JP2000212227A - 1,2-polybutadiene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a 1,2-polybutadiene as a thermoplastic elastomer which allows no generation of mold stains, thermal degradation nor change in physical properties with time at high-temperature molding and exerts excellent properties such as moldability, transparency, mechanical strength property, wet skid resistance, and a 1,2-polybutadiene which yields a vulcanized rubber having excellent properties. SOLUTION: A 1,2-butadiene has (i) a 1,2-bond content in a bond unit of butadiene of 70 wt.% or larger, (ii) a melting point within the range of from 50 to 130 deg.C, (iii) a viscosity η, measured by using a slit die rheometer at a shear rate of 5,113 sec-1, of from 400 to 1,200 poise at 120 deg.C, from 300 to 1,000 at 150 deg.C and from 200 to 800 poise at 180 deg.C and (iv) a total halogen content of 30 ppm or smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel 1,2-polybutadiene. More specifically, the present invention relates to a novel 1,2-polybutadiene used as a thermoplastic elastomer for molding various molded articles such as industrial parts and footwear, various sheets and films, and further as a vulcanizing rubber.

[0002]

2. Description of the Related Art 1,2-polybutadiene, which is controlled to have an appropriate degree of crystallinity, has a structure comprising a region rich in crystallinity and an amorphous portion. Since it has a chemically-reactive carbon-carbon double bond therein, it also has the function of a conventional vulcanized rubber or a thermosetting resin having an increased crosslinking density. Also, this 1,
Since 2-polybutadiene has excellent processability, it has been applied as a modifier for other resins and thermoplastic elastomers, and as a polymer material for medical use.

[0003] Conventionally, these 1, whose crystallinity is controlled,
2-polybutadiene is a catalyst comprising a phosphine complex of a cobalt salt, a trialkylaluminum and water (Japanese Patent Publication No. Sho 4).
4-32425), a catalyst comprising a cobalt compound, a trialkylaluminum and water, and a triphenylphosphine derivative (Japanese Patent Publication No. 61-27402). In these catalyst systems, a halogenated hydrocarbon solvent represented by methylene chloride exhibits high polymerization activity, and the polymerization activity decreases in a hydrocarbon solvent. Therefore, polymerization is carried out using a halogenated hydrocarbon solvent.

[0004] However, 1,2-polybutadiene produced using a halogenated hydrocarbon solvent contains a considerable amount of halogen such as chlorine due to the solvent remaining in the solvent. For example, hydrogen halides such as hydrogen chloride are generated, and the mold rusts, 1,2-polybutadiene undergoes thermal deterioration, and physical properties change with time.

Further, 1,2-polybutadiene is required to have more excellent properties as a thermoplastic elastomer.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to
2-Polybutadiene is improved in the problems such as mold contamination, heat deterioration and change of physical properties over time during high-temperature molding, and has excellent properties such as moldability, transparency, mechanical strength characteristics, and wet skid resistance. It is to provide 1,2-polybutadiene as a plastic elastomer. Another object of the present invention is to provide 1,2-polybutadiene from which a vulcanized rubber having excellent properties can be obtained.

[0007]

According to the present invention, the following object of the present invention is achieved by providing the following 1,2-polybutadiene. (1) (i) the 1,2 bond content in the butadiene bond unit is 70% by weight or more, and (ii) the melting point is 50 to 1.
(Iii) viscosity η measured with a slit die rheometer at a shear rate of 5113 sec ^-1.
However, at 120 ° C., it is in the range of 400 to 1200 poise, at 150 ° C., it is in the range of 300 to 1000 poise, and at 180 ° C., it is in the range of 200 to 800 poise,
(Iv) 1,2-polybutadiene having a total halogen content of 30 ppm or less.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The 1,2-polybutadiene of the present invention is obtained by polymerizing butadiene in the presence of a catalyst containing a cobalt compound and an aluminoxane.
(Iv) is satisfied.

