JPH06228294A - Production of aromatic polyester - Google Patents

Abstract

PURPOSE:To obtain the subject polymer having good heat resistance, strength and solvent resistance by subjecting isophthalic acid to melt reaction with hydroquinone, 2,2-bis(4 hydroxyphenyl)propane and diaryl carbonate in the presence of a catalyst. CONSTITUTION:(A) Isophthalic acid, (B) hydroquinone, (C) 2,2-bis(4- hydroxyphenyl)propane and (D) diaryl carbonate are packed into a reactor equipped with a stirrer and a nitrogen introducing inlet and having a vacuum flow system in a molar ratio simultaneously satisfying formulas I to III and the reaction of these components is started in the presence of a catalyst such as antimony trioxide in a nitrogen stream at 240 deg.C and temperature of the reactor is raised to 340 deg.C over 3hr. Then, the pressure in the reactor is gradually reduced and these components are polymerized for 3hr under reduced pressure of 1mmHg to provide the objective amorphous wholly aromatic polyester having >=0.3 intrinsic viscosity [in phenol/1,1,2,2-tetrachloroethane mixed solvent (60/40 weight ratio) at 35 deg.C] and capable of providing good moldings having heat resistance, mechanical characteristics and solvent resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an amorphous aromatic polyester, and more specifically, an amorphous aromatic polyester giving a molded article having excellent heat resistance, mechanical properties and solvent resistance due to its melt moldability. The present invention relates to a method for producing a group polyester.

[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 the 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 the acid component and 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) as the diol component has a relatively balanced physical property. However, this is being utilized for development, but this polymer, like ordinary amorphous polymers, has insufficient solvent resistance, is easily dissolved or swelled in various organic solvents, and its use is limited. There is.

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, the production method thereof is such that the hydroquinone component is extremely susceptible to oxidation or the solubility of the polymer is insufficient. You cannot adopt legality.

Therefore, according to the above-mentioned Japanese Patent Application Laid-Open No. 52-78999, production by a melt polymerization method is tried as a production method of a polymer into which a hydroquinone component is introduced. However, in this method, as shown in the examples, the target aromatic polyester is produced by solidifying or crystallizing the polymer in the melt polymerization process and subsequently solid-phase polymerizing it. . This is because the melt viscosity of the polymer is high at a relatively low melt polymerization temperature of about 320 ° C. or less, so that it is difficult to obtain a polymer having a high degree of polymerization capable of expressing sufficient toughness. It is considered that this is because it has the property of crystallizing. However, the method of using this solid-state polymerization in combination complicates the manufacturing process,
Moreover, there is a problem that productivity is low and cost is high.

If a polymer is directly obtained from a dicarboxylic acid and a diol by such a melt polymerization method, it is not practical because the coloring is remarkable and the polymerization rate is small. Therefore, as an alternative to the method (1) in which the diaryl ester of the dicarboxylic acid component and the diol are reacted in advance, or the method (2) and the method (2) in which the dicarboxylic acid and the lower aliphatic carboxylic acid ester of the diol are reacted in advance. A method (3) of adding a lower aliphatic carboxylic acid anhydride when reacting a dicarboxylic acid and a diol is used. But,
In the methods (1) and (2), the raw material has to be esterified in advance, which causes a high cost. Further, in the methods (2) and (3), since a lower aliphatic carboxylic acid is generated during the reaction, the apparatus is easily corroded, and the obtained polymer has a problem that the terminal COOH concentration is high.

[0006]

Therefore, the present inventors have proposed that an amorphous polyester excellent in heat resistance, mechanical properties, solvent resistance, and stress crack resistance can be obtained without using solid phase polymerization in combination. Further, the present invention provides a method for industrially inexpensively producing a dicarboxylic acid or a diol directly from the dicarboxylic acid and the diol by a melt polymerization method without previously esterifying the dicarboxylic acid or the diol.

