JP2003246815A - Polymerization method of butadiene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymerization method, where in the polymerization method of butadiene, a polymer having a lower melting point than that in a conventional method can be polymerized, and a polymer having a narrow melting point distribution can be polymerized and agglomerates at the polymerization are suppressed so as to make the polymer color to approximate to a white color. <P>SOLUTION: The polymerization method of butadiene is characterized by using a catalyst comprising an aged liquid (ingredient A) which is obtained by contacting (a) a cobalt compound and (b) a I to III group organometallic compound or a hydrogenated metallic compound, a compound (ingredient B) selected from a group consisting of carbon disulfide, phenyl isothiocyanate and xanthogenic acid compounds, and an oxide or chelate (ingredient C) in the presence of a conjugated diene. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for polymerizing butadiene.

[0002]

2. Description of the Related Art Polybutadiene having a syndiotactic 1,2-structure as a main structure (hereinafter referred to as "SPB") has a vinyl group in its side chain, and therefore has reactivity with other polymers and elastomers. Is expected to be high. Also, 1
It is known that a resin having a relatively high melting point of about 50 ° C. or higher is a tough resin. Therefore, SPB is expected to have a wide range of uses as a reinforcing material for various rubbers or as a raw material for polymer alloys.

SPB is a cobalt compound, Nos. I-III.
It was known that it can be obtained by polymerizing 1,3-butadiene using a catalyst composed of a group-group organometallic compound and carbon disulfide (Japanese Patent Publication No. 47-19892 (Patent Document 1)). Japanese Patent Publication No. 47-19893 (Patent Document 2) and the like). As the polymerization process, non-aqueous solvent polymerization, aqueous suspension polymerization process and the like are known. For example, Japanese Patent Publication No. 62-58613 (Patent Document 3) discloses a cobalt compound and Nos. I to II.
It is disclosed that carbon disulfide is added to a catalyst aging solution prepared by contacting a Group I organometallic compound with 1,3-butadiene to produce SPB.

However, in the above aqueous suspension polymerization method, the melting point (by the measuring method described later) measured by DSC is used.
In the case of producing a polymer having a temperature of 130 ° C. or lower, it is necessary to add a large amount of a melting point adjusting agent such as acetone, suspension polymerization tends to be unstable, and improvement in yield has been required. Further, the melting point distribution of the polymer obtained by the conventional aqueous suspension polymerization is wide, and in particular, due to the presence of the endotherm on the low melting point side, the heat resistance property may be inferior to the polymer having the sharp melting point distribution of the same melting point. Also, from a manufacturing perspective,
A lump component was likely to be formed during the polymerization, and the obtained polymer had a light brownish white color, which was sometimes difficult to use in applications where the color was strict.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, an aging solution prepared by contacting a cobalt compound and an organometallic compound of Group I to III or a metal hydride compound in the presence of a conjugated diene, carbon disulfide and isothiocyanate are prepared. In the method of polymerizing butadiene in which a compound selected from the group consisting of acid phenyl and xanthogenic acid compounds is contacted, a polymer having a lower melting point than the conventional method can be polymerized, and a polymer having a narrow melting point distribution can be polymerized. The present invention provides a polymerization method that suppresses the agglomerates of the polymer and brings the color of the polymer close to white.

[0006]

SUMMARY OF THE INVENTION The present invention provides an aging solution obtained by contacting (a) a cobalt compound and (b) a Group I to III organometallic compound or a metal hydride compound in the presence of a conjugated diene. (Component A), carbon disulfide, a compound selected from the group consisting of phenyl isothiocyanate and a xanthate compound (Component B), and a catalyst consisting of a compound selected from an oxidizing agent, an acid and a chelate compound (Component C) And a method for polymerizing butadiene.

The present invention also relates to the above-mentioned method for polymerizing butadiene, wherein the oxidizing agent is oxygen or hydrogen peroxide.

The present invention also relates to the above-mentioned butadiene polymerization method, wherein the butadiene polymerization method is an aqueous suspension polymerization method.

The present invention also relates to the above-mentioned butadiene polymerization method, wherein the polybutadiene obtained by the butadiene polymerization method is a polybutadiene having a syndiotactic 1,2-structure as a main structure.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The ripening solution (component A) used in the present invention is (a) a cobalt compound and
(b) It can be prepared by contacting an organometallic compound of Group I to III or a metal hydride compound.

