JPH01259016A - Composite polymerization - Google Patents

Abstract

PURPOSE:To obtain composite polymer as raw material rubber having excellent physical properties and processability by polymerizing butadiene solution with catalysts such as Ba compound and organic Li compound, etc., almost in trans bonding and successively adding organic Li compound and polymerizing in a slight fraction of trans bonding. CONSTITUTION:A monomer mixture solution comprising butadiene and inert solvent (e.g., n-hexane) is prepared and polymerized with a catalyst containing barium, strontium or calcium compound and organic lithium compound or organic magnesium compound at a temperature of 0-150 deg.C, to 70% or more fraction of trans bonding of butadiene, and subsequently, further organic lithium compound is added to said catalyst and polymerized at a temperature of 30-200 deg.C to 60% or less fraction of trans bonding of butadiene, then inert solvent is removed from produced complex polymer to afford the aimed complex polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a composite polymer, which is a raw rubber having excellent physical properties and processability. More specifically, polybutadiene blocks with 70% or more trans bonds and 60
The present invention relates to a method for producing a composite polymer whose main components are a block polymer consisting of a polybutadiene block having a trans bond of 60% or less and a polybutadiene block having a trans bond of 60% or less.

[Conventional technology]

The following three methods are known as polybutadiene with high trans bonds, for example, 70% or more trans bonds, and methods for producing the same. (1) A method using a Ziegler catalyst consisting of a transition metal compound and an organometallic compound (2)
) A method using an anionic polymerization catalyst containing an alkaline earth metal compound as a main component; (3) A method using a catalyst containing a rare earth metal compound as a main component.

The method (1) described above is known to carry out highly stereoregular polymerization using transition metal compounds such as nickel, Kobal 1~, titanium, and vanadium as main components. As a method for polymerizing butadiene using a metal, there is a method using a carrier of a tetravalent titanium metal compound and a magnesium halide (Japanese Patent Application Laid-open No. 67387/1987). Furthermore, when the main component is a vanadium compound, a polymer having an extremely high trans-coupling ratio can be obtained. For example, there is a method of polymerizing isoprene using a composite catalyst of tetravalent vanadium halide and organoaluminum (Japanese Patent Application Laid-open No. 36585/1985), and a method of polymerizing isoprene using a composite catalyst of tetravalent vanadium halide and organoaluminum (Japanese Patent Application Laid-open No. 36585/1985); A method of polymerizing isoprene using a composite catalyst consisting of a titanium compound and a titanium compound (JP-A-49-29386, JP-A-50-
No. 122586), etc. are known.

Methods belonging to the second method include those whose main components are barium, strontium, and calcium compounds, such as barium-di-tert-butoxide and organic lithium (Japanese Unexamined Patent Publication No. 47-3728), or barium- Di-tert-butoxide and organic magnesium (Unexamined Japanese Patent Publication No. 5
2-48910), etc., and furthermore, an organic compound of barium or strontium, an organic lithium, and (1) or (2). A method of preparing a conjugated diene using an organometallic compound of a metal (JP-A-52-30543) is also known.

Further, as a method belonging to the third method, a composite catalyst is known in which a rare earth metal compound is used as a main catalyst and an organomagnesium compound is used as a co-catalyst. For example, JP-A-59-1508 proposes a method using barrichic acid salts of Di, Nd, pr, etc., or special α, γ-dikene complexes.

In addition, JP-A No. 61-19611 proposed a method using a similar catalyst system using a compound of cerium and europium, and JP-A No. 61-97311 proposed a similar catalyst system using a lanthanum compound as the main catalyst, and a butadiene polymer with a high trans bond was proposed. is obtained efficiently.

Furthermore, it is also known to polymerize butadiene to 60% or less trans bonds using an organolithium compound as a catalyst.
M. Saltman (ed.), Chapter 4, published in 1977). Here, we have shown that a polymer with 48 to 50% trans bonds can be obtained by polymerizing butadiene with lithium metal or an organolithium compound in a nonpolar solvent, and that the addition of a polar compound to this system increases the number of bonds by 1.2. It has been reported that this leads to a decrease in 1,4 bonds.

There is also a proposal regarding a composite polymer in which one of the components is a block polymer of a butadiene copolymer with a high trans bond and a butadiene copolymer with a high vinyl bond, and a method for producing the same (Patent No. 11-238845).

