JPS6251258B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an aromatic dihydroxy ester by condensing a divalent phenol compound and an aromatic dicarboxylic acid dichloride in the presence of a basic inorganic compound. For more details,
Aromatic dicarboxylic acid dichloride dissolved in an organic solvent is contacted with a divalent phenol compound dispersed or dissolved in an aqueous phase containing a basic inorganic compound to produce polyester, poly(ester carbonate). The present invention relates to a method for producing a low molecular weight aromatic dihydroxy ester represented by the general formula (1), which is useful as an intermediate raw material for such products. [Here, n is an integer of 1 or more which means the number of repeating structural units derived from the divalent phenol compound and the aromatic dicarboxylic acid dichloride, that is, the degree of polymerization, and X ₁ , X ₂ , X ₃ and x ₄
is hydrogen, Cl, Br or lower alkyl group,
A is the formula A residue derived from a bisphenol type compound represented by
is a bridging group selected from the group represented by CO- and -SO ₂ -); formula a residue derived from a divalent phenol type compound represented by; or A residue derived from a phenolphthalein type compound represented by, where Y ₁ and Y ₂ are hydrogen,
Represents Cl, Br or a lower alkyl group. ] Conventionally, low-temperature or high-temperature solution polycondensation methods and interfacial polycondensation methods are known as methods for condensing divalent phenolic compounds and aromatic dicarboxylic acid dichlorides such as isophthalic acid dichloride and terephthalic acid dichloride. . However, these are all methods for producing high molecular weight polyesters, and these methods are not suitable as methods for producing low molecular weight dihydroxy esters, which is the object of the present invention. The interfacial polycondensation method uses an aqueous phase prepared by dissolving a divalent phenolic compound in an aqueous solution containing an equivalent amount of a basic compound (e.g., sodium hydroxide) to the phenolic hydroxyl group, and a chloride solution. This method is a well-known method in which a solvent such as a chlorinated hydrocarbon such as methylene is brought into contact with an organic phase in which an aromatic dicarboxylic acid dichloride is dissolved with vigorous stirring. However, in this method, even if the divalent phenol compound is reacted with twice the molar amount of the aromatic dicarboxylic acid dichloride, the resulting product has a considerably high molecular weight, and it is difficult to produce a low molecular weight dihydroxy ester. It is inappropriate as such. On the other hand, in low-temperature solution polycondensation, in order to remove hydrogen chloride generated during the reaction, dehydrochlorination agents soluble in the organic solvent used in the reaction, such as tertiary amines such as triethylamine and pyridine, are used. is used. For example, the invention described in JP-A-52-128992 is an example of this, and this invention involves a condensation reaction of bisphenol A and terephthalic acid dichloride in a homogeneous mixed solution of chlorinated hydrocarbon and pyridine. , discloses a method for producing low molecular weight dihydroxy esters. However, the amount of the low molecular weight dihydroxy ester in which n in the general formula (1) is 1 or 2 obtained by this method is almost the same as the amount calculated from the theoretical formula giving Flory's molecular weight distribution, It is stated that the combined amount of both compounds is at most 75% (mol). Furthermore, the purification operations for recovering and reusing tertiary amines such as pyridine used as dehydrochlorination agents in this method are complicated, and this method is not economically viable as a method for producing low molecular weight dihydroxy esters. I can't say it's an advantageous method. A method similar to the high-temperature solution polycondensation method also has many economic disadvantages, such as the treatment of generated hydrogen chloride and the material of the equipment, and cannot be said to be an excellent method for producing low molecular weight dihydroxy esters. In view of the above problems, the present inventors have developed an industrially advantageous method for producing a low molecular weight aromatic dihydroxy ester useful as an intermediate raw material for polymers such as aromatic polyester and aromatic poly(ester carbonate). As a result, we conducted extensive research to find out the solution of water in which a divalent phenol compound was dissolved or dispersed in an aqueous solution containing a basic inorganic compound in an amount equivalent to 0.1 to 1.6 times the mole of the phenol compound. By contacting the phase with an organic solution phase in which an aromatic dicarboxylic acid dichloride is dissolved in an organic solvent such as a chlorinated hydrocarbon, the compound represented by the general formula (1) can be produced in high yield and in the formula n
The present invention was completed based on the discovery that compounds represented by 1 and/or 2 can be obtained with good selectivity. That is, the present invention provides a method for carrying out a condensation reaction by bringing an organic solvent solution phase in which an aromatic dicarboxylic acid dichloride is dissolved into contact with an aqueous phase containing a divalent phenol compound and a basic inorganic compound under stirring. At the same time, aromatic dicarboxylic acid dichloride is reacted with the divalent phenol compound at a molar ratio of 0.1 to 1.0, and the basic inorganic compound is reacted with the divalent phenol compound at a molar ratio of 0.1 to 1 mole.
