JPS5814413B2 - How to remove aluminum components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an aluminum component from a crude product consisting of an orthoalkylated phenol and an aluminum component obtained by reacting a phenol with an olefin in the presence of an aluminum phenoxide compound. Regarding how to remove.

Ornoalkylated phenols are useful compounds as intermediates in the production of antioxidants and agricultural chemicals.

For example, 2,6-di-t-butylphenol is 2,6-di-t-butylphenol.
t-butyl-p-cresol, 4,4'-methylenebis(2,6-di-t-butylphenol), 1,3
・5-trimethyl-2,4,6-tris(3,5-di-t-butylbenzene)benzene, tetrakis[methylene-3-(3',5'-1-di-t-butyl-4'-hydroxyphenyl) ) Propionate] is used as an intermediate in producing antioxidants such as methane, and 2-s-butylphenol is used as an intermediate in producing the agricultural chemical 2-s-butyl phenyl-N-methyl carbamate.

A known and excellent method for producing such orthoalkylated phenols is a method in which phenols and olefins are reacted using an aluminum phenoxide compound as a catalyst (Angeband Techemy, Vol. 69, 69).
9-709, 1957).

Depending on the intended ortho-alkylated phenols, the types of phenols and olefins, the molar ratio of phenols and olefins, the reaction temperature and other conditions are selected as appropriate. When about 1% by weight is dissolved, then imbutylene is added twice the mole of phenol and reacted at a temperature of 80 to 90°C under high pressure, 2.6-
75 to 85% by weight of di-tert-butylphenol, 2-
t-Butylphenol 8 to 10% by weight, 2.4.6
A homogeneous solution-like crude product is obtained consisting of -tri-tert-butylphenol and the catalyst.

However, due to the presence of a catalyst in the crude product, direct distillation of this crude product would result in a high boiling point of the above-mentioned 2-t-butylphenols;
It is necessary to heat the 2-t-butylphenol to a high temperature of between 230°C and 230°C, and as a result, the butyl group of each 2-t-butylphenol is eliminated or transalkylated from the ortho position to the para position. etc. cannot be obtained in good yield.

Such elimination or transalkylation of the alkyl group during distillation is possible for ortho-alkylated phenols, especially when the alkyl group is tertiary, as long as the catalyst is present in the crude product in an active state. occur.

Furthermore, JP-A No. 47-4416 states that if water or a solid alkali or aqueous alkali solution is added to such a crude product and then distilled, there will be no elimination or isomerization of the alkyl group. When this method is carried out on an industrial scale, aluminum components adhere to the tube walls of the reboiler used as a heating device during distillation, resulting in undesirable situations such as a decrease in heat transfer efficiency and tube clogging.

Therefore, in order to obtain orthoalkylated phenols having the intended structure from the crude product in a good yield without any process problems, it is essential to remove the aluminum component from the crude product.

As a method for removing such aluminum components, Japanese Patent Publication No. 33-7535 discloses a method in which an aluminum phenoxide type catalyst is hydrolyzed to form a solid phase of aluminum hydroxide, and a mixture of a solid phase and an oil phase is filtered. Although a method has been disclosed, aluminum hydroxide, which is a solid phase, acts as a gelling agent, and the entire mixture takes on a gel-like appearance, making it extremely difficult to separate the oil phase by filtration, and it is difficult to separate the oil phase over a long period of time. Even if the aluminum hydroxide is subjected to forced filtration, the oil phase still adheres to the aluminum hydroxide, and the amount of unrecoverable orne-alkylated phenols reaches as much as 20% by weight.

In addition, as a method to solve this situation,
-63327 proposes a method of accelerating the filtration rate by performing hydrolysis at a temperature of 165 to 250°C to generate meta-aluminate crystals, but in the inventor's follow-up experiments, the filtration time was at most 1/3 However, it was found that there was still 10% of the oil phase that could not be recovered, and that the method was completely unsuitable for industrial implementation.

On the other hand, the present inventor tried a conventional hydrolysis method, that is, adding a mineral acid such as hydrochloric acid to convert aluminum into an aqueous compound, and then separating the aqueous layer to remove the aluminum component. Although it is possible to quantitatively separate and recover ortho-alkylated phenols, mineral acids remain in the oil phase, so when ortho-alkylated phenols are separated from the oil phase by distillation, the alkyl group at the orne position is removed or transalkylated. I encountered the problem of.

Therefore, the present invention relates to a method for efficiently removing the aluminum component from the above-mentioned crude product containing an aluminum phenoxide type catalyst without loss of orne-alkylated phenols, and moreover, the removed component is distilled at high temperature. The present invention relates to a method for removing orthoalkylated phenols which does not substantially change the composition of orthoalkylated phenols contained in the product even when the product is used, and which can be carried out industrially.