The 1,2-polybutadiene of the present invention has a 1,2 bond content in the butadiene bond unit of 70% or more, preferably 80% or more (condition (i)). 1,
When the content of two bonds is 70% by weight or more, 1,2-polybutadiene of the present invention exhibits good properties as a thermoplastic elastomer. In addition, 1,2-
Polybutadiene has crystallinity, and its melting point is 50-1.
It is in the range of 30 ° C, preferably 60 to 120 ° C (condition (ii)). When the melting point is in this range, the result is excellent in balance between mechanical strength such as tensile strength and tear strength and flexibility.

The 1,2-polybutadiene of the present invention was subjected to a shear rate of 5113 sec by a slit die rheometer.
^The viscosity η measured at ^-1 is 400 to 400 ° C.
1,200 poise, preferably in the range of 500 to 1000 poise, and at a temperature of 150 ° C., 300 to 1,000 poise.
e, preferably in the range of 400 to 800 poise, and at a temperature of 180 ° C., 200 to 800 poise, preferably 300
６００600 poise (condition (iii)). If the viscosity η at each temperature is less than each of the above lower limit viscosities, the mechanical strength is inferior, so that it is not preferable. The method for measuring the viscosity η with a slit die rheometer is described in detail in the section of Examples.

The 1,2-polybutadiene of the present invention has a total halogen content of 30 ppm or less (condition (iv)). Usually, the amount of halogen in the polymer is measured by quantitative analysis using fluorescent X-rays. In this method, the lower limit of the measurement limit is 30 ppm. Due to such a small total halogen value remaining in the 1,2-polybutadiene of the present invention, during high-temperature molding such as injection molding, mold contamination, heat deterioration, and changes in physical properties with the passage of time. The problem is improved, the workability and the moldability are good, and the physical properties of the molded article are maintained for a long time.

In the 1,2-polybutadiene of the present invention, a small amount of a conjugated diene other than butadiene may be copolymerized.
Examples of the conjugated diene other than butadiene include 1,3-pentadiene, 1,3-butadiene derivatives substituted with a higher alkyl group, and 2-alkyl-substituted-1,3-butadiene. Among them, 1,3-butadiene derivatives substituted with higher alkyl groups include 1-pentyl-
Examples thereof include 1,3-butadiene, 1-hexyl-1,3-butadiene, 1-heptyl-1,3-butadiene, and 1-octyl 1,3-butadiene.

Representative examples of the 2-alkyl-substituted-1,3-butadiene include 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene,
2-propyl-1,3-butadiene, 2-isopropyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-isobutyl-1,3-butadiene, 2-amyl-1,3-butadiene, 2-isoamyl-1,3-butadiene, 2-hexyl-1,3-butadiene, 2-cyclohexyl-1,3-butadiene, 2-isohexyl-
1,3-butadiene, 2-heptyl-1,3-butadiene, 2-isoheptyl-1,3-butadiene, 2-octyl-1,3-butadiene, 2-isooctyl-1,3
-Butadiene and the like. Among these conjugated dienes, preferred conjugated dienes copolymerized with butadiene include isoprene and 1,3-pentadiene. The content of butadiene in the monomer component used for the polymerization is preferably at least 50 mol%, particularly preferably at least 70 mol%. If too much conjugated diene other than butadiene is copolymerized, 1,2-polybutadiene of the present invention will not satisfy the above conditions (i) to (iii).

The 1,2-polybutadiene of the present invention that satisfies the above conditions (i) to (iv) is obtained by polymerizing butadiene in the presence of a catalyst containing a cobalt compound and an aluminoxane, as described above. can get. As the cobalt compound, preferably, an organic acid salt of cobalt having 4 or more carbon atoms can be exemplified. Specific examples of the organic acid salts of cobalt include octylates such as butyrate, hexanoate, heptylate and 2-ethyl-hexyl acid, decanoates, and higher grades such as stearic acid, oleic acid and erucic acid. Examples include fatty acid salts, benzoates, tolylates, xylylates, alkyls such as ethylbenzoic acid, aralkyl, allyl-substituted benzoates and naphthoates, and alkyl, aralkyl or allyl-substituted naphthoates. Of these, the so-called octylates of 2-ethylhexylic acid, stearates, and benzoates are preferred because of their excellent solubility in hydrocarbon solvents.