This is a method for producing a low molecular weight aromatic dihydroxy ester, characterized in that it is used in an amount ranging from 1.6 mol to 1.6 mol. According to the method of the present invention, the aromatic dihydroxy ester having a polymerization degree n of 1 and/or 2 in the formula (1) is contained with high selectivity in the obtained low molecular weight aromatic dihydroxy ester. The condensation reaction can be controlled, which is a major feature of the present invention. Above all, according to the method of the present invention, it is possible to obtain a low molecular weight aromatic dihydroxy ester containing 75 mol% or more of an aromatic dihydroxy ester represented by the above formula (1) and having a degree of polymerization n of 1 and/or 2. Unlike mixtures of various oligomers including high molecular weight oligomers obtained by conventional methods, such low molecular weight aromatic dihydroxy esters are suitable as raw materials for polymers such as polyesters and poly(ester-carbonates) due to their composition. Especially when used as a raw material for poly(ester-carbonate), it gives regularity to the arrangement of the ester bonds and carbonate bonds that form the molecular chain, giving poly(ester-carbonate) various excellent properties. Contribute to granting. Basic inorganic compounds used in carrying out the method of the present invention include lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, trisodium phosphate, and the like. This basic inorganic compound is added to water together with a divalent phenolic compound to form an aqueous phase. In the aqueous phase, this basic inorganic compound reacts with the phenolic hydroxyl group to form a salt, and the salt is Soluble in water. However, as mentioned above, the amount of basic inorganic compounds used is 1 divalent phenol compound.
There are phenolic hydroxyl groups that do not form salts, and are selected in the range of 0.1 to 1.6 moles per mole. Therefore, the aqueous phase usually does not form a homogeneous solution, but forms a dispersion. There is. In this way, 2
By using an aqueous phase in which the divalent phenolic compound is partially neutralized and contains a salt of the divalent phenolic compound dissolved in water and a non-salt-forming divalent phenolic compound dispersed in water. However, it is new that a phenolic hydroxyl group and an acid chloride can easily react, and the above-mentioned low molecular weight aromatic dihydroxy ester can be obtained with good selectivity and high yield without increasing the molecular weight. This is knowledge. This knowledge is based on the well-known method of producing a high-molecular-weight polyarylene ester by subjecting a divalent phenolic compound and an aromatic dicarboxylic acid dichloride to an interfacial polycondensation reaction by converting the phenolic hydroxyl group into a salt, for example, a sodium salt. The results were surprising and unexpected from polymerization technology. As the divalent phenol compound used in the method of the present invention, a bisphenol compound represented by formula (2): Divalent phenol type compound represented by formula (3): and a phenolphthalein type compound represented by formula (2): are used, and an appropriate one is selected from these groups. Here, Y ₁ , Y ₂ and Z mean the same substituent or bonding group as defined in formula (1) above. Representative examples of compounds represented by these general formulas include 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane,
2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)sulfone, bis-(4-hydroxyphenyl)ketone , hydroquinone, resorcinol, and phenolphthalein. Divalent phenolic compounds have a concentration of 0.05 to 2 in the aqueous phase.
