JPS6017407B2 - Continuous production method of block copolymer - Google Patents

Description

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

More specifically, a specific living polymer is produced in advance by a batch method 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 yielding 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 is widely used in the fields of footwear, plastic modification, asphalt, and adhesives because it has the same processability as thermoplastic resins at room temperature and at high temperatures. On the other hand, when the vinyl aromatic hydrocarbon content is relatively high, thermoplastic resins that are transparent and have excellent impact resistance can be obtained, so their usage has recently been increasing, mainly in the food packaging container field. . Methods for producing such block copolymers have been known for a long time, and are disclosed, for example, in Japanese Patent Publications No. 36-19286 and Japanese Patent Publication No. 40-2379.
Publication No. 8, Special Publication No. 43-17979, Publication of Tsubaki Publication No. 49
It is described in JP-A-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. Although continuous polymerization methods for flock copolymers have been studied for a relatively long time, no method has yet been found to continuously produce block copolymers with the excellent properties mentioned above on an industrial scale. 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 a reactive monomer are placed in a tubular polymerization vessel. It is described in the method of supplying and polymerizing to obtain a block copolymer. However, with this method, when an organic monolithium compound is used as a catalyst, only 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 can be obtained. First, this material exhibits extremely low tensile strength in its raw state. Also, Special Publication No. 49-38029 and Mochiko Sho 5
Publication No. 0-1332 describes a method for continuously producing a block copolymer having three or more blocks using an organic monolithium compound as a catalyst, but all of them have the following drawbacks. Is it still insufficient as an industrial manufacturing method?

That is, the former relates to a method for continuously producing a block copolymer consisting of blocks of water using polymerization vessels connected in series, but the average residence time in each even-numbered polymerization vessel is 4 minutes or more. Setting the residence time to 30 minutes is an essential requirement in order to obtain a block copolymer with excellent properties, and such a restriction on the residence time means that the production amount is variable by 4 mm. In addition, the latter is characterized in that when forming a polymer block of pinyl-substituted aromatic hydrocarbons, polymerization is carried out under conditions that perform lateral cross-over and prevent upper and lower cross-over. A fairly sophisticated polymerization technique is required to set this, and it is difficult to say that it is an easy method. The present inventors have overcome these problems in the conventional continuous polymerization of block copolymers, and at the same time have created a block copolymer that has properties equivalent to or better than block copolymers obtained by batch polymerization. The present invention was arrived at after intensive study on a method for continuously obtaining it. That is, according to the present invention, at least two vinyl aromatic hydrocarbon-based polymer blocks and at least one
When continuously producing a floc copolymer having a polymer block mainly composed of {a}
Using a part of the monomers forming the block copolymer in advance and using an organolithium compound as a catalyst, 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 1.5 or more. A living polymer having at least one certain vinyl aromatic hydrocarbon polymer block (
Hereinafter referred to as reserve army combination) is produced by a batch method, {b
} After that, in the continuous polymerization region where the remaining monomers are continuously polymerized, one or more polymerization vessels connected in series with L/D (L is the length of the polymerization vessel, and D is the inner diameter of the polymerization vessel) is 6 or more are used. The prepolymer is continuously added to the first polymerization vessel, and at the same time, the remaining monomer is added to the first and subsequent polymerization vessels. At least a pinyl aromatic hydrocarbon polymer block is continuously supplied as a monomer mainly composed of diene and has a number average molecular weight of at least 5,000 and a ratio of weight average molecular weight to number average molecular weight of less than 1.5. Continuous polymerization is carried out under conditions such that one polymer is formed.

Provided is a continuous method for producing a block copolymer characterized by the following.

By the method of the present invention, it is possible to continuously and easily obtain a block copolymer having excellent mechanical properties, particularly tensile strength.

