JPWO2020204125A1 - Total aromatic polyester and polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a total aromatic polyester having very few side reactions during a polymerization reaction and having excellent hue and toughness, and a polyester resin composition thereof. , (II), (III) and (IV), the content of the structural unit (I) is 40 to 75 mol% with respect to all the structural units, and the content of the structural unit (II) with respect to all the structural units. The content is 0.5 to 7.5 mol%, the content of the constituent unit (III) is 8.5 to 30 mol% with respect to all the constituent units, and the constituent unit (IV) with respect to all the constituent units. ) Is 8.5 to 30 mol%, and the total content of the constituent units (I), (II), (III) and (IV) is 100 mol% with respect to all the constituent units. The total aromatic polyester is characterized by having an ester bond or a combination of an ester bond and a ketone bond in the molecule, and the amount of the ketone bond with respect to the total of the ester bond and the ketone bond is 0. The above problem is solved by the total aromatic polyester which is 0000 to 0.0010 mol%. [Chemical formula 1] [Selection diagram] None

Description

The present invention relates to a total aromatic polyester having very few side reactions during a polymerization reaction and having excellent hue and toughness, and a polyester resin composition thereof.

Liquid crystal resins such as all-aromatic polyesters have excellent fluidity, mechanical strength, heat resistance, chemical resistance, electrical properties, and the like in a well-balanced manner, and are therefore suitably widely used as high-performance engineering plastics.

Most of the total aromatic polyesters currently on the market are mainly composed of 4-hydroxybenzoic acid. However, since the melting point of 4-hydroxybenzoic acid homopolymers is higher than the decomposition point, it is necessary to lower the melting point by copolymerizing various components.

The total aromatic polyester using 1,4-phenylenedicarboxylic acid, 1,4-dihydroxybenzene, 4,4'-dihydroxybiphenyl, etc. as the copolymerization component has a high melting point of 350 ° C. or higher and is melted by a general-purpose device. Too expensive to process. In addition, various methods have been tried to lower the melting point of such a high melting point to a temperature that can be processed by a general-purpose melting processing device, but while the melting point can be lowered to some extent, the temperature is high (below the melting point). There is a problem that the mechanical strength cannot be maintained in the vicinity).

In order to solve this problem, a total aromatic polyester having a specific structure containing 6-hydroxy-2-naphthoic acid as a main component has been proposed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-179767

However, the all-aromatic polyester of Patent Document 1 has a problem that a ketone bond is formed by a side reaction during the polymerization reaction, and the product produced by the ketone bond deteriorates the hue of the polymer and lowers the toughness.

An object of the present invention is to provide a total aromatic polyester having very few side reactions during a polymerization reaction and having excellent hue and toughness, and a polyester resin composition thereof.

The present inventors consist of the following constituent units (I), (II), (III) and (IV) as essential constituents, and the content of the constituent unit (I) is 40 to 40 for all the constituent units. It is 75 mol%, the content of the constituent unit (II) is 0.5 to 7.5 mol% with respect to all the constituent units, and the content of the constituent unit (III) with respect to all the constituent units is 8. It is 5 to 30 mol%, and the content of the structural unit (IV) is 8.5 to 30 mol% with respect to all the structural units, and the structural units (I), (II), ( A total aromatic polyester, characterized in that the total content of III) and (IV) is 100 mol%, which has an ester bond or a combination of an ester bond and a ketone bond in the molecule, as described above. The present inventors have found that the above-mentioned problems can be solved by a total aromatic polyester in which the amount of the ketone bond is 0.0000 to 0.0010 mol% with respect to the total of the ester bond and the ketone bond. Has been completed. More specifically, the present invention provides the following.

(1) The essential constituents consist of the following constituent units (I), (II), (III) and (IV).
The content of the structural unit (I) is 40 to 75 mol% with respect to all the structural units.
The content of the structural unit (II) is 0.5 to 7.5 mol% with respect to all the structural units.
The content of the structural unit (III) is 8.5 to 30 mol% with respect to all the structural units.
The content of the structural unit (IV) is 8.5 to 30 mol% with respect to all the structural units.
The total content of the constituent units (I), (II), (III) and (IV) with respect to all the constituent units is 100 mol%.
All aromatic polyester
Total aromatics having an ester bond or a combination of an ester bond and a ketone bond in the molecule, and the amount of the ketone bond relative to the total of the ester bond and the ketone bond is 0.0000 to 0.0010 mol%. polyester.

