JPH04202220A - Production of aromatic polyester - Google Patents

Abstract

PURPOSE:To obtain an aromatic polyester at a low cost by using a small amount of an organic solvent by precipitating part of the reaction product in the gel to solid form by limiting the amount of an organic solvent used and grinding and mixing the precipitated reaction product. CONSTITUTION:A process for producing an aromatic polyester by the interfacial polymerization of a mixture of a solution of an aromatic dicarboxylic acid dichloride in an organic solvent with a solution of a biphenol in an aqueous alkali solution in the presence of a phase transfer catalyst, wherein the organic solvent is used in such an amount that at least part of the reaction product is precipitated in the gel to solid form in the mid course of the polymerization before the completion of the reaction, and the reaction product is precipitated in a state containing the organic solvent. The reaction is accomplished by grinding and mixing the precipitated reaction product. This process is economical because the use of a large amount of an expensive organic solvent is unnecessary since the reaction product is precipitated in the mid course of the reaction, and improved operability and low equipment cost are possible because the polyarylate can be solidified and granulated simultaneously with its production.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing aromatic polyester.

[Conventional technology]

Aromatic polyesters (hereinafter referred to as "boaryarylates") synthesized from aromatic dicarboxylic acids or their salts and bisphenols have excellent physical properties such as heat resistance, mechanical properties, electrical properties, weather resistance, and transparency. Recently, due to
It is attracting attention as a high-performance engineering plastic.

Various methods are conventionally known as methods for producing polyarylates. For example, ■ known as interfacial polymerization method, ■
A method of mixing and reacting aromatic dicarboxylic acid dichloride dissolved in an organic solvent that is substantially incompatible with water and bisphenols dissolved in an alkaline aqueous solution (Japanese Patent Publication No. 40
(see Japanese Patent Publication No. 2-12974);

In addition, as a method for producing polyarylates other than the interfacial method, there is a solution polymerization method in which aromatic dicarboxylic acid dichlorides and bisphenols are reacted in an organic solvent.
7-5599), ■ Melt polymerization method of heating and melting aromatic dicarboxylic acid ester and bisphenols (Japanese Patent Publication No. 33
-15247, Japanese Patent Publication No. 43-28119), etc. are known.

Among these, the interfacial polymerization methods (■) and (2) are suitable for industrial production and are suitable for industrial production, as they do not require high temperatures and the increase in solution viscosity is low compared to the solution polymerization method (■) and the melt polymerization method (■). It is known that polyester products (boaryarylates) have many advantages, such as excellent transparency.

[Problem to be solved by the invention]

However, in the conventional interfacial polymerization method, (1) it is uneconomical because it uses a large amount of expensive organic solvent, and (2) the polyarylate is dissolved in the organic solvent fi (doped state) at the time of completion of the reaction. (3) The solidification process becomes complicated because the produced polyarylate contains a large amount of organic solvent. (4) When granulating it as a molding material, there are various drawbacks such as the need to further granulate the solidified polyarylate, which increases the number of steps.

As a result of intensive research, the present inventors discovered that if the concentration of organic solvent in the reaction system is lowered, the reaction product will precipitate during the polymerization, but surprisingly, even if precipitation occurs, the It has been found that by pulverizing and mixing the precipitated reaction product in the middle of polymerization, the polymerization reaction continues to proceed even after precipitation.

The present invention was made based on this knowledge, and includes:
The purpose of this is to be economical because it does not require the use of large amounts of organic solvents, and to be suitable for industrial production, where solidification and granulation can be performed at the same time as the production of polyarylates. The present invention provides a method for producing polyarylate.

[Means to solve the problem]

The method for producing polyarylate according to the present invention to achieve the above object is to prepare a mixture of aromatic dicarboxylic acid dichlorides dissolved in an organic solvent and bisphenols dissolved in an alkaline aqueous solution in the presence of a phase transfer catalyst. A method for producing an aromatic polyester in which the organic solvent is reacted with an interfacial polymerization method, wherein a small amount (some of the reaction product is precipitated as a gelled product or a solid) during the polymerization before the reaction is completed. The main point is to precipitate the reaction product in a state containing the organic solvent using the appropriate amount, and to terminate the reaction by pulverizing and mixing the precipitated reaction product.

The aromatic dicarboxylic acid dichlorides mentioned above are not particularly limited in the present invention, and various compounds conventionally used for producing polyarylates can be used. For example, mononuclear aromatic dicarboxylic acid dichloride such as terephthalic acid dichloride and isophthalic acid dichloride; 2.
2- (4,4'-dichlorocarbonyldiphenyl)propane, (4,4'-dichlorocarbonyldiphenyl)
Examples include polynuclear aromatic dicarboxylic acid dichlorides such as ethers, and nuclear substituted products of these mononuclear aromatic dicarboxylic acid dichlorides and polynuclear aromatic dicarboxylic acid dichlorides.

