JPS6216201B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new polybutadiene and a method for producing the same. The copolymer obtained by adding polybutadiene to styrene monomer and performing a radical polymerization reaction has not only the excellent properties of polystyrene but also improved impact resistance, so it is widely sold as an impact-resistant polystyrene resin. . Such impact-resistant polystyrene resins are used, for example, in frames for electrical appliances such as televisions and radios, trays for fresh sweets and fresh fish, and miscellaneous goods. In order to further improve the impact resistance of the above-mentioned impact-resistant polystyrene resin, various studies have been conducted on the molecular structure of polybutadiene. Polybutadiene is generally produced by polymerizing 1,3-butadiene, and based on the polymerization mode, it is either polymerized at the 1, 2 or 1, 4 positions. Therefore, in the molecular chain of the polybutadiene produced, bonding parts produced by polymerization at the 1 and 4 positions (1,4 structure) and those produced by polymerization at the 1 and 2 positions (1,2 structure) coexist. I will do it. The 1,4 structure is a bond that leaves one of the vinyl groups of 1,3-butadiene in the main chain of the molecule, and is therefore further divided into two types: cis structure and trans structure. On the other hand, the 1,2 structure has a vinyl group as a side chain. The polybutadiene used to produce the above-mentioned impact-resistant polystyrene resin is generally obtained by polymerizing 1,3-butadiene using an alkyl lithium as a catalyst and has a cis-1,4 structure content of 30 to 35%. , trans-1,4 structure content is 50
~60%, polybutadiene with a 1,2 structure content of 10 to 20% (low cis polybutadiene) and a cis-1,4 structure content obtained by polymerizing 1,3-butadiene with a cobalt or nickel catalyst. 96-98%, trans-1,4 structure content 1-
2%, and polybutadiene (high cis polybutadiene) with a 1,2 structure content of 1 to 2%. Since the above-mentioned low-cis polybutadiene has a high glass transition point (usually -70°C), the impact-resistant polystyrene resin obtained using this low-cis form is not fully satisfactory in terms of impact resistance. In addition, since low-cis polybutadiene is a linear polymer with a low degree of branching, it has a high solution viscosity when dissolved in styrene monomer, making it undesirable in terms of stirring when industrially producing high-impact polystyrene resin. It has the disadvantage of low productivity. On the other hand, the above-mentioned high-cis polybutadiene has a low 1,2 structure content of 1 to 2%, so its reactivity with styrene monomers (graft reactivity) is low, and impact-resistant polystyrenes obtained using high-cis polybutadiene Resins also have the drawback of not being fully satisfactory in terms of impact resistance. In order to solve these drawbacks of the conventional technology, we developed a high-cis isomer with a cis-1,4 structure content of about 80% or more and a high content of 1,2 structures (i.e., a high content of 1,2 structures in the side chain). Various attempts have been made to develop polybutadiene (with a high proportion of vinyl groups present), but none has been fully satisfactory. However, recently, various studies have been made on catalyst systems for polymerization reactions, and for example, as seen in the specification of JP-A-55-129403, a catalyst system consisting of a cobalt compound, an organoaluminium compound, water, and phosphite has been developed. There is also a known method for producing polybutadiene having a relatively high content of both cis-1,4 and 1,2 structures by carrying out a polymerization reaction of 1,3-butadiene. The present invention provides a polybutadiene having more excellent properties than the above-mentioned known polybutadiene, and the polybutadiene of the present invention has a 1,2 structure content of 4 to 20% (preferably 4 to 20%).
15%), cis-1,4 structure content 78-96% (preferably 85-96%), trans-1,4 structure content 2% or less, intrinsic viscosity [η] (toluene, 30°C)
