JPS6017409B2 - Method for producing block copolymer mixture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel block copolymer mixture consisting of a conjugated diene and a vinyl aromatic hydrocarbon, and more specifically, to a method for producing a novel block copolymer mixture comprising a conjugated diene and a vinyl aromatic hydrocarbon. The present invention relates to a method for producing a novel block copolymer mixture having a composition distribution such that the vinyl aromatic hydrocarbon content of the present invention changes (increases and/or decreases) substantially continuously with increasing molecular weight.

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.

In addition, if the vinyl aromatic hydrocarbon content is relatively high,
Since thermoplastic resins can be obtained that are transparent and have excellent impact resistance, their usage has increased in recent years, mainly in the field of food packaging containers, and at the same time, their applications are diversifying. However, as the uses become more diverse, a problem arises in that a single block copolymer alone cannot sufficiently satisfy the various properties required for various uses, and a solution to this problem is desperately needed. Recently, in order to meet this demand, a method has been proposed in which block copolymers having different compositions are used together.

For example, Japanese Patent Application Laid-open No. 52-27447 and Japanese Patent Publication No. 53-235 disclose a method of using two types of block copolymers with different vinyl aromatic content in combination for sealing materials and pressure-sensitive adhesive tapes. It has been disclosed that improved effects that cannot be achieved with a single block copolymer alone have been obtained. Moreover, in Japanese Patent Application Laid-Open No. 54-62251, polystyrene contains 2
A method of obtaining an impact-resistant resin with good transparency by using various block copolymers in combination is disclosed. however,
The block copolymers used in these methods have completely different vinyl aromatic hydrocarbon contents, so the interaction between them is small and the synergistic effect is not sufficiently exhibited. In addition, in the above method, after the desired block copolymer is produced in advance, it is necessary to mix them in the desired ratio, which requires an extremely complicated operation.In view of the current situation, the present inventors The present invention was achieved through extensive research into a block copolymer mixture with a large interaction effect and an efficient method for producing the same.

That is, according to the present invention, at least two vinyl aromatic hydrocarbon-based polymer blocks and at least one
In a mixture of a block copolymer having a polymer block mainly composed of conjugated genes, the vinyl aromatic hydrocarbon content of the block copolymer constituting the block polymer mixture increases substantially as the molecular weight increases. A novel method for producing a block copolymer mixture characterized by having a composition distribution that continuously changes (increases and/or decreases) is provided.

The block copolymer mixture obtained by the method of the present invention has a molecular weight distribution with a substantially single peak (monomodal) as a whole.
Although the molecular weight distribution is The interaction is large, and an extremely efficient synergistic effect can be expressed.

For example, an adhesive containing a block copolymer mixture obtained by the method of the present invention has contradictory adhesive properties such as tack (
It has excellent both adhesion and creep properties, and when blended with polystyrene, a composition with a good balance of transparency and impact resistance can be obtained. Moreover, the block copolymer polymer obtained by the method of the present invention has excellent processability compared to conventional mixtures. For example, a block copolymer having a vinyl aromatic hydrocarbon content of 60 to 9% by weight is
Injection molding produces molded products with less anisotropy.
It has the characteristics of producing sheets, films, etc. with less uneven thickness in sheet molding, inflation extrusion molding, etc. In this respect, the block copolymer mixture obtained by the method of the present invention is completely different from conventional block copolymer mixtures. Furthermore, although the block copolymer polymer obtained by the method of the present invention is a mixture of block copolymers having different vinyl aromatic hydrocarbon contents and molecular weights, it has poor mechanical properties such as tensile strength and impact resistance. It has the characteristic of being excellent in quality.

Furthermore, conventional block copolymer mixtures are produced by a method in which a desired block copolymer is produced in advance and then two or more of them are mixed in a desired ratio, which requires extremely complicated operations. According to the method of the present invention, a mixture of block copolymers with different vinyl aromatic contents, that is, a block copolymer mixture with a non-uniform composition distribution, can be easily produced in one step and by continuous polymerization, and can be produced with extremely high precision. This can be said to be a temporary method.

In addition, the method of the present invention has the following advantages: 1) The permissible range of residence time in each polymerization vessel is large, and the production volume is highly variable; 2) The time to reach a steady state is short, and losses in the initial stage of polymerization are small. It has the characteristics that continuous polymerization for a long time is possible without producing a 3' gel-like polymer. The present invention will be explained in detail below.

Although the block copolymer mixture obtained by the method of the present invention shows a substantially single peak (monomodal) molecular weight distribution as a whole, the vinyl aromatic It has a very unique compositional distribution in which the hydrocarbon content increases and/or decreases virtually continuously with increasing molecular weight.

In this specification, the vinyl aromatic hydrocarbon content substantially continuously increases and/or decreases with increasing molecular weight means that the vinyl aromatic hydrocarbon content increases and/or decreases substantially continuously with increasing molecular weight. means that there are no substantial discontinuities in the change in group hydrocarbon content, even if the vinyl aromatic hydrocarbon content increases or decreases monotonically or continuously with increasing molecular weight. Alternatively, it may change while decreasing repeatedly. Generally, block copolymer mixtures in which the vinyl aromatic hydrocarbon content increases or decreases substantially monotonically with increasing molecular weight are preferred. Also, the fact that the overall molecular weight distribution of the block copolymer polymer shows a substantially single peak (monomodal) molecular weight distribution means that the molecular weight distribution is measured using an analytical method such as gel permeation chromatography (GPC). This means that there are no two or more distinct peaks between the block copolymers that make up the main component in the floc copolymer, and the block copolymer does not have a peak around one peak. One or more types of components may be mixed as so-called peak shoulders. The block copolymer polymer obtained by the method of the present invention consists of block copolymers in which at least one polymer block of the block copolymers constituting the polymer block has a different molecular weight. The polymer blocks with mutually different molecular weights in the block copolymer may be either polymer blocks mainly composed of vinyl aromatic hydrocarbons or polymer blocks mainly composed of conjugated genes, but generally, the polymer blocks mainly consist of conjugated genes. A mixture of block copolymers in which at least one polymer block is mutually changed is preferred. A more preferred mixture is
A polymer block having at least one vinyl aromatic hydrocarbon polymer block having 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, and which is mainly composed of conjugated diene. It is a mixture composed of a block copolymer, at least one of which has polymer blocks having mutually different molecular weights. The block copolymer polymer obtained by the method of the present invention has a vinyl aromatic hydrocarbon content of a component with a low vinyl aromatic hydrocarbon content and a component with a high vinyl aromatic hydrocarbon content among the floc copolymers that are the main components in the block copolymer mixture. It is a mixture having compositional heterogeneity in which the difference in hydrocarbon content is 5% by weight or more, preferably 10% by weight or more, more preferably 15% by weight or more.

