JP2002146003A - Liquid crystalline polyester and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystalline polyester which has an excellent impact strength and an excellent insulating property without deteriorating its excellent heat resistance and an excellent tensile strength, and to provide a method for producing the liquid crystalline polyester causing no coloration with excellent productivity. SOLUTION: This method for producing the liquid-crystalline polyester comprises acylating the phenolic hydroxyl groups of an aromatic diol and/or an aromatic hydroxycarboxylic acid with an aliphatic acid anhydride and then subjecting the acylation product to an ester interchange reaction using an aromatic dicarboxylic acid and/or an aromatic hydroxycarboxylic acid, characterized by carrying out the acylation reaction and/or the ester interchange reaction in the presence of a heterocyclic organic basic compound containing two or more nitrogen atoms. The liquid crystalline polyester is obtained by the production method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystalline polyester and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, liquid crystalline polyesters having an aromatic ring skeleton have been used in electric and electronic fields as materials having excellent heat resistance and tensile strength. The liquid crystalline polyester is obtained, for example, by adding acetic anhydride to the phenolic hydroxyl group of an aromatic hydroxycarboxylic acid such as parahydroxybenzoic acid and / or an aromatic diol such as 4,4′-hydroxybiphenyl to acylate the phenolic hydroxyl group. It is produced by a method of transesterifying an acylated product obtained as described above with an aromatic dicarboxylic acid such as terephthalic acid. However, in the above method, the time required for acylation is long, and there is a problem in productivity.In addition, the liquid crystalline polyester having an aromatic skeleton obtained by this method has excellent heat resistance and tensile strength. However, there is a problem that the impact strength is not always sufficient. For this reason, a method has been known in which an organometallic compound such as sodium acetate is added as a catalyst during the acylation reaction to shorten the reaction time (JP-A-11-246654), but the impact strength is not always sufficient, and There is a problem that insulation is poor because ions remain in the resin. Also,
A method of shortening the reaction time by adding a low-boiling organic compound such as pyridine as a catalyst during the acylation reaction (Japanese Patent Laid-Open No.
-1836) is also known, but there are problems that the impact strength is not always sufficient, that the transesterification time is delayed, and that coloring due to side reactions occurs.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystalline polyester which is excellent in impact strength and insulation without impairing excellent heat resistance and tensile strength, and a liquid crystal which is excellent in productivity and does not cause coloring. An object of the present invention is to provide a method for producing a conductive polyester.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to find a liquid crystalline polyester free from the above-mentioned problems and a method for producing the same. As a result, the acylation reaction and / or the transesterification reaction were carried out. It is found that a liquid crystalline polyester obtained by performing in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms has excellent impact strength and insulating properties while maintaining excellent heat resistance and tensile strength. In addition, by performing the acylation reaction and / or transesterification reaction in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms, a liquid crystalline polyester can be efficiently produced without coloration due to side reactions. And found that the present invention was completed.

That is, the present invention provides an acylated product obtained by acylating a phenolic hydroxyl group of an aromatic diol and / or an aromatic hydroxycarboxylic acid with a fatty acid anhydride, and then obtaining the acylated product with an aromatic dicarboxylic acid and / or an aromatic dicarboxylic acid. Alternatively, in the method for producing a liquid crystalline polyester by transesterification with an aromatic hydroxycarboxylic acid, the acylation and / or transesterification is performed in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms. The present invention provides a method for producing a liquid crystalline polyester. Further, the present invention provides an acylated product obtained by acylating a phenolic hydroxyl group of an aromatic diol and / or an aromatic hydroxycarboxylic acid with a fatty acid anhydride, and then adding the acylated product to an aromatic dicarboxylic acid and / or an aromatic dicarboxylic acid. In a process for producing a liquid crystalline polyester by transesterification with a hydroxycarboxylic acid, a liquid crystalline polyester obtained by performing acylation and / or transesterification in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms Is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystalline polyester of the present invention comprises
Forming a melt phase having optical anisotropy, consisting of an aromatic ring skeleton, excellent in heat resistance and tensile strength,
Moreover, it has excellent impact strength. The liquid crystalline polyester of the present invention comprises an acylated product obtained by acylating a phenolic hydroxyl group of an aromatic diol and / or an aromatic hydroxycarboxylic acid with a fatty acid anhydride, and an aromatic dicarboxylic acid and / or an aromatic hydroxycarboxylic acid. Can be obtained by transesterification and condensation polymerization, but can be obtained by performing acylation, transesterification, or acylation and transesterification in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms. It is characteristic.