According to the specification (Claim 1), "A composition comprising a rubber polymer selected from the group consisting of:

(2) Diblock copolymer of high 1 to lance coelectric material/high vinyl polymer.

■, Blend of high 1 to lance coelectric material and high vinyl polymer.

(2) A blend or mixture of a diblock copolymer of a high trans copolymer/high vinyl polymer, a high trans copolymer, and a high vinyl polymer.

a), where the high trans copolymer is butadiene-1,
3 and at least one copolymerizable monomer selected from the group consisting of styrene and isoprene, having a T (7) of less than about -70°C, and containing about 75 to 75 in the butadiene segment. The composition has a total content of 85% trans units and up to about 8% vinyl units.
It accounts for 0ii%.

b), the high vinyl polymer comprises at least one monomer selected from the group consisting of homopolybutadiene, styrene and imprene, and at least one monomer selected from the group consisting of a copolymer of 7-tadiene-1,3. It is a combination, about -7
It has a Tg greater than 0°C and no more than about -35°C and has about 40 to 80% vinyl units in the butadiene segment.

C) Also in the composition, the total amount of styrene and/or isoprene is about 5 to about 20% by weight, and the amount of vinyl groups is about 30 to 60%. '', and a method for producing this polymer composition is shown in claim 9, the gist of which is shown in the specification as follows.

r 1ITs8F? -b-11ν381? The process for making the copolymers involves copolymerizing butadiene and styrene in cyclohexane to a conversion of about 60 to 95%, preferably about 85%, using an organomagnesium compound and an organoaluminum compound, or an organomagnesium/organoaluminum compound. HTSBR (Block A) is formed using the barium salt of the alcohol combined in gB3, followed by a sodium (preferred), potassium or rubidium alcoholade, or a mixture thereof, and a strong Lewis acid, and optionally additional monomers. Add IVsBR (Block B)
It consists of forming.

The resulting SBR has a predominantly randomly distributed styrene unit in each block. Transformer-1 opened in block A,
I! The high content of 1-configuration is indicated by DSC (differential scanning
Calorimetry (differential scanning calorimetry) and crystalline melting point give rise to some degree of crystallinity, but the crystalline melting point can be adjusted to room temperature (by adjusting the lance-1,4 content and styrene level). (approximately 25° C.) or even lower. The resulting polymers have reduced cold flow and excellent processability. [Problems to be Solved by the Invention] However, in the above method, since the first block of the obtained polymer is a high 1 to lance copolymer, the Tg value is higher than that of a homopolymer. The Tl1iff (crystal melting point) is also low or non-existent, and the high trans block portion provides excellent physical properties as a rubber (
(Improved cold flow properties, improved hardness, improved modulus, improved wear resistance, etc.) are achieved in an instant. On the other hand, increasing the proportion of the high trans copolymer portion higher than necessary to achieve this effect was not desirable, as it resulted in exothermic properties and deterioration in low-temperature performance.

In addition, by carrying out the second stage polymerization to form this block by adding sodium alcoholade, etc., the second block inevitably becomes a polymer with a high vinyl content, 1''V SBR, and is generally Therefore, it cannot be applied to BR (polybutadiene rubber) or SBR (styrene-butadiene copolymer rubber) with a low vinyl content, which require improvements in cold flow, hardness, modulus, and strength.

[Means to solve the problem]

The present invention solves the above-mentioned problems at once.The present invention is a block consisting of a polybutadiene block having 70% or more trans bonds and a polybutadiene block having 60% or less trans bonds, which have excellent physical properties and processability. The present invention proposes a method for producing a composite polymer whose main components are a copolymer and polybutadiene having 60% or less of trans bonds. However, the present invention includes (a) a step of preparing a monomer mixture consisting of butadiene and an inert solvent, (b) a step of preparing a monomer mixture consisting of butadiene and an inert solvent, and (b) a step of preparing a monomer mixture consisting of butadiene and an inert solvent; Butadiene at a temperature of ~150°C
% or more of trans bonds, (c) Subsequently, adding an organolithium compound to the above catalyst and polymerizing butadiene to 60% or less of 1 to lance bonds at a temperature of 30 to 200°C, (d ) A method for producing a composite polymer comprising the step of removing an inert solvent from the obtained composite polymer.

