JPS59196307A - Production of conjugated diene polymer - Google Patents

Abstract

PURPOSE:The titled high-cis 1,4 bond content polymer ecellent in vulcanization property, by polymerizing a conjugated diene with the aid of a catalyst comprising a rare earth element salt of rosin acid and specified two Al compounds. CONSTITUTION:A high-cis 1,4 bond content conjugated diene polymer of excellent vulcanization property is produced by polymerizing a conjugated diene with the aid of a catalyst comprising (A) a lanthanoid rare earth element salt of (disproportionated) rosin acid, (B) an organoaluminum compound of formula I ( wherein R<1>, R<2>, and R<3> are each H or a 1-8C hydrocarbon with the proviso that they are all not hydrogen at the same time (e.g., trimethylaluminum), and (C) a halogenated (alkyl)aluminum compound of formula II (wherein X is Cl, I, or Br, R<4> is a 1-8C alkyl, cycloalkyl, aryl, or aralkyl, and n is 1, 1.5, 2, or 3), e.g., dimethyl-aluminum chloride.

Description

[Detailed description of the invention] The present invention relates to a novel method for producing a conjugated diene polymer.

More specifically, a conjugated diene is polymerized using a catalyst consisting of a lanthanum-based rare earth salt of rosin acid or a disproportionated rosin acid, an organoaluminum compound, and an (alkyl)aluminum halide compound to obtain excellent vulcanizate properties. '1. The present invention relates to a method for producing a conjugated diene polymer having a high amount of cis-1,4-bonded gold.

The applicant has already disclosed in JP-A-58-1709 a method for polymerizing a conjugated diene using a catalyst consisting of a lanthanum-based rare earth salt of a carboxylic acid, an organoaluminum compound, and an (alkyl)aluminum halide compound. However, among the lanthanum-based rare earth salts of carboxylic acids, lanthanum-based rare earth salts of rosin acid or disproportionated rosin acid are highly active in the polymerization of conjugated dienes, and can be polymerized without requiring special considerations as working conditions. It is characterized by

Regarding conjugated diene polymerization catalysts containing rare earth elements, see Journal Polymer Science (188) 3345, (19
80) Nd salt of naphthenic acid.

Ajh (C2H3)3 Cjh and An (is
Polymerization of isoprene by o-C4Hg) 3.

NdCβ3 and C2H50H and AI! , (C2H5
) The polymerization of isoprene and butadiene by 3VC has been reported.

However, Nd naphthenate and NdCl3
Because it is only slightly soluble in hydrocarbon solvents, the polymerization activity of all of these catalyst systems is extremely low.

Furthermore, it is difficult to supply an appropriate amount of catalyst to the reaction system. In order to improve this, we will introduce the following points. Among the methods proposed so far, there is a method disclosed in Japanese Patent Laid-Open No. 12189/1983. The method uses Nd salt of carboxylic acid,
In addition to the entire Aft (C2H5)3 reaction system, the reaction product is used as a catalyst, both of which are soluble in hydrocarbon solvents, and the reaction product has high activity for the polymerization of conjugated dienes. It has been reported that However, all of these compounds have the disadvantage that they easily react with trace amounts of moisture or oxygen in the solvent, resulting in a significant decrease in the double polymerization activity. Therefore, polymerization using this method requires special consideration in handling the components, and must be carried out under many restrictive conditions for industrialization.

The inventors have developed the method of the present invention as a result of intensive studies on catalysts that have no restrictions on reaction conditions and have high activity. The method for producing a conjugated diene polymer according to the present invention is characterized in that a solution obtained by reacting the three components shown in (5) to (C) below is used as a catalyst.

That is.

(5) A rare earth salt of rosin acid or disproportionated rosin acid≠ (in the formula I (1, IP, R" each represents the same or different group, hydrogen or a hydrocarbon having 1 to 8 carbon atoms) Group 8 such as an alkyl group, a cycloalkyl group, an aryl group,
(C) AIXnR'(3-n) fL
RuhaO'7'7 (alkyl/l/)aluminum compound (in the formula, , or aralkyl group; n1
d1. This is a method of polymerizing a conjugated diene using a catalyst consisting of three components (i5° represents a number n selected from 2 and 3).