(2) A polyester resin composition containing the total aromatic polyester according to (1).
(3) A polyester molded product obtained by molding the total aromatic polyester or polyester resin composition according to (1) or (2).
(4) A method for producing an all-aromatic polyester.
It comprises the steps of acylating 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxybiphenyl with fatty acid anhydride and transesterifying with 1,4-phenylenedicarboxylic acid.
For all monomers consisting of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl.
The amount of 6-hydroxy-2-naphthoic acid used is 40-75 mol%,
The amount of 4-hydroxybenzoic acid used is 0.5 to 7.5 mol%,
The amount of 1,4-phenylenedicarboxylic acid used is 8.5 to 30 mol%,
The amount of 4,4'-dihydroxybiphenyl used is 8.5-30 mol%,
The total amount of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl used is 100 mol%.
A method for producing a total aromatic polyester, wherein the final polymerization temperature is 340 ° C. or lower.
(5) The method for producing a totally aromatic polyester according to (4), which comprises using a nitrogen-containing heterocyclic compound as a catalyst.
(6) The method for producing a total aromatic polyester according to (5), wherein the nitrogen-containing heterocyclic compound is 1-methylimidazole.
(7) The method for producing a total aromatic polyester according to (4), which comprises using a potassium compound and / or a trivalent cobalt compound as a catalyst.
(8) The method for producing an all-aromatic polyester according to (7), wherein the potassium compound is potassium acetate.
(9) The method for producing a total aromatic polyester according to (7) or (8), wherein the trivalent cobalt compound is tris (2,4-pentanedionato) cobalt (III).

According to the present invention, it is possible to provide a total aromatic polyester having a very small amount of side reaction during a polymerization reaction and having excellent hue and toughness, and a polyester resin composition thereof.

Hereinafter, one embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications as long as the effects of the present invention are not impaired. In the present invention, "A to B" means "A or more and B or less".

[All aromatic polyester]
The total aromatic polyester according to the present invention comprises the following constituent units (I), (II), (III) and (IV) as essential constituents, and the constituent units (I) are contained in all the constituent units. The amount is 40 to 75 mol%, the content of the constituent unit (II) is 0.5 to 7.5 mol% with respect to all the constituent units, and the content of the constituent unit (III) is contained with respect to all the constituent units. The amount is 8.5 to 30 mol%, and the content of the structural unit (IV) is 8.5 to 30 mol% with respect to all the structural units, and the structural unit (I), ( A total aromatic polyester characterized in that the total content of II), (III) and (IV) is 100 mol%, in which an ester bond or a combination of an ester bond and a ketone bond is incorporated in the molecule. It is a total aromatic polyester having, and the amount of the ketone bond is 0.0000 to 0.0010 mol% with respect to the sum of the ester bond and the ketone bond.

The structural unit (I) is derived from 6-hydroxy-2-naphthoic acid (hereinafter, also referred to as “HNA”). The total aromatic polyester of the present invention contains 40 to 75 mol% of the structural unit (I) with respect to all the structural units. If the content of the structural unit (I) is less than 40 mol%, the melting point is lowered and the heat resistance is insufficient. If the content of the structural unit (I) exceeds 75 mol%, solidification occurs during polymerization and a polymer cannot be obtained. From the viewpoint of heat resistance and polymerizable property, the content of the structural unit (I) is preferably 40 to 70 mol%, more preferably 40 to 65 mol%, still more preferably 40 to 63 mol%, and more. It is more preferably 40 to 62 mol%, and particularly preferably 40 to 60 mol%.

