JPH04288067A - Epoxidized 1-methyltetrahydrobenzyl alcohol and its production - Google Patents

Abstract

PURPOSE:To provide a modified epoxidized tetrahydrobenzyl alcohol and a process for the industrial production of the compound. CONSTITUTION:The epoxidized 1-methyltetrahydrobenzyl alcohol of formula I. The compound can be produced by epoxidizing 1-methyltetra-hydrobenzyl alcohol of formula II with an oxidizing agent (organic peracid or organic peroxide). The objective epoxidized 1-methyltetrahydrobenzyl alcohol can be produced on an industrial scale in high yield by this process.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides epoxidized 1-
This invention relates to methyltetrahydrobenzyl alcohol and its manufacturing method.

In recent years, epoxy compounds have become increasingly useful in a wide variety of fields, including tetrahydrobenzyl alcohol.
Epoxidized tetrahydrobenzyl alcohols obtained by epoxidizing alicyclic unsaturated compounds such as alcohols have been gaining importance.

Epoxidized tetrahydrobenzyl alcohol
Epoxidized 1-methyltetrahydrobenzyl alcohol, which is an analogue of the alcohol, can be polymerized to give a polyether compound having hydroxyl and methyl groups as side chains. Furthermore, it is a useful substance used as a diluent for epoxy resins.

0004

BACKGROUND OF THE INVENTION No known literature describes a method for producing epoxidized 1-methyltetrahydrobenzyl alcohol.

[0005]

OBJECTS OF THE INVENTION The object of the present invention is to provide a method for industrially producing epoxidized 1-methyltetrahydrobenzyl alcohol, which is a modified product of epoxidized tetrahydrobenzyl alcohol. The purpose is to find out.

[0006]

OBJECTS OF THE INVENTION The object of the present invention is to produce an industrially producible epoxidized 1-methyltetrahydrobenzyl alcohol.
The goal is to find a way to produce the same.

[0007]

[Means for Solving the Problems] As a result of extensive research aimed at providing a method that can meet the above-mentioned needs, the present inventors have found that 1-methyltetrahydrobenzyl alcohol is epoxidized using an oxidizing agent. As a result, a method for producing epoxidized 1-methyltetrahydrobenzyl alcohol in high yield and high purity was discovered, and the present invention was completed.

The method for producing the epoxidized 1-methyltetrahydrobenzyl alcohol represented by formula 1 according to the present invention will be described in detail below.

The starting material for the reaction, 1-methyltetrahydrobenzyl alcohol represented by the above chemical formula 2, is a colorless and transparent liquid, and is used as an intermediate material for epoxy resins, inks, paints, and adhesives.

It is produced industrially by hydrogenating 1-methyltetrahydrobenzaldehyde in the presence of a catalyst.

The oxidizing agent that can be used may be any oxidizing agent as long as it can epoxidize unsaturated bonds, such as performic acid, peracetic acid,
organic peracids such as perpropionic acid and m-chloroperbenzoic acid;
Examples include hydroperoxides such as tert-butyl hydroperoxide, cumyl hydroperoxide, tetralyl hydroperoxide, and diisopropylbenzene hydroperoxide, and hydrogen peroxide.

Among these, organic peracids are most preferred in terms of industrial processes.

A catalyst may be used together with the oxidizing agent. For example, in the case of an organic peracid, an alkali such as sodium carbonate or an acid such as sulfuric acid may be used as the catalyst.

Similarly, in the case of hydroperoxide, a compound with known catalytic ability such as molybdenum hexacarbonyl is used, and in the case of hydrogen peroxide, a compound with known catalytic ability such as a mixture of tungstic acid and caustic soda is used in combination. I can do it.

[0015] The reaction is carried out continuously or batchwise, but in the case of continuous reaction, a piston flow type is preferred.

In the case of a batch method, a semi-batch method in which the organic peracid is successively charged is preferred. When carrying out the reaction batchwise, first, a predetermined amount of 1-methyltetrahydrobenzyl alcohol is charged into a reaction vessel, a catalyst and a stabilizer are dissolved therein as required, and an oxidizing agent is dropped into this. I will do it.

The molar ratio between the oxidizing agent and 1-methyltetrahydrobenzyl alcohol is theoretically 1, but as in the present invention, it is actually in the range of 0.1 to 10, preferably 0.5.
-2, more preferably 0.8-1.5.

