KR940010011B1 - Process for preparation of polyarylate - Google Patents

Abstract

This method is for preparation of polyarylate having high purity by direct reaction of reactants with melt polymerization without catalyst and crystallization solvent. A dihydric phenol or its derivatives and dicarboxyl acid or its derivatives directly reacts by three step having different temp. and time. The process in consist of: 1st step, reacting at 120-140 deg.C for 10-30 min and injecting N2 gas of 800-1000 ml/min; 2nd step, under same temp., leave alone without stirring for 2 hr; 3rd step, reacting at 260-280 deg.C for 40-70 min and injecting N2 gas of 800 ml/min over 250 deg.C with 120-180 rpm.

Description

Method for preparing polyarylate

1 is an H-NMR data comparison graph of a polyarylate (a) according to a known method and a polyarylate (b) prepared according to the present invention.

The present invention relates to a method for producing polyarylate by melt polymerization, and more particularly, to directly obtain a polyarylate with high purity by directly reacting a reactant by melt polymerization without using a catalyst or a crystallization solvent. It relates to a new manufacturing method.

Generally, polyarylaters, which are classified as special engineering plastics, can be divided into interfacial polymerization, solution polymerization, and melt polymerization.

The polyarylate prepared by interfacial polymerization among them is commercialized under the trade name of U-100 in Unitika, etc., but the product according to the polymerization method has a problem in that the yield of polymer per reactor is too low. Thus, methods for producing polymers with higher yields have been proposed.

On the other hand, in general, the melt polymerization method has an advantage of directly polymerizing a polymer obtained by melt polymerization of an ester obtained from an aromatic diol and an aromatic dicarboxylic acid, but has problems in high temperature, delay of reaction time, coloring of reaction product, and the like. It is happening.

In addition, U.S. Patent No. 4,485,230 and Japanese Patent Publication No. 60-53527 disclose a polyarylate production technique by melt polymerization method, but in this case, the melt viscosity increases rapidly as the polymerization degree of the polymer increases. It is not possible to produce polyarylates having a molecular weight of polymerization degree.

Therefore, in order to solve this disadvantage, U.S. Patent Nos. 3,684,766, 3,780,148 and 4,612,360 first proposed a method of preparing a polymer by solid phase polymerization by pulverizing the oligomer and then pulverizing the oligomer. .

According to this method, it is necessary to crystallize the polymer by bringing the oligomer into contact with the crystallizing agent, thereby creating a new problem that the manufacturing process is very complicated and difficult.

In addition, according to Japanese Patent Application Laid-Open No. 57-2331, in order to omit the crystallization process pointed out above, a manufacturing method has been developed in which diphenol ether or the like coexists in the preparation of the oligomer which is the first step. In the case of this method, it is possible to eliminate the crystallization process, but the disadvantage of deteriorating the good physical properties of the polymer has been pointed out as a problem.

In addition, Japanese Patent Application Nos. 59-177650 and 60-51940 have also proposed methods for producing a high degree of polymerization of polyarylate, but in this case, in order to manufacture a product having a higher degree of polymerization, the oligomer is usually about 10 hours. Since it needs to be polycondensed above, it becomes a big disadvantage in process.

In addition, according to Japanese Patent Application No. 59-257195, a reduced pressure kneading polymerization method has been proposed. However, even when this method is used, since the melt viscosity is considerably high, the rate of transport of the bulk material is extremely poor, so that polyarylate of high polymerization degree is obtained. There is a problem that manufacturing itself is very difficult.

As such, it is very difficult to melt polymerize an ester compound obtained from an aromatic diol and an aromatic dicarboxylic acid to obtain a polyarylate having a molecular weight that is high enough to be commercially available.

Therefore, the present inventors have not been able to obtain a method of preparing a polymer having a satisfactory molecular weight in spite of various melting methods. To develop a new method for preparing a polyarylate polymer having a complete the present invention.

