JP2910299B2 - Purification method of bisphenol monoester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the following formula (I):

[0002]

Embedded image

(Wherein R ¹ represents hydrogen or an alkyl group having 1 to 3 carbon atoms, R ² and R ³ each independently represent an alkyl group having 1 to 5 carbon atoms, and R ⁴ represents an alkyl group having 1 to 5 carbon atoms. 3 represents an alkyl group, an alkenyl group having 2 to 4 carbon atoms or a phenyl group).

[0004]

BACKGROUND OF THE INVENTION Bisphenol monoesters represented by the above formula (I) include, for example, butadiene rubber (BR), styrene / butadiene copolymer rubber (SBR), styrene / butadiene block copolymer rubber or resin (SBS). It is a compound useful as a thermal degradation inhibitor during the production process and processing of the base polymer, or as a stabilizer for various synthetic resins such as polyolefins such as polyethylene and polypropylene.

The bisphenol monoesters of the formula (I) are generally prepared by reacting the corresponding 2,2'-alkylidene bisphenol with the corresponding carboxylic acid, carboxylic acid halide or carboxylic anhydride. . As a method for purifying such bisphenol monoester, for example, a method of recrystallization using petroleum ether or n-hexane as described in Examples 11 and 12 of U.S. Pat. No. 3,984,372, JP-A-56-6132
No. 3, JP-A-59-144733 and JP-A-63-50
As described in Examples of JP-A No. 53, the solvent such as toluene or N, N-dimethylacetamide used in the reaction is partially or completely distilled off, and toluene or n-
A method of adding hexane for purification is known.

[0006]

However, in these methods, since the difference in solubility between the target bisphenol monoester and impurities in the crude product to be purified is small, the purification effect is low and the quality of the target product is low. Not always enough. Furthermore, when the solvent is recovered for economic reasons, the production equipment becomes complicated, and thus the production on an industrial scale is not always satisfactory.

The present inventors have provided a solution to this point,
As a result of intensive studies to develop an industrially satisfactory purification method, by crystallization using a specific mixed solvent,
The present inventors have found that the desired product of excellent quality can be obtained in high yield and economically, and have led to the present invention.

[0008]

That is, the present invention provides a process for purifying a crude product of the bisphenol monoester represented by the above formula (I), wherein the first product is selected from aromatic hydrocarbons having 6 to 12 carbon atoms. And a second solvent selected from alcohols having 1 to 8 carbon atoms and aliphatic nitriles having 2 to 3 carbon atoms, and the desired bisphenol monoester is crystallized from this mixed solvent. Provide a way to

The bisphenol monoester represented by the formula (I) to be purified in the present invention is usually 2,2'-alkylidenebis (4,6
-Dialkylphenol) and a carboxylic acid or a derivative thereof. Also, 2,2'-alkylidenebis (4,6-dialkylphenol) as a raw material can be produced by condensing the corresponding 2,4-dialkylphenol with aldehydes.

The alkyl group represented by R ¹ in the formula (I) includes methyl, ethyl, n-propyl and isopropyl. R ¹ is preferably hydrogen or methyl. Examples of the alkyl group represented by R ² and R ³ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl and the like. Particularly, R ³ is preferably an alkyl group having a tertiary carbon, that is, tert-butyl or tert-pentyl. Examples of the alkyl group represented by R ⁴ include methyl,
Ethyl, n-propyl and isopropyl;
Examples of the alkenyl group represented by R ⁴ include vinyl, isopropenyl, 1-propenyl, 1-butenyl and the like. R ⁴ may also be phenyl.

Among the compounds of the formula (I), compounds in which R ⁴ is an alkenyl group are preferably used as stabilizers for various polymers. Preferred specific examples of such bisphenol monoester include the following compounds.

2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-
Pentylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl methacrylate, 2- (2-hydroxy-3,5 -Di-t-pentylbenzyl) -4,6-di-t-pentylphenyl acrylate, 2,4-di-t-butyl-6- [1-
(3,5-di-t-butyl-2-hydroxyphenyl)
Ethyl] phenyl acrylate, 2,4-di-t-butyl-6- [1- (3,5-di-t-butyl-2-hydroxyphenyl) ethyl] phenyl methacrylate,
2,4-di-tert-butyl-6- (3,5-di-tert-butyl-2-hydroxybenzyl) phenyl acrylate, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy- 5-methylbenzyl) -4-methylphenyl
Acrylate, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl methacrylate, 2-tert-butyl-6- [1
-(3-t-butyl-2-hydroxy-5-methylphenyl) ethyl] -4-methylphenyl acrylate,
2-tert-butyl-6- [1- (3-tert-butyl-2-hydroxy-5-methylphenyl) propyl] -4-methylphenyl acrylate, 2-tert-butyl-6- (3
-T-butyl-5-ethyl-2-hydroxybenzyl)
-4-ethylphenyl acrylate, 2-t-butyl-6- [1- (3-t-butyl-2-hydroxy-5-
Propylphenyl) ethyl] -4-propylphenyl
Acrylate, 2-t-butyl-6- [1- (3-t-
Butyl-2-hydroxy-5-isopropylphenyl)
[Ethyl] -4-isopropylphenyl acrylate.

