JPS63243046A - Production of tert-butylphenols - Google Patents

Abstract

PURPOSE:To obtain mono-tert butylphenols selectivity and in high yield, by reacting a phenol with isobutene or isobutene-containing gas in the presence of a heteropoly acid at a specific temperature and subjecting the reaction product to rearrangement reaction at a specific temperature. CONSTITUTION:A phenol, especially m- or p-cresol, is reacted with isobutene or isobutene-containing gas in the presence of a heteropoly acid, especially tungstosilicic acid at 30-130 deg.C, preferably 40-80 deg.C to a give mono- and di-tert butylphenols. Then the butylphenols are successively subjected to rearrangement reaction at 100-180 deg.C, preferably 105-140 deg.C to give mono-tert butyl phenols such as 4-methyl-6-tert butyl phenol useful as an antioxidant from inexpensive raw materials in high purity, in high yield, industrially and readily while suppressing formation of secondary alkylphenols as by-products.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel method for selectively producing mono-tert and butylphenols in good yield from phenols and isobutene or isobutene-containing gas. .

Mono-tert, butylphenols, especially 4-medyru [3-tert] obtained by the process of the invention.

Butylphenol, 3-methyl-6-tert, butylphenol or 2-methyl-4-tert, butylphenol, etc. are used as antioxidants, stabilizers, ultraviolet absorbers, intermediates for pesticides or dyes, raw materials for phenolic resins, etc. It is useful.

[Conventional technology]

Processes for producing alkylphenols, particularly mono-tert, butylphenols, by alkylation of phenols with branched olefins are well known and are generally used to suppress the formation of by-products such as secondary alkylphenols. , it is recommended to use high-purity hydrocarbon feedstocks.

However, this method requires the separation and purification of isobutene from a mixture containing isobutene, such as light components produced by cracking petroleum products, and is therefore industrially disadvantageous.

As an industrially and economically advantageous method for producing mono-tert and butylphenols, a method of reacting a mixture containing isobutene with phenols has been considered.
Various studies have been made. However, it is very difficult to selectively react isobutene in a mixture, ie, a mixed gas containing isobutene, and many searches for highly selective catalysts have been conducted and various catalysts have been proposed.

All of these conventionally known methods have the disadvantage that increasing the selectivity lowers the reaction rate and also lowers the absorption rate of isobutene. Moreover, increasing the reaction rate increases the utilization rate of isobutene, but increases the production of secondary alkylphenols and polymers of isobutene and other olefin gases, making cleaning and purification operations of the target product extremely complicated. Moreover, the resulting waste liquid requires special treatment.

Further, since the exhaust gas contains a large amount of the above-mentioned polymer, it cannot be used as a fuel as it is, and purification and separation operations are required, which is also not industrially practical.

When using conventionally known catalysts such as sulfuric acid and toluenesulfonic acid, sulfonated products and neutral esters (
Butyl sulfate, etc.) are generated, and even after neutralization and washing, these esters remain in the reaction product, and when heated at high temperatures during distillation, they act as a dealkylation catalyst, resulting in high quality and high yield. It is known that the mono-alkylphenols of

For this reason, conventionally, the reaction product is neutralized with an alkaline aqueous solution under high temperature and pressure to decompose esters and the like [Industrial and Engineering Chemistry Vol. 35, pp. 265-272 (1943)].

Furthermore, these catalysts have various problems, such as severe equipment corrosion and the need for equipment made of high-grade materials for industrial implementation.

[Problem that the invention seeks to solve]

In view of the above circumstances, the present inventors have made effective use of raw material gas,
As a result of intensive research into suppressing side reactions caused by butene-1, butene-2, etc. and preventing polymerization of isobutene, etc., we found that the above objectives can be achieved by using a heteropolyacid as a catalyst and treating at a specific temperature. The present inventors have discovered that the following can be achieved, and have completed the present invention.

Therefore, the object of the present invention is to suppress the by-product of secondary alkylphenols while using inexpensive mixed butene gas as a raw material, and to industrially easily produce high-purity mono-tert and butylphenols in high yields. The goal is to give you a way to do it.

