JPH07118372A - Production of aromatic polyester - Google Patents

Abstract

PURPOSE:To industrially inexpensively obtain an aromatic polyester excellent in heat resistance, solvent resistance, etc., by reacting a specific compound with a dicarboxylic acid, hydroquinone, and a diaryl carbonate under special conditions. CONSTITUTION:A mixture of dicarboxylic acid ingredient (A) comprising 70-100mol% isophthalic acid, hydroquinone (B), a compound (C) represented by formula I (wherein R1 to R4 each is H or a 1-6C alkyl and R5 is a 1-10C hydrocarbon qroup), and a diaryl carbonate (D) is reacted in the presence of a compound represented by formula II (wherein R<12> and R<13> each is H, a 1-6C alkyl, a 5-10C cycloalkyl, or a 6-12C aryl or aralkyl and may be bonded to each other; R<14> is H or a 1-6C alkyl; and n is 1-4), the molar ratio of B/C being 50/50 to 80/20, the sum of B and C being 95-120mol% based on A, and the amount of D being 180-220mol% based on A. Thus, a noncrystalline aromatic polyester is obtained which has an intrinsic viscosity of 0.3 or higher (at 35 deg.C in a 60/40 by weight phenol/1,1,2,2-tetraethane mixed solvent).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an amorphous aromatic polyester. More specifically, it 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 having various characteristics such as an amorphous polymer, a crystalline polymer or a liquid crystalline polymer can be obtained depending on the combination or composition of its constituent components. Among these, amorphous polymers are excellent in dimensional stability, transparency, mechanical properties, and heat resistance, and have been variously studied as so-called amorphous engineering plastics. Particularly, a polymer using terephthalic acid and isophthalic acid as an acid component and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) as a diol component has a relatively balanced physical property. However, this polymer, like ordinary amorphous polymers, has insufficient solvent resistance, is easily dissolved or swelled in various organic solvents, and its use is limited. ing.

For the purpose of improving the solvent resistance, there has been proposed one in which hydroquinone is partially used as a diol component (JP-A-52-78999). The hydroquinone component-introduced polymer is certainly improved in solvent resistance and stress crack resistance as compared with a polymer using bisphenol A alone as a diol component. However, as its production method, the hydroquinone component is extremely susceptible to oxidation, the solubility of the polymer is insufficient, and the like. Therefore, the solution polymerization method or the interface used as the production method of bisphenol A alone is used. The polymerization method cannot be adopted.

Therefore, the above-mentioned JP-A-52-78999, JP-B-63-49610 and JP-B-63-4 are mentioned above.
According to Japanese Patent Publication No. 9611, production by a melt polymerization method is tried as a production method of a polymer having a hydroquinone component introduced therein. However, in this method, as described in the example, after solidifying or crystallizing the polymer in the melt polymerization process, the solid-state polymerization is subsequently carried out to produce the desired aromatic polyester. This is because the melt viscosity of the polymer is high at a relatively low melt polymerization temperature of about 300 ° C. or less, so that it is difficult to obtain a polymer having a high degree of polymerization capable of expressing sufficient toughness. This is considered to be due to the property that it can be crystallized. However, this method of using solid-phase polymerization in combination has a problem that the manufacturing process is complicated, the productivity is low, and the cost is high.

Further, as a method for obtaining a polymer by melt polycondensation, as disclosed in JP-A-60-53527, (a) a method of heating polycondensation using an aromatic dicarboxylic acid and a diphenol fatty acid diester as raw materials. As disclosed in JP-A No. 2-1732 and JP-A No. 3-24124, (b) an aromatic dicarboxylic acid,
Method of heating polycondensation using diphenol and aliphatic acid anhydride as raw materials, as disclosed in JP-A-58-47019, (c) Heat polycondensation using aromatic dicarboxylic acid diester and diphenol as raw materials how to,
(D) A method of heating and polycondensing aromatic dicarboxylic acid, diphenol and diaryl carbonate as raw materials can be mentioned. The methods (a) and (b) are relatively low in raw material cost and can produce a polymer, but a fatty acid or a fatty acid anhydride is distilled out during the polymerization reaction, so that it is necessary to have a facility-related measure. There is a drawback that the number of carboxylic acid terminals of the produced polymer tends to increase.
The methods (c) and (d) are slightly less costly than the methods (b) and (b), but they tend to give good polymers with fewer 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 so far that the polymer becomes yellowish or brownish.

