JPH02180844A - Production of alkylphenols - Google Patents

Abstract

PURPOSE:To industrially and efficiently obtain the objective compounds by adding specific steps and/or omitting intermediate steps in producing the subject compounds from phenols, alcohols and aldehydes under specified conditions in two stages. CONSTITUTION:(i) Phenols are reacted with alcohols and aldehydes in the presence of a catalyst in the fist reaction column 1 to provide alkoxyalkylphenols. (ii) The resultant alkoxyalkylphenols are then catalytically cracked in the presence of hydrogen gas and a catalyst in the second reaction column 5 to produce the subject compounds useful as a raw material for various chemicals. In the afore-mentioned stages, a step (a) for subjecting the reaction product obtained in the above-mentioned stage (i) to evaporation treatment in the first evaporation column 2, further subjecting the overhead product to distillation treatment in the first distillation column 3 and recovering the alcohols and catalyst in a holding drum 4, step (b) for catalytically cracking the product obtained as a bottom product in the evaporation treatment in the first evaporation column 2 in the step (a) in the second reaction column 5 according to the afore-mentioned stage (ii) and/or step (c) for subjecting the cracking reaction product in the above-mentioned stage (ii) to evaporation treatment in the second evaporation column 7, then adding an acid to the overhead product, further subjecting the resultant product to evaporation treatment in the third evaporation column 8 and removing nitrogen components are added to efficiently use the raw materials, improve production efficiency and afford the objective compounds at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing alkylphenols, and more particularly to a method for industrially and efficiently producing alkylphenols.

[Prior art and problems to be solved by the invention] Generally, alkylphenols such as 2,6-di-tert-butyl-4-methylphenol are used as antioxidants, preservatives, and raw materials for other chemical products. It is a useful compound. Such alkylphenols can be used, for example, in the presence of a tertiary amine as a catalyst.
- To produce alkoxyalkylphenols by reacting phenols such as butylphenol with alcohols and aldehydes (see JP-A-63-112529), and then reacting the alkoxyalkylphenols with hydrogen gas and a copper-chromium based catalyst. A method for producing it by catalytic cracking in the presence of is known (see US Pat. No. 3,006,969).

However, the above-mentioned method requires complicated operations, and the resulting alkoxyalkylphenols contain impurities, so that they are not practically satisfactory. Therefore, to date, no industrially advantageous and practically efficient method for producing alkylphenols from phenols via alkoxyalkylphenols has been developed.

[Means to solve the problem]

Therefore, the present inventor conducted extensive research in order to develop an industrially efficient method for producing alkylphenols. As a result, a series of processes for producing alkylphenols,
It has been found that the above object can be achieved by adding a specific step.

The present invention was completed based on this knowledge.

That is, the present invention involves reacting phenols, alcohols, and aldehydes in the presence of a catalyst to produce alkoxyalkylphenols, and then catalytically decomposing the alkoxyalkylphenols in the presence of hydrogen gas and a catalyst to produce alkylphenols. (a) The reaction product obtained by reacting phenols, alcohols, and aldehydes in the presence of a catalyst is evaporated in an evaporation column, and the resulting top product is further distilled to obtain alcohol. The process of recovering the metals and the catalyst.

(1)) The reaction product obtained by reacting phenols, alcohols, and aldehydes in the presence of a catalyst is evaporated in an evaporation column, and the resulting bottom product is then evaporated in the presence of hydrogen gas and a catalyst. and (c) the decomposition reaction product '&J obtained by catalytic cracking in the presence of hydrogen gas and a catalyst is subjected to evaporation treatment in an evaporation column, and then an acid is added to the obtained column top product. The present invention provides a method for producing alkylphenols, which further comprises at least one step of removing nitrogen components by evaporation treatment.

Hereinafter, the manufacturing method of the present invention will be explained with reference to the process diagram shown in FIG.

First, raw material phenols, alcoholic aldehyde Vr, and a catalyst are introduced into the first reaction column 1 and reacted according to the following reaction formula (1) to produce alkoxyalkylphenols.

Cl-1-OR (In the formula, R', R2, and R' are hydrogen or an alkyl group.