The main object of the present invention is to produce phenols such as 4-methyl-6-tert, butylphenol, 3-methyl-6-tert, butylphenol, 2-methyl-4-tert, butylphenol, etc. with high purity and high yield in a short time. and isobutene or a gas containing isobutene.

[Means for solving problems]

In the present invention, in the presence of a heteropolyacid, phenols and isobutene or a gas containing isobutene are reacted at a temperature of 3.
Mono- and di-t
ert, butylphenols are produced, and the obtained butylphenols are subsequently heated at a reaction temperature of 100°C to 18°C.
Mono-tert characterized by a rearrangement reaction at 0°C
, a method for producing butylphenols.

That is, in the presence of a heteropolyacid, phenols and isobutene or a gas containing isobutene are mixed at 30 to 1
When the reaction is carried out at a temperature below 00°C, butylphenols consisting of mono-tert and butylphenols to which only isobutene is selectively added and di-tert and butylphenols can be obtained in good yield. Subsequently, this butylphenol is subjected to a rearrangement reaction at a temperature of 100°C to 180°C to form di-tert, 1 of butylphenol.
butyl groups are rearranged to the raw material phenols to produce 4-methyl-6-tert, butylphenol, 3-methyl-
6-tert, butylphenol, 2-methyl-4-t
ert.

It was discovered that the above object could be achieved by changing it to butylphenol, etc., and the present invention was completed.

The present invention will be explained in more detail below.

<Raw materials> Phenols include phenol, O-cresol,
Examples include m-cresol and p-cresol.

The gas containing isobutene is a C4 hydrocarbon mixture obtained by removing butadiene from the C4 fraction obtained from the steam cracking process of naphtha, etc.
Contains about 0 to 60%, with butene-1 as other components
, butene-2, n-butane, etc., hereinafter referred to as L
It is abbreviated as BB.

In carrying out the present invention, the molar ratio of isobutene to phenols is usually 0.5 to 3.
, preferably 0.6 to 1.5.

In the rearrangement reaction that follows the reaction between phenols and isobutene or isobutene-containing gas, te
rt, butyl groups can be effectively rearranged with unreacted raw material phenols by changing the charging molar ratio, the order of addition of raw materials and reaction products, etc. For example, in the rearrangement reaction, g-tert, butylphenols, etc. may be added before the temperature is raised, or raw material phenols may be added before the temperature is raised.

<Catalyst> The method of the present invention requires the use of a heteropolyacid as a catalyst. The term "heteropolyacid" as used in the present invention refers to an acid produced by two or more metals among polyacids formed by combining with an inorganic acid, and generally one
It is a general term for things formed by centering on a seed metal (or heteroatom) and coordinating it with other metals (polyatoms) via oxygen, etc. Here, examples of the heteroatom include boron, aluminum, silicon, phosphorus, titanium, germanium, arsenic, zirconium, tin, tellurium, and the like. In addition, as poly atoms, molybdenum,
Examples include tungsten, vanadium, and niobium.

Specifically, molybdophosphoric acid, molybdosilicic acid, molybdoarsenic acid, molybdotelluric acid, molybdoaluminate, tungstosilicic acid, tungstophosphoric acid, tungstoboric acid,
Tungstotitanic acid, tungstostannic acid, etc., and among these, molybdophosphoric acid, molybdosilicic acid, tungstophosphoric acid, tungstosilicate, etc. are preferably used. Note that these heteropolyacids are usually used in the form of hydrates.

The amount of catalyst used varies depending on the reaction type and other conditions, but is usually 0.00001 to 0.3 times the weight of the phenol, preferably 0.0001 to 0.1 times the weight of the phenol.
More preferably, it is 0.0002 to 0.03 times by weight.

<Reaction conditions> In order to react isobutene or LBB with phenols in the present invention, it is possible to charge isobutene or LBB continuously or all at once into a reaction tank containing heteropolyacid and phenols, but it is possible to charge isobutene or LBB continuously or all at once. Alternatively, it is desirable to release unreacted components to the outside of the reaction system by intermittently combining introduction and exhaust.

It goes without saying that the reaction can also be carried out by continuously introducing phenols, heteropolyacids, and isobutene.

