TW201840638A - Wholly aromatic polyester and polyester resin composition - Google Patents

Abstract

To provide: a wholly aromatic polyester having high thermal stability and good hydrolysis resistance; and a polyester resin composition. The problem is solved by using a wholly aromatic polyester composed of 60-85 mol% of 6-hydroxy-2-naphthoic acid, 12-40 mol% of 4-hydroxybenzoic acid, and 0.1-3 mol% of 1,4-phenylenedicarboxylic acid or 4,4'-dihydroxybiphenyl.

Description

   Fully aromatic polyester and polyester resin composition   

The present invention relates to a wholly aromatic polyester having high thermal stability and good hydrolysis resistance, and the polyester resin composition.

The liquid crystalline polymer represented by the liquid crystalline polyester resin has good balance and excellent fluidity, mechanical strength, heat resistance, chemical resistance, and electrical properties, so it can be widely used as a high-functional engineering plastic. .

Patent Document 1 discloses an improved manufacturing method of a thermally stable thermotropic liquid crystalline polyester having a predetermined chain length. In this document, the liquid crystal polyester contains a small amount of 1,4-phenylene dicarboxylic acid to improve thermal stability. However, the thermal stability of the liquid crystalline polyester is not necessarily sufficient.

Patent Document 2 also discloses a method for producing a thermally stable thermotropic liquid crystalline polyester having a predetermined chain length. In this document, the liquid crystal polyester contains a small amount of 2,6-dihydroxynaphthalene or 4,4'-dihydroxybiphenyl to improve thermal stability. However, the thermal stability of the liquid crystalline polyester is not necessarily sufficient.

Patent Document 3 discloses a liquid crystal aromatic polyester for an insulating material and a resin composition thereof. In this document, a low dielectric tangent is achieved by containing a large amount of 6-hydroxy-2-naphthoic acid in the liquid crystalline aromatic polyester. However, the liquid crystalline aromatic polyester is only a combination of highly reactive hydroxycarboxylic acids, and has the problems of poor thermal stability and a large amount of decomposition gas.

In addition, these liquid crystalline polyesters may not be sufficiently resistant to hydrolysis. For polyester molded products obtained by molding a polyester resin composition under a hot and humid environment such as high temperature and humidity, hydrolysis is promoted, and The problem of significant reduction in heat resistance and mechanical strength.

[Prior technical literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 60-040127

Patent Document 2: Japanese Patent Application Laid-Open No. 60-245631

Patent Document 3: Japanese Patent Application Laid-Open No. 2004-250620

The present invention has been made in order to solve the above problems, and has as its object to provide a wholly aromatic polyester having high thermal stability and good hydrolysis resistance, and the polyester resin composition.

As a result of intensive research, the inventors found that by using 60-85 mole% of 6-hydroxy-2-naphthoic acid, 12-40 mole% of 4-hydroxybenzoic acid, and 1,4-phenylene di A fully aromatic polyester composed of carboxylic acid or 4,4'-dihydroxybiphenyl at 0.1 to 3 mole% can solve the above problems, and the present inventors have completed the present invention. More specifically, the present invention provides the following.

(1) A wholly aromatic polyester with the following constituent units (I), (II), and (III) or (IV) as a necessary constituent component combination, and the content of the constituent unit (I) to the total constituent units is 60 to 85 mol%, the content of constituent unit (II) is 12 ~ 40 mol%, and the content of constituent unit (III) or (IV) is 0.1 ~ 3 mol%, (I) , (II), and (III) or (IV) total content is 100 mol% for all constituent units: [化 1]

(2) The wholly aromatic polyester according to (1), which has a melt viscosity of 1000 Pa · s or less at a temperature 10 to 30 ° C higher than the melting point of the wholly aromatic polyester.

(3) The wholly aromatic polyester according to (1) or (2), which has a melt viscosity of 3 to 500 Pa · s at a temperature 10 to 30 ° C higher than the melting point of the wholly aromatic polyester.