The building block (II) is derived from 4-hydroxybenzoic acid (hereinafter, also referred to as "HBA"). The total aromatic polyester of the present invention contains 0.5 to 7.5 mol% of the structural unit (II) with respect to all the structural units. If the content of the structural unit (II) is less than 0.5 mol%, solidification occurs during polymerization and a polymer cannot be obtained. If the content of the structural unit (II) exceeds 7.5 mol%, the melting point is lowered and the heat resistance is insufficient. From the viewpoint of heat resistance and polymerizable property, the content of the structural unit (II) is preferably 0.5 to 7.0 mol%, more preferably 1.0 to 7.0 mol%, and even more preferably 1. It is .2 to 7.0 mol%, more preferably 1.5 to 6.5 mol%, and particularly preferably 2.0 to 6.0 mol%.

The structural unit (III) is derived from a 1,4-phenylenedicarboxylic acid (hereinafter, also referred to as "TA"). The total aromatic polyester of the present invention contains 8.5 to 30 mol% of the structural unit (III) with respect to all the structural units. If the content of the structural unit (III) is less than 8.5 mol% or more than 30 mol%, at least one of lower melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (III) is preferably 10 to 30 mol%, more preferably 12 to 28 mol%, and further preferably 14 to 28 mol%. It is in mol%, more preferably 15 to 28 mol%, and particularly preferably 17 to 27 mol%.

The structural unit (IV) is derived from 4,4'-dihydroxybiphenyl (hereinafter, also referred to as "BP"). The total aromatic polyester of the present invention contains 8.5 to 30 mol% of structural units (IV) with respect to all structural units. If the content of the structural unit (IV) is less than 8.5 mol% or more than 30 mol%, at least one of low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (IV) is preferably 10 to 30 mol%, more preferably 12 to 28 mol%, and further preferably 14 to 28 mol%. It is in mol%, more preferably 15 to 28 mol%, and particularly preferably 17 to 27 mol%.

As described above, the total aromatic polyester of the present invention contains specific structural units (I) to (IV) in a specific amount with respect to all the structural units, and contains an ester bond or an ester bond and a ketone in the molecule. Since it has a combination with a bond and the amount of the ketone bond is 0.0000 to 0.0010 mol% with respect to the total of the ester bond and the ketone bond, there are very few side reactions during the polymerization reaction, and the hue Is excellent. In the total aromatic polyester of the present invention, the amount of the ketone bond to the total of the ester bond and the ketone bond is preferably 0.0000 to 0.0008 mol%, preferably 0.0000 to 0.0006. It is more preferably mol%, further preferably 0.0000 to 0.0005 mol%, further preferably 0.0000 to 0.0004 mol%, and even more preferably 0.0000 to 0.0002 mol. % Is particularly preferable. In addition, the total aromatic polyester of the present invention contains 100 mol% of the structural units (I) to (IV) in total with respect to all the structural units.

Next, the properties of the total aromatic polyester will be described. The all-aromatic polyester of the present invention exhibits optical anisotropy when melted. Exhibiting optical anisotropy when melted means that the all-aromatic polyester of the present invention is a liquid crystal polymer.

In the present invention, the fact that the all-aromatic polyester is a liquid crystal polymer is an indispensable element for the all-aromatic polyester to have both thermal stability and easy workability. The total aromatic polyester composed of the constituent units (I) to (IV) may not form an anisotropic molten phase depending on the constituent components and the sequence distribution in the polymer, but the polymer of the present invention is used. Limited to all aromatic polyesters that exhibit optical anisotropy when melted.

The nature of melt anisotropy can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. More specifically, the confirmation of melt anisotropy can be carried out by melting a sample placed on a hot stage manufactured by Linkham Co., Ltd. using a polarizing microscope manufactured by Olympus Corporation and observing it at a magnification of 150 times in a nitrogen atmosphere. Liquid crystalline polymers are optically anisotropic and transmit light when inserted between orthogonal polarizers. If the sample is optically anisotropic, polarized light is transmitted even in a molten static liquid state, for example.

