JPH10273460A - Production of 3,3',5,5'-tetra-t-butylbiphenol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for production by which 3,3',5,5'-tetra- t-butylbiphenol can be obtained in high yield and can further be produced by a batch method and continuously be produced by uniformly dispersing an alkali metallic catalyst in raw materials. SOLUTION: This method for producing 3,3',5,5'-tetra-t-butylbiphenol comprises using a catalyst composition composed of an alkali metallic catalyst and alkylphenols or the one composed of the alkylphenols and phenol as an alkali metallic catalyst when reacting (i) the purified 2,6-di-t-butylphenol or (ii) phenol with isobutylene, then removing an aluminum catalyst, carrying out the oxidative dimerizing reaction of the resultant crude 2,6-di-t-butylphenol in the presence of the alkali metallic catalyst and producing the 3,3',5,5'-tetra- t-butylbiphenol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol, and more particularly, to a method for producing 3,3', 5,5'-tetra-t-butylbiphenol.
3,3 ', 5,5'-Tetra-t-butylbiphenol useful as a raw material such as 4,4'-biphenol is purified 2,6-di-t-butylphenol or crude 2,6-di-t-butylphenol. The present invention relates to a method for producing butylphenol by an oxidative coupling reaction.

[0002]

BACKGROUND OF THE INVENTION Hitherto, it has been known to use an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide as a catalyst in the oxidative coupling reaction of 2,6-di-t-butylphenol. I have.

JP-A-5-97740 discloses that the above-mentioned alkali metal hydroxide can be used as an aqueous solution or can be used in an anhydrous or solvent-free state.

However, as described above, an alkali metal catalyst such as an alkali metal hydroxide is dissolved in an aqueous solution (for example,
(8% KOH aqueous solution) and used as a catalyst, the solubility of the alkali metal catalyst in 2,6-di-t-butylphenol is low. Due to the evaporation of water, the alkali metal catalyst cannot be uniformly dispersed in the 2,6-t-butylphenol in the reactor.

[0005] Therefore, the reaction rate of the oxidative coupling becomes slow and impurities increase, so that 3,3 ', 5,5'-tetra
There were problems that the yield of -t-butyl biphenol was reduced and that the air blowing port of the reaction tank was easily clogged.

[0006] When a situation of heterogeneous dispersion of the alkali metal catalyst occurs in the reaction system, the oxidation reaction cannot be continuously performed. In order to prevent the reaction rate of the oxidative coupling from decreasing, a large amount of an alkali metal catalyst is used. In this case, a large amount of an acid catalyst for neutralization is used.

The inventors of the present invention have made intensive studies to solve the above-mentioned problems. In the catalytic oxidation coupling reaction of 2,6-di-t-butylphenol, t-butylphenols and the like are used as alkali metal catalysts. Alkylphenols, or
When a mixed solution of alkylphenols such as t-butylphenols and phenol coexist, the solubility of the alkali metal catalyst in 2,6-di-t-butylphenol increases significantly, so that the oxidation reaction proceeds uniformly, There are few by-products such as carbon dioxide or 2,6-di-t-butylbenzoquinone,
The inventors have found that 3,3 ′, 5,5′-tetra-t-butylbiphenol can be produced with high oxidation efficiency, and have completed the present invention.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, and to disperse the alkali metal catalyst evenly so that 3,3 ', 5,5'-tetra -t
-It is an object of the present invention to provide a method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol capable of continuously producing butylbiphenol in a high yield.

[0009]

SUMMARY OF THE INVENTION The process for producing 3,3 ', 5,5'-tetra-t-butylbiphenol according to the present invention comprises the steps of (i) purifying 2,6-di-t-butylphenol or (ii) phenol. After reacting isobutylene and removing the aluminum catalyst, the crude 2,2
In producing 3,3 ', 5,5'-tetra-t-butylbiphenol by oxidizing and dimerizing 6-di-t-butylphenol in the presence of an alkali metal catalyst, an alkali metal catalyst is used as an alkali metal catalyst. It is characterized by using a catalyst preparation (1) comprising a catalyst and an alkylphenol or a catalyst preparation (2) comprising an alkali metal catalyst, an alkylphenol and a phenol.