Accordingly, the present invention provides a high purity and high yield of high molecular weight polyarylate in a simple and convenient way by directly reacting the reactants without using a catalyst or crystallization solvent in the production of polyarylate by melt polymerization method. It is an object of the present invention to provide an improved method for manufacturing.

Hereinafter, the present invention will be described in detail.

The present invention is characterized in producing polyarylate by directly reacting dihydric phenol or its derivative with aromatic dicarboxylic acid or its derivative as a reactant in preparing polyarylate by melt polymerization method.

Referring to the present invention in more detail as follows.

The present invention is a method for synthesizing polyarylate from dihydric phenol and its derivatives and aromatic dicarboxylic acid and its derivatives by melt polymerization as a reactant. In particular, all existing methods use catalysts or crystallization solvents. In contrast, the present invention is a method of directly obtaining the desired polymer by directly reacting the reactants.

Further, in the present invention, in order to improve the physical properties of the polyarylate polymer, it is more preferable to use the aromatic dicarboxylic acid to be used as a mixture of isophthalic acid and terephthalic acid.

Dihydricphenols that may be used in the present invention include, for example, resorcinol, hydroquinone, diphenol, dihydroxynaphthalene, bis (4-hydroxyphenyl) methane (bisphenol F), 1,1-bis (4hydroxy) Phenyl) ethane (bisphenol E), 1,2-bis (4-hydroxyphenyl) ethane (bisphenol E), bis (4-hydroxyphenyl) sulfide, 2,2-bis (4-hydroxyphenyl) propane ( Bisphenol A), bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) sulfone, etc. are mentioned. Among these, bisphenols F, E and A are preferred. In addition, derivatives that may be used simultaneously may be those substituted with C ₁ -C ₂ alkyl and halogen.

In addition, examples of the aromatic dicarboxylic acid used in the present invention include terephthalic acid, isophthalic acid, dibenzoic acid, naphthalenedicarboxylic acid, bis (4-carboxyphenyl) methane and 1,2-bis (4-carboxyphenyl). Ethane, 2,2-bis (4-carboxyphenyl) propane, bis (4-carboxyphenyl) oxide, bis (4-carboxyphenyl) sulfide, and bis (4-carboxyphenyl) sulfone, and the like. Terephthalic acid or isophthalic acid may be used as the furnace, and most preferably, a mixture of terephthalic acid and isophthalic acid in an appropriate ratio is preferable. At this time, terephthalic acid and isophthalic acid is preferably used in a mixture of 70-50 mol% vs. 30-50 mol%.

In addition, as the aromatic dicarboxylic acid derivative that can be used at the same time, an alkyl or a halogen substituted compound may be used, and among these, a halogen substituent is more preferable.

On the other hand, looking at the reaction process of the present invention in detail, the reaction proceeds in three steps while varying the reaction temperature and time, first reacting the mixture at 120 ~ 140 ℃ the first reaction.

At this point the reactants begin the reaction and produce an acid such as, for example, HCl. The secondary reaction then reacts near the glass transition temperature, where the darkened reactants become light yellow as the degree of polymerization increases.

After such a reaction, the reacted polymer material has a high melt viscosity at which no further sterling is possible. At this time, the temperature was continuously raised in order to lower the melt viscosity in the conventional methods, but in the present invention, the reaction mixture is stopped at this temperature and allowed to stand for 2 hours while slowly injecting nitrogen gas.

Then, in the third reaction, the reactants are raised to 250 ° C. to 300 ° C., and the reactants are dissolved and stirred for about 1 to 2 hours.

During this process, the reactants become low in viscosity to the point of agitation.

Next, the desired polyarylate is obtained by removing the resulting gaseous acid component and cooling. As a result of measuring the intrinsic viscosity to determine the molecular weight of the prepared polymer, it was confirmed that a polyarylate having a molecular weight of about 0.6 to 0.7 was obtained.

