JPS6019323B2 - Organic polylithium polymerization initiator composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an organic polylithium polymerization initiator composition.

Organic polylithium compounds containing two or more IJ thium per molecule are industrially very useful as lithium-based initiators.

For example, when a dilithium initiator is used to polymerize a conjugated gene and then add ethylene oxide, carbon dioxide, or ethylene sulfide to obtain a terminally functional polygen, a polymer with terminals such as hydroxy, carboxy, or thiol can be obtained. , these are very useful as elastic materials. Organic polylithium initiators are also useful in obtaining teleblock polymers from conjugated genes and acrylate esters, and these teleblock polymers cannot be obtained with ordinary monolithium initiators. Furthermore, when copolymerizing a conjugated diene and a vinyl-substituted aromatic compound to obtain a teleblock polymer, if a normal monolithium initiator is used, the vinyl-substituted aromatic compound is first polymerized, and then the diene is introduced and polymerized. However, using a dilithium initiator requires only two steps, which is very advantageous for the production of industrial telefloc polymers. It is. As described above, industrially useful organic polylithium compounds are generally soluble in non-drainage solvents, and are usually used in the form of a solution using a polar solvent such as ether or tertiary amine. However, when 1,3-conjugated diene is polymerized in a system in which a large amount of polar solvent such as ether or tertiary amine is present, it is difficult to obtain a polymer with a high 1,4-structure content useful as an elastic material. In particular, it is extremely difficult to maintain a high level of 1,4 homogeneous structure of the gene moiety in a low molecular weight polymer or copolymer with both terminal functionalities which is useful as a raw material for polyurethane. In order to solve the above problem, it is possible to increase the concentration of the organic polylithium compound in the polar solvent and reduce the amount of polar solvent mixed into the polymerization system. If the concentration is too high, it becomes unstable, crystals may precipitate during storage, and the viscosity is too high, making it difficult to handle, so it is difficult to carry out the above method.

For example, when a solution of 1.4-dilithiobutane in diethyl ether reaches a concentration of 1 to 1.3 mol/more, crystals will precipitate during storage. Further, when the concentration is close to 2 mol/〆, the solution becomes very viscous and difficult to handle. Therefore, various efforts have been made to solve the above-mentioned problems.

For example, a low molecular weight organopolylithium compound (e.g. 1,4-dilithiobutane) is synthesized in a polar solvent (e.g. diethyl ether), a conjugated diene is underpolymerized in the compound solution, and an oligogen polylithium compound soluble in an incompatible solvent is synthesized. Mu (
For example, after setting Q, Yamaichi dilithiooligoptadiene),
The polar solvent is removed by distillation under reduced pressure and a non-sacrificial solvent is added (USP 3377404). After adding a high boiling point compound such as liquid paraffin to the polar solvent of oligodiene polylithium, the polar solvent is removed by distillation under reduced pressure. and then add a nonpolar solvent to form a solution (Japanese Unexamined Patent Publication No. 50-29
485) etc. However, these methods require an operation to remove the polar solvent. When the polar solvent is removed, the oligogen polylithium solidifies due to association of its ends, making it difficult to dissolve uniformly in a non-gutter solvent, and the polymerization initiator It has disadvantages for industrial use, such as the tendency to cause variations in polymerization, such as a decrease in catalyst efficiency, and the fact that the added high-boiling point compound remains in the polymer. The present inventors have conducted extensive studies on the above-mentioned problems while taking the above points into consideration. As a result, the present inventors have found that an organic polylithium compound can be produced by interposing a certain amount of conjugated diene and/or alkenyl aromatic compound in an organic polylithium compound solution. It was found that the solution was highly stabilized, and the present invention was achieved.

