JP2831543B2 - Method for producing aromatic polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an amorphous aromatic polyester. More specifically, the present invention relates to a method for producing an amorphous aromatic polyester having excellent heat resistance, mechanical properties, solvent resistance, transparency and color tone.

[0002]

2. Description of the Related Art Aromatic polyesters can have various properties such as amorphous polymers, crystalline polymers or liquid crystalline polymers depending on the combination or composition of the constituent components. Among these, amorphous polymers are excellent in dimensional stability, transparency, mechanical properties, and heat resistance, and are variously studied as so-called amorphous engineering plastics. In particular, polymers using terephthalic acid and isophthalic acid as acid components and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) as diol components have relatively well-balanced physical properties. The development of this polymer has been promoted by taking advantage of this fact. However, this polymer, like ordinary amorphous polymers, has insufficient solvent resistance, easily dissolves or swells in various organic solvents, and its use is limited. ing.

[0003] For the purpose of improving the solvent resistance, there has been proposed a composition in which hydroquinone is partially used as a diol component (JP-A-52-78999). The polymer into which the hydroquinone component is introduced surely has improved solvent resistance and stress crack resistance as compared with those using only bisphenol A as the diol component. However, the production method of the hydroquinone component is extremely susceptible to oxidation or the solubility of the polymer is insufficient. No polymerization method can be employed.

Therefore, the above-mentioned Japanese Patent Application Laid-Open No. 52-78999, Japanese Patent Publication No. 63-49610, and Japanese Patent Publication No. Sho 63-4
According to Japanese Patent No. 9611, production by a melt polymerization method is attempted as a method for producing a polymer into which a hydroquinone component is introduced. However, in this method, as described in the Examples, the desired aromatic polyester is produced by solidifying or crystallizing the polymer in the melt polymerization process and then subjecting the polymer to solid phase polymerization. This is because at a relatively low melt polymerization temperature of about 300 ° C. or less, the melt viscosity of the polymer is high, so that it is difficult to obtain a polymer having a high degree of polymerization that can exhibit sufficient toughness. This is considered to be due to characteristics that can be crystallized. However, the method using the solid phase polymerization in combination has a problem that the production process is complicated, productivity is low, and cost is high.

Further, as a method for obtaining a polymer by melt polycondensation, as disclosed in JP-A-60-53527, (a) a method comprising heating and polycondensing an aromatic dicarboxylic acid and a diphenol fatty acid diester as raw materials. As disclosed in JP-A-2-1732 and JP-A-3-24124, (b) aromatic dicarboxylic acids,
A method of heating polycondensation using diphenols and aliphatic acid anhydrides as raw materials. As disclosed in JP-A-58-47019, (c) heating polycondensation using aromatic dicarboxylic acid diesters and diphenols as raw materials how to,
(D) A method in which aromatic polycarboxylic acids, diphenols, and diaryl carbonates are used as raw materials for heat polycondensation. The methods (a) and (b) can produce a polymer at a relatively low cost of raw materials, but require equipment measures because fatty acids or fatty acid anhydrides are distilled out during the polymerization reaction. There is a disadvantage that the number of carboxylic acid terminals of the produced polymer tends to increase.
The methods (c) and (d) are somewhat disadvantageous in raw material cost as compared with the methods (a) and (b), but tend to easily obtain a good polymer having few carboxylic acid terminals.

However, in any of the above methods, since the polymerization reaction is carried out at a temperature of 300 ° C. or higher, it has been a problem that the polymer takes on a yellow or brown color.

As a method for solving such a problem, for example, Japanese Patent Publication No. 3-128926 discloses an aromatic dicarboxylic acid and an aromatic dicarboxylic acid using a borane-tertiary amine complex salt compound and / or a quaternary ammonium borohydride compound as a catalyst. A method for producing an aromatic polyester by reacting a diol and a diaryl carbonate has been reported.
Japanese Patent Application Laid-Open No. 4-236224 reports a method for producing an aromatic polyester using a specific tin compound as a catalyst. However, in general, aromatic dicarboxylic acids have low solubility, and dissolution of the dicarboxylic acid component is rate-determining. Therefore, the reaction must be carried out at a high temperature. there were. Further, in the melt polymerization method, there is a problem that sublimates are generated during the polymerization reaction, and the cost is increased for removing them.

