JPH0311079A - Recovery of porphyrin-aluminum halogenocopmplex - Google Patents

Abstract

PURPOSE:To accomplish easy separation and recovery of the title complex without impairing its catalytic activity from a mixture of the title complex and polypropylene oxide using a chlorofluorocarbon as a selective solvent for polypropylene oxide. CONSTITUTION:A mixture of (A) a porphyrin-aluminum halogenocomplex suitable as a polymerization catalyst for propylene oxide and (B) polypropylene oxide is brought into contact with pref. 50-300 (esp. 100-200)ml per mol of said complex of a chlorofluorocarbon to selectively dissolve the component B in the chlorofluorocarbon followed by separating said complex insoluble to the chlorofluorocarbon by an established means, thus accomplishing the objective easy separation and recovery of the complex from above-mentioned mixture without impairing the catalytic activity in high recovery rate. The present complex thus recovered can be repeatedly used as said catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for recovering a porphyrin aluminum halide complex which can be suitably used as a monomer catalyst for alkylene oxides.

(Prior Art and Problems to be Solved by the Invention) Porphyrin aluminum complexes are excellent polymerization catalysts for alkylene oxides. By polymerizing alkylene oxides using a porphyrin aluminum complex, it is possible to easily obtain a polymer with a relatively large molecular weight and a small molecular weight distribution (Japanese Patent Laid-Open Nos. 61-215623 and 1988-61). 197631). Further, by coexisting an active hydrogen compound, compounds with various structures such as macromers and telechromers can be obtained.

Porphyrin aluminum complexes are functional catalysts as described above, but after polymerization, it is difficult to separate them from the resulting polymer without deactivating the catalyst activity, making it impossible to recover the catalyst sufficiently. Ta.

The above-mentioned porphyrin aluminum complex is an expensive compound because the precursor porphyrin is expensive and the yield of the synthesis reaction of the volphyrin aluminum complex using this porphyrin as a raw material is as low as 20%. . Therefore, it is desired to separate the porphyrin aluminum complex from the produced polymer, recover it, and reuse it.

(Means for Solving the Problem) The present inventors have conducted extensive research with the aim of separating and recovering l- from the produced polymer, which is a porphyrin aluminum complex. As a result, it was discovered that when the porphyrin aluminum complex is a nologeno complex, it can be easily separated and recovered from polypropylene oxide, and the present invention was completed.

That is, the present invention is characterized in that - a mixture of a porphyrin aluminum halide complex and polypropylene oxide is brought into contact with a chlorofluorocarbon, only the polypropylene oxide is dissolved in the chlorofluorocarbon, and then the porphyrin aluminum halide complex is separated. This is a method for recovering porphyrin aluminum halide complexes.

As the porphyrin aluminum logeno complex (hereinafter simply referred to as complex) in the present invention, any known compound can be used without any restriction.

A particularly suitable complex as a propylene oxide polymerization catalyst is a compound represented by the following general formula [13].

In the above formula [11], the hydrocarbon group represented by -R, to R12 preferably has a carbon number in the range of 1 to 10, and is an alkyl group.

It is generally an aryl group. R5 and R4IR
When 6 and R7+ R9 and the formula OL and R12 and R1 form a ring, the type of the ring is generally a benzene ring or a naphthalene ring. Examples of substituents for these hydrocarbon groups include halogen atoms and alkoxy groups.

Specific examples of the porphyrin aluminum halide complex used in the present invention include tetraphenylporphyrin aluminum chloride, tetrabenzporphyrin aluminum chloride, tetranaphthoporphyrin aluminum chloride, and tetraphenyltetrabenzporphyrin aluminum chloride.

Examples include tetraphenyltetranaphtoporphyrin aluminum chloride, octaethylporphyrin aluminum chloride, tetrakispentafluorophenylporphyrin aluminum chloride, tetrakistrimethoxyphenylporphyrin aluminum chloride, and the like.

On the other hand, as polypropylene oxide.

Any known material may be used without any restrictions. The degree of polymerization of the polypropylene oxide is preferably 2000 mer or less in order to improve the solubility in chlorofluorocarbons described below and to perform good separation of the porphyrin aluminum halide complex.