First, the step of acylating a phenolic hydroxyl group of an aromatic diol and / or an aromatic hydroxycarboxylic acid with a fatty acid anhydride will be described. Examples of the aromatic diol include 4,4′-dihydroxybiphenyl (hereinafter may be abbreviated as (C1)), hydroquinone (hereinafter may be abbreviated as (C2)), resorcinol (hereinafter, (C3) ), Methylhydroquinone, chlorohydroquinone, acetoxyhydroquinone, nitrohydroquinone, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,
6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene (hereinafter sometimes abbreviated as (C4)), 2,
7-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as (C5)), 2,2-bis (4-hydroxy-3,5-
Dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2
-Bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl) propane, bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3,5 -Dimethylphenyl) methane, bis- (4-hydroxy-3,5-dichlorophenyl) methane, bis- (4-hydroxy-3,5
-Dibromophenyl) methane, bis- (4-hydroxy-3-methylphenyl) methane, bis- (4-hydroxy-3-chlorophenyl) methane, 1,1-bis (4-
(Hydroxyphenyl) cyclohexane, bis- (4-hydroxyphenyl) ketone, bis- (4-hydroxy-
3,5-dimethylphenyl) ketone, bis- (4-hydroxy-3,5-dichlorophenyl) ketone, bis-
(4-hydroxyphenyl) sulfide, bis- (4-
Hydroxyphenyl) sulfone (hereinafter sometimes abbreviated as (C6)) and the like. These may be used alone or in combination of two or more. Of these, 4,4 '
-Dihydroxybiphenyl, hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and bis- (4-hydroxyphenyl) sulfone are preferably used because they are easily available.

As the aromatic hydroxycarboxylic acid, for example, parahydroxybenzoic acid (hereinafter sometimes abbreviated as (A1)), metahydroxybenzoic acid, 2-hydroxy-6-naphthoic acid (hereinafter referred to as (A2)) 2-hydroxy-3-naphthoic acid, 1-hydroxy-4-naphthoic acid, 4-hydroxy-4′-carboxydiphenyl ether, 2,6-dichloro-parahydroxybenzoic acid, 2-chloro -Parahydroxybenzoic acid, 2,6-difluoro-parahydroxybenzoic acid, 4
-Hydroxy-4'-biphenylcarboxylic acid and the like. These may be used alone or in combination of two or more. Of these, parahydroxybenzoic acid and 2-hydroxy-6-naphthoic acid are preferably used because they are easily available.

Examples of the fatty acid anhydride include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, and trichloroacetic anhydride. Monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, β-bromopropionic anhydride and the like. It is not particularly limited. These may be used as a mixture of two or more. Acetic anhydride, propionic anhydride, butyric anhydride,
Isobutyric anhydride is preferably used, and acetic anhydride is more preferably used.

The amount of the fatty acid anhydride to the phenolic hydroxyl group of the aromatic diol and / or aromatic hydroxycarboxylic acid is preferably 1.0 to 1.2 times equivalent. Outgas from the molded article is small, and from the viewpoint of the solder blister resistance of the molded article, 1.0 to 1.05 equivalent is more preferable, and 1.03 to 1.05 equivalent is more preferable. Further, from the viewpoint of impact strength, 1.05 to 1.1 times equivalent is preferable. When the amount of the fatty acid anhydride used is less than 1.0 equivalent of the phenolic hydroxyl group, the equilibrium during the acylation reaction shifts to the fatty acid anhydride side, and the unreacted aromatics are polymerized into the polyester. The diol or the aromatic dicarboxylic acid tends to sublime, and the reaction system tends to be clogged. If the amount exceeds 1.2 equivalents, coloring of the obtained liquid crystalline polyester tends to be remarkable.

The acylation reaction is carried out at 130 ° C. to 180 ° C. for 3 hours.
The reaction is preferably performed for 0 to 20 hours,
More preferably, the reaction is performed at 0 ° C. for 1 to 5 hours.

Next, the step of transesterifying the acylated product with an aromatic dicarboxylic acid and / or an aromatic hydroxycarboxylic acid will be described. As the aromatic dicarboxylic acid used in the transesterification, for example, terephthalic acid (hereinafter, may be abbreviated as (B1)), isophthalic acid
(Hereinafter sometimes abbreviated as (B2)), 2,6-naphthalenedicarboxylic acid (hereinafter sometimes abbreviated as (B3))),
1,5-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, methyl terephthalic acid, methyl isophthalic acid, diphenyl ether-4,4′-dicarboxylic acid,
Examples include diphenylsulfone-4,4'-dicarboxylic acid, diphenylketone-4,4'-dicarboxylic acid, and 2,2'-diphenylpropane-4,4'-dicarboxylic acid. These may be used alone or in combination of two or more. Of these, terephthalic acid, isophthalic acid, 2,
6-Naphthalenedicarboxylic acid is preferably used because it is easily available.

