 3 and Shark Examples 1 and 2 Using a living polymer of polystyrene obtained in a cyclohexane solution using n-butyllithium as a catalyst, the first
Continuous polymerization was carried out using the continuous polymerization method shown in the figure.

First, in order to produce a living polymer of polystyrene, a cyclohexane solution containing previously purified and dried styrene at a concentration of 2% by weight was charged into a stainless steel polymerization vessel equipped with a condenser and internally purged with nitrogen gas. Then, n-butyllithium was added and polymerization was carried out at 50:00 for 2 hours.

The amount of catalyst added was adjusted so that the Mn of the resulting polystyrene would be the value shown in Table 1. Mw/Mn of the polystyrene obtained by this method was about 1.15. Further, in order to obtain polystyrene with a wide molecular weight distribution, a portion of the cyclohexane solution of styrene and a portion of the catalyst were each divided into several portions and added sequentially to polymerize. By this method, polystyrene living polymers having Mw/Mn as shown in Table 1 were produced. The polymerization vessel used here was used as a storage tank T in the next continuous polymerization process. In the continuous polymerization process, L
/D is about 12, polymerization reactor R-1 with a stainless steel hawker
used as.

The living polymer of polystyrene and butadiene were each continuously supplied at a weight ratio of 30:70 to the polymerization vessel R-1, which had been internally purged with nitrogen gas and then overflowed to a predetermined temperature. Butadiene was supplied as a 20% by weight cyclohexane solution. Continuous polymerization was carried out by setting the average residence time in the polymerization vessel R-1 to about 45 minutes and the polymerization temperature to about 90 qo on average. Under these conditions, the polymerization conversion rate of butadiene at the exit of the polymerization vessel was about 1% or more. The block copolymer continuously sent out from the polymerization vessel R-1 was supplied as a living polymer to the next reactor C, and an equivalent amount of dimethyldichlorosilane was reacted with the active sites of the living polymer.

Thereafter, di-te-butyl-p-cresol and trisnonylphenyl phosphite were added as stabilizers to the block copolymer solution continuously taken out from reactor C, and 0.5 parts by weight each per 100 parts by weight of the block copolymer. After the addition, the solvent was removed by heating to obtain a block copolymer. The styrene content of the obtained block copolymer was approximately 29
~31% by weight, block styrene content approximately 28-31
Weight %, melt flow index (ASTM D-1
238-5, condition G) was approximately 4-8. The physical properties of the obtained block copolymers are shown in Table 1, but those that were continuously polymerized using polystyrene living polymers with either Mn or Mw/Mn outside the scope of the present invention as prepolymers had tensile strength. It is clear from the results in Table 1 that the strength is extremely reduced.

In the continuous polymerization according to the method of the present invention, the polymerized block copolymer solution starts to come out from the outlet of reactor C, and at a relatively early point when the block copolymer solution starts to come out from the exit of polymerization vessel R-2. A block copolymer exhibiting almost desired physical properties was produced, and a steady state was reached after about 45 minutes, after which the block copolymer having the physical properties shown in Table 1 was produced stably and continuously. Obtained.

Continuous polymerization using the method of the present invention was carried out for 10 consecutive days, and stable operation continued without any problems such as clogging of piping due to the formation of gel-like substances or large fluctuations in physical properties. We were able to. Table 1 Note 1) Tensile strength, elongation, tensile stress at 300% elongation, and hardness were measured according to JISK 6301K.

Examples 4 and 5 and Comparative Example 3 Using an IJ ping polymer of a block copolymer consisting of (polybutadiene)-(polystyrene) obtained in an n-hexane solvent using n-butyllithium as a catalyst, the first
Continuous polymerization was carried out using a continuous polymerization apparatus such as the flow sheet shown in the figure.

First, in order to produce IJ Bing polymer, which is a block copolymer, an n-hexane solution containing pre-purified and dried butadiene at a concentration of 2% by weight was placed in a stainless steel polymerization vessel equipped with a concentrator and internally purged with nitrogen gas. was charged, then n-butyllithium was added as a catalyst and the mixture was heated to 90
Polymerized for minutes.

Thereafter, an n-hexazole solution containing styrene at a concentration of 2% by weight was added, and the polymerization was continued for 2 hours at 50 CO.
The amount of monomer and catalyst added is based on the molecular weight and styrene content of the polystyrene block of the block copolymer.
I adjusted it so that it looks like the table. The same polymerization vessel as in Example 1 was used for the continuous polymerization process. Butadiene was supplied as a 2% by weight solution in n-hexane. The same method as in Example 1 was carried out, except that the ratio of prepolymer and butadiene to be supplied to the polymerization vessel V was as shown in Table 2, and the polyfunctional compound used in reactor C was tetrachlorinated silane. Continuous polymerization was performed. The styrene content and block styrene of the finally obtained block copolymer were almost the same as in Example 1.
Moreover, the melt index was 0.5-2. In addition, as Comparative Example 3, continuous polymerization was carried out in the same manner as above using a random copolymer sliding polymer having a styrene content of 50% by weight instead of a block copolymer sliding polymer having a styrene content of 100% by weight. However, a block copolymer with excellent tensile strength in an unsulfurized state could not be obtained.