In the present invention, such a bisphenol monoester is purified by crystallization. At this time, a specific mixed solvent as a crystallization solvent, that is, a first solvent selected from aromatic hydrocarbons having 6 to 12 carbon atoms and a first solvent having 1 carbon atom
A mixed solvent with a second solvent selected from alcohols having from 8 to 8 and aliphatic nitriles having from 2 to 3 carbon atoms is used.

Examples of the first solvent, which is an aromatic hydrocarbon having 6 to 12 carbon atoms, include benzene, toluene, xylene, ethylbenzene, cumene, cymene and chlorobenzene. These aromatic hydrocarbons may be used alone as the first solvent constituting the mixed solvent in the present invention, or may be used in combination of two or more kinds. Is used. Among these aromatic hydrocarbons, toluene or xylene is particularly preferably used, and xylene is particularly preferable.

On the other hand, among the second solvents, alcohols having 1 to 8 carbon atoms include, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol and the like. n-octanol, 2-ethylhexanol,
Cyclohexanol and the like can be mentioned. Examples of the aliphatic nitriles having 2 to 3 carbon atoms include acetonitrile and propionitrile. These alcohols and aliphatic nitriles can be used alone or in combination of two or more as the second solvent constituting the mixed solvent in the present invention. Among these second solvents, alcohols are preferable, and particularly, methanol which is inexpensive and easily recoverable is preferably used.

Of the mixed solvents used in the present invention, aromatic hydrocarbons, which are the first solvents, are usually used as a reaction solvent in the production of bisphenol monoester, and the solubility of bisphenol monoester is high. Acts as a solubilizer in the precipitation process. Therefore, when an aromatic hydrocarbon is used as a reaction solvent, the process can proceed to the crystallization step in a solution state in which the aromatic hydrocarbon remains. In the crystallization process, the alcohol or aliphatic nitrile as the second solvent controls the solubility of the bisphenol monoester in the first solvent to improve the yield and the purification effect, or to the crystallizer. It is used for the purpose of preventing scaling of the data. When the first solvent or the second solvent is used alone, the quality or the yield of the target product is reduced. In particular, when the second solvent is used alone, the monoesterification reaction may occur. Since it is necessary to distill the used aromatic hydrocarbon solvent out of the system, it is not preferable in industrial scale production for economic reasons.

As described above, the bisphenol monoester to be crystallized in the present invention is a solution of a reaction mixture containing the aromatic hydrocarbon, particularly when an aromatic hydrocarbon is used as a reaction solvent in the monoesterification step. Or a crystallized product after removing the solvent from the reaction product. In particular, in production on an industrial scale, it is preferable that the bisphenol monoester and the impurities are dissolved in the aromatic hydrocarbon used as the reaction solvent, and the second solvent is added thereto to perform crystallization.

In the present invention, a first solvent is added to the bisphenol monoester represented by the above formula (I).
It is preferable to use about 5 to 150% by weight. The second solvent is preferably used at a mixing ratio of about 0.3 to 4 times the weight of the first solvent. If the amounts of the first solvent and the second solvent are out of this range, the quality and yield of the target product may be lowered, or scaling to the crystallizer may be caused, which is not preferable.

The crystallization operation in the present invention is usually carried out by first
The solvent alone is used to completely dissolve the crude product at or below the boiling point, and then a second solvent is added,
If necessary, a seed crystal serving as a crystal nucleus is added, and the mixture is gradually cooled to precipitate crystals. In some cases, the first solvent and the second solvent are used simultaneously,
The crude product can be dissolved therein for crystallization. Furthermore, when an aromatic hydrocarbon solvent is used in the reaction step, the concentration of the bisphenol monoester is increased by removing a predetermined amount of the solvent by distillation or the like from the solution of the reaction mixture or from the solution. The same operation as described above can also be performed by adding the second solvent. The precipitated crystals are
The target purified product is obtained by separating from the mother liquor by filtration or the like, washing and drying.

[0020]

EXAMPLES The present invention will be described in more detail with reference to specific reference examples and examples, but the present invention is not limited thereto. In addition,% in the following examples
Parts and parts are by weight unless otherwise specified.