[0007]

According to the present invention, (A) isophthalic acid, (B) hydroquinone, (C) 2,2-bis (4-hydroxyphenyl) propane, and (D) diaryl carbonate are represented by the following formula ( I), (II) and (III)

[0008]

0.5 ≦ (B) / {(B) + (C)} ≦ 0.8 (I) 0.95 ≦ {(B) + (C)} / (A) ≦ 1.2 ( II) Intrinsic viscosity of 0.3 or more, which is characterized in that the resin is heated and melted in the presence of a catalyst at a molar ratio that simultaneously satisfies 1.8 ≦ (D) / (A) ≦ 2.3 (III). It is a method for producing an amorphous wholly aromatic polyester having (phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40, 35 ° C.)).

The molar ratio (B / C) of the component (B) and the component (C) is 50/50 to 80/20. If the mole fraction of the component (B) is less than 50%, the solvent resistance and stress crack resistance targeted by the present invention are still insufficient, and if it exceeds 80 mol%, the polymer obtained tends to be crystalline. Therefore, the transparency becomes insufficient. The molar ratio (B / C) of component (B) and component (C) is preferably 5
5/45 to 75/25, more preferably 60/40 to 7
It is 0/30. In the method for producing an aromatic polyester of the present invention, the total amount of the component (B) and the component (C) is in the range of 95 to 120 mol% with respect to the component (A). The total amount of component (B) and component (C) with respect to component (A) is 9
The range of 7 to 110 mol% is preferable, and the range of 99 to 105 mol% is particularly preferable. Also, the component (B)
And component (C) may be added to the reaction system from the beginning,
The components (A) and (D) may be appropriately reacted and then added to the system.

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

The molar ratio (D / A) of the use ratio of the component (D) to the component (A) is 1.8 to 2.3. When it is less than 1.8 or more than 2.3, the polymerization rate becomes low, which is not preferable. Ingredient (D) for ingredient (A)
The molar ratio (D / A) of the use ratio of is preferably 1.9 to
It is 2.3, and particularly preferably 2.0 to 2.3.

In the present invention, the above-mentioned components are heated and melt-polymerized in the presence of a catalyst. The catalyst used here is not particularly limited and conventionally known ones used in the production of polyester can be used, but examples thereof include metals such as sodium, potassium, tin, antimony, strontium, zinc, cobalt, nickel, titanium and germanium. Simple substance, oxide, hydroxide, halide, inorganic or organic acid salt, complex salt and the like. Particularly, antimony compounds, tin compounds and titanium compounds are preferable. The amount of the catalyst used is not particularly limited, but is preferably about 0.1 mol% or less with respect to the above component (A).

The polymerization temperature during the heat polycondensation is 340 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 340 ° C., the melt viscosity 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., the polymer is apt to deteriorate, 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 temperature. The reaction temperature of the initial polymerization reaction at this time is preferably 150 to 280 ° C, more preferably 180 to 250 ° 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 obtained by the present invention has an intrinsic viscosity of 0.3 or more measured at 35 ° C. in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40). is necessary. When the intrinsic viscosity is lower than 0.3, the heat resistance and toughness of the obtained polymer are insufficient, which is not preferable. Intrinsic viscosity 0.4-2.0
Is preferable, and 0.5 to 1.5 is particularly preferable.

The aromatic polyester obtained by the present invention is an amorphous polymer, and a transparent molded article can be obtained by melt molding such as injection molding. The fact that the polymer of the present invention is amorphous means that, for example, DS
It can be confirmed from the fact that the melting point cannot be obtained by C.

During the production of the aromatic polyester of the present invention, various stabilizers such as oxidation stabilizers and anti-coloring agents, and various additives such as colorants, pigments and lubricants may be added, if desired.