Here, the block copolymer that is the main component in the floc copolymer mixture refers to the block copolymer that remains after removing a portion of the low molecular weight component and high molecular weight component contained in the mixture. However, to give a numerical example,
It is the remaining component after removing the low molecular weight component and the high molecular weight component by 5% by weight (ratio to the entire block copolymer mixture), preferably 10% by weight, and more preferably 15% by weight. Methods for understanding the composition distribution of a floc copolymer mixture include a method in which a block copolymer mixture is subjected to molecular weight fractionation according to a conventional method, and the molecular weight and vinyl aromatic hydrocarbon content of each fraction obtained are measured, or GPC. Although there is a method of simultaneously measuring the molecular weight distribution and the composition distribution, the method of grasping the composition distribution of the block copolymer of the present invention is not limited to these methods. The vinyl aromatic hydrocarbon content of the block copolymer mixture obtained by the method of the present invention is generally 5 to 95% by weight, preferably 10 to 9% by weight, and more preferably 15 to 85% by weight.
It is.

If the vinyl aromatic hydrocarbon content in the block copolymer is 5% by weight or more and less than 6% by weight, preferably less than 55% by weight, it will be a thermoplastic with excellent tensile strength and elasticity in an unvulcanized state. A mixture in the form of an elastic body is obtained, and when the amount is 60 to 95% by weight, preferably 60 to 85% by weight, a mixture in the form of a thermoplastic resin with excellent transparency and impact resistance is obtained. The content of vinyl aromatic hydrocarbon polymer blocks contained in the block copolymer polymer obtained by the method of the present invention is generally 40% or more, preferably 50% or more, at a block rate expressed by the following formula, More preferably, it is 70% or more. Flock rate (%) = (weight of pinyl aromatic hydrocarbon polymer block in the floc copolymer polymer) X.

(Weight of total vinyl aromatic hydrocarbons in the block copolymer mixture) A block copolymer mixture with a high flocculation ratio has excellent tensile strength and hardness. In addition, the number average molecular weight of the floc copolymer polymer finally obtained is 10,00~1
,000,000, preferably 30,000-500,
It is 000. If it is smaller than this range, the mechanical strength of the flock copolymer polymer, such as tensile strength, impact resistance, etc. will decrease, and if it is larger than this range, the processability and dispersibility when blending with other components will be reduced. Undesirable because it is inferior. The block copolymer compound described above can be produced as follows.

That is, in an inert hydrocarbon solvent, using an organolithium compound as a catalyst, a vinyl aroma having 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. A living polymer having at least one group hydrocarbon polymer block (hereinafter referred to as a prepolymer) is produced in advance by a batch method, {b} and then one or more polymerization vessels connected in series are used. In the continuous polymerization zone, the prepolymer is continuously supplied to the first polymerization vessel, and at the same time, the first or subsequent polymerization vessels are supplied with monomers mainly containing vinyl aromatic hydrocarbons or conjugated polymers mainly containing vinyl aromatic hydrocarbons. Continuous polymerization is carried out by continuously supplying a monomer containing a vinyl aromatic hydrocarbon, or a monomer containing a vinyl aromatic hydrocarbon and a monomer containing a conjugated hydrogen are polymerized so that each monomer is polymerized in substantially separate polymerization regions. At least one of the produced polymer blocks is supplied separately and continuously for continuous polymerization, and the L/D of at least one of the polymerization vessels used in the continuous polymerization zone is less than 6.
It is produced by widening the molecular weight distribution of individual polymer blocks.

The method of the present invention is characterized in that the number average molecular weight (hereinafter abbreviated as Mn) is at least 5,000, preferably at least 7,000, which is produced using an organolithium compound as a catalyst.
More 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, and even more preferably 1. The purpose of this invention is to use a prepolymer (living polymer) having at least one vinyl aromatic hydrocarbon polymer block as a catalyst in a continuous polymerization process.

If Mn and Mw/Mn of the pinyl 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 finally obtained block copolymer Otherwise, it is not preferable because the impact resistance decreases. Mn and Mw/Mn of Ap are determined as is when the prepolymerization is polystyrene, or after decomposition of the prepolymer with peroxide (L・M
・Kolthoff et al, J. Polymer
Scj. , 1, 429 (1946)) collected Ap component, or A obtained by polymerizing under the same conditions as the polymerization conditions of Ap.
It can be determined directly or indirectly by measuring p-polymer etc. by gel permeation chromatography.

The vinyl aromatic hydrocarbon content in the prepolymer is at least 40% by weight, preferably at least 5% by weight, more preferably at least 6% by weight.
% by weight is recommended in order to obtain a block copolymer with excellent tensile strength.

In the present invention, the polymer horizontal structure of the prepolymer is not particularly limited, but the following may be cited as a model example. Ap-Lj, (Ap-BpchinLi,
(Bp-ApchinLiApfBp-ApchinLiBp÷
Ap-Bp→nLi (where Bp indicates a conjugated gene polymer block and/or a random polymer block of a conjugated gene and a 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 preferred as the prepolymer used in the method of the invention are homopolymers of vinyl aromatic hydrocarbons or living polymers having the structure Bp-Ap-Li.

The molecular weight of the prepolymer used in the present invention is a number average molecular weight of 5,000 to 300,000, preferably 7,000 to 300,000.
100,000 more preferably 9,000 to 50,000
It is 0.

As the method for producing the prepolymer, a polymerization method consisting of batch polymerization, semi-batch polymerization, or a combination thereof that yields a prepolymer with a uniform molecular weight distribution can be adopted, and a specific polymerization method is described in Japanese Patent Publication No. 36-19286. Ya, special public service 1977-
Examples include the method described in Publication No. 1797y. The organolithium compound used in the production of the prepolymer used in the present invention is a hydrocarbon having at least one IJ tium atom bonded in the molecule, such as n-propyllithium, isopropyllithium, n-butyllithium, s
ec-butyllithium, trt-butyllithium, n-
Benzyllithium, lithium toluene, benzyllithium, 1,4 dilithio-n-butane, 1,2 dilithio-1,
Examples include 2-diphenylethane, trimethylene dilithium, oligoisoprenyl dilithium, etc., but a preferred organic lithium compound is an organic monolithium compound in which one IJ tium atom is bonded in the molecule.

