JPS6138202B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a soluble cobalt compound, formula AlR ₃
(In the formula, R is a hydrocarbon residue having 1 to 6 carbon atoms) and three components of an organoaluminum compound and carbon disulfide, nitriles, alcohols, aldehydes, ketones, sulfoxides,
A catalyst obtained by polymerizing 1,3-butadiene in the presence or absence of an inert organic solvent using a catalyst obtained from a fourth component which is a compound selected from the group consisting of phosphates and amides. Hydrogen chloride gas is dissolved in a polymerization reaction mixture containing polybutadiene with a melting point of 80 to 150°C, and then alcohol is gradually added to precipitate the separated polybutadiene. dissolved in hydrogen or aliphatic ether,
A process of adding ethylene glycol monoalkyl ether or alcohol to the obtained polybutadiene solution to precipitate and separate polybutadiene, and a process of dispersing polybutadiene in alcohol and then dissolving hypochlorite or chlorite. After stirring and mixing the polybutadiene dispersion,
The present invention relates to a method for purifying polybutadiene, which comprises a step of removing polybutadiene. The polybutadiene obtained by polymerizing 1,3-butadiene in the presence of the above catalyst contains a large amount of ash, and many gel-like substances are observed in molded products of this polybutadiene, and the color tone is brown to slightly brown. It is. In addition, the polybutadiene has a bad odor, which is unfavorable in terms of environmental hygiene when molding the polybutadiene. Therefore, the uses of this polybutadiene are significantly limited. The inventors of this application completed this invention as a result of intensive research to improve the above-mentioned drawbacks of polybutadiene obtained by polymerizing 1,3-butadiene in the presence of the catalyst. According to this invention, polybutadiene having a melting point of 80 to 150°C can be purified. Soluble cobalt compounds that are a component of the catalyst include those that dissolve in inert organic solvents or liquid 1,3-butadiene, such as cobalt β-diketone complexes, β-keto acid complexes, and cobalt organic carboxylic acid salts. , halogenated cobalt complexes, etc. are used, and specific examples include cobalt acetylacetonate, cobalt acetoacetic acid ethyl ester, cobalt octoate, cobalt naphthenate, cobalt benzoate, and pyridine complexes of cobalt chloride. Specific examples of organoaluminum compounds that are one component of the catalyst include trimethylaluminum, triethylaluminum, tributylaluminum,
Examples include triphenylaluminum. Nitriles, which are the fourth component of the catalyst, are those described in Japanese Patent Publication No. 47-19893, and examples of alcohols are alcohols described in Japanese Patent Application Publication No. 50-59480 and Japanese Patent Application Publication No. 50-121380. aldehydes and ketones are disclosed in Japanese Patent Application Laid-Open No. 1987-
Each of the aldehydes and ketones described in Japanese Patent No. 121379 can be used. Specific examples of sulfoxides that are the fourth component of the catalyst include dimethyl sulfoxide, diethyl sulfoxide, di-n-propyl sulfoxide, and di-n-propyl sulfoxide.