Reference Example 1 A reaction vessel equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device was charged with 2,4-di-t-pentylphenol.
4.4 parts, xylene 20 parts, anionic surfactant 4.7
9.5 parts of 78% concentrated sulfuric acid and 77.1 parts of a 30% aqueous solution of acetaldehyde, and stirred at 90 to 100 ° C.
The reaction was carried out for 7 hours while maintaining the temperature range. After the completion of the reaction, 360 parts of xylene was added, the aqueous layer was separated and removed, and then washed with water until the organic layer became neutral.
Under reduced pressure of about 200 mmHg, water was distilled out of the system while refluxing the solvent. After cooling the obtained condensed mixture, 44.8 parts of acrylic acid and 129.0 parts of triethylamine were charged therein, the air in the reactor was replaced with nitrogen, and 63.4 parts of phosphorus oxychloride was added dropwise, and the mixture was kept at 40 ° C for 1 hour. Thereafter, the organic layer was washed with water until neutral, and the solvent was completely distilled off under reduced pressure to obtain crystalline 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl). Ethyl)-
252.5 parts of a distillation residue containing 4,6-di-t-pentylphenyl acrylate was obtained. Analysis of this distillation residue showed that the monoester was 87.5% and the other by-products were 1%.
It was confirmed that it contained 2.2% and unreacted substances 0.2%.

Reference Example 2 Instead of acrylic acid in Reference Example 1, methacrylic acid 5
The same operation as in Reference Example 1 was carried out except that 3.5 parts was used, to give crystalline 2- [1- (2-hydroxy-3,5-di-t-
[Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl 281.4 parts of a distillation residue containing methacrylate was obtained. Analysis of the distillation residue showed that the monoester was 87.0%, the unreacted substance was 0.2%, and the other by-products were 12.
It was confirmed that 7% was contained.

REFERENCE EXAMPLE 3 In the same reaction vessel as in Reference Example 1, 164.3 parts of 2-t-butyl-4-methylphenol, 80 parts of xylene, 1.4 parts of anionic surfactant, 0.3 parts of 96% concentrated sulfuric acid and 37 parts of 37 parts 45.6 parts of a 5% aqueous formaldehyde solution, 90-95 ° C
The reaction was carried out for 3 hours while maintaining the temperature range. After completion of the reaction, 89 parts of xylene was charged, and the same post-treatment and reflux dehydration as in Reference Example 1 were performed. After cooling the reaction solution, add acrylic acid
35.0 parts and 105.7 parts of triethylamine were charged, and the air in the reaction vessel was replaced with nitrogen.
6.4 parts were added dropwise, and the mixture was further kept at 80 ° C. for 1 hour. Thereafter, the same operation as in Reference Example 1 was performed to obtain crystalline 2-t-
Butyl-6- (3-tert-butyl-2-hydroxy-5-
190.8 parts of a distillation residue containing (methylbenzyl) -4-methylphenyl acrylate was obtained. During the distillation residue, monoester 85.5%, diester 4.5%, unreacted 2.9
% And other by-products 7.1%.

Reference Example 4 Instead of acrylic acid in Reference Example 3, methacrylic acid 4
The same operation as in Reference Example 3 was performed except that 2.3 parts were used.
Crystalline 2-t-butyl-6- (3-t-butyl-2-
197.0 parts of a distillation residue containing (hydroxy-5-methylbenzyl) -4-methylphenyl methacrylate were obtained. During the distillation residue, 92.5% of monoester and 3.3% of unreacted product
% And by-products of 4.2%. No diester was detected.

Reference Example 5 Except that 206.3 parts of 2,4-di-t-butylphenol was used instead of 2,4-di-t-pentylphenol in Reference Example 1, and toluene was used instead of xylene as a solvent. The same operation as in Reference Example 1 was performed to obtain crystalline 2,4-di-t-butyl-6- [1- (3,5-di-t
-Butyl-2-hydroxyphenyl) ethyl] phenyl acrylate was obtained in an amount of 231.1 parts. In this distillation residue, 97.0% of monoester and 0.5 of unreacted material
% And 2.4% of by-products.

Example 1 50 parts of the distillation residue obtained in Reference Example 1 was dissolved in 9 parts of xylene at 85 ° C., and 22.5 parts of methanol was gradually added under stirring, and 0.1 part of seed was added at 55 ° C. Crystals were charged. Thereafter, the solution was kept at a temperature in the range of 55 to 50 ° C. for 1 hour to precipitate crystals, and further cooled gradually to 10 ° C., and the crystals obtained at the same temperature were filtered and washed with methanol. after that,
Drying at 60 ° C. under reduced pressure gives 2- [1- (2-hydroxy-3,5-di-t) as white crystals at a melting point of 119 to 121 ° C.
-Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate was obtained in an amount of 40.5 parts.