[0018] It is preferable that the molar ratio of the oxidizing agent and 1-methyltetrahydrobenzyl alcohol is greater than 10 in terms of the conversion rate of 1-methyltetrahydrobenzyl alcohol, shortening the reaction time, and reducing loss due to polymerization. Excessive oxidizing agent causes a side reaction, decreases the selectivity of the oxidizing agent, and recovering unreacted oxidizing agent is undesirable because a large amount of cost is required for recovery.

On the other hand, when the molar ratio of the oxidizing agent and 1-methyltetrahydrobenzyl alcohol is 0.1 or less, the conversion rate and selectivity of the oxidizing agent are high, and side reactions of the product caused by the oxidizing agent are prevented. Although this method is preferable in this respect, it has drawbacks such as the large expense required to recover unreacted 1-methyltetrahydrobenzyl alcohol.

The reaction temperature is preferably below the upper limit so that the epoxidation reaction takes precedence over the decomposition reaction of the oxidizing agent; for example, it is preferably 70°C or below for peracetic acid, and 150°C or below for tert-butyl hydroperoxide.

If the reaction temperature is low, it will take a long time to complete the reaction, so it is preferable to carry out the reaction at a temperature higher than the lower limit of 0°C for peracetic acid and 20°C for tert-butyl hydroperoxide. Also, during epoxidation, side reactions occur in which epoxy groups are consumed by organic acids, alcohols, and water due to by-products from oxidizing agents, so the temperature range that reduces the amount of side reactions is determined by the above-mentioned temperature range. Choose from and carry out the reaction.

Although the process according to the invention generally operates under normal pressure, the process according to the invention can also be carried out under elevated or reduced pressure.

[0023]Although the reaction can be carried out without a solvent,
The presence of a solvent is preferable because it has effects such as lowering the viscosity of the reaction crude liquid and stabilizing it by diluting the oxidizing agent.

Solvents used include aromatic compounds such as benzene, toluene and xylene, halides such as chloroform, dimethyl chloride, carbon tetrachloride and chlorobenzene, ester compounds such as ethyl acetate and butyl acetate, acetone and methyl. Ketone compounds such as isobutyl ketone, ether compounds such as 1,2-dimethoxyethane, etc. can be used.

1-Methyltetrahydrobenzyl alcohol
It is desirable to use a solvent in an amount of 0.5 to 6 times the volume of the solvent.

When the amount is less than 0.5 times, the stabilizing effect of diluting the oxidizing agent is small, resulting in a decrease in yield.

[0027] Even if the amount is increased by more than 6 times, the effect remains the same and recovery of the solvent requires a large amount of cost, so it is wasteful. Further, it is usually preferable to blow nitrogen gas into the system in order to avoid the formation of an explosive mixture within the system. The blowing position may be either directly into the liquid or into the gas phase.

[0028] The amount of blowing can be arbitrarily selected, but if it is too large, solvent loss will occur.

The end point of the reaction is preferably confirmed by the concentration of the remaining oxidizing agent or by gas chromatography. The epoxidation product reaction crude liquid obtained in the reaction can be purified by distillation of low-boiling components such as solvents, low-boiling substances, unreacted raw materials, and catalysts, neutralization, and treatment with adsorbents and ion exchange resins. .

[0030] If a final product of usable quality can be obtained without purification, it can be omitted.

In particular, when an organic peracid is used as an oxidizing agent, removing low-boiling components without neutralizing the crude reaction solution may cause ring-opening of the epoxy group of 1-methyltetrahydrobenzyl alcohol by the organic acid, or Since cyclization with methylol groups increases loss, it is preferable to neutralize before removing low-boiling components.

Examples of the alkaline aqueous solution used for neutralization include NaOH, KOH, K2 CO3, Na2 CO
Solutions such as 3, NaHCO3, KHCO3, NH3, etc. can be used, the concentrations thereof being freely selectable within wide limits.

From the viewpoint of liquid separation properties or loss, it is desirable to use an aqueous NaOH solution or an aqueous Na2 CO3 solution.

In the neutralization water washing step, it is important to neutralize and remove the organic acid as well as remove the remaining organic peracid in order to stably operate the next low boiling point removing step.