Particularly preferred are n-butyllithium, Sec-
Examples include butyllithium. In addition, 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 type of inert hydrocarbon may be used. It is preferable to use a mixture of these or more as a solvent. The commonly used composition range of monomer and solvent is 5:95 to 90:
10, preferably 10:90 to 70:30. As for 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, that is, a solvent containing more than 5% by weight, more generally more than 70% by weight, of aliphatic hydrocarbons, the vinyl aromatic carbonization of the prepolymer is necessary. Preferably, the hydrogen 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 polymerization vessel or two or more polymerization vessels connected in series are used, the first polymerization vessel is continuously supplied with the above-mentioned preliminary polymerization vessel, and the first or After that, monomers mainly composed of vinyl aromatic hydrocarbons or monomers mainly composed of conjugated hydrogen are continuously supplied to the polymerization vessel for continuous polymerization, or monomers mainly composed of vinyl aromatic hydrocarbons and conjugated hydrogen are continuously supplied. A block copolymer mixture is continuously produced by continuously supplying and continuously polymerizing monomers mainly consisting of the following monomers so that each monomer is polymerized in substantially separate polymerization regions.

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 diene can be separately and continuously supplied for polymerization. It is preferable that the monomer mainly composed of pinyl 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 polymerized in separate polymerization zones. It is also possible to supply the polymer mixture containing the monomer to the next polymerization vessel or the next polymerization zone and copolymerize it with the newly supplied monomer. It should be noted that the monomers supplied to the continuous polymerization zone are polymerized in substantially separate polymerization zones under conditions where the respective monomers are not randomly copolymerized, preferably at least 5% by weight of each monomer. means that the polymerization is carried out under conditions where 7% by weight or more is not randomly copolymerized. Such conditions include polymerizing each monomer in separate polymerization vessels, or even in the case of the same polymerization vessel, installing a partition wall such as a plate in the polymerization vessel to prevent uniform mixing of each monomer, or polymerizing each monomer in separate polymerization vessels. - Easily set by methods such as sufficiently separating the positions of each monomer supply port to prevent uniform mixing of the monomers, or sufficiently increasing the linear velocity of the contents of the polymerization vessel in the exit direction to prevent back mixing. I can do it. The block copolymer mixture can be prepared by broadening the molecular weight distribution of at least one polymer block in the formation of polymer blocks in continuous polymerization zones.

The molecular weight distribution of a polymer block can be easily widened by adjusting the miscibility in the forming region of the polymer block by adjusting the shape of the polymerization vessel (for example, L/D ratio), clarification conditions, and the like. When forming a polymer floc with a wide molecular weight distribution, its M'w/M'n (where M'w and M'n are the Mw and Mn of the polymer block, respectively)
) is generally 1.3 or more, preferably 1.4 or more,
More preferably, it is 1.6 or more. The polymer block that widens the molecular weight distribution may be either a polymer block mainly composed of vinyl aromatic hydrocarbons or a polymer block mainly composed of conjugated hydrogen, but at least one of the former has Mw
/Mn is less than 1.5, preferably 1.3 or less, more preferably 1. Maintain it so that it is below the peak, and the latter's Mw no M
It is preferable to widen n in order to obtain a block copolymer having excellent tensile strength or impact resistance. 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 '1' Two or more polymerization vessels are connected in series, and the first polymerization vessel is continuously supplied with prepolymer and skiving polymer, while the odd-numbered polymerization vessel is supplied mainly with conjugated gene. A monomer (or a monomer mainly composed of pinyl aromatic hydrocarbons) is continuously supplied and polymerized, and the polymer obtained in the odd-numbered polymerization vessels is continuously transferred to the even-numbered polymerization vessels. At the same time, a monomer mainly composed of vinyl aromatic hydrocarbons (or a monomer mainly composed of conjugated diene) is continuously supplied to the polymerization vessel for polymerization.

Polymerization mode ■ In the method of '1', at least one odd-numbered polymerization vessel and/or at least one even-numbered polymerization vessel and/or at least one attached to the side of at least one even-numbered polymerization vessel From one supply port, a monomer mainly composed of conjugated diene and/or a monomer mainly composed of vinyl aromatic hydrocarbon is continuously supplied for polymerization.

Polymerization mode (1 piece of 3' is used in a polymerization vessel, and a prepolymer, a sliding polymer, and a monomer mainly composed of conjugated genes or a monomer mainly composed of vinyl aromatic hydrocarbons are continuously supplied to the polymerization vessel. Polymerize.

Polymerization form {4} In the method of {3', at least one V supply port attached to the side of the polymerization vessel further supplies a monomer mainly composed of conjugated Geso and/or a monomer mainly composed of pinyl aromatic hydrocarbon. is continuously supplied in V for polymerization.

In the method of the present invention, the block structure of reserve army combination,
The number of polymerizers in the continuous polymerization region and the number of polymerizers in the continuous polymerization region
Block copolymer polymers composed of block copolymers having various block structures can be continuously produced by combining the polymer-containing structures.

Examples of the block structure are as follows. (A-B)nMA-B-A)nB-A-B)n+,
(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, polymer block A mainly composed of pinyl aromatic hydrocarbons refers to a polymer block A containing pinyl aromatic hydrocarbons as a main component.
% by weight, and is composed of a copolymer part of a conjugated diene and a vinyl aromatic hydrocarbon and a vinyl aromatic hydrocarbon polymer part, or a vinyl aromatic hydrocarbon polymer It is a polymer block composed only of parts.

Moreover, the polymer block B mainly composed of conjugated gene is a polymer block in which the content of conjugated gene is 5% by weight or more, and the copolymer part of conjugated gene and vinyl aromatic hydrocarbon and the conjugated gene polymer are A polymer block composed of a combined portion, a polymer block composed of a copolymer portion of a conjugated diene and a vinyl aromatic hydrocarbon, or a polymer block composed only of a conjugated diene 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 method of the present invention, the ratio of the amount of monomers forming the prepolymer fed to the continuous polymerization zone to the total amount of monomers added to the continuous polymerization zone is 90'10 or less, preferably 8
It is 0'20 or less, more preferably 60/40 or less.