The content of the alkylphenols in the catalyst formulations (1) and (2) is determined by the alkali metal catalyst 1
It is preferable that the amount is in the range of 1 to 5 mole times with respect to the mole, and the amount of water in the catalyst preparation is in the range of 2 to 20% by weight. The weight ratio of alkylphenols to phenol [alkylphenols / phenol] in the catalyst preparation (2) is preferably 70/30 or more.

The above catalyst preparation (1) and catalyst preparation (2) dissolve instantaneously in the 2,6-di-t-butylphenol reaction solution. Therefore, according to the present invention, 3,3 ', 5,5'-tetra
The method for producing -t-butyl biphenol allows continuous feed of raw materials and catalyst, and is optimal for continuous production of 3,3 ', 5,5'-tetra-t-butyl biphenol.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol according to the present invention will be specifically described.

In the method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol according to the present invention, (i) purified 2,6-di-t-butylphenol or (ii) phenol is added with isobutylene. After the reaction, the crude catalyst obtained by removing the aluminum catalyst 2,
In producing 3,3 ', 5,5'-tetra-t-butylbiphenol by oxidizing and dimerizing 6-di-t-butylphenol in the presence of an alkali metal catalyst, an alkali metal catalyst is used as an alkali metal catalyst. A catalyst preparation (1) comprising a catalyst and an alkylphenol or a catalyst preparation (2) comprising an alkali metal catalyst, an alkylphenol and a phenol is used.

[0014] raw material used in the present invention 3,3 ', raw material 5,5' -t- butyl biphenol, purified 2,6-di -t- butylphenol or crude 2,6-di -t- Butylphenol.

As the crude 2,6-di-t-butylphenol,
For example, 2,6-produced from phenol and isobutylene as described in JP-B-6-74227.
Examples include a 2,6-di-t-butylphenol composition containing di-t-butylphenol and by-products.

In the process for producing p, p'-biphenol described in Japanese Patent Publication No. 6-74227, crude 2,6-
Di-t-butylphenol (including 2,6-di-t
2,6-di-t-butylphenol content in the butylphenol composition is 73 to 82% by weight, and phenol and pt-butylphenol (PTB
The content of P) is 0.5% by weight or less.

Alkali metal catalyst Examples of the alkali metal catalyst used in the present invention include alkali metal hydroxides, carbonates and bicarbonates. Among them, an alkali metal hydroxide is preferably used. A preferred form is an aqueous solution of an alkali metal hydroxide. The alkali metal is preferably sodium and potassium, and more preferably potassium.

The amount of the alkali metal catalyst to be used is not particularly limited. However, when the amount is too small, the reaction becomes slow, and when the amount is too large, a large amount of neutralizing acid is required, so that usually 2,6-di-t-butylphenol 100 is charged. It is preferably from 0.3 to 1.5 mol% with respect to mol%.

In the present invention, the alkali metal catalyst comprises:
It is used as a catalyst preparation (1) mixed with an alkylphenol or a catalyst preparation (2) mixed with a mixture of an alkylphenol and phenol.

Examples of the alkylphenols used in the above catalyst preparations (1) and (2) include t-butylphenols, cresols, xylenols, propylphenols, sec-butylphenols, and mixtures thereof. Can be Among them, t-butylphenols are preferred.

As the t-butylphenols, specifically, ot-butylphenol (OTBP), pt-butylphenol (PTBP), mt-butylphenol (MTB)
P), 2,4-di-t-butylphenol (2,4 TBP) or a mixture thereof. In particular, pt-butylphenol is preferably used.