In addition, the method of the present invention has a wide permissible range of residence time in each polymerization vessel, high variability in production volume, (1) short time to reach a steady state, and (3) low loss in the initial stage of polymerization.
- It has the characteristics of being capable of continuous polymerization for a long time without producing a gel-like polymer. 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) of at least 5,00, preferably at least 7,000, is produced by a batch method using some monomers and an organolithium compound as a catalyst. Preferably, it is 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 (reserve polymer) 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 prepolymerization is made of block copolymer, after the prepolymerization is decomposed with peroxide (L
M. kolthoffetal, J. poMmerSc.
i. , 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 the vinyl aromatic hydrocarbon in the prepolymer is 40% by weight or more, preferably 5% by weight or more, and more preferably more than 6% by weight, so that the prepolymer has 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-Li, (Ap-BpnanLi,
(Bp-ApchinLiApkiBp-ApnanLiBpf
Ap-BpnanLi (where Bp represents a conjugated gen polymer block and/or a random copolymer block of conjugated gen and vinyl aromatic hydrocarbon contained in the prepolymer, and 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 or more preferably 7,000 to 10
0,000, more preferably 9,000 to 50,000
It is.

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 sequentially in two or more portions in 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 polymerization methods for the prepolymer include methods described in Hakama Kosho No. 36-19286, Hakama Kosho No. 43-1797, and the like. The organolithium compound used in the production of the prepolymer used in the present invention has one I in the molecule.
Organomo/lithium compounds with bonded J thium atoms are preferred, such as ethyllithium, n-propyllithium, isof.

Lopyllithium, n,-butyllithium, sec-butyllithium, ten-butyllithium, n-bentyllithium, ten-octyllithium, phenyllithium, tolyllithium, butylphenyllithium, cyclohexyllithium, phthylcyclohexyllithium, and the like are used. Particularly common examples include n-butyllithium and sec-butyllithium. or,
In the production of preliminary polymerization, polymerization can be carried out without using any solvent, but in order to allow the reaction to proceed uniformly and prevent local abnormal reactions, one of the lower active hydrocarbons may be used.
Preferably, a mixture of species or more is used as a solvent. The commonly used composition range of monomer and solvent is 5
:95-90:10, preferably 10:90-70:3
It is 0. 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, when using a solvent based on aliphatic hydrocarbons, i.e. containing more than 5% by weight of aliphatic hydrocarbons, more generally more than 7% by weight, the prepolymer vinyl aromatic Preferably, the hydrocarbon content is less than about 75% by weight. 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 or more polymerization vessels connected in series are used, the first polymerization vessel is continuously supplied with the prepolymer, and the first and subsequent polymerization vessels are The remaining monomer is continuously supplied as a monomer mainly composed of a vinyl aromatic hydrocarbon and/or a monomer mainly composed of a conjugated diene, and the remaining monomer is polymerized.
A block copolymer is produced continuously.

In addition, in the present invention, if necessary, monomers mainly composed of vinyl aromatic hydrocarbons and/or are supplied to at least one of the polymerization vessels in the continuous polymerization zone through one or more supply ports attached to the polymerization vessel. Alternatively, the monomers mainly composed of conjugated Geso may be continuously supplied separately for polymerization. It is preferable that the monomers mainly composed of pinyl aromatic hydrocarbons or the monomers mainly composed of conjugated hydrogen supplied to the continuous polymerization zone are weighed in substantially separate polymerization zones, but if necessary, unreacted monomers can be removed. The contained polymeric product can also be fed to the next polymerization vessel or the next polymerization zone to be copolymerized with the newly supplied monomer. Note that polymerizing the monomers supplied to the continuous polymerization zone in substantially separate polymerization zones means that each monomer is polymerized under conditions in which random copolymerization does not occur, preferably at least 5% by weight of each monomer. It is intended that the polymerization be carried out under conditions such that more than 7% by weight of the copolymer, more preferably 7% by weight or more, is not randomly copolymerized. Such conditions may include polymerizing each monomer in separate polymerization vessels, or even in the case of the same polymerization vessel, installing partitions such as perforated plates in the polymerization vessel to prevent uniform mixing of each monomer, or preventing uniform mixing of each monomer. This can be easily set by methods such as sufficiently separating the positions of each mo/mer supply port to prevent uniform mixing, or sufficiently increasing the linear velocity of the contents of the polymerization vessel in the exit direction to prevent reverse mirror combination. I can do it. 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 mode m Two or more polymerization vessels are connected in series, and the first polymerization vessel is continuously supplied with a prepolymer (living polymer), and at the same time, the odd-numbered polymerization vessels are supplied mainly with conjugated gene. (or monomers mainly composed of pinyl aromatic hydrocarbons) are continuously combined and polymerized, and the IJ ping polymer obtained in the odd-numbered polymerization vessels is continuously added to the even-numbered polymerization vessels. At the same time, a monomer mainly composed of vinyl aromatic hydrocarbon (or a monomer mainly composed of conjugated hydrogen) is continuously supplied to the polymerization vessel for polymerization.