It is preferable to use it in a range of mol/, preferably 0.1 to 1.0 mol/. The aromatic dicarboxylic acid dichloride used in the method of the present invention includes terephthalic acid dichloride, 2-chloroterephthalic acid dichloride, 2,5-dichloroterephthalic acid dichloride, isophthalic acid dichloride, 4-chloroisophthalic acid dichloride, 5-chloroisophthalic acid dichloride. Examples include acid dichloride, 2,3,5,6-tetrachloroterephthalic acid dichloride, and the like. These aromatic dicarboxylic acid dichlorides are usually prepared as a homogeneous solution dissolved in an organic solvent, and then brought into contact with an aqueous phase containing a divalent phenol compound. The organic solvent used to dissolve the aromatic dicarboxylic acid dichloride may be an organic solvent that is not completely miscible with water and can separate at least partially from water to form two phases. It is preferably selected from those which dissolve the aromatic dicarboxylic acid dichloride and are inert towards it. Typical examples include dichloromethane, 1,2-dichloroethane, 1,1,2,2-
Tetrachloroethane, chloroform, 1,1,1
-Chlorinated hydrocarbons such as trichloroethane, carbon tetrachloride, monochlorobenzene, dichlorobenzene;
Examples include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; and ether compounds such as diethyl ether, and two or more of these may be used in combination. These organic solvents can also be used in combination with other solvents that have a strong affinity for water, such as ethers, ketones, esters, or nitriles, but the mixed organic solvent system is completely compatible with water. Needless to say, it must be within a range that does not exhibit solubility. The amount of organic solvent to be used may be an amount sufficient to substantially dissolve the aromatic dicarboxylic acid dichloride, and it is usually appropriate to use it in the range of 0.5 to 20 per mole of the aromatic dicarboxylic acid dichloride. be.
Below the lower limit of this range, the production rate of high molecular weight dihydroxy esters (compounds represented by n=3 or more in formula (1) above) tends to increase, and the yield of dihydroxy esters tends to decrease; In addition to a decrease in yield, recovery of the organic solvent is time-consuming, which is economically disadvantageous. The ratio of aromatic dicarboxylic acid dichloride to the divalent phenol compound is expressed as a molar ratio.
The molar ratio is selected from the range of 0.1 to 1.0, and the molar ratio is determined by taking into consideration the amount of basic inorganic compound, reaction temperature, etc. As mentioned above, in the method of the present invention, an aqueous phase containing a divalent phenol compound and a basic inorganic compound and an organic solution phase in which an aromatic dicarboxylic acid dichloride is dissolved are brought into contact with each other under vigorous stirring. The condensation reaction is carried out using a method, but the order of addition and mixing of various raw materials and the form of addition of an aqueous solution are not particularly limited. The volume ratio of the aqueous phase to the organic solution phase is
The ratio may be appropriately selected from the range of 50/1 to 1/40, but it is preferably selected from the range of 1/10 to 10/1 in consideration of economical efficiency of operations such as recovery of solvent and separation of products. One embodiment of the condensation reaction operation in the method of the present invention is to continuously add an organic solvent solution in which an aromatic dicarboxylic acid dichloride is dissolved to an aqueous phase containing a divalent phenolic compound and a basic inorganic compound while vigorously stirring the aqueous phase. This is a method of reacting by dropping the mixture dropwise. At this time, a part of the organic solvent may be added to the aqueous phase in advance. The addition time can be selected as appropriate from a few seconds to several tens of hours, but dropping for too long may partially denature the divalent phenol compound and aromatic dicarboxylic acid dichloride. It cannot be said that it is economically advantageous. On the other hand, it is disadvantageous to carry out the condensation reaction too rapidly because it tends to produce high molecular weight dihydroxy esters. For this reason, 5
Instillation times selected from the range of minutes to 16 hours are preferred. Another embodiment of the condensation reaction operation is to simultaneously and continuously add an organic solvent solution in which an aromatic dicarboxylic acid dichloride is dissolved and an aqueous solution containing a basic inorganic compound to an aqueous phase containing a divalent phenolic compound while stirring. This is a method of dripping. At this time, a portion of the aqueous solution containing the basic inorganic compound may be added in advance to the aqueous phase containing the divalent phenol compound, and the remaining aqueous alkali solution and acid chloride solution may be added dropwise at the same time. In carrying out the method of the present invention, the reaction temperature is 0.