That is, the present invention is a method for removing an aluminum component from a crude product consisting of an orthoalkylated phenol and an aluminum component obtained by reacting a phenol with an olefin in the presence of an aluminum phenoxide compound. , provides a method for removing an aluminum component, which comprises contacting the crude product with oxalic acid, citric acid, tartaric acid, or a mixture thereof and water to transfer the aluminum component to an aqueous phase, and then separating the aqueous layer. Concerning what to do.

According to the method of the present invention, an aqueous solution of oxalic acid, succinic acid, tartaric acid or a mixture thereof is added to the crude product, briefly stirred, and then substantially removed from the oil phase by a short oil-water separation operation. The aluminum component can be eliminated, and the orne-alkylated phenols can be recovered quantitatively in the oil phase. Moreover, even if the oil phase is distilled, there is no change in the composition, so the intended orne-alkylated phenols can be recovered quantitatively. It can be obtained in good yield.

Of course, the method of the present invention as described above can be carried out industrially very easily.

The structure and advantages of the present invention will become clearer by describing the present invention in detail below.

The crude product from which the aluminum component is removed in the present invention is obtained by reacting phenols and olefins in the presence of an aluminum phenoxide compound.

Here, the aluminum phenoxide-based compound is a compound that acts as a catalyst, and includes, for example, aluminum phenoxide, aluminum 2-methyl phenoxide, aluminum 2-t-butyl phenoxide, aluminum 2-s-butyl Among the phenoxides, aluminum phenoxide and aluminum 2-t-butyl phenoxide are preferred.

In the present invention, the olefinisos have 3 to 5 carbon atoms.
Specific examples include propylene, butene-11-butene-2, isobutylene, and isoamylene, among which propylene, butene-1,
Isobutylene is preferred.

In the present invention, examples of phenols include phenol, orthocresol, meta-cresol, para-cresol, ortho-ethylphenol, meta-ethylphenol, and para-ethylphenol, with phenol and orthocresol being preferred.

The above-mentioned aluminum phenoxide compound used in reacting the phenols with the above-mentioned olefins is usually 0.01 to 30% by weight, based on the phenols.
Preferably 0. 1 to 20% by weight is used.

The amounts of phenols and olefins used vary depending on the intended orthoalkylated phenols, but the molar ratio (olefins/phenols) is usually 0.5 to 5, preferably 1 to 3.

The reaction conditions include a temperature of 10 to 300°C, preferably 50 to 200°C, for several minutes to 10 hours, preferably 1 to 5 hours.

The crude product thus obtained is a mixture consisting of, for example, 2-alkylphenol, 2,6-dialkylphenol, 2,4,6-trialkylphenol, a small amount of unreacted phenol, and an aluminum phenoxide type compound.

In the present invention, this crude product and oxalic acid, citric acid,
Water is contacted with tartaric acid or a mixture thereof, preferably oxalic acid.

This contacting step is the most important structural requirement of the present invention.

In particular, the use of oxalic acid is inexpensive, and oil-water separation, which will be described later, is extremely easy, so very good results can be obtained.

Oxalic acid, citric acid, tartaric acid or a mixture thereof is used in an amount of 0.1 to 10 mol, preferably 0.3 to 3 mol, per mol of aluminum.

In addition, water is 0.05 to 5 parts by weight per 1 part by weight of the crude product.
Parts by weight are used, preferably 0.1 to 0.5 parts by weight.

The operation of contacting the crude product, the organic acid, and water is performed by adding the organic acid and water to a container containing the crude product, and then contacting the crude product,
Stir so that the organic acid and water come into contact.

Usually, the stirring time only takes a few minutes.

Of course, oxalic acid, citric acid, tartaric acid, or a mixture thereof and water may be made into a homogeneous aqueous solution in advance and added to the crude product, or the organic acids and water may be added separately.

As a device that can be used, a normal container equipped with a stirring device can be used.

Further, when reacting the phenols and olefins described above, the reactor used may be used as is.

After performing such a contact operation, oil and water are separated and the water layer is removed.

The standing time for oil/water separation is o. i to 5 hours, preferably 0.5 to 3 hours.

The process is carried out at room temperature to 100° C. and under normal pressure or increased pressure.

An ordinary oil-water separator can be used for this operation, and the container used in the operation of bringing the crude product into contact with the aqueous solution described above may be used as is.

In this manner, orthoalkylated phenols are quantitatively recovered in the oil phase after oil and water separation, and substantially no aluminum component is present.

The aluminum component quantitatively transfers to the aqueous phase.

The intended orthoalkylated phenols are then recovered by further distillation of the oil phase.

