JP2020097712A - Fully aromatic polyester amide, polyester amide resin composition, and polyester amide molding - Google Patents

Abstract

To provide a fully aromatic polyester amide which has a high strength and a high elastic modulus.SOLUTION: In the fully aromatic polyester amide, the content of the constitutional units of the formula (I) is 40-70 mol%, the total content of the constitutional units represented by the formulas (I), (II) and (III) is 100 mol%, and the ratio of the content of the constitutional units represented by the general formula (II) to the content of the constitutional units represented by the general formula (III) is from 0.5 to 2.SELECTED DRAWING: None

Description

The present invention relates to a wholly aromatic polyesteramide, a resin composition containing the wholly aromatic polyesteramide, and a molded article thereof.

Liquid crystalline polymers have excellent fluidity, mechanical strength, heat resistance, chemical resistance, electrical properties, etc. in a well-balanced manner and are therefore widely used as high-performance engineering plastics. As the liquid crystal polymer, for example, a wholly aromatic polyester obtained by copolymerizing 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and optionally other monomer components is known. In addition, a wholly aromatic polyester amide in which an amino group is introduced into a wholly aromatic polyester is known. Since a wholly aromatic polyester amide forms hydrogen bonds between polymer chains, it tends to be superior in performance such as mechanical strength, heat resistance, moldability, and elastic modulus as compared with wholly aromatic polyester.

Among the wholly aromatic polyester amides, those using three specific raw material monomers include, for example, copolymerizing 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 3-aminobenzoic acid. What is obtained is known (Patent Document 1).

JP, 2004-339462, A

However, in the wholly aromatic polyester amide represented by Patent Document 1, when the wholly aromatic polyester amide obtained by combining and copolymerizing the above-mentioned three specific types is used, the tensile elastic modulus is not sufficient.

The proportion of amide bonds is increased by increasing the amount of a monomer containing an amino group (for example, 3-aminobenzoic acid or 4-aminobenzoic acid), and the proportion of hydrogen bonds formed by hydrogen atoms of amide bonds is increased. There is a method of increasing the tensile elastic modulus by increasing the value.

However, if the amount of the amino group-containing monomer increases, the polymer may harden and be difficult to discharge. Therefore, there is a problem that the proportion of hydrogen bonds having a strong bonding force cannot be easily increased.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a wholly aromatic polyester amide having a high tensile elastic modulus.

The present inventors, as a result of earnest research to achieve the above object, the use of a plurality of monomers containing an amino group, increasing the proportion of amide bonds by increasing the proportion of amide bonds, It has been found that a rigid polymer can be obtained and is effective for achieving the above-mentioned object.

One aspect of the present invention for achieving the above object is as follows.

(1) Containing structural units represented by the following general formulas (I), (II) and (III), the structural unit represented by general formula (I) is 40 to 70 mol% based on all structural units, The total of the structural units represented by the general formula (II) and the general formula (III) is 30 to 60 mol %, and the total of the structural units represented by the general formulas (I), (II), and (III). Is 100 mol% and the ratio of the constitutional unit represented by the general formula (II) to the constitutional unit represented by the general formula (III) is 0.5 to 2.

(2) The wholly aromatic polyester amide according to (1), which has a tensile elastic modulus of 40 cN/dtex or more.

(3) A polyesteramide resin composition containing the wholly aromatic polyesteramide according to (1) or (2).

(4) A polyesteramide molded article formed from the wholly aromatic polyesteramide described in (1) or (2) or the polyesteramide resin composition described in (3).

(5) The polyesteramide molded article according to (4), wherein the molded article is a fiber.

According to the present invention, a wholly aromatic polyesteramide having a high elastic modulus can be provided.

<Whole aromatic polyester amide>
The raw materials necessary for forming the wholly aromatic polyester amide constituting one aspect of this embodiment will be described below.