As the aromatic hydroxycarboxylic acid used for the transesterification, the same ones as described above can be mentioned.

The amount of the aromatic dicarboxylic acid and / or aromatic hydroxycarboxylic acid used is 0.8 to 1.2 with respect to the acylated product obtained by acylating the aromatic diol and / or aromatic hydroxycarboxylic acid with the fatty acid anhydride. It is preferably a double equivalent.

The transesterification (polycondensation) reaction is carried out at 130 to
It is preferable to carry out the reaction while increasing the temperature at a rate of 0.1 to 50 ° C./min in the range of 400 ° C. Is more preferable.

In the transesterification reaction between the acylated fatty acid ester and the carboxylic acid, in order to shift the equilibrium, the by-produced fatty acid and the unreacted fatty acid anhydride may be evaporated and distilled out of the system. preferable. In addition, by refluxing a part of the distilling fatty acid and returning it to the reactor, it is also possible to condense or reverse sublimate the raw material and the like that evaporate or sublime together with the fatty acid and return it to the reactor. In this case, the precipitated carboxylic acid can be returned to the reactor together with the fatty acid.

The acylation, transesterification, or acylation and transesterification must be performed in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms.
Examples of the heterocyclic organic base compound containing two or more nitrogen atoms include an imidazole compound, a triazole compound, a dipyridylyl compound, a phenanthroline compound,
Diazaphenanthrene compound, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,4-diazabicyclo [2.2.2] octane, 1,8-diazabicyclo [5.4.0] unde -7-cene, N, N-dimethylaminopyridine and the like.

As the imidazole compound, for example,
(1) An imidazole compound represented by the formula: ・ ・ ・ ・ ・ (1) In the formula, R _{1 to} R ₄ are each independently a hydrogen atom and carbon number 1 to
4 alkyl group, hydroxymethyl group, cyano group, cyanoalkyl group having 1 to 4 carbon atoms, cyanoalkoxy group having 1 to 4 carbon atoms, carboxyl group, amino group, 1 to 4 carbon atoms
An aminoalkyl group having 1 to 4 carbon atoms, a phenyl group, a benzyl group, a phenylpropyl group or a formyl group.

Specific examples of the imidazole compound include, for example, imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 1-ethylimidazole, 2-ethylimidazole, 4-ethylimidazole, 1,2-dimethyl Imidazole, 1,4
-Dimethylimidazole, 2,4-dimethylimidazole, 1-methyl-2-ethylimidazole, 1-methyl-4ethylimidazole, 1-ethyl-2-methylimidazole, 1-ethyl-2-ethylimidazole, 1-
Ethyl-2-phenylimidazole, 2-ethyl-4-
Methylimidazole, 2-phenylimidazole, 2-
Undecylimidazole, 2-heptadecylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2
-Methylimidazole, 1-cyanoethyl-2-phenylimidazole, 4-cyanoethyl-2-ethyl-4-
Methylimidazole, 1-aminoethyl-2-methylimidazole, 1- (cyanoethylaminoethyl) -2-
Methylimidazole, N- [2- (2-methyl-1-imidazolyl) ethyl] urea, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-methylimidazole trimellitate, 1-cyanoethyl-2-phenyl Imidazole trimellitate, 1-cyanoethyl-2-ethyl-4-methylimidazole trimellitate, 1-cyanoethyl-2-undecylimidazole trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- ( 1 ')]-Ethyl-S-triazine, 2,4-diamino-6- [2'-undecylimidazolyl (-(1'))
-Ethyl-S-triazine], 2,4-diamino-6-
[2-ethyl-4-methylimidazolyl- (1 ′)]-ethyl-S-triazine, 1-dodecyl-2-methyl-3
-Benzylimidazolium chloride, N, N'-bis (2-methyl-1-imidazolylethyl) urea, N,
N '-(2-methyl-1-imidazolylethyl) adipamide, 2,4-dialkylimidazole-dithiocarboxylic acid, 1,3-dibenzyl-2-methylimidazolium chloride, 2-phenyl-4-methyl-5-hydroxy Methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-cyanoethyl-2-
Phenyl-4,5-bis (cyanoethoxymethyl) imidazole, 2-methylimidazole / isocyanuric acid adduct, 2-phenylimidazole / isocyanuric acid adduct, 2,4-diamino-6- [2′-methylimidazolyl- ( 1 ′)]-Ethyl-S-triazine / isocyanuric acid adduct, 2-alkyl-4-formylimidazole, 2,4-dialkyl-5-formylimidazole, 1-benzyl-2-phenylimidazole, imidazole-4 -Dithiocarboxylic acid, 2-methylimidazole-4-dithiocarboxylic acid, 2-undecylimidazole-4-dithiocarboxylic acid, 2-heptadecylimidazole-4-dithiocarboxylic acid, 2-phenylimidazole-4-dithiocarboxylic acid , 4-methylimidazole-
5-dithiocarboxylic acid, 4-dimethylimidazole-5
-Dithiocarboxylic acid, 2-ethyl-4-methylimidazole-5-dithiocarboxylic acid, 2-undecyl-4-methylimidazole-5-dithiocarboxylic acid, 2-phenyl-4-methylimidazole-5-dithiocarboxylic acid,
1-aminoethyl-2-methylimidazole, 1- (cyanoethylaminoethyl) -2-methylimidazole,
N- (2-methylimidazolyl-1-ethyl) urea;
N, N '-[2-methylimidazolyl (1) -ethyl]
-Adipoyldiamide, 1-aminoethyl-2-ethylimidazole, 4-formylimidazole, 2-methyl-4-formylimidazole, 4-methyl-5-formylimidazole, 2-ethyl-4-methyl- 5-
Formyl imidazole, 2-phenyl-4-methyl-
4-formylimidazole and the like.