Particularly preferred aromatic dicarboxylic acid dichlorides include:
Examples include terephthalic acid dichloride and isophthalic acid dichloride.

These aromatic dicarboxylic acid dichlorides may be used alone or in combination of two or more as necessary.

The above-mentioned bisphenols are not particularly limited in the present invention, and various types conventionally used for producing polyarylates can be used. for example,
2.2-bis(4-hydroxyphenyl)-propane,
Bis(3,5-dimethyl-4-hydroxy)methane, bis(4-hydroxyphenyl)-sulfone, 4,4゛-
Polynuclear aromatic bisphenols such as dihydroxydiphenyl ether and 4,4゛-dihydroxydiphenyl, mononuclear aromatic bisphenols such as hydroquinone and resorcinol, and nuclear substituted products of these polynuclear aromatic bisphenols and mononuclear aromatic bisphenols. Can be mentioned. Particularly preferred bisphenols include 2,2-bis(4-
(hydroxyphenyl)-propane.

These bisphenols may be used alone or in combination of two or more as necessary.

The phase transfer catalysts include benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetraethylammonium chloride, trioctylmethylammonium chloride, benzyltributylammonium chloride, N-laurylpyridinium chloride, tetrabutylphosphonium bromide, triethyloctadecylphosph Onium bromide is exemplified.

The organic solvent must be substantially insoluble in water and have the ability to dissolve polyarylates, and specifically includes methylene chloride, chloroform, ethylene dichloride, 1.1.2-)lichloroethane, 1.1.2.2-
Examples include chlorinated hydrocarbons such as tetrachloroethane and orthodichlorobenzene.

In addition, organic solvents having polar groups that are inert to the reaction,
For example, nitrobenzene, etc. may be used (Also, taking advantage of the feature of the present invention that the reaction product is precipitated during the reaction, a solvent with low solubility for the polyarylate, such as benzene, It is also possible to use toluene, xylene and mixtures thereof.

The amount of the organic solvent used is particularly important in the present invention. That is, in the present invention, the organic solvent is
It must be used at least to the extent that the aromatic dicarboxylic acid dichloride to be used can be dissolved (lower limit), and an excessive amount must be used to precipitate at least a part of the reaction product during the middle stage of polymerization before the reaction is completed. Must not (upper limit). If it is within this range, it will be set appropriately, and the suitable amount of the organic solvent to be used will naturally vary depending on the solubility of the organic solvent used for the aromatic dicarboxylic acid dichloride and the reaction product. For example, when methylene chloride is used as the organic solvent, it is preferable to use methylene chloride so that the organic solvent concentration defined by the following formula (I) is within the range of 20 to 75%.

Organic solvent concentration (wt%) = organic solvent weight (kg) x 100 organic solvent weight (kg) + reaction product at the end of reaction (b)
--------(I) If the above organic solvent concentration exceeds 80%, the reaction product will not precipitate and will become a highly viscous "glutinous substance", and if it is less than 10%, the reaction will occur at a low degree of polymerization. Since the product precipitates, undesirable phenomena occur, such as a long time required for the reaction to be completed by subsequent pulverization/mixing and a broadening of the molecular weight distribution.

In the present invention, the reaction product is precipitated during the polymerization, but the reaction product at the beginning of the precipitation is often a stick-state sticky substance. , tends to adhere to stirring blades, pipe walls, etc. In order to prevent this, a water-soluble polymer dispersant may be present in the reaction system in advance. As such a water-soluble polymer dispersant, various conventionally known ones can be used, but preferred ones include polyvinyl alcohol, polyvinylpyrrolidone, polyalkylene oxide,
In particular, one or a mixture of two or more of polyethylene oxide, polypropylene oxide, and polyethylene oxide-polypropylene oxide copolymers may be mentioned. The amount of these water-soluble polymer dispersants added varies depending on the type of water-soluble polymer dispersant to be added. For example, in the case of polyvinyl alcohol, it is preferable to add it so that the lower limit is 1,000 ppm or more based on the total weight of the reaction product at the end of the reaction, and the upper limit should be a concentration that does not adversely affect the physical properties of the polyarylate. There is. Usually 5
,000 ppm or less.