Examples of the aluminoxane include those represented by the following general formula (I) or (II).

[0016]

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[0017]

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In the aluminoxane represented by the general formula (I) or (II), R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group and a butyl group, preferably a methyl group, an ethyl group. And particularly preferably a methyl group. M is an integer of 2 or more, preferably 5 or more, and more preferably 10 to 100. Specific examples of aluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, and the like.
Methylaluminoxane is particularly preferred.

It is extremely preferred that the polymerization catalyst contains a phosphine compound in addition to the above-mentioned cobalt compound and aluminoxane. The phosphine compound is a component effective for activating the polymerization catalyst, controlling the vinyl bond structure and crystallinity, and preferably includes an organic phosphorus compound represented by the following general formula (III).

[0020]

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In the general formula (III), Ar represents a group shown below.

[0022]

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(In the above groups, R ¹ , R ² and R ³ are the same or different and each have a hydrogen atom and a carbon number of preferably 1 to 1.
6 alkyl groups, halogen atoms, and preferably 1 carbon atom
And preferably 6 to 12 alkoxy groups or 6 to 12 carbon atoms.
In general formula (III), R represents a cycloalkyl group or an alkyl-substituted cycloalkyl group, and n is an integer of 0 to 3.

Specific examples of the phosphine compound represented by the general formula (III) include tri- (3-methylphenyl)
Phosphine, tri- (3-ethylphenyl) phosphine, tri- (3,5-dimethylphenyl) phosphine,
Tri- (3,4-dimethylphenyl) phosphine, tri- (3-isopropylphenyl) phosphine, tri-
(3-t-butylphenyl) phosphine, tri- (3,
5-diethylphenyl) phosphine, tri- (3-methyl-5-ethylphenyl) phosphine), tri- (3-
Phenylphenyl) phosphine, tri- (3,4,5-
Trimethylphenyl) phosphine, tri- (4-methoxy-3,5-dimethylphenyl) phosphine, tri-
(4-ethoxy-3,5-diethylphenyl) phosphine, tri- (4-butoxy-3,5-dibutylphenyl) phosphine, tri (p-methoxyphenylphosphine), tricyclohexylphosphine, dicyclohexylphenylphosphine, tribenzylphosphine , Tri (4-methylphenylphosphine), tri (4-ethylphenylphosphine) and the like. Of these, particularly preferred are triphenylphosphine, tri- (3-methylphenyl) phosphine,
Tri- (4-methoxy-3,5-dimethylphenyl) phosphine and the like.

Further, as the cobalt compound, a compound represented by the following general formula (IV) can be used.

[0026]

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The compound represented by the general formula (IV) is a complex having, as a ligand, a phosphine compound in which n is 3 in the general formula (III) with respect to cobalt chloride. When using this cobalt compound, a compound synthesized in advance may be used, or a method in which cobalt chloride and a phosphine compound are brought into contact in a polymerization system may be used. By selecting various phosphine compounds in the complex, it is possible to control the amount of 1,2 bonds and the crystallinity of the obtained 1,2-polybutadiene.

Specific examples of the cobalt compound represented by the above general formula (IV) include cobalt bis (triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3 -Ethylphenylphosphine)] dichloride, cobalt bis [tris (4-methylphenylphosphine)] dichloride, cobalt bis [tris (3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (3,4-dimethylphenylphosphine) )] Dichloride, cobalt bis [tris (3-isopropylphenylphosphine)] dichloride, cobalt bis [tris (3-t-butylphenylphosphine)] dichloride, cobalt bis [tris (3,5-diethylphenyl) Sphine)] dichloride, cobalt bis [tris (3-methyl-5-ethylphenylphosphine)] dichloride, cobalt bis [tris (3-phenylphenylphosphine)] dichloride, cobalt bis [tris (3,4,5-trimethylphenyl) Phosphine)] dichloride, cobalt bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (4-ethoxy-3,5-diethylphenylphosphine)] dichloride, cobalt bis [tris ( 4-butoxy-3,
5-dibutylphenylphosphine)] dichloride, cobalt bis [tris (4-methoxyphenylphosphine)] dichloride, cobalt bis [tris (3-methoxyphenylphosphine)] dichloride, cobalt bis [tris (4-dodecylphenylphosphine)] dichloride And cobalt bis [tris (4-ethylphenylphosphine)] dichloride.

