JP2001114876A - Aromatic polyester and its formed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aromatic polyester composed of structural units represented by formulas (1) to (5) and processing both sufficient rigidity and heat resistance. SOLUTION: Contents (r1) to (r5) of the respective structural units of formulas (1) to (5) in the aromatic polyester are set as follows when (rt) is the total of the contents of the structural units (1) to (5): 30%<=(r1)/(rt)<=50%; 2.7<=(r2)/(r3)<=4; and 1.0<=(r4)/(r5)<=1.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an aromatic polyester and a molded article thereof.

[0002]

2. Description of the Related Art As aromatic polyesters, aromatic polyesters comprising the following structural units (1), (2), (3), (4) and (5) are widely known. I have. [In the formulas (1) to (5), R _a , R _b , R _c , R _d ,
R _e and R _f each independently represent a lower alkyl group, a lower alkoxyl group, a phenyl group, an aryloxy group or a halogen atom; g, h, k, m, n and p each independently represent 0 to 3; Indicates an integer. ]

Since such an aromatic polyester molded article is used as, for example, an electric component or an electronic component, it is desirable that the molded article has both rigidity and heat resistance to solder.

The aromatic polyester which can be formed into a molded article having the above-mentioned structural units (1) to (5) and having excellent heat resistance to solder is exemplified by the content (r ₂ ) of the structural unit ( ₂ ) and the structural unit (3) ) With the content (r ₃ ) of (r ₂ / r ₃ ) is 1.0, and the content (r ₄ ) of the structural unit ( ₄ ) and the content (r ₅ ) of the structural unit ( ₅ ) Ratio (r ₄ / r ₅ ) to 2.
No. 33 is known (JP-A-63-57633). However, a molded article made of such an aromatic polyester has a problem that rigidity is inferior.

[0005] On the other hand, as an aromatic polyester comprising the above structural units (1) to (5) and capable of forming a molded article having excellent rigidity, (r ₂ / r ₃ ) is 5.0 and (r ₄ / r ₃ ) An aromatic polyester having an r ₅ ) of 0.31 is known (JP-A-60-38425). However, there has been a problem that a molded article made of such an aromatic polyester is inferior in heat resistance to solder.

As described above, the conventional structural units (1) to (5)
The aromatic polyester composed of (5) could not provide a molded article having both the rigidity and heat resistance required for use as an electric component or the like.

[0007]

The present inventors have been keen to develop an aromatic polyester comprising the above structural units (1) to (5) and having a sufficient rigidity and heat resistance. As a result of the study, (r ₂ / r ₃ ) was changed to 2.7.
It has been found that an aromatic polyester having a ratio of not less than 4 and a ratio of (r ₄ / r ₅ ) of not less than 1.0 and not more than 1.5 can provide a molded article having sufficient rigidity and excellent heat resistance to solder. This has led to the present invention.

[0008]

That is, the present invention comprises the above structural unit (1), structural unit (2), structural unit (3), structural unit (4) and structural unit (5). the content of the content (r ₁₎ is, the content of the structural unit (1) (r _1), the content of the structural unit (2) (r _2), the structural unit (3) of 1) (r _3), the content of the structural unit ₍₄₎ (r 4) and the content of the structural unit ₍₅₎ (r 5) the total amount (r _t) is 50% to 30% or more or less with respect to the, r ₂ and r
₃ and the ratio of (r ₂ / r ₃₎ is 2.7 to 4, wherein the ratio of r ₄ and _{r 5 (r 4 / r 5} ) of 1.0 to 1.5 Aromatic polyester (provided that r ₁ ,
r ₂ , r ₃ , r ₄ and r ₅ are the contents indicated by the substance ratios, respectively. ).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic polyester of the present invention comprises
It comprises the above structural units (1) to (5). Structural unit (1)
In R _a , R _b , R _c , R _d , R _e , and R _f in (5), examples of the lower alkyl group include an alkyl group having about 1 to 4 carbon atoms such as a methyl group, an ethyl group, and a propyl group. Is exemplified. Examples of the lower alkoxyl group include an alkoxyl group having about 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a t-butoxy group. Examples of the aryloxy group include a phenoxy group. Examples of the halogen atom include a chlorine atom and a bromine atom. g, h, k,
m, n and p each independently represent an integer of 0 to 3, preferably 0.