[0008]

Accordingly, the present inventors have developed a method of using an amorphous aromatic polyester having excellent heat resistance, solvent resistance, stress crack resistance, transparency and color tone together with solid phase polymerization. It is another object of the present invention to provide an industrially inexpensive method for producing a dicarboxylic acid and a diol directly from a dicarboxylic acid and a diol by a melt polymerization method without previously esterifying the dicarboxylic acid or the diol.

[0009]

The present invention provides (A) a dicarboxylic acid mainly composed of isophthalic acid, (B) a hydroquinone,

[0010]

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Wherein R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₅ represents a hydrocarbon group having 1 to 10 carbon atoms. The compound represented by the formula (I) and the diaryl carbonate (D), wherein the molar ratio (B / C) of the component (B) to the component (C) is 50/50 to 80/20;
The total amount of component (B) and component (C) is 95 to 120 mol% based on component (A), and component (D) is 1% based on component (A).
80 to 220 mol%, and these are represented by the following formula (II):
Compound represented by

[0012]

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[R ¹² and R ¹³ are each independently selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group or an aralkyl group having 6 to 12 carbon atoms. Further, there may be a bond between R ¹² and R ¹³ . R ¹⁴ is a hydrogen atom or carbon number 1
6 represents an alkyl group. n shows the integer of 1-4. Which has an intrinsic viscosity of 0.3 or more (35 ° C. in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at 35 ° C.), characterized by reacting in the presence of This is a method for producing a crystalline aromatic polyester.

In the present invention, a dicarboxylic acid mainly composed of isophthalic acid is used as the component (A). Examples of other components of the component (A) include aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. Component (A)
Of these, isophthalic acid is preferably 70 to 100 mol%.

Further, in the present invention, component (B) hydroquinone and component

[0016]

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Wherein R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₅ represents a hydrocarbon residue having 1 to 10 carbon atoms. ] Is used. In the formula (I), R _{1 to} R ₄ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and specific examples include a hydrogen atom, a methyl group, an ethyl group, and a t-butyl group. Of these, a hydrogen atom or a methyl group is preferred.

R ₅ is a hydrocarbon group having 1 to 10 carbon atoms, more specifically, an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group. More specifically,

[0019]

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Examples having such a structure can be given. Examples of the component (C) include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), and 2,2-bis (4 -Hydroxy-3,5-
Examples thereof include dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl) butane. Of these, bisphenol A and bisphenol Z are preferred, and bisphenol A is particularly preferred.

The ratio of the components (B) and (C) to be used is 50/50 to 80/20 in molar ratio (B / C). If the mole fraction of component (B) is less than 50%, the solvent resistance and stress rack resistance aimed at by the present invention are still insufficient, and if it is more than 80% by mole, the obtained polymer becomes crystalline. And the transparency becomes insufficient. The molar ratio (B / C) of component (B) to component (C) is preferably 5
5/45 to 75/25, particularly preferably 60/40 to 7
0/30.

In the process for producing an aromatic polyester of the present invention, the component (B) and the component (C) are added to the component (A).
Is in the range of 95 to 120 mol%. The total amount of component (B) and component (C) is preferably in the range of 97 to 115 mol%, and particularly preferably in the range of 99 to 110 mol%.

The component (D) diaryl carbonate includes, for example, diphenyl carbonate, di-p-tolyl carbonate, dinaphthyl carbonate, di-p-chlorophenyl carbonate, phenyl-p-tolyl carbonate and the like. Carbonates are particularly preferred. The diaryl carbonate may be substituted, used alone or in combination of two or more.

The proportion of component (D) used is from 180 to 220 mol%, preferably from 1 to 220 mol%, based on component (A).
90 to 210 mol%. If the amount is less than 180 mol%, the polymerization is slow, which is not preferable. If the amount is more than 220 mol%, the coloring of the polymer becomes intense, which is not preferable.

In the method of the present invention, the compound (A)
(B), (C) and (D) are compounds represented by the following formula (II)

[0026]

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[R ¹² and R ¹³ are each independently selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group or an aralkyl group having 6 to 12 carbon atoms. Further, there may be a bond between R ¹² and R ¹³ . R ¹⁴ is a hydrogen atom or carbon number 1
6 represents an alkyl group. n shows the integer of 1-4. ] In the presence of the compound.