[0018]

According to the production method of the present invention, an amorphous wholly aromatic polyester having good heat resistance, toughness, solvent resistance and stress crack resistance is esterified with a dicarboxylic acid component or a diol component in advance. Can be directly produced from the dicarboxylic acid and diol without using solid phase polymerization by an inexpensive melt polymerization process,
In addition, it is possible to carry out the reaction without adding a compound such as a lower aliphatic carboxylic acid that causes corrosion of the apparatus during the polymerization, and the advantage that the obtained polymer is a good polymer without the problem that the terminal COOH concentration is high Have

[0019]

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 concentration of 1.2 g / dl and a temperature of 35 ° C. The thermal characteristics of the polymer were measured by DSC at a temperature rising rate of 10 ° C./min. Specific gravity is AST
It was measured according to MD 1505. Heat distortion temperature is AST
It was measured according to MD648. Tensile strength and elongation at break were measured according to ASTM D638, and bending strength and flexural modulus were measured according to ASTM D790. Impact strength was measured according to ASTM D256. Chemical resistance is
After immersing the sample in the solvent for 24 hours, it was observed and evaluated.

Example 1 Isophthalic acid 996 parts, hydroquinone 462 parts, bisphenol A 410 parts, diphenyl carbonate 2632 parts, antimony trioxide 0.
52 parts were placed in a reaction vessel having a vacuum outflow system equipped with a stirrer and a nitrogen inlet, the reaction was started at 240 ° C. in a nitrogen stream under normal pressure, and the temperature was raised to 340 ° C. over 3 hours, then to the same temperature The pressure was gradually reduced to about 1 mmHg after 1 hour. During this period, phenol was generated and distilled off. Polymerization was performed under the same conditions for about 3 hours to obtain a polymer. The obtained polymer was light brown and transparent, and the intrinsic viscosity was 0.66. The glass transition temperature was 174 ° C.

Next, this polymer was injection molded using an injection molding machine at a cylinder temperature of 340 ° C. and a mold temperature of 100 ° C. Table 1 shows the physical properties of the obtained molded product.

Example 2 Diphenyl carbonate was added to 2
340 ° C. in the same manner as in Example 1 except that 568 parts were used.
It was set to about 1 mmHg. Polymerization was carried out under these conditions for 6 hours to obtain a polymer. The obtained polymer is light brown transparent,
The intrinsic viscosity was 0.68. Glass transition temperature is 175
It was ℃.

[Example 3] Two diphenyl carbonates were used.
840 parts by the same manner as in Example 1 except that 824 parts were used.
It was set to about 1 mmHg. Polymerization was carried out for 5 hours under these conditions to obtain a polymer. The obtained polymer is light brown transparent,
The intrinsic viscosity was 0.64. Glass transition temperature is 170
It was ℃.

According to the present invention, it is possible to produce an amorphous aromatic polyester having excellent heat resistance, mechanical properties and solvent resistance as shown in Table 1 without requiring complicated operations. Recognize.

Example 4 Diphenyl carbonate was added to 2
340 ° C. in the same manner as in Example 1 except that 314 parts were used.
It was set to about 1 mmHg. Polymerization was carried out under these conditions for 4 hours to obtain a polymer. The obtained polymer is light yellowish brown,
The intrinsic viscosity was 0.59. Glass transition temperature is 168
It was ℃.

[0026]

[Table 1]

Claims (1)

[Claims] 1. A) isophthalic acid, (B) hydroquinone, (C) 2,2-bis (4-hydroxyphenyl)
Propane and (D) diaryl carbonate are represented by the following formulas (I), (II) and (III): 0.5 ≦ (B) / {(B) + (C)} ≦ 0.8 (I) 0.95 ≦ {(B) + (C)} / (A) ≦ 1.2 (II) 1.8 ≦ (D) / (A) ≦ 2.3 (III) at the same molar ratio, Intrinsic viscosity of 0.3 or more (in phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40), 35 ° C.), which is characterized by reacting by heating and melting in the presence of a catalyst. A method for producing an amorphous wholly aromatic polyester having the same.