The amount of the alkylphenol (solvent) such as t-butylphenol used is not particularly limited, but is preferably such that the concentration of the alkali metal catalyst is 5 to 15%.
If the alkali concentration is too high, the mixture of the alkali metal catalyst and the alkylphenol is unlikely to become liquid at low temperatures. On the other hand, if the alkali concentration is too low, a large amount of alkylphenols for preparing the catalyst is required, and the oxidative coupling by-product of the alkylphenols and 2,6-di-t-butylphenol increases. Further, it is preferable to adjust the amount of water in the catalyst preparation within the range of 2 to 20% by weight. If the water content is too low, the freezing point of the catalyst formulation will be high, making it difficult for it to become liquid at low temperatures. On the other hand, if the water content is too high, the solubility of the catalyst preparation in 2,6-di-t-butylphenol decreases, and the catalyst preparation tends to settle at the bottom of the reaction tank as a droplet.

The content of the alkylphenols in the above catalyst preparations (1) and (2) is usually in the range of 1 to 5 moles, preferably 2 to 4 moles per mole of the alkali metal catalyst. The amount of water in the catalyst formulation was 2
-20% by weight, preferably 5-15% by weight.

When the above crude 2,6-di-t-butylphenol composition is used as a raw material of 3,3 ′, 5,5′-tetra-t-butylbiphenol, it is mixed with an alkyl metal catalyst. When determining the amount of alkylphenols to be blended,
By-product ot-butylphenol (OTBP), pt-
Butylphenol (PTBP), 2,4-di-t-butylphenol (2,4TBP), 2,4,6-tri-t-butylphenol
The amount of alkylphenols such as (2,4,6 TBP) is also considered.

In the present invention, in order to lower the freezing point of the catalyst preparation (1) comprising an alkali metal catalyst and an alkylphenol, a mixture of the above alkylphenol and phenol is used instead of the alkylphenol. Can be. That is, the catalyst preparation (2) is used instead of the catalyst preparation (1).

As the above mixture, a mixture of p-alkylphenols and phenol is preferable, and a mixture of pt-butylphenol and phenol is particularly preferable. The weight ratio of alkylphenols to phenol [alkylphenols / phenol] in such a catalyst preparation (2) is preferably 70/30 or more. In this case, if the proportion of phenol is too high, the situation is the same as that of the case of using the aqueous alkali metal hydroxide solution alone, and this mixture will settle at the bottom of the reaction tank as a droplet.

When a crude 2,6-dialkylphenol composition as described above is used as a raw material for 3,3 ', 5,5'-tetra-t-butylbiphenol, alkylphenols prepared with an alkyl metal catalyst may be used. In determining the amount of phenol and phenol, the amounts of alkylphenols and phenol, which are by-products, are also taken into consideration.

The method of mixing the alkali metal catalyst with the alkylphenols and phenol is not particularly limited, but usually, the alkali metal catalyst is added to a mixture obtained by mixing the alkylphenols and phenol at a predetermined ratio. Mix.

If the alkali metal catalyst is a solid, it is necessary to heat and dissolve the catalyst. Further, when the alkali metal catalyst is an aqueous solution of a hydroxide, the aqueous solution of the alkali metal hydroxide is mixed with a mixed solution of an alkylphenol and a phenol and then heated and dehydrated. It is preferable to use it in a mixed state.

Alkali metals, alkylphenols, and a mixture of alkylphenols and phenol used as a catalyst may be a purified 2,6-di-t-butylphenol, a 2,6-di-t-butylphenol composition, or a mixture thereof. It can be used in a batch reaction or a continuous reaction because it is arbitrarily dissolved in the oxidation reaction solution of the above.

That is, purified 2,6-di-t-butylphenol or crude 2,6-di-t-butylphenol and the above-mentioned catalyst preparation (1) or (2) are added, and the mixture is heated to a predetermined temperature. The oxidation reaction can be carried out by blowing an oxygen-containing gas such as air after that, and furthermore, while performing the oxidation reaction, purified 2,6-di-t-butylphenol or crude 2,6-
It is also possible to continuously charge 6-di-t-butylphenol and the catalyst preparation (1) or (2).