(4) The wholly aromatic polyester according to any one of (1) to (3), which has a melting point of 380 ° C or lower.

(5) The wholly aromatic polyester according to any one of (1) to (4), having a melting point of 250 to 370 ° C.

(6) The wholly aromatic polyester according to any one of (1) to (5), wherein the heat of crystallization is 2.5 J / g or more.

(7) The wholly aromatic polyester according to any one of (1) to (6), wherein the value of [melting point-crystallization temperature] is 20 ° C or higher.

(8) A polyester resin composition containing the wholly aromatic polyester according to any one of (1) to (7).

(9) A polyester molded article obtained by molding the wholly aromatic polyester or polyester resin composition according to any one of (1) to (8).

According to the present invention, a fully aromatic polyester having high thermal stability and good hydrolysis resistance, and the polyester resin composition can be provided.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be appropriately modified and implemented within a range that does not inhibit the effects of the present invention.

[Fully aromatic polyester]

Regarding the wholly aromatic polyester of the present invention, the following constituent units (I), (II), and (III) or (IV) are used as a necessary constituent component combination, and the content of the constituent unit (I) to the total constituent units is 60 to 85 mol%, the content of constituent unit (II) is 12 ~ 40 mol%, and the content of constituent unit (III) or (IV) is 0.1 ~ 3 mol%, (I) , (II), and (III) or (IV) total content is 100 mole% for all constituent units

The constituent unit (I) is derived from 6-hydroxy-2-naphthoic acid (hereinafter also referred to as "HNA"). The wholly aromatic polyester of the present invention contains 60 to 85 mol% of the constituent units (I) in the total constituent units. If the content of the constituent unit (I) is less than 60 mol%, the melting point will decrease and the heat resistance will be insufficient. When the content of the constituent unit (I) exceeds 85 mol%, curing occurs during polymerization, and a polymer cannot be obtained. The content of the constituent unit (I) is preferably 63 to 85 mol%, more preferably 63 to 83 mol%, further preferably 65 to 83 mol%, and even more preferably 65 to 80 mol%. 68 ~ 80 mole% is the best.

The constituent unit (II) is derived from 4-hydroxybenzoic acid (hereinafter also referred to as "HBA". The wholly aromatic polyester of the present invention contains 12 to 40 mol% of the constituent units (II) for the entire constituent unit. Composition When the content of the unit (II) is less than 12 mol%, the polymer will solidify in the polymerization container and cannot be discharged during the manufacturing process. If the content of the unit (II) exceeds 40 mol%, the melting point will decrease. However, the heat resistance is insufficient. From the viewpoint of melting point and polymerizability, the content of the constituent unit (II) is preferably 15 to 40 mole%, more preferably 15 to 35 mole%, and further 18 to 35 mole%. Preferably, it is more preferably 18 to 30 mole%, and most preferably 20 to 30 mole%.

The constituent unit (III) is composed of 1,4-phenylene dicarboxylic acid. (Hereinafter also referred to as "TA"). The constituent unit (IV) is derived from 4,4'-dihydroxybiphenyl (hereinafter also referred to as "BP"). The wholly aromatic polyester of the present invention contains 0.1 to 3 mol% of the constituting unit (III) or the constituting unit (IV) for the entire constituting unit. If the content of the constituent unit (III) or the constituent unit (IV) is less than 0.1 mol%, the thermal stability will decrease. When the content of the constituent unit (III) or the constituent unit (IV) exceeds 3 mol%, the molecular weight (melt viscosity) cannot be increased. From the viewpoint of thermal stability and molecular weight, the content of the constituent unit (III) or the constituent unit (IV) is preferably 0.2 to 2.5 mole%, more preferably 0.2 to 2 mole%, and further 0.3 to 2 mole%. Preferably, 0.3 to 1.5 mol% is more preferred, and 0.4 to 1.5 mol% is most preferred.