Of these, particularly preferred are cobalt bis (triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3,3)
5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride and the like.

The amount of the catalyst used is as follows: in the case of homopolymerization of butadiene, per mole of butadiene;
Total amount of butadiene and conjugated diene other than butadiene 1
The amount of the cobalt compound per mole is 0.001 to 1 mmol, preferably 0.01 to 0.5 in terms of cobalt atom.
Use about millimoles. The amount of the phosphine compound used is determined by the ratio of the phosphorus atom to the cobalt atom (P / Co).
As 0.1 to 50, preferably 0.5 to 2
0, more preferably 1 to 20. Further, the amount of aluminoxane used is expressed as a ratio of aluminum atoms to cobalt atoms of the cobalt compound (Al / Co):
Usually, it is 4 to 10 ⁷ , preferably 10 to 10 ⁶ . When the complex represented by the general formula (IV) is used, the amount of the phosphine compound used is such that the ratio of the phosphorus atom to the cobalt atom (P / Co) is 2, and the amount of the aluminoxane is as described above. Follow the description in

Examples of the inert organic solvent used as the polymerization solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene and cumene; aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-butane; Examples include alicyclic hydrocarbon solvents such as cyclopentane, methylcyclopentane, and cyclohexane, and mixtures thereof.

The polymerization temperature is usually -50 to 120 ° C.
Preferably it is -20 to 100 ° C. The polymerization reaction may be a batch type or a continuous type. The concentration of the monomer in the solvent is usually 5 to 50% by weight, preferably 10 to 35% by weight. In addition, in order to prevent the deactivation of the catalyst and the polymer of the present invention in producing the polymer, consideration must be given to minimizing the incorporation of a compound having a deactivating effect such as oxygen, water or carbon dioxide gas into the polymerization system. is necessary. When the polymerization reaction has progressed to the desired stage, the reaction mixture is added with an alcohol, other polymerization terminators, an antioxidant, an antioxidant, an ultraviolet absorber, and the like, and then the produced polymer is separated, washed, and dried according to a conventional method. Thus, 1,2-polybutadiene of the present invention can be obtained.

The 1,2-polybutadiene of the present invention alone can provide sufficient strength even without crosslinking, and is therefore suitable for non-crosslinked molding applications such as industrial parts such as injection molding and extrusion molding and films. is there. Further, since it has excellent crosslinking reactivity, it is suitably used for a crosslinked rubber application or a reaction assistant for a vulcanizing rubber. At this time, there is no particular limitation on the processing method, and it is possible to mix by a usual resin, a roll used in rubber processing, a kneader, a Banbury mixer, a screw extruder, a melt kneading using a feeder ruder extruder, or the like. .

[0034]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited by these unless the gist of the present invention is exceeded. Unless otherwise specified, parts and percentages in Examples and Comparative Examples are on a weight basis. Various measurements in Synthesis Examples, Examples and Comparative Examples were performed by the following methods.

(1) Viscosity The viscosity was measured using a slit die rheometer whose structure is schematically shown in FIG. In other words, 2
A slit die rheometer equipped with a pressure sensor (P1, P2), a slit die, a cylinder (Barrel) pressure sensor (Pin) was used. The polymer was charged into a cylinder maintained at a predetermined temperature, and the viscosity value was measured when the polymer was extruded at a plunger speed of 5000 cm / min (at this time, the shear strain rate was 5113 sec ^-1 ). In FIG. 1, the diameter of the cylinder is 15
mm, the cross section h × M of the slit die is 1 mm × 12 m
m, the length is 54 mm, and the angle a of the hopper is 90 degrees.