Since a nematic liquid crystal polymer causes a significant decrease in viscosity above the melting point, it is generally an index of processability to exhibit liquid crystallinity at a temperature above the melting point. The melting point is preferably as high as possible from the viewpoint of heat resistance, but it is preferably 380 ° C. or lower in consideration of thermal deterioration during melt processing of the polymer and the heating capacity of the molding machine. It is more preferably 260 to 370 ° C, even more preferably 270 to 370 ° C, and particularly preferably 280 to 360 ° C.

The melt viscosity of the total aromatic polyester at a temperature 10 to 40 ° C. higher than the melting point of the total aromatic polyester of the present invention and a shear rate of 1000 / sec is preferably 1000 Pa · s or less, more preferably 4 to 500 Pa. · S, even more preferably 4 to 250 Pa · s, and particularly preferably 5 to 100 Pa · s. When the melt viscosity is within the above range, the total aromatic polyester itself or the composition containing the total aromatic polyester tends to secure fluidity at the time of molding, and the filling pressure becomes excessive. Hateful. In addition, in this specification, the melt viscosity means the melt viscosity measured in accordance with ISO11443.

Next, a method for producing the total aromatic polyester of the present embodiment will be described. The total aromatic polyester of the present embodiment is polymerized by using a direct polymerization method, a transesterification method, or the like. In the polymerization, a melt polymerization method, a solution polymerization method, a slurry polymerization method, a solid phase polymerization method, etc., or a combination of two or more of these is used, and a melt polymerization method or a combination of the melt polymerization method and the solid phase polymerization method is used. Is preferably used.

In the present embodiment, during polymerization, an acylating agent for the polymerized monomer or a monomer having an activated terminal as an acid chloride derivative can be used. Examples of the acylating agent include fatty acid anhydrides such as acetic anhydride.

In the method for producing a total aromatic polyester of the present embodiment, the total amount of fatty acid anhydride used is 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxybiphenyl from the viewpoint of hue. It is preferably less than 1.08 times, more preferably 1.00 to 1.07 times, still more preferably 1.01 to 1.07 times, and 1.01 to 1 times the hydroxyl group equivalent of. It is more preferably .06 times, and particularly preferably 1.02 to 1.06 times. When the amount of the fatty acid anhydride used is within the above range, the amount of the ketone bond tends to be 0.0000 to 0.0010 mol% with respect to the total of the ester bond and the ketone bond.

Various catalysts can be used for these polymerizations, and typical ones are potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris (2). , 4-Pentandionato) Examples include metal salt-based catalysts such as cobalt (III) and organic compound-based catalysts such as 1-methylimidazole and 4-dimethylaminopyridine.

In the reaction, all raw material monomers (6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl), an acylating agent, and a catalyst were used in the same reaction vessel. (One-step method), 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxybiphenyl were acylated with an acylating agent. Later, it can also be reacted with the carboxyl group of 1,4-phenylenedicarboxylic acid (two-stage method).

After the inside of the reaction system reaches a predetermined temperature, melt polymerization is carried out by starting depressurization to a predetermined decompression degree. After the torque of the stirrer reaches a predetermined value, an inert gas is introduced, the pressure is changed from a reduced pressure state to a normal pressure state, and the pressure state is changed to a predetermined value, and the total aromatic polyester is discharged from the reaction system.

The total aromatic polyester produced by the above polymerization method can be further increased in molecular weight by solid-phase polymerization of normal pressure, reduced pressure, or heating in an inert gas.