Polymerization mode■ In the method of '11, the conjugated gene is further mainly contained in at least one odd-numbered polymerization vessel and/or at least one supply port attached to the side of at least one odd-numbered polymerization vessel. Monomers and/or monomers mainly composed of vinyl aromatic hydrocarbons are continuously fed and polymerized.

Polymerization form '3} One polymerization vessel is used, and the prepolymer, the skiving polymer, and the monomer mainly composed of conjugated genes or the monomer mainly composed of vinyl aromatic hydrocarbons are continuously supplied to the polymerization vessel. Combine and polymerize.

Polymerization mode ■ In the method of '31, a monomer mainly composed of conjugated gene and/or a monomer mainly composed of vinyl aromatic hydrocarbon is continuously supplied from at least one supply port attached to the side of the polymerization vessel. and polymerize.

In the present invention, block copolymers having various block structures can be continuously produced by roughly matching the block structure of the prepolymer, the polymerization vessel in the continuous polymerization zone, and the monomer supply form in the continuous polymerization zone.

Examples of the block structure are as follows. (A-B)nMAkiB-A)nBfA-B)n+,
(Here, A is a polymer block mainly composed of a pinyl aromatic hydrocarbon, and B is a polymer block mainly composed of a conjugated diene. The boundary between the A block and the B block must be clearly distinguished. (N is an integer of 1 or more.) In this specification, polymer block A mainly composed of vinyl aromatic hydrocarbons refers to polymer block A containing vinyl aromatic hydrocarbons in excess of 5% by weight. A polymer block consisting of a copolymer part of a conjugated diene and a vinyl aromatic hydrocarbon and a vinyl aromatic hydrocarbon polymer part, or a polymer block consisting only of a vinyl aromatic hydrocarbon polymer part. It is a combined block.

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 vinyl aromatic hydrocarbon and pinyl 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 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 For the purpose of reducing the viscosity of the solution, 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.
-90:10, preferably 10:90-70:30, more preferably 15:25-50:50. 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 polymerization conditions should be selected 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, precipitates and separates from the polymerization system, accumulates in the polymerization vessel, and lasts for a long time. This is not preferable since continuous polymerization becomes impossible. In the method of the present invention, there is no particular restriction on the average residence time of each polymerization vessel in the continuous polymerization region, but the stability of long-term continuous polymerization operation, productivity, and prevention of deterioration of physical properties of the block copolymer due to loss of living polymer 3 minutes to 5 hours, preferably 5 hours, taking into account
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 set in consideration of productivity, prevention of deactivation of living polymer, etc. Generally, the temperature is 10qo to 180°C, preferably 30 to 140°C, more preferably 50qo to 120°C.
It is operated within the range of 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, care must be taken to prevent impurities such as water, oxygen, carbon dioxide gas, etc. that would inactivate the living polymer from entering the interior of each polymerization vessel. 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 as long as the L/D is 6 or more. In the above-mentioned polymerization mode '1} or '3}, a polymerization vessel in which L/○ is 6 or more, preferably 8 or more, more preferably 10 or more is used to polymerize the monomer mainly composed of vinyl aromatic hydrocarbons. It is preferable to do so.