In this reaction, first, a diaryl carbonate mainly reacts with a dicarboxylic acid component and a diol component to produce phenols. Generally, aromatic dicarboxylic acids have low solubility, so that high temperatures are required to initiate the initial reaction and long times are required to complete the initial reaction. However, when the compound (II) is used, the initial generation of phenols is very low temperature,
Moreover, it is disclosed in a short time. Therefore, the time required for the reaction is shortened, and the hue of the obtained polymer is remarkably improved. When the compound (II) is used, sublimates generated during the reaction are significantly reduced.

The amount of the compound (II) is not particularly limited, but is preferably about 0.01 to 1 mol% with respect to the component (A).

The compound represented by the above formula (II) includes
For example, 4-aminopyridine, 4-dimethylaminopyridine, 4-diethylaminopyridine, 4-pyrrolidinopyridine, 4-piperidinopyridine, 4-pyrrolinopyridine, 2-methyl-4-dimethylaminopyridine and the like can be mentioned. But among these, 4-dimethylaminopyridine,
4-Pyrrolidinopyridine is particularly preferred.

In the present invention, it is preferable to use a combination of a conventionally known transesterification catalyst other than the compound (II). As these transesterification catalysts, for example,
Carriers of tin, antimony, strontium, zinc, cobalt, nickel, titanium, germanium, alkali metals, alkaline earth metals, etc., oxides, hydroxides, halides, inorganic and organic acid salts, complex salts and the like can be mentioned.

The polymerization temperature during the heat polycondensation is from 280 to 4
It is necessary to be 00 ° C. Here, the polymerization temperature means a temperature at the end of the polymerization or at the end thereof. If the polymerization temperature is lower than 280 ° C., the melting temperature of the polymer becomes high, so that a polymer having a high degree of polymerization cannot be obtained.

In the production method of the present invention, it is preferable that the initial temperature of the polymerization reaction is relatively low, and the temperature is gradually raised to finally the above-mentioned polymerization reaction temperature. The reaction temperature of the polymerization reaction at this time is preferably 180 to 320 ° C. This polymerization reaction is carried out under normal pressure or under reduced pressure, but it is preferable that the initial polymerization reaction be carried out under normal pressure and gradually reduce the pressure. At the time of normal pressure, it is preferable to be in an atmosphere of an inert gas such as nitrogen or argon. The polycondensation reaction time is not particularly limited, but is generally about 1 to 10 hours.

The polyester of the present invention obtained by the above-mentioned production method has an intrinsic viscosity of 0.3 in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at 35 ° C. It is necessary to be 3 or more. If the intrinsic viscosity is lower than 0.3, the resulting polymer has insufficient heat resistance and toughness, which is not preferable.

The aromatic polyester of the present invention obtained by the above-mentioned production method is an amorphous polymer, and a transparent molded article can be obtained by a melt molding method such as injection molding. Further, the fact that the polymer of the present invention is amorphous can be confirmed by, for example, that the melting point is not detected by DSC.

In the production of the aromatic polyester of the present invention, various additives such as a stabilizer, a colorant, a pigment and a lubricant may be added as required.

[0037]

According to the production method of the present invention, an amorphous wholly aromatic polyester having excellent heat resistance, toughness and solvent resistance and a very good color tone is esterified with a dicarboxylic acid component or a diol component in advance. Without a sublimate, it can be obtained directly from a dicarboxylic acid and a diol by an inexpensive melt polymerization process in a short time and with almost no sublimation.

[0038]

The present invention will be described in detail with reference to the following Examples, in which "parts" means "parts by weight". The intrinsic viscosity was measured in a phenol / 1,1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at a temperature of 35 ° C.
The heat of the polymer and the administration were measured at a heating rate of 10 ° C./min using DSC.

Example 1 16.6 parts of isophthalic acid
8.47 parts of hydroquinone, 7.52 parts of bisphenol A, 42.8 parts of diphenyl carbonate, 0.0
12 parts of 4-dimethylaminopyridine and 0.008 part of antimony trioxide were put into a reactor having a vacuum distillation system equipped with a stirrer, and the atmosphere in the vessel was replaced with nitrogen.
The temperature was raised to 200 ° C. over a minute. At this point, the isophthalic acid was not dissolved. After 40 minutes, the temperature was raised to 220 ° C, and after reacting for 60 minutes, the temperature was raised to 240 ° C. After 20 minutes, all the isophthalic acid in the reactor had dissolved. afterwards,
The pressure was reduced while gradually increasing the temperature, and the temperature was increased to 320 ° C. over 90 minutes. At that time, the inside of the reactor was under a high vacuum of 0.3 mmHg or less, and the reaction was further performed for 30 minutes to obtain a polymer. The generated sublimate was 0.4 part. The resulting polymer has an intrinsic viscosity of 0.62 and a glass transition point of 176.
° C and the color was pale yellow.