As the above-mentioned conjugated diene, 1,3-butadiene can be used alone, but 1,3-butadiene is the main component and other unsaturated monomers such as isoprene, chloroprene and myrcene are conjugated. Contains at least one monomer selected from dienes, olefins such as ethylene, propylene, butene-1, butene-2, isobutene and pentene-1, and / or aromatic vinyl compounds such as styrene and α-methylstyrene. You can leave. But,
It is desirable that the content of the other unsaturated monomer is generally limited to 30 mol%, particularly 70 mol%, based on the total amount of the monomers.

As the cobalt compound as the component (a), a salt or complex of cobalt is preferably used. Particularly preferred are cobalt salts such as cobalt chloride, cobalt bromide, cobalt nitrate, cobalt octylate, cobalt naphthenate, cobalt acetate and cobalt malonate, and cobalt bisacetylacetonate and trisacetylacetonate, ethyl acetoacetate. Examples thereof include triarylphosphine complexes and trialkylphosphine complexes of ester cobalt and cobalt halide, organic base complexes such as pyridine complex and picoline complex, and ethyl alcohol complex.

As the organometallic compound of Group I to III of the periodic table of the component (b), organolithium, organomagnesium, organoaluminum, etc. are usually used. Among these compounds, trialkylaluminum, dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum sesquichloride, alkylaluminum sesquibromide and the like are preferable. Of these, trialkylaluminum such as triethylaluminum, tributylaluminum and trioctylaluminum are particularly preferable.

Further, as the metal hydride compound of Group I to III, a compound that reduces a cobalt compound is preferably used. Specific examples of the metal hydride compound include lithium aluminum hydride, sodium boron hydride and lithium boron hydride.

As a method for preparing the ripening solution, it is preferable to first bring the component (a) and the component (b) into contact with each other in the presence of the conjugated diene.

The aging temperature is preferably in the range of -60 to 50 ° C.
Aging can be carried out in the absence of a solvent, but in some cases, a solvent inert to these components, for example, toluene,
It may be carried out in a solvent such as a hydrocarbon solvent such as benzene, xylene, n-hexane, mineral spirit, solvent naphtha, kerosene or a halogenated hydrocarbon solvent such as methylene chloride. Mixed aging is usually from about -60 ℃ to about 5
It can be carried out with stirring at a temperature in the range of 0 ° C, preferably about -30 ° C to about 40 ° C.

The amount of the cobalt compound used as the component (a) is usually 0.01 to 0.
The amount is preferably 00001 mol, preferably 0.00002 to 0.005 mol.

The proportion of the cobalt compound as the component (a) and the organometallic compound or the metal hydride compound of the group I to III as the component (b) is usually 0.1 to 500 (mol / mol), preferably 0.5 to 100. The range of (mol / mol) is preferable.

The component (B) of the present invention is a compound (hereinafter referred to as "carbon disulfide etc.") selected from the group consisting of carbon disulfide, phenylisothiocyanic acid and xanthogen. Among them, carbon disulfide can be preferably used. The amount of carbon disulfide added is usually 1 mol atom of cobalt atom
It is preferably in the range of 0.1 to 5000 mol, preferably 0.5 to 1000 mol.

The component (C) of the present invention is a compound selected from an oxidizing agent, an acid and a chelate compound. As the oxidant, oxygen, hydrogen peroxide, etc. are used. Oxygen, air,
Oxygen such as ozone, oxygen acid (salt), hydrogen peroxide, peroxide such as sodium peroxide, potassium permanganate,
Manganese compounds such as manganese dioxide, sodium dichromate, chromic acid related compounds such as chromium oxide, nitric acid,
Nitric acid related compounds such as dinitrogen dioxide and nitric oxide, halogens such as fluorine and chlorine, potassium peroxodisulfide,
Peracids (salts) such as peracetic acid and peroxy acid, sulfuric acids such as hot concentrated sulfuric acid and fuming sulfuric acid, oxygen acids (salts) such as bromic acid, chloric acid and perchloric acid, iron chloride, copper sulfate, copper acetate, etc. Metal oxides, oxides such as cesium oxide and copper oxide, nitrobenzene, and iodoso compounds.

As the acid, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, perchloric acid and phosphoric acid, carboxylic acid, sulfonic acid, sulfinic acid, phenol, enol, thiol,
Examples thereof include acid imides, oximes, organic acids such as sulfonamides, and the like.

Examples of the chelate include polyaminocarboxylic acids such as EDTA, oxycarboxylic acids such as citric acid, condensed phosphates, dimethylglyoxime, oxine and dithizone.

Among the above, oxygen, air, hydrogen peroxide and the like are preferably used.

Particularly, oxygen and air can be preferably used. A simple method is to add a fixed partial pressure to the gas phase of the polymerization tank and adjust the dissolved concentration by gas-liquid equilibrium. The amount of addition is usually 1 mol atom of cobalt atom based on the dissolved concentration.
It is preferably in the range of 0.001 to 5000 mol, preferably 0.1 to 100 mol.