It is an alkenyl group or an aralkyl group, and R3 is an alkyl group, an alkenyl group, or an aralkyl group. ) First, as raw material phenols, for example, phenol; 0-cresol; m-cresol; p-cresol; ethylphenol; propylphenol; p-octylphenol; xylenol; p-tert-butylphenol; p-tert-amylphenol. ;o-
5ec-amylphenol; p-nonylphenol; 0
-Phenylphenol; 2,6-diethylphenol:
2,6-di-isopropylphenol; 2,6-sheet
erL-butylphenol; di-tert-amylphenol; di-sec amylphenol and the like can be suitably used.

Moreover, as the alcohol, a saturated or unsaturated aliphatic alcohol having 1 to 20 carbon atoms can be used.

For example, saturated alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol 1 dodecanol-1 alcohol and polyhydric alcohols such as ethylene glycol and glycerin may be appropriately selected and used. Can be done.

However, since the alcohol used as a raw material does not remain in the final product, lower alcohols with low boiling points that are easy to react and recover, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, etc. can be preferably used.

Further, as the aldehydes, saturated and unsaturated aliphatic aldehydes can be used, and these can also be appropriately selected and used depending on the structure of the target compound. For example, formaldehyde, paraformaldehyde.

Acetaldehyde, propionaldehyde, ethoxyacetaldehyde, acrolein, crotonaldehyde,
Examples include hydroxyacetaldehyde.

Further, as a catalyst, various catalysts commonly used in this type of reaction can be used, but it is particularly preferable to use a tertiary amine. This tertiary amine is
For example, trimethylamine; triethylamine; tripropylamine; tributylamine; triamylamine;
Tribenzylamine; triphenylamine, N,N-dimethylethylamine, N,N-dimethyl=n~propylamine; N,N-diethylmethylamine, N,N-diethyl-〇-propylamine; N,N-di Examples include n-propylethylamine.

In the method of the present invention, the blending ratios of various raw materials and catalysts are appropriately determined depending on their types and reaction conditions.
- When butylphenol (hereinafter referred to as DTBP) is used, the aldehyde should be 0.5 to 1% formaldehyde or formalin per 1 mole of DTBP.
The appropriate amount is 0 mol, preferably 1 to 5 mol, and the alcohol is, for example, when methanol is used, D
TBP (7) 1 750 to 2000mf to Morni
l, preferably 100 to 1000 ayj! A range of is appropriate.

Further, the amount of the catalyst is 1 to 200 g, preferably 10 to 1 in the case of triethylamine, per 1 mole of DTBP.
A range of 00g is appropriate.

The reaction conditions in the first reaction tower 1 vary depending on the type and composition of raw materials, but usually the reaction temperature is set at 50 to 200.
°C1 preferably 80-150 °C, natural pressure (
It can be carried out under self-pressure. The reaction time is 0
．． The reaction time is 5 to 20 hours, preferably 1 to 10 hours, and the reaction format can be either a batch type, a semi-batch type, or a 5-continuous type.

The reaction product produced in the first reaction tower 1 is introduced into the first evaporation tower 2 and subjected to evaporation treatment. The processing conditions in the first evaporation column 2 are determined by the reaction products, unreacted raw materials, type of catalyst, or their ratio, but usually the temperature is 50 to 250"C1, preferably 100"C. ~170°C, pressure 1~760 mm11
g, preferably 10 to 2001T1mHg, 1 to
It can be carried out for 10 hours, preferably 2 to 7 hours.

The top product obtained by the evaporation treatment in the first evaporation column 2 is mainly a mixture of the catalyst, the alcohol added in excess, and the water produced by the reaction of two aldehydes. In step (a) of the present invention, this column overhead product is introduced into the first distillation column 3 and subjected to distillation treatment. By distilling this column overhead product in the first distillation column 3, low-boiling components such as catalysts such as tertiary amines and alcohols are separated at the top of the first distillation column 3, and high-boiling components Aldehydes, water, etc. separate at the bottom of the column. As a result, the catalyst and alcohols at the top of the column can be recovered, and if these are recovered in the hold drum 4 and introduced into the first reaction column 1 for reuse, the consumption of raw materials and catalyst can be reduced. area. The recovery of the catalyst and alcohols in the first distillation column 3 can be carried out as appropriate depending on the type of catalyst and alcohols, the component state of the top product of the first evaporation column 2, and the like.

On the other hand, the bottom of the first evaporation column 2 is mainly alkoxyalkylphenols, such as 2,6-tert-butyl-4-methoxymethylphenol;
2,6-di-5ec-butyl-4-methoxymethylphenol; 2,6-diisopropyl-4-methoxymethylphenol; 2゜6-diethyl-4-methoxymethylphenol; 2,6-dimethyl-4-methoxymethyl Phenol; 2,6-dicyclohexyl-4-methoxymethylphenol; 2-methyl-4-methoxymethyl-6
-tart-butylphenol; 2,6-di-tar
Examples include t-butyl-4-ethoxymethylphenol.