Examples include n-butyl sulfoxide, diisopentyl sulfoxide, di-n-heptyl sulfoxide, divinyl sulfoxide, diallyl sulfoxide, diphenyl sulfoxide, dibenzyl sulfoxide, and methylallyl sulfoxide. Specific examples of phosphates include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-paramethylphenyl phosphate, and the like. Specific examples of amides include N-methylformamide, N-ethylformamide, N-propylformamide, N·N-dimethylformamide,
N/N-diethylformamide, N/N-dipropylformamide, N-methylacetamide,
N/N-dimethylacetamide, N-methylformanilide, N/N-diphenylformamide,
Formanilide, propiolactam, butyrolactam, valerolactam, caprolactam, N-methylpyrrolidone, N-ethylpyrrolidone, N-phenylpyrrolidone and the like can be mentioned. Regarding the amount of each catalyst component used in the method of the present invention, the amount of cobalt compound soluble in the polymerization solvent used is 0.001 to 1 mol%, especially 0.001 to 0.5 mol%, based on the total amount of 1,3-butadiene to be polymerized. is preferable, and the amount of organoaluminum compound used is
The amount of carbon disulfide used is preferably 0.001 to 10 mol%, particularly 0.01 to 5 mol%, and the amount of carbon disulfide used is preferably 0.0005 to 2 mol%, particularly 0.005 to 1 mol%. In addition, the molar ratio (Al/Co) of the organoaluminum compound to the soluble cobalt compound is 0.1 to
30, especially 1 to 20 is preferred. Further, the amount of the fourth component of the catalyst used varies depending on the type of the fourth component, but polybutadiene having a melting point of 80 to 150° C. can be obtained depending on the amount of the fourth component used. Generally, as the amount of the fourth component used increases, the melting point of the resulting polybutadiene decreases. In this invention, the above-mentioned catalyst is used,
1.3 in the presence or absence of an inert organic solvent
- Polymerize butadiene. Inert organic solvents include n-hexane, n-
Aliphatic hydrocarbons such as heptane, alicyclic hydrocarbons such as cyclohexane and cycloheptane, aromatic hydrocarbons such as benzene and toluene, and halogenated hydrocarbons such as dichloroethane and monochlorobenzene can be used. When an inert organic solvent is not used during the polymerization reaction, 1,3-butadiene itself is used in liquid form as the polymerization solvent. In this case, it is necessary to stop the polymerization reaction so that the entire amount of 1,3-butadiene charged does not polymerize. The polymerization reaction is usually stopped when 10 to 50% by weight of the charged 1,3-butadiene has been polymerized. In this invention, hydrogen chloride gas is dissolved in a polymerization reaction mixture obtained by polymerizing 1,3-butadiene. The amount of hydrogen chloride gas to be dissolved in the polymerization reaction mixture is at least twice the mole of the total amount of the soluble cobalt compound and organoaluminium, and at most 5 g per polymerization reaction mixture. If the amount of hydrogen chloride gas dissolved in the polymerization reaction mixture is smaller than the above lower limit, the resulting polybutadiene will have a high ash content, and many gel-like substances will be observed in the molded product of this polybutadiene. Even if the amount of hydrogen chloride gas dissolved in the polymerization reaction mixture is larger than the above upper limit, the ash content in the resulting polybutadiene will not be reduced, and on the contrary, gelation of the polybutadiene will more likely occur. The temperature of the polymerization reaction mixture when hydrogen chloride gas is dissolved is preferably 0 to 60°C. If the temperature of the polymerization reaction mixture is higher than 60℃, corrosion of the reaction equipment will easily occur, and if the temperature of the polymerization reaction mixture is lower than 0℃, the polybutadiene will tend to precipitate in lumps, and the ash content of the obtained polybutadiene will increase. Become. After dissolving the hydrogen chloride gas into the polymerization reaction mixture, the polymerization reaction mixture was heated at a temperature ranging from 0 to 60℃ for 5 to 90℃.
Preferably, the mixture is stirred for a minute. Alcohol is gradually added to the polymerization reaction mixture treated with hydrogen chloride gas to precipitate polybutadiene. The alcohol to be added is not particularly limited, but aliphatic alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-butyl alcohol, are preferably used. The amount of these alcohols added may be any amount sufficient to precipitate polybutadiene from the polymerization reaction mixture, and is usually 0.6 to 2.5 per 1 polymerization reaction mixture. It is necessary to add the alcohol gradually to the polymerization reaction mixture; if the alcohol is added all at once, the polybutadiene will precipitate in chunks and the ash content of the resulting polybutadiene will increase. The polybutadiene precipitated by the addition of alcohol is separated by filtration. In this invention, (a) polybutadiene is dissolved in a halogenated aliphatic hydrocarbon or aliphatic ether, and ethylene glycol monoalkyl ether or alcohol is added to the obtained polybutadiene solution to precipitate and separate the polybutadiene. (b) The polybutadiene dispersion obtained by dispersing polybutadiene in alcohol and then dissolving hypochlorite or chlorite is stirred and mixed, and then the polybutadiene is removed. In the present invention, the step (b) may be performed after the step (a), or vice versa. Also, when polymerizing 1,3-butadiene,
When a halogenated aliphatic hydrocarbon is used as the inert organic solvent, step (a) above can be omitted. Examples of the halogenated aliphatic hydrocarbon used in the step (a) above include methylene chloride, dichloroethane, dichloroethylene, trichloroethane, and trichloroethylene. In addition, examples of aliphatic ethers include ethyl ether,
Isopropyl ether, n-propyl ether,
Examples include n-butyl ether.