is 0.5 to 5 (preferably 0.7 to 5), and in the nuclear magnetic resonance (NMR) spectrum of ¹³ C, there is a peak (δ value, i.e., chemical Shift, 43~
The area S _R of 44) is a peak group (δ value 38
~42) is relatively larger than the area S _B (S _R /S
_B is larger than 1, preferably 1.5 or larger). That is, as mentioned above, the polybutadiene of the present invention has a high cis-1,4 structure content (high cis) suitable for producing conventionally known impact-resistant polystyrene resins, and also has a 1,2 structure content. The present invention is a polybutadiene with a high content of 1,2 structure, which has been further improved. The present invention provides a polybutadiene having a high proportion of structures dispersed within the molecular chain (random state). As mentioned above, the polybutadiene of the present invention has 1,
The two structures are mainly in a random state, that is, the side chain vinyl groups are not localized within the polybutadiene molecular chain but are relatively uniformly dispersed. When the polybutadiene of the present invention having such characteristics is polymerized with a styrene monomer to produce an impact-resistant polystyrene resin, its impact resistance is further improved compared to conventional resins. Therefore, it is particularly suitable for use in fields where particularly high impact resistance is required. 1,2 in the molecular structure of the polybutadiene of the present invention
^13C NMR shows that the structure is in a highly random state.
In the spectrum, 1,2 in a random state
It is determined from the characteristic relative ratio of the area (usually calculated from the NMR integral curve) of the peak showing the structure and the peak group showing one or two structures in the blocked state. An example of the NMR spectrum of the polybutadiene of the present invention showing its characteristics is shown in FIG. The polybutadiene of the present invention having the above characteristics can be produced by, for example, producing 1,3-butadiene in the presence of a catalyst containing a cobalt salt of an organic carboxylic acid having 6 or more carbon atoms, a dialkylaluminum monohalide, and a dihydric alcohol. It can be obtained by polymerization. Examples of the cobalt compound as a catalyst component used in the polymerization reaction of the present invention include cobalt salts of organic carboxylic acids having 6 or more carbon atoms, such as cobalt octoate, cobalt naphthenate, and cobalt benzoate. Dialkyl aluminum monohalide has the general formula AlR ₂
X is a halogen atom). Examples of the dialkyl aluminum monohalide include diethylaluminum monochloride, diethylaluminum monobromide, diisobutylaluminum monochloride, and the like. Examples of the dipolyhydric alcohol include ethylene glycol, propylene glycol, trimethylene glycol, α-butylene glycol, β-butylene glycol, and tetramethylene glycol. Cobalt salt of organic carboxylic acid having 6 or more carbon atoms,
dialkyl aluminum monohalide, and 2
1,3- using a catalyst obtained from a hydric alcohol
When polymerizing butadiene, 1,3-butadiene may be used alone as a monomer, or 50% by weight or less (preferably 20% by weight or less) of 1,3-butadiene may be used as isoprene, 1,3-butadiene, or 1,3-butadiene.
Pentadiene, 2,3-dimethyl-1,3-butadiene, etc. may be used instead. The amount of catalyst used for 1,3-butadiene polymerization is:
With respect to 1 mole of 1,3-butadiene, the cobalt salt of an organic carboxylic acid having 6 or more carbon atoms is 0.005 mmol or more, especially 0.01 mmol or more, and the dialkyl aluminum monohalide is 0.5 mmol or more, especially 1 mmol or more, Preferably, the amount of dipolyhydric alcohol is 0.005 to 0.2 mmol, especially 0.01 to 0.1 mmol. The molar ratio (Al/Co) of dialkyl aluminum monohalide to cobalt salt of an organic carboxylic acid having 6 or more carbon atoms is preferably 5 or more, particularly 15 or more, and the dihydric alcohol is preferably 15 or more to dialkyl aluminum monohalide. It is preferably used at a concentration of 0.01 to 0.5 times the mole and 0.05 to 5 mmol/l in the polymerization system. When polymerizing 1,3-butadiene, aromatic hydrocarbons such as benzene, toluene, and xylene, n-heptane, n-hexane, and n-hexane are used as polymerization solvents.