Example 6 Same as Example 1 except that the ratio of prepolymer and butadiene supplied to the polymerization vessel in Example 1 was as shown in Table 2, and tetrachlorinated silane was used as the polyfunctional compound. Continuous polymerization was carried out using the method described above.

The styrene content of the finally obtained block copolymer is approximately 39 to 41% by weight, and the block styrene content is approximately
The melt flow index was 4 to 8, and the physical properties were as shown in Table 2. Table 2 Examples 7 and 8 Block copolymers having styrene contents of 7% by weight and 8% by weight were continuously polymerized in the same polymerization form as in Example 6, and the results are shown in Table 3.

Table 3 Note 2) The physical properties of the above examples were measured according to JIS-K6871.

[Brief explanation of drawings]

FIG. 1 is a continuous polymerization flow sheet showing an example of an embodiment of the method of the present invention. FIG. 2 is a continuous polymerization flow sheet showing another example of an embodiment of the method of the present invention. FIG. 3 is a continuous polymerization flow sheet showing still another example of the embodiment of the method of the present invention. T
...Storage tank, R-1, R-2, R-3, R-4...
Polymerization vessel, C...Reactor, 1-10...Piping, B...
... Conjugated Jen "A... Vinyl aromatic hydrocarbon,
S: solvent, F: polyfunctional compound,
P…. ...Flock copolymer. Plan 1 figure 2 figure Tsutomu 3 figure

Claims (1)

[Scope of Claims] 1. A block containing at least two vinyl aromatic hydrocarbon-based polymer blocks and at least one conjugated diene-based polymer block in an inert hydrocarbon solvent. When producing a copolymer continuously, (
a) Using a part of the monomers forming the block copolymer, using an organolithium compound as a catalyst in advance, the number average molecular weight is at least 5,000 and the ratio of the weight average molecular weight to the number average molecular weight is less than 1.5. A living polymer (hereinafter referred to as a prepolymer) having at least one certain vinyl aromatic hydrocarbon polymer block is produced by a batch method, and (b) in a continuous polymerization region in which the remaining monomers are continuously polymerized, 1. Using two or more polymerization vessels connected in series, the prepolymer is continuously supplied to the first polymerization vessel, and at the same time, the remaining monomer is supplied to the first or subsequent polymerization vessels. Continuously supply monomers mainly composed of aromatic hydrocarbons and/or monomers mainly composed of conjugated dienes for continuous polymerization, and (c) further polyfunctionalize the obtained block copolymer in the state of a living polymer. A continuous polymerization method for block copolymers characterized by reaction with a compound. 2. The method according to claim 1, wherein the prepolymer is a living polymer or copolymer having a vinyl aromatic hydrocarbon content of 40% by weight or more. 3. The method of claim 2, wherein the prepolymer is a living polymer of vinyl aromatic hydrocarbon polymer. 4 Claims in which the prepolymer is a living polymer of a block copolymer consisting of a polymer block mainly composed of one conjugated diene and one polymer block mainly composed of vinyl aromatic hydrocarbon. The method described in Section 2. 5. The method according to claim 4, wherein the living polymer is a block copolymer having a vinyl aromatic hydrocarbon content of more than 60% by weight. 6. The method according to claim 1, wherein a living polymer obtained by a polymerization method consisting of batch polymerization, semi-batch polymerization, or a combination thereof is used as the prepolymer. 7 In the continuous polymerization region, a monomer mainly consisting of conjugated diene is continuously supplied and polymerized to the odd-numbered polymerization reactor of two or more polymerization reactors connected in series, and the monomer obtained in the odd-numbered combined reactor is Claim 1, wherein a living polymer of the polymer is continuously fed to an even-numbered polymerization vessel, and at the same time, a monomer mainly composed of vinyl aromatic hydrocarbon is continuously fed to the polymerization vessel for polymerization. Method. 8. The method according to claim 1, wherein one polymerizable group is used in the continuous polymerization region. 9 The ratio of the amount of monomers forming the prepolymer to the amount of monomers that are continuously polymerized in the continuous polymerization region is 5:95 to 9.
The method according to claim 1, wherein the ratio is 0:10 (weight ratio). 10. The method according to claim 1, wherein the vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is 5 to 95% by weight. 11 The vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is 5% by weight or more, 6
11. The method of claim 10, wherein the amount is less than 0% by weight. 12 The vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is 60 to 95% by weight.
11. The method according to claim 10. 13 The polyfunctional compound has at least two arbitrary functional groups selected from halogen groups, epoxy groups, ester groups, acid anhydride groups, ketone groups, aldehyde groups, isocyanate groups, imino groups, vinyl groups, and vinylidene groups. 2. The method according to claim 1, wherein the compound contains