As a method for improving such a problem, for example, in Japanese Patent Publication No. 3-128926, an aromatic dicarboxylic acid and an aromatic dicarboxylic acid and aromatic compound are prepared by 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.
Further, JP-A-4-236224 discloses 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 the rate of dissolution of the dicarboxylic acid component is limited. Therefore, the reaction must be carried out at a high temperature, and since it requires a long time, there is a limit to the improvement of hue. 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]

Therefore, the present inventors use solid phase polymerization in combination with an amorphous aromatic polyester having excellent heat resistance, solvent resistance, stress crack resistance, transparency and color tone. Moreover, it is another object of the present invention to provide a method for industrially inexpensively producing the dicarboxylic acid or diol directly from the dicarboxylic acid and the diol by a melt polymerization method without previously esterifying the dicarboxylic acid or diol.

[0009]

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

[0010]

[Chemical 3]

[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 these and (D) diaryl carbonate, the molar ratio (B / C) of a component (B) and a component (C) is 50 / 50-80 / 20,
The total amount of the component (B) and the component (C) is 95 to 120 mol% with respect to the component (A), and the component (D) is 1 with respect to the component (A).
The range is 80 to 220 mol%, and these are represented by the following formula (II).
Compound shown by

[0012]

[Chemical 4]

[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 having 6 to 12 carbon atoms or an aralkyl group. Further, there may be a bond between R ¹² and R ¹³ . R ¹⁴ is a hydrogen atom or a carbon number of 1 to
6 represents an alkyl group. n shows the integer of 1-4. ] Having an intrinsic viscosity of at least 0.3 (in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40), 35 ° C). 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 constituent components of the component (A) include aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid. Ingredient (A)
Of these, isophthalic acid is preferably 70 to 100 mol%.

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

[0016]

[Chemical 5]

[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]. ] The compound represented by these is used. In formula (I), R _{1 to} R ₄ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and specific examples thereof 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 preferable.

R ₅ is a hydrocarbon group having 1 to 10 carbon atoms, and more specifically, an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group can be mentioned. For more details,

[0019]

[Chemical 6]

Those having a structure such as can be exemplified. 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 preferable, and bisphenol A is particularly preferable.

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

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

Examples of the component (D) diaryl carbonate include diphenyl carbonate, di-p-tolyl carbonate, dinaphthyl carbonate, di-p-chlorophenyl carbonate and phenyl-p-tolyl carbonate. Of these, diphenyl carbonate Carbonate is particularly preferred. The diaryl carbonate may be substituted, may be used alone, or may be used in combination of two or more kinds.

The proportion of the component (D) used is 180 to 220 mol% relative to the component (A), and more preferably 1
90 to 210 mol%. If it is less than 180 mol%, the polymerization will be slow, which is not preferable, and if it is more than 220 mol%, the coloring of the polymer will be severe, which is not preferable.

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

[0026]

[Chemical 7]

[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 having 6 to 12 carbon atoms or an aralkyl group. Further, there may be a bond between R ¹² and R ¹³ . R ¹⁴ is a hydrogen atom or a carbon number of 1 to
6 represents an alkyl group. n shows the integer of 1-4. ] It is characterized in that it is heated and melted in the presence of.

In this reaction, firstly the diaryl carbonate mainly reacts with the dicarboxylic acid component and the diol component to produce phenols. Generally, since aromatic dicarboxylic acids have low solubility, it requires a high temperature to start the initial reaction and a long time to complete the initial reaction. However, when the above compound (II) is used, the initial generation of phenols is very low,
Moreover, it will be disclosed in a short time. Therefore, the time required for the reaction is shortened, and the hue of the resulting polymer is significantly improved. In addition, when the above compound (II) is used, sublimates generated during the reaction are significantly reduced.

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

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

In the present invention, it is preferable to use a conventionally known transesterification catalyst other than the above-mentioned compound (II) in combination. Examples of these transesterification catalysts include:
Examples thereof include carriers such as tin, antimony, strontium, zinc, cobalt, nickel, titanium, germanium, alkali metals and alkaline earth metals, oxides, hydroxides, halides, inorganic and organic acid salts and complex salts.

The polymerization temperature during the heat polycondensation is 280 to 4
It is necessary to set the temperature to 00 ° C. Here, the polymerization temperature means the temperature at the latter stage of 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, and if it is higher than 400 ° C., polymer deterioration or the like tends to occur, which is not preferable.

In the production method of the present invention, it is preferable that the polymerization reaction temperature is relatively low at the beginning and gradually raised to the above 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 is carried out under normal pressure and gradually reduced. At atmospheric pressure, it is preferable to use an atmosphere of an inert gas such as nitrogen or argon. The polycondensation reaction time is not particularly limited, but is about 1 to 10 hours.