(2) Content of 1,2 bonds The content of 1,2 bonds in the polybutadiene bond unit was determined by the infrared absorption spectroscopy method of D. Morero et al.
d., 41, 758 (1959)). (3) Melting point The melting point was measured using a DSC (differential scanning calorimeter) according to ASTM3.
418 was measured. (4) Crystallinity The crystallinity was determined by density measurement according to JIS K7112. At that time, the density of 1,2-polybutadiene having a crystallinity of 100% is determined by G. Natta (J. Polymer. Sci., 20, 25 (195
Using 0.963 of 6), the density of 1,2-polybutadiene having a crystallinity of 0% was confirmed to be amorphous by X-ray analysis (JP-B-44-32425, JP-B-4-3).
2426) with a density of 0.892. (5) Halogen content Measured by a fluorescent X-ray method.

(6) Thermal Stability The thermal stability was evaluated using a Labo Plastomill as a stabilization time based on a torque rise time measured under the following conditions. Here, the rise time of the torque is defined as a time indicated by an intersection with the time axis by drawing a straight line of 30 degrees with respect to the baseline at the rise portion of the torque curve. (Measurement conditions) Mixer: Capacity 100CC Blade shape Roller type Measurement temperature: 170 ° C Rotation speed: 60 rpm Filling rate: 80%

(7) Mechanical strength; tensile strength (TB), tensile elongation (EB) A molded product injection-molded under the following molding conditions was used.
It was measured according to JIS K6301. (Molding conditions) Molding machine: Inline screw type injection molding machine Mold: Flat plate of 2 × 70 × 150 mm direct gate Molding temperature: 150 ° C. Injection pressure: 660 kg / cm ² Flow control: Medium Injection: 10 seconds Cooling: 50 Second mold temperature: 30 ° C (8) Evaluation of appearance of molded product Flow mark on the surface of molded product injection-molded in (7) above,
The surface roughness, brushing, silver streak, bluing, etc. were visually observed and evaluated according to the following three grades. 〇: Excellent △: Not useless, but inferior in the above properties ×: Impossible to use

(9) Wet skid resistance; (7)
A sample having an inner diameter of 50 mm and an outer diameter of 70 mm was prepared from a molded product obtained by injection molding in the same manner as described above, and measured using a JSR type WSR tester. (Measurement conditions) Road surface: Magnetic tile completely wet with water (water amount about 180 cc)
/ Measured in minutes) Sample rotation speed: 600 rotations Contact pressure: 3 kg / cm ² Contact time: 0.02 seconds The result was indicated by A value calculated by the following formula. The larger the value, the better the wet skid resistance. A = (Torque value at the time of contact between road and sample) / (Load at contact)

(10) Parallel light transmittance: JIS K using a film formed under the following molding conditions
Measured according to 6714. (Molding conditions) Extruder: 50 mmφ extruder Screw: Shape Metering type, L / D 2
8, Compression ratio 2.0 Die: Diameter 75mmφ, Lip gap 0.7mm Extrusion temperature: 150 ° C Resin pressure: 155kg / cm2 Discharge rate: 31kg / hr Blow ratio: 4.8 Take-off speed: 15m / min Film thickness: 50 μm

(11) Moisture permeability Using a film formed in the same manner as in the above (10),
It was measured according to Z0208. (12) Gas permeability Using a film formed in the same manner as in (10) above, use AST
Carbon dioxide, oxygen and ethylene oxide transmittance were measured in accordance with MD1434. (13) Evaluation of processability and vulcanizate According to the formulation shown in Table 6, a vulcanization accelerator and a polymer excluding sulfur were kneaded in advance with a Banbury mixer at a cooling water temperature of 70 ° C for 5 minutes. Thereafter, a vulcanization accelerator and sulfur were added by a roll to obtain an unvulcanized compound. The obtained unvulcanized compound was press-vulcanized at 160 ° C. for 20 minutes to obtain a vulcanized product. The vulcanized product was evaluated according to JIS K6301. The workability was evaluated by the following two-step evaluation. 〇: Excellent in meltability, roll winding property and roll release property. ×: Poor in meltability, roll winding property, and / or roll release property.