The amount of these halogenated aliphatic hydrocarbons or aliphatic ethers may be sufficient to dissolve the polybutadiene, and is usually 1 to 4 per 100 g of polybutadiene. Ethylene glycol monoalkyl ether or alcohol is added to a solution in which polybutadiene is dissolved to precipitate polybutadiene. Examples of the ethylene glycol monoalkyl ether to be added include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether. Further, examples of the alcohol include aliphatic alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-butyl alcohol. The amount of these ethylene glycol monoalkyl ethers or alcohols added may be sufficient to precipitate polybutadiene from the polybutadiene solution, and is usually 1 to 4 per polybutadiene solution. Polybutadiene precipitated by addition of ethylene glycol monoalkyl ether or alcohol is separated by filtration. In the step (b), the aliphatic alcohol having 1 to 4 carbon atoms can be used as the alcohol for dispersing the polybutadiene. The amount of alcohol may be sufficient to disperse the polybutadiene, and is usually 0.3 to 1.2 per 100 g of polybutadiene. It is preferable to add an antioxidant such as 2,6-di-tert-butyl-para-cresol, β-naphthol, phenyl-β-naphthylamine, or tetramethyldiaminodiphenylmethane to the alcohol dispersion of polybutadiene. Examples of the hypochlorite include alkali metal salts or alkaline earth metal salts of hypochlorous acid, such as sodium salts, potassium salts, calcium salts, and the like. In addition, as chlorite,
Mention may be made of the abovementioned metal salts of chlorous acid.
Also, products containing these salts as main ingredients, such as bleached powder, can also be used. The amount of these hypochlorites or chlorites ranges from 0.3 to 6% by weight, in particular from 0.5 to 3% by weight of the polybutadiene to be treated.
The amount of is preferred. If the amount of hypochlorite or oxygenate is less than the above-mentioned lower limit, the resulting polybutadiene will not be sufficiently purified, and if the amount of hypochlorite or chlorite is more than the above-mentioned upper limit, the obtained polybutadiene will not be sufficiently purified. This is not preferred because it increases the amount of gel in the polybutadiene. After dispersing polybutadiene in alcohol, it is preferable to stir and mix the polybutadiene dispersion obtained by dissolving the hypochlorite or chlorite at a temperature within the range of 20 to 50°C for 1 to 3 hours. . After stirring and mixing the polybutadiene dispersion, take out the polybutadiene. In this invention, the polybutadiene obtained by the treatment in steps (a) and (b) above is suspended in alcohol or ethylene glycol monoalkyl ether, and this suspension is stirred for 3 to 30 minutes. After washing, it is preferable to remove the polybutadiene and dry it. The amount of alcohol or ethylene glycol monoalkyl ether used is usually 0.5 to 4 per 100 g of polybutadiene (based on dry polybutadiene). According to this invention, odorless polybutadiene with an ash content of 30 ppm or less is obtained, and the number of gel-like substances in the film obtained by molding this polybutadiene is 35 or less/1200 cm ² as measured by the measuring method described below. The color tone of the sheet obtained by molding this polybutadiene is colorless and transparent. Next, Examples and Comparative Examples will be shown. In the Examples and Comparative Examples, the 1/2 structure content of polybutadiene was measured by nuclear magnetic resonance spectroscopy, the melting point of polybutadiene was indicated by the peak temperature of the absorption curve measured by a self-recording differential calorimeter, and the specific content of polybutadiene was measured by nuclear magnetic resonance spectroscopy. Viscosity ([η]) was measured in tetralin at 135°C. In addition, the gel number is 2.6-Di-3-di-3-di-3-di-3-di-3-di-3-di-3-di-3-di-3 per 100 parts by weight of polybutadiene.
A composition containing 0.5 parts by weight of butyl-4-methylphenol was dissolved in benzene to prepare a 3% benzene solution of polybutadiene, and this solution was poured into a glass frame with an area of 1200 cm ² and a height of 20 mm, and the mixture was heated at room temperature. Leave it for about 15 hours to evaporate the benzene, and the thickness will be 30mm.