The ratio of the supply amount of reserve army coalescence supplied to the continuous polymerization region to the total supply amount of monomers supplied to the continuous polymerization region is 90/10.
Exceeding this is not preferable because the proportion of polymerization in the continuous polymerization region decreases, and the productivity improvement effect of continuous polymerization decreases. In addition, there is no particular restriction on the lower limit of the ratio of the amount of prepolymer supplied to the continuous polymerization zone to the total amount of monomer supplied to the continuous polymerization zone, but 5'95
or more, preferably 10'90 or more, more preferably 15
/85 or more is preferred from the viewpoint of controllability of polymerization operation in the continuous polymerization region of the present invention and stability of physical properties of the block copolymer polymer finally obtained. In the method of the present invention, the vinyl aromatic hydrocarbon content as a whole of the block copolymer polymer finally obtained by continuous polymerization is determined by the vinyl aromatic hydrocarbon content in the prepolymer and its continuous polymerization area. It can be adjusted by adjusting the amount of the monomer added to the monomer, the content of vinyl aromatic hydrocarbon in the monomer added in the continuous polymerization region, and the amount of the vinyl aromatic hydrocarbon fed.

In addition, the molecular weight of each polymer block formed in the continuous polymerization region can be determined by adjusting the amount of active terminals and monomers of the living polymer fed into the polymer block forming region and the incorporation in the polymerization vessel. However, Mn is at least 500Q, preferably at least 7,000, more preferably at least 9,000, and Mw/Mn is 1.
less than 5, preferably 1.3 or less, more preferably 1.2
It is preferable to form at least one vinyl aromatic hydrocarbon polymer block below in order to produce a block copolymer with excellent tensile strength or impact resistance. 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~
The ratio of 90:1 is 10:90 to 70:30, more preferably 15:85 to 50:60. 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 that requires less energy for removing the solvent. However, when using a solvent mainly composed of aliphatic hydrocarbons, it should be noted that the content of vinyl aromatic hydrocarbons during polymerization in the continuous polymerization region is not more than about 75% by weight, preferably not more than 7% by weight. The key is to select polymerization conditions so that 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, the average residence time of each polymerization vessel in the continuous polymerization zone is not particularly limited;
Taking into consideration 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, the polymerization time is 3 minutes to 5 hours, preferably 5 minutes to 3 hours, and more preferably one polymerization period. One to two hours is preferred.

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 1000 to 18000, preferably 30q○ to 14000, more preferably 50°C to
Operated in the 120oC range. 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 temperature 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 tower-type polymerization vessel, a tower-type polymerization vessel, a tube-type polymerization vessel, etc., and is not particularly limited. At least one polymerization vessel in which L/D is less than 6, preferably 1 or more and 5 or less in the continuous polymerization region must be used.

Here, upper 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. As mentioned above, in the method of the present invention, at least one polymerization vessel with L/D of less than 6, preferably 1 to 5 must be used.

Regarding other polymerization vessels, it is preferable to use a polymerization vessel with a relatively large L/D. 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 to be made relatively uniform, or when polymer blocks are supplied to each polymerization vessel from multiple supply ports. This is because polymerization operability becomes easier when the monomers are polymerized in substantially separate polymerization regions. For example, a polymerization vessel for polymerizing monomers mainly composed of vinyl aromatic hydrocarbons in the above-mentioned polymerization mode {1} or glue has a L/D of about 6 or more, preferably 8 or more, and more preferably 10 or more. It is preferable to use
In addition, in the method of the above-mentioned polymerization form [2} or (2), L
It is preferable to use a polymerization vessel in which /D is about 8 or more, preferably 10 or more, more preferably 1 or more. There are no particular restrictions on the bottom layer of the polymerization vessel, and a polymerization vessel without a pine layer may be used. However, in general, it is preferable to use a polymerization vessel equipped with a cylindrical shell, taking into consideration the uniformity of the polymerization reaction, the removal of reaction heat, and the prevention of local abnormal reactions. Any type of fly azusa device can be used, such as a turbine type, screw type, anchor type, or static type. Furthermore, a perforated plate, a baffle plate, etc. may be provided in the polymerization vessel 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 prepolymer IJ Bing polymer and polymerizers R-1 and R-
2 are connected in series, and each polymerization vessel is continuously supplied with conjugated gene B and/or vinyl aromatic hydrocarbon A monomer and, if necessary, solvent S through pipes 2 and 4, respectively.

A prepolymer (living polymer) that has been polymerized in advance is stored in the storage tank T, and during continuous polymerization, if necessary, the living polymer produced by another polymerization equipment or the living polymer can be sequentially or continuously stored in the storage tank T. It is also possible to supply The prepolymer stored in storage tank T is transferred to polymerizer R- through pipe 1.
1 continuously. The polymer (living polymer) polymerized in the polymerizer R-1 is continuously supplied to the polymerizer R-2 through a pipe 3. The block polymer mixture P polymerized in the polymerization vessel R-2 is continuously taken out from the polymerization vessel R-2 and is supplied to the next process, such as the addition process of a stabilizer, etc., the solvent recovery process, etc. On the other hand, in FIG. 2, the monomer and/or A and, if necessary, the solvent S are supplied from the supply port attached to the side of the polymerization vessel in the continuous polymerization region.
is continuously supplied through pipes 7 and 10.

The monomers supplied to polymerizers R-3 and R-4 through pipes 6 and 9 undergo substantial reaction in the region between the bottom and side supply ports of each polymerizer, and are also supplied through pipes 7 and 10. The supplied monomer is controlled so that substantial reaction proceeds in the region between the side supply port and the top of the polymerization reactor. It should be noted that FIGS. 1 and 2 are for explaining embodiments of the present invention more specifically, and it goes without saying that the scope of the present invention is not limited thereto.

Next, the monomers, solvents, etc. used in the method of the present invention will be explained.

In the present invention, the monomer mainly consisting of conjugated genes is
A mixture of conjugated diene and vinyl aromatic hydrocarbon containing 50% by weight or more of conjugated diene, or a monomer containing only conjugated diene, and a monomer mainly composed of vinyl aromatic hydrocarbon is defined as A mixture of a conjugated diene and a vinyl aromatic hydrocarbon, or a monomer of vinyl aromatic hydrocarbon alone, containing more than .

It should be noted that the mixture of conjugated diolefin and vinyl aromatic hydrocarbon does not necessarily require pre-mixing of both monomers, as long as the conjugated diolefin and vinyl aromatic hydrocarbon are copolymerized. The V supply may be supplied from separate V supply ports. The conjugated genes used in the present invention include:
A diolefin having one pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3 pentadiene, 1,3 hexadiene. Among them, particularly common ones include 1,3-butadiene and isoprene.

These may be used not only as a single type but also as a mixture of two or more types. Vinyl aromatic hydrocarbons used in the present invention include styrene, methylstyrene, ethylstyrene,
Among p-te 9-butylstyrene, dimethylstyrene, Q-methylstyrene, vinylnaphthalene/vinylanthracene, etc., styrene and Q-methylstyrene are particularly common.