Examples of the polymerization method of the present invention include an aqueous suspension polymerization method, a non-aqueous solvent polymerization method and a bulk polymerization method. In the present invention, a melting point modifier may be added to the polymerization system. Examples of the melting point adjusting agent include alcohols, aldehydes, ketones, esters, nitriles, sulfoxides, amides and phosphoric acid esters. These compounds may have only one functional group or may have two or more functional groups.

In the aqueous suspension polymerization, an inorganic salt such as calcium chloride, a dispersant such as polyvinyl alcohol and, if necessary, a surfactant dissolved or dispersed in water are usually used in suspension polymerization. What is done can be used. The ratio of the dispersant is 0.01 with respect to 100 parts by weight of water.
A range of 1 to 1 part by weight is preferred. The ratio of water is 1,3-
It is preferably in the range of 1 to 30 mol per mol of butadiene.

Further, an inert organic solvent having a high specific gravity of 1.1 (20 ° C.) or more may be added for polymerization. Specific gravity 1.1 (20
(° C) or higher, as an inert organic solvent having high specific gravity, for example, methylene chloride, carbon tetrachloride, chloroform, bromoform, halogenated aliphatic hydrocarbons such as trichlene, chlorobenzene, bromobenzene, chlorotoluene, dichlorobenzene, dibromobenzene, Hexachlorobenzene,
Halogenated aromatic hydrocarbons such as hexafluorobenzene, halogenated phenols such as chlorophenol, bromophenol, pentachlorophenol, pentabromophenol, sulfoxides such as dimethyl sulfoxide, sulfuric acid diesters such as dimethylsulfate and diethylsulfate, etc. Is preferably used.

Of these, halogenated hydrocarbons such as methylene chloride are particularly preferable because they have almost no effect of lowering the melting point of SPB.

The conjugated diene can be suspended in the polymerization medium in advance. The conjugated diene suspended in the polymerization medium may be the same as or different from that used to prepare the catalyst aging solution.

Next, in the polymerization medium of the polymerization tank, (A),
The components (B) and (C) are added to an aqueous medium to initiate polymerization. The addition order of each component is arbitrary, but after dispersing carbon disulfide or the like of the component (B) in the polymerization system, a method of initiating the polymerization by adding the ripening liquid obtained in the aging step of the component (A) is used. It is suitable.

The component (C) is added before the start of the polymerization or during the polymerization.

The polymerization temperature is preferably in the range of 0 to 100 ° C., 1
The range of 0 to 50 ° C is particularly preferable. The polymerization time is preferably in the range of 10 minutes to 12 hours, particularly preferably 30 minutes to 6 hours. The polymerization pressure is atmospheric pressure or pressure up to about 10 atm (gauge pressure).

After the polymerization is carried out for a predetermined time, the pressure inside the polymerization tank is released if necessary, and the contents are filtered to separate the dispersion medium and the produced polybutadiene particles. If necessary, the polybutadiene particles are sent to a post-treatment step such as a drying step.

[0034]

According to the method of the present invention, a polymer having a melting point lower than that of the conventional method and a polymer having a narrow melting point distribution can be polymerized, and further, a lump component produced during the polymerization can be reduced to make the color of the polymer close to white. It is provided.

[0035]

EXAMPLES (Measuring method) (Melting point) The melting point (Tm) of the conjugated diene polymer was determined from the DSC chart, and the temperature corresponding to the endothermic peak was taken as the melting point. As the DSC, SSC 5200 manufactured by Seiko Denshi Kogyo Co., Ltd. was used.
t-heatinng) Hold for 5 minutes, then 30 at 5 ℃ / min
The temperature was lowered to ℃ and kept for 5 minutes. Next, the temperature was raised to 250 ° C. under the condition of 10 ° C./min (2nd-heating). The measurement was performed under a nitrogen atmosphere. 2nd-heatin as melting point
The peak value of g was used.

(Syndio Content) The content of syndiotactic 1,2-structure in each 1,2-polybutadiene component in the polybutadiene compositions obtained in Experimental Examples and Comparative Examples was measured as follows. did. First, for each of the 1,2-polybutadiene components having different melting points, ¹ H
-NMR was measured, and the content of the 1,2-structure was determined from the peak area. Moreover, it was confirmed by ¹³ C-NMR that most of the 1,2-structures were syndiotactic structures. This graph was plotted and used as a calibration curve. ¹ H
-NMR and ¹³ C-NMR were measured using a JEOL Ltd. FX-200 model, and o-dichlorobenzene was used as the solvent, and the measurement was carried out according to the TMS standard.

