JP4895632B2 - Method for producing polyarylate - Google Patents

Description

  The present invention relates to a method for producing polyarylate, and more particularly to a method for producing polyarylate having an inherent viscosity of 0.84 to 1.80 dl / g.

  Polyarylate is excellent in mechanical properties, electrical properties and the like, and is widely used as an engineering plastic in various fields such as the electrical / electronic equipment field, the automobile field, and the OA equipment field. In particular, a high molecular weight polyarylate having an inherent viscosity of 0.84 to 1.80 dl / g has high strength when used as a coating material, and its industrial utility value is extremely high.

  Polyarylate is produced by using a known polyester polymerization method using dihydric phenol and aromatic dicarboxylic acid or a derivative thereof as raw materials. Examples of the polymerization method include interfacial polymerization, solution polymerization, and melt polymerization, and interfacial polymerization is preferable.

Interfacial polymerization is performed by mixing an aqueous phase in which a dihydric phenol is dissolved in an alkaline aqueous solution and an organic phase in which a divalent carboxylic acid halide is dissolved in an organic solvent not dissolved in water in the presence of a catalyst. (W. M. EARECKSON, J. Poly. Sci. XL399 (1959), Japanese Patent Publication No. 40-1959). Interfacial polymerization is faster in reaction than solution polymerization, and acid halide hydrolysis is minimized, and as a result, a high molecular weight polyarylate can be obtained.
In particular, when producing a high molecular weight polyarylate having an inherent viscosity of 0.84 dl / g or more, it is necessary to minimize hydrolysis of the acid halide. As the method, for example, as shown in Patent Document 1, 0.84 to 0.91 dl / g (1,1,2,2,) using a polymerization catalyst (tri-n-butylbenzylammonium chloride) having a high polymerization rate is used. There is a method for producing high molecular weight polyarylate having an inherent viscosity of 2-tetrachloroethane (measured at 25 ° C.).

However, the above method alone is insufficient to stably obtain a high molecular weight polyarylate having an inherent viscosity of 0.84 dl / g or more in actual industrialization. In other words, in industrialization, it is necessary to scale up from glass tube polymerization (several g to several kg) in a laboratory to a reaction kettle (several tens to several hundred kg) in a manufacturing plant. Unlike the glass tube in the laboratory, the shape of the stirring blade and the number of rotations must be optimally selected because of the difference in heat transfer state due to the increase in capacity. For this reason, it is difficult to produce a resin having the same characteristics as in the laboratory because the same stirring state cannot be obtained. Also in the above method, it was difficult to stably obtain a polyarylate having an inherent rate of 0.84 dl / g or more due to a difference in stirring state.
Japanese Patent Laid-Open No. 5-43670

The present invention is technically intended to solve the above problems and provide a method for producing polyarylate capable of industrially producing polyarylate having an inherent viscosity of 0.84 to 1.80 dl / g in an industrially stable manner. This is a major issue.

As a result of intensive studies to solve the above problems, the present inventors have found that the problem can be solved by setting the stirring power within a specific range in the presence of a specific polymerization catalyst, and have reached the present invention. did.
That is, the present invention provides a inherent viscosity 0.84~1.80dl / g and a polyarylate manufacturing method comprising the dihydric phenol component and an aromatic dicarboxylic acid component, in interfacial polymerization reaction step, maxblend type Interfacial polymerization is performed using a blade in the presence of a polymerization catalyst represented by the following formula (1) while adjusting the rotational speed of the stirrer so that the stirring power is 0.4 to 1.2 kW / m ^3. The method for producing polyarylate is as follows.

(In the formula, Y represents a butyl group or a benzyl group, and X represents a halogen atom of Cl or Br, OH, or HSO _4. )

According to the present invention, it is possible to stably produce a polyarylate having a high inherent viscosity of 0.84 to 1.80 dl / g. Since the polyarylate obtained by the present invention has a remarkably high strength, when it is used as a coating material, it can be widely used in the electrical / electronic field and the like, and its industrial utility value is extremely high.

  Hereinafter, the present invention will be described in detail.

  The polyarylate referred to in the present invention is a polyester composed of a dihydric phenol residue and an aromatic divalent carboxylic acid residue.

  In the present invention, examples of the dihydric phenol component include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), 2,2 -Bis (3-methyl-4-hydroxyphenyl) propane (bisphenol C), 1,1-bis (4-hydroxyphenyl) -1-phenylethane (bisphenol AP) and the like can be used.