One of the raw materials used in one aspect of this embodiment contains a structural unit represented by the following general formula (I). Further, another one of the raw materials used in one aspect of the present embodiment contains a structural unit represented by the following general formula (II). Furthermore, another one of the raw materials used in one aspect of the present embodiment contains a structural unit represented by the following general formula (III).

The monomer from which the structural unit represented by the general formula (I) is derived is, for example, 6-hydroxy-2-naphthoic acid (hereinafter, also referred to as “HNA”).

The monomer from which the structural unit represented by the general formula (II) is derived is, for example, 4-aminobenzoic acid (hereinafter, also referred to as “pABA”) or 4-acetamidobenzoic acid (hereinafter, also referred to as “pAABA”). ) Etc.
Note that the reaction is milder when pAABA is used than when pABA is used. Therefore, pAABA is used in Examples described later.

The monomer from which the structural unit represented by the general formula (III) is derived is, for example, 3-aminobenzoic acid (hereinafter also referred to as “mABA”) or 3-acetamidobenzoic acid (hereinafter also referred to as “mAABA”). .) etc.
In addition, since the reaction is milder when mABA is used than when mABA is used, mAABA is used in Examples described later.

In the wholly aromatic polyester amide according to one aspect of the present embodiment obtained by polycondensing raw materials containing the constituent units represented by the general formulas (I), (II), and (III), the polymerization ratio of each constituent unit Is important for developing an excellent tensile elastic modulus, which is the object of one aspect of the present embodiment.

Specifically, the structural unit represented by the general formula (I) is 40 to 70 mol% with respect to all the structural units, and the total of the structural units represented by the general formula (II) and the general formula (III). Is 30 to 60 mol %, and the total of the constituent units represented by general formulas (I), (II), and (III) is 100 mol %, based on the constituent units represented by general formula (III). The ratio of the structural unit represented by the general formula (II) is 0.5 to 2. The wholly aromatic polyester amide according to one aspect of the present embodiment has a tensile elastic modulus of preferably 40 cN/dtex or more, more preferably 45 cN/dtex or more, and further preferably 50 cN/dtex or more.

The wholly aromatic polyester amide of the present embodiment contains 40 to 70 mol% of the structural unit represented by the general formula (I) based on all the structural units. When the content of the structural unit represented by the general formula (I) is within the above range, a rapid torque increase due to thickening at the time of polymerization is unlikely to occur, and stable polymerization is possible, which is preferable. The content of the structural unit represented by the general formula (I) is preferably 45 to 70 mol%, more preferably 45 to 65 mol%, further preferably 50 to 65 mol%, and particularly preferably 50 to 60 mol%. Is.

In the present embodiment, the total content of the structural units represented by general formula (II) and general formula (III) is 30 to 60 mol %. When the total content is within the above range, hydrogen bonds are appropriately formed, so that it is possible to obtain a wholly aromatic polyester amide having a high tensile elastic modulus while ensuring manufacturability. The total content is preferably 30 to 55 mol %, more preferably 35 to 55 mol %, further preferably 35 to 50 mol %, and particularly preferably 40 to 50 mol %.

A raw material containing a structural unit represented by the general formula (II) and a raw material containing a structural unit represented by the general formula (III) are used to form a structural unit containing an amino group with respect to all the structural units of the wholly aromatic polyester amide. Is preferably increased. As described above, by using two kinds of raw materials containing a constitutional unit containing an amino group, the molecular cohesive force is lowered, and the softening point is lowered accordingly. Only one raw material containing a constitutional unit containing an amino group is the same. Thickening of the raw material can be suppressed as compared with the case where the amount is used. Therefore, it is possible to prevent the polymer from solidifying and being unable to be discharged, so that the wholly aromatic polyesteramide cannot be produced.