The above-mentioned catalyst preparation (1) or (2),
Purified 2,6-di-t-butylphenol or crude 2,6-di-t-butylphenol can be introduced separately into the reactor or the catalyst preparation can be added immediately before introducing them into the reactor. (1) or (2) and purified 2,6-di-t-butylphenol or crude 2,6-di-t-butylphenol may be mixed and introduced into the reaction vessel.

The oxidation reaction temperature is 150 to 250 ° C., preferably 180 to 200 ° C., and the reaction pressure may be normal pressure or pressurization, but preferably 1 to 5 kg / cm ² . As the oxygen source used for the oxidation reaction, pure oxygen, air, or an inert gas-diluted oxygen-containing gas can be used, but usually air or nitrogen gas-diluted air is preferred.

The oxygen absorption amount of 2,6-di-t-butylphenol, which is a raw material of 3,3 ′, 5,5′-tetra-t-butylbiphenol, is 100 mol of 2,6-di-t-butylphenol charged. %, And preferably 15 to 25 mol% with respect to the total%.

When the oxygen absorption is small, a large amount of 2,6-di-t-butylphenol remains, and as a result, 3,3 ′, 5,5′-tetra
The yield of -t-butyl biphenol is low. On the other hand, if the amount of absorbed oxygen is too large, a large amount of by-products such as diphenoquinone (DPQ) is generated.

[0036]

According to the method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol according to the present invention, the oxidative coupling reaction is uniformly performed by uniformly dispersing the alkali metal catalyst in the raw material. Therefore, 3,3 ′, 5,5′-tetra-t-butylbiphenol can be obtained in high yield.

Further, according to the present invention, 3,3 ′, 5,5′-tetra-t-
According to the method for producing butyl biphenol, 3,3 ′, 5,5′-tetra-t-butyl biphenol can be produced in a batch system or can be produced continuously.

[0038]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

[0039]

Example 1 First, phenol was reacted with isobutylene in the presence of an aluminum phenoxide catalyst by a conventionally known method, and then the aluminum phenoxide catalyst was removed to obtain crude 2,6-di-t-butylphenol. .

This crude 2,6-di-t-butylphenol is composed of 0.5% by weight of phenol, 4.8% by weight of ot-butylphenol, 0.6% by weight of pt-butylphenol, and 2,4-di-t-phenol as impurities. -1.3% by weight of butylphenol and 2,
It contains 15% by weight of 4,6-tri-t-butylphenol and the main product, 2,6-di-t-butylphenol, is 7%.
It was 7.3% by weight.

The above crude 2,6-di-t-butylphenol 600
g was charged into a 1 liter cylindrical glass flask having an inner diameter of 80 mm and a height of 180 mm, and after purging with nitrogen gas,
The temperature was raised to 195 ° C.

In this solution, pt-butylphenol (PTB)
P) A mixture of 80 g of phenol (PhOH) and 10 g of phenol (PhOH) was added with 25 g of a 48% aqueous potassium hydroxide solution, and 10 g of the alkali metal catalyst mixture was dropped from the top of the cylindrical glass flask. Instantaneously dissolved to form a homogeneous solution.

The crude 2,6-di-t-containing alkali metal catalyst
500 g of butylphenol was transferred to a 1-liter autoclave, and without stirring, the reaction temperature was 195 ° C.
At a reaction pressure of 3 kg / cm ² -G, 150 ml /
Oxidation coupling reaction was performed by blowing at a rate of minutes for 6 hours.

The gas chromatographic analysis composition of this oxidation reaction solution was such that unreacted 2,6-di-t-butylphenol was 1
4.3% by weight, 61.5% by weight of 3,3 ', 5,5'-tetra-t-butylbiphenol, and the oxidation rate of 2,6-di-t-butylphenol was 81.8% by mole. Yes, it is the object 3,
The yield of 3 ', 5,5'-tetra-t-butylbiphenol is 7
9.4 mol% (based on 2,6-di-t-butylphenol charged)
Met.