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. Further, in the method of the above-mentioned polymerization mode (1) or (2), it is preferable to use a polymerization vessel in which L/D is about 8 or more, preferably 10 or more, more preferably 1 hour or more. In this way, a polymerization vessel with a relatively large L/D is recommended when the molecular weight distribution of the polymer blocks formed in each polymerization vessel is made relatively uniform, or when multiple units are supplied to each polymerization vessel. This is to facilitate polymerization operability when monomers supplied via the port are polymerized in substantially separate polymerization regions. The upper limit of L/D is not particularly limited, and even those with extremely large L/D such as a loop type polymerization vessel 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 is no particular restriction on the coagulation device of the polymerization vessel, and a polymerization vessel without a condensation device may be used. However, in general, it is preferable to use a polymerization vessel equipped with a base plate in consideration of uniformity of the polymerization reaction, removal of reaction heat, and prevention of local abnormal reactions. The hawk layer can be of any type, such as a turbine type, screw type, anchor type, or static type. Furthermore, inside the polymerization vessel,
Perforated plates, baffle plates, etc. may be provided as necessary. Next, an embodiment of the present invention will be described based on the flows shown in FIGS. 1 and 2. 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 monomers supplied, etc. are omitted. In FIG. 1, a storage tank T for a prepolymer in a living polymer state and two polymerization vessels R-1 and R-2 are connected in series, and each polymerization vessel is connected to a conjugated gene B and a The vinyl aromatic hydrocarbon B monomer and, if necessary, the solvent S are fed continuously.

The storage tank T stores prepolymerized or Bing polymer (prepolymer), and during continuous polymerization, if necessary, the Bing polymer produced by another polymerization equipment or the Bing polymer is sequentially or continuously stored in the storage tank T. It is also possible to supply The combined reserve army stored in the storage tank T is transferred to the polymerization tank R- through the pipe 1.
1 continuously. The polymer (living polymer) polymerized in the polymerizer R-1 is continuously supplied to the polymerizer R62 through the pipe 3. The block copolymer P polymerized in the polymerization vessel R-2 is continuously taken out from the polymerization vessel R-2 and supplied to the next process, such as the process of adding stabilizers, etc., the process of recovering the solvent, etc. On the other hand, in FIG. 2, conjugated gene B and vinyl aromatic hydrocarbon A monomers and, if necessary, solvent S are continuously supplied through pipes 7 and 10 from the supply port attached to the side of the polymerization vessel in the continuous polymerization region. supplied to

The monomers supplied to the polymerization vessels R-3 and R-4 through the pipes 6 and 9 undergo 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 and 2 illustrate 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, < is 60/40 or less.

If the ratio of the amount of prepolymer supplied to the continuous polymerization zone to the total amount of monomer 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 reduced. It's smaller, which is preferable. In addition, there is no particular restriction on the lower limit of the ratio of the V supply amount of the prepolymer to the total V supply amount of monomers supplied to the continuous polymerization region, but
95 or more, preferably 10/90 or more, more preferably 15/85 or more, in order to improve the controllability of the polymerization operation in the continuous polymerization region of the present invention and the physical properties of the finally obtained block copolymer. Preferred in terms of stability. 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. The vinyl aromatic hydrocarbon content in the monomers fed in the continuous polymerization zone and its feed amount can be adjusted, generally from 5 to 95% by weight, from 10 to 9% by weight, more preferably from 10 to 9% by weight. 1
It is 5 to 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 95% by weight, a thermoplastic resin having excellent transparency and impact resistance can be obtained. Also, the final result. The Mn of the copolymer is 10,000 to 1,000,000, 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 deactivation of the living polymer during continuous polymerization will decrease. 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 determined by adjusting the amount of active ends and monomers of the living polymer supplied to the polymer block forming region and the mixability in the polymerization vessel. However, in order to produce a block copolymer with excellent tensile strength or impact resistance, Mn in the continuous polymerization region is at least 5,000, preferably at least 7,000, more preferably at least 9,00.
0 and Mw/Mn is less than 1.5, preferably 1.3
The following, more preferably 1. At least one vinyl aromatic hydrocarbon polymer block must be formed under the sand. 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 gen and a vinyl aromatic hydrocarbon containing 5% by weight or more of conjugated geso, or a monomer of a conjugated gen alone, and a monomer mainly composed of a vinyl aromatic hydrocarbon is a vinyl aromatic hydrocarbon. A mixture of a conjugated diene and a vinyl aromatic hydrocarbon containing more than 5% by weight of hydrogen, or a monomer of a vinyl aromatic hydrocarbon alone.