The first step in the present invention is a step of preparing a monomer mixture consisting of butadiene and an inert solvent. The inert solvent used is not particularly limited as long as it does not deactivate the catalyst used, but n-pentane, n- -4 non, n
Preferred are aliphatic or alicyclic hydrocarbons such as -hebutane and cyclohexane, and aromatic hydrocarbons such as benzene and toluene. Moreover, these may be a mixture of two or more types, or may contain a small amount of impurities. The monomer mixture is prepared at a monomer concentration of 1 to 50% by weight, preferably 5 to 30% by weight, and contains arenes such as propadiene, etc. in a molar ratio of 1 or less to the organolithium compound.
1,2-butadiene, 1,2-pentadiene, 1,2-
It may also contain octadiene or the like. Furthermore, the mixed solution contains isoprene as a monomer component that can be copolymerized with a small amount of other butadiene as a polymer component other than butadiene.
2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2,4-hexyladiene, 2-phenyl-1
, conjugated diene of 3-butadiene, or styrene,
It may contain aromatic vinyl hydrocarbons such as α-methylstyrene, vinyl-1-luene, methoxystyrene, divinylbenpine, and 1-gonylnaphthalene.

The second step of the present invention is a step of polymerizing butadiene to 70% or more trans bonds at a temperature of 0 to 150°C using a catalyst containing barium, strontium, or calcium compounds and an organolithium compound or an organomagnesium compound. is. Catalysts that can be used in this step include the following catalysts containing barium, strontium, calcium compounds and organolithium or organomagnesium compounds that can polymerize butadiene to a high trans state. Catalyst consisting of tertiary butoxide and organolithium (Japanese Patent Publication No. 47-3728) (b) Catalyst consisting of barium di-tertiary alkoxide and dibutylmagnesium (Japanese Patent Publication No. 52-48910) (c) Comprising a barium compound of the following formula and organolithium Catalyst (JP-A-52-9090
(d) Catalyst consisting of a barium or strontium compound, an organolithium compound, and an organometallic compound of I[B or mA (Japanese Patent Publication No. 52-30543) (e) Me (
MR1R2R3R4)2 or Me (M'R'
4) (In the formula, Me is barium, calcium, strontium,
(M represents boron or zinc) and an organometallic compound of organolithium (JP-A-52-17591);
A tactile a made of alkaline metals such as alcolade! (Unexamined Japanese Patent Publication No. 52-98077) A catalyst consisting of an organic compound of (t)barium and an organolithium/magnesium compound, or a catalyst consisting of these and an organoaluminium compound.
JP-A-55-38827, JP-A-56-112916
).

Preferred barium, strontium and calcium compounds used in the present invention are organic compounds of barium, which can be expressed by the following formula, and particularly preferred are alcoholade or phenol salts of barium.

(a) Ba+Y R)2 (wherein R is selected from aliphatic, alicyclic or aromatic hydrocarbon groups, and Y is oxygen or sulfur atom).

Examples of these include barium salts of the compounds listed below.

That is, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, tert-butyl alcohol, n-hexyl alcohol, cyclohexyl alcohol, 7lyl alcohol, cyclopentenyl alcohol,
Benzyl alcohol, phenol, cabucol, 1-naphthol, 2,6-tert-butylphenol,
2,4,6-]]~tert-butylphenolnonylphenol, 4-phenylphenol, ethanthyl, 1-butanethyl, thiophenol, cycloheyalyanthiol, 2-naphthalenethiol, caprylic acid, lauric acid, myristic acid, palmitic acid , suderic acid, oleic acid, linoleic acid, liluic acid, naphthoic acid,
Benzoic acid, hexythylic acid, decanetylic acid, tridecanethionolic acid, thiobenzoic acid, tert-carbonic acid
These include butyl, acidic hexyl carbonate, acidic phenyl carbonate, thioacidic tert-butyl carbonate, dimethylamine, diethylamine, di-n-butylamine, and the like.