[0045]

Example 2 In place of crude 2,6-di-t-butylphenol in Example 1, 600 g of purified 2,6-di-t-butylphenol having a purity of 99.9% was used, having an inner diameter of 80 mm and a height of 180 m.
m in a 1 liter cylindrical glass flask,
After purging with nitrogen gas, the temperature was raised to 195 ° C.

In this solution, pt-butylphenol (PTB)
P) A mixture of 80 g of phenol (PhOH) and 10 g of phenol (PhOH) was added with 25 g of a 48% aqueous solution of potassium hydroxide, and 10 g of an alkali metal catalyst formulation was dropped from the top of the cylindrical glass flask. Similarly, the alkali metal catalyst formulation dissolved instantaneously, resulting in a homogeneous solution.

The purified 2,6-di-t containing the alkali metal catalyst
-Transfer 500 g of butylphenol to a 1 liter autoclave and stir without stirring at a reaction temperature of 195;
150 m of air under the conditions of ° C and a reaction pressure of 3 kg / cm ² -G
The oxidative coupling reaction was performed by blowing at a rate of 1 / min for 8 hours.

The gas chromatographic analysis composition of this oxidation reaction mixture was such that unreacted 2,6-di-t-butylphenol was 1
5.4% by weight, 3,3 ', 5,5'-tetra-t-butylbiphenol was 83.1% by weight, and the oxidation rate of 2,6-di-t-butylphenol was 84.6% by mole. Yes, it is the object 3,
The yield of 3 ', 5,5'-tetra-t-butylbiphenol was 8
3.6 mol% (based on 2,6-di-t-butylphenol charged)
Met.

[0049]

Embodiments 3 and 4 600 g of the crude 2,6-di-t-butylphenol obtained in the above-mentioned embodiment 1 was prepared by adding 1 g of an inner diameter of 80 mm and a height of 180 mm.
After charging into a liter-capacity cylindrical glass flask and purging with nitrogen gas, the temperature was raised to 195 ° C.

In this solution, a 48% aqueous solution of potassium hydroxide, pt-butylphenol (PTBP) and phenol (PhOH)
Various alkali metal catalyst preparations shown in Table 1 below were synthesized, and their liquids were separately dropped from the upper part of the cylindrical glass flask in an amount of about 10 g each. Was observed.

As a result, any of the alkali metal catalyst formulations shown in Table 1 was obtained in the same manner as in Example 1 except that the crude 2,6-di-t-
It dissolves almost instantly in butylphenol to form a homogeneous solution.

[0052]

[Table 1]

[0053]

Examples 5 to 7 In a 500 ml four-necked flask,
100 g of a mixture of t-butylphenols and phenol
And a predetermined amount of a 48% aqueous solution of potassium hydroxide was added thereto. The mixture was heated to 200 ° C. and dehydrated, and various alkali metal catalyst preparations shown in Table 2 below (all solid at room temperature)
Was synthesized.

These alkali metal catalyst preparations (solid)
Was charged into a cylindrical glass flask similar to that of Example 1, 600 g of crude 2,6-di-t-butylphenol having the same composition as that of Example 1, and after purging with nitrogen gas, the temperature was raised to 195 ° C. Each of the alkali metal catalyst preparations (cake) shown in Table 2 was separately added in an amount of 5 to 10 g from the upper portion of the flask, and the dissolution state of the alkali metal catalyst preparation cake was observed.

As a result, any of the alkali metal catalyst blended cakes shown in Table 2 was found to have a crude 2,6-
Dissolved instantaneously in di-t-butylphenol.

[0056]

[Table 2]

[0057]

Comparative Example 1 Crude 2,6-di-t-t having the same composition as in Example 1
Butylphenol 600g is 80mm inside diameter, 180
The mixture was charged into a cylindrical glass flask having a capacity of 1 liter of 1 mm and purged with nitrogen gas, and then heated to 195 ° C.

2.6 g of a 48% aqueous solution of potassium hydroxide was added to this solution.
Is dropped from the top of the cylindrical glass flask, the aqueous potassium hydroxide solution settles down to the bottom of the flask as droplets,
After boiling the water, the catalyst KOH aggregated at the bottom of the flask.