As the triazole compound, for example,
1,2,4-triazole, 1,2,3-triazole, benzotriazole and the like can be mentioned. Examples of dipyridylyl compounds include, for example, 2,2′-dipyridylyl,
4,4′-dipyridylyl and the like. Examples of the phenanthroline compound include pyrimidine, purine,
1,7-phenanthroline, 1,10-phenanthroline and the like can be mentioned. Examples of diazaphenanthrene compounds include, for example, pyridazine, triazine, pyrazine,
1,8-diazaphenanthrene and the like can be mentioned.

The heterocyclic organic base compound containing two or more nitrogen atoms is preferably an imidazole compound represented by the formula (1) from the viewpoint of reactivity, and R ₁ represented by the formula (1) from the viewpoint of color tone. Is an alkyl group having 1 to 4 carbon atoms, R ₂
Imidazole compounds are more preferred to R ₄ is a hydrogen atom, further because of easy availability, 1-methylimidazole, 1-ethylimidazole are most preferred.

The amount of the heterocyclic-containing organic base compound containing two or more nitrogen atoms to be added is 0.1 to 100 parts by weight of the total of the aromatic dicarboxylic acid, aromatic diol and aromatic hydroxycarboxylic acid used in the raw material preparation. 005 to 1 part by weight, preferably 0.05 to 0.5 part by weight from the viewpoint of color tone and productivity.
More preferably, it is part by weight. 0.005 added
If the amount is less than 1 part by weight, the effect of improving the impact strength or the like tends to be small. If the amount exceeds 1 part by weight, the control of the reaction tends to be difficult. The heterocyclic organic base compound containing two or more nitrogen atoms may be present at one time during acylation, transesterification, or acylation and transesterification. It may be added immediately before or during the reaction. In particular, when a transesterification reaction is performed by adding a heterocyclic organic base compound containing two or more nitrogen atoms at a temperature of 300 ° C. or higher, the shrinkage of the molded product can be reduced when the molded product is formed.

For the purpose of accelerating the transesterification reaction and increasing the polymerization rate, if necessary, a small amount of a catalyst may be added as long as the object of the present invention is not impaired. Examples of the catalyst to be added include, for example, germanium compounds such as germanium oxide, tin compounds such as stannous oxalate, stannous acetate, dialkyltin oxide, and diaryltin oxide, titanium dioxide, titanium alkoxide, and alkoxytitanium silicon. Titanium compounds such as acids, antimony compounds such as antimony trioxide, metal salts of organic acids such as sodium acetate, potassium acetate, calcium acetate, zinc acetate, ferrous acetate, Lewis acids such as boron trifluoride, aluminum chloride, amines , Amides, and inorganic acids such as hydrochloric acid and sulfuric acid.

The acylation reaction and transesterification (polycondensation) reaction can be performed using, for example, a batch apparatus, a continuous apparatus, or the like.

From the balance of heat resistance and impact resistance, the liquid crystalline polyester of the present invention preferably contains at least 30 mol% of a repeating unit represented by the following formula.