Note that in this case, the mixture of conjugated diolefin and vinyl aromatic hydrocarbon does not necessarily require mixing both monomers in advance, but they can be mixed separately as long as the conjugated diolefin and vinyl aromatic hydrocarbon are polymerized under conditions. It may be supplied from the supply port. The conjugated gene used in the present invention is a diolefin having one pair of conjugated double bonds, for example, one
, 3-butadiene, 2-methyl-1,3-butadiene (
isoprene), 2,3-dimethyl, 1,3-butadiene, 1,3-bentadiene, 1,3-hexadiene, etc., and particularly common ones include 1,3-ptadiene and isoprene.

These may be used not only as a single type but also as a mixture of two or more types. The pinyl 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, examples of the solvent include aliphatic hydrocarbons such as butane, bentane, hexane, isobentane, beptane, octane, isooctane, etc., cyclobentane, methylcyclobentane, cyclohexane, methylcyclohexane, ethylcyclohexane, etc. Eight ring hydrocarbons, or aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, etc. can be used.

These can also be mixed and used 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. As the amines, in addition to tertiary amines such as trimethylamine, triethylamine, and tetramethylethylenediamine, cyclic tertiary amines can also be used. 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. In addition, in the method of the present invention, 1,2-butadiene, vinyl acetylene,
Antigelation agents such as cyclobentadiene, primary and secondary amines, butyl chloride, butyl bromide, organic sulfonates, etc. 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, 1SH, 1COO, 1COC1, 1SO3, and 1C at their terminals can be obtained. If necessary, various stabilizers can be added to the block copolymer for the purpose of improving heat resistance, stiffness 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 floc copolymer by precipitation using a precipitating agent such as methanol, and a method of recovering the floc 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 into the solution and distilling off 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 carboxyl 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. , carbon fiber, organic fibers such as synthetic fibers, bears. Adhesives such as linden resin and terbene resin, organic peroxides, inorganic peroxides, crosslinking agents such as sulfur, paraffinic, naphthenic and aromatic oils, various pigments, dyes, fuel agents, antistatic agents, lubricants, plasticizers. It is also possible to use a suitable amount of other fillers or mixtures thereof. The use of the block copolymer obtained by the method of the present invention is extremely wide-ranging, taking advantage of its properties as a thermoplastic elastomer or thermoplastic resin. Examples include rubber thread, hoses, etc. , extruded products such as window frames, sheets, and films; molded products made by thermoforming extruded sheets using vacuum, compressed air, etc.; footwear;
Injection molded products such as containers, blow molded products such as gun tools and household goods, compression molded products such as packing, sheets, plates, etc., as well as various types of packaging such as adhesives as solutions, latex as dispersed in water, and various types of packaging as 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 a continuous polymerization apparatus in which two polymerization vessels were connected as shown in the flow sheet 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 thickener, the interior of which was purged with nitrogen gas. Then n-butyllithium was added and polymerized at 5000 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. The Mw/Mn 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, M
Living polystyrene polymers having w/Mn as shown in Table 1 were prepared. The polymerization vessel used here was then used as a storage tank T in the next continuous polymerization process. In the continuous polymerization process, a polymerization vessel R-1 with a stainless steel boat with an L/D of approximately 12 is used,
A polymerization vessel with L/D of about 8 was used as R-2.