- Polymerization may be carried out in a polymerization solvent such as an aliphatic hydrocarbon such as octane, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane. The polymerization solvent and 1,3-butadiene are amines, phosphine,
Preferably, it does not contain an electron-donating organic compound (donor) such as mercaptan. Furthermore, the amount of water in the polymerization solvent is preferably 5 ppm or less. The polymerization temperature of 1,3-butadiene is preferably 5 to 80°C, particularly preferably 20 to 70°C, the polymerization pressure may be normal pressure or higher, and the polymerization time is usually 10 minutes to 10 hours. When polymerizing 1,3-butadiene, known molecular weight modifiers, such as non-conjugated dienes such as cyclooctadiene and allene, or α-olefins such as ethylene, propylene, styrene and butene-1, can be used. A known method can be applied to take out the polybutadiene rubber after the polymerization reaction is completed. For example, after the polymerization reaction is complete, a large amount of a polar solvent such as methanol, ethanol, or other alcohol that reacts with dialkyl aluminum monohalide, or water is added to the polymerization solution, or a large amount of polar solvent is added to the polymerization solution. , by adding a small amount of a polar solvent containing inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as acetic acid and benzoic acid, monoethanolamine and ammonia into the polymerization solution, and by introducing hydrogen chloride gas into the polymerization solution. , After stopping the polymerization of 3-butadiene, the polymer is precipitated by adding a precipitant such as methanol, or by flashing (by blowing in water vapor or not blowing in water to remove the solvent by evaporation), and the polymer is separated and dried. Polybutadiene can be obtained by It is preferable to add an anti-aging agent to the polybutadiene by adding the anti-aging agent to a polymerization solution after stopping the polymerization of 1,3-butadiene or to a slurry of polybutadiene. As the anti-aging agent, a non-staining anti-aging agent is used. These anti-aging agents include 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-
4-Methylphenol (BHT), styrenated phenol, 4,4'-thiobis(6-tert-butyl-3
-methylphenol), 1,1'-bis-(4-hydroxyphenyl)cyclohexane, 1-oxy-3-methyl-4-isopropylbenzene, n-
Octadecyl-3-(4'hydroxy-3',5'-di-tert-butylphenyl)propionate, 2,5-
Ditertiary amylhydroquinone, 2,5-ditertiary butylhydroquinone, 2,2'-methylenebis-
(4-methyl-6-tert-butylphenol), tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, butylated hydroxyanisole, 4,4'-butylidenebis-(3-methyl-6 -tert-butylphenol), nickel dibutyl dithiocarbamate, nickel isopropyl xanthate, tri(nonylated phenyl)
Examples include phosphite (TNP), dilauryl thio dipropionate, and distearylthio dipropionate. Anti-aging agents may be used alone or in combination of two or more. The anti-aging agent is preferably blended in a total amount of 0.001 to 5% by weight based on the polybutadiene. The polybutadiene of the present invention can be prepared, for example, by a lump method or a lump/suspension method by preparing a mixture of 2 to 25 parts by weight, preferably 2 to 20 parts by weight, of polybutadiene and 75 to 98 parts by weight, preferably 80 to 98 parts by weight of styrene. An impact-resistant polystyrene resin can be obtained by radical polymerization, preferably by bulk suspension method. Alternatively, the polybutadiene of the present invention exhibits excellent properties when blended as is with styrene-butadiene rubber (SBR) and used for tire treads. The polybutadiene of the present invention has extremely low gel content and can be easily dissolved in styrene.
The impact-resistant polystyrene resin thus produced exhibits sometimes higher impact resistance than that produced using conventionally known polybutadiene, and also has extremely excellent gloss. Next, the present invention will be explained in more detail by showing examples, comparative examples, and reference examples. Example 1 1,3 in 2000ml of benzene (containing 2ppm water)