Preferred examples of the liquid crystalline polyester of the present invention obtained by the above production method include those having a repeating structural unit of the following (a) to (f). (A): a structural unit based on the above (A1), a structural unit based on the above (B2), or a structural unit based on a mixture of the above (B1) and (B2), and a structural unit based on the above (C3) combination. (B): In the combination of the structural units of the above (a), a part or all of the structural units based on the above (C3) are replaced with structural units based on the above (C1). (C): In the combination of the structural units of the above (a), part or all of the structural units based on the above (C3) are replaced with structural units based on the above (C2). (D): In the combination of the structural units of the above (a), some or all of the structural units based on the above (C3) are replaced with structural units based on the above (C4). (E): In the combination of the structural units of the above (a), a part or all of the structural units based on the above (C3) are replaced with structural units based on a mixture of the above (C4) and (C5). (F): In the combination of the structural units of the above (a), some or all of the structural units based on the above (A1) are replaced with structural units based on the above (A2).

The weight average molecular weight of the liquid crystalline polyester is preferably from 10,000 to 50,000, but is not particularly limited.

The liquid crystalline polyester of the present invention is excellent in heat resistance and tensile strength and also excellent in impact strength, so that it can be suitably used for high heat resistant materials mainly for electronic and electric parts. .

[0029]

Hereinafter, the present invention will be described with reference to examples.
It goes without saying that the present invention is not limited by the examples.

The properties of the resin, such as tensile strength, impact strength, deflection temperature under load, bending strength, and shrinkage of the molded product, were measured by the following methods. Tensile strength: Measured according to ASTM D638 using an ASTM No. 4 dumbbell. (2) Impact strength A 6.4 × 12.7 × 64 test piece (with no notch) was measured according to ASTM D256. (3) Deflection temperature under load Using a test piece having a length of 127 mm, a width of 12.7 mm and a thickness of 6.4 mm, and conforming to ASTM D648, 18.6 kg
/ Cm ² . Flexural strength (4) Measured in accordance with ASTM-D790 at 13 mm (width) x 64 mm (length) x 3 mm (thickness) with a bending span distance of 40 mm. (5) Shrinkage ratio of molded product 64mm (width) x 64mm (length) x 3mm (thickness), film gate 1mm (thickness), make a molded product, at 23 ℃ molecular flow direction (MD) and perpendicular to it The shrinkage in different directions (TD) was measured. (6) Liquid chromatography (LC) analysis Conditions for LC analysis (area percentage method) are as follows. Sample solution: A 30 mg sample was collected and dissolved in 10 ml of N-methylpyrrolidone. Apparatus: Waters 600E (manufactured by Waters) Detector: Waters 484 (manufactured by Waters) Column: ODS-AM AM-312 (5 μm, 6 mmφ × 15 cm) Column temperature: 40 ° C. Mobile phase: Solution A Methanol (containing 2.5 vol% acetic acid) Solution B Water (containing 2.5 vol% acetic acid) Gradient method: Solution B = 60% → (25 minutes) → 100%
(Hold for 20 minutes) Flow rate: 1.0 ml / min Detection wavelength: UV 254 nm Injection amount 2 μm (7) Solder blister resistance JIS K71131 (1/2) dumbbell x 1.2 mmt H60 at a predetermined temperature
It was immersed in A solder (60% tin, 40% lead) for 60 seconds, and the temperature at which foaming (blister) was observed in the molded product was measured. (8) Generated gas amount 5 g of JIS K71131 (1/2) dumbbell x 0.8 mmt in a glass bottle
After weighing and sealing, the mixture was heated at 120 ° C. for 20 hours, and the total amount of generated gas was measured by a head space gas chromatograph (GC15A / HSS3A manufactured by Shimadzu Corporation).

Example 1 1064 g (7.7 mol) of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl were placed in a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser. 307 g (1.65 mol), terephthalic acid
274.1 g (1.65 mol) and acetic anhydride 1235
g (12.1 mol) were charged. After sufficiently replacing the inside of the reactor with nitrogen gas, the reaction was continued for 15 minutes under a nitrogen gas stream.
The temperature was raised to 0 ° C., and the temperature was maintained and refluxed for 3 hours. Then, after adding 1.1 g of 1-methylimidazole,
While distilling off distilling by-product acetic acid and unreacted acetic anhydride, 2
The temperature was raised to 320 ° C. over a period of 50 minutes, and the point in time at which an increase in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized by a coarse pulverizer, and then heated from room temperature to 250 ° C. over 1 hour under a nitrogen atmosphere, and then heated from 250 ° C. to 335 ° C. over 5 hours to obtain 335 C. for 3 hours, and the polymerization reaction was advanced in a solid layer. When the liquid crystallinity of the obtained resin was measured by a polarizing microscope, it was found that the resin was a liquid crystalline polyester forming a molten phase having optical anisotropy. The obtained resin was mixed with 40% by weight of Asahi Glass's milled glass (REV-8) and mixed, and then a twin-screw extruder (Pike Ikegai Co., Ltd.)
It granulated at 390 degreeC using CM-30). The obtained pellets were injection-molded at a cylinder temperature of 400 ° C. and a mold temperature of 130 ° C. using a PS40E5ASE type injection molding machine manufactured by Nissei Plastic Industry Co., Ltd. to obtain resin characteristics (tensile strength,
(Impact strength, deflection temperature under load) were evaluated.