These may be used not only as a single type but also as a mixture of two or more types. When a solvent is used in the method of the present invention, the solvent may include butane, bentane, hexane, isobentane,
Aliphatic hydrocarbons such as heptane, octane, and isooctane; alicyclic hydrocarbons such as cyclobentane, methylcyclobentane, cyclohexane, methylcyclohexane, and ethylcyclohexane; and aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene. Can be used.

These may be used in combination depending on the purpose. still,
When a solvent based on aliphatic hydrocarbons is used in the process of the invention, this means a solvent containing 5% by weight or more of aliphatic hydrocarbons. 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:
Examples 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 sacrificial 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 vinyl aromatic hydrocarbon polymers with Mn of at least 5000 are It is necessary to limit the amount added so that at least one coalesced block is formed. Further, in the method of the present invention, anti-gelling agents such as 1,2-butadiene, vinylacetylene, cyclobentadiene, primary and secondary amines, butyl chloride, butyl bromide, 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. The block copolymer mixture produced continuously in the continuous polymerization region in the method of the present invention is treated with a polymerization terminator such as water, alcohols, organic acids, and inorganic acids as necessary to deactivate the active sites of the living polymer. It is inactivated by adding sufficient amount to inactivate it.

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
H, one SH, one COO day, one COC1, S03 day, one C
Block copolymers having various functional groups such as triN at their ends can be obtained. If necessary, various stabilizers can be added to the block copolymer for the purpose of improving heat resistance, weather resistance, etc. The method of recovering the block copolymer mixture from the block copolymer mixture solution obtained by the method of the present invention includes, for example, a method of recovering the block copolymer mixture by precipitation using a precipitating agent such as methanol; A method of recovering a copolymer mixture by heating a solution to evaporate the solvent.Furthermore, a method of dispersing a block copolymer mixture solution in water, blowing steam, and heating to evaporate the solvent to recover a copolymer mixture. Any conventionally known method can be employed. The block copolymer compound obtained by the method of the present invention can be subjected to various processes such as hydrogenation, halogenation, hydrohalogenation, or introduction of carboxyl groups, ester groups, nitrile groups, sulfonic acid groups, etc. through chemical reactions. You may try to modify it.

Furthermore, the floc copolymer mixture may be added with various additives, such as calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, inorganic fillers such as clay, talc, glass beads, and glass fibers, and organic reinforcements such as carbon black. organic fibers such as carbon fiber and synthetic fibers, adhesives such as coumaronindene resin and terbene resin, crosslinking agents such as organic peroxide, inorganic peroxide and sulfur, paraffinic, naphthenic and aromatic oils, various pigments and dyes. , flame retardants, antistatic agents, lubricants, plasticizers,
It is also possible to use other fillers or mixtures thereof in appropriate amounts. The use of the block copolymer mixture 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,
Extrusion molded products such as hoses, window frames, sheets, and films; molded products made by thermoforming extruded sheets using vacuum, compressed air, etc.; injection molded products such as footwear and containers; blow molded products such as gun odor and household goods; and packing. It is used in press-molded products such as sheets, plates, etc., in adhesives as a solution, in latex by dispersing it in water, and in various packaging as films. Furthermore, the block copolymer can be mixed with natural rubber or various synthetic rubbers in any ratio, or mixed with polyethylene,
It is also a useful material to mix with one or a mixture of two or more of various thermoadhesive resins such as polypropylene, polystyrene, high-impact polystyrene, acrylonitrile-butadiene-styrene copolymer, etc. to measure its properties. Available. EXAMPLES The present invention will be described in more detail with reference to Examples below, but it goes without saying that the scope of the present invention is not limited thereto.

Example 1 Using a sliding polymer of a block copolymer consisting of (volibutadiene)-(polystyrene) obtained in an n-hexane solution using n-butyllithium as a catalyst, polymerization was carried out in a continuous polymerization apparatus such as the flow sheet shown in FIG. Continuous polymerization was performed.

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 with a nitrogen gas internal purge. was charged, then n-butyllithium was added as a catalyst, and the temperature was heated to 90°C at 70°C.
Polymerized for minutes.

Thereafter, an n-hexane solution containing styrene at a concentration of 2% by weight was added, and polymerization was continued at 50° C. for 2 hours. The amount of monomers and catalyst added were adjusted so that the polystyrene block of the block copolymer had an Mn of about 13,00 and a listyrene content of 62.5% by weight. The Mw/Mn of the polystyrene block was approximately 1.25. The polymerization vessel used here was used as a storage tank T in the next continuous polymerization process. In the continuous polymerization process, a stainless steel polymerization vessel with an L/D of approximately 4 is used.
-1, and a polymerization vessel with L/○ of about 8 was used as R-2.

In the polymerization vessel R-1, which had been internally purged with nitrogen gas and heated to a predetermined temperature, the above-mentioned block copolymer sliding polymer and putadiene were added, and in the polymerization vessel R-2, styrene was added at a weight ratio of 32. :48:20 ratio. Butadiene and styrene were each supplied as a 2% wt solution in n-hexane. The average residence time in the polymerization vessel R-1 and polymerization vessel R-2 was about 4 streaks 1 and about 35 minutes, respectively, and the polymerization temperature was about 90℃ on average, respectively.
Continuous polymerization was carried out at a temperature of about 7°C. Under these conditions, the conversion rate of butadiene or styrene at the outlet of each polymerization vessel was about 95% or more. Jeter is added to the block copolymer mixture solution continuously sent out from the polymerization vessel R-2.
Block copolymer polymer 1 using t-butyl-p-cresol and trisnonyl phasophosphite as a stabilizer
After adding 0.5 parts by weight per 00 parts by weight, the solvent was removed by heating to obtain a block copolymer mixture.

The resulting block copolymer mixture has a styrene content of about 39 to 41% by weight, and a block styrene content of about 38 to 41% by weight.
41% by weight, melt flow index (ASTMD-
12 spots - 5 spots, condition G) was 8-12. Further, the physical properties of this block copolymer compound are shown in Table 1. As shown in Figure 3, the obtained copolymer is a block copolymer having a composition distribution in which the styrene content decreases as the molecular weight increases, although the molecular weight distribution is a single peak (monomodal). It was a combined mixture.