The living polymer of polystyrene and butadiene were placed in the polymerization vessel R-1, which had been internally purged with nitrogen gas and heated to a predetermined temperature, and the styrene was placed in the polymerization vessel R-2 at a weight ratio of 15:70. :V was continuously supplied at a ratio of 15:1. Butadiene and styrene are each 2% by weight
Supplied as a cyclohexane solution. The average residence time in polymerization vessel R-1 and polymerization vessel R-2 was about 45 minutes and about 35 minutes, respectively, and the polymerization temperature was about 90°C on average, respectively.
, and about 75° C. for continuous polymerization. Under these conditions, the conversion rate of putadiene or styrene at the outlet of each polymerization vessel was about 95% or more. 0.5 parts by weight of each of di-ten-butyl-p-cresol and trisnonylphenyl phosphorite were added as stabilizers to the block copolymer solution continuously fed from the polymerization vessel R-2 per 10 parts by weight of the block copolymer. Thereafter, the solvent was removed by heating to obtain a block copolymer.

The styrene content of the obtained block copolymer is about 29~
31% by weight, bu. The styrene content is approximately 28-31% by weight, and the melt o-index (ASTMD-123
8-5, 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 addition, in the continuous polymerization according to the method of the present invention, a block copolymer exhibiting almost desired physical property values is produced at a relatively early stage when the polymerized block copolymer solution starts to come out from the exit of the polymerization vessel R-2. After about 30 minutes, a steady state was reached, and thereafter a block copolymer having the physical properties shown in Table 1 was 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 JIS K-6301.

Examples 4 and 5 and Comparative Example 3 Using IJ Bing polymer, a block copolymer consisting of (polybutadiene)-(polystyrene), obtained in an n'-hexane solution 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 a block copolymer sliding polymer, 20% by weight of butadiene, which had been purified and dried in advance, was placed in a stainless steel polymerization vessel with a nitrogen gas purging inside.
A n-hexane solution containing a concentration of
Polymerized for minutes.

Thereafter, an n-hexane solution containing styrene at a concentration of 2% by weight was added, and the polymerization was continued at 50 qo for 2 hours.
The amount of monomer and catalyst added is polystyrene block copolymer. The molecular weight and styrene content of the
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. Continuous polymerization was carried out in the same manner as in Example 1, except that the monomers, ptagene and styrene, were supplied as 2% by weight n-hexane solutions, and the monomer supply ratios to each polymerization vessel were as shown in Table 2. . The finally obtained block copolymer has a styrene content of approximately 39 to 41% by weight, a block styrene content of approximately 38 to 41% by weight, and a melt flow index of 8 to 41% by weight.
It was 12. In addition, as comparative example 3, the styrene content was 3
Continuous polymerization was carried out in the same manner as above using IJ Bing polymer, which is a random copolymer with a styrene content of 31 wt%, instead of IJ Bing polymer, which is a block copolymer containing 1 wt%, but the vulcanized state was A block copolymer with excellent tensile strength could not be obtained.

Table 2 Example 6 and Comparative Example 4 A living polymer of polystyrene obtained from the bottom of a stainless steel polymerization vessel with an L/D of about 20 in the same manner as in Example 1, and butadiene in an amount of 2% by weight A cyclohexane solution containing styrene at a concentration of 2 wt. and polymerized.

The living polymer, butadiene, and styrene were each continuously fed at a weight ratio of 20:60:20 so that the average residence time in the polymerization vessel was about 30 minutes. The polymerization temperature was set at an average of about 90 qo from the bottom of the polymerization vessel to the styrene supply port, and about 80 qo on average from the styrene supply port to the top of the polymerization vessel. Furthermore, in Example 6, ptagene supplied from the bottom of the polymerization vessel and styrene supplied from the side of the polymerization vessel were polymerized in separate polymerization regions, and the molecular weight distribution of each polymer block was narrowed. For the purpose, three perforated plates with an open area ratio of about 30% were provided at equal intervals in the polymerization vessel, but in Comparative Example 4, no perforated plates were used. The styrene content of the finally obtained block copolymer is about 39-41% by weight, the block styrene content is about 35-4% by weight in the case of Example 6, and about 25-3% by weight in the case of Example 4. %Met.