The rare earth specified in (5) is a lanthanum-based rare earth element with an atomic number of 57 to 71, and among these, cerium, praseodymium, neodymium, and gadolinium are preferable.
In particular, neodymium is easily available.

Most desirable due to ease of handling. These rare earth elements may be a mixture of two or more.

Rosin acid is a type of natural resin called hard pine resin, and includes abietic acid, neoabiedic acid, dihydroapiedic acid, tetrahydroabietic acid, dehydroabietic acid,
Contains ingredients such as lepopimaric acid, dextrobimaric acid, and indequinutrobimaric acid. Further, disproportionated rosin acid refers to partially hydrogenated rosin acid.

Each component of these rosin acids or disproportionated rosin acids can be used alone or in the form of a mixed acid.

It is more preferable to use dihydroabietic acid, dehydroabiedic acid, and tetrahydroabietic acid, which are not conjugated double bond type acids, alone or in a mixed acid containing these as main components.

Examples of nicum compounds include trimethylaluminum,
Triethylaluminum, tri-n-propylaluminum, tri-iso-furobylaluminum, tri-n-butylaluminum, tri-1so-butylaluminum, trihequinylaluminum, tricyclohexylaluminum, trioctylaluminum, diethylaluminum hydride, diisobutylaluminum hydride and mixtures of two or more of these.

Among these, triethylaluminum, triisobutylaluminum, and diisobutylaluminum hydride are preferred.

Further, in the halogenated (alkyl)aluminum compound represented by (AI! defined in q, Bromide, G-n
-Propylaluminum chloride, di-n-butylaluminum chloride, di-1so-butylaluminum chloride, methylaluminum di-chloride, ethylaluminum di-chloride, 1so-butylaluminum di-chloride, sesquimethylaluminum chloride, sesquietheraluminum chloride, sesqui-1so-butylaluminum chloride,
Examples include aluminum trichloride, aluminum tribromide, and mixtures thereof.

Each of these compounds (5), (B), and (C) is a hydrocarbon solvent, t-hentane, impentane, n-hexane, cyclohexane, n-hebutane, and benzene.

A catalyst component is obtained by reacting in toluene and a mixture thereof. It is sufficient for the reaction to take place at 30-70°C for 10-60 minutes. The reaction product is used as a catalyst solution without separation.

The composition ratio of the catalyst component (5) and the organoaluminum compound (B) is 1:2 to 1:300 in molar ratio. Preferably 1:2
0-1:150.

Further, the composition ratio of the catalyst component (5) and the halogenated (alkyl) aluminum compound C) is 05 to 1:10 in terms of molar ratio.
．． Preferably it is 1:1 to 1:5.

Conjugated dienes that can be polymerized with the catalyst of the present invention are isoprene, 1
．． 3-butadiene, 1,3-pentadiene, etc.
A mixture of two or more types may be used.

These conjugated dienes are per mole of catalyst component (8)]
,, 000 to 500,000 moles, preferably 5,00
It can be polymerized in a proportion of 0 to 100.000 moles.

The polymerization reaction is carried out in a hydrocarbon solvent such as n-pentane, isopentane, n-hexane, cyclohexane, n-hebutane, benozene, toluene, or a mixture thereof. Polymerization can also be carried out without using a cooled solvent. can. The polymerization temperature is -30°C to 150°C, preferably 10°C to 12°C.
The temperature is preferably in the range of 0°C, more preferably 40°C to 100°C.

The polymerization reaction may be carried out batchwise or continuously.

In the polymerization reaction, after reaching a predetermined polymerization rate, a reaction terminator is added to stop the reaction, and the solvent is removed and dried by a conventional method to produce a conjugated diene polymer.

The conjugated diene polymer of the present invention contains 90% or more of cis 1.4 and has excellent green strength, tackiness, and processability, and the vulcanized product has excellent rebound resilience and flex crack resistance, so it can be used as a general-purpose synthetic rubber for tires, belts, etc. .