As described above, since the wholly aromatic polyester of the present invention contains specific constituent units (I) to (IV) in a specific amount for all constituent units, it generates less gas, has high thermal stability, and is resistant to hydrolysis. Sex is good. In addition, the wholly aromatic polyester of the present invention contains 100 mol% of constituent units (I) to (IV) in total for all constituent units.

Next, the properties of the wholly aromatic polyester will be described. The wholly aromatic polyester of the present invention exhibits optical anisotropy when melted. It shows optical anisotropy at the time of melting, and shows the wholly aromatic polyester-based liquid crystalline polymer of the present invention.

In the present invention, the wholly aromatic polyester-based liquid crystal polymer and the wholly aromatic polyester have both indispensable elements of thermal stability and ease of processing. The wholly aromatic polyesters composed of the above-mentioned constituent units (I) to (IV) also have polymers that do not form an anisotropic melt phase depending on the constituent components and the sequence distribution in the polymer, but the polymer of the present invention is only Limited to fully aromatic polyesters that exhibit optical anisotropy when melted.

The properties of the melt anisotropy can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. Specifically, the melting anisotropy was confirmed by using a polarizing microscope manufactured by Olympus Corporation, melting a sample placed on a heating stage manufactured by Linkam Corporation, and observing and implementing at a magnification of 150 times in a nitrogen atmosphere. Liquid crystal polymers are optically anisotropic and can penetrate light when inserted between orthogonal polarizers. The sample is optically anisotropic, and, for example, polarized light can be transmitted even in a molten liquid state.

Since a nematic liquid crystalline polymer has a significant decrease in viscosity above the melting point, it generally shows liquid crystallinity at a temperature above the melting point and becomes an index of processability. From the viewpoint of heat resistance, the higher the melting point, the better. However, in consideration of thermal deterioration during the melt processing of the polymer and the heating ability of the molding machine, a temperature of 380 ° C. or lower is a preferred standard. Furthermore, the melting point is more preferably 250 to 370 ° C, further preferably 270 to 370 ° C, even more preferably 270 to 350 ° C, and most preferably 290 to 350 ° C.

The melting viscosity of the wholly aromatic polyester at a temperature higher than the melting point of the wholly aromatic polyester of the present invention by 10 to 30 ° C. and at a shear rate of 1000 / second is preferably 1000 Pa · s or less, and 3 to 500 Pa ‧S is better, further preferably 3 ~ 250Pa‧s. When the said melt viscosity is in the said range, the said wholly aromatic polyester itself, or the composition containing the said fully aromatic polyester, when it shape | molds, it is easy to ensure fluidity | liquidity, and it is not easy to make filling pressure excessive. In addition, in this specification, melt viscosity means the melt viscosity measured according to ISO11443.

The heat of crystallization of the wholly aromatic polyester of the present invention is preferably 2.5 J / g or more, and more preferably 2.5 to 4.4 J / g. When the heat of crystallization showing the crystallization state of the polymer obtained by differential calorimetry measurement is less than 2.5 J / g, the crystallinity is lowered and the hydrolysis resistance is deteriorated. In addition, if the heat of crystallization exceeds 4.4 J / g, the toughness becomes low and unfavorable.

The heat of crystallization refers to the measurement of differential calorimetry. When the polymer is measured from room temperature at a temperature rising condition of 20 ° C / min, the endothermic peak temperature (Tm1) is observed and then (Tm1 + 40) After holding the temperature at 2 ° C for 2 minutes, the heat value of the heat generation peak obtained from the peak of the heat generation peak temperature observed during the measurement at a temperature reduction condition of 20 ° C / min.

In addition, in the wholly aromatic polyester of the present invention, the value of [melting point-crystallization temperature] minus the crystallization temperature value from the melting point is preferably 20 ° C or more, and more preferably 30 to 90 ° C. When the value of [melting point-crystallization temperature] is within the above range, the wholly aromatic polyester itself or the composition containing the wholly aromatic polyester is easy to ensure fluidity during molding, and it is not easy to change the filling pressure. Too much.