In addition, in the case of polyvinylpyrrolidone, 3.000 to 10.000 pl based on the total weight of the reaction product at the end of the reaction.
It is preferable to add at a ratio of :+m.

There is no particular restriction on the timing of adding the water-soluble polymer dispersant to the reaction system as long as it is before all of the reaction products are precipitated, and there is no particular restriction on the method of addition.

Usually, a method is adopted in which an aqueous solution in which a water-soluble polymer dispersant is dissolved is charged in advance into a reactor, or a method in which a bisphenol is dissolved in an alkaline aqueous solution is charged in advance.

The reaction equipment for carrying out the method of the invention must be capable of pulverizing and mixing the precipitated reaction products.

In particular, it is not only possible to prevent the precipitated reaction products from coagulating with each other and to separate the multi-dimensional particles generated by agglomeration, but also to further crush the precipitated reaction products themselves, constantly renewing their surfaces into new surfaces. Reaction equipment with a structure that allows for

Among such reaction equipment, a stirred tank type reaction equipment is preferably a stirred tank that applies impact by high-speed rotating blades and shear by a vortex to the reaction product, and a specific example thereof includes a homogenizer.

Other suitable reaction equipment other than the stirred bed type include:
Examples include reaction equipment equipped with a wet pulverizer. According to this equipment, the reaction product can be precipitated by circulating the reaction solution in the precipitation process within the wet pulverizer. Specific examples include a wet pulverizer, a stirring tank with an agitator, and
An example of this is equipment consisting of piping that connects these two. The above-mentioned wet crusher can be used without any particular restrictions as long as it has a structure that can crush slightly viscous solids in organic solvents, but it can be used without any particular restrictions. is preferred. Commercially available wet grinders that have both of these functions include the "Disinch Grater (product name)" manufactured by Komatsu Zenoah and the "Homo Mitsukline Mill (product name)" manufactured by the Special Machinery and Industrial Equipment Department. It will be done. Note that when a homomick line mill is used, the slurry transfer capacity may be insufficient, so it is preferable to use a pump for slurry transfer together with the homomic line mill. Such a slurry transfer pump must be capable of transferring slurry containing viscous solids, and as a commercially available product, R-Sine Pump (trade name) manufactured by Tokushu Kika Kogyo ■ is suitable. Illustrated as.

【Example〕

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to the following Examples.
It is possible to modify and implement this document as appropriate without changing its gist.

(Example 1) Dissolve 4.4 g of caustic soda in 100 NJ of water, and add 2.2-bis(4-hydroxyphenyl)-
Dissolve 9.68 g of propane and add 0.033 g of a 5G wt% aqueous solution of benzyltributylammonium chloride.
g was added and mixed by stirring.

On the other hand, 1.77 g of terephthalic acid dichloride and 7.06 g of isophthalic acid dichloride were dissolved in 15.3 g of methylene chloride.

Charge the above two liquids into ``Ace Homogenizer AM-7 (trade name)'' manufactured by B Honseiki Seisakusho, and heat at room temperature for 60 minutes.
Stirring was carried out at a stirring speed of 5.00 rpm. After stopping stirring,
When the lid of the Ace homogenizer was opened and the reaction liquid inside was observed, no methylene chloride phase was present, and white granular (amorphous) solids were precipitated in the aqueous phase. This solid material was washed five times in an aqueous hydrochloric acid solution and then in ion-exchanged water, and then placed in a box-type dryer equipped with an exhaust fan and dried at 140° C. for 10 hours to obtain a powdery polyarylate.

The weight average molecular weight Mw of the powdered polyarylate after drying was determined by GPC (gel permeation chromatography) method, and it was found to be 74.0 in terms of polystyrene.
It was 00.

(Example 2) 2.2-bis(4-hydroxyphenyl)-propane 8
．． Dissolve 60g of benzyltributylammonium chloride in 100g of water containing 3.92g of caustic soda.
0.023 g of 0% by weight aqueous solution was added and mixed with stirring.

On the other hand, 1.53 g of terephthalic acid dichloride and 6.12 g of isophthalic acid dichloride were dissolved in 31.5 g of methylene chloride. These two solutions were stirred and mixed under the same conditions using the same equipment as in Example 1 to precipitate white granular (amorphous) solids similar to those in Example 1. This solid was washed and dried in the same manner as in Example 1, and the weight average molecular weight Mw was determined by GPC method, which was 122.0 in terms of polystyrene.
It was 00.

(Example 3) Using the reaction equipment whose flowchart is shown in Fig. 1,
As shown below, aromatic dicarboxylic acid dichlorides and bisphenols were reacted by an interfacial polymerization method in the presence of a phase transfer catalyst to obtain a white granular polyarylate.