The crude 2,6-di-t-containing alkali metal catalyst
500 g of the supernatant of butylphenol was transferred to an autoclave having a capacity of 1 liter.
At 15 ° C. and 95 ° C., the reaction pressure is 3 kg / cm ² -G.
The oxidation coupling reaction was carried out by blowing at a rate of 0 ml / min for 6 hours, but the reaction was slow and stopped during the reaction.

The gas chromatographic analysis composition of this oxidation reaction solution was such that unreacted 2,6-di-t-butylphenol was 5
2.1% by weight, 2,3 ', 5,5'-tetra-t-butylbiphenol was 23.7% by weight, and the oxidation rate of 2,6-di-t-butylphenol was 33.0% by mole. Yes, it is the object 3,
The yield of 3 ', 5,5'-tetra-t-butylbiphenol was 3
0.5 mol% (based on charged 2,6-di-t-butylphenol)
And was very low.

[0061]

Comparative Examples 2 to 4 600 g of crude 2,6-di-t-butylphenol having the same composition as in Example 1 or purification having a purity of 99.9% was placed in a cylindrical glass flask similar to that of Example 1. After charging 600 g of 2,6-di-t-butylphenol and purging with nitrogen gas, the temperature was raised to 195 ° C.
%, 24%, and 6% aqueous solutions of potassium hydroxide were separately added from the top of the flask in an amount of 5 to 10 g, and the dissolution state of the droplets was observed.

As a result, in any of the cases shown in Table 3 below, similarly to Comparative Example 1, after the potassium hydroxide aqueous solution settled to the bottom of the flask as a droplet, water boiled and the catalyst KOH was removed from the flask. Agglomerated at the bottom.

[0063]

[Table 3]

[0064]

Comparative Examples 5 to 7 600 g of crude 2,6-di-t-butylphenol having the same composition as in Example 1 was charged into an apparatus similar to that of Examples 1 to 3, and the atmosphere was replaced with nitrogen gas.
Each of the alkali metal catalyst formulations shown in Table 4 below was separately added to the liquid heated to 5 to 10 g from the top of the flask, and the dissolution state of the droplets was observed.

As a result, in any of the cases shown in Table 4 below, as in Comparative Example 1, the aqueous potassium hydroxide solution settled down to the bottom of the flask as droplets, and the water boiled after coming into contact with the bottom of the flask. Then, the catalyst KOH aggregated at the bottom of the flask.

[0066]

[Table 4]

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoichiro Isoda 2-115, Kozaiga, Wakayama-shi, Wakayama Pref.

Claims (4)

[Claims] 1. A crude 2,6-di-t-butylphenol obtained by reacting (i) purified 2,6-di-t-butylphenol or (ii) phenol with isobutylene and then removing an aluminum catalyst. Oxidative dimerization reaction in the presence of an alkali metal catalyst,
In producing 3 ', 5,5'-tetra-t-butylbiphenol, a catalyst preparation (1) comprising an alkali metal catalyst and an alkylphenol, or an alkali metal catalyst, an alkylphenol and a phenol as an alkali metal catalyst. A process for producing 3,3 ', 5,5'-tetra-t-butylbiphenol, comprising using a catalyst preparation (2) comprising: 2. The catalyst preparations (1) and (2) are characterized in that the content of alkylphenols in the alkali metal catalyst 1
3. 3,3 'according to claim 1, characterized in that it is in the range of 1 to 5 moles per mole and the water content in the catalyst preparation is in the range of 2 to 20% by weight. Of 5,5,5'-tetra-t-butylbiphenol. 3. The catalyst according to claim 2, wherein the weight ratio of alkylphenols to phenol [alkylphenols / phenol] in the catalyst preparation (2) is 70/30 or more. A method for producing 5,5'-tetra-t-butylbiphenol. 4. The method for producing 3,3 ', 5,5'-tetra-t-butylbiphenol according to any one of claims 1 to 3, wherein the alkylphenol is pt-butylphenol.