Examples 2 to 3 and Comparative Examples 1 to 3 Resins were obtained in the same manner as in Example 1 except that the mixing ratio of each raw material and the solid phase polymerization temperature shown in Table 1 were changed, and each measurement was carried out. Table 1 shows the results. In addition, about the obtained resin,
When the liquid crystallinity was measured by a polarizing microscope, it was found that the liquid crystalline polyester formed a molten phase having optical anisotropy in the same manner as in Example 1.

Example 4 In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 911 g (6.6 mol) of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl 409 g (2.2 mol), terephthalic acid 27
4 g (1.65 mol), 91 g of isophthalic acid (0.55 mol)
Mol) and 1235 g (12.1 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained at reflux for 3 hours. Thereafter, 1.1 g of 1-methylimidazole was added, and while distilling off by-produced acetic acid and unreacted acetic anhydride were distilled off, the reaction was carried out for 320 hours over 2 hours and 50 minutes.
The temperature was raised to ° C., and the time when the increase in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, crushed by a coarse crusher, and then heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere,
The temperature was raised to 88 ° C. over 5 hours, kept at 288 ° C. for 3 hours, and the polymerization reaction was advanced in a solid phase. The obtained resin was mixed with 40% by weight of milled glass (EFH-7501) made of Central Glass and mixed, and then a twin-screw extruder (Pike Ikekai Iron Works Co., Ltd.)
It granulated at 340 degreeC using CM-30). The obtained pellets were injection-molded at a cylinder temperature of 350 ° C. and a mold temperature of 130 ° C. using a PS40E5ASE type injection molding machine manufactured by Nissei Plastics Industry Co., Ltd. to obtain resin properties (tensile strength,
(Impact strength, deflection temperature under load) were evaluated.

Comparative Example 4 A resin was obtained in the same manner as in Example 2 except that the solid phase polymerization temperature shown in Table 1 was changed, and each measurement was performed. Table 1 shows the results. In addition, when the liquid crystallinity of the obtained resin was measured by a polarizing microscope, it was found that the resin was a liquid crystalline polyester forming a molten phase having optical anisotropy in the same manner as in Example 2.

[0035]

[Table 1] PHBA: p-hydroxybenzoic acid DHB: 4,4'-dihydroxybiphenyl TP: terephthalic acid IP: isophthalic acid 1MI: 1-methylimidazole

Example 5 A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with p-hydroxybenzoic acid.
835.6 g (6.1 mol), 4,4'-dihydroxybiphenyl 460.9 g (2.48 mol), terephthalic acid 411.2 g (1.6 mol)
5 mol) and 1235 g (12.1 mol) of acetic anhydride.
After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained at reflux for 3 hours. Thereafter, the temperature was raised to 300 ° C. over 2 hours and 30 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride, and 0.3 g of 1-methylimidazole was added.
The temperature was further increased to 320 ° C. over 20 minutes, and the point at which the increase in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized by a coarse pulverizer, and then heated from room temperature to 250 ° C. over 1 hour under a nitrogen atmosphere, and heated from 250 ° C. to 330 ° C. over 5 hours, C. for 3 hours, and the polymerization reaction was advanced in a solid layer. The obtained resin is made of Asahi Glass's milled glass (REV-
After mixing and mixing 8) by 40% by weight, the mixture was granulated at 390 ° C. using a twin-screw extruder (Ikegai Iron Works Co., Ltd. PCM-30). The obtained pellets are converted to PS40 manufactured by Nissei Plastics Industry Co., Ltd.
Using an E5ASE type injection molding machine, cylinder temperature 40
Injection molding was performed at 0 ° C. and a mold temperature of 130 ° C., and the characteristics (bending strength, shrinkage of the molded product) of the resin were evaluated. Bending strength
129MPa, shrinkage of molded product in the direction of molecular flow (MD) is 0
%, Shrinkage of the molded product in the direction perpendicular to the flow (TD) is 1.1%
Met. The anisotropy of shrinkage (TD-MD) was 1.1%.