The reaction equipment shown in Figure 1 consists of an A monomer preparation tank (1) equipped with a stirrer (2), a B monomer preparation tank (3) equipped with a stirrer (4), and a monomer raw material supplied from these two tanks. A monomer fixed amount supply pump (6) for fixed amount supply
, B monomer constant amount supply pump (9), and a pre-reactor for pre-polymerizing the mixed liquid of both monomers fed from these monomer constant amount supply pumps (6) and (9) to a state where they can be precipitated. It is composed of a static mixer (12), a stirring tank (14), a circulation pump (17), a wet crusher (18), etc. for crushing and mixing the mixed liquid fed from the static mixer (12). It consists of the circulatory system, etc.

In the above reaction equipment, A monomer preparation tank (1
) was charged with 25,233 g of methylene chloride at room temperature, and terephthalic acid dichloride 1,2 was added while stirring under a nitrogen atmosphere.
After adding 30g and 4.921g of isophthalic acid dichloride and completely dissolving them in methylene chloride, brine was poured into the jacket of the A monomer preparation tank (1), and the liquid temperature in the tank was adjusted and maintained at about 5°C. . The monomer thus prepared is hereinafter referred to as "monomer A."

Meanwhile, in the B monomer preparation tank (3), ion-exchanged water at room temperature
After adding 3.230 g of caustic soda and completely dissolving it in ion-exchanged water while stirring under a nitrogen atmosphere, add 53.8 g of sodium dithionite and 2.2-bis(2.2-bis( Add 6.763 g of 4-hydroxyphenyl)-propane and 112.7 g of p-tertiary-butylphenol as a molecular weight moderator of 11, and stir while controlling the temperature so that the liquid temperature in the tank does not fall below 20°C. Dissolved. In addition, the liquid temperature is 20℃
If it is less than 100%, it will take a long time to melt, which is not preferable.

Next, 31.8 g of a 50 weight 96 aqueous solution of benzyltributylammonium chloride and 3.8 g of polyvinyl alcohol (saponification degree: 86.5 to 89.0%) were added to this solution.
After adding 1,032 g of a wt % aqueous solution and stirring and mixing uniformly, the liquid temperature was adjusted and maintained at about 5°C. The monomer thus prepared is hereinafter referred to as "B monomer".

Both monomers A and 8 prepared as described above were pumped into a fixed amount supply pump for A monomer (6) (manufactured by Er Kisou, trade name: "Pulseless Pump"), a fixed amount supply pump for B monomer (9), respectively. (The same type as (6)) is activated, and A
Monomer supply pipe (7), B monomer supply pipe (l
A pre-reactor static mixer (1
2) (Made by Noritake Company, consisting of one Static Mixer T3-21J (trade name) and two Static Mixer T8-21 (with jacket) connected), and a stirrer (15). stirring tank (1
A fixed amount was supplied to 4). The feed rate of monomer A is 273.
3g/min, and the feeding rate of B monomer is 450.0g/min.
It was a minute. The A monomer supply pipe (7) and the B monomer supply pipe (10) are connected as one pipe (31) in front of the inlet of the static mixer (12).
A mixture of both monomers was allowed to flow into the static mixer (12).

In addition, the mixed liquid of both monomers A and B at the beginning of the supply is discharged from the discharge pipe (32) branched from the pipe (31).
The discharge valve (11) provided in the reactor was opened for about 10 minutes to discharge the reactor to the outside of the reaction system.

In addition, before introducing the mixed solution of both monomers A and 8, 12.334 g of ion-exchanged water was charged in advance into the stirring layer (14), and the entire amount of this ion-exchanged water was pumped through the circulation pump (17).
A special equipment department (product name: ``Sine Pump'') was operated to circulate the water. The circulation rate at this time was 801/min.

38 after starting the supply of both monomers to the stirring tank (14)
．． After 3 minutes, the supply of both monomers was stopped. A
, 8 monomers to the stirring tank (14) and even after the supply is stopped, the circulation pump (17) is operated to keep the stirring tank (14)
4) → Circulation vibrator (16) → Circulation pump (17) → Wet crusher (18) (manufactured by Tokushu Kika Kogyo ■, product name "Homo Mikko Line Mill") → Circulation pipe (19) → Circulation pipe (
20)→Circulation in the stirring tank (14) was continued.

During the above circulation, the temperature of the circulating fluid in the stirring tank (14) is set at 5 to 1
It was maintained at 5°C for 1ljlIff.