-1,800 g of butadiene was added, and then 1.0 mmol of ethylene glycol, 12.5 mmol of diethylaluminum monochloride and 0.08 mmol of cobalt octenoate were successively added, followed by stirring at 40°C for 30 minutes to polymerize 1,3-butadiene. After the polymerization reaction was completed, 5 ml of methanol containing a small amount of 2,6-di-tert-butyl para-cresol was injected into the polymerization solution to stop the polymerization, and then the polymerization solution was washed with water.
The product is collected as a crumb using a simple coagulator device and dried at 60℃ to form polybutadiene.
Obtained 130g. This polybutadiene has a 1,2 structure content of 5.1% and a cis-1,4 structure content of 5.1%.
The trans-1,4 structure content was 1.1%, and the intrinsic viscosity [η] (toluene, 30°C, the same hereinafter) was 1.7. of the obtained polybutadiene
¹³ C NMR spectrum (solvent: deuterated chloroform (CDCl ₃ ), internal standard TMS, measurement temperature 70°C, concentration
12% by weight) is shown in FIG. Figure 1
In the NMR spectrum, the sharp peak observed at δ = approximately 43.73 is a peak indicating a 1,2 structure that forms bonds in a random state within polybutadiene, and there are many at δ (chemical shift) = approximately 38 to 42. The peak group observed in the shape of the peak group is a peak showing a 1, 2 structure forming a bond in a block state. The area of each of those peaks is
As is clear from the integral curve also shown in the figure, the former is much larger than the latter (approximately 2.5:1 in Figure 1). Add 50 g of this polybutadiene to 1 styrene at 20°C.
The resulting solution was clear. This solution was suctioned through a glass filter (3G2). Next, apply this glass filter to 100
After vacuum drying at ℃ for 30 minutes, it was weighed. When the gel content was calculated from the increase in weight of the glass filter, the gel content of polybutadiene was 0.005, which was the detection limit.
It was not observed in terms of weight %. Example 2 Benzene 950ml, 1,3-butadiene 2500g,
200 g of polybutadiene was obtained in the same manner as in Example 1, except that 1.25 mmol of ethylene glycol, 12.5 mmol of diethylaluminium monochloride and 0.13 mmol of cobalt octenoate were used.
This polybutadiene has a 1,2 structure content of 8.3
%, the cis-1,4 structure content was 90.5%, the trans-1,4 structure content was 1.2%, and the intrinsic viscosity [η] was 1.5. of the obtained polybutadiene
The NMR spectrum showed a pattern similar to the ¹³ C NMR spectrum of polybutadiene obtained in Example 1 shown in FIG. The gel content of this polybutadiene was measured in the same manner as in Example 1, but similar to the results of Example 1, substantially no gel content was observed. Comparative Example 1 Cobalt octenoate (0.05 mmol) and diethylaluminum monochloride (5.5 mmol) were used as catalysts.
mmol) and phosphite (tri(nonylated phenyl) phosphite (TNP, 0.04 mmol)), and benzene (7.9 mol; water) was used as the polymerization solvent.
1,3-
The polymerization reaction was carried out using butadiene (3.4 mol, butadiene concentration 23% in benzene). The polymerization reaction was carried out at a temperature of 20° C. at the beginning of the reaction, and after 30 minutes, the reaction temperature was increased to 55° C. for 30 minutes. Polybutadiene was obtained by carrying out the same treatment as in Example 1 in other respects.
This polybutadiene has a 1,2 structure content of 9.5
%, cis-1,4 structure content is 89.5%, trans-
The content of 1,4 structure was 1.0%, and the intrinsic viscosity [η] was 1.6. A part of the ¹³ C NMR spectrum (measured in the same manner as in Example 1) of the obtained polybutadiene is shown in FIG. Example 3 Using 7.9 mol of benzene, 3.4 mol of 1,3-butadiene, 2.5 mmol of diethylaluminum monochloride, and 0.0087 mmol of cobalt octenoate, and changing the amount of ethylene guccol, Example 1
The polymerization reaction was carried out in the same manner as above. The results obtained are shown in Table 1.