Example 2 16.6 parts of isophthalic acid
7.26 parts of hydroquinone, 10.03 parts of bisphenol A, 42.8 parts of diphenyl carbonate,
012 parts of 4-dimethylaminopyridine was placed in a reactor equipped with a vacuum distillation system equipped with a stirrer, and the inside of the vessel was purged with nitrogen. At this point, the isophthalic acid was not dissolved. 4
0 minutes later, the temperature was raised to 220 ° C., and after reacting for 60 minutes, 240
The temperature was raised to ° C. After 20 minutes, all the isophthalic acid in the reactor had dissolved. Thereafter, the pressure was reduced while gradually increasing the temperature, and 9
The temperature was raised to 320 ° C. over 0 minutes. At that time, the inside of the reactor was under a high vacuum of 0.3 mmHg or less, and the reaction was further performed for 30 minutes to obtain a polymer. The generated sublimate is 0.6
Department. The intrinsic viscosity of the obtained polymer is 0.53
The glass transition point was 175 ° C. and the color was pale yellow.

[Comparative Example 1] In Example 1, antimony trioxide was further added in place of 4-dimethylaminopyridine.
The reaction was carried out in the same manner except that 004 parts were used. However, at the time when the reaction was carried out at 240 ° C. for 20 minutes, isophthalic acid was not dissolved. Then, when the temperature was gradually raised, the isophthalic acid was dissolved at 300 ° C. after 15 minutes. Thereafter, the pressure was reduced while gradually increasing the temperature, and the pressure was reduced to 320 over 90 minutes.
The temperature was raised to ° C. At that time, the inside of the reactor was 0.3 mmHg.
The reaction was carried out under the following high vacuum for further 30 minutes to obtain a polymer. The produced sublimate was 2.0 parts. The intrinsic viscosity of the obtained polymer was 0.64, the glass transition point was 176 ° C., and the color was yellow.

Comparative Example 2 A reaction was carried out in the same manner as in Example 1 except that 0.005 part of sodium carbonate was used instead of 4-dimethylaminopyridine.
At the time when the reaction was carried out for 20 minutes, the isophthalic acid was not yet dissolved. Then, when the temperature was gradually raised, the isophthalic acid was dissolved after 10 minutes at 280 ° C. Thereafter, the pressure was reduced while gradually increasing the temperature, and the temperature was increased to 320 ° C. over 90 minutes. At that time, the inside of the reactor was under a high vacuum of 0.3 mmHg or less, and the reaction was further performed for 30 minutes to obtain a polymer.
The generated sublimate was 1.5 parts. The intrinsic viscosity of the obtained polymer was 0.66, the glass transition point was 176 ° C., and the color was brown.

Comparative Example 3 The same reaction was carried out as in Example 2 except that 0.012 parts of 2-dimethylaminopyridine was used instead of 4-dimethylaminopyridine.
Even when the temperature was raised to 40 ° C., isophthalic acid did not dissolve.
Then, the temperature was raised to 260 ° C. and the reaction was continued for another 60 minutes, but the isophthalic acid was not dissolved.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-236224 (JP, A) JP-A-57-29427 (JP, A) JP-B-38-26299 (JP, B1) (58) Field (Int.Cl. ⁶ , DB name) C08G 63/00-63/91 C08G 64/00-64/42

Claims (1)

(57) [Claims] (A) a dicarboxylic acid mainly composed of isophthalic acid, (B) a hydroquinone, Wherein R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₅ represents a hydrocarbon group having 1 to 10 carbon atoms. The compound (B) and the component (B) and the component (C) have a molar ratio (B / C) of 50/50 to 80/20, and the component (B) and the component (C). The total amount is 95 to 120 based on the component (A).
Mol%, component (D) is 180 to 220 with respect to component (A)
% Of the compound represented by the following formula (II): [R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group or aralkyl group having 6 to 12 carbon atoms. Further, there may be a bond between R ¹² and R ¹³ . R ¹⁴ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. n shows the integer of 1-4. Having an intrinsic viscosity (35 ° C. in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at 35 ° C.) characterized by reacting in the presence of A method for producing a crystalline aromatic polyester.