The butylation reaction temperature in the first stage of the present invention is usually 30 to
The temperature is 100°C, preferably 40 to 80°C; if this temperature is too low, the reaction rate will be slow, and if it is too high, by-products will be produced in large quantities, which is not preferred.

The reaction pressure is normal pressure to 20 kg/cnt, preferably normal pressure to 10 kg/cd. When the reaction is carried out under such reaction conditions, the reaction is generally completed in 0.5 to 10 hours.

The heteropolyacid of the catalyst varies depending on the reaction conditions, but
It can be used undissolved, that is, in a heterogeneous state. In this case, water, acetone, or a lower aliphatic alcohol such as methanol may be present as a diluent or solubilizer.

In particular, the coexistence of water gives good results. The amount of water to be used is 01 to 20 times, preferably 0.5 to 5 times the weight of the heteropolyacid.

The subsequent rearrangement reaction may be carried out in the same vessel as the reaction or in a separate vessel. Alternatively, it may be continuously supplied to a reaction zone maintained at a predetermined temperature.

Although conventionally known catalysts can be used in this rearrangement reaction, it is preferable to use the catalyst used in the butylation reaction in the previous stage.

It is efficient to heat the mass after the reaction as it is without separating the heteropolyacid catalyst used in the butylation reaction.

The heating temperature in the rearrangement reaction is 1.00 to 18 [t, preferably 105 to 140°C, and the holding time after reaching the predetermined temperature is usually 0 to 5 hours, which is sufficient.

The amount of heteropolyacid to be used depends on the reaction temperature, but is 0.00001 to 0.3 times the weight of the product, preferably 0.
．． 0001 to 0.1 times the weight. Therefore, although the heteropolyacid used during the reaction with isobutene is sufficient, a desired amount of heteropolyacid may be added before the dealkylation reaction. At this time, it is not necessary to limit to the same type of heteropolyacid.

<Treatment after reaction> The mixture after the reaction is usually neutralized or washed with alkaline water or water, and then the mixture is distilled by a conventional method to obtain the desired tert.

Butylphenols can be recovered.

[Results of the invention]

The heteropolyacid used in the method of the present invention is highly active and has a high selectivity for alkylphenols, especially tertiary alkylphenols, and can obtain the desired mono-tert and butylphenols in high yield and purity. Additionally, the fact that equipment is less corrosive and is made of inexpensive materials is sufficient.
It is extremely useful for industrial implementation.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the examples, parts and % mean times by weight or % by weight, respectively.

Example 1 115 parts of m-cresol and 0.086 parts of tungstosilicic acid
130 parts of LBB gas (isobutene content: 45%) was blown into the flask over 4 hours while stirring and maintaining the temperature at 65 to 72°C.

The composition of the reaction mixture after completion of blowing was as follows.

m-cresol 20.0
%3-methyl-6-tert, butylphenol 60
．． 5% 3-methyl-4,6-tert, butylphenol 14.3%
3-methyl-4-tert, butylphenol 2.8
%Other 2.4%
Subsequently, the temperature was raised to 115°C and kept for 2 hours, then cooled and the reaction product was washed with water and alkali.
5 parts of oil were obtained. The composition of this oil was analyzed by gas chromatography and found to be as follows.

m-cresol 15.0
%3-Methyl-(3-tert, butylphenol 7
8.0% 3-methyl-4,6-tert, butylphenol 3.0% 3-methyl-4-tart, butylphenol 0.5% Others 3.5% m-cresol, 3-methyl-6-tert, Butylphenol, 3-methyl-4,6-ditert.

The total balance of butylphenol, 3-methyl-4-tert, and butylphenol (versus m-talesol charged) is 9
It was a good 7%.

The desired products, 3-methyl-5-tert and butylphenol, are extracted from the reaction mixture by vacuum rectification with a boiling point of 128-13
127 parts were obtained as a 11 g fraction at 1° C./20 mm.

Example 2 108 parts of p-cresol, 0.2 parts of tungstosilicic acid, and 0.2 parts of water were charged into a flask and heated to 50 to 55°C while stirring.
LBB gas (isobutene content 45%)27
I blew 5 parts in 7 hours.