In the present embodiment, the ratio of the constitutional unit represented by the general formula (II) to the constitutional unit represented by the general formula (III) is 0.5 to 2. When the ratio is within the above range, the thickening of the raw material is suppressed, so that the wholly aromatic polyester amide can be obtained. The ratio is preferably 0.5 to 1.5, more preferably 0.75 to 1.5.

In addition, it is preferable to perform polycondensation with three components including only the structural units represented by the general formulas (I), (II), and (III). When polycondensation is performed only with the above-mentioned three components, the uniformity of the raw material is maintained and the decrease in melting point can be suppressed.

As described above, the wholly aromatic polyester amide having a high tensile elastic modulus can be produced by setting the polymerization ratio of each structural unit within the above range.

Next, the properties of the wholly aromatic polyester amide will be described. The wholly aromatic polyester amide of this embodiment exhibits optical anisotropy when melted. Having optical anisotropy when melted means that the wholly aromatic polyester amide of the present embodiment is a liquid crystalline polymer.

In the present embodiment, the wholly aromatic polyesteramide is a liquid crystalline polymer, which is an essential element for the wholly aromatic polyesteramide to have both thermal stability and easy processability. The wholly aromatic polyester amide composed of the structural units represented by the general formulas (I), (II), and (III) forms an anisotropic molten phase depending on the structural components and the sequence distribution in the polymer. Some polymers do not exist, but the polymer of the present embodiment is limited to wholly aromatic polyester amides that exhibit optical anisotropy when melted.

The property of melting anisotropy can be confirmed by a conventional polarization inspection method using a crossed polarizer. More specifically, the melt anisotropy can be confirmed by using a polarizing microscope manufactured by Olympus Co., Ltd., melting a sample placed on a hot stage manufactured by Rincom, and observing the sample under a nitrogen atmosphere at a magnification of 150 times. Liquid crystalline polymers are optically anisotropic and transmit light when inserted between orthogonal polarizers. When the sample is optically anisotropic, for example, polarized light is transmitted even in a molten still liquid state.

A nematic liquid crystalline polymer causes a significant decrease in viscosity above its melting point, so that generally exhibiting liquid crystallinity at the melting point or above is an index of processability. The melting point is preferably as high as possible from the viewpoint of heat resistance, but considering heat deterioration during melt processing of the polymer, heating capacity of the molding machine, etc., a melting point of 380° C. or less is a preferable index. The melting point is preferably 260 to 370°C, more preferably 270 to 370°C, and further preferably 280 to 370°C.

Next, the method for producing the wholly aromatic polyester amide of the present embodiment will be described. The wholly aromatic polyester amide of this embodiment is polymerized by 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 or the like, or a combination of two or more thereof is used. The melt polymerization method or the combination of the melt polymerization method and the solid phase polymerization method. Is preferably used.

In the present embodiment, at the time of polymerization, an acylating agent for a polymerization monomer or a monomer whose terminal is activated as an acid chloride derivative can be used. Examples of the acylating agent include fatty acid anhydride such as acetic anhydride.

Various catalysts can be used in these polymerizations, and representative examples thereof include potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris(2). , 4-pentanedionato)cobalt (III) and other metal salt catalysts, and N-methylimidazole, 4-dimethylaminopyridine and other organic compound catalysts. The amount of catalyst used is generally about 0.001 to 1% by weight, especially about 0.003 to 0.2% by weight, based on the total weight of the monomers.

[Polyesteramide resin composition]
The wholly aromatic polyesteramide of the present embodiment can be blended with various fibrous, powdery, and plate-like inorganic and organic fillers depending on the purpose of use to form a polyesteramide resin composition.

Examples of the inorganic filler to be added to the polyesteramide resin composition of the present embodiment include fibrous, granular and plate-like ones.

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

Further, as the particulate inorganic filler, carbon black, graphite, silica, quartz powder, glass beads, milled glass fiber, glass balloon, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, wollast. Silicates such as knights, iron oxides, titanium oxide, zinc oxide, antimony trioxide, oxides of metals such as alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, sulfuric acid of metals such as calcium sulfate and barium sulfate. Examples thereof include salts, other ferrites, silicon carbide, silicon nitride, boron nitride, and various metal powders.

