JPS6023097B2 - Method for producing 2,2'-methylenebis-(4,6-dialkylphenol) - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2,2'-methylenebis(4,6-dialkylphenol) represented by the following general formula.

However, in the formula, R represents a methyl group or an ethyl group, and R2 represents a tertiary-butyl group or a tertiary-amyl group. Generally 2.
2-methylene bis(4,6-dialkylphenol)
(hereinafter referred to as "the compound") is a useful compound that has been used for a long time as an antioxidant in natural and synthetic rubbers, synthetic resins, lubricating oils, etc., and many methods have been proposed for its production. It's here.

For example, US Pat. No. 2,538,355 proposes a method in which hydrochloric acid is used as a catalyst and reacted with formalin in an inert organic solvent such as n-heptane at 60°C or less. However, this method uses an anionic surfactant with a high HLB and acid stability as a dispersant in order to disperse dialkylphenol, which is a raw material for a heterogeneous reaction, into an aqueous layer containing formalin and hydrochloric acid. There is a need to. Furthermore, since this method uses a reaction temperature of 6,000 or less, the resulting compound precipitates out, making it extremely difficult to remove the acid in post-treatment. Another method is to use water as a reaction medium and react with formalin in the presence of an acid (US Pat. No. 233,021).
No. 7, No. 277310, and No. 2796444) were proposed. In this method, the dialkylphenol as a raw material and the compound produced are immiscible in water,
Therefore, as in the method described above, H
Although anionic surfactants with high LB are used, they still require large amounts of acid and long reaction times. Furthermore, in this method, the reaction product often coagulates into large lumps, making it impossible to form a clear frame, so the product can only be obtained in the form of small particles if complicated operating conditions are strictly observed. Therefore, according to the method proposed in Japanese Patent Publication No. 33-1877 as an improved method, water is used as a reaction medium and an anionic surfactant with a high HLB is used together with an inert organic solvent such as n-hebutane, chlorobenzene, or naphtha. It has been reported that by adding 1 to 3% by weight of the product to the reactant, the resulting product can be made into small particles, and the purity and color tone of the product can also be improved. However, all of these methods are not only heterogeneous reactions, but also the product precipitates in the form of particles, so that unreacted dialkylphenol is included inside the particles, and it takes a long time to complete the reaction. As an improved method of this, a method was proposed in Japanese Patent Publication No. 42-235. This method uses an aromatic solvent such as benzene, toluene, or xylene as a reaction solvent, uses paraformaldehyde as a solid as a formaldehyde source, and removes water produced during the reaction by azeotroping with the solvent. Since the reaction system can be kept substantially homogeneous, the reaction time can be shortened to 1/2 to 1/3 of the conventional time, and since the product is dissolved in the solvent, it does not form lumps, resulting in improved yield and purity. It is reported that there has been a significant improvement. However, since this method removes the produced water by azeotropy, formaldehyde distills out and escapes to the separated water layer together with the coexisting water-solvent, resulting in a very low utilization rate of paraformaldehyde, which is twice the theoretical amount. For the first time, theoretical quantities of the compound have been obtained using paraformaldehyde. Furthermore, since this method uses an aromatic organic solvent that easily azeotropes with water, the reaction product is easily dissolved, and the target product cannot be obtained unless the solvent is distilled off. To obtain the product, it must be further recrystallized in another solvent. Furthermore, since all of these methods use a liquid acid catalyst such as sulfuric acid or hydrochloric acid, it is extremely difficult to remove the catalyst from the product.
As a result of various studies, the present inventors found that this reaction is possible with water,
The reaction is significantly inhibited by proton solvents such as alcohol, and when the reaction is carried out in an inert organic solvent, the water produced impedes the progress of the reaction, and unless the water produced is removed, the reaction rate will not proceed by more than 80%. I realized that.

Therefore, as a result of further intensive research on how to remove this reaction product water, we found that by adding a small amount of nonionic surfactant with low HLB and acid stability to the organic solvent, the reaction product water can be removed from the organic solvent. It was found that the reaction was significantly accelerated and the desired product could be obtained quantitatively. Furthermore, at this time, if an aliphatic organic solvent such as n-heptane, iso-octane, or octane is used and a solid acid catalyst is used, after the reaction is completed, the catalyst can be removed by filtration at 75o0 or higher, and the furnace liquid can be cooled. Since the pure product is precipitated, the pure target product can be easily obtained. As described above, according to the method of the present invention, all the problems of the conventional method are solved and the compound can be obtained efficiently.