Comparative Example 5 A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with p-hydroxybenzoic acid.
835.6 g (6.1 mol), 4,4'-dihydroxybiphenyl 460.9 g (2.48 mol), terephthalic acid 411.2 g (1.6 mol)
5 mol) and 1235 g (12.1 mol) of acetic anhydride.
After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained at reflux for 3 hours. Then, 1-methylimidazole was added to 0.3
g, the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride.
The time when the increase in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The resulting solid is cooled to room temperature,
After pulverizing with a coarse pulverizer, the temperature is raised from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere over 5 hours from 250 ° C. to 330 ° C., maintained at 330 ° C. for 3 hours, and polymerized in a solid layer. The reaction proceeded. The obtained resin was mixed with 40% by weight of Asahi Glass's milled glass (REV-8) and mixed, and then 390 using a twin-screw extruder (Ikegai Iron Works Co., Ltd. PCM-30).
Granulated at ℃. The pellets obtained are transferred to Nissei Plastic Industry Co., Ltd.
Injection molding was performed using a PS40E5ASE type injection molding machine manufactured at a cylinder temperature of 400 ° C and a mold temperature of 130 ° C.
The properties (bending strength, shrinkage of the molded product) of the resin were evaluated.
The bending strength was 124 MPa, the shrinkage of the molded article in the direction of flow of the molecule (MD) was 0.1%, and the shrinkage of the molded article in the direction perpendicular to the flow (TD) was 1.4%. The shrinkage anisotropy (TD-MD) is 1.
3%.

Example 6 In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 911 g (6.6 mol) of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl 409 g (2.2 mol), terephthalic acid 27
4 g (1.65 mol), 91 g of isophthalic acid (1.65 mol)
Mol) and 1235 g (12.1 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, 1-
After adding 0.14 g of methylimidazole, the temperature was raised to 150 ° C. over 15 minutes in a nitrogen gas stream, and the temperature was maintained at reflux for 30 minutes. In order to investigate the progress of the acylation reaction, LC analysis was performed, and the acylation reaction rate was calculated from the content ratio of parahydroxybenzoic acid to the acylated parahydroxybenzoic acid. As a result, the reaction rate was 100%
Met. Thereafter, the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride, and the time when a rise in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized with a coarse pulverizer, and then cooled from room temperature to 25% under a nitrogen atmosphere.
The temperature was raised to 0 ° C. over 1 hour, the temperature was raised from 250 ° C. to 276 ° C. over 5 hours, and the temperature was held at 276 ° C. for 3 hours. When the liquid crystallinity was measured, the liquid crystalline polyester was found to be a liquid crystalline polyester forming a molten phase having optical anisotropy.

Example 7 A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 911 g (6.6 mol) of p-hydroxybenzoic acid and 4,4'-dihydroxybiphenyl. 409 g (2.2 mol), terephthalic acid 27
4 g (1.65 mol), 91 g of isophthalic acid (1.65 mol)
Mol) and 1235 g (12.1 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, 1-
After adding 0.29 g of methyl imidazole, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained at reflux for 30 minutes. In order to investigate the progress of the acylation reaction, LC analysis was performed, and the acylation reaction rate was calculated from the content ratio of parahydroxybenzoic acid to the acylated parahydroxybenzoic acid. As a result, the reaction rate was 100%
Met. Thereafter, the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling off by-produced acetic acid and unreacted acetic anhydride, and the time when a rise in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized with a coarse pulverizer, and then cooled from room temperature to 25% under a nitrogen atmosphere.
The temperature was raised to 0 ° C. over 1 hour, the temperature was raised from 250 ° C. to 276 ° C. over 5 hours, and the temperature was held at 276 ° C. for 3 hours. When the liquid crystallinity was measured, the liquid crystalline polyester was found to be a liquid crystalline polyester forming a molten phase having optical anisotropy.

Comparative Example 6 911 g (6.6 mol) of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl were placed in a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser. 409 g (2.2 mol), terephthalic acid 27
4 g (1.65 mol), 91 g of isophthalic acid (1.65 mol)
Mol) and 1235 g (12.1 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas flow, and the temperature was maintained at reflux for 30 minutes. In order to examine the progress of the acylation reaction, LC analysis was performed to determine the content ratio of parahydroxybenzoic acid and the acylated parahydroxybenzoic acid.
The acylation reaction rate was calculated. As a result, the acylation reaction rate was 93%.