This is the value obtained by preparing a film of μ and measuring the number of gel-like substances with a diameter of 0.1 mm or more present per 1200 cm ² of the film. In addition, the odor of polybutadiene was determined by a twice-blinded odor sensory test conducted by a panel consisting of 15 members of the Polymer Research Institute of Ube Industries, Ltd. For each powdered polybutadiene, the degree of odor was determined from strongly odor to slightly odor.
The results are divided into three ranks (almost odorless) and the number of people judged to belong to each rank is shown. Further, the color tone of a 3 mm thick sheet formed by molding the polybutadiene composition described above using an extraction molding machine at a temperature 20° C. higher than the melting point of polybutadiene was evaluated. Example 1 A solution of 123 g of 1,3-butadiene dissolved in 777 ml of dehydrated monochlorobenzene was placed in a glass reaction vessel of Content 2 in which the air was replaced with nitrogen gas, and 0.6 mmol of carbon disulfide and 5 g of dimethylformamide were added thereto. Then, 10 mmol of 1,3-butadiene was added to 50 ml of dehydrated monochlorobenzene.
A solution containing 2 mmol of triethylaluminum and 0.4 mmol of cobalt octoate was added to
Add the ingredients aged at ℃ for 5 minutes and heat at 30℃ under stirring.
1,3-Butadiene was polymerized for 40 minutes. Thereafter, 1 g of hydrogen chloride gas was dissolved in the polymerization reaction mixture while stirring was continued, and the mixture was kept at 20° C. for 20 minutes. Then add 800% methyl alcohol to the polymerization reaction mixture.
ml was added at a rate of 20 ml/min to precipitate polybutadiene. Collect the precipitated polybutadiene, dissolve the polybutadiene in 1 part of methylene chloride, and add 1 part of methyl alcohol to the resulting solution while stirring.
The polybutadiene was precipitated by adding at an addition rate of ml/min. The precipitated polybutadiene was collected, and the polybutadiene was suspended in 1 part of methyl alcohol to uniformly disperse it, and then added with sodium hypochlorite.
After dropping 22 ml of an aqueous solution containing 0.9 g, the temperature was 20-25℃.
The mixture was stirred and mixed for 3 hours. Take the polybutadiene, and add the removed polybutadiene to methyl alcohol.
The suspension was suspended in 800 ml, stirred at 20°C for 10 minutes and washed, then the polybutadiene was removed and dried. The yield of the resulting powdered polybutadiene was 85
g, melting point is 110℃, 1/2 structure content is 80%,
[η] was 1.1. The ash content of this polybutadiene was 25 ppm. The gel number of the film molded from this polybutadiene was 20, and the color tone of the sheet molded from this polybutadiene was colorless and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 0 people said it smelled strongly, 4 people said it smelled a little, and 26 people said it hardly smelled. Comparative Example 1 Polybutadiene obtained by polymerization and hydrogen chloride gas treatment in the same manner as in Example 1 was treated with methyl alcohol.
The suspension was suspended in 800 ml, stirred at 20°C for 10 minutes, washed, and then the polybutadiene was taken out and dried to obtain 90 g of powdered polybutadiene. The melting point of this polybutadiene is 110℃, the 1/2 structure content is 80%, [η]
was 1.1, the ash content was 50 ppm, the gel number of the film molded from this polybutadiene was 22, and the color tone of the sheet molded from this polybutadiene was yellowish brown and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 28 people found it strongly smelling, 2 people found it a little smelly, and 0 people found it hardly smelled. Examples 2 to 10 The same procedure as Example 1 was carried out except that the combinations of the solvent for dissolving the polybutadiene obtained by hydrogen chloride gas treatment and the non-solvent for precipitating the polybutadiene were changed to the combinations shown in Table 1. did. Yield of the obtained powdered polybutadiene, melting point, 1/2 structure content, [η], ash content, gel number of the film formed from the obtained polybutadiene, color tone of the sheet formed from the obtained polybutadiene, Table 1 shows the results of the sensory test of the odor of the obtained polybutadiene.

【table】

[Table] Comparative Examples 2 to 3 The results were carried out in the same manner as in Example 1, except that the solvents shown in Table 2 were used instead of methylene chloride as the solvent for dissolving polybutadiene obtained by hydrogen chloride gas treatment. Shown in Table 2.