Next, the manufacturing method of the wholly aromatic polyester of this invention is demonstrated. The wholly aromatic polyester of the present invention is polymerized by a direct polymerization method or a transesterification method. In the polymerization, a melt polymerization method, a solution polymerization method, a slurry polymerization method, a solid phase polymerization method, or the like, or a combination of two or more of these can be used, and the melt polymerization method, or the melt polymerization method and the solid phase polymerization can be suitably used. Combination of methods.

In the present invention, during polymerization, a halogenating agent for a polymerized monomer or a terminally active monomer can be used as a derivative of an acid chloride. Examples of the hydrating agent include fatty acid anhydrides such as acetic anhydride.

Various catalysts can be used for such polymerization. Representative examples include potassium acetate, magnesium acetate, tin acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris (2,4-pentane). Diacid) metal salt-based catalysts such as cobalt (III), organic compound-based catalysts such as N-methylimidazole and 4-dimethylaminopyridine. The amount of catalyst used is generally based on the total mass of the monomer, about 0.001 to 1% by mass, and particularly preferably 0.003 to 0.2% by mass.

[Polyester resin composition]

The above-mentioned wholly aromatic polyester of the present invention can be formulated with various fibrous, powdery, granular, and plate-shaped inorganic and organic fillers according to the purpose of use.

The inorganic filler to be blended in the polyester resin composition of the present invention is fibrous, granular, or plate-like.

Fibrous inorganic fillers include glass fiber, ground glass fiber, asbestos fiber, silica fiber, silica dioxide, alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron Fibers, potassium titanate fibers, silicate fibers such as wollastonite, magnesium sulfate fibers, aluminum borate fibers, and fibrous materials such as stainless steel, aluminum, titanium, copper, brass and other metal fibrous materials substance. In particular, a representative fibrous filler-based glass fiber.

In addition, powdery and granular inorganic fillers can be carbon black, graphite, silicon dioxide, quartz powder, glass beads, glass balloons, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, silicon Silicates such as limestone, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, aluminum oxide, etc., metal carbonates such as calcium carbonate, magnesium carbonate, etc., such as calcium sulfate, barium sulfate, etc. Metal sulfates, other ferrites, silicon carbide, silicon nitride, boron nitride, various metal powders, etc.

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

The polyester resin composition formulated in the present invention shows examples of organic fillers, and includes heat-resistant high-strength synthesis of aromatic polyester fibers, liquid crystalline polymer fibers, aromatic polyimide, and polyimide fibers. fiber.

These inorganic and organic fillers may be used alone or in combination of two or more. The combination of the fibrous inorganic filler and the granular or plate-shaped inorganic filler is a good combination in terms of both mechanical strength, dimensional accuracy, and electrical properties. Particularly preferred is glass fiber as the fibrous filler, and mica and talc as the plate-shaped filler. The blending amount is 120 mass parts or less for the 100% by mass of the wholly aromatic polyester, and preferably 20 to 80 mass parts. By combining glass fiber with mica or talc, the polyester resin composition is particularly improved in thermal deformation temperature and mechanical properties.

When using these fillers, an astringent or surface treatment agent can be used as required.

As described above, the polyester resin composition of the present invention contains the wholly aromatic polyester of the present invention as an essential component and contains an inorganic or organic filler as necessary, but it may be within a range that does not impair the effects of the present invention. Contains other ingredients. Here, the other component may be any component, and examples thereof include additives such as other resins, antioxidants, stabilizers, pigments, and crystal nucleating agents.

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 molding]

The polyester molded article of the present invention is formed by molding the wholly aromatic polyester or polyester resin composition of the present invention. The molding method is not particularly limited, and a general molding method can be used. Examples of general molding methods include methods such as injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foaming molding, rotation molding, gas injection molding, and inflation molding.

A polyester molded product obtained by molding the wholly aromatic polyester of the present invention is excellent in heat resistance. In addition, a polyester molded article formed by molding the wholly aromatic polyester or the like of the present invention is excellent in heat resistance, and can contain an inorganic or organic filler as needed, which can further improve mechanical strength and the like.