That is, the present invention provides an organic polylithium compound, its polar solvent or a mixed solvent of a polar solvent and a non-polar solvent, and 2×10-3 mol per mol of the organic polylithium compound.
Provided is an organic polylithium polymerization initiator composition for (co)polymerization of a conjugated diene or a conjugated diene and an alkenyl aromatic compound, which comprises l to 2×10 −1 mol of a conjugated diene and/or an alkenyl aromatic compound. It is. The polymerization initiator composition of the present invention exhibits excellent storage stability, and when it is used to polymerize a conjugated diene or copolymerize a conjugated diene and an alkenyl aromatic compound, the amount of polar solvent used is Since only a small amount is required, a polymer having a high content of 1,4-structure in the microstructure of the conjugated gene moiety can be obtained.

The organic polylithium compounds used in the present invention include 1,4-dilithiobutane, 1,5-dilithiobentane, 1,10-dilithiodecane, 1,4-dilithio-2-butene, dilithionaphthalene, dilithiomethylnaphthalene, bis(1 -lithio-3-methylbentyl)benzene, etc., conjugated dienes to be added include 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, etc., and alkenyl aromatic compounds include styrene, pinyltoluene, Q-methylstyrene, etc. There is.

Ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and anisole, and tertiary amines such as trimethylamine and dimethylaniline are used as the polar solvent. Hydrocarbon solvents such as hexane, heptane, benzene, toluene, xylene, and cyclohexane are used as the non-sacrificial solvent.

The above polar solvents, non-polar solvents, conjugated compounds, and organic polylithium compounds can be used alone or in combination of two or more.

The organic polylithium compound used in the present invention is synthesized by a conventional method such as reacting an organic polyhalogenated hydrocarbon compound with lithium in a polar solvent.

These reactions are desirably carried out at a low temperature below room temperature. After the reaction is completed, precipitates and floating substances such as excess lithium and generated lithium halide are removed to obtain a homogeneous solution of an organic polylithium compound in a polar solvent. If the concentration of lithium compounds becomes high, stability deteriorates, such as crystals precipitating during storage, so they have been used at low concentrations. However, the composition of the present invention, in which a certain amount of conjugated diene or alkenyl aromatic hydrocarbon is added to a solution of an organic polylithium compound in a polar solvent, surprisingly exhibits very good storage stability even at high concentrations. In particular, a highly concentrated polar solvent solution of an organic polylithium compound has a high viscosity, so when it is diluted with a non-magnetic solvent to make it easier to handle, the stability is lower than that of a conventional organic polylithium compound solution that does not contain conjugated genes or alkenyl aromatic compounds. It is significantly superior to . The amount of the conjugated diene or alkenyl aromatic compound added to the organic polylithium compound solution is 2 x 10-3 mol to 2 x 10-1 per 1 mol of the organic polylithium compound.
The mol is appropriate, preferably 7×10-3 to 1.5×1
0-1 mol is used, especially the use of conjugated genes such as butidene is preferred.

The amount of conjugated diene or alkenyl aromatic compound is 2×1
If it is less than 0-milk ol, the stability is insufficient and 2×
If the amount is more than 10-lmol, crystals will precipitate or the solution viscosity will increase, so it is not suitable. The conjugated diene or alkenyl aromatic compound is added to a highly concentrated polar solvent solution of an organopolylithium compound polymerization initiator at room temperature or lower than room temperature, for example, under an atmosphere of an inert gas such as nitrogen or argon.

These monomers may be added as they are or diluted with an inert solvent such as cyclohexane, either all at once or in several portions. When the organic polylithium polymerization initiator composition of the present invention is used, the content of a suitable solvent can be reduced during polymerization of a conjugated gene alone or copolymerization with an alkenyl aromatic compound in a nonpolar solvent ( (can be used as a highly concentrated solution), the 1,2-vinyl content in the microstructure of the resulting polymer can be significantly reduced compared to when conventional low concentration solutions are used.

Monomers to which the organic polylithium polymerization initiator composition of the present invention can be applied include conjugated compounds such as 1,3-ptadiene, isoprene, and 2,3-dimethylbutadiene, and in addition to these, styrene, which can be copolymerized with these, Alkenyl aromatic compounds such as Q-methylstyrene and vinyltoluene can also be used as comonomers.