The aromatic polyester of the present invention comprises such structural units (1) to (5). The content of the structural unit (1) is determined by the content of the structural unit (2) (r ₂ ) and the structural unit ( the content of ₃₎ (r 3), the content of the structural unit ₍₄₎ (r 4) and the content of the structural unit ₍₅₎ (r 5 the total amount of) (r _t) with respect to 30% or more 50% It is as follows. The content of the structural unit (1) ~ (5) ( r 1 ~r 5) is a value represented by the amount of substance ratio (molar ratio). If r ₁ is less than 30%, it becomes difficult to mold the aromatic polyester,
Rigidity and heat resistance tend to decrease, preferably 3
5% or more. If r ₁ exceeds 50%, the aromatic polyester tends to be difficult to mold and the heat resistance tends to decrease.

[0011] The ratio of the content of the structural unit (2) and (r ₂₎ content of the structural unit (3) and (r ₃₎ ((r ₂ / r ₃₎ 2.
7 or more and 4 or less. If the ratio (r ₂ / r ₃ ) is less than 2.7, the rigidity tends to be insufficient, and preferably 2.
8 or more. If the ratio (r ₂ / r ₃ ) exceeds 4, the heat resistance tends to decrease.

The content of the structural unit (4) (r_Four) And structural unit
(R) content (r_Five) And the ratio (r _Four/ R_Five) Is 1.0
It is 1.5 or less. The ratio (r_Four/ R_Five) Is less than 1.0
Stiffness tends to be insufficient, and the ratio (r
_Four/ R_Five) Exceeds 1.5 makes molding difficult and heat resistance
Tends to decrease.

In the aromatic polyester of the present invention, the content (r ₂ ) of the structural unit ( ₂ ), the content (r ₃ ) of the structural unit ( ₃ ), the content (r ₄ ) of the structural unit ( ₄ ) and The content (r ₅ ) of the structural unit (5) usually satisfies the formula (I) 0.9 ≦ (r ₂ + r ₃ ) / (r ₄ + r ₅ ) ≦ 1.1 (I).

The flow start temperature of the aromatic polyester of the present invention is usually from 250 ° C. to 400 ° C., preferably from 2 ° C.
70 ° C. or more and 370 ° C. or less. Here, the flow start temperature is 100 kg / cm using a capillary rheometer equipped with a die having an inner diameter of 1 mm and a length of 10 mm.
² Temperature rise rate 4 ° C under load of 9.807MPa
/ Minute when extruding the aromatic polyester from the nozzle
It is a temperature at which the melt viscosity shows 48,000 poise (4800 Pa · s).

The aromatic polyester of the present invention includes, for example, p-hydroxybenzoic acids represented by the following general formula (6):
Hydroquinones represented by general formula (7), general formula (8)
4,4'-dihydroxybiphenyls represented by the general formula (9) and terephthalic acids represented by the general formula (1)
It can be produced by the method of condensation polymerization of isophthalic acids shown in 0). [In the formulas (6) to (10), R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a lower acyl group, and R ² , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydroxyl group, a lower alkoxyl group, an aryloxy group or a halogen atom. _Ra , _Rb , _Rc , _Rd , _Re ,
R _f , g, h, k, m, n and p each have the same meaning as described above. ]

R ¹ in the general formulas (6) to (10),
In R ³ , R ⁴ , R ⁵ and R ⁶ , the same substituents as described above are exemplified as the lower alkoxyl group, the aryloxy group and the halogen atom, and the lower acyl group is an acetyl group, a propionyl group, a benzoyl group. And the like.

Examples of the p-hydroxybenzoic acids (6) include, for example, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, p-acetoxybenzoic acid, methyl p-acetoxybenzoate,
-Ethyl acetoxybenzoate, propyl p-hydroxybenzoate, phenyl p-hydroxybenzoate, benzyl p-hydroxybenzoate and the like, among which p-hydroxybenzoic acid and p-acetoxybenzoic acid are preferably used.

Examples of the hydroquinones (7) include hydroquinone and 1,4-diacetoxybenzene. Examples of 4,4′-dihydroxybiphenyls (8) include 4,4′-dihydroxybiphenyl,
4,4'-diacetoxybiphenyl and the like.
Examples of the terephthalic acids (9) include terephthalic acid,
And dimethyl terephthalate. Examples of the isophthalic acids (10) include, for example, isophthalic acid, dimethyl isophthalate, and the like.

Such p-hydroxybenzoic acids (6),
For condensation polymerization of hydroquinones (7), 4,4′-dihydroxybiphenyls (8), terephthalic acids (9) and isophthalic acids (10), for example, p-hydroxybenzoic acids (6), hydroquinones (7) ), 4,4 '
A mixture of dihydroxybiphenyls (8), terephthalic acids (9) and isophthalic acids (10) may be heated.