  Examples of the aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 3-tert-butylisophthalic acid, diphenic acid, and 4,4′-dicarboxylic acid. These divalent dicarboxylic acids can be used alone or in combination of two or more. Aromatic dicarboxylic acids that can be particularly preferably used are terephthalic acid and isophthalic acid, and particularly preferred is an equivalent mixture of both.

  In the present invention, basically, an aqueous phase in which a dihydric phenol is dissolved in an alkaline aqueous solution and an organic phase in which a divalent carboxylic acid halide is dissolved in an organic solvent not dissolved in water are mixed in the presence of a catalyst. Thus, interfacial polymerization is performed to produce polyarylate. Examples of the alkali used in the aqueous phase include sodium hydroxide and potassium hydroxide.

  As the solvent used in the organic phase, a solvent that is incompatible with water and dissolves the polyarylate produced is used. Specifically, methylene chloride, 1,2-dichloroethane, chloroform, Chlorinated solvents such as carbon chloride, chlorobenzene, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, toluene, benzene, xylene, etc. Aromatic hydrocarbons, tetrahydrofuran and the like.

  The specific polymerization catalyst used in the present invention is a quaternary ammonium salt having a chemical structure represented by the above formula (1), specifically, tri-n-butylbenzylammonium chloride, tri-n-butyl. Benzylammonium bromide, tri-n-butylbenzylammonium hydride, tri-n-butylbenzylammonium hydrogen sulfate, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium hydroxide, tetra-n-butyl Examples include ammonium hydrogen sulfate.

  In order to adjust the molecular weight of the polyarylate, an end-stopper can be used during the polymerization. Examples of the terminal terminator include monovalent phenols such as phenol, cresol, and p-tert-butylphenol, and monovalent acid chlorides such as benzoic acid chloride, methanesulfonyl chloride, and phenyl chloroformate.

  In the interfacial polymerization, a high molecular weight polyarylate is obtained by mixing an organic phase solution with the aforementioned aqueous phase solution and performing an interfacial polycondensation reaction with stirring at a temperature of usually 25 ° C. or lower for 1 to 5 hours. be able to.

  In the present invention, inherent viscosity is used as an index indicating the molecular weight of polyarylate. The polyarylate targeted by the present invention is required to have an inherent viscosity of 0.84 to 1.80 dl / g measured under the conditions described below. The preferred inherent viscosity is 0.84 to 1.60 dl / g, optimally 0.90 to 1.40 dl / g. When the inherent viscosity is less than 0.84 dl / g, the mechanical strength as a coating material is lowered, while when it exceeds 1.80 dl / g, the workability when forming a coating is lowered.

As the polyarylate reactor used in the present invention, a tank reactor equipped with a stirrer is used. For stirring during the reaction, it is necessary to control the stirring power within the range of 0.4 to 1.2 kW / m ³ . The preferable range of the stirring power is 0.5 to 1.0 kW / m ³ , and optimally 0.6 to 0.8 kW / m ³ . When the stirring power is less than 0.4 kW / m ³ , sufficient mixing of the aqueous phase and the organic phase cannot be obtained, the contact area between the aqueous phase and the organic phase is reduced, and the reaction rate is decreased. As the decomposition proceeds, the high molecular weight polyarylate of the present invention cannot be obtained.

Moreover, even when the stirring power exceeds 1.2 kW / m ³ , a high molecular weight polyarylate cannot be obtained. The reason why such a result appears is not fully understood, but can be inferred as follows.

  That is, as described above, in order to obtain a high molecular weight polyarylate by interfacial polymerization, it is important to increase the polymerization rate. In this case, it is particularly necessary to increase the initial polymerization rate. More specifically, in the interfacial polymerization of polyarylate, the dihydric phenol ion (hereinafter referred to as phenoxide ion) dissolved on the aqueous phase side is moderately hydrophobic with the ammonium ion and the hydrophobic catalyst. By forming a salt, the lipophilicity is increased and the transfer rate to the organic phase is sufficiently increased. As a result, the esterification reaction with an acid halide is promoted to increase the degree of polymerization of polyarylate. In this case, it is considered that the movement speed of the hydroxide ions to the organic phase is relatively greatly reduced, and hydrolysis of the acid halide by the hydroxide ions is remarkably suppressed. In other words, in interfacial polymerization of polyarylate, high-molecular-weight polyarylate is obtained by promoting esterification reaction with a polymerization catalyst among esterification reaction with phenoxide ions and hydrolysis reaction with hydroxide ions, which are competitive reactions. It is thought that. Therefore, in order to obtain a polyarylate having a high inherent viscosity as in the present invention, a polymerization catalyst having a highly hydrophobic ammonium ion is effective for increasing the reaction rate, particularly the reaction rate at the initial stage of polymerization.