It can be used as a rubber material for sheet industry and other uses.

The features of the present invention can be summarized as follows.

(a) The lanthanum series rare earth salt of rosin acid used in the present invention (catalyst component (a)) is soluble in hydrocarbon solvents and inert to moisture and oxygen, so it is easy to handle. , no special technology is required.

(b) The catalyst used in the present invention has high conjugated diene polymerization activity.

Next, examples of the present invention will be shown, but the present invention is not limited to these examples.

Example 1 The neodymium salt of tridehydroabietic acid i, 2 was added to a dried 200 m 13 flask under nitrogen gas.
IJ mol was added to the mixture, and then 50% of cyclohexane was added. Then, the mixture was stirred for 30 minutes at room temperature using a magnetic nutrer. The neodymium salt of triabietic acid was completely dissolved.

Next, add 60 mmol of triethylaluminum as a 2 mol/λ solution in cyclohexane and 3 mol of diethyl aluminum chloride as a 1 mol/p solution in cyclohexane.
Millimoles of each were added. The total amount is 120 with cyclohexane.
After diluting to a volume of ml, the mixture was reacted at 50° C. for 30 minutes to obtain a catalyst solution.

Separately, cyclo-xane 5 and 1,3-butadiene were charged into a stainless steel reactor having an internal volume of 102 mm and equipped with a stirrer and a temperature control device, and the temperature was brought to 60°C. To this was added 1 OOm, 1 of catalyst solution, and a polymerization reaction was carried out at 60° C. for 3 hours. The polymerization conversion rate was 94%. 2 as a stabilizer
．． After adding 6-di-tert-butyl cresol and removing cyclohexane and unreacted butadiene by steam distillation, vacuum drying was performed at 50° C. for 6 hours to obtain a polymer.

The microstructure of this polybutadiene is cis 1.4-935
%. Transformer 1.4 = 4.8%, 1.2 = 1.7%
Met. Mooney viscosity (MLl+4.t Oo℃)
was 700.

Example 2 Instead of neodymium salt of tridehydroabietic acid,
The same procedure as in Example 1 was carried out except that neodymium salt of tridehydroabietic acid was used. Polymerization conversion rate is 93
%Met. The microstructure of the shredded polymer is 1.
．． ．． 4 = 93.2%, trans i, 4 = 5
．． 1%, and 1. , 2 = 1.7.

Mooney viscosity (MLl+4.100°C) was 65.0.

Comparative Example 1 Caprylic acid neodymium salt Nd (C,H,5COO
) 12 mmol of a was added, and then 50 ml of cyclochitin was added. The mixture was stirred using a magnetic stirrer for 90 minutes. The neodymium salt of tricaprylic acid was not dissolved in cyclohexane and only swelled. Separately, 60 mmol of triethylaluminum was added as a 2 mol/λ solution in cyclohexane, and 3 mmol of diethylaluminium chloride was added as a 1 mol/2 solution in cyclohexane. After diluting with cyclohexane to a total volume of 120ml VC, the mixture was reacted at 50°C for 30 minutes.

The catalyst solution obtained in this way was obtained, and 1.3
Polymerization of butadiene was carried out at 60° C. for 3 hours. The polymerization conversion rate was 57%. Microstructure is Sinu 1.4-92
．． 1%, transformer 1.4 = 5.9%1, 2 = 2
．． It was 0%. Mooney viscosity (MLl+4゜ioo℃
) was 620.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Scope of Claims] <1) A lanthanum series rare earth salt of rosin acid or disproportionated rosin acid; a compound (in the formula, R1, R2 and 1 and 3 are each the same or different, and hydrogen or carbon number 1 ~8 hydrocarbon groups, all of which do not take up hydrogen at the same time); (represented by CI A fl
is chlorine, iodine or bromine; R4 is a hydrocarbon group having 1 to 8 carbon atoms: n is 1.1.5.2'! or 3) A method for producing a conjugated diene polymer, comprising polymerizing a conjugated diene using a catalyst consisting of the three components (A), (B), and (q).