[Table] Example 4 A polymerization reaction was carried out in the same manner as in Example 3 except that ethylene glycol was used at 0.32 mmol and the amount of diethylaluminum monochloride was changed.
The results obtained are shown in Table 2.

[Table] Example 5 A polymerization reaction was carried out in the same manner as in Example 1, using 5 mol of benzene, 7.2 mol of 1,3-butadiene, 2.5 mmol of diethylaluminium monochloride, and 0.0087 mmol of cobalt octoate, and changing the amount of ethylene glycol. I did it. The results obtained are shown in Table 3.

[Table] Example 6 A polymerization reaction was carried out in the same manner as in Example 1, using 2.2 mol of benzene, 9.6 mol of 1,3-butadiene, 2.5 mmol of diethylaluminum monochloride, and 0.026 mmol of cobalt octoate, and changing the amount of ethylene glycol. I did it. The results obtained are shown in Table 4.

[Table] Example 7 Using 7.9 mol of benzene, 3.4 mol of 1,3-butadiene, 2.5 mmol of diethylaluminum monochloride, and 0.32 mmol of ethylene glycol, the amount of cobalt octenoate was changed and the polymerization temperature was adjusted.
A polymerization reaction was carried out in the same manner as in Example 1 except that the temperature was 30°C. The results obtained are shown in Table 5.

[Table] Example 8 A polymerization reaction was carried out in the same manner as in Example 7 except that the amount of ethylene glycol was 0.16 mmol and the amount of cobalt octenoate was 0.145 mmol. The obtained polybutadiene has cis-1,4
91.8%, trans-1 and 4 are 1.8%, and 1 and 2 are
The yield was 6.4%, [η] was 0.70, and the yield was 16.6 g. Example 9 A polymerization reaction was carried out in the same manner as in Example 1 using 7.9 mol of benzene, 3.4 mol of 1,3-butadiene, 0.4 mmol of propylene glycol, 2.5 mmol of diethylaluminum monochloride, and 0.0087 mmol of cobalt octenoate. The obtained polybutadiene contained 92.9% cis-1,4, 1.8% trans-1,4, 5.3% 1,2, and [η].
0.80, and the yield was 18.5g. When the gel content of each of the polybutadienes obtained in Examples 3 to 9 was measured in the same manner as in Example 1, substantially no gel content was observed in any of them. Reference example 1 1 Replace the separable flask with nitrogen gas,
Add and dissolve 570 g of styrene and 30 g (5% by weight) of polybutadiene, then 0.3 g of n-dodecyl mercaptan and n-butyl stearate.
Add 11.4g and the styrene polymerization rate is 30% at 120℃
Polymerization was carried out with stirring until the Then, the polymerization solution was mixed with 0.5% by weight polyvinyl alcohol aqueous solution 600% by weight.
ml into a 1.5 ml autoclave, add 0.93 g of benzoyl peroxide and 0.93 g of dicumyl peroxide, and heat at 100°C for 2 hours.
Polymerization was then carried out at 125°C for 3 hours and then at 140°C for 2 hours with stirring. Bead-shaped polymers were collected from the polymerization reaction mixture, washed with water, dried, and pelletized using an extruder to obtain 500 g of impact-resistant polystyrene resin. The obtained impact-resistant polystyrene resin was injection molded to prepare test pieces for measuring physical properties. The measurement results are shown in Table 6. In the table, the amount of rubber in the high-impact polystyrene resin was determined by pyrolysis gas chromatography, the melt flow index (MI) of the high-impact polystyrene was determined by ASTM D1238, and the tensile strength and elongation of the test piece were determined by ASTMD638. Gloss is JISZ8741, Izotsu impact strength is ASTM
Determined by D256.

【table】

【table】 [Brief explanation of the drawing]

FIGS. 1 and 2 are ¹³ C NMR spectra of an example of polybutadiene of the present invention and an example of polybutadiene obtained by a known method, respectively.

Claims (1)

[Claims] 1 1,2 structure content is 4 to 20%, cis-1,4
Structural content is 78-96%, trans-1,4 structural content is 2% or less, intrinsic viscosity [η] (Toluene, 30
℃) is 0.5 to 5, and in the nuclear magnetic resonance spectrum of ¹³ C, the area of the peak (δ value 43 to 44) indicating the presence of a 1,2 structure forming a bond in a random state is the same as that of a block state. 1 forming a bond,
A polybutadiene characterized in that the area is relatively larger than the area of a peak group (δ value 38 to 42) indicating the presence of a 2-structure. 2 1,3- using a catalyst system containing a cobalt salt of an organic carboxylic acid having 6 or more carbon atoms, a dialkyl aluminum monohalide, and a dihydric alcohol.
Characterized by polymerizing butadiene, with a 1,2 structure content of 4 to 20% and a cis-1,4 structure content of 4 to 20%.
78-96%, trans-1,4 structure content 2% or less, intrinsic viscosity [η] (toluene, 30℃) 0.5-5
And in the nuclear magnetic resonance spectrum of ¹³ C,
The area of the peak (δ value 43 to 44) indicating the presence of a 1,2 structure forming a bond in a random state is the peak group (δ value) indicating the presence of a 1,2 structure forming a block state bond. Method for producing polybutadiene with a relatively larger area than the value 38-42).