However, when the stirring power exceeds a certain value, the interfacial area between the aqueous phase and the organic phase is forcibly reduced, and in the extreme case, the emulsion is completely emulsified. In this case, the migration rate of the hydroxide ions from the aqueous phase to the organic phase was relatively slow due to the polymerization catalyst, but the interface area between the aqueous phase and the organic phase decreased. It is presumed that the ion transfer rate increases and the acid halide hydrolysis rate increases, so that the esterification reaction does not proceed and a high molecular weight polyarylate cannot be obtained. Therefore, it is necessary to carry out the polymerization reaction with a stirring power of 1.2 kW / m ³ or less.

Further, as the stirring blade for stirring with the stirring power described above, it is preferable to use a Max blend type blade from the viewpoint of homogenizing the time until mixing and heat transfer in the can. Has Max Blend Tsubasa (registered trademark of Sumitomo Heavy Industries, Ltd.).

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited only to an Example. In addition, the measuring method of the physical property in an Example is as follows.
(1) Inherent viscosity (η _inh )
1,1,2,2-Tetrachloroethane was used as a measurement solvent, and measurement was performed under the conditions of a concentration of 1 g / dl and a temperature of 25 ° C.
Example 1
The tank-type reaction vessel was equipped with a Max Blend blade as schematically shown in FIG. 1 as a stirrer. Among them, 39 kg (154 mol) of 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol C) as a dihydric phenol, p-tert-butylphenol (end stopper) Hereinafter, abbreviated as PTBP.) 392 g (2.6 mol), 16 kg (403 mol) of sodium hydroxide, and tri-n-butylbenzylammonium chloride (hereinafter abbreviated as TBBAC) as a polymerization catalyst were added to all divalent phenols. 0.67 mol% (322 g) was dissolved in 1042 L of water (aqueous phase). Separately, 32 kg (155 mol) of a terephthalic acid chloride / isophthalic acid chloride = 1/1 mixture (hereinafter abbreviated as MPC) was dissolved in 613 L of methylene chloride (organic phase).

The organic phase was added to the aqueous phase with the stirring speed adjusted to a stirring power of 0.65 kw / m ³ under strong stirring, and an interfacial polycondensation reaction was performed at 15 ° C. for 2 hours. After stopping the polymerization, the aqueous phase and the organic phase were decanted and separated. After removing the aqueous phase (alkaline water), acetic acid was added until the pH was less than 7 while adding an equal amount of ion-exchanged water and stirring. Furthermore, after stirring for 20 minutes, the operation of decanting for 20 minutes to remove the aqueous phase and replacing it with new ion-exchanged water was repeated three times. The polymer solution, which is the organic phase after washing, was poured into 50 ° C. warm water contained in a container equipped with a homomixer to evaporate methylene chloride to obtain a powdery polymer. This powdery polymer was dried in a vacuum dryer at 120 ° C. for 24 hours under reduced pressure to obtain a polyarylate resin.
(Examples 2-5, Comparative Examples 1-3)
A polyarylate resin was obtained in the same manner as in Example 1 except that the type of dihydric phenol and the stirring power were changed as shown in Table 1 in Example 1.

Table 1 also shows the inherent viscosities of the polyarylate resins obtained in Examples 1 to 5 and Comparative Examples 1 to 4.

As apparent from Table 1, in Examples 1 to 5, polyarylate having sufficient inherent viscosity could be produced.

  On the other hand, in Comparative Examples 1 and 3, since the stirring power was out of the range specified in the present invention, the inherent viscosity of the obtained polyarylate was low. In Comparative Example 2, since the polymerization catalyst was not a compound satisfying the formula (1), the obtained polyarylate had a low inherent viscosity.

It is the schematic which shows the Max blend type | mold blade | wing which is one embodiment of the stirring blade used by this invention.

Claims (1)

A method for producing a polyarylate having an inherent viscosity of 0.84 to 1.80 dl / g comprising a dihydric phenol component and an aromatic dicarboxylic acid component, and using a max blend type blade in an interfacial polymerization reaction step, Production of polyarylate characterized by interfacial polymerization in the presence of the polymerization catalyst represented by formula (1) while adjusting the rotational speed of the stirrer so that the stirring power is 0.4 to 1.2 kW / m ^3. Method.
(In the formula, Y represents a butyl group or a benzyl group, and X represents a halogen atom of Cl or Br, OH, or HSO _4. )