In step (b) of the present invention, the bottom material of the first evaporation column 2 is directly introduced into the second reaction column 5 without removing heavy components, and is subjected to the next reaction in the presence of hydrogen gas and a catalyst. Formula (I
Catalytic cracking is performed according to f) to obtain a cracking-reactive product containing alkylphenols.

Reaction formula (n) (In the formula, R', R'', R3, and R' are the same as above.) The catalyst used here may be any of various catalysts that can be used for general hydrogenolysis. Can be used.

Particularly preferred catalysts include copper-chromium-barium catalysts and copper-chromium-barium-manganese catalysts.

When these ternary or quaternary metal catalysts are used, it is preferable that each metal is an oxide. There are no particular restrictions on the proportions of metals in these ternary or quaternary metal catalysts, but in copper-chromium-barium catalysts, copper is usually 20-42% by weight, chromium 17-33% by weight, and barium 2-20% by weight. In copper-chromium-barium-manganese catalysts, copper is usually 15 to 45% by weight.
% by weight, chromium 12-40% by weight, barium 0.5-1
5% by weight, and 0.5-15% by weight of manganese.

There is no particular limit to the amount of this catalyst used, but usually,
The amount of O per 1 kg of the column bottom is in the range of 1 to 100 g, preferably 1 to 50 g. If the amount of catalyst used is small, sufficient catalytic action may not be developed and the yield of the target alkylphenol may decrease. On the other hand, even if it is used in excess, it cannot be expected to improve the yield commensurate with the amount used.

Further, a carrier is not particularly required, but if desired, silica,
Alumina, magnesium, zirconia.

Niobium oxide, doria, boria 2, silica-alumina.

Silica-magnesia, chromia-alumina, alumina
Boria, molypdenor alumina, tungsten oxide-alumina, silica-titania, zeolite, high-silica zeolite, mordenite gallosilicate, iron silicate silicalite, faujasite, crystalline aluminum phosphate, perovskite clay, activated carbon, carbonized fiber, diatom It may also be supported on a material (such as soil).

Additionally, this reaction can be performed using methanol and ethanol.

Alcohols such as isopropanol and pentane.

Aliphatic hydrocarbons such as hexane, heptane, octane, nonane, and decane can be used as solvents.

The amount of these solvents is 200 to 5
000In1, preferably in the range of 500 to 3000d.

The decomposition reaction in the second reaction tower 5 can be carried out under general conditions. That is, the reaction temperature is 80-2
50°C, preferably 100 to 200°C. If this reaction temperature is too low, the reaction will not proceed sufficiently, and
If it is too high, side reactions may occur and the yield of the target product may not be sufficiently increased.

In addition, the pressure of hydrogen gas is 0 to 100 kg/cnlG,
Preferably, it is selected within the range of 10 to 50 kg/cJG.

If the pressure of hydrogen gas is too low, the reaction may not proceed sufficiently, and if it is too high, the result may not be reflected in the yield improvement. It is preferable that the hydrogen used here be sufficiently purified, for example, water electrolysis, water gas denaturation, etc.
Those obtained by various methods such as gasification of petroleum and modification of natural gas can be used. In some cases, a mixed gas of hydrogen gas and an inert gas, such as nitrogen, helium, or argon, may be used. When using a mixed gas, it is preferable to adjust the hydrogen partial pressure to the above hydrogen gas pressure.

The reaction time in the second reaction column 5 is usually 0.65 to 10 hours, preferably 1 to 8 hours. This reaction time is 0.
When the time is shorter than 5 hours, alkylphenols are not sufficiently produced, and even when the time is longer than 10 hours, it tends not to contribute much to improving the yield of alkylphenols.

The reaction format of this second reaction column 5 can be any of a batch type, semi-batch type, and continuous type. In addition, before being introduced into the second reaction tower 5, evaporation treatment is performed in advance according to a conventional method to remove heavy components, leaving only the alkoxyalkylphenols that will be the raw materials for producing the desired alkylphenols, and then subjected to hydrogenolysis. You can also do it.