The mixture of porphyrin aluminum logeno complex and polypropylene oxide to be separated in the present invention may be obtained by any method, but generally, after polymerization of propylene oxide using a porphyrin aluminum complex as a catalyst, It is obtained by reacting an active rogen-containing compound.

The above porphyrin aluminum complex has the above formula CI]
This is a compound in which X represented by -.logen atom is a hydrogen atom, an alkyl group, an alkoxy group, a phenoxy group, or a hydroxyl group, and has the ability to catalyze the polymerization of propylene oxide. In the polymerization of propylene oxide using a porphyrin aluminum complex as a catalyst, when an active hydrogen compound is used as a co-catalyst along with the porphyrin aluminum complex, polypropylene oxide having this active hydrogen compound at the end or in the molecular chain can be formed. You can get it. Even in such cases, the porphyrin aluminum halide complex can be recovered by the method of the present invention, regardless of the type of active hydrogen compound used. As the active hydrogen compound used, alcohols, phenols, and carboxylic acids containing one or more hydroxyl or carboxyl groups in one molecule are effectively used. Regarding alcohols, methanol,
Aliphatic alcohols such as ethanol, furopanol, butanol; unsaturated alcohols such as allyl alcohol, 2-human 0-oxyethyl methacrylate; ethylene glycol, tripropylene glycol, trimethylolpropane.

There are aliphatic polyhydric alcohols such as pentaerythritol and glycerin. Regarding phenols, phenol,
Examples include monohydric phenols such as vinylphene/-A/ and 7lylphenol; polyhydric phenols such as resorcinol, P-dihydroxybenzene, and 2,4-toluenediol. Carbo/acids include monovalent carboxylic acids such as acetic acid, acrylic acid, and methacrylic acid; acyhinic acid, maleic acid, and fumaric acid.

Also included are polyhydric carboxylic acids such as terephthalic acid.

In addition to the active hydrogen compounds mentioned above, various alcohols, phenols, and carboxylic acids can be used effectively.

The present inventors have already discovered that fluorine-containing active hydrogen compounds are particularly effective in increasing the polymerization rate of propylene oxide, and even in this case, the recovery method of the present invention has excellent effects. demonstrate.

By the above polymerization, the aluminum atom of the porphyrin aluminum complex is bonded to one end of the molecular chain, and the -
A polypropylene oxide is obtained in which the various atoms or groups described above corresponding to XK in the formula CI) are bonded to the other end of the molecular chain. In addition, when an active hydrogen compound is used in the above polymerization, the hydrogen atom of the active hydrogen compound is bonded to one end of the molecular chain, and the residue obtained by removing the hydrogen atom from the active hydrogen compound is bonded to the end of the other molecular chain. Polypropylene oxide is obtained.

In order to separate the porphyrin aluminum complex from the molecular chain end of the polypropylene oxide thus obtained, the polypropylene oxide and the active halogen-containing compound are reacted. As a result of this reaction, the aluminum atom of the porphyrin aluminum complex and the halogen atom of the active halogen-containing compound are forcefully bonded to form a borophyrin aluminum halogen complex. On the other hand, the residue obtained by removing the halogen atom from the active halogen-containing compound is bonded to one molecular chain end of the polypropylene oxide after the porphyrin aluminum complex is separated.

Examples of the active halogen-containing compounds include methacryloyl chloride and methacryloyl bromide.

Unsaturated halogen-containing compounds such as acryloyl chloride, acryloyl bromide, allyl chloride, allyl bromide, allyl iodide, chloromethylstyrene: benzyl chloride, benzyl bromide,
Benzoyl chloride, benzoyl bromide, benzoyl fluoride.

Acetyl chloride, acetyl bromide, cetyl iodide and the like are preferably used, but the compound is not limited to the above compounds, and any compound containing an active halogen may be used without particular limitation.

In addition, especially in a polymerization system in which an active hydrogen compound is coexisting, for the purpose of synthesizing macromonomers, etc., when the residue of the above-mentioned active halogen-containing compound after removing the halogen atom is introduced into the molecular chain end of the resulting polymer. The reaction can proceed dynamically by coexisting a dehydrochlorination agent such as triethylamine or trimethylamine in one reaction system.