The tensile strength of the flock copolymer of Example 6 was much better. The present inventors believe that the reason why the tensile strength of the block copolymer of Comparative Example 4 is lower than that of Example 6 is due to the large molecular weight of the polystyrene blocks formed in the continuous polymerization process, and therefore Continuous polymerization was attempted under the same conditions as in Example 6 and Comparative Example 4 using a polybutadiene living polymer having the same active site concentration. After each of the obtained block copolymers was decomposed with a peroxide, the molecular weight of the polystyrene portion of the polystyrene was measured, and the Mn of the polystyrene corresponding to Comparative Example 4 was approximately 4,500. Comparative Example 5 In Example 1, the polymerization vessel with L/D of about 2 was used as R-2, and the prepolymer applied to the polymerization vessel R-1, the IJ polymer, butadiene, and the polymerization vessel R-2 were supplied. A block with a styrene content of approximately 39 to 41% by weight was prepared in the same manner as in Example 1, except that the amount of styrene was continuously supplied at a weight ratio of 20:60:20. A block copolymer having a styrene content of about 38-41% by weight and a melt flow index of 8-12 was obtained.

The physical properties of this block copolymer were as shown in Table 3. The present inventors believed that the cause of the inferior tensile strength of the block copolymer of Comparative Example 5 was due to the polystyrene flocs formed in the continuous polymerization process, and attempted the same analysis as in Example 6. As a result, it was revealed that the polystyrene block formed in the continuous polymerization region had a Mw/Mn of 1.5 or more, and therefore had a low tensile strength. 3 Table Examples 7 and 8 In place of the polystyrene living polymer used in Example 6, a living block copolymer produced in the same manner as the block copolymer used in Example 4 was used. Continuous polymerization was carried out in the same polymerization mode as in Example 6.

The polymerization conditions are shown in Table 4. Incidentally, butylene and styrene supplied to the polymerization vessel each have a concentration of 2% by weight n
- A hexane solution was used, and the average residence time in the polymerization vessel was approximately 3 minutes. Table 4 Note 2) The tensile properties of Example 8 were measured according to JIS-K6871.

Examples 9, 10 and 11 Block copolymers having a styrene content of 6% by weight or more were continuously polymerized in the same polymerization form as in Examples 1, 4 and 6.

The results are shown in Table 6. Table 6 Note 3) The physical properties of the above examples were measured according to JIS-K-6871K.

Example 12 A self-cleaning polymerization vessel with an L/D of about 30 and equipped with two screw-type rope layers was used as the polymerization vessel for the continuous polymerization process, and the monomer added in the continuous polymerization process was not diluted with a solvent. Continuous solvent-free polymerization was carried out.

A living polymer of polystyrene, butadiene, and a portion of styrene polymerized in the same manner as in Example 1 except that a cyclohexane solution containing styrene at a concentration of 5% by weight was used in a self-cleaning polymerization vessel. From the bottom of the polymerization vessel, the remainder of the styrene was further added from the supply ports provided at about 3/3 degrees from the bottom of the polymerization vessel at a ratio of 30:20:15:35 by weight, respectively, to the average retention in the polymerization vessel. It was fed continuously for about 2 minutes.

The polymerization temperature is about 800C on average from the bottom of the polymerization vessel to the styrene supply port in the middle, and about 110qo on average thereafter.
It was set to The finally obtained floc copolymer having a styrene content of 8% by weight exhibited almost the same physical properties as the block copolymer of Example 11.