Appropriately selected from the range of ~100°C. Considering the stability of the divalent phenol compound, the aromatic dicarboxylic acid dichloride, the stability of the generated dihydroxy ester, etc., a preferable temperature range is 5 to 75°C. After the aromatic dicarboxylic acid dichloride and the divalent phenol compound have been completely mixed, the reaction time required to continue increasing the reaction rate is 3 hours, although it varies depending on the addition method, reaction temperature, stirring conditions, etc. It is sufficient that The reaction product after the condensation reaction is usually separated into an aqueous phase and an organic solution phase when stirring is stopped and the product is allowed to stand still. At this time, it is desirable to add an acidic aqueous solution containing an acid such as phosphoric acid, hydrochloric acid, or sulfuric acid to the reaction system to adjust the pH of the reaction system to a neutral or acidic side. The produced low molecular weight aromatic dihydroxy ester is generally mostly dissolved in the organic solvent phase, but a portion may be dispersed in the reaction medium as a solid. After the reaction is complete, even if the stirring is stopped, the aqueous phase and organic solution phase may not separate, and the product may be obtained in an emulsified state. In this case, salting out or centrifugation, etc. By separation, an organic solvent solution containing the low molecular weight aromatic dihydroxy ester may be obtained. The organic solvent solution of the low molecular weight aromatic dihydroxy ester thus obtained can be used as an intermediate raw material in the production of polyester or poly(ester-carbonate) by an interfacial method or a solution method. Of course, it is also possible to isolate the low molecular weight aromatic dihydroxy ester in a solid form.
Alternatively, it can be achieved by complete distillation under reduced pressure, or by adding a non-solvent to the organic solvent solution. Furthermore, it is also possible to selectively isolate a compound in which n is 1 or 2 in the formula (1) from the obtained low molecular weight aromatic dihydroxy ester. The compound represented by n = 1 can be isolated by dissolving the obtained dihydroxy ester in methanol and adding water as a non-solvent, and the compound represented by n = 2 can be isolated by This is achieved by dissolving the dihydroxy ester in acetone and adding water as a non-solvent to the solution of the dissolved portion. Analysis of the low molecular weight aromatic dihydroxy ester obtained by the method of the present invention can be performed by high performance liquid chromatography (HLC) using a gel permeation chromatography (GPC) column. Hereinafter, typical embodiments of the method of the present invention for producing low molecular weight aromatic dihydroxy esters will be shown in specific examples. Example 1 15.72g (0.393mol) of sodium hydroxide was added to water.
An alkaline aqueous solution was prepared by dissolving it in 1500ml.
Add 85.68g (0.375g) of bisphenol A to this aqueous solution.
mol) was added and stirred. Approximately half of the bisphenol A was dissolved, and the rest remained in a dispersed state without being dissolved at all even with continued stirring. Methylene chloride was added to the aqueous phase containing bisphenol A and its salts.
ml was added and stirring continued. Dispersed bisphenol A slightly dissolves in methylene chloride, but most remains dispersed in the aqueous phase or methylene chloride phase. A solution of 35.86 g (0.177 mol) of terephthalic acid dichloride dissolved in 750 ml of methylene chloride was added dropwise to this dispersion over 8 hours with stirring, while the reaction temperature was maintained at 20-25°C. The entire amount of dispersed bisphenol A was dissolved in the reaction medium by the time about two-thirds of the acid chloride solution was dropped. After finishing dropping the acid chloride solution and continuing stirring for another 1 hour,
% phosphoric acid aqueous solution was added to bring the pH of the system to 5.5.