When using the organic polylithium polymerization initiator composition of the present invention, hydrocarbon solvents such as hexane, heptane, benzene, toluene, and cyclohexane are preferred as the polymerization solvent.

Hydrocarbon solvents can be used alone or in combination. When (co)polymerizing the monomers using the organic polylithium polymerization initiator composition of the present invention, the solvent is usually used in an amount of 1 to 15 parts by weight per 1 part by weight of the monomer. The polymerization is carried out under an inert gas atmosphere and the reaction temperature is not particularly limited, but is usually 100 qo or less.

In particular, in a range where the degree of polymerization is 10 or less, it is desirable to polymerize at a degree of 2000 or less. The organic polylithium polymerization initiator composition of the present invention is a low molecular weight, telechelic polymer very useful as a raw material for polyurethane.
It is also very useful for the synthesis of polybutadiene glycol. That is, conventionally, in order to synthesize polybutadiene glycol with a narrow molecular weight distribution and a low content of 1,2-vinyl using a low concentration polar solution of an organic polylithium compound, first, butadiene was polymerized to a polymerization degree of 1 degree, Next, a part or all of the gutter solvent is removed, and then a predetermined amount of a non-polar solvent and butadiene, which are polymerization solvents, are added and polymerized, and after reacting with ethylene oxide, the process is treated with an aqueous mineral acid solution. was necessary. However, when the organic polylithium polymerization initiator composition of the present invention is used, there is no need to remove the gutter solvent, which is very advantageous industrially. The present invention will be described in more detail below with reference to Examples, but the present invention is not limited by these Examples unless the gist of the invention is exceeded.

In addition, in the examples, the microstructure of polybutadiene is D
．． Morero (Chim.e.lndustria
91,758 (1959)). In addition, the number of hydroxyl groups per polymer molecule was determined by dividing the number of functional groups obtained by trimethylsilylating the hydroxyl groups and measuring NMR by the number of polymers determined by a paper pressure osmometer (Tokusei Sho 49- 10
709 degrees).

Comparative Example 1 140 ml of thoroughly dehydrated and dried jelly ether was placed in a 300 ml reaction vessel equipped with a 300 ml sieve, which had been replaced with argon from which moisture and oxygen had been sufficiently removed, and then commercially available rod-shaped lithium metal 19 pieces of finely cut lithium with a shiny active surface were added.

After cooling the reaction vessel to 1,000 ℃, 63.5 g of 1,4-dichlorobutane was gradually added dropwise over 1 hour while adding Takaazusa,
Made it react. After the completion of dropping 1,4-dichlorobutane, the reaction was continued for about 2 hours to complete the reaction.

All reactions were conducted under an argon atmosphere while controlling the temperature at 100°C. After the reaction was completed, the mixture was allowed to settle down, and the produced lithium chloride was precipitated, and unreacted lithium pieces were filtered through a furnace to obtain a solution of 1,4-dilithiobutane in ethyl ether. The concentration of 1,4-dilithiobutane in the obtained solution was 2.09 hol/sleeve. This ethyl ether solution of 1,4-dilithiobutane was placed in a glass ampoule that had been sufficiently degassed and dehydrated, the ampoule was tightly stoppered, and the ampoule was stored while being kept at 6°C.

On the third day after storage, a considerable amount of transparent crystals were deposited on the walls of the ampoule container, and the concentration of 1,4-dirithiobutane in the solution at that time was 1.98 hol/sleeve. Further, on the 10th day, the precipitation of crystals was severe, and the concentration of 1,4-dilithiobutane in the solution was 1.78 hol/sol. Comparative example 2
Cyclohexane was added to the ethyl ether solution of 1,4-dilithiobutane obtained in Comparative Example 1, and 1. The shoe ol/saw diluted product was placed in a glass ampoule similar to Comparative Example 1, sealed tightly, and stored while being maintained at 6°C.

