JP6837189B1 - Total aromatic polyester and polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a total aromatic polyester in which sublimates are less generated during a polymerization reaction and foreign substances are reduced, and a polyester resin composition thereof. It is composed of (II), (III) and (IV), and 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) is contained with respect to all the structural units. The amount is 0.5 to 7.5 mol%, the content of the structural unit (III) is 8.5 to 30 mol% with respect to all the structural units, and the structural unit (IV) is with respect to all the structural units. The content of 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 above-mentioned problems with the characteristic total aromatic polyester, wherein the difference between the content of the structural unit (III) and the content of the structural unit (IV) is 0.150 mol% or less. To solve.
[Chemical 1]

[Selection diagram] None

Description

The present invention relates to a total aromatic polyester in which sublimation substances are less generated during a polymerization reaction and foreign substances are reduced, and a polyester resin composition thereof.

Liquid crystal resins such as all-aromatic polyester 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, in the total aromatic polyester of Patent Document 1, a sublimation product is generated during the polymerization reaction, and the sublimation product is deposited and deposited on the inner wall of the polymerization vessel or the like, where it is polycondensed, deteriorated, or carbonized. There was a problem that the substance was mixed into the polymer as a foreign substance.

In addition, the sublimated product generated during the polymerization reaction of the total aromatic polyester is a monomer component, which causes a dissociation of the terminal balance and hinders the increase in molecular weight.

Therefore, it is an object of the present invention to provide a total aromatic polyester in which sublimation substances are less generated during a polymerization reaction and foreign substances are reduced, 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 is the content of the structural unit (III) and the content of the structural unit (IV). We have found that the above problems can be solved by setting the difference to 0.150 mol% or less, and the present inventors have completed the present invention. 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
A total aromatic polyester having a difference between the content of the structural unit (III) and the content of the structural unit (IV) of 0.150 mol% or less.

(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 8.5-30 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 totally aromatic polyester, which comprises gradually raising the temperature from 140 ° C. to 360 ° C. in a stepwise manner.

(5) The all-aromatic polyester according to (4), wherein the temperature rise divided in stages is a temperature rise divided into 140 ° C to 200 ° C, 200 ° C to 270 ° C, and 270 ° C to 360 ° C. Production method.

(6) The method for producing an all-aromatic polyester according to (4) or (5), wherein the rate of temperature rise from 140 ° C. to 200 ° C. is 0.4 ° C./min or more and less than 0.8 ° C./min.

(7) The total aromatic according to any one of (4) to (6), wherein the rate of temperature rise from 200 ° C. to 270 ° C. is 0.8 ° C./min or more and 1.2 ° C./min or less. Method of manufacturing polyester.

(8) The total aromatic according to any one of (4) to (7), wherein the rate of temperature rise from 270 ° C. to 360 ° C. is 0.4 ° C./min or more and 1.2 ° C./min or less. Method of manufacturing polyester.

According to the present invention, it is possible to provide a totally aromatic polyester in which sublimation substances are less generated during a polymerization reaction and foreign substances are reduced, 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 is composed of the following constituent units (I), (II), (III) and (IV) as essential constituents, and contains the constituent unit (I) with respect to 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%, and the content of the constituent unit (III) and the constituent unit (IV). It is a total aromatic polyester having a difference from the content of 0.150 mol% or less.

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%, and further preferably 40 to 63 mol%. , Even 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 further preferably 1.0 to 7.0 mol%. Is 1.2 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. 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. 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 the content and composition of the structural unit (III). Since the difference from the content of the unit (IV) is 0.150 mol% or less, the generation of sublimated substances during the polymerization reaction is small, and foreign substances are reduced. In the total aromatic polyester of the present invention, the difference between the content of the structural unit (III) and the content of the structural unit (IV) is preferably 0.145 mol% or less, preferably 0.140 mol% or less. It is more preferably 0.135 mol% or less, further preferably 0.130 mol% or less, and particularly preferably 0.125 mol% or less. 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, an acylating agent for the polymerized monomer or a monomer having an activated terminal can be used as an acid chloride derivative during the polymerization. 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.

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, and the pressure is changed from a reduced pressure state to a normal pressure state to a predetermined pressure state, 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 polymerizability. Mol%, more preferably 1.2-7.0 mol%, even more preferably 1.5-6.5 mol%, particularly preferably 2.0-6.0 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%.
It is preferable to raise the temperature in steps from 140 ° C. to 360 ° C.

In the method for producing an all-aromatic polyester of the present embodiment, the temperature rise divided in stages is 140 ° C to 200 ° C, 200 ° C to 270 ° C, 270 ° C to 360 ° C. preferable.

In the method for producing an all-aromatic polyester of the present embodiment, the rate of temperature rise from 140 ° C. to 200 ° C. is preferably 0.4 ° C./min or more and less than 0.8 ° C./min, and 0.5 ° C./min. More preferably, it is at least 0.7 ° C./min.

In the method for producing an all-aromatic polyester of the present embodiment, the rate of temperature rise from 200 ° C. to 270 ° C. is preferably 0.8 ° C./min or more and 1.2 ° C./min or less, and 0.9 ° C./min. More preferably, it is at least 1.1 ° C./min.