When left to stand, it separated into two phases, an aqueous phase and a methylene chloride phase, and the aqueous phase was removed. Methylene chloride was distilled off from the methylene chloride phase at 35°C under reduced pressure, and the resulting solid content was further vacuum-dried at 60°C for 1 hour and at 100°C for 1 hour. The weight of the solid obtained was 108.2g;
This value was in good agreement with the calculated theoretical weight of 108.7 g, which is the sum of all produced esters and unreacted bisphenol A, assuming that 100% of terephthalic acid dichloride was reacted. When the above solid was analyzed by GPC (column packing material, trade name "shodex A802", developing agent chloroform), dihydroxy esters with n ranging from 1 to 5 and unreacted bisphenol A were confirmed as shown in the following formula (5). . Table 1 shows the content of each hydroxy ester in all esters determined by the internal standard method in mol%. H-A(-B-A)― _o H……(5) However

[Table] Example 2 Bisphenol A was prepared in the same manner as in Example 1.
85.62g, sodium hydroxide 15.70g and water
The aqueous phase was prepared from 1500ml. Methylene chloride in the aqueous phase
Add 750ml isophthalic acid dichloride
A solution of 35.86 g dissolved in 750 ml of methylene chloride was added dropwise at 20 to 25° C. over 4 hours with stirring. After continuing stirring for another 2 hours, the pH was adjusted in the same manner as in Example 1, and when stirring was stopped, the mixture was separated into an aqueous phase and a methylene chloride phase. Methylene chloride was distilled off from the organic phase to obtain a white solid consisting of a low molecular weight aromatic dihydroxy ester and unreacted bisphenol A. Of this, unreacted bisphenol A was 10.32g, and low molecular weight aromatic dihydroxy ester was
It weighed 98.2g. This white solid is mixed with about 2 methanol
and separated into insoluble matter and liquid by filtration. When 400 ml of water was added to the liquid, a white solid precipitated, and this white solid was collected again by filtration.
Dry. The IR spectrum of the obtained white solid had characteristic absorption as di(bisphenol A) isophthalate, and both the elemental analysis values and the amount of phenolic hydroxyl groups agreed with the theoretical values. In addition, the purity of the white solid di(bisphenol A) isophthalate determined by GPC (internal standard method) is 98.5%, and the content of di(bisphenol A) isophthalate in the total ester is 87.0 mol%. It was hot. Example 3 Sodium hydroxide 23.540g (0.589mol) and water
An alkaline aqueous solution was prepared from 1500 ml, and 85.615 g (0.375 mol) of bisphenol A was added to create an aqueous phase. Add 500ml of methylene chloride to the aqueous phase,
A solution of 35.861 g (0.177 mol) of terephthalic acid dichloride dissolved in 1.0 methylene chloride was added dropwise with stirring at 20° C. over 8 hours. Bisphenol A, which had been dispersed without being dissolved in either the alkaline aqueous solution or methylene chloride, was almost completely dissolved in the reaction medium when about 1/4 of the methylene chloride solution of terephthalic acid dichloride had been dropped. After the addition was completed, stirring was continued for another hour, and then 4%
After adding phosphoric acid aqueous solution and adjusting the pH to 5.5,
The organic solvent phase was separated and collected. water in the organic solvent phase
After adding 500 ml and stirring, the organic solvent phase was separated and collected again, and the methylene chloride was distilled off under reduced pressure at 35°C. Further, the residual solvent was removed by vacuum drying at 100°C to obtain a low molecular weight aromatic dihydroxy ester. As a result of analyzing the obtained white solid by GPC, it was found that 80 mol% of dihydroxy esters in which n is 1 and 2 in the above formula (5) were contained in all esters.