Further, examples of organic lithium compounds include the following. Namely, ethyllithium, n-propyllithium, iso-propyllithium, n-butyllithium, isoamyllithium, 5ec-amyllithium,
n-hexyllithium, n-octyllithium, allyllithium, n-propenyllithium, iso-butenyllithium, benzyllithium, phenyllithium, 1,1
- diphenyllithium, tetramethylene dilithium, pentamethylene dilithium, hexV methylene dilithium,
diphenylethylene dilithium, tetraphenylethane dilithium, 1,5-dilithium naphthalene, 1,4-
dilithiocyclohexane, polybutadienyl lithium,
These include polyisobutenyllithium, polystyryllithium, etc.

Furthermore, the organomagnesium compound can be expressed by the following formula.

2Mg (wherein R is selected from aliphatic, cycloaliphatic or aromatic hydrocarbon groups).

Examples of organomagnesium compounds include: Namely, diethylmagnesium, di-n-propylmagnesium, di-iso-propylmagnesium, di-n-butylmagnesium, di-tert-butylmagnesium, di-n-hexylmagnesium, di-n-propylmagnesium, diphenylmagnesium, etc. .

In the present invention, when the above-mentioned organolithium compound and organomagnesium compound are used together, they are mixed in advance,
Using the catalyst as an organolithium-magnesium compound through reaction increases the solubility of the catalyst in the polymerization solvent, and is a preferred embodiment.

Further, in this embodiment, it is also a useful method to use an organoaluminum compound in combination, examples of which include organoaluminum compounds expressed by the following formulas, with trialkylaluminum being particularly preferred.

R3A, l! (wherein R is selected from aliphatic, alicyclic or aromatic hydrocarbon groups).

Examples of organoaluminum compounds include the following: Tsunawara, tri-1so-butylaluminum,
These include tri-n-propyl aluminum, tri-1so-propyl aluminum, and the like.

The amount of catalyst used in the present invention is barium, strontium,
Alternatively, it is preferably 0.005 to 50 or 0.01 to 10 mmol per 100 grams of calcium compound.

The polymerization is carried out using the above-mentioned catalyst at 0°C to 150°C, preferably 30 to 120°C, and the polymerization format may be a batch method or a continuous method. Polymerization of butadiene at 70%
% or more of trans bonds, and this (
The proportion of the high trans polymer polymerized in step b) in the total composite polymer is 1 to 70% by weight, preferably 3 to 60% by weight.
The polymerization is allowed to proceed so that the amount becomes 5% by weight, more preferably 5 to 50% by weight.

In the next step (c), an organolithium compound is subsequently added to the above catalyst, and butadiene is polymerized to 60% or less of trans bonds at a temperature of 30 to 200°C. Suitable examples of the organic lithium compounds to be added include methyllithium, ethyllithium, "]-propyllithium,
Isopropyllithium, n-butyllithium, 5e
c-butyllithium, tert-butyllithium, isoamyllithium, 5ec-amyllithium-n-hexyllithium, n-octyllithium, allyllithium,
Benzyllithium, phenyllithium, 1,1-diphenyllithium, 1-heramethylene dilithium, pentamethylene dilithium, 1,2-dilithio-1゜1.2.2
-tetraphenylethane, 1,3-bis(1-lithio-
Examples include 1,3-dimethylpentyl)benzene.

Preferably, n-butyllithium, 5ec-butyllithium, tert-butyllithium, 1,3-bis(1-
Examples include organic lithium compounds such as lithio-1,3-dimethylpentyl)benzene.

The amount added is 0.1 to 1 per 100 grams of nanatsumar.
0 mmol, preferably 0.3 to 5 mmol. In addition, at the same time as the organolithium compound added later, the polymerization activity of the catalyst is increased, or the 1,2 vinyl bond is increased,
Lewis bases can be used to further reduce trans coupling.

Lewis bases that can be suitably used include ethyl, thioethers, and amines, such as ethers such as dimethyl ether, diethyl ether, diphenyl ether, tetrahydrofuran, anisole, and diglyme, dimethylamine, diethylamine,
Amines such as trimethylamine, triethylamine, di-n-butylamine, aniline, diphenylamine, N-ethylaniline, N, N, N=, N-~tetramethylethylenediamine, dipiveridinoethane, as well as thiophene, tetrahydrothiophene , 2.5-dihydrothiophene and the like. Preferably diethyl ether, tetrahydrofuran, triethylamine, N.