Since the boiling point differs depending on the type of orne-alkylated phenol, various conditions such as the degree of vacuum and temperature are appropriately selected as necessary. Since the aluminum component and the organic acids used are substantially absent, there is no change in the structure of the ortho-alkylated phenols in the crude product during the distillation operation, and therefore the ortho-alkylated phenols of the intended structure are not present. can be obtained in good yield, and the heating equipment used during distillation, such as a reboiler, will not be contaminated.

Each of the above steps can be carried out either batchwise or continuously.

This will be explained in detail below using examples.

Example 1 In the presence of aluminum phenoxide, inbutylene was used in a ratio of 2 moles to 1 mole of phenol, and a reaction was carried out at 110°C for 3 hours with stirring in an autoclave, resulting in a crude product having the following composition. I got something.

2゜6-di-t-butylphenol 68.2% by weight 2-t-butylwaenol 13.8 〃2.
4,6-tri-t-butyl 11.5 //Phenol aluminum phenoxide 0.25 /, (as aluminum) Unreacted phenol 1,2 "Unidentified compound 5.0 This crude product 1
00g was placed in a 300ml glass flask equipped with a stirrer, a sample inlet, and a liquid outlet, and 30g of an aqueous solution containing 17g of oxalic acid (corresponding to twice the mole of AI) was added at room temperature and pressure. The stirring operation was continued for 5 minutes.

When stirring was stopped and the mixture was allowed to stand for 1.0 hour, the oil phase and water phase were completely separated.

Almost no migration of phenols into the aqueous phase was observed.

When the aluminum content of the oil phase was analyzed by spectrophotometry, it was found to be below the detection limit (5 ppm).

In addition, the oil phase was analyzed by gas chromatography.
- The contents of 6-di-t-butylphenol, 2-t-butylphenol, and 2,4,6-tri-t-butylphenol were measured.

Furthermore, after heating the oil phase at 250° C. for 5 hours under a nitrogen atmosphere, the content of each of the above components was measured.

The above results are shown in Table 1.

Example 2 The same operation as in Example 1 was performed except that the contact temperature and standing temperature between the crude product and the aqueous solution in Example 1 were changed to 60°C.

The results are shown in Table 1. Example 3 In Example 1, 4.2 g of tartaric acid (corresponding to 3 times the mole of aluminum) was used instead of oxalic acid.

) The same operation as in Example 1 was carried out except that 30 g of an aqueous solution containing .

The results are shown in Table 1. Example 4 In Example 1, 3.9 g of citric acid (
It corresponds to twice the molar amount of aluminum.

) The same operation as in Example 1 was performed except for using the aqueous solution 302 containing .

The results are shown in Table 1.

Comparative Example 1 When the same operation as in Example 1 was carried out except that oxalic acid was not used and only 20 g of water was added in the contact treatment of the crude product and the aqueous solution, the whole product became gel-like and was left standing for 100 hours. However, the oil phase and water phase did not separate at all.

Next, this gel was coated with paper (40 m
mφ, No. When filtering was performed more vigorously using 7), 80 minutes of filtration time was required.

An oil phase corresponding to 20% by weight of the crude product remained on the surface of the aluminum hydroxide on the opening paper.

Comparative Example 2 In Comparative Example 1, the amount of water was 3.3 g, and the gel produced by contact treatment was transferred to a 300 ml autoclave.
Heat treatment was performed at 185°C for 30 minutes.

After cooling to room temperature, the treated liquid was subjected to the same filtration operation as in Comparative Example 1.

Filtration time required 25 minutes. An oil phase corresponding to about 10% by weight of the crude product remained on the aluminum hydroxide surface.

The results of Comparative Examples 1 and 2 show that it is extremely difficult to industrially implement the method of solid-liquid separation of gel once generated by filtration.

Comparative Examples 3, 4, 5, 6 Succinic acid (Comparative Example 3) was used instead of oxalic acid in Example 1.
), acetylacetone (Comparative Example 4), 8-oxyquinoline (Comparative Example 5), EDTA-2Na salt (Comparative Example 6), etc. were used in amounts equivalent to twice the mole of aluminum, and all has a gel-like appearance, and 100
Oil and water did not separate even after standing for hours.

Claims (1)

[Claims] 1. A method for removing an aluminum component from a crude product consisting of an orthoalkylated phenol and an aluminum component obtained by reacting a phenol with an olefin in the presence of an aluminum phenoxide compound. A process for producing an aluminum component, which comprises contacting the crude product with oxalic acid, citric acid, tartaric acid, or a mixture thereof and water to transfer the aluminum component to an aqueous phase, and then separating the aqueous layer. Removal method. 2 Oxalic acid, citric acid, tartaric acid, or a mixture thereof at 0.00% per mole of aluminum contained in the crude product.
2. The method according to claim 1, characterized in that 1 to 10 mol is used. 3. The method according to item 1 or 2, characterized in that 0.05 to 5 parts by weight of water is used per 1 part by weight of the crude product.