The composition of the reaction mixture after completion of blowing was as follows.

p-cresol 1.5%4
-methyl-6-tert, butylphenol
8.7% 4-methyl-2,6
-Stert, butylphenol
87.5% Others
54 parts of 2.3% p-cresol was added, and the temperature was subsequently raised to 120°C. After being kept at the same temperature for 2 hours, it was cooled and the reaction product was washed with water and alkali to obtain 240 parts of an oily substance.

The composition of this oil was analyzed by gas chromatography and found to be as follows.

p-cresol 3.0
%4-methy)'-6-tert, butylphenol
90.5% 4-Methyl-2,6-tert, butylphenol 2.5% Others 4.0% The target product, 4-methyl-6-tert, butylphenol, is extracted from the reaction mixture with a boiling point of 125 to 125% by vacuum rectification. 12
Obtained as a fraction of 11 g at 8° C./20 mm.

Example 3 50 parts of 0-cresol and 0.05 part of tungstophosphoric acid were charged into a flask, and while stirring and maintaining the temperature at 70 to 75°C, L
58 parts of B B gas (isobutene content 45%) was blown in over 2 hours.

Subsequently, the temperature was raised to 125° C. and maintained for 2 hours, then cooled and the reaction product was washed with water and alkali to obtain 73 parts of an oily substance. The composition of this oil was analyzed by gas chromatography and found to be as follows.

0-Cresol 16.0
%2-Methyl-(3-tert, butylphenol 3
．． 0% 2-methyl-4-tert, butylphenol
72.5% 2-methyl-4,6-tert, butylphenol 4.0% Others 4.5% The desired products, 2-methyl-4-tert, butylphenol, can be easily obtained from the reaction mixture by vacuum rectification. Ta.

Comparative Example 115 parts of m-cresol and 2.1 parts of 98% sulfuric acid were charged into a flask, and 130 parts of LBB gas (isobutene content: 45%) was blown into the flask over 4 hours while stirring and maintaining the temperature at 68 to 72°C.

゛ The composition of the reaction mixture after completion of blowing was as follows.

m-cresol 15%
3-methyl-6-tert, butylphenol 64
%3-Methyl-4,6-tert, butylphenol 10%3-methyl-4-tert, butylphenol 2%Others
9% continues to be 115
After raising the temperature to .degree. C. and keeping the temperature for 2 hours, it was cooled, and the reaction product was washed with alkaline water and water at 100.degree. C. for 1 hour, yielding 160 parts of an oily substance. The composition of this oil was analyzed by gas chromatography and found to be as follows.

m-cresol 12%
3-methyl-6-tert, butylphenol 59
%3-methyl-4,6-tert,butylphenol 2%3-methyl-
4-tert, butylphenol 1% others
26% m-cresol,
3-methyl-[3-tert, butylphenol, 3-
Methyl-4,6-tert.

The total balance of butylphenol, 3-methyl-4-tert, and butylphenol (versus m-cresol charged) is 7
The amount was as low as 3%, and a large amount of other components were produced as by-products.

The desired products, 3-methyl-6-tert and butylphenol, are extracted from the reaction mixture with a boiling point of 128 to 1 by distillation under reduced pressure.
Only 82 parts were obtained as a fraction of 11 g at 31° C./20 mm. This is because debutylation occurs during vacuum rectification, resulting in a low yield of 86% for extraction of 3-methyl-6-tert and butylphenol in the rectification process alone.

19 (event)

Claims (5)

[Claims] (1) In the presence of a heteropolyacid, phenols and isobutene or a gas containing isobutene are reacted at a temperature of 30°C.
Mono- and di-ter
t. Butylphenols are produced, and the obtained butylphenols are subsequently treated at a reaction temperature of 100°C to 180°C.
A mono-tert. A method for producing butylphenols. (2) The method according to claim 1, wherein the alkylation reaction temperature in the first stage is 40 to 80°C, and the rearrangement reaction temperature in the second stage is 105 to 140°C. (3) The method according to claim 1 or 2, wherein the phenol is m-cresol. (4) The method according to claim 1 or 2, wherein the phenol is p-cresol. (5) The method according to claims 1 to 4, wherein the heteropolyacid is tungstosilicic acid.