N, N-, N=-teramethylethylenediamine. The strength of the electron-donating compound to be used varies depending on the strength of the compound as a Lewis base; good. The preferred amount used is about 0.01 to 50 moles per mole of the organolithium compound. Polymerization is carried out at 30 to 200°C using the above-mentioned organolithium-containing catalyst.
, preferably at a temperature of 50 to 150°C. At this stage, the monomer mixture prepared in step (a) or the monomer mixture prepared in another composition may be introduced into the polymerization system.

In this case, both the residual monomer that was unreacted in step (b) and the monomer introduced in step (c) are converted into (c)
It is polymerized in the process. The monomer polymerized in step (c) is butadiene alone or a mixture of butadiene and a heptamer copolymerizable with butadiene. 1,3-butadiene, 1,3-pentadiene, 2,4
- Conjugated dienes such as hexadiene, 2-phenyl-1,3-butadiene, or styrene, α-methylstyrene,
These are aromatic vinyl hydrocarbons such as vinyltoluene, methoxystyrene, divinylbenzene, and 1-vinylnaphthalene.

In the polymerization in this step, butadiene is polymerized to 60% or less, preferably 55% or less of 1-Herans bonds, and the proportion of the low trans polymer polymerized in this step (c) in the total composite polymer is Polymerization is allowed to proceed so that the weight ratio is 30 to 99% by weight, preferably 40 to 97% by weight, and more preferably 50 to 95% by weight.

When the polymerization reaction reaches a predetermined polymerization rate, a known polymerization terminator is added to the reaction system to stop the polymerization reaction, and the usual steps of solvent removal and drying in the production of conjugated diene polymers can be performed.

The composite polymer obtained by the method of the present invention consists of a rubbery or resinous polybutadiene block polymerized with 70% or more of high 1-lance bonds and a rubbery polybutadiene block polymerized with 60% or less of trans bonds. The main components are block polymers consisting of blocks and polybutadiene with 60% or less trans bonds, and the molecular weight of the polymer can be controlled by adjusting the composition or concentration of the catalyst used, ranging from several thousand to several tens of thousands. The range is 10,000. Furthermore, the molecular weight distribution of the polymer can be controlled by adjusting the composition of the catalyst used, and MW/Mn is 1.1 to 5.
．． However, in order to obtain preferable physical properties, 1.
It should be in the range 1-4.0.

In addition, known coupling reaction techniques such as coupling agents using reactive ends of living polymers such as ester compounds, polyepoxy compounds, halogenated hydrocarbon compounds, halogenated silicon compounds, and halogenated tin compounds, or polyfunctionality such as divinylbenzene It is also possible, if necessary, to impart a branched structure to the polymers or to expand the molecular weight distribution, for example, by adding a hexamer to the combination system during or after the polymerization.

The applications of the polymers obtained by the process of the invention are wide based on their polymer structure and properties.

For example, it can be used as a rubber-like polymer for tire treads, carcass, void walls, etc., and exhibits excellent properties such as processability, abrasion resistance, and heat generation properties.

In addition, even when a toughening agent such as polystyrene is used to improve impact properties, it shows no cold flow properties, and has excellent particle size control, balance of rigidity and impact resistance, and environmental stress cracking resistance (ESCR) against oil. impact polystyrene (IIPs).

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Examples 1 to 3 Three sufficiently dried 700 pressure glass bottles were capped and the insides were purged with dry nitrogen for 3 hours.

After sealing 300 gn-hexine mixture containing 1,3-butadiene of 603 in a bottle, each contains 0.1 mmol of barium strontium and calcium dinonyl phenoxide, 0.15 mmol of n-butyllithium, and 0.15 mmol of dibutylmagnesium. mmol was added and black marketed at 60° C. for 2 hours. After unpulling a portion for 4 hours, 1.0 mmol of n-butyllithium was further added to the mixture, and polymerization was further carried out at 100° C. for 1 hour. After polymerization, methanol was added to stop the reaction, and the polymer was precipitated and separated with a large amount of methanol, followed by vacuum drying at 50°C.
A composite polymer was obtained. Table 1 shows the analytical values of this composite polymer and samples taken during the process.