[Table] Examples 11 to 14 The same procedure as in Example 1 was carried out except that the amount of sodium hypochlorite was changed to the amount listed in Table 3. The results are shown in Table 3.

[Table] Example 15 The same procedure was carried out except that dehydrated benzene was used as an inert organic solvent for the polymerization of 1,3-butadiene instead of dehydrated monochlorobenzene, and 1.4 g of sodium chlorite was used instead of sodium hypochlorite. It was carried out in the same manner as in Example 1. The yield of the powdered polybutadiene obtained was 70
g, melting point is 106℃, 1/2 structure content is 78%,
[η] is 1.1, the ash content is 25 ppm, and the gel number of the film formed from this polymer is 30.
The color tone of the sheet molded from this polymer was colorless and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 0 people said it smelled strongly, 4 people said it smelled a little, and 26 people said it hardly smelled. Example 16 2.7g bleaching powder instead of sodium hypochlorite
Example 1 except that ethyl alcohol 1 was used in place of methyl alcohol as the alcohol for dispersing polybutadiene, and the resulting polybutadiene dispersion was stirred and mixed at 20 to 25°C for 3 hours.
It was carried out in the same way. The yield of the powdered polybutadiene obtained was 82
g, melting point is 110℃, 1/2 structure content is 80%,
[η] is 1.1, the ash content is 25 ppm, and the gel number of the film formed from this polybutadiene is 25.
The color tone of the sheet molded from this polybutadiene was colorless and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 0 people said it smelled strongly, 4 people said it smelled a little, and 26 people said it hardly smelled. Example 17 Using 60 ml of methyl alcohol as the fourth component of the catalyst instead of dimethylformamide, the amount of methyl alcohol to disperse polybutadiene was 500 ml.
The same procedure as in Example 1 was carried out except that the volume was changed to ml. The yield of the resulting powdered polybutadiene was 50
g, melting point is 130℃, 1/2 structure content is 85%,
[η] is 1.1, the ash content is 25 ppm, and the gel number of the film made from this polybutadiene is 30.
The color tone of the sheet molded from this polybutadiene was colorless and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 0 people said it smelled strongly, 4 people said it smelled a little, and 26 people said it hardly smelled. Example 18 The amount of dehydrated monochlorobenzene used starts from 777ml.
Same as Example 1 except that 350 ml of acetone was used instead of dimethylformamide as the fourth component of the catalyst, the polymerization temperature was changed to 35°C, and the amount of methyl alcohol for dispersing polybutadiene was changed to 500 ml. carried out. The yield of the powdered polybutadiene obtained was 55
g, melting point is 108℃, 1/2 structure content is 79%,
[η] is 1.0, the ash content is 25 ppm, and the gel number of the film made from this polybutadiene is 32.
The color tone of the sheet molded from this polybutadiene was colorless and transparent. The results of the sensory test for the odor of polybutadiene were as follows: 0 people said it smelled strongly, 6 people said it smelled a little, and 24 people said it had almost no odor.

Claims (1)

[Claims] 1 Soluble cobalt compound, formula AlR ₃ (wherein R
is a hydrocarbon residue having 1 to 6 carbon atoms) and carbon disulfide, as well as nitriles, alcohols, aldehydes, ketones, sulfoxides, phosphates, and amides. 1.3- in the presence or absence of an inert organic solvent using a catalyst obtained from a fourth component which is a compound selected from the group consisting of:
Obtained by polymerizing butadiene, with a melting point of 80 to 150.
After dissolving hydrogen chloride gas in a polymerization reaction mixture containing polybutadiene at ℃, alcohol is gradually added to precipitate the separated polybutadiene, and the polybutadiene is dissolved in a halogenated aliphatic hydrocarbon or aliphatic ether. , Adding ethylene glycol monoalkyl ether or alcohol to the obtained polybutadiene solution to precipitate and separate polybutadiene, and dissolving polybutadiene in alcohol and then dissolving hypochlorite or chlorite therein. 1. A method for purifying polybutadiene, which comprises stirring and mixing a polybutadiene dispersion obtained by the above steps, and then treating the resulting polybutadiene dispersion with a step of removing the polybutadiene.