This is the same size as the molecular weight of the U-100 series products manufactured and commercialized by Unitika, and exhibits sufficient physical properties as engineering plastics.

The process of the present invention will be described in more detail, where the reaction is carried out in a reactor having 250 ml three necks with an aromatic dicarboxylic acid or a substituent thereof, such as an isophthalic halide and terephthalic halide 50/50 mixture of 0.1-. After adding about 0.2mol, it melt | dissolves fully to about 90 degreeC, and fully mixes two reactants using a stainless stirrer.

Then, when the reactants are mixed well, slowly add 0.1-0.2 mole of dihydricphenol while slowly heating. Then, the two reactants are reacted at a temperature between 120 ° C. and 140 ° C., and the HCl gas is generated little by little while starting the reaction near 100 ° C.

At this time, the nitrogen gas is not injected for about 1 to 2 minutes, and when the temperature is 120 ° C. or higher, nitrogen gas is started and the rotational speed (rpm) is also increased to 600 to 1000. The reactant then continues to rise, rising straight up to around 140 ° C.

Important factors at this stage are the reaction temperature, the degree of mixing of the reactants, the rotational speed, the rate of nitrogen gas injection and the reaction time. In particular, when the aromatic dicarboxylic acid compound and the dihydric phenol compound are placed and mixed at the same time in order to increase the degree of mixing of the reactants, the melting temperature of the mixture is severely different and not sufficiently mixed.

Therefore, a compound having a low melting point (usually a dicarboxylic acid compound) is first melted, and then sufficiently mixed with two dicarboxylic acids, and then a dihydric phenol compound is added thereto to almost complete mixing.

In this reaction, the reaction temperature is suitably about 120 ° C. to 140 ° C., and when it is 150 ° C. or more, it is very difficult to establish reaction conditions due to too much evaporation of the dicarboxylic acid compounds. Therefore, the temperature is very suitable in the range of about 120 ~ 140 ℃.

On the other hand, the rotational rpm during the reaction is good between 600 ~ 1000, using a motor capable of starvation shifting should be possible depending on the size of the viscosity of the reactants. According to the present invention, the viscosity of the reactants at this stage is very low, and the rpm was about 800.

This is necessary in order to reduce the molecular weight distribution of the final product by equalizing the probability of reacting with each other as the reactants are polymerized on the reaction mechanism. It is also necessary to maintain a high rpm for the smooth removal of HCl gas.

Next, the injection rate of nitrogen gas is about 800 ~ 1000ml / min. If it is higher than that, the reactants are also blown away, which affects the final physical properties very badly. When nitrogen is injected at this rate, HCl gas generated as the reaction proceeds, It can be smoothly blown out of the reactor, and a very small flow will make it difficult to remove the HCl gas.

However, if nitrogen gas is preheated to 180 ℃ or higher and injected at 1000ml / min or more in two stages, HCl gas can be removed smoothly to prevent decomposition of product by HCl during the reaction, thereby improving the physical properties of the product. .

The temperature of the nitrogen gas thus injected should not be significantly different from the temperature of the reactants, but it was found that in one-stage reaction, even if the nitrogen gas under normal temperature is injected as it is, it does not matter much.

The next most important factor is the reaction time. As a result of analyzing the experimental results, the polymer reacted for 30 minutes or more at the secondary reaction temperature was dissolved in 0.5g of polymer (molecular viscosity-phenol and tetrachloroethane 60/40 mixture). ) Does not exceed 0.5 and the color is severely colored, resulting in a very poor polymer.

In addition, when the reaction time is not long enough, a polymer having a very wide molecular weight distribution is obtained. Therefore, as a result of several experiments, it was found that 10 minutes to 30 minutes were appropriate, and 15 minutes to 25 minutes were particularly appropriate.

After the reaction proceeds first, the reaction is carried out in the vicinity of the glass transition temperature 1 ~ 10 ℃ higher than the glass transition temperature (about 192 ℃) of polyarylate to proceed with the secondary reaction. At this time, the rpm should be about 500 ~ 600 and keep stirring until no more stirring is possible.