In the method for producing a total aromatic polyester of the present embodiment, 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxybiphenyl are acylated with a fatty acid anhydride to produce 1,4-phenylene. It is preferable to include a step of transesterifying with a dicarboxylic acid.
For all monomers consisting of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl.
The amount of 6-hydroxy-2-naphthoic acid used is 40 to 75 mol%, preferably 40 to 70 mol%, more preferably 40 to 65 mol%, still more preferably 40 to 63, from the viewpoint of heat resistance and polymerizable property. Mol%, even more preferably 40-62 mol%, particularly preferably 40-60 mol%,
The amount of 4-hydroxybenzoic acid used is 0.5 to 7.5 mol%, preferably 0.5 to 7.0 mol%, more preferably 1.0 to 7.0 from the viewpoint of heat resistance and polymerizable property. Mol%, more preferably 1.2 to 7.0 mol%, even more preferably 1.5 to 6.5 mol%, particularly preferably 2.0 to 6.0 mol%,
The amount of 1,4-phenylenedicarboxylic acid used is 8.5 to 30 mol%, preferably 10 to 30 mol%, more preferably 12 to 28 mol%, and further, from the viewpoint of achieving both a low melting point and heat resistance. Preferably 14-28 mol%, even more preferably 15-28 mol%, particularly preferably 17-27 mol%,
The amount of 4,4'-dihydroxybiphenyl used is 8.5 to 30 mol%, preferably 10 to 30 mol%, more preferably 12 to 28 mol%, and further, from the viewpoint of achieving both a low melting point and heat resistance. Preferably 14-28 mol%, even more preferably 15-28 mol%, particularly preferably 17-27 mol%,
The total amount of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl is preferably 100 mol%.
The final polymerization temperature is preferably 340 ° C. or lower, more preferably 330 ° C. or lower, further preferably 320 ° C. or lower, even more preferably 310 ° C. or lower, and 300 ° C. or lower. Is particularly preferable.

In the method for producing an all-aromatic polyester of the present embodiment, it is preferable to use a nitrogen-containing heterocyclic compound as a catalyst.

In the method for producing a total aromatic polyester of the present embodiment, it is preferable that the nitrogen-containing heterocyclic compound used as a catalyst is 1-methylimidazole.

The method for producing an all-aromatic polyester of the present embodiment preferably uses a potassium compound and / or a trivalent cobalt compound as a catalyst.

In the method for producing an all-aromatic polyester of the present embodiment, it is preferable that the potassium compound used as a catalyst is potassium acetate.

In the method for producing an all-aromatic polyester of the present embodiment, it is preferable that the trivalent cobalt compound used as a catalyst is tris (2,4-pentanedionato) cobalt (III).

The method for producing a total aromatic polyester of the present embodiment is based on the amount of 1,4-phenylenedicarboxylic acid used (mol%) and the amount of 4,4'-dihydroxybiphenyl used (mol%) from the viewpoint of increasing the molecular weight. The difference is preferably 1.00 mol% or less, more preferably 0.75 mol% or less, further preferably 0.50 mol% or less, and more preferably 0.25 mol% or less. Even more preferably, it is particularly preferable that the amount of 1,4-phenylenedicarboxylic acid used (mol%) and the amount of 4,4'-dihydroxybiphenyl used (mol%) are equal.

[Polyester resin composition]
The above-mentioned total aromatic polyester of the present invention can be blended with various fibrous, powdery, plate-like inorganic and organic fillers depending on the purpose of use.

Examples of the inorganic filler blended in the polyester resin composition of the present invention include fibrous, powdery, and plate-like fillers.

Fibrous inorganic fillers include glass fiber, milled glass fiber, asbestos fiber, silica fiber, silica / alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and wollastonite. Examples thereof include silicate fibers such as magnesium sulfate fibers, aluminum borate fibers, and inorganic fibrous substances such as metal fibrous materials such as stainless steel, aluminum, titanium, copper and brass. A particularly typical fibrous filler is glass fiber.

In addition, as powdery granular inorganic fillers, carbon black, graphite, silica, quartz powder, glass beads, glass balloons, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollastonite and the like. Oxides of metals such as acid salts, iron oxide, titanium oxide, zinc oxide, antimony trioxide, alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, sulfates of metals such as calcium sulfate and barium sulfate, and other ferrites. , Carbide, boron nitride, boron nitride, various metal powders and the like.

Examples of the plate-shaped inorganic filler include mica, glass flakes, talc, and various metal foils.

Examples of organic fillers include aromatic polyester fibers, liquid crystal polymer fibers, aromatic polyamides, heat-resistant high-strength synthetic fibers such as polyimide fibers.