In addition, the wholly aromatic polyester and polyester resin composition of the present invention can be processed into various three-dimensional molded products, fibers, films, and the like due to their excellent moldability.

The preferred use of the polyester molded article of the present invention having the properties described above may include connectors, CPU sockets, relay switch parts, bobbins, actuators, noise reduction filter boxes, electronic circuit boards, or heating and fixing of OA equipment. Rollers, etc.

Examples

The following examples illustrate the present invention more specifically, but the present invention should not be limited to these examples.

<Example 1>

In a polymerization vessel having a stirrer, a reflux column, a monomer input port, a nitrogen introduction port, and a pressure reducing / outflow line, the following raw material monomers, fatty acid metal salt catalysts were placed, an amylating agent, and nitrogen replacement was started.

(I) 6-hydroxy-2-naphthoic acid 1.44 moles (76 mole%) (HNA)

(II) 4-hydroxybenzoic acid 0.44 mole (23.3 mole%) (HBA)

(III) 0.1 mol terephthalic acid (0.7 mol%) (TA)

Potassium acetate catalyst 22.5mg

196 g of acetic anhydride (1.02 times the amount of total hydroxyl groups of HNA and HBA)

After putting in the raw materials, the temperature of the reaction system was raised to 140 ° C, and the reaction was carried out at 140 ° C for 2 hours. Thereafter, the temperature was further increased to 340 ° C. for 4.1 hours, and the pressure was reduced to 10 Torr (ie, 1330 Pa) for 15 minutes, and polycondensation was performed while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced, and the pressure was changed from a reduced pressure state to a pressure state through normal pressure, and the polymer was discharged from the lower part of the polymerization vessel.

<Evaluation>

The wholly aromatic polyester of Example 1 was evaluated for melting point, crystallization temperature, heat of crystallization, melt viscosity, thermal stability, and hydrolysis resistance by the following methods. The evaluation results are shown in Table 1.

[Melting point]

When using a differential scanning calorimeter (DSC, manufactured by PerkinElmer) to measure the wholly aromatic polyester from room temperature at a temperature rising condition of 20 ° C./min, the endothermic peak temperature (Tm1) was observed, followed by After the temperature of (Tm1 + 40) ° C was maintained for 2 minutes, the temperature of the endothermic peak observed during the measurement was measured again under the temperature-raising condition of 20 ° C / min.

[Crystallization temperature]

When using a differential scanning calorimeter (DSC, manufactured by PerkinElmer) to measure the wholly aromatic polyester from room temperature at a temperature rising condition of 20 ° C / min, the endothermic peak temperature (Tm1) was observed and After maintaining the temperature at (Tm1 + 40) ° C for 2 minutes, the exothermic peak temperature observed during the measurement was measured under a temperature-reducing condition of 20 ° C / min.

[Heat of crystallization]

When using a differential scanning calorimeter (DSC, manufactured by PerkinElmer) to measure the wholly aromatic polyester from room temperature at a temperature rising condition of 20 ° C./min, the endothermic peak temperature (Tm1) was observed, followed by After maintaining the temperature at (Tm1 + 40) ° C for 2 minutes, the calorific value of the calorific peak obtained by measuring the calorific peak temperature observed during the measurement under the temperature-reducing condition of 20 ° C / min.

[Melting viscosity]

Using a capillary rheometer manufactured by Toyo Precision Machinery Co., Ltd., using a temperature of 10-30 ° C higher than the melting point of wholly aromatic polyester, using an orifice with an inner diameter of 0.5mm and a length of 30mm, at a shear rate of 1000 / sec According to ISO11443, the melt viscosity of fully aromatic polyester is measured.

[Thermal stability]

Using a differential thermogravimetric simultaneous measurement device (TG / DTA, manufactured by SII Co., Ltd.), 10 mg of a wholly aromatic polyester was measured under a nitrogen stream, and the weight loss was measured at 370 ° C for 30 minutes as the amount of generated gas. In addition, if the amount of generated gas was less than 15,000 ppm, it was determined to be good.