In this way, as the reaction proceeds gradually, the reactants which turned red in the first reaction turn pale yellow, and the viscosity becomes very large. At this time, if the stirring speed is maintained at about 300rpm, the Weisenberg effect, that is, the viscoelastic nature of the polymer prevents the rise of the polymer due to the phenomenon that the polymer is continuously going up along the motor shaft.

Thus, when stirring is no longer possible, it is allowed to stand at this temperature for 1 to 2 hours. Here, of course, the stirring motor is stopped but nitrogen gas is heated to 180 ° C and continuously injected. Otherwise, this is undesirable because the temperature of the reactants is not uniform and affects the properties of the final product.

After standing for 1 to 2 hours in this manner, the reactant is heated rapidly and raised to 260 ℃ ~ 280 ℃ necessary for the third reaction and stirred. At this time, the produced polymer is very high in viscosity, and keep mixing at about 120-180 rpm around 270 ° C.

After 40 ~ 70 minutes of reaction at this temperature, almost 100% of the reaction is completed, and then vacuum is applied. This is to completely remove the HCl gas remaining in the reactants and continue to react for 5 to 10 minutes under a vacuum of 5 to 10 Torr. Then stop everything and cool slowly to end the reaction.

In this case, in order to neutralize the generated HCl gas, the NaCl aqueous solution is made and the HCl gas is neutralized by contacting the HCl gas with the NaOH aqueous solution through the glass dispersion network.

1 shows H-NMR data of polyarylate by melt polymerization and polyarylate (trade name; U-100) prepared by interfacial polymerization according to the present invention prepared as described above (a) and ( As shown in b), the polyarylate according to the present invention is prepared by directly reacting an aromatic ester compound, dicarboxylic acid and dihydric phenol, and thus has no other impurities. Can be obtained.

In addition, although the manufacturing process according to the present invention has a three-step process, each process is very simple and convenient, and it is not only very easy to obtain a desired polymer compound, but also an average of 95% or more in terms of its yield. Since almost complete reaction takes place, a large amount of polymer can be obtained even in a small reactor, and it can be prepared to have a high molecular weight sufficient to be commercially available.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

EXAMPLE

The reaction was carried out in three steps. First, 0.1 mol of isophthalic chloride and 0.1 mol of terephthalic chloride are thoroughly stirred at about 100 ° C. and mixed well so that the two substances are evenly distributed. Here, 0.2 mol of bisphenol A is stirred well and mixed.

The first reaction proceeds while generating HCl gas. At this time, the reaction temperature is maintained at 130 ° C. and 1 minute later, nitrogen gas is flowed at a rate of 800 ml / min so that the generated HCl gas can be discharged from the reactor.

Until this time, the rotational speed of the stirrer is maintained at about 160 rpm. Immediately thereafter, the rotational speed is increased to about 800rpm, reacted for about 20 minutes, and then immediately increased to 197 ° C higher than the glass transition temperature.

At this time, the reactant is dark red color and continues to the secondary reaction at 197 ℃ until further stirring is impossible. It should be noted that the temperature of the nitrogen gas to be injected should be preheated at least up to 180 ° C and the rotational rpm is also lowered to about 160rpm.

The reaction is then very pale yellow, no longer agitated, stops stirring and remains at this temperature for about 2 hours. At this time, the nitrogen gas continues to flow to discharge the HCl gas out.

The next step is to raise the reactant to about 270 ° C. and continue flowing nitrogen gas and start stirring again when the reactant is soft and stirrable. In this reaction, it becomes possible to stir at about 240 degreeC or more, and it becomes possible to fully stir at 260 degreeC or more. At this time, if the stirring speed is too high, the reaction material rises up along the stirring shaft due to Weissenberg effects, making stirring impossible.