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

Examples of the organic filler to be blended in the polyesteramide resin composition of the present embodiment include heat resistant and high strength synthetic fibers such as aromatic polyester fibers, liquid crystalline polymer fibers, aromatic polyamide and polyimide fibers. ..

These inorganic and organic fillers can 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 view of having both mechanical strength, dimensional accuracy and electrical properties. Particularly preferably, glass fibers are used as the fibrous filler, and mica and talc are used as the plate-shaped filler, and the compounding 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 wholly aromatic polyester amide. It is a department. By combining glass fiber with mica or talc, the polyesteramide resin composition is particularly remarkably improved in heat distortion temperature, mechanical properties and the like.

When using these fillers, a sizing agent or a surface treatment agent can be used if necessary.

As described above, the polyesteramide resin composition of the present embodiment contains, as an essential component, the wholly aromatic polyesteramide of the present embodiment and, if necessary, an inorganic or organic filler, but the effect of the present embodiment is impaired. Other components may be included as long as the content does not exist. Here, the other component may be any component, and examples thereof include other resins, antioxidants, stabilizers, pigments, additives such as crystal nucleating agents, and the like.

The method for producing the polyesteramide resin composition of the present embodiment is not particularly limited, and the polyesteramide resin composition can be prepared by a conventionally known method.

[Polyesteramide moldings]
The polyesteramide molded article of this embodiment is obtained by molding the wholly aromatic polyesteramide or polyesteramide resin composition of this embodiment. 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, rotational molding, gas injection molding, and inflation molding.

The polyesteramide molded article of this embodiment has a high tensile elastic modulus because it is formed by molding the above-mentioned wholly aromatic polyesteramide or polyesteramide resin composition of this embodiment.

Further, the wholly aromatic polyester amide and polyester amide resin composition of the present embodiment has excellent moldability, and thus can be processed into various three-dimensional molded products, fibers, films and the like.

Preferred applications of the polyesteramide molded product of the present embodiment having the above properties are a connector, a CPU socket, a relay switch part, a bobbin, an actuator, a noise reduction filter case, an electronic circuit board or a heat fixing roll for OA equipment, Examples include ropes, cords and protective clothing.

Hereinafter, the present embodiment will be described more specifically by way of examples, but the present embodiment is not limited to the following examples.

A wholly aromatic polyesteramide was prepared by the method described below.

(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 charging port, a nitrogen introducing port, and a decompression/outflow line, and nitrogen substitution was started. The following (I) to (III) are monomers from which the structural units of the general formulas (I) to (III) are derived.
(material)
(I) 6-Hydroxy-2-naphthoic acid (HNA): 97.6 g (50 mol%)
(II) 4-acetamidobenzoic acid (pAABA): 46.5 g (25 mol%)
(III) 3-acetamidobenzoic acid (mAABA): 46.5 g (25 mol%)
Potassium acetate (fatty acid metal salt catalyst): 11 mg
Acetic anhydride (acylating agent): 54 g (1.02 times the hydroxyl equivalent of HNA)
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 is further raised to 330° C. over 3.3 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes to distill off acetic acid, excess acetic anhydride, and other low-boiling components. Condensation was performed.

<Evaluation>
In the above-mentioned polycondensation, after the stirring torque reached a predetermined value, nitrogen was introduced to change from a reduced pressure state to a normal pressure to a pressurized state, and it was evaluated whether the polymer was discharged from the lower portion of the polymerization container. The evaluation results are shown in Table 1. When discharged, pelletizing was performed to obtain resin pellets.