These inorganic and organic fillers may be used alone or in combination of two or more. The combined use of the fibrous inorganic filler and the granular or plate-like inorganic filler is a preferable combination in terms of combining mechanical strength, dimensional accuracy, electrical properties, and the like. Particularly preferably, glass fiber is used as the fibrous filler, and mica and talc are used as the plate-shaped filler, and the blending amount thereof is 120 parts by mass or less, preferably 20 to 80 parts by mass with respect to 100 parts by mass of the total aromatic polyester. Is. By combining the glass fiber with mica or talc, the polyester resin composition is particularly remarkable in improving the thermal deformation temperature, mechanical properties and the like.

In using these fillers, a converging agent or a surface treatment agent can be used if necessary.

As described above, the polyester resin composition of the present invention contains the all-aromatic polyester of the present invention as an essential component, and optionally contains an inorganic or organic filler, as long as it does not impair the effects of the present invention. For example, other components may be contained. Here, the other component may be any component, and examples thereof include additives such as other resins, antioxidants, stabilizers, pigments, and crystal nucleating agents.

Further, the method for producing the polyester resin composition of the present invention is not particularly limited, and the polyester resin composition can be prepared by a conventionally known method.

[Polyester molded product]
The polyester molded product of the present invention can be obtained by molding the all-aromatic polyester or polyester resin composition of the present invention. The molding method is not particularly limited, and a general molding method can be adopted. Examples of general molding methods include injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foam molding, rotary molding, gas injection molding, and inflation molding.

The polyester molded product obtained by molding the all-aromatic polyester or the like of the present invention has excellent heat resistance. Further, the polyester molded product obtained by molding the polyester resin composition of the present invention is excellent in heat resistance and contains an inorganic or organic filler as required, so that the mechanical strength and the like are further improved.

Further, since the all-aromatic polyester and polyester resin composition of the present invention are excellent in moldability, they can be processed into various three-dimensional molded products, fibers, films and the like.

Preferred applications of the polyester molded product of the present invention having the above properties include connectors, CPU sockets, relay switch parts, bobbins, actuators, noise reduction filter cases, electronic circuit boards, heating fixing rolls for OA equipment, and the like. Be done.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Example 1>
The following raw material monomers, fatty acid metal salt catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 6-Hydroxy-2-naphthoic acid 0.883 mol (48 mol%) (HNA)
(II) 4-Hydroxybenzoic acid 0.037 mol (2 mol%) (HBA)
(III) 1,4-phenylenedicarboxylic acid 0.46 mol (25 mol%) (TA)
(IV) 4,4'-Dihydroxybiphenyl 0.46 mol (25 mol%) (BP)
1-Methylimidazole catalyst 1100ppm
1.91 mol of acetic anhydride (1.04 times the total hydroxyl equivalent of HNA, HBA, and BP)
After charging the raw materials, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature was further raised under the speed conditions shown in Table 1, and the final polymerization temperature was set as shown in Table 1, and melt polymerization was carried out while distilling acetic acid, excess acetic anhydride, and other low boiling points. After the stirring torque reached a predetermined value, nitrogen was introduced to bring it into a pressurized state, the product was discharged from the lower part of the polymerization vessel, and the mixture was pulverized to obtain a powdery prepolymer. The obtained prepolymer was heat-treated (solid-phase polymerization) at 230 ° C. for 10 hours, 320 ° C. for 30 hours, and 330 ° C. for 30 hours under a nitrogen stream to obtain the desired polymer.

<Evaluation>
The melting point, melt viscosity, ketone bond amount and hue (L value) of the total aromatic polyester of Example 1 were evaluated by the following methods. The evaluation results are shown in Table 1.

[Melting point]
After measuring the heat absorption peak temperature (Tm1) observed when all aromatic polyester is heated from room temperature to 20 ° C./min with a differential scanning calorimeter (DSC, manufactured by Perkin Elmer), (Tm1 + 40). ) After holding at a temperature of ° C for 2 minutes, once cooled to room temperature under a temperature decreasing condition of 20 ° C / min, and then heating again under a heating condition of 20 ° C / min, the temperature of the heat absorption peak observed is measured. did.