(Left below) Example 4 Internal volume: 10! At J, two stirrer and jacketed reactors made of stainless steel with a height-to-inner diameter ratio (L/D > 4) are connected in series, and from the bottom of the first reactor 1,3-butadiene is -Hekylin solution and barium dinonyl phenoxide, dibutylmagnesium, butyllithium and triethylaluminum as catalysts were continuously fed and polymerization was carried out while keeping the inside at 70°C.The concentration of the monomer mixture was 18% by weight. , the feed rate of the Nanatsuma was 0.67Kg/hr.The feed amount of the catalyst was per 100g of the Nanatsuma, and the barium nonyl phenoxide was 0.
．． 15 mmol, dibutylmagnesium 0.20 mmol, butyllithium 0.20 mmol, and triethylaluminum 0.30 mmol.

The conversion was measured by limp ringing from the outlet of the first reactor and was found to be 33.4%, and the microstructure of the obtained polymer was 85% trans, 4% vinyl, and 11% cis. The average molecular weight by GPC is Mw
= 55,000, Mn = 22,000, and the GPC shape was one gentle mountain.

The polymer solution from the first unit is introduced into the bottom of the second unit, and additional 1,3-butadiene n-hex is added from the bottom of the second unit]
Non-solution and n-butyllithium were introduced. The concentration of the monomer mixture introduced into the second reactor was 18% by weight.
The feed rate was 0.67 KFI/hr. The amount of butyllithium introduced into the second reactor was 2.0 mmol per 100 g of monomer introduced into the second reactor. After polymerization was carried out while maintaining the internal temperature of the second reactor at 120°C, 0.6 phr of 2,4-ditertiary-butyl-p-cresol was added to the polymer solution exiting the second reactor. 10
The solvent was removed by continuous mixing (parts by weight per 0 parts by weight of rubber), introduction into hot water and steam stripping. The obtained rubber was dried with a hot roll.

Conversion at the second exit was 99.8%.

The microstructure of the obtained rubber was 57% trans, 11% vinyl, and 32% cis, and the Mooney viscosity was MLl, 4.
(100℃) 30, the average molecular foot by GPC is Mw
= 1e million, Mn = 67,000, and the GPC shape was one gentle mountain.

The final polymer of Example 4, the intermediate V-pulling polymer of Example 4, and the trans-containing polymer polymerized with n-butyllithium alone! 52%, weight average molecular layer 1 of 100,000 polymers
An attempt was made to separate the /1 blend.

Each polymer 23 was dissolved by heating in a mixed solvent of n-hekirin/cyclobequinone 100%, and then cooled to 0° C. and centrifuged to separate a precipitate and a solution. The analytical values of this product are shown in Table 2. Table 2 suggests that the composite polymer, which is the final polymer of Example 1, contains almost no high trans resinous polybutadiene homopolymer, and the main component is a block polymer.

(Left below) As described above, the obtained rubber is a composite material whose main component is a block polymer consisting of 15% by weight of 85% trans polybutadiene block and 85% by weight of 50% trans polybutadiene block. It was a polymer.

When the cold flow of the obtained rubber was measured, it was found that there was substantially no cold flow.

Rubber of Example 4 = No cold flow after 3 days Diene 3
5 (Commercial product) Collapses in two and a half days.

(3 an x 3 an on a 30° inclined table
A rectangular parallelepiped rubber sample of X10cI11 (height) is fixed,
The slope situation was observed. ) Example 5 Using the same reactor as in Example 4, the first polymerization was carried out in the same manner.

Similarly, the polymer solution from the first reactor is introduced into the bottom of the second reactor, and from the bottom of the second reactor, an additional heptamer mixture consisting of 1,3-butadiene, styrene, and n-hekyrin and n-butyl Introduced lithium.

The concentration of the monomer mixture was 26%, the feed rate of 1,3-butadiene was 0.69/(y/hr, and the feed rate of styrene was 0.46 Kg/hr. 1. From the bottom 2/3 of the height of the vessel.
Additional heptamer mixture consisting of 3-butadiene, n-bequinone was introduced. The concentration of this monomer mixture is 26
% weight, feed rate of 1,3-butadiene is 0.41
Kg/hr.

The amount of n-butyllithium introduced into the second base was 2.0 mmol per 100 U of the total heptamine introduced into the second base. After polymerization was carried out while maintaining the internal temperature of the second reactor at 120°C, 2,4-ditertiary-butyl-p was added to the polymer solution exiting the second reactor in the same manner as in Example 5.
-Cresol was added and rubber was obtained in the same manner.