The composition distribution shown in FIG. 3 was determined by measuring the differential styrene content of each developing solution (Z of 5) at the same time as measuring the molecular weight distribution by GPC. For GPC, LC-1 model manufactured by Shimadzu Corporation was used, and a differential refractometer and an ultraviolet absorption photometer were connected as detectors to the GPC, and measurements were carried out under the following conditions. 'E Column HSG40, 50, 60 [Row developing solution Tetrahydrofuran internal temperature 40°C] Next, as Comparative Example 1, the styrene content was approximately 4% by weight, the block styrene content was approximately 4% by weight, and the block styrene content was manufactured by the following conventional batch polymerization method. Table 1 shows the physical properties of the book copolymer with a melt flow index of about *% by weight and about 10, and the molecular weight distribution and composition distribution are shown in FIG.

A washed and dried polymerization vessel equipped with a rope sander and a jacket was purged with nitrogen, and an n-hexane solution containing 2 parts by weight of Ptagene la and 0.11 parts by weight of n-butyllithium were added thereto. After that, polymerization was carried out for 6 minutes at 70 qo.

Thereafter, an n-hexane solution containing 2 parts by weight of styrene, 4 parts by weight of butadiene, and 2 parts by weight of styrene at a concentration of 2% by weight, respectively, was sequentially added, and each was heated to 70°C.
Polymerization was carried out for 60 minutes at a time. The obtained block copolymer was post-treated in the same manner as in Example 1. Although the block copolymer of the present invention had a very wide compositional distribution, its physical properties were equivalent to those of the block copolymer of Comparative Example 1.

This is extremely contrary to the conventional basic idea that in order to obtain a block copolymer with excellent physical properties, especially tensile strength and impact resistance, the molecular weight distribution and composition distribution must be uniform. This is a noteworthy fact.
Table 1 Note) Physical properties were measured according to JIS K-6301.

In the continuous polymerization according to the method of the present invention, a block copolymer mixture that exhibits almost desired physical property values is produced at a relatively early stage when the solution of the polymerized block copolymer mixture starts to come out from the exit of the polymerization vessel R-2. A steady state was reached after about 3 powders, and thereafter a block copolymer mixture having the physical properties shown in Table 1 was stably and continuously obtained. or,
Continuous polymerization using the method of the present invention was carried out for 10 consecutive days, but there were no problems such as clogging of pipes etc. due to the formation of gel-like substances or large fluctuations in physical properties, and the operation continued stably. We were able to. Next, in order to clarify that the book copolymer mixture obtained above exhibits better properties than block copolymer mixtures obtained by conventional methods, the following tackiness test was conducted. went. In addition, as a block copolymer mixture obtained by a conventional method, block copolymers having a styrene content of 25% by weight and 55% by weight, which were produced in the same manner as in Comparative Example 1, were mixed in equal amounts, The composition used had a total styrene content of about 40% by weight, a block styrene content of about 3% by weight, and a melt flow index of about 10. The adhesive for the adhesion test consisted of 100 polymerized parts of a block copolymer mixture, 10 parts by weight of terbene resin, 3 parts by weight of naphthenic oil, and 2,5-di-tert-butylhydroquinone as a stabilizer. It was produced by heating and melting 3 parts by weight at about 180 oo.

The adhesive produced in this way was melted and
A kraft adhesive tape was made by applying it to kraft cardboard whose back was treated with . The creep characteristics of this kraft adhesive tape against touch and stainless steel were measured. Each measurement was carried out by the method shown below. For tack, adhesive tape is fixed on a plate having an angle of 30 degrees, and J. Ball No. 1 stopped on the surface of the adhesive tape using Dow's ball rolling method. was measured. The tack was measured at 2000.
For creep characteristics, adhesive tape and stainless steel plate are bonded so that the adhesive area is 250 x 25 ribs, the stainless steel plate is fixed, a load of lk9 is applied to the lower adhesive tape, and the adhesive tape peels off at an ambient temperature of 60°C. This was determined by measuring the time taken. As a result, the adhesive containing the block copolymer mixture of the present invention had a tack of 22 minutes and the creep property of 30 minutes, whereas the adhesive containing the block copolymer mixture obtained by the conventional method had a tack of 22 and a creep property of 30 minutes. were 1 and 20 minutes, respectively, and the adhesive containing the block copolymer mixture obtained by the method of the present invention showed superior properties.

The pressure-sensitive adhesive containing one block copolymer of Comparative Example 1 instead of the block copolymer mixture had a tack of 10 and a creep property of 10 minutes.

Examples 2 to 4 and Comparative Examples 2 and 3 Using a living polymer of polystyrene obtained in a cyclohexane solution using n-butyl lithium as a catalyst, a continuous polymerization apparatus with two polymerization vessels connected as shown in the flow sheet shown in Fig. 1 was used. Continuous polymerization was performed.

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 rope punch and the interior was purged with nitrogen gas. Then, n-butyllithium was added and polymerization was carried out at 50GO 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 2. Mw/Mn of the polystyrene obtained by this method was about 1.15. In addition, in order to obtain polystyrene with a wide molecular weight distribution, a portion of the styrene cyclohexane solution 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 2 were produced. The same polymerization vessel as in Example 1 was used for the continuous polymerization process. Continuously carried out in the same manner as in Example 1 except that the living polymer of polystyrene and butadiene supplied to polymerization vessel R-1 and the supply ratio of styrene supplied to polymerization vessel R-2 were set to 15:70:15 by weight, respectively. Polymerization was performed. The styrene content of the resulting block copolymer mixture is approximately 29-31% by weight.
The block styrene content was about 28-31% by weight, and the melt flow index was about 4-8. The physical properties of the obtained block copolymer mixture are shown in Table 2, but those obtained by continuous polymerization using a polystyrene living polymer in which either Mn or Mw or Mn is outside the scope of the present invention as a prepolymer are shown in Table 2. It can be seen that the tensile strength is extremely reduced.

All of the block copolymer mixtures shown in Table 2 had the same molecular weight distribution and composition distribution as in Example 1. 2nd
Table note) Physical properties were measured according to JISK-6301.

Example 5 and Comparative Example 4 Using IJ Bing polymer, a block copolymer consisting of polybutadiene (polystyrene) with a styrene content of 31% by weight, which was produced in the same manner as in Example 1, it was supplied to a polymerization vessel. The supply ratio of Bing polymer, butadiene, and styrene was 65% by weight, respectively.
Continuous polymerization was carried out in the same manner as in Example 1 except that the ratio was changed to 15:20.