Example 1 (Synthesis of Polymer A) Synthesis was carried out by continuous polymerization using an apparatus in which three vertical reactors equipped with a stirrer having an internal volume of 20 L were connected in series. From the vicinity of the bottom of the first reactor, a mixed solvent of cyclohexane / n-heptane (weight ratio: 80/20) was added at 270 mL / min.
43 g / min of 1,3-butadiene, 1 mL / min of a toluene solution of methylaluminoxane, and 1 mL / min of a toluene solution of cobalt bis [tris (4-methylphenylphosphine)] dichloride were fed at 40 ° C. I did it. At this time, the molar ratio of Co atom / 1,3-butadiene is 1/63000, and the atomic ratio of Al / Co is 3
8/1. The residence time (polymerization time) in the first reactor was 1 hour, and the conversion was 58%. The polymerization solution extracted from the vicinity of the top of the first reactor was supplied to the vicinity of the bottom of the second reactor, and polymerization was performed for 1 hour. In the second reactor, the conversion was 76%. Further, the polymerization solution extracted from the vicinity of the top of the second reactor was supplied to the vicinity of the bottom of the third reactor, and polymerization was performed for 1 hour. In the third reactor, the conversion is 85
%. As a terminator, 2,6-di-t was added to a pipe for conveying the polymerization solution withdrawn from the vicinity of the top of the third reactor.
The polymerization reaction was stopped by injecting a small amount of ethanol containing -butyl-p-cresol. Then, the mixture was supplied to a devolatizer (direct finishing equipment) set at 170 ° C. and 250 Torr, desolvated, and pelletized by a pelletizer to obtain a polymer A.

Example 2 (Synthesis of polymer B) Polymer B was obtained at a conversion of 85% in the same manner as in Example 1, except that the polymerization temperature was changed to 60 ° C.

Example 3 (Synthesis of Polymer C) A mixed solvent of 260 mL / min and 1,3-butadiene of 4
7.5 g / min, polymerization temperature of 80 ° C., Co atom /
The molar ratio of 1,3-butadiene is 1/73000, Al /
Polymer C was obtained at a conversion of 75% in the same manner as in Example 1 except that the atomic ratio of Co was changed to 44/1.

Example 4 (Synthesis of Polymer D) The polymerization temperature was 70 ° C., the molar ratio of Co atom / 1,3-butadiene was 1/73000, and the atomic ratio of Al / Co was 44/1.
A polymer D was obtained at a conversion of 80%, except that the above conditions were satisfied.

Example 5 (Synthesis of Polymer E) The polymerization temperature was 60 ° C., the molar ratio of Co atom / 1,3-butadiene was 1/700000, and the atomic ratio of Al / Co was 42/1.
A polymer E was obtained at a conversion of 85%.

Example 6 (Synthesis of Polymer F) The polymerization temperature was 70 ° C., the molar ratio of Co atom / 1,3-butadiene was 1/73000, and the atomic ratio of Al / Co was 44/1.
A polymer F was obtained at a conversion of 75% in the same manner as in Example 1 except that (the same conditions as in Example 4) were used.

Example 7 (Synthesis of polymer G) Polymer G was obtained at a conversion of 85% in the same manner as in Example 1 except that the polymerization temperature was 30 ° C.

Comparative Example 1 (Synthesis of Polymer H) Polymer H was obtained at a conversion of 65% in the same manner as in Example 1, except that the polymerization temperature was changed to 100 ° C.

Comparative Example 2 (Synthesis of Polymer I) Polymer I was obtained at a conversion of 85% in the same manner as in Example 1 except that the polymerization temperature was changed to 65 ° C.

Comparative Example 3 (Synthesis of Polymer J) A mixed solvent of 250 mL / min and 1,3-butadiene of 53
g / min, polymerization temperature of 60 ° C., Co atom /
The molar ratio of 1,3-butadiene is 1/700000, Al /
Polymer J was obtained at a conversion of 85% in the same manner as in Example 1 except that the atomic ratio of Co was changed to 42/1.