(Tensile test yield stress) JIS K625
Sample cut with dumbbell-shaped No. 3 of No. 1 is marked with 2.00
cm, and a tensile test was performed at a tensile speed of 500 mm ± 50 mm / min. (Crystallinity) The sample was preheated at a temperature of 200 ° C for 5 minutes, kept at a pressure of 10 MPa for 2 minutes, and then rapidly cooled to a thickness of 1 m.
m sheet. The density of the molded sample was measured with a density gradient tube. The crystallinity was calculated using the following calculation formula. _{1 / d = χ / d c} + (1-χ) / d a d: density of the sample _{d c:} density of 100% crystalline of 1,2-PB (0.963 using) d _a: Crystallinity Density of 0% 1,2-PB (using 0.889) χ: Crystallinity of sample

Examples 1 to 10 (1) Preparation of aging liquid Butadiene 2 was added to a 1 L autoclave aging tank in which nitrogen was replaced.
Inject 40 ml (7.2 mol). 0.9 mmol cobalt octoate and triethylaluminum 2.
7 mmol was added and stirred for 20 minutes.

(2) Polymerization Nitrogen-substituted 1.5 L autoclave polymerization tank was charged with 400 ml of deionized water, 0.4 g of polyvinyl alcohol, a predetermined amount of acetone and 2.4 mmol of carbon disulfide. Then, oxygen was added at a predetermined pressure (or a predetermined compound was added at a predetermined amount), and the temperature was set to 10 ° C. with stirring. (1)
After adding 90 ml of the aging liquid adjusted in step 1 to the autoclave, the temperature of the polymerization liquid was adjusted to 20 ° C. Then, the aging liquid was continuously added so that the temperature of the polymerization liquid was kept at 20 ° C.
After the addition of the aging liquid was completed, the mixture was stirred for 30 minutes. After the polymerization, unreacted monomers were released, filtered through a paper filter, and dried to obtain SPB. The SPB yield and melting point were measured. The conditions and results are shown in Tables 2 and 3.

Comparative Examples 1 to 4 The same operations as in Examples were carried out except that no acid, oxidizing agent or chelate was added. The conditions and results are shown in Table 1.

SPB polymerized by the method of the present invention (Examples 1 to 1)
In 10), the melting point distribution was narrower and the amount of low melting point substances was smaller than that of SPB having the same melting point in Comparative Examples 1 to 4 (FIG. 1).
Further, when compared at the same melting point, S obtained by the method of the present invention
PB had a large syndio content and a large yield stress in the tensile test. Furthermore, according to the method of the present invention,
A polymer having a melting point of about 120 ° C, which could not be polymerized by the conventional method, could be polymerized. Furthermore, the lump component generated during the polymerization was reduced, and the color of the polymer was close to white.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[Brief description of drawings]

FIG. 1 is a DSC chart of SPB of Example 1.

FIG. 2 is a DSC chart of SPB of Comparative Example 2.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroaki Chakihara             No. 8 Ube Ko, No. 8 Goi Minami Coast, Ichihara City, Chiba Prefecture             Sanba Co., Ltd. Chiba Petrochemical Factory F-term (reference) 4J128 AA01 AB00 AC47 BA01A                       BA01B BB00A BB00B BB01A                       BB01B BC01A BC01B BC05A                       BC05B BC15A BC15B BC16A                       BC16B BC19A BC19B CA04C                       CA05C CA13C CA24C CA34C                       CA41C CA44C CA49C CA54C                       CB54C CB81C EB02 EB04                       EB05 EB06 EB08 EB13 EB14                       EC01 EC02 FA03 GA12 GA18                       GA19

Claims (4)

[Claims] 1. An aging liquid (component A) obtained by bringing (a) a cobalt compound and (b) an organometallic compound or a metal hydride compound of Group I to III into contact with each other in the presence of a conjugated diene,
A compound (component B) selected from the group consisting of carbon disulfide, phenyl isothiocyanate and a xanthate compound,
And a method for polymerizing butadiene, which comprises using a catalyst composed of a compound (component C) selected from an oxidizing agent, an acid and a chelate compound. 2. The method for polymerizing butadiene according to claim 1, wherein the oxidizing agent is oxygen or hydrogen peroxide. 3. The method for polymerizing butadiene according to claim 1, wherein the method for polymerizing butadiene is an aqueous suspension polymerization method. 4. The method for polymerizing butadiene according to claim 1, wherein the polybutadiene obtained by the method for polymerizing butadiene is polybutadiene having a syndiotactic 1,2-structure as a main structure.