After 5 minutes had passed after the supply of both monomers A and 8 was stopped, the discharge valve (21) provided on the discharge pipe (22) branched from the circulation pipe (19) was opened, and a small amount of circulating fluid was collected. There was no methylene chloride phase in the collected liquid, and white granular solids (approximately spherical bodies with a diameter of 100 to 300 μm) were precipitated in the aqueous phase. This solid material was washed and dried in the same manner as in Example 1, and the weight average molecular weight M was determined by GPC method, and was found to be 34.000 in terms of polystyrene.

Similarly, 60 minutes and 12 minutes after stopping the supply of A and B monomers.
After 0 minutes had elapsed, samples were taken and the weight average molecular weight M of each was determined, and it was 69 in terms of polystyrene.
,000 and 70,000.

(Example 4) In Example 3, when 38.3 minutes had elapsed after the start of supply of A and B monomers to the stirring tank (14), the discharge valve (21) was opened and 723 .3
It was discharged continuously at a rate of g/min. At this time, the remaining circulating fluid was continued to be circulated. During this discharge, both monomers A and 8 continued to be supplied to the stirring tank (14) at the same supply rate as in Example 3.

The apparent properties of the above discharged liquid were similar to those of the liquid collected in Example 3, but the solid matter was found to be more viscous and tend to adhere more easily than the solid matter obtained in Example 3. After 5 minutes and 60 minutes had elapsed after the start of discharge, the solids in each discharged liquid were washed and dried in the same manner as in Example 1, and the weight average molecular weight Mw was determined by the GPC method, which was 32° in terms of polystyrene. 000 and 66.000.

(Example 5) In Example 3, the mixed solution of both monomers A and 8 was directly poured into the stirring tank (12) without passing through the static mixer (12).
In the same manner as in Example 3, except that monomers A and 8 were supplied to monomer 4), the monomers were collected 60 minutes after the supply of both monomers A and 8 was stopped to obtain a white granular solid. This solid was washed and dried in the same manner as in Example 1, and the weight average molecular weight Mw was determined by GPC method, which was 58,00 in terms of polystyrene.
It was 0.

〔Effect of the invention〕

As explained above in detail, according to the method of the present invention, the reaction product is precipitated during the reaction progress, so it is economical and does not require the use of large amounts of expensive organic solvents. Since the arylate can be solidified and granulated at the same time during production, the present invention has excellent unique effects such as improved operability and reduced equipment costs.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of the reaction equipment used in Examples 3 to 5. (1)...A monomer preparation tank (2)...Agitator (3)...B monomer preparation tank (4)...Agitator (6)...A monomer fixed amount supply pump (7)・・A
Monomer supply pipe (9)...B monomer fixed amount supply pump (10)...
B monomer supply pipe (12)... Static mixer (14)... Stirring tank (15)... Stirrer (17)... Circulation pump (18)... Wet crusher (22)... Discharge pipe (32)... Discharge vibrator Patent applicant Kanebuchi Chemical Industry Co., Ltd. Representative Patent attorney Tomohiro Matsuo Figure 1

Claims (1)

[Claims] 1. An aromatic compound in which a mixture of aromatic dicarboxylic acid dichlorides dissolved in an organic solvent and bisphenols dissolved in an alkaline aqueous solution is reacted by an interfacial polymerization method in the presence of a phase transfer catalyst. A method for producing polyester, the organic solvent being used in an amount such that at least a part of the reaction product is precipitated as a gelled product or a solid during polymerization before the reaction is completed. A method for producing an aromatic polyester, which comprises precipitating it in a state containing a solvent, and terminating the reaction by pulverizing and mixing the precipitated reaction product. 2. The method for producing an aromatic polyester according to claim 1, wherein the reaction product is precipitated in the presence of a water-soluble polymer dispersant. 3. Precipitating the reaction product in a state containing the organic solvent, and applying shear to the reaction product by impact and eddy current when pulverizing and mixing the precipitated reaction product to terminate the reaction. The method for producing aromatic polyester according to claim 1 or 2, wherein a stirring tank equipped with a rotating blade is used. 4. The reaction product is precipitated in a state containing the organic solvent by repeatedly feeding the mixed liquid into a wet pulverizer, and the precipitated reaction product is pulverized and mixed to complete the reaction. 2. The method for producing an aromatic polyester according to 1 or 2. 5. Claims 1 to 5, wherein the mixed liquid is continuously supplied to the reaction system.
4. The method for producing an aromatic polyester according to any one of 4. 6. The method for producing aromatic polyester according to claim 5, wherein the produced aromatic polyester is continuously discharged from the reaction system.