The conversion at the outlet of the second unit was 99.5% for 1,3-butadiene and 98.5% for styrene. The microstructure of the obtained rubber was measured by Hampton's method using an infrared spectrophotometer, and it was found that the combined styrene content was 20.5%.
, the microstructure of the polybutadiene part is 1 to 57%,
11% vinyl, 32% cis, Mooney viscosity is ML
l+4 (100°C) 40, the average molecular weight by GPC was Mw = 170,000, Mn = 73,000, and the GPC form was a gentle single peak. Further, the amount of block styrene gold was 0.1% by weight based on the total rubber. The measurement of blocked styrene was carried out by the osmic acid decomposition method (J, Poly, Sci, 1,429 (1946)). When the obtained composite polymer was fractionated in the same manner as in Example 4, the precipitate was The amount is 1.3% by weight based on the composite polymer, suggesting that this polymer is also a block polymer.

As described above, the obtained rubber contains 10% by weight of 85% trans polybutadiene block and 25% by weight of bound styrene.
, random SBR of 52% trans in polybutadiene part
It was a composite polymer whose main component was a block polymer consisting of 901% by weight of blocks.

Comparative Example 1 A sufficiently dried 700 d pressure glass bottle was capped, and the inside was further purged with dry nitrogen for 3 hours. 239 1,3
- After sealing 135 g of cyclohekirin mixture containing butadiene and 4 g of styrene in a bottle, Ba-Mg-AN
Initiator (Ba/M(II/AJ2=0.18/
0.57 / 0.04 units mmol / 100g monomer, as described in U.S. Pat. No. 4.297.240)
was added, and polymerization was carried out at 60°C for 1 hour. After 4 non-pulling of a portion, 165 g of a cyclohexane mixture containing 33 of 1゜3-butadiene and M
a Cyclohexane solution of tertiary amylate and TMEDA (
Na/Mg mo/L/ratio = 0.77, TMEDA/M
The g molar ratio was adjusted to 0.61. ), 50
Polymerization was carried out for 1 hour at .degree. Thereafter, methanol was added to stop the reaction, and a polymer was obtained in the same manner as in Example 1. Table 3 shows the analytical values of the obtained polymer and the intermediate V-amplified product.

Comparative example 2 It was carried out in the same manner as in Comparative Example 1.

However, Ba-Mc+-A, l) with the addition of an initiator, 6
Polymerization was carried out at 0°C for 5 hours, Na tertiary amylate and TMEDA were added thereto, and polymerization was carried out at 50°C for 1 hour. The results are shown in Table 3.

In the TSBR polymer that was limped during the process, crystallization by trans did not occur and the precipitate could not be decomposed by the same method as in Example 1 using a mixed solvent of n-hexane/cyclohexane.

Moreover, the polymer finally obtained was also the same.

Furthermore, the cold flow properties of the obtained polymer were evaluated by the method shown in Example 4, and were found to be ``collapsed in one day'', which was not preferable.

(Left below) [Effects of the Invention] As is clear from the above Examples and Comparative Examples, the composite polymerization method of the present invention can produce a composite polymer BR (polybutadiene rubber) with excellent cold flow properties and a relatively low vinyl cycle. or S
This provides an extremely efficient method for obtaining BR (styrene-butadiene copolymer rubber).

Special γF applicant: Asahi Kasei Industries, Ltd. Agent: Patent Attorney Hajime Nozaki Procedure Ne City Sho 8 (voluntary) May 23, 1999

Claims (1)

[Claims] 1 (a) A step of preparing a monomer mixture consisting of butadiene and an inert solvent, (b) A process of preparing a monomer mixture consisting of butadiene and an inert solvent, (b) using a catalyst containing barium, strontium, a calcium compound and an organolithium compound or an organomagnesium compound Butadiene at a temperature of 150℃
% or more of trans bonds, (c) Subsequently, adding an organolithium compound to the above catalyst and polymerizing butadiene to 60% or less of trans bonds at a temperature of 30 to 200 ° C., (d) obtaining A method for producing a composite polymer comprising the step of removing an inert solvent from the composite polymer obtained.