It was included. A portion of 5 g of the white solid was dissolved in 50 ml of acetone, insoluble matter was removed by filtration, and 13 ml of water was added to the solution to precipitate a white powder. white powder
The IR spectrum had a characteristic absorption band of dihydroxy ester, and the elemental analysis value and hydroxyl group concentration were in good agreement with the theoretical value of dihydroxy ester where n is 2. Example 4 An alkaline aqueous solution consisting of 15.71 g (0.393 mol) of sodium hydroxide and 1.5 mol of water was prepared, and to this was added 171.264 g (0.750 mol) of bisphenol A.
mol) was added to create an aqueous phase in which bisphenol A was dispersed. A solution of 35.861 g (0.177 mol) of terephthalic acid dichloride dissolved in 1.0 methylene chloride was added dropwise to this aqueous phase over 6 hours with stirring. After continuing stirring for 1 hour,
Throughout the entire process, unreacted bisphenol A remaining in a dispersed state was recovered. Thereafter, only the methylene chloride phase was separated and collected, washed with a 2% aqueous phosphoric acid solution and separated, and the methylene chloride was distilled off in the same manner as in Example 3 to obtain 121.5 g of solid matter. G.P.C.
As a result of analysis, the solid content contained 24.25 g of bisphenol A, and the remainder was low molecular weight aromatic dihydroxy ester. Example 5 Sodium hydroxide 15.70g (0.393mol) and water
An alkaline aqueous solution was prepared from 500 ml. Bisphenol A 85.67g (0.375mol), water 1.0
, 100 ml of the above alkaline aqueous solution was added to a dispersion of 750 ml of methylene chloride and stirred. A solution prepared by dissolving 35.86 g (0.177 mol) of terephthalic acid dichloride in 750 ml of methylene chloride and the remaining 400 ml of the alkaline aqueous solution were simultaneously started to be added dropwise at 25° C. with stirring. The addition was carried out over a period of 8 hours.
After the dropwise addition was completed, the reaction was further continued at 25°C for 2 hours. Analysis of the reaction product by HLC revealed that di(bisphenol A) terephthalate (dihydroxy ester with n=1 in formula (5)) was 84 mol% and dihydroxy ester with n=2 was 14 mol%. each included. Examples 6 to 15 According to the method of Example 1, divalent phenol compounds and aromatic dicarboxylic acid dichlorides were prepared.
The reaction was carried out according to the recipe shown in 2. Display the results.
Shown in 2. The product dihydroxy ester represented by the above general formula (1) must contain 75 mol% or more of a compound where n is 1 or 2.

【table】

[Table] You can see that. Reference example 1 Sodium hydroxide 31.58g (0.790mol) and water
An alkaline aqueous solution was prepared from 1500 ml, and 85.71 g (0.375 mol) of bisphenol A was added thereto and stirred. The resulting aqueous phase became a homogeneous and transparent aqueous solution. After adding 750 ml of methylene chloride to this aqueous phase, a methylene chloride solution of terephthalic acid dichloride in the same amount and proportion as in Example 1 was added dropwise under the same conditions as in Example 1. By the time 1/2 of the total amount of the methylene chloride solution of terephthalic acid dichloride was added dropwise, solid precipitation was observed, and the entire solution was in an emulsified state. After the dropwise addition was completed, stirring was continued for 1 hour, and then a 4% aqueous phosphoric acid solution was added to adjust the pH to 5.5. After removing a portion of the aqueous phase that had separated, methylene chloride was distilled off. The solid was then filtered, washed with water, and dried. The logarithmic viscosity of this solid (measured using a mixed solvent of phenol:tetrachloroethane=6:4 at 25°C and 1.0g/100ml) is 0.253, and the content of di(bisphenol A) terephthalate is 10%. It was below.

Claims (1)

[Claims] 1. When carrying out a condensation reaction by bringing an organic solvent solution phase in which an aromatic dicarboxylic acid dichloride is dissolved into contact with an aqueous phase containing a divalent phenol compound and a basic inorganic compound under stirring, the divalent The aromatic dicarboxylic acid dichloride is reacted with the phenolic compound in a molar ratio of 0.1 to 1.0, and the basic inorganic compound is reacted in an amount of 0.1 to 1.6 mol with respect to 1 mol of the divalent phenol compound. A low molecular weight product containing as a main component an aromatic dihydroxy ester having the number of repeating structural units (degree of polymerization) of 1 and/or 2 derived from a divalent phenol compound and an aromatic dicarboxylic acid dichloride. A method for producing an aromatic dihydroxy ester.