Since polycondensation proceeds stoichiometrically, the content (r ₁ ) of the structural unit ( ₁ ), the content (r ₂ ) of the structural unit ( ₂ ), and the structural unit The content (r ₃ ) of ( ₃ ), the content (r ₄ ) of structural unit ( ₄ ) and the content (r ₅ ) of structural unit ( ₅ ) are respectively the amount of p-hydroxybenzoic acid (6) used ( s _6),
The amount of hydroquinone (7) used (s ₇ ), the amount of 4,4′-dihydroxybiphenyl (8) used (s ₈ ), the amount of terephthalic acid (9) used (s ₉ ) and isophthalic acid (10) (S ₁₀ ). Accordingly, s ₆ is appropriately selected depending on r ₁ to r ₅ of the target aromatic polyester.
May be selected ~s _10, specifically, s ₆ is, s _6, s
30% based on the total amount (s _t ) of ₇ , s ₈ , s ₉ and s ₁₀
Not less than 50%, and the ratio of s ₇ to s ₈ (s ₇ / s ₈ ) is not less than 2.7 and not more than 4, preferably not less than 2.8, and s ₉
And the ratio of s ₁₀ (s ₉ / s ₁₀ ) is 1.0 or more and 1.5 or less. Further, s ₇ ~s ₁₀ typically satisfies the formula _{(II) 0.9 ≦ (s 7} + s 8) / (s 9 + s 10) ≦ 1.1 (II). Incidentally, the amount of each compound (s _6, s _7,
s ₈ , s ₉ and s ₁₀ ) are the substance ratios (molar ratios)
Is the value indicated by.

As p-hydroxybenzoic acids (6), R
^When a compound in which ¹ is a hydrogen atom is used, condensation polymerization is usually carried out by heating together with an acylating agent while replacing the hydrogen atom of the compound represented by R ¹ with an acyl group. When a compound in which at least one of R ^{3 and} R ⁴ is a hydrogen atom is used as hydroquinone (7), the compound is usually heated with an acylating agent to convert the hydrogen atom represented by R ³ or R ⁴ of the compound. Polycondensation is carried out while substituting with an acyl group. 4,
When a compound in which at least one of R ^{5 and} R ⁶ is a hydrogen atom is used as the 4′-dihydroxybiphenyl (8), the compound is usually heated together with an acylating agent and represented by R ⁵ or R ⁶ of the compound. The polycondensation is carried out while replacing the hydrogen atom to be obtained with an acyl group. Examples of the acylating agent include carboxylic anhydride such as acetic anhydride.

During the polycondensation, a carboxylic acid such as acetic acid is produced as a by-product. The polycondensation is carried out while distilling off the by-produced carboxylic acid. Further, when an acylating agent is used, unreacted acylating agent volatilizes, but condensation polymerization may be carried out while distilling off the unreacted acylating agent. The condensation polymerization temperature is usually from 250 ° C to 400 ° C.

The condensation polymerization may be performed in the presence of a catalyst,
As the catalyst, for example, oxides of metals such as germanium, tin, titanium, antimony, cobalt, manganese,
Organic salts such as acetates and oxalates are exemplified. When such a catalyst is used, the amount used is, for example, p-hydroxybenzoic acid (6), hydroquinone (7), 4,
Total amount of 4'-dihydroxybiphenyls (8), terephthalic acids (9) and isophthalic acids (10) 100
0.001 to 1 part by weight per part by weight. The rate of polycondensation can be increased by performing polycondensation in the presence of a catalyst.

The polycondensate after polycondensation may be further subjected to solid phase polymerization. By performing solid phase polymerization, the degree of polymerization of the obtained aromatic polyester can be increased. For the solid phase polymerization, for example, the condensation polymerization product after the condensation polymerization may be cooled, pulverized, and further heated. The heating is carried out while the polycondensate after the polycondensation is kept in a solid state, and the heating temperature is usually 230 ° C. or more and 370 ° C. or less. The heating is usually performed under reduced pressure or an atmosphere of an inert gas such as nitrogen gas.

The flow start temperature of the obtained aromatic polyester can be controlled by adjusting the reaction temperature and reaction time in the condensation polymerization and solid phase polymerization, the rate of distilling off carboxylic acid and the like by-produced in the condensation polymerization reaction, and the like. For example, if the reaction time in the solid phase polymerization is shortened, an aromatic polyester having a low flow start temperature can be obtained, and if the reaction time is long, an aromatic polyester having a high flow start temperature can be obtained.

In the aromatic polyester of the present invention thus obtained, the structural unit (1) is derived from p-hydroxybenzoic acid (6), the structural unit (2) is derived from hydroquinone (7), and the structural unit ( 3) is 4,4'-
It is derived from dihydroxybiphenyls (8), the structural unit (4) is derived from terephthalic acids (9), and the structural unit (5) is derived from isophthalic acids (10).

Since the aromatic polyester of the present invention thus obtained is excellent in rigidity and heat resistance against solder, the molded article is useful as, for example, an electric component. The molded article of the aromatic polyester can be obtained, for example, by molding the aromatic polyester of the present invention by a usual molding method such as an injection molding method, an extrusion molding method, a compression molding method, and a blow molding method.

The molded article made of the polyester of the present invention may contain additives, other thermoplastic resins and the like. As additives, for example, inorganic fillers, fluororesins, release improvers such as metal soaps, nucleating agents, antioxidants,
Stabilizers, plasticizers, coloring inhibitors, coloring agents, UV absorbers,
Examples include an antistatic agent, a lubricant, and a flame retardant.

Examples of the inorganic filler include glass fibers such as milled glass fibers and chopped glass fibers, glass beads, hollow glass spheres, glass powder, mica, talc, clay, silica, alumina, potassium titanate, wollastonite, and heavy metals. Calcium carbonate such as calcium carbonate, light calcium carbonate, colloidal calcium carbonate, magnesium carbonate, basic magnesium carbonate, sodium sulfate, calcium sulfate, barium sulfate, calcium sulfite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium silicate , Silica sand, silica, quartz, titanium oxide, zinc oxide, iron oxide graphite, molybdenum, asbestos, silica alumina fiber, alumina fiber, gypsum fiber, carbon fiber, carbon black, white carbon, keiso Inorganic fillers such as soil, bentonite, sericite, shirasu, and graphite; metal whiskers such as potassium titanate whiskers, alumina whiskers, aluminum borate whiskers, silicon carbide whiskers, and silicon nitride whiskers; No.

The inorganic filler may have been subjected to a surface treatment. The surface treatment is performed by, for example, a method of adsorbing the surface treatment agent on the surface of the inorganic filler, a method of adding the surface treatment agent and kneading the inorganic filler and the aromatic polyester. As the surface treatment agent, for example, a silane coupling agent, a titanate coupling agent, a reactive coupling agent such as a borane coupling agent, a higher fatty acid,
Lubricants such as higher fatty acid esters, metal salts of higher fatty acids, and fluorocarbon-based surfactants are exemplified. These inorganic fillers may be used alone or in combination of two or more. Among such inorganic fillers, glass fiber, glass powder, mica, talc, carbon fiber and the like are preferably used. When an inorganic filler is used, the amount is usually about 400 parts by weight or less based on 100 parts by weight of the aromatic polyester.

Examples of other thermoplastic resins include polycarbonate resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyphenylene ether resin, polyether ketone resin, and polyetherimide resin.

A molded article containing an additive, another thermoplastic resin, etc. is, for example, an aromatic polyester composition containing the aromatic polyester of the present invention and an additive, a thermoplastic resin, etc., for example, an aromatic polyester composition of the present invention. And an aromatic polyester composition comprising an inorganic filler. The aromatic polyester composition is produced, for example, by melt-kneading an aromatic polyester with a thermoplastic resin, additives, and the like in a kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, a Brabender, or a kneader. it can. Mortar, Henschel mixer, ball mill, using a blender such as a ribbon blender, after mixing the aromatic polyester and thermoplastic resin, additives, etc., and then fed to the same kneading machine as described above to melt and knead Can also produce aromatic polyester compositions. When an aromatic polyester is produced by condensation polymerization, an additive or the like may be added for condensation polymerization.

When the obtained aromatic polyester composition is produced by melt-kneading, the aromatic polyester composition is kept in a molten state immediately after melt-kneading in a molding machine such as an extruder, an injection molding machine, a compression molding machine or a blow molding machine. What is necessary is just to supply and shape | mold. An aromatic polyester, an additive, a thermoplastic resin, and the like may be supplied to a molding machine, and may be melted and molded in the molding machine. Alternatively, the cooled aromatic polyester composition may be heated again, melted and supplied to a molding machine for molding, or the cooled aromatic polyester composition may be supplied to the molding machine and melted in the molding machine. And may be molded. The shape of the molded body is not particularly limited.

The molded body thus obtained is excellent in rigidity and heat resistance to solder. In addition, it has excellent mechanical properties, electrical properties, chemical resistance, and oil resistance, so it is useful as electrical parts and electronic parts, and specifically useful as switches, coil bobbins, relays, connectors, sockets, etc. It is also useful as a film- or sheet-like electric component such as a display device component, an electrical insulating film, a film for a flexible circuit board, or an electronic component. In addition, the molded article made of the aromatic polyester of the present invention includes mechanical parts such as gears, bearings, and motor parts, printers, copiers, facsimiles, VCRs, video cameras, floppy (registered trademark) disk drives, and hard disks. Drives, CD-ROM drives, magneto-optical disk drives and other office equipment and information equipment components, IC trays, semiconductor process related equipment such as wafer carriers, microwave cooking pots, cooking utensils such as oven heat-resistant dishes, etc. It is useful as a film-shaped or sheet-shaped molded article such as a molded article having a complicated shape, a molded article having a complicated shape, a film for packaging, and a film for a recording medium. Further, a molded article formed into a fibrous form such as continuous fiber, short fiber, or pulp is useful as clothing, heat-insulating material, reinforcing material for FRP, rubber reinforcing material, rope, cable, nonwoven fabric, and the like.

[0035]

The aromatic polyester of the present invention can provide a molded article having excellent rigidity and heat resistance to solder.

[0036]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The test pieces obtained in Examples and Comparative Examples were evaluated by the following methods. (1) Moldability In each of the examples and comparative examples, a test piece having a shape corresponding to the shape of the mold cavity was obtained, and a test piece having a shape corresponding to the shape of the mold cavity was designated as ○. Those that could not be obtained were evaluated as x. (2) Flexural modulus The test piece (12.7 mm ×
6.4 mm x 127 mm) and ASTM D790
A bending test was performed in accordance with. (3) Solder heat resistance temperature Dumbbell-shaped test pieces obtained in each of Examples and Comparative Examples [JIS
K7113 (1/2)] was immersed in a solder bath kept at 230C to 300C at 5C intervals for 60 seconds. The maximum temperature at which no deformation of the test piece or generation of blisters (swelling due to internally generated gas) was observed was taken as the solder heat resistant temperature.

Example 1 (Production of Aromatic Polyester) 525 parts by weight (38 mol%) of p-hydroxybenzoic acid (compound 1) was placed in a vessel equipped with a reflux condenser, a thermometer, a nitrogen inlet tube and a stirring rod. 273 parts by weight of hydroquinone (compound 2) (24.
8 mol%), 116 parts by weight of 4,4'-dihydroxybiphenyl (compound 3) (6.20 mol%), 281 parts by weight of terephthalic acid (compound 4) (16.91 mol%), isophthalic acid (compound 5) After charging 234 parts by weight (14.09 mol%) and 1123 parts by weight (110 mol%) of acetic anhydride, the temperature was raised to about 140 ° C.
Stirred for hours. Thereafter, acetic acid was distilled off while the temperature was raised to about 320 ° C., and the temperature was further kept at about 320 ° C. for 1 hour to obtain 1246 parts by weight of a prepolymer.

After cooling the obtained prepolymer, it was pulverized by a pulverizer, and then the gas phase temperature in the oven was raised to 250 ° C. in a hot air circulation oven under nitrogen. After the temperature was raised from 250 ° C. to 280 ° C. over 5 hours, the temperature was kept at 280 ° C. for 3 hours, and the flow start temperature was 315 ° C.
1240 parts by weight of a polyester having a temperature of 100 ° C were obtained.

(Production of molded article) After mixing 600 parts by weight of the obtained aromatic polyester and 400 parts by weight of chopped glass fiber (CS03JAPx-1 manufactured by Asahi Fiberglass Co., Ltd.) with a Henschel mixer, a twin-screw extruder ( Granulation was performed at a cylinder temperature of 340 ° C. using Ikekai Iron Works Co., Ltd. PCM-30 type) to obtain pellets.

After drying the above pellets at 120 ° C. for 3 hours, an injection molding machine (PS40E5A manufactured by Nissei Plastic Industry Co., Ltd.) was used.
(SE type), injection molding at 340 ° C. cylinder temperature and 130 ° C. mold temperature, 12.7 mm × 6.4 mm
A × 127 mm test piece was obtained and injection molded in the same manner to obtain a dumbbell-type test piece [JIS K7113 (1/2)].

Examples 2 to 4 and Comparative Examples 1 to 5 p-hydroxybenzoic acid (compound 1), hydroquinone (compound 2), 4,4'-dihydroxybiphenyl (compound 3), terephthalic acid (compound 4) and isophthalic acid An aromatic polyester was obtained in the same manner as in Example 1 except that the amount ratio of the acid (compound 5) used was as shown in Table 1, and the resulting pellets were molded into test pieces and dumbbell-shaped test pieces. Obtained. Table 1 shows the evaluation results. Comparative Example 1
However, in injection molding, the mold could not be completely filled with the aromatic polyester, and a test piece having the shape of the cavity of the mold could not be obtained.

[0043]

[Table 1]

Comparative Examples 6 to 11 of p-hydroxybenzoic acid (compound 1), hydroquinone (compound 2), 4,4'-dihydroxybiphenyl (compound 3), terephthalic acid (compound 4) and isophthalic acid (compound 5) An aromatic polyester was obtained in the same manner as in Example 1 except that the used amount ratio was as described in Table 2, and the pellet was molded to obtain a test piece and a dumbbell-type test piece. Table 2 shows the evaluation results. Comparative Example 1
In the case of 0, the mold could not be completely filled with the aromatic polyester in the injection molding, and a test piece having the shape of the cavity of the mold could not be obtained.

[0045]

[Table 2]

Claims (7)

[Claims] 1. A structural unit (1), a structural unit (2), a structural unit (3), a structural unit (4) and a structural unit (5), and the content (r ₁ ) of the structural unit ( ₁ ) Is the content of the structural unit (1) (r ₁ ), the content of the structural unit (2) (r ₂ ), the content of the structural unit (3) (r ₃ ), and the content of the structural unit (4) ( r ₄₎ and the content of the structural unit (5) (the total amount of r ₅₎ (r _t) is less than or equal to 50% to 30% or more with respect to the ratio of r ₂ and r ₃ (r ₂ / r ₃₎ Is at least 2.7 and at most ₄ , and the ratio of r ₄ to r ₅ (r ₄ / r ₅ ) is at least 1.0 and at most 1.5 and is an aromatic polyester (provided that r ₁ , r ₂ , r ₃ , r ₄ and r ₅ are the contents indicated by the substance ratios, respectively.) [In the formulas (1) to (5), R _a , R _b , R _c , R _d ,
R _e and R _f each independently represent a lower alkyl group, a lower alkoxyl group, a phenyl group, an aryloxy group or a halogen atom; g, h, k, m, n and p each independently represent 0 to 3; Indicates an integer. ] 2. A p-hydroxybenzoic acid represented by the following general formula (6), a hydroquinone represented by the general formula (7), a 4,4'-dihydroxybiphenyl represented by the general formula (8), a general formula The method for producing an aromatic polyester according to claim 1, wherein the terephthalic acid represented by (9) and the isophthalic acid represented by the general formula (10) are polycondensed. [In the formulas (6) to (10), R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a lower acyl group, and R ² , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydroxyl group, a lower alkoxyl group, an aryloxy group or a halogen atom. _Ra , _Rb , _Rc , _Rd , _Re ,
R _f , g, h, k, m, n and p each have the same meaning as described above. ] 3. The amount of p- hydroxybenzoic acid represented by the general formula (6) (s _6), the amount of p- hydroxybenzoic acid represented by the general formula (6) (s _6), the general formula The amount (s ₇ ) of the hydroquinone represented by ( ₇ ), the amount (s 8) of the 4,4′-dihydroxybiphenyl represented by the general formula ( ₈ ), and the terephthalic acid represented by the general formula (9) (S ₉ ) and the total amount (s _t ) of the isophthalic acids represented by the general formula (10) (s ₁₀ )
Against 50% or less than 30%, s ratio of ₇ and _{s 8 (s 7 / s 8} ) is 2.7 to 4, the ratio of s ₉ and s ₁₀ (s ₉ / s the method according to claim 2 ₁₀₎ of 1.0 to 1.5 _{(although, s 6, s 7, s} 8, s 9 and s ₁₀ is the content indicated by each substance amount ratio .). 4. A molded article comprising the aromatic polyester according to claim 1. 5. The molded article according to claim 4, which contains 400 parts by weight or less of an inorganic filler based on 100 parts by weight of the aromatic polyester. 6. The molded product according to claim 4, which is an electric component or an electronic component. 7. The aromatic polyester 10 according to claim 1,
An aromatic polyester composition containing 400 parts by weight or less of an inorganic filler per 0 parts by weight.