Therefore, it is safe to maintain the stirring speed of about 160rpm. Reaction at this stage for about 1 hour yields a pale yellow polyarylate. Thereafter, a vacuum pump is used to completely remove the HCl gas remaining in the reactants for 20 minutes, and the reaction mixture in the high temperature state is gradually cooled to terminate all reactions. As a result of measuring the I.V value of the obtained reactant, a polymer polyarylate having I.V = 0.612 was obtained.

Comparative Example 1

It carried out in the same manner as in Example 1 but the reaction conditions were carried out as shown in Table 1. The inherent viscosity of the resulting polyarylate was 0.604.

Comparative Example 2

It carried out in the same manner as in Example 1 but the reaction conditions were carried out as shown in Table 1. The resulting polyarylate had a somewhat low intrinsic viscosity (I.V) of 0.46. This is thought to be the result of the reaction temperature in the first and second reactions being too high and the third reaction not being carried out.

TABLE 1

* I.V. Is a value measured at 30 ° C by dissolving polymer 0.5 in 100 ml of phenol / tetrachloroethane (60/40 molar ratio).

As can be seen in Table 1, the polyarylate prepared by the melt polymerization method according to the present invention can be seen that the product is not inferior to the I.V value of 0.6 of the conventional product (trade name; U-100).

Claims (10)

In preparing the polyarylate by melt polymerization method, the reaction material of the dihydric kenol or its derivatives and the aromatic dicarboxylic acid or its derivatives can be directly reacted in three steps with different temperature ranges and reaction times. Method for producing a polyarylate characterized in that. The method of claim 1, wherein the first reaction in the reaction is carried out under the conditions of reaction temperature 120 ℃ ~ 140 ℃, reaction time 10 minutes ~ 30 minutes. The method of claim 1 or 2, wherein the first reaction is a method for producing a polyarylate, characterized in that the nitrogen gas is carried out under the condition of being injected at a rate of 800 ~ 1000ml / min. According to claim 1, wherein the secondary reaction in the reaction polya, characterized in that the reaction temperature is carried out at a temperature 1 ℃ ~ 10 ℃ higher than the glass transition temperature of the polyarylate, the reaction time is 1 to 2 hours Method of manufacturing the related. The method of claim 1 or 4, wherein the secondary reaction is carried out under the condition of injecting nitrogen gas of 180 ° C or more at an injection rate of 800 ml / min or more. The method of claim 1, wherein the tertiary reaction in the reaction is carried out under the conditions of the reaction temperature of 260 ℃ ~ 280 ℃, reaction time 40 ~ 70 minutes. The polyarylate according to claim 1 or 6, wherein the tertiary reaction is carried out under the condition of injecting nitrogen gas at a temperature of 250 ° C. or higher at an injection rate of 800 ml / min or more while stirring at a stirring speed of 120 to 180 rpm. Way. The dihydric phenol or a derivative thereof according to claim 1, wherein resorcinol, hydroquinone, diphenol, dihydroxynaphthalene, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxy) Phenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) sulfide, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) A method for producing a polyarylate, characterized by using an oxide, bis (4-hydroxyphenyl) sulfone or a C ₁ -C ₂ alkyl or halogen substituent thereof. The method of claim 1, wherein the aromatic dicarboxylic acid is terephthalic acid, isophthalic acid, dibenzoic acid, naphthalenedicarboxylic acid, bis (4-carboxyphenyl) methane, 1,2-bis (4-carboxyphenyl) ethane, , 2-bis (4-carboxyphenyl) propane, bis (4-carboxyphenyl) oxide, bis (4-carboxyphenyl) sulfide, bis (4-carboxyphenyl) sulfone or their C ₁ -C ₂ alkyl or halogen substituents Method for producing a polyarylate, characterized in that using at least one selected from. 10. The method according to claim 1 or 9, wherein the aromatic dicarboxylic acid is used at terephthalic acid and isophthalic acid at 70-50 mol% vs. 30-50 mol%.

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