The viscosity data of the polymers A to J synthesized in Examples and Comparative Examples are shown in Table 1 below. Further, the 1,2 bond content (%), melting point (° C.), total halogen (chlorine) amount, crystallinity, mechanical strength, and wet skid resistance of Polymers A to J were measured. The results are shown in Tables 2 and 3 below. Further, the thermal stability of the polymers A to C synthesized in Examples 1 to 3 was measured. As a comparison, methylene chloride, which has been conventionally used as a polymerization solvent for producing 1,2-polybutadiene, was kneaded and added to the polymers A to C at 100 ppm in terms of chlorine atoms, and the effect of the halogen content on the thermal stability was confirmed. did.
The results are shown in Table 4.

[0053]

[Table 1]

[0054]

[Table 2]

*: Below detection limit (30 ppm)-: not measured

[0056]

[Table 3] *: Detection limit (30 ppm) or less /: Measurement not possible

[0057]

[Table 4] *: Detection limit (30ppm) or less

From the results shown in Tables 2 and 3, it is clear that 1,2-polybutadiene of the present invention is excellent in mechanical strength and wet skid resistance. On the other hand, the polymers of Comparative Examples 1 to 3 cannot measure the mechanical strength and the wet skid resistance, or have poor molded appearance.
Also, from the results shown in Table 4, the halogen content was 100 pp.
m, the polymer of the present invention deteriorates during kneading, the rise time of torque (stabilization time) becomes shorter,
It turns out that heat stability is inferior.

Examples 8 to 14 (Film Properties) Films were formed from the polymers A to G synthesized in Examples 1 to 7 by the method described above, and their light transmittance, moisture permeability,
The gas permeability was measured. Table 5 shows the results.

[0060]

[Table 5] -: Not measured

From the results shown in Table 5, it is found that 1,2 of the present invention
-It is clear that polybutadiene has excellent transparency and moisture permeability, and also has excellent gas permeability for oxygen and ethylene oxide.

Examples 15 to 18 and Comparative Examples 4 to 6 (vulcanization properties) Polymers A, C, E, F and Comparative Polymers H, I, J were formulated as described above in the formulation shown in Table 6. A vulcanized product was obtained by the method, and the vulcanized product was evaluated. Tables 7 and 8 show the results.
It was shown to.

[0063]

[Table 6] Accelerator DM: dibenzothiazyl disulfide Accelerator TT: tetramethylthiuram disulfide

[0064]

[Table 7]

[0065]

[Table 8]

From the results shown in Table 7, it is found that 1,2 of the present invention
-All polybutadienes could be vulcanized. In addition, a vulcanized product having high hardness and excellent strength can be obtained without a reinforcing agent, and it can be seen that the vulcanized material is suitable as a vulcanized rubber material. Further, as shown in Table 8, in Comparative Examples 4 and 5, sufficient strength was not obtained. In the case of Comparative Example 6, excellent vulcanization properties were exhibited, but in the vulcanization step, processability, particularly roll processability, was inferior and practicality was poor.

[0067]

According to the present invention, 1,2-polybutadiene of the present invention can solve the problems of mold contamination, heat deterioration and change of physical properties over time during high-temperature molding, and can improve moldability, transparency, mechanical strength characteristics, and the like. It has excellent properties such as wet skid resistance and is suitably used for applications as thermoplastic elastomers, for example, for various molded articles such as industrial parts and footwear, and for various sheets and films. The molding temperature is about 15
It is 0 ° C., which is low among thermoplastic elastomers, and is superior in energy. In addition, the 1,2-polybutadiene of the present invention is sulfur-vulcanizable and has excellent peroxide crosslinking activity and excellent filler and chemical filling properties. It can be used as a reaction aid.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a slit die rheometer.

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[Procedure amendment]

[Submission date] January 28, 1999 (1999.1.2
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction contents]

[0056]

[Table 3] *: Detection limit (30 ppm) or less /: Measurement not possible

Claims (1)

[Claims] (1) The butadiene bond unit has a 1,2 bond content of 70% by weight or more, (ii) a melting point in the range of 50 to 130 ° C., and (iii) shearing by a slit die rheometer. The viscosity η measured at a speed of 5113 sec ^{-1 is} in the range of 400-1200 poise at 120 ° C., 300-1000 poise at 150 ° C., 200-800 poise at 180 ° C., and (iv) total halogen 1,2-polybutadiene having a content of 30 ppm or less.