[Tensile modulus]
The obtained resin pellets were stretched at 300° C. using a capillograph (CHAPILOGRAPH 1D, manufactured by Toyo Seiki Co., Ltd.) equipped with a melt tension measuring device to obtain fibers stretched 45 times. The obtained fiber was subjected to a tensile test with a tensile tester (TENSILON RTM-100, manufactured by Orientec Co., Ltd.) to calculate the tensile elastic modulus. The evaluation results are shown in Table 1.

(Examples 2, 3 and Comparative Examples 1-5, 7-9)
Polycondensation was carried out in the same manner as in Example 1 except that the kinds of raw material monomers and the charging ratio (mol %) were as shown in Table 1. Then, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

(Comparative example 6)
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 charging port, a nitrogen introducing port, and a decompression/outflow line, and nitrogen substitution was started.
(material)
(I) 6-Hydroxy-2-naphthoic acid (HNA): 113.1 g (60 mol%)
4-Hydroxybenzoic acid (pHBA): 35.9 g (20 mol%)
3-Hydroxybenzoic acid (mHBA): 35.9 g (20 mol%)
Potassium acetate (fatty acid metal salt catalyst): 11 mg
Acetic anhydride (acylating agent): 63 g (1.02 times the hydroxyl equivalent of the total of HNA, pHBA, and mHBA)
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 is further raised to 350° C. over 3.7 hours, and then pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes to distill off acetic acid, excess acetic anhydride, and other low-boiling components. Condensation was performed. Then, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

(Comparative Example 10)
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 charging port, a nitrogen introducing port, and a decompression/outflow line, and nitrogen substitution was started.
(material)
(I) 6-hydroxy-2-naphthoic acid (HNA): 53.4 g (25 mol%)
(II) 4-acetamidobenzoic acid (pAABA): 101.7 g (50 mol%)
4-Hydroxybenzoic acid (pHBA): 39.2 g (25 mol%)
Potassium acetate (fatty acid metal salt catalyst): 11 mg
Acetic anhydride (acylating agent): 59 g (1.02 times the hydroxyl equivalent of the total of HNA and pHBA)
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 is further raised to 350° C. over 43.7 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes to distill off acetic acid, excess acetic anhydride, and other low boiling components. Condensation was performed. Then, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

In addition, "discharging property" in the table indicates whether or not the polymer is discharged from the polymerization container by ◯ (discharging possible) or × (not discharging possible).

It can be seen from Table 1 that the polymers are discharged in all of Examples 1, 2, 3 and Comparative Example 6, but in all of the other Comparative Examples, the polymer is solidified and is not discharged. In addition, it can be seen that Examples 1, 2 and 3 in which the raw material monomers containing pAABA and mAABA are charged have a high tensile elastic modulus of the polymer and have an excellent tensile elastic modulus. In Comparative Example 6, the raw material monomer does not contain an amino group, and therefore it is considered that no improvement in the tensile elastic modulus due to hydrogen bonding could be confirmed.

The tensile elastic modulus tends to increase as the proportion of the amide amount increases. Further, it is understood that the amount of amide has an appropriate range, and the polymer cannot be produced unless the amount is in the range.

Claims (5)

Including the structural units represented by the following general formulas (I), (II) and (III), the structural unit represented by the general formula (I) is 40 to 70 mol% based on all structural units, and the general formula ( The total of the structural units represented by II) and the general formula (III) is 30 to 60 mol %, and the total of the structural units represented by the general formulas (I), (II), and (III) is 100 mol. %, and the ratio of the constitutional unit represented by the general formula (II) to the constitutional unit represented by the general formula (III) is 0.5 to 2.

The wholly aromatic polyester amide according to claim 1, which has a tensile modulus of 40 cN/dtex or more. A polyesteramide resin composition containing the wholly aromatic polyesteramide according to claim 1. A polyester amide molded article formed from the wholly aromatic polyester amide according to claim 1 or 2, or the polyester amide resin composition according to claim 3. The polyesteramide molded article according to claim 4, wherein the molded article is a fiber.