[Hydrolysis resistance]

The fully aromatic polyester was subjected to a pressure cooker test at 121 ° C., a humidity of 100%, and a pressure of 2 atmospheres for 100 hours. The melt viscosity of the wholly aromatic polyester was measured, and the retention rate of the initial value was determined. In addition, when the retention rate of the initial value was 90% or more, it was judged to be good.

<Example 2>

A polymer was obtained in the same manner as in Example 1 except that the type of the raw material monomer and the insertion ratio (mol%) were as shown in Table 1. The obtained polymer was heated from room temperature to 290 ° C. for 20 minutes under a nitrogen atmosphere, and kept for 3 hours, and then allowed to cool to obtain a polymer again. The same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 3>

In a polymerization vessel having a stirrer, a reflux column, a monomer input port, a nitrogen introduction port, and a pressure reducing / outflow line, the following raw material monomers, fatty acid metal salt catalysts were placed, an amylating agent, and nitrogen replacement was started.

(I) 6-hydroxy-2-naphthoic acid 1.51 mole (81 mole%) (HNA)

(II) 4-hydroxybenzoic acid 0.34 mole (18 mole%) (HBA)

(IV) 4,4'-dihydroxybiphenyl 0.02 mole (1 mole%) (BP)

Potassium acetate catalyst 22.5mg

196 g of acetic anhydride (1.02 times the amount of total hydroxyl groups of HNA, HBA, and BP)

After putting in the raw materials, the temperature of the reaction system was raised to 140 ° C, and the reaction was carried out at 140 ° C for 2 hours. Thereafter, the temperature was raised to 370 ° C. for 4.7 hours, and the pressure was reduced to 10 Torr (that is, 1330 Pa) for 15 minutes, and polycondensation was performed while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced, and the pressure was changed from a reduced pressure state to a pressure state through normal pressure, and the polymer was discharged from the lower part of the polymerization vessel. The same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Examples 4 to 8, Comparative Examples 1 to 8>

The polymer was obtained in the same manner as in Example 1 except that the types of raw material monomers and the insertion ratio (mol%) were as shown in Tables 1 and 2. The same evaluation as in Example 1 was performed. The results are shown in Tables 1 and 2. In addition, in Comparative Example 4, the polymer was cured in the polymerization container at the time of manufacture, and the polymer could not be discharged.

Claims (9)

A fully aromatic polyester with the following constituent units (I), (II), and (III) or (IV) as a necessary constituent component combination: the content of constituent unit (I) to the total constituent units is 60 to 85 mol %, The content of the constituent unit (II) to the total constituent unit is 12 to 40 mol%, and the content of the constituent unit (III or IV) to the total constituent unit is 0.1 to 3 mol%, (I), (II), And the total content of (III) or (IV) is 100 mole% to the total constituent units:     The fully aromatic polyester described in item 1 of the scope of patent application has a melt viscosity of 1000 Pa · s or less at a temperature 10 to 30 ° C higher than the melting point of the wholly aromatic polyester.         For example, the fully aromatic polyester described in the scope of application patents 1 or 2 has a melt viscosity of 3 to 500 Pa · s at a temperature 10 to 30 ° C higher than the melting point of the wholly aromatic polyester.         The fully aromatic polyester according to any one of claims 1 to 3, which has a melting point of 380 ° C or lower.         The fully aromatic polyester according to any one of claims 1 to 4, which has a melting point of 250 to 370 ° C.         The fully aromatic polyester according to any one of claims 1 to 5, the heat of crystallization is 2.5 J / g or more.         The fully aromatic polyester according to any one of claims 1 to 6, the value of [melting point-crystallization temperature] is 20 ° C or higher.         A polyester resin composition containing the wholly aromatic polyester according to any one of claims 1 to 7.         A polyester molded article obtained by molding the wholly aromatic polyester or polyester resin composition according to any one of claims 1 to 8 in the patent application scope.