The polyester of the present invention obtained by the above-mentioned production method has an intrinsic viscosity of 0.1 as measured at 35 ° C. in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40). It must be 3 or more. When the intrinsic viscosity is lower than 0.3, the heat resistance and toughness of the obtained polymer are insufficient, 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, for example, from the fact that its melting point is not detected by DSC.

When producing the aromatic polyester of the present invention, various additives such as stabilizers, colorants, pigments and lubricants may be added, if necessary.

[0037]

According to the production method of the present invention, an amorphous wholly aromatic polyester having excellent heat resistance, toughness, solvent resistance and excellent color tone is esterified with a dicarboxylic acid component or a diol component in advance. It is possible to obtain directly from the dicarboxylic acid and diol by a cheap melt polymerization process in a short time and with almost no sublimate.

[0038]

EXAMPLES The present invention will be described in detail below with reference to examples. In the examples, “parts” means “parts by weight”. The intrinsic viscosity was measured in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at a temperature of 35 ° C.
The heat and ward of the polymer were measured by DSC at a temperature rising rate of 10 ° C./min.

[Example 1] 16.6 parts of isophthalic acid,
8.47 parts hydroquinone, 7.52 parts bisphenol A, 42.8 parts diphenyl carbonate, 0.0
12 parts of 4-dimethylaminopyridine and 0.008 part of antimony trioxide were placed in a reactor having a vacuum distillation system equipped with a stirrer, and the inside of the vessel was replaced with nitrogen, and then the mixture was kept at normal pressure for 30 minutes.
The temperature was raised to 200 ° C over a period of time. Isophthalic acid was not dissolved at this point. After 40 minutes, the temperature was raised to 220 ° C., 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 temperature was gradually raised, the pressure was reduced, and the temperature was raised 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 produced sublimate was 0.4 parts. The polymer obtained has an intrinsic viscosity of 0.62 and a glass transition point of 176.
C and the color was light yellow.

[Example 2] 16.6 parts of isophthalic acid,
7.26 parts hydroquinone, 10.03 parts bisphenol A, 42.8 parts diphenyl carbonate, 0.
012 parts of 4-dimethylaminopyridine was put into a reactor having a vacuum distillation system equipped with a stirrer, and the inside of the container was replaced with nitrogen, and then the temperature was raised to 200 ° C. over 30 minutes under normal pressure. Isophthalic acid was not dissolved at this point. Four
After 0 minutes, 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. After that, the pressure was gradually reduced while reducing the pressure, and
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. Sublimate produced is 0.6
It was a department. The polymer obtained has an intrinsic viscosity of 0.53
The glass transition point was 175 ° C. and the color was pale yellow.

[Comparative Example 1] In place of 4-dimethylaminopyridine in Example 1, antimony trioxide was further added in an amount of 0.
The reaction was carried out in the same manner except that 004 parts were used, but isophthalic acid was still undissolved at the time of reaction at 240 ° C. for 20 minutes. When the temperature was gradually raised, isophthalic acid was dissolved after 15 minutes at 300 ° C. After that, the temperature is gradually raised and the pressure is reduced, and the temperature is increased to 320 minutes.
The temperature was raised to ° C. At that time, 0.3 mmHg in the reactor
The reaction was carried out for 30 minutes under the following high vacuum to obtain a polymer. The produced sublimate was 2.0 parts. The obtained polymer had an intrinsic viscosity of 0.64, a glass transition point of 176 ° C., and a yellow color.

[Comparative Example 2] The reaction was carried out in the same manner as in Example 1 except that 0.005 parts of sodium carbonate was used instead of 4-dimethylaminopyridine, but the reaction was carried out at 240 ° C.
After 20 minutes of reaction, isophthalic acid was still undissolved. When the temperature was gradually raised, isophthalic acid was dissolved after 10 minutes at 280 ° C. Thereafter, the temperature was gradually raised and the pressure was reduced, and the temperature was raised 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 produced sublimate was 1.5 parts. The polymer obtained had an intrinsic viscosity of 0.66, a glass transition point of 176 ° C., and a brown color.

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

Claims (1)

[Claims] 1. A dicarboxylic acid mainly comprising isophthalic acid, (B) hydroquinone, and [However, 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 these and (D) diaryl carbonate are the molar ratio (B / C) of a component (B) and a component (C) of 50 / 50-80 / 20, a component (B) and a component (C). The total amount is 95 to 120 with respect to the component (A)
Mol%, component (D) is 180 to 220 relative to component (A)
The content of these compounds is 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 of at least 0.3 (in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40), 35 ° C). For producing a crystalline aromatic polyester.