[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. T...Storage tank, R-1,
R-2, R-3, R-4...Polymerizer, 1 to 10
...Piping, B... Conjugated Jen, A...
Vinyl aromatic hydrocarbon, S...solvent, P...block copolymer. Figure 1 Figure 2

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 continuously producing a copolymer, (a
) Using a part of the monomers forming the block copolymer in advance and using an organolithium compound as a catalyst, 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 vinyl aromatic hydrocarbon polymer block is produced by a batch method,
(b) After that, in the continuous polymerization region where the remaining monomers are continuously polymerized, one or more L/Ds (
L is the length of the polymerization vessel, and D is the inner diameter of the polymerization vessel. The remaining monomer is continuously fed into the polymerization vessel as a monomer mainly composed of vinyl aromatic hydrocarbons and/or a monomer mainly composed of conjugated dienes, so that the number average molecular weight is at least 5,000 and the number average molecular weight is equal to the number average molecular weight. 1. A method for continuously producing a block copolymer, which comprises carrying out continuous polymerization under conditions such that at least one vinyl aromatic hydrocarbon polymer block having a molecular weight ratio of less than 1.5 is formed. 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. Claim 1, wherein the prepolymer is a living block copolymer having a vinyl aromatic hydrocarbon content of about 75% by weight or less, produced in a solvent mainly composed of aliphatic hydrocarbons. Method described. 7 In the continuous polymerization region, a monomer mainly consisting of conjugated diene is continuously supplied and polymerized to the odd-numbered polymerization vessel of two or more polymerization vessels connected in series, and the monomer obtained in the odd-numbered polymerization vessel 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 prepolymer is a vinyl aromatic hydrocarbon polymer, or 1
A living polymer, which is a block copolymer consisting of a polymer block mainly composed of two conjugated dienes and a polymer block mainly composed of a vinyl aromatic hydrocarbon, is continuously supplied to the first polymerization vessel. At the same time, monomers mainly composed of conjugated dienes are continuously supplied to the first polymerization vessel for polymerization, and the living polymer obtained in the first polymerization vessel is transferred to the second polymerization vessel. 8. The method according to claim 7, wherein the monomer mainly composed of vinyl aromatic hydrocarbons is continuously supplied to the second polymerization reactor for polymerization. 9 A patent claim in which monomers mainly composed of vinyl aromatic hydrocarbons and/or monomers mainly composed of conjugated dienes are supplied to at least one polymerization vessel separately from two or more supply ports for polymerization in a continuous weight range. The method described in item 1. 10 One polymerization vessel is used in the continuous polymerization region, and a monomer mainly consisting of conjugated diene is continuously supplied from the bottom of the polymerization vessel, and at the same time, from at least one supply port provided on the side of the polymerization vessel. Claim 9: Continuously supplying a monomer mainly composed of vinyl aromatic hydrocarbons
The method described in section. 11 The prepolymer is a vinyl aromatic hydrocarbon polymer or a block copolymer consisting of a polymer block mainly composed of one conjugated diene and a polymer block mainly composed of one vinyl aromatic hydrocarbon. If a living polymer is continuously supplied from the bottom of one polymerization vessel, and a monomer mainly composed of conjugated diene is continuously supplied to the polymerization vessel from the bottom, at the same time at least 11. The method according to claim 10, wherein the monomer mainly consisting of vinyl aromatic hydrocarbon is continuously fed through one feed port for polymerization. 12 Claim No. 1 in which a polymerization vessel with an L/D of about 8 or more is used as a polymerization vessel to which monomers mainly composed of vinyl aromatic hydrocarbons and monomers mainly composed of conjugated dienes are supplied from two or more supply ports. The method according to item 9, item 10 or item 11. 13 When a solvent mainly composed of aliphatic hydrocarbons is used as the polymerization solvent in the continuous polymerization region, the vinyl aromatic hydrocarbon content of the polymer formed in each polymerization vessel is approximately 75% by weight. The method described in Scope 1. 14 The ratio of the amount of monomers forming the prepolymer to the amount of monomers continuously polymerizing in the continuous polymerization region is 5:95 to
The method according to claim 1, wherein the ratio is 90:10 (weight ratio). 15. 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%. 16 The vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is 5% by weight or more, 60
16. The method of claim 15, wherein less than % by weight. 17 The vinyl aromatic hydrocarbon content in the block copolymer finally obtained by continuous polymerization is 60 to 95% by weight
16. The method according to claim 15.