In addition, M of the polystyrene flock of the above block copolymer
n was approximately 13,000, and Mw/Mn was approximately 1.25. Table 3 shows the physical properties of the obtained block copolymer mixture. In addition, when the molecular weight distribution and composition distribution of the obtained block copolymer mixture were measured, this block copolymer mixture showed a composition distribution in which the styrene content monotonically decreased as the molecular weight increased, and moreover, it showed a composition distribution in which the styrene content monotonically decreased as the molecular weight increased. The difference in styrene content between the components with high and low styrene contents in the main components excluding the high molecular weight components by 1% by weight was approximately 1% by weight. In addition, as Comparative Example 4, continuous polymerization was carried out in the same manner as above using a random copolymer sliding polymer with a styrene content of 31% by weight instead of a block copolymer sliding polymer with a styrene content of 31% by weight. However, a block copolymer with excellent tensile strength in an unvulcanized state could not be obtained.

The results are shown in Table 3. Table 3 Note) Physical properties were measured according to JIS K-6301K.

Example 6 A polystyrene living polymer obtained in the same manner as in Example 2 from the bottom of a stainless steel polymerization vessel with L/D of about 8, and a cyclohexane solution containing butadiene at a concentration of 2% by weight were added. Polymerization was carried out by continuously supplying a cyclohexane solution containing styrene at a concentration of 2% by weight from a supply port provided at a position 3/4 L from the bottom of the polymerization vessel.

The living polymer, butadiene and styrene were added continuously in 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 to about 90 oo on average from the bottom of the polymerization reactor to the styrene supply port, and about 80 oo on average from the styrene supply port to the top of the polymerization reactor. In this experiment, butadiene supplied from the bottom of the polymerization vessel and styrene supplied from the side of the polymerization vessel were polymerized in separate polymerization regions.
A perforated plate with a Sekiguchi ratio of approximately 30% was provided at the 4L position. The styrene content of the obtained block copolymer polymer is about 39-4
The block styrene content was approximately 33-3% by weight, and the melt flow index was 2-6. The physical properties are shown in Table 1. Furthermore, the molecular weight distribution and composition distribution of the block copolymer mixture were the same as in Example 1. Examples 7 and 8 The styrene content was approximately 70% by weight using the same method as in Example 1.
The block copolymer mixture of (Example 7) and the block copolymer mixture of Example 2
A block copolymer mixture (Example 8) having a styrene content of approximately 8% by weight was prepared in the same manner as in Example 8.

In Example 7, a mixed solvent of n-hexane:cyclohexane=70:30 (polymerization ratio) was used as the polymerization solvent. Table 4 shows the physical properties of the obtained block copolymer. All of these had a single peak (monomodal) molecular weight distribution, but the composition distribution showed an extremely wide distribution. The molecular weight distribution and composition distribution of the block copolymer of Example 8 are shown in FIG. In addition, in the block copolymer mixture of Example 7, the difference in styrene content between the component with a high styrene content and the component with a low styrene content is determined by the difference in styrene content between the component with a high styrene content and the component with a low styrene content in the main component excluding 1% by weight of each of the low molecular weight component and the high molecular weight component. It was approximately 1% by weight. Table 4 Note) The above physical properties were measured according to JISK-6871.

Example 9 IJ Bing polymer, a block copolymer made of (polybutadiene)-(polystyrene)-(polybutadiene) with a styrene content of 28.6% by weight, produced by the same method as in Example 1, was mixed with styrene in a ratio of 70:30. The weight ratio of about 4 L/○ was continuously fed to the polymerization vessel R-1 for polymerization.

Styrene was supplied as a 2 wt% n-hexane solution;
The average residence time in the polymerization vessel R-1 was set to about 4 minutes, and the polymerization temperature was set to an average of about 70°C. The obtained block copolymer polymer had a styrene content of about 49 to 51% by weight, a block styrene content of about 49 to 51% by weight, and a melt flow index of 10 to 15.

Moreover, the molecular weight distribution and composition distribution were as shown in FIG. Example 10 and Comparative Example 5 A cyclohexane solution containing a living polymer of polystyrene at a concentration of 20% by weight obtained in the same manner as in Example 2 from the bottom of a stainless steel polymerization vessel with a box frame having an L/D of approximately 6. and cyclohexane solution containing butadiene at a concentration of 20% by weight were each continuously supplied, and styrene was further added at a concentration of 2% by weight from a V supply port provided at a position 1/2 L from the bottom of the polymerization vessel. The cyclohexane solution containing the cyclohexane was continuously supplied to the vehicle.

The polystyrene living polymer used here had an Mn of 25,000 and an Mn/Mn of 1.15. The proportions of the living polymer, butadiene and styrene supplied to the polymerization vessel were 20:30:50 by weight, respectively, and the average residence time in the polymerization vessel was adjusted to about 4 hours. Further, the polymerization temperature was set at an average of about 80 oo. The styrene content of the obtained block copolymer polymer is about 69~
The block styrene content was approximately 37-4% by weight, and the melt flow index was approximately 1-5.

The molecular weight distribution of this block copolymer was a single peak molecular weight distribution, and had a composition distribution in which the styrene content monotonically decreased as the molecular weight increased. Furthermore, the difference in styrene content between the component with a high styrene content and the component with a low styrene content in the main component excluding the low molecular weight component and the high molecular weight component by 1% by weight was approximately 1 box weight%. Next, as Comparative Example 5, parts by weight of butadiene 3 and 50 parts by weight of styrene were added at a concentration of 2% by weight to a polymerization vessel containing parts by weight of the living polymer 2 of polystyrene as a 2% by weight cyclohexane solution. Polymerize by adding a cyclohexane solution to give a styrene content of about 7% by weight.
A floc copolymer having a block styrene content of about 3 box weight % and a melt flow index of about 3 was obtained.

In addition, when obtaining this block copolymer, a small amount of tetrahydrofuran was used as a randomizer to adjust the floxed styrene content to the above value. The obtained block copolymer had a uniform composition distribution as in Comparative Example 1. Next, Example 1 obtained above
Parts by weight of block copolymer polymer No. 0 or block copolymer 5 of Comparative Example 5 and parts by weight of polystyrene 5 were melt-kneaded to form a pellet, and then extruded into a sheet using a 25 side extruder. , sheets with a thickness of 0.3 sail were prepared, respectively.

Dart impact strength of the obtained sheet (ASTMD1709
As a result of measuring the sheet using the block copolymer mixture of Example 10, the dart impact strength was 8k9.
In contrast, the weight of the sheet using the block copolymer of Comparative Example 5 was 6 kg. Example 11 and Comparative Example 6 The block copolymer polymer of Example 8 and the block copolymer of Comparative Example 6 were each put into an injection molding machine (Toshiba IS-8MM).
A flat plate with a thickness of 3 skins was produced by injection molding.