[0035] Therefore, the amount of alkali used is preferably 0.5 to 3 times, preferably 0.8 to 1.5 times, in equivalent ratio to the amount of organic acid in the crude reaction solution. It is not economical to increase the amount more than necessary.

Further, if the equivalence ratio is lowered more than necessary, it is not a good idea because a large amount of water is required to remove the organic acid, and the loss of solvent and the like to the lower water layer also increases.

If the bottoms are made into a product by removing low-boiling components without washing with water after neutralization, neutralized salts will remain in the product, so it is desirable to wash with water after neutralization.

[0038] Neutralization and water washing are preferably carried out at a temperature range of 10 to 90°C, preferably 10 to 50°C.

It is also desirable to blow nitrogen gas during neutralization washing to avoid the formation of an explosive mixture.

[0040] A thin film evaporator or the like is preferably used to remove low-boiling components from the reaction crude liquid that has been neutralized or washed with water. The heating temperature in the low-boiling removal step is preferably 50 to 180°C, preferably 80 to 100°C.

Although the pressure can be arbitrarily selected depending on the physical properties of the low-boiling components, it is common to operate under reduced pressure in relation to the heating temperature.

Furthermore, in order to avoid the formation of an explosive mixture within the system or to facilitate the distillation of low-boiling components, nitrogen is usually blown into the system.

The blowing position can be selected arbitrarily, but it is usual to blow from the line where the bottom liquid is distilled off.

The amount of blowing can be selected arbitrarily, but the upper limit depends on the capacity of the vacuum system, whether the bottom liquid flows down stably, or the recovery loss when collecting the distilled low-boiling components with a condenser. It is naturally limited from the perspective of

The bottom liquid obtained in this way has a purity of 95 to 96%, which is equivalent to a product, but it is slightly cloudy, and high-boiling components are removed in order to obtain a product of even higher purity.

[0046] The high-boiling removal step is carried out in the same manner as the low-boiling removal step, but generally the degree of pressure reduction or heating temperature is further increased to obtain a product as a distillate.

The material of the apparatus to which the manufacturing method of the present invention can be applied is preferably stainless steel or glass-lined steel, but iron or the like may also be used.

[0048] The effects of the present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.

[Example 1] After adding 866 g of 1-methyltetrahydrobenzyl alcohol and 3200 g of ethyl acetate to a reactor with an internal capacity of 8 L equipped with a jacket for water cooling,
1965 g of a 30% solution of peracetic acid in ethyl acetate was added dropwise over 4 hours. During the dropping, the temperature of the hot water flowing through the jacket was adjusted so that the reaction temperature was maintained at 30°C.

Even after the dropwise addition was completed, the temperature of the reaction solution was maintained at 30° C. for 4 hours to complete the reaction.

1-Methyltetrahydrobenzyl alcohol
The conversion rate based on alcohol is 97%, the selectivity based on epoxy 1-methyltetrahydrobenzyl alcohol is 97%, and the yield is 94%.
%Met.

After cooling 5935 g of the reaction crude liquid to room temperature, 2
After adding 2057 g of 0% NaOH aqueous solution and stirring for 1 hour,
Let stand for 0 minutes to separate the liquids.

After separation, low-boiling components of the upper layer liquid were removed.

[0054] Removal of low-boiling components was carried out using a glass Smith type thin film evaporator at a pressure of 150 Torr and a heating temperature of 90 to 95.
℃, and 50 Nl/Hr of nitrogen gas was charged from the bottom liquid distillation line. High-boiling components were also removed using a glass Smith type thin film evaporator under conditions of a pressure of 2 Torr and a heating temperature of 150°C.

As a result of gas chromatography analysis, the purity of the product was 97%.

The elemental analysis values of this product are as follows.

[Example 2] Example 1 except that the reaction temperature was 25°C.
The same operation was performed.

Claims (2)

[Claims] 1. Epoxidized 1-methyltetrahydrobenzyl alcohol represented by the following formula 1. [Chemical formula 1] 2. Epoxidized 1-methyltetrahydrobenzyl alcohol represented by the following chemical formula 2, which is obtained by epoxidizing the 1-methyltetrahydrobenzyl alcohol represented by the above chemical formula 1 with an oxidizing agent. Method for producing benzyl alcohol. [Case 2]