On the third day after storage, a large amount of crystals was deposited on the wall of the ampoule, and the concentration of 1,4-dirithiobutane in the ether solution at that time was 1.1 ol/ml. Example 1 In the 1,4-dilithiobutane ethylether solution of Comparative Example 1, 7×10-3 was added to 1 mol of 1,4-dilithiobutane.
Comparative Example 1 was prepared by adding mol of 1,3-butadiene.
It was stored in the same way.

Even on the 10th day after storage, no crystals were precipitated, and the concentration of 1,4-dilithioptane in the solution was 2.0 ol/filtrate, which was the same as the concentration at the start of storage. Example 2 1,3-butadiene was added to the same ethyl ether/cyclohexane mixed solvent solution of 1,4-dilithioptane as in Comparative Example 2 in Example 1.
The same amount of the same amount was added into a glass ampoule, which was sealed and stored at 6°C.

No crystal precipitation was observed even on the third day after storage, and the concentration of 1,4-dilithiobutane in the solution remained at 1.5 mol. Examples 3 to 9 and Comparative Examples 3 and 4 Ethyl ether of 1,4-dilithiobutane of Comparative Example 2
The cyclohexane mixed solvent solution was treated as shown in Table 1 and stored while being maintained at -20°C.

All experimental operations were conducted in accordance with Comparative Example 1. Table 1 Butadiene, isoprene, and styrene in amounts of 2 x 10-3 mol to 2 x 10-3 mol to 1 mol of 1,4-dilithioptane.
The 1,4-dirithiobutane solution to which 1 mol was added showed very good storage stability.

Example 10 3 substituted with argon from which oxygen and moisture were sufficiently removed
Into a reaction vessel of 0.00, 10% of the 1,4-dirithiobutane solution of Example 4 was charged, and while the reaction vessel was kept at 10 qo, 8 quarts of butadiene and 10 quarts of cyclohexane were gradually added and reacted.

Next, 140 tons of cyclohexane was added to the reaction vessel to make the reaction vessel 400 mm, and then 22 tons of butadiene was added for polymerization. Polymerization was carried out for 3 hours while maintaining the inside of the reaction vessel at 4,000 ℃. The polymerization conversion rate was 100%. Next, the inside of the reaction vessel was cooled to 100, and then 3.3 hours of ethylene oxide diluted with 15 hours of cyclohexane was introduced into the reaction vessel and reacted for 40 hours.

The resulting polymer was thoroughly soaked in 500 g of a dilute aqueous hydrochloric acid solution to remove lithium, which was a polymerization initiator residue, and then diluted with 500 g of diluted hydrochloric acid solution.
After washing three times with distilled water, the solvent was removed using a rotary evaporator, and the product was further dried at 70°C for 1 day and night. 1,2- in the microstructure of the polybutadiene moiety of the obtained polymer
The vinyl structure rate was 44.4%. Further, the number of hydroxyl groups (functionality) per polymer molecule was about 2. Comparative Example 5 By increasing the amount of diethyl ether during the synthesis of 1,4-dilithioptane in Comparative Example 1, stable 1 was obtained without adding butadiene.
,4-dirithiobutane in diethyl ether solution (1,4
- dilithiobutane concentration 1 mol/s) was obtained.

A polymer was obtained in the same manner as in Example 10, except that this 1,4-dilithiobutane ether solution 15 was used in place of the 1,4-dilithiobutane solution in Example 10. The 1,2-vinyl structural content in the microstructure of the polybutadiene portion of the obtained polymer was 56.9%, and the degree of functionality was about 2.

Claims (1)

[Claims] 1 Organic polylithium compound, its polar solvent or a mixed solvent of a polar solvent and a non-polar solvent, and 2 × 10^-^3 mol to 2 per mol of the above organic polylithium compound
An organic polylithium polymerization initiator composition for (co)polymerization of a conjugated diene or a conjugated diene and an alkenyl aromatic compound, which comprises x10^-^1 mol of a conjugated diene and/or an alkenyl aromatic compound.