Next, in step (c) of the present invention, the reaction product (decomposition reaction product) of the second reaction tower 5 is introduced into a filter 6 to separate the catalyst, if necessary, and then the second evaporator tower 7
and perform evaporation treatment.

The evaporation process in this second evaporation tower 7 is usually carried out at a temperature of 5.
0-250°C1, preferably 70-150°C, pressure 1-760mmHg, preferably 10-500mm
This can be carried out under Hg conditions. Through this evaporation treatment, the alkylphenols produced by the hydrogenolysis reaction can be taken out as a bottom product, and the solvent such as alcohol added as a solvent in the second reaction tower 5 can be separated as a top product. . Second evaporation tower 7
The top product is then introduced into the third evaporation column 8, where it is evaporated with acid added thereto. The evaporation process in the third evaporation tower 8 involves the recovery of the solvent added to the second reaction tower 5, and the recovery of the nitrogen added to the first reaction tower 1 as a catalyst and accompanied by the products of each stage. This is carried out for the purpose of removing compounds (tertiary amines or reactants derived therefrom). Acids include sulfuric acid, hydrochloric acid, nitric acid,
Mineral acids such as phosphoric acid and organic acids such as formic acid and acetic acid can be used, and the amount added varies depending on the amount and properties of nitrogen compounds contained in the top of the tower, but nitrogen compounds can be neutralized by a neutralization reaction. It is desirable to add enough to extract it as a salt.

Furthermore, the conditions for the evaporation treatment are set within a range that allows the solvent to be recovered from the kiln. For example, change the temperature to 60-250°C1
Preferably 80-150'C, pressure 1mm11
g~5 kg/cIiT, preferably 10~760
The treatment can be carried out for 0.5 to 10 hours, preferably 1 to 5 hours.

The solvent recovered by the third evaporation tower 8 can be introduced into the second reaction tower 5 again through the hold drum 9, and a portion can be introduced into the first reaction tower 1 as a solvent. This results in
It is possible to reduce the amount of solvent used. Further, by adding an acid and performing evaporation treatment in the third evaporation tower 8, nitrogen compounds can be removed and accumulation of nitrogen compounds in the hydrogenolysis system can be prevented.

On the other hand, the bottom product of the second evaporation column 7 is mainly alkylphenols, which are the target products, but also contains other by-products and unreacted alkoxyalkylphenols. Therefore, by introducing this column bottom product into the second distillation column 10 and subjecting it to distillation treatment, byproducts mainly consisting of heavy components can be separated at the column bottom.

Further, the top product of the second distillation column 10 is purified in the same manner as conventional purification treatment to obtain the desired alkylphenols. In this purification process, for example, water, alcohol, etc. are added to the top of the second distillation column 10, crystallization is performed in the separation column 11, and then the alkylphenols are separated by filtration in the filter 12. Drying [13] This can be done by a method such as drying. Further, the filtrate from the filter 12 is distilled in the third distillation column 14 to separate heavy components such as alcohol from unreacted alkoxyalkylphenols. Can be reused.

Note that the recovery of the catalyst and solvent in the first distillation column 3 and the second evaporation column 8 does not necessarily have to be carried out, and even if the evaporation treatment is performed between the first evaporation column 2 and the second reaction column 5. Alkylphenols can be produced in the same manner, but by carrying out at least one of these, it is possible to reduce production costs and improve production efficiency.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that the apparatus shown in FIG. 1 is used as the apparatus, and the explanation of this embodiment will be made for each apparatus.

a) In a first reaction column with a first reaction column capacity of 300 ml, 2,6-diter
80 g (0.39 mol) of t-butylphenol, 13.9 g of paraformaldehyde, 32 g of ethylamine, and 200 yd of methanol were charged, and the reaction was carried out at 90°C for 7 hours.

After completion of the reaction, gas chromatography analysis of the product revealed that 92% by weight of 2,6-tert-butyl-4-methoxymethylphenol and 4.4'-methylenebis(2,5-tert-butylphenol) is 3
．． The yield was 5% by weight.

b) First evaporation tower The reaction product of the first reaction tower is heated to 210°C in the first evaporation tower.
, 760mm 11g for 1 hour, then 160°CC120
s) Light treatment was carried out for 20 minutes with I. The bottom product after treatment contained 92% by weight of 2,6-di-tert-butyl-4-methoxymethylphenol, and total nitrogen analysis showed that 11
It contained 00 ppm nitrogen.

