JPH0337227A - Wholly aromatic polyamide polyester block copolymer - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer markedly improved in properties such as toughness, strengths, modulus and anisotropy by forming a block copolymer comprising a block of a wholly aromatic polyamide and a block of a wholly aromatic polyester. CONSTITUTION:A block copolymer comprising a wholly aromatic polyamide block (A) obtained from at least one compound having a structure of any one of formulas I-III and at least one compound having a structure of any one of formulas IV-VI and a wholly aromatic polyester block (B) obtained from at least one compound having a structure of any one of formulas I-III and a compound having a structure of formula VII. In the formulas, R is a substituent selected from among H, a halogen atom and a 1-8C aliphatic or aromatic hydrocarbon group; (p) and (q) are each 1-4; and X is a 1-8C aliphatic, alicyclic or aromatic hydrocarbon group, S, SO2, O or CO. When compared with a resin composition obtained by blending a wholly aromatic polyamide fiber with a wholly aromatic polyester, the above block copolymer is markedly improved in properties such as toughness, strengths, modulus and anisotropy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a novel fully aromatic polyamide that is a melt-formable material with high elasticity, high strength, and high heat resistance, and which has improved toughness and anisotropy. It relates to polyester block copolymers.

[Prior Art] A wholly aromatic polyamide obtained from an aromatic dicarboxylic acid and an aromatic diamine is known as a highly elastic fiber, and its manufacturing method is disclosed, for example, in Japanese Patent Publication No. 35-13427.

However, since fully aromatic polyamides are insoluble and infusible, they cannot be melt-kneaded and processed, so their use as plastic materials has been limited despite their high elasticity and high strength properties.

For this reason, it is currently used as a fiber reinforcing material by blending it with brass materials such as polyester and polyamide.

On the other hand, polyester obtained from aromatic dicarboxylic acids and aromatic dihydroxy compounds such as bisphenols is easy to melt mold and is strong, so it is used for various purposes, but it has sufficiently high elastic modulus and strength. However, in order to improve these drawbacks, reinforcing with the aforementioned wholly aromatic polyamide fibers, carbon fibers, glass fibers, etc. is widely practiced.

However, when reinforced with fibers and used, although a material with high elasticity and high strength is obtained, the toughness of the material is lost and the anisotropy increases due to the orientation of the fibers.

For this reason, a copolymer consisting of a wholly aromatic polyamide and a wholly aromatic polyester may be considered, but according to the studies of the present inventors, ordinary random copolymers hardly improve the elastic modulus and are only brittle materials. I couldn't get it.

[Problems to be Solved by the Invention] The purpose of the present invention is to overcome the problems of the prior art as described above, and to create a completely aromatic product that has excellent mechanical properties, particularly toughness, high elasticity, and less anisotropy. An object of the present invention is to provide a group polyamide polyester copolymer.

[Means for Solving the Problems] As a result of intensive studies, the present inventors have found that the above problems can be overcome by creating a block copolymer consisting of a block of wholly aromatic polyamide and a block of wholly aromatic polyester. They discovered this and arrived at the present invention.

That is, the present invention provides at least one type of compound having the structure shown in [81 formulas (i) to (iii) and formulas (iv) to
A wholly aromatic polyamide block obtained from at least one type of compound having the structure shown in (vi) and (i) (ii)-(iii) (iv) (v) (
vi) (R is a substituent selected from the group consisting of hydrogen, halogen, or an aliphatic or aromatic hydrocarbon having 1 to 8 carbon atoms.) [Structures shown in formulas (i) to (iii) of 61] Block (vii) of a wholly aromatic polyester obtained from at least one compound having the structure shown in formula (vii) (p and q are integers of 1 to 4).

X is an aliphatic, alicyclic, or aromatic hydrocarbon having 1 to 8 carbon atoms, or -5--3O2-10--CO-. R is as described above. ) This invention relates to a block copolymer consisting of:

The block copolymer of the present invention has a wholly aromatic polyamide block M (hereinafter sometimes referred to as "M") and a wholly aromatic polyester block E (hereinafter sometimes referred to as "E") in the polymer main chain. It is sufficient that it is contained as a main component in the polyester, and a random structure or alternating structure consisting of polyamide and polyester may be included between each block or at the end.

Preferred structures are ME%MEM, EME, (ME)n(
Here, n indicates a positive integer of 2 or more) as an essential structure, and more preferable ones are ME%MEM,
It has a repeating EME structure.

Further, the ratio of M and E in the copolymer is 10 to 90% by weight, preferably 30 to 70% by weight.

The following raw materials can be exemplified as raw materials used for producing the wholly aromatic polyamide polyester block copolymer of the present invention.

Terephthalic acid having the structure shown in formula (i),
Terephthalic acid dialkyl esters (e.g., terephthalic acid dimethyl ester, terephthalic acid diethyl ester,
terephthalic acid dipropyl ester), diester of terephthalic acid and phenol, terephthalic acid dichloride,
Isophthalic acid, isophthalic acid dialkyl esters (e.g. isophthalic acid dimethyl ester, isophthalic acid diethyl ester, isophthalic acid dipropyl ester), isophthalic acid diesters with phenol, isophthalic acid dichloride, phthalic acid, phthalic acid dialkyl esters (e.g. phthalic acid, 2,6-naphthalene dicarboxylic acid has the structure shown in formula , 2.6-naphthalene dicarboxylic acid dichloride, dialkyl esters of 2.6 naphthalene dicarboxylic acid, diphenyl ester of 2.6 naphthalene dicarboxylic acid, 1.5-naphthalene dicarboxylic acid, 1.5-naphthalene dicarboxylic acid dichloride, 1