The HLB of the surfactant used in the method of the present invention is 11.
It is an essential requirement that it be below, and if it is 11 or more, the reaction rate will decrease significantly. In addition, the amount of the surfactant used is preferably 0.5% by weight or more based on the organic solvent, and 0.5% by weight or more based on the organic solvent.
If the amount is less than % by weight, the reaction rate decreases significantly. Actually, from an economic point of view, it is preferable to use about 1% by weight. The inert organic solvent used is 8 per mole of dialkylphenol as a raw material.
An amount of 0 or more is suitable, and an amount less than that is not preferable because products will precipitate during the reaction.

Further, the reaction temperature must be 60q0 or higher, and lower temperatures are not preferred because the product will precipitate. However, when the temperature rises, formaldehyde dissipates out of the system, causing a decrease in the utilization rate of paraformaldehyde.
A temperature range of 95 qo was found to give the best results. Examples of the present invention are shown below.

Example 1 32.8 moles (0.2 mol) of 2-tertiary-butyl-4-methylphenol, 10 moles of Amberlyst 15 (manufactured by Organo) as a catalyst, and 10 moles of Span 80 (nonionic interface manufactured by Kao Atlas) activator with HLB of 4.3) o. After 5 days, 33 times of n-heptane and 3.3 times of paraformaldehyde were charged into a 200-degree flask equipped with a reflux condenser, kept in the temperature range of 85 to 9 years under cooling, and allowed to react for 1 hour.

After the completion of the reaction, the catalyst was separated by passing through a furnace at a temperature of 75q○ or higher, and the furnace liquid was cooled to 10℃ to obtain 2.2methylenebis-(4-methyl-6-tertiary-butylphenol)31
A compound (melting point 131-13y0) was precipitated, and when the solvent was concentrated, an additional 2.7 particles (melting point 130-1320) were precipitated. The yield rate is about 99%. Example 2 2-tertiary-butyl-4-methylphenol 32.8 days, Amberlyst 15 10 days, Nonion L-2 (a nonionic surfactant manufactured by Nissan Chemical Co., Ltd. with an HLB of 9.5)
A 200M flask equipped with a reflux condenser was charged with 0.5 nights of n-heptane, 33 times of paraformaldehyde, and the same operation as in Example 1 was carried out to obtain 2,2-methylenebis(4-methyl- 6-tertiary-butylphenol) 33.7 hours (melting point 131-1330C) was obtained.

The yield rate is about 99%. Example 3 2-Tertiary-butyl-4-methylphenyl 32.8 nights, catalyst Amberlyst 15 recovered in Example 2 for 10 nights, nonion L-2 for 0.5 nights, n-hef.

Example 1
When reacted for 2 hours under the same conditions, 2,2-methylenebis-(4-methyl-6-tert-butylphenol)32
．． 3 yo (melting point 131-13yo) was obtained. The yield rate is 96.6%. Example 4 2-tertiary-butyl-4-methylphenol 32.8 days, Amberlyst 15 5 days, Nonion L-2 0.5 days
Evening, n-hef.

Example 1
Under the same conditions as 2. After reacting for an hour, 33.5 hours of 2,2'-methylenebis(4-methyl-6-tertiary-butylphenol) (melting point 131-13yo) was obtained.
The yield rate is 98.3%. Example 5 2-tertiary-butyl-4-methylphenol was added for 32.8 hours, Amberlyst 15 was added for 10 hours, and Nonion L-2 was added for 0.8 hours.
2 days, n-heptane 33 times, paraformaldehyde 3 times.
3 nights under the same conditions as Example 1. If you react for a long time,
2,2-methylenebis-(4-methyl-6-tertiary-butylphenol) 32.3 nights (melting point 131-133qC
)was gotten.

The yield rate is 95.6%. Example 6 2-tertiary-butyl-4-methylphenol 32.8 hours, Amberlyst 15 10 hours, Nonion L-2 0.8 hours.
5 days, isooctane 33 days, paraformaldehyde 3 days.
3 nights under the same conditions as Example 1. If you react for a long time,
2,2'-methylenebis(4-methyl-6-tertiary-
butylphenol) 33.7yo (melting point 131-13yo)
)was gotten.

The yield rate is about 99%. Example 7 2-tertiary-butyl-4-ethylphenol 35.6 hours, Amberlyst 15 10 hours, Nonioso L-2 0.
5 days, n-heptane 33 days, paraformaldehyde 3 days.
3 nights under the same conditions as Example 1. If you react for a long time,
2,2-methylenebis(4-ethyl-6-tertiary-butylphenol) 35.7 hours (melting point 121-1240C
)was gotten.