C) First Distillation Column The top of the first evaporation column was distilled using a concentric precision fractionator (HC-5500F, manufactured by Shibata Kagaku Kikai Kogyo ■) at a top temperature of 65'C and a pressure cuff of 60 mmHg.

The overhead product was a mixture of methanol and triethylamine, and the water content was less than 500% by weight.

Furthermore, as a result of gas chromatography analysis of the column overhead material, the amount of triethylamine in the column overhead material was 31 g.

As a result, most of the triethylamine added as a catalyst to the first reaction tower could be recovered.

d) 94g of the bottom of the second reaction column and the first evaporation column and 0.47g of the copper-chromium catalyst
190 g and methanol were charged into the second reaction tower, hydrogen gas was kept at a constant pressure of 30 kg/c+flG, and 14
The reaction was carried out for 4.5 hours at 0'C.

After the reaction, gas chromatography analysis of the product revealed that 92.5% by weight of 2,6-di-tert-butyl-4-methylphenol and 4,4'methylenebis(2,6-di-tert-butyl-4-methylphenol) were present. -butylphenol) is 3
．． The yield was 6% by weight.

e) Second evaporation tower The mother liquor from which the catalyst in the reaction solution in the second reaction tower was removed with a filter was heated in a second evaporation tower at 80'C, 760mm) for 1 hour, and then at 80°C, 20mm, 11g. Light treatment was performed for 20 minutes.

A total nitrogen analysis of the recovered methanol at the top of the tower revealed that it contained 400 ppm by weight of nitrogen.

f) Add 1 g of sulfuric acid to the top of the second evaporation tower, and make 65"C, 7
Evaporation treatment was performed at 60 mmHg. A total nitrogen analysis of the top product (recovered methanol) of the third evaporation column revealed that the nitrogen content had decreased to below 1 ppm. As a result, most of the nitrogen compounds in the recovered methanol could be removed.

g) The bottom of the second distillation column and the third evaporation column is passed through the second distillation column (single distillation) to 127
Distillation was carried out at 10 mm and 11 g.

71.5 g of 2,6-di-tert-butyl-4-methylphenol (total yield: 83.7 mol%) was obtained from the top of the column. This 2,6-di-tert-butyl-4-methylphenol contained 210 ppm by weight of 2 as an impurity.
□ Contained 6-di-tert-butyl-4-methoxymethylphenol.

Thereafter, a crystallization treatment was performed in the same manner as in the conventional method to purify 2°6-di-tert-butyl-4-methylphenol.

〔Effect of the invention〕

As explained above, the present invention adds a specific step to the conventional manufacturing process or simplifies intermediate steps, thereby improving the efficient use of raw materials by recovering catalysts and solvents, and improving manufacturing efficiency. You can improve your performance. Moreover, by adopting at least one of these steps into a conventional process, an industrially efficient method for producing an alkylphenol neck can be achieved.

Therefore, according to the method of the present invention, it is possible to provide alkylphenols, which are raw materials for various chemical products, at low cost.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an example of the manufacturing process for carrying out the method of the present invention. ■...First reaction tower, 2...First evaporation tower. 3...First distillation column, 4...Hold drum. 5...Second reaction tower, 6...Filter. 7...Second evaporation tower, 8...Third evaporation tower. 9...Hold drum, 10...Second distillation column. 11...Crystallization tower, 12...Filter. 13...Dryer, 14...Third distillation column. 15...Hold Drum Patent Applicant Idemitsu Petrochemical Co., Ltd. Agent Patent Attorney Tamotsu Otani

Claims (1)

[Claims] (1) In producing alkylphenols by reacting phenols, alcohols and aldehydes in the presence of a catalyst to produce alkoxyalkylphenols, and then catalytically cracking the alkoxyalkylphenols in the presence of hydrogen gas and a catalyst, (a) The reaction product obtained by reacting phenols, alcohols, and aldehydes in the presence of a catalyst is evaporated in an evaporation column, and the resulting top product is further distilled to produce alcohols and aldehydes. A step of recovering the catalyst, (b) evaporating the reaction product obtained by reacting phenols, alcohols, and aldehydes in the presence of a catalyst in an evaporation column, and then converting the obtained column bottom to hydrogen gas. and (c) the cracking reaction product obtained by catalytic cracking in the presence of hydrogen gas and a catalyst is evaporated in an evaporation column, and then the resulting column overhead is catalytically cracked. 1. A method for producing alkylphenols, comprising at least one step of adding and further evaporating to remove a nitrogen component.