Test pieces were cut from near the center of the flat plate in a direction parallel to and perpendicular to the injection direction, respectively, and taken out, and the Izod impact strength was measured. As a result, in the test piece using the block copolymer mixture of Example 8 (here referred to as Example 11), the difference in Izo impact strength between the direction parallel to the injection direction and the direction perpendicular to it was approximately 0.5k9. The block copolymer of Comparative Example 6 had a skin/skin notch, whereas the block copolymer of Comparative Example 6 had a difference in Izotz impact strength of approximately 1.0k9, and there was a skin/skin notch. It has become clear that molded pieces with less anisotropy can be obtained. The block copolymer of Comparative Example 6 was produced in the following manner.

The washed and dried flywheel machine and jacketed polymerization vessel were purged with nitrogen, and a cyclohexane solution containing 4 parts by weight of styrene at a concentration of 2% by weight and n-butyl lithium were added to it.
．． After adding 0 parts by weight to the box, polymerization was carried out for 6 minutes at 7,000.
Thereafter, a cyclohexane solution containing 20 parts by weight of butadiene and 4 parts by weight of styrene each at a concentration of 2% by weight was successively added, and polymerization was carried out in 6 portions at 7000°C. Post-treatment of the obtained block copolymer was carried out in Example 1.
I did it in the same way. The styrene content of the obtained block copolymer was 8% by weight, and the styrene composition distribution had a uniform composition distribution like the block copolymer of Comparative Example 1. Example 12 and Comparative Example 7 The block copolymer polymer of Example 8 and the block copolymer of Comparative Example 6 were each extruded into sheets using a 25-0 sheet extruder, and the thickness of the obtained sheet was determined as follows. It was measured as follows.

Each sample was extruded into a sheet through a die whose dip interval was adjusted to 0.3 mm in advance, and 2.5 mm was cut off from both ends of the obtained sheet.The thickness of the remaining sheet was measured in the direction perpendicular to the extrusion direction. Measurements were taken at 10 points at equal intervals, and the maximum and minimum values were compared. As a result, in the extruded sheet using the block copolymer mixture of Example 8 (herein referred to as Example 12), the difference between the maximum and minimum thickness was on the 0.03 side, whereas , an extruded sheet using the block copolymer of Comparative Example 5 (here, this is used as Comparative Example 7)
), it was 0.05 ribs, and it became clear that the block copolymer of the present invention could provide an extruded sheet with better thickness accuracy.

[Brief explanation of the drawing]

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 graph showing the molecular weight distribution (solid line) and the relationship between molecular weight and bound styrene content (dotted line) of the block copolymer mixture of Example 1.
FIG. 4 is a graph showing the molecular weight distribution (solid line) and the relationship between molecular weight and bound styrene content (dotted line) of the block copolymer mixture of Comparative Example 1 obtained by conventional batch polymerization. Figure 5 shows the molecular weight distribution (solid line) of the block copolymer mixture of Example 8 and the relationship between molecular weight and bound styrene content (
It is a graph diagram showing the dotted line). FIG. 6 is a graph showing the molecular weight distribution (solid line) of the block copolymer polymer of Example 9 and the relationship (score) between the molecular weight and the bound styrene content. T... Storage tank, R-1, R-2, R-3,
R-4... Polymerization vessel, 1-10... Piping, B... Conjugated Jen, A... Vinyl aromatic hydrocarbon, S... -Solvent, P...Block copolymer mixture. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. In an inert hydrocarbon solvent, (a) 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; A living polymer (hereinafter referred to as a prepolymer) having at least one vinyl aromatic hydrocarbon polymer block of less than In a continuous polymerization zone using a polymerization vessel, the prepolymer is continuously supplied to the first polymerization vessel, and at the same time, a monomer mainly composed of vinyl aromatic hydrocarbons is supplied to the first or subsequent polymerization vessels. Alternatively, a monomer mainly composed of a conjugated diene is continuously supplied for continuous polymerization, or a monomer mainly composed of a vinyl aromatic hydrocarbon and a monomer mainly composed of a conjugated diene are polymerized in substantially separate polymerization regions. The polymer block to be produced is continuously polymerized by continuously supplying each of them separately so as to be polymerized at By widening the molecular weight distribution of at least one of the polymer blocks, a polymer block mainly composed of at least two vinyl aromatic hydrocarbons and a polymer block mainly composed of at least one conjugated diene are formed. A method for continuously producing a mixture of block copolymers having 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 according to 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
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. The method according to claim 1, wherein a prepolymer obtained by a polymerization method consisting of batch polymerization, semi-batch polymerization, or a combination thereof is used in the state of a living polymer. 8 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 consecutive polymerization vessels in series, and the monomer obtained in the odd-numbered polymerization vessel is 2. The method according to claim 1, wherein the living polymer is continuously supplied to even-numbered polymerization vessels, and at the same time, a monomer mainly composed of vinyl aromatic hydrocarbons is continuously polymerized in the polymerization vessels. 9 The prepolymer is a vinyl aromatic hydrocarbon polymer, or 1
When a living polymer, which is a block copolymer consisting of a polymer block mainly composed of conjugated dienes and a polymer block mainly composed of a vinyl aromatic hydrocarbon, is continuously fed 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 continuously fed to the second polymerization vessel. 9. The method according to claim 8, wherein the monomer mainly consisting of vinyl aromatic hydrocarbon is continuously fed to the second polymerization vessel while being fed continuously. 10 A patent for polymerizing a monomer mainly composed of vinyl aromatic hydrocarbons and/or a monomer mainly composed of conjugated dienes by separately supplying them to at least one polymerization vessel from two or more supply ports in a continuous polymerization region. The method according to claim 1. 11 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 1: Continuously supplying a monomer mainly composed of vinyl aromatic hydrocarbons
The method described in item 0. 12 The prepolymer is a vinyl aromatic hydrocarbon polymer or a block copolymer consisting of a polymer block mainly composed of one conjugated diene and one polymer block mainly composed of vinyl aromatic hydrocarbon. A living polymer is continuously supplied from the bottom of one polymerization vessel, and a monomer mainly consisting of a conjugated diene is further continuously supplied from the bottom of the polymerization vessel, and at the same time at least one
Claim 1, in which a monomer mainly composed of vinyl aromatic hydrocarbons is continuously supplied through two supply ports for polymerization.
The method described in Section 1. 13. The method according to claim 1, wherein the polymer block that widens the molecular weight distribution has a ratio of weight average molecular weight to number average molecular weight of 1.3 or more. 14. The method according to claim 13, wherein the polymer block that broadens the molecular weight distribution is a polymer block mainly composed of a conjugated diene.