Examples 2 to 3 The same operation as in Example 1 was carried out except that isopropanol was used in Example 2 and acetonitrile was used in Example 3, instead of methanol in Example 1. I got

Example 4 The same operation as in Example 1 was carried out except that toluene was used instead of xylene in Example 1, to obtain a target white crystal.

Example 5 The same operation as in Example 1 was carried out except that 50 parts of the distillation residue obtained in Reference Example 2 was used, and that xylene was changed to 8 parts and methanol was changed to 24 parts. 2- [1- (2-hydroxy-3,5-di-t) in the form of white crystals at
-Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl methacrylate (39.8 parts) was obtained.

Example 6 After dissolving 50 parts of the distillation residue obtained in Reference Example 3 in 11 parts of xylene at 110 ° C., the mixture was cooled to 85 ° C. with stirring, and 0.1 part of a seed crystal was obtained at the same temperature. I put it in. Crystals were precipitated while gradually cooling, and 36 parts of methanol was added at 50 ° C., further cooled to 20 ° C., and filtered at the same temperature. After washing with methanol, drying under reduced pressure at 60 ° C.
2-t-butyl-6- (3
-T-butyl-2-hydroxy-5-methylbenzyl)
41.0 parts of 4-methylphenyl acrylate were obtained.

Examples 7 and 8 Instead of methanol in Example 6, n-
The same operation as in Example 6 was performed, except that butanol and acetonitrile in Example 8 were used, to obtain a target white crystal.

Example 9 The same operation as in Example 6 was carried out except that toluene was used instead of xylene in Example 6, to obtain a target white crystal.

Example 10 The same operation as in Example 6 was carried out except that 50 parts of the distillation residue obtained in Reference Example 4 was used, and white crystalline 2-t-butyl-6 with a melting point of 144 to 146 ° C. -(3-t-butyl-2-
43.7 parts of (hydroxy-5-methylbenzyl) -4-methylphenyl methacrylate were obtained.

Example 11 After dissolving 50 parts of the distillation residue obtained in Reference Example 5 in 65 parts of toluene at 100 ° C., it was gradually cooled with stirring to precipitate crystals, and methanol was added at a temperature of 80 ° C. Then, the mixture was cooled to 20 ° C., and the obtained crystals were filtered at the same temperature. After washing with methanol, 60 ° C under reduced pressure
And dried at a melting point of 190 to 192 ° C. to give white crystalline 2,4-di-tert-butyl-6- [1- (3,5-di-t).
-Butyl-2-hydroxyphenyl) ethyl] phenyl acrylate (45.1 parts).

The crystallization results obtained in Examples 1 to 11 are summarized in Table 1.

[0036]

[0037]

According to the present invention, the objective bisphenol monoester of the formula (I) can be efficiently and economically produced with high purity and high yield. Therefore, the method of the present invention is useful as a purification method for producing the bisphenol monoester represented by the above formula (I) on an industrial scale.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Shinichi Yago 3-1-198 Kasuganaka, Konohana-ku, Osaka Sumitomo Chemical Co., Ltd. (56) References JP-A-57-95941 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) C07C 69/16 C07C 67/52 C07C 69/28 C07C 69/54

Claims (4)

(57) [Claims] (1) The following formula: (Wherein, R ¹ represents hydrogen or an alkyl group having 1 to 3 carbon atoms, R ² and R ³ each independently represent an alkyl group having 1 to 5 carbon atoms, and R ⁴ represents an alkyl group having 1 to 3 carbon atoms. Group,
Represents an alkenyl group having 2 to 4 carbon atoms or a phenyl group)
In purifying the bisphenol monoester represented by the formula, a first solvent selected from aromatic hydrocarbons having 6 to 12 carbon atoms, an alcohol having 1 to 8 carbon atoms and an aliphatic nitrile having 2 to 3 carbon atoms A method for purifying a bisphenol monoester represented by the above formula, comprising crystallization from a mixed solvent with a second solvent selected from the group consisting of: 2. The method according to claim 1, wherein the first solvent is an aromatic hydrocarbon selected from toluene and xylene, and the second solvent is methanol. 3. The compound of claim 1, wherein R ⁴ is an alkenyl group.
Or the method of 2. 4. The bisphenol monoester is 2- [1
-(2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate, 2- [1- (2-hydroxy-3,5-di-tert-) Pentylphenyl) ethyl] -4,6-di-t-
Pentylphenyl methacrylate, 2-t-butyl-
6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2-t
-Butyl-6- (3-t-butyl-2-hydroxy-5
-Methylbenzyl) -4-methylphenyl methacrylate or 2,4-di-t-butyl-6- [1-
(3,5-di-t-butyl-2-hydroxyphenyl)
4. The method according to claim 3, wherein the compound is ethyl! Phenyl acrylate.