Furthermore, when using a dehydrochlorination agent, the solvent to be used at this time is a good solvent for the voluphyrin aluminum-Nlogeno complex and the polymer formed in one reaction, and is a good solvent for the amine hydrochloride used as the dehydrochlorination agent. A poor solvent that does not deactivate the catalytic activity of the porphyrin aluminum rhamno-10 Geno complex is used. Specifically, dehydrated and purified benzene.

Heptane, hexane, methylene chloride, diethyl ether, tetrahydrofuran, etc. are used. Furthermore, when a dehydrochlorination agent is not used, a lorofluorocarbon can also be used as described later.

The amount of the active rogen-containing compound used in the present invention is 1 to 5 times the mole of the porphyrin aluminum complex, particularly preferably 1 to 1.5 times the mole. The amount of solvent used in this reaction is preferably 50 to 5QQJ, particularly preferably 100 to 5QQJ, per mole of the porphyrin aluminum complex.
It is 2001Lt. When using a dehydrochlorination agent, the amount used is preferably at least the sum of the number of moles of the active hydrogen compound and the number of moles of the porphyrin aluminum complex.

Active...The reaction temperature with the rogen-containing compound is 0 to 50°C,
Particularly industrially, a temperature range of 10 to 30°C is suitable. The reaction time varies depending on the reaction temperature and the amount of solvent, but it takes several to several tens of hours for boat fishing.

The produced amine hydrochloride can be filtered out through a glass filter or filter paper under an inert gas atmosphere.

As described above, a mixture of a porphyrin aluminum halide complex and polypropylene oxide is obtained.

In the present invention, in order to separate the above-mentioned mixture into its respective components, the solvent in which the above-mentioned mixture is dissolved is removed if necessary, and then contact with the chlorofluorocarbon is carried out. The contacting method may be any method as long as it can dissolve the polypropylene oxide in the mixture in the chlorofluorocarbon. For example, a method of mixing the above mixture and chlorofluorocarbon, a method of flowing chlorofluorocarbon into a tower filled with the above mixture, etc. can be adopted.

As the chlorofluorocarbon, compounds commonly called fluorocarbons, in which part or all of the hydrogen atoms of chain hydrocarbons are replaced with chlorine and fluorine, can be used without limitation.

for example.

7 o y 115 T humin 112. Freon 1221
Freon 123. Freon 131. Freon 132°foy1
32b, yon 132a * Freon 133, Freon 140 a + Freon 141b.

Freon 142. Freon 151. Freon 152° Humin 1
1 Freon 21 etc. are mentioned. Among these, Freon 116, which has a high boiling point and excellent operability, is particularly preferably used.

Considering the solubility of polypropylene oxide, the amount of chlorofluorocarbon to be used is 50 to 3001 Ll per mole of porphyrin aluminum I-logeno complex.
, particularly preferably in the range of 100 to 200 d.

Also.

Contacting the above mixture with the chlorofluorocarbon is usually carried out under conditions of temperature and pressure such that the chlorofluorocarbon remains liquid. Further, it is usually sufficient to select the contact time from a range of several minutes to several tens of hours.

In this way - the polypropylene oxide can be completely dissolved in the chlorofluorocarbon and the voluphyrin aluminum complex is insoluble in the chlorofluorocarbon by known methods, for example filtration, centrifugation.

It can be recovered by separation using methods such as decantation.

(Effects) According to the method of the present invention, a porphyrin aluminum complex can be easily separated and recovered from a mixture of a porphyrin aluminum trogno complex and polypropylene oxide without impairing its catalytic activity. Therefore.

The recovered voluphyrin aluminum noherogeno complex can be repeatedly used as a polymerization catalyst for propylene oxide. For this reason, the present invention provides a method which is particularly advantageous for industrial use as a polymerization catalyst for propylene oxide, which is a voluphyrin alumino-roqueno complex.