The yield rate is about 97%. Example 8 2-tertiary-butyl-4-methylphenol 32.8 days, Amberlyst 15 10 days, Nonion L-2 0.8 days.
5 days, 20 days of toluene and 3.3 days of paraformaldehyde were charged into a 200' flask equipped with a reflux condenser.
The reaction was carried out at 0 to 90oC for 2.5 hours, and after the reaction was completed, toluene was removed, and 60% isopropanol was added for 40 minutes.
000 to dissolve the product and then cool to 1000 to form 2,2-methylenebis(4-methyl-6-tertiary).
-butylphenol) will precipitate out.

When this is passed through a furnace, it becomes 33.0 minutes (melting point 131-133℃).
was gotten. The yield rate is 97%. Example 92
- tertiary-amyl-4-methylphenol 35.6 hours,
Amber List 15 for 10 evenings, Nonion L-2 for -0.
5 days, n-hebutane 33 days, paraformaldehyde 33 days
When reacting for 1.5 hours under the same conditions as in Example 8, 2.
2-methylenebis-(4-methyl-6-tertiary-amylphenol) 35.7 hours (melting point 72.8-75.000
)was gotten.

The yield rate is 97%. Example 10 2-tertiary-amy-4-methylphenol 35.6 hours, Amberlyst 15 10 hours, Nonion L-2 0.
5 days, n-hexane 33 days, paraformaldehyde 3 days.
The reaction temperature was 65-6800℃ for 3 nights under the same conditions as Example 8.
2,2-methylenebis(4-methyl-tertiary-amylphenol) 34.3
An aqueous solution (melting point 72.8-75.0°C) was obtained.

The yield rate is 93.2 evenings. Comparative Example 1 2-3-tert-butyl-4-methylphenol 32.8 hours,
Example: Amberlyst 15 for 10 days, Nonion S-40 (a nonionic surfactant manufactured by NOF Corporation with HLB of 18.2) for 5 days, n-heptane for 33 days, and paraformaldehyde for 3.3 days. When reacted for 3 hours under the same conditions as in 1, 2,2-methylenebis-(4-methyl-6-tertiary butylphenol) was obtained for 28.3 hours (melting point 130-1320).
was gotten.

The yield was 83%. Comparative example 2 2-tert-butyl-4-methylphenol 32.89,
Amber List 15 on 10th evening, Nonion ST-221 (
A nonionic surfactant manufactured by NOF Corporation with an HLB of 14.
9), 33 days of n-hebutane, and 3.3 days of paraformaldehyde were reacted for 3 hours under the same conditions as in Example 1, resulting in 2,2-methylene piso (4-methyl-6-
tertiary butylphenol) 28.5 hours (melting point 130-1
32qo) was obtained.

The yield was 83.7%. Comparative Example 3 2-tert-butyl-4-methylphenol 32.8 hours,
When Amberlyst 15 was reacted for 10 days, zoda dodecylbenzenesulfonic acid 0.5 days, n-heptane 33 days, and paraformaldehyde 3.3 days were reacted for 3 hours under the same conditions as in Example 1, 2,2-methylenebis-(4-methyl- 6-tertiary butylphenol) (melting point 130-130) was obtained.

Claims (1)

[Claims] 1. When producing 2,2'-methylenebis-(4,6-dialkylphenol) by converting dialkylphenol to methylenebis with paraformaldehyde in an inert organic solvent using an ion exchange resin as a catalyst, A method for producing 2,2'-methylenebis-(4,6-dialkylphenol), which comprises adding a small amount of a nonionic surfactant having an HLB of 11 or less and reacting in a temperature range of 65 to 100C. 2. The method for producing 2,2'-methylenebis-(4,6-dialkylphenol) according to claim 1, wherein the amount of the organic solvent is 80 ml or more, preferably 80 ml to 200 ml, per mole of dialkyl phenol as a raw material. . 3
Claim 1, wherein the amount of surfactant is 0.5% or more, preferably 0.75 to 1.5% by weight based on the organic solvent.
A method for producing 2,2'-methylenebis-(4,6-dialkylphenol) as described in 2. 4 The o-position of the alkyl group of dialkylphenol is the 3rd
2,2'-methylenebis-(4,6-dialkylphenol) according to claim 1, which is a class-butyl group or a tertiary-amyl group, and the p-position is a methyl group or an ethyl group. Manufacturing method.