[Melting viscosity]
Using a capillograph manufactured by Toyo Seiki Seisakusho Co., Ltd., using an orifice with an inner diameter of 0.5 mm and a length of 30 mm at a temperature 10 to 30 ° C higher than the melting point of all aromatic polyester, at a shear rate of 1000 / sec, ISO11443. The melt viscosity of the total aromatic polyester was measured according to the above.

[Ketone bond amount]
The amount of ketone bond was calculated by the pyrolysis gas chromatography method described in Polymer Degradation and Stability 76 (2002) 85-94. Specifically, using a pyrolysis device (“PY2020iD” manufactured by Frontier Lab Co., Ltd.), all aromatic polyester is heated in the presence of tetramethylammonium hydroxide (TMAH), and gas is pyrolyzed / methylated. Was generated. This gas is analyzed using gas chromatography (“GC-6890N” manufactured by Agilent Technologies, Inc.), and the amount of ketone bond is calculated from the ratio of the peak area derived from the ketone bond to the peak area derived from the ester bond. did.

[Hue (L value)]
The L value of the polymer was measured using a spectral color difference meter (“SE6000” manufactured by Nippon Denshoku Industries Co., Ltd.).

<Examples 2 and 3>
The type of raw material monomer, amount used (mol%), catalyst, heating rate, and final polymerization temperature are as shown in Table 1, and the prepolymer is prepared under a nitrogen stream at 290 ° C. for 10 hours and at 300 ° C. for 10 hours, 310. A polymer was obtained in the same manner as in Example 1 except that heat treatment (solid phase polymerization) was carried out at ° C. for 10 hours and at 320 ° C. for 10 hours. Moreover, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

<Examples 4 and 5>
A polymer was obtained in the same manner as in Example 1 except that the type of raw material monomer, the amount used (mol%), the catalyst, the rate of temperature rise, and the final polymerization temperature were as shown in Table 1. Moreover, the same evaluation as in Example 1 was performed (the melt viscosity of Example 5 was measured at a temperature of 350 ° C.). The evaluation results are shown in Table 1.

<Comparative example 1>
The following raw material monomers, fatty acid metal salt catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 6-Hydroxy-2-naphthoic acid 0.883 mol (48 mol%) (HNA)
(II) 4-Hydroxybenzoic acid 0.037 mol (2 mol%) (HBA)
(III) 1,4-phenylenedicarboxylic acid 0.46 mol (25 mol%) (TA)
(IV) 4,4'-Dihydroxybiphenyl 0.46 mol (25 mol%) (BP)
Potassium acetate catalyst 150ppm
Tris (2,4-pentanedionato) cobalt (III) catalyst 150ppm
1.91 mol of acetic anhydride (1.04 times the total hydroxyl equivalent of HNA, HBA, and BP)
After charging the raw materials, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. After that, the temperature was further raised under the speed conditions shown in Table 1, and the final polymerization temperature was set as shown in Table 1, respectively. From there, the pressure was reduced to 10 Torr (ie, 1330 Pa) over 20 minutes, and melt polymerization was carried out while distilling acetic acid, excess acetic anhydride, and other low boiling points. After the stirring torque reaches a predetermined value, nitrogen is introduced to change the pressure from a reduced pressure state to a pressurized state through normal pressure, and the product is discharged from the lower part of the polymerization vessel and pelletized to obtain a pellet-shaped prepolymer. It was. The obtained prepolymer was heat-treated (solid-phase polymerization) at 300 ° C. for 5 hours under a nitrogen stream to obtain the desired polymer.

<Comparative Examples 2 and 3>
A polymer was obtained in the same manner as in Comparative Example 1 except that the type of raw material monomer, the amount used (mol%), the catalyst, the rate of temperature rise, and the final polymerization temperature were as shown in Table 1. Moreover, the same evaluation as in Example 1 was performed (the melt viscosity of Comparative Example 3 was measured at a temperature of 350 ° C.). The evaluation results are shown in Table 1.

<Example 6>
The total aromatic polyester obtained in Example 1 and the following components were mixed using a twin-screw extruder to obtain a resin composition. The extrusion conditions are as follows. The blending amount of each component is as shown in Table 2.
Fibrous filler Mild fiber: EPH-80M manufactured by Nippon Electric Glass Co., Ltd., fiber diameter 10.5 μm, average fiber length 80 μm (manufacturer's nominal value)
Plate-shaped filler Mica: AB-25S manufactured by Yamaguchi Mica Industry Co., Ltd., average particle size 25 μm

(Extrusion conditions)
The temperature of the cylinder provided at the main feed port was 250 ° C., and the temperature of all other cylinders was 360 ° C. All aromatic polyesters were supplied through the main feed port. The filler was supplied from the side feed port.

<Comparative example 4>
A resin composition was obtained in the same manner as in Example 1 except that the total aromatic polyester obtained in Comparative Example 1 was used.

(Bending test)
The resin composition was injection-molded under the following molding conditions to obtain a molded product having a thickness of 130 mm × 13 mm × 0.8 mm, and the bending strength, flexural modulus, and bending strain were measured according to ASTM D790. The evaluation results are shown in Table 2.

<Molding conditions>
Molding machine: Sumitomo Heavy Industries, SE100DU
Cylinder temperature: 370 ° C
Mold temperature: 80 ° C
Injection speed: 33 mm / sec
Holding pressure: 50 MPa

As shown in Table 2, Example 6 having a ketone bond amount of 0.0001 mol% had a larger bending strain than Comparative Example 4 having a ketone bond amount of 0.12 mol%. This means that the greater the bending strain, the better the toughness, and thus the problem of the present invention is solved.

Claims (9)

The essential constituents consist of the following constituent units (I), (II), (III) and (IV).
The content of the structural unit (I) is 40 to 75 mol% with respect to all the structural units.
The content of the structural unit (II) is 0.5 to 7.5 mol% with respect to all the structural units.
The content of the structural unit (III) is 8.5 to 30 mol% with respect to all the structural units.
The content of the structural unit (IV) is 8.5 to 30 mol% with respect to all the structural units.
The total content of the constituent units (I), (II), (III) and (IV) with respect to all the constituent units is 100 mol%.
All aromatic polyester
Total aromatics having an ester bond or a combination of an ester bond and a ketone bond in the molecule, and the amount of the ketone bond relative to the total of the ester bond and the ketone bond is 0.0000 to 0.0010 mol%. polyester.
The polyester resin composition containing the total aromatic polyester according to claim 1. A polyester molded product obtained by molding the all-aromatic polyester or polyester resin composition according to claim 1 or 2. A method for producing all-aromatic polyester.
It comprises the steps of acylating 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, and 4,4'-dihydroxybiphenyl with fatty acid anhydride and transesterifying with 1,4-phenylenedicarboxylic acid.
For all monomers consisting of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl.
The amount of 6-hydroxy-2-naphthoic acid used is 40-75 mol%,
The amount of 4-hydroxybenzoic acid used is 0.5 to 7.5 mol%,
The amount of 1,4-phenylenedicarboxylic acid used is 8.5 to 30 mol%,
The amount of 4,4'-dihydroxybiphenyl used is 8.5-30 mol%,
The total amount of 6-hydroxy-2-naphthoic acid, 4-hydroxybenzoic acid, 1,4-phenylenedicarboxylic acid, and 4,4'-dihydroxybiphenyl used is 100 mol%.
A method for producing a total aromatic polyester having a final polymerization temperature of 340 ° C. or lower. The method for producing a totally aromatic polyester according to claim 4, wherein a nitrogen-containing heterocyclic compound is used as a catalyst. The method for producing a total aromatic polyester according to claim 5, wherein the nitrogen-containing heterocyclic compound is 1-methylimidazole. The method for producing an all-aromatic polyester according to claim 4, wherein a potassium compound and / or a trivalent cobalt compound is used as a catalyst. The method for producing an all-aromatic polyester according to claim 7, wherein the potassium compound is potassium acetate. The method for producing an all-aromatic polyester according to claim 7 or 8, wherein the trivalent cobalt compound is tris (2,4-pentanedionato) cobalt (III).