(Examples) The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Tetraphenylporphyrin aluminum chloride complex (0-5 mmoA) and methanol (5 mmot) were placed in flask A of a reactor having nitrogen-substituted flasks A, B, and C as shown in FIG. 500 ml of propylene oxide using a syringe under air flow.
+nmot was introduced, and polymerization was carried out while stirring at room temperature for 44 hours. After the reaction was completed - a small amount of the polymer was sampled and the molecular weight and molecular weight distribution of the produced polymer was measured using gel permeation chromatography.
The number average molecular weight is 2300. The ratio (Mw/Mn) of weight average molecular weight (MY) to number average molecular weight (Mn) was 1.06. Further, the polymerization rate (conversion rate to polymer) of propylene oxide determined by gravimetric method was 73%. Then, after distilling off unreacted propylene oxide under reduced pressure,
Triethylamine (6 mmot) zmethacryloyl chloride (6 mmot) was added and reacted for 5 days in 50-n-hebutane. The triethylamine hydrochloride produced by the reaction was filtered under nitrogen, and the filtrate was collected in flask B. Thereafter, n-hebutane was distilled off under reduced pressure. Thereafter, 40 m7 of Freon 113 was added, and after stirring for 13 hours, the mixture was filtered again through a glass filter, and the filtrate was collected in flask C.

The Freon 113 solution of the polymer present in Flask C was removed with a syringe, and Freon 113 was added again with a 20-syringe to wash the porphyrin aluminum chloride complex in the system, and the washing solution was removed with a syringe. The number of collection vehicles was 90%.

Next, add 200 mmo of new propylene oxide.
t and 4.5 mmot of methanol were added to flask B and polymerized for 6 days at room temperature under nitrogen. When a small amount of the polymer was sampled and the molecular weight and molecular weight distribution were determined using gel permeation chromatography, the number average molecular weight was 10,000. The ratio of weight average molecular weight (MW) to number average molecular weight (Mn) (Mw/Mn) was 1.11. Furthermore, the polymerization rate of propylene oxide determined by gravimetric method was 70%.

Furthermore, when the structure of the polymer obtained in this example was measured by IH-NMR, a polypropylene oxide structure was confirmed.

Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that methanol was used instead of Freon 113 in Example 1.

As a result, it was not possible to separate the porphyrin aluminum chloride complex that was thought to have been formed from the polypropylene oxide. Experiments were conducted in a similar manner.

As a result, it was not possible to separate the porphyrin aluminum chloride complex from tobolypropylene oxide.

Examples 2 to 4 Experiments were conducted in the same manner as in Example 1, except that each solvent shown in Table 1 was used instead of Freon 113 as the fluorocarbon.

Table 1 shows the recovery rate of the complex, the polymerization conditions of the complex before and after recovery, and the molecular weight and molecular weight distribution of the resulting polymer.

As can be seen from Table 1, in all cases, the complex could be recovered at a high recovery rate without loss of polymerization activity.

Examples 5 to 7 Polymerization was carried out in the same manner as in Example 1 using the porphyrin aluminum complex shown in Table 2 instead of the tetraphenylporphyrin aluminum chloride complex used in Example 1 as the porphyrin aluminum complex.

Table 2 shows the recovery rate of the complex, the polymerization conditions for the complex before and after recovery, and the molecular weight and molecular weight distribution of the resulting polymer.

As can be seen from Table 2, in all cases, the complex could be recovered at a high recovery rate without losing polymerization activity.

Examples 8 to 12 The active hydrogen compounds shown in Table 6 were used instead of the methanol used in Example 1 as the active hydrogen compound, and the active hydrogen compounds shown in Table 3 were used instead of methacryloyl chloride as the active logen-containing compound.
In addition to using active logen-containing compounds shown in
All experiments were conducted in the same manner as shown in Example 1.

Table 6 shows the recovery vehicle for the porphyrin aluminum halide complex, the polymerization conditions for the complex before and after recovery, and the molecular weight and molecular weight distribution of the resulting polymer. As can be seen from Table 3, in all cases, the complex was recovered at a high recovery rate without loss of polymerization activity.

[Brief explanation of the drawing]

FIG. 1 shows the reaction apparatus used in the examples. In the figure, A, B, and C are flasks, 1 and 2 are glass filters, and 3 and 4 are three-sided pots, respectively. Diagram

Claims (1)

[Claims] (1) A porphyrin aluminum halide, which is characterized by contacting a mixture of a porphyrin aluminum halide complex and polypropylene oxide with a chlorofluorocarbon, dissolving only the polypropylene oxide in the chlorofluorocarbon, and then separating the porphyrin aluminum halide complex. Method for recovering the complex.