In the method for producing an all-aromatic polyester of the present embodiment, the rate of temperature rise from 270 ° C. to 360 ° C. is preferably 0.4 ° C./min or more and 1.2 ° C./min or less, and 0.5 ° C./min. More preferably, it is at least 1.1 ° C./min.

In the method for producing a total aromatic polyester of the present embodiment, the amount of 1,4-phenylenedicarboxylic acid used (mol%) and the amount of 4,4'-dihydroxybiphenyl used (mol%) are determined from the viewpoint of increasing the molecular weight. It is preferable that they are equal. It should be noted that the generation of sublimated products during the production of the total aromatic polyester of the present embodiment causes a difference in their contents.

[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)
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. Then, the temperature is further raised under the speed conditions shown in Table 1, and the pressure is reduced to 10 Torr (that is, 1330 Pa) over 20 minutes, and melt polymerization is carried out while distilling acetic acid, excess acetic anhydride, and other low boiling points. went. 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 3 hours under a nitrogen stream to obtain the desired polymer.

[Sublimation quantity]
In the above-mentioned melt polymerization, the amount of sublimated material was measured from the weight change of the reflux column and the upper part of the reactor. The evaluation results are shown in Table 1.

<Evaluation>
The melting point, melt viscosity, amount of terminal groups, and foreign matter were evaluated for the total aromatic polyester of Example 1 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 PerkinElmer), (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 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 of 380 ° C., a shear rate of 1000 / sec, and ISO11443, all aromatic polyester. The melt viscosity of was measured.

[Monomer composition (content)]
The monomer composition 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 was analyzed using gas chromatography (“GC-6890N” manufactured by Azilent Technology Co., Ltd.), and the peak area derived from 1,4-phenylenedicarboxylic acid and the peak derived from 4,4'-dihydroxybiphenyl were analyzed. From the ratio to the area, the difference between the content of the constituent unit derived from 1,4-phenylenedicarboxylic acid and the content of the constituent unit derived from 4,4'-dihydroxybiphenyl was calculated.

[Foreign matter]
All aromatic polyesters were filmed (0.5 g / sheet, film thickness 100 μm) using a high temperature hot press machine (“NP-SNH” manufactured by Toyo Seiki Seisakusho Co., Ltd.). A white backlight was applied to the film, and the number of foreign substances of 0.3 mm or more was confirmed using a loupe. The number of foreign substances was confirmed for 5 films (2.5 g), and the number of foreign substances per unit weight was determined. The case where the number of foreign substances is 0 / g is shown as “◯”, and the case where the number of foreign substances is 1 / g or more is shown as “x”.

<Examples 2 to 4, Comparative Examples 1 to 10>
A polymer was obtained in the same manner as in Example 1 except that the type of raw material monomer, the amount used (mol%), and the rate of temperature rise were as shown in Tables 1 and 2. Further, the same evaluation as in Example 1 was performed (the melt viscosities of Example 4 and Comparative Example 4 were measured at a temperature of 350 ° C.). The evaluation results are shown in Tables 1 and 2.

As shown in Table 2, in Comparative Example 8 in which the rate of temperature rise from 140 ° C. to 200 ° C. is 0.30 ° C./min and Comparative Example 9 in which the temperature rise rate is 0.89 ° C./min, foreign matter is generated. It was. Further, as shown in Tables 1 and 2, Comparative Example 2 in which the rate of temperature rise from 200 ° C. to 270 ° C. is 0.60 ° C./min, and Comparative Example 5, 1.30 ° C. in which the temperature rise rate is 0.69 ° C./min. In Comparative Example 6 at / min, foreign matter was generated. Further, as shown in Tables 1 and 2, Comparative Examples 1 to 4 in which the rate of temperature rise from 270 ° C. to 360 ° C. is 1.50 ° C./min, and Comparative Examples 7 and 1 in which 0.30 ° C./min. Foreign matter was also generated in Comparative Example 10 at 29 ° C./min.

Claims (8)

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
A total aromatic polyester having a difference between the content of the structural unit (III) and the content of the structural unit (IV) of 0.150 mol% or less .
A totally aromatic polyester having a thickness of 100 μm and a film thickness of 0.5 g / sheet, and the number of foreign substances having a thickness of 0.3 mm or more is 0 / g .
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 8.5-30 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 an all-aromatic polyester, which comprises gradually raising the temperature from 140 ° C. to 360 ° C.
A method for producing a total aromatic polyester, wherein the number of foreign substances of 0.3 mm or more when formed into a film with 0.5 g / sheet and a film thickness of 100 μm is 0 / g . The method for producing an all-aromatic polyester according to claim 4, wherein the temperature rise divided in stages is a temperature rise divided into 140 ° C. to 200 ° C., 200 ° C. to 270 ° C., and 270 ° C. to 360 ° C. The method for producing an all-aromatic polyester according to claim 4 or 5, wherein the heating rate from 140 ° C. to 200 ° C. is 0.4 ° C./min or more and less than 0.8 ° C./min. The method for producing an all-aromatic polyester according to any one of claims 4 to 6, wherein the rate of temperature rise from 200 ° C. to 270 ° C. is 0.8 ° C./min or more and 1.2 ° C./min or less. The method for producing an all-aromatic polyester according to any one of claims 4 to 7, wherein the rate of temperature rise from 270 ° C. to 360 ° C. is 0.4 ° C./min or more and 1.2 ° C./min or less.