Example 8 A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 911 g (6.6 mol) of p-hydroxybenzoic acid and 4,4'-dihydroxybiphenyl. 409 g (2.2 mol), terephthalic acid 27
4 g (1.65 mol), 91 g of isophthalic acid (0.55 mol)
Mol) and 1123 g (11.55 mol) of acetic anhydride. After sufficiently replacing the inside of the reactor with nitrogen gas, 1-
After adding 0.3 g of methylimidazole, the temperature was raised to 150 ° C. over 15 minutes under a nitrogen gas stream, and the temperature was maintained at reflux for 60 minutes. Acetic acid by-product distilled off thereafter,
3 hours over 2 hours and 50 minutes while distilling off unreacted acetic anhydride.
The temperature was raised to 20 ° C., and the point at which the increase in torque was recognized was regarded as the end of the reaction, and the contents were taken out. The obtained solid content was cooled to room temperature, pulverized by a coarse pulverizer, and then under a nitrogen atmosphere,
The temperature was raised from room temperature to 250 ° C. over 1 hour, then from 250 ° C. to 281 ° C. over 5 hours, kept at 281 ° C. for 3 hours, and the polymerization reaction proceeded in a solid phase. The obtained resin was mixed with milled glass (EFH-7501) made of Central Glass 4
After mixing and mixing so as to be 0% by weight, the mixture was granulated at 340 ° C. using a twin-screw extruder (PCM-30, Ikegai Iron Works Co., Ltd.). The obtained pellets are PS4 manufactured by Nissei Resin Industry Co., Ltd.
Using a 0E5ASE type injection molding machine, cylinder temperature 3
Injection molding was performed at 50 ° C. and a mold temperature of 130 ° C., and the properties of the resin (solder blister resistance, generated gas amount) were evaluated.
Table 2 shows the results.

Example 9 The procedure of Example 1 was repeated except that 1123 g (11 mol) of acetic anhydride was charged. Table 2 shows the results.

Comparative Example 7 Example 2 was repeated except that N-methylimidazole was not used.
The same was done. Table 2 shows the results.

[0044]

[Table 2] PHBA: p-hydroxybenzoic acid DHB: 4,4'-dihydroxybiphenyl TP: terephthalic acid IP: isophthalic acid 1MI: 1-methylimidazole

[0045]

The liquid crystalline polyester of the present invention has excellent heat resistance and tensile strength, and has particularly excellent impact strength and insulating properties. Very useful as a heat resistant material. Further, according to the present invention, the liquid crystalline polyester can be efficiently produced without coloring due to a side reaction.

Continued on the front page F-term (reference) 4J029 AA01 AA02 AA03 AA04 AA05 AA06 AB04 AC02 AE03 AE04 BB03 BB05 BB09 BB11 BB12 BB13 BC03 BC05 BC07 BC09 BG06 BG08 BG15 CB05 CB06 CB07 CB11 CB11 EC03 CB12 CC03 CE03 HB01 JC26 JF03 JF04 JF14 JF18 JF32 JF36 JF37 JF47 JF56 KC04 KE02

Claims (5)

[Claims] A phenolic hydroxyl group of an aromatic diol and / or an aromatic hydroxycarboxylic acid is acylated with a fatty acid anhydride to obtain an acylated product, and then the acylated product is combined with an aromatic dicarboxylic acid and / or an aromatic hydroxycarboxylic acid. A process for producing a liquid crystalline polyester by transesterification with a carboxylic acid, wherein the acylation and / or transesterification is carried out in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms. Manufacturing method. 2. The method according to claim 1, wherein a heterocyclic organic base compound containing two or more nitrogen atoms is added at 300 ° C. or more to carry out transesterification. 3. The method according to claim 1, wherein the heterocyclic organic base compound containing two or more nitrogen atoms is an imidazole compound represented by the formula (1). (Wherein, R _{1 to} R ₄ each independently represent a hydrogen atom,
Alkyl group, hydroxymethyl group, cyano group, cyanoalkyl group having 1 to 4 carbon atoms, cyanoalkoxy group having 1 to 4 carbon atoms, carboxyl group, amino group, 1 to 4 carbon atoms
4 represents an aminoalkyl group, an aminoalkoxy group having 1 to 4 carbon atoms, a phenyl group, a benzyl group, a phenylpropyl group or a formyl group. ) 4. An aromatic diol is 4,4-dihydroxybiphenyl, an aromatic hydroxycarboxylic acid is parahydroxybenzoic acid, and an aromatic dicarboxylic acid is terephthalic acid, isophthalic acid or terephthalic acid and isophthalic acid. The production method according to any one of 1 to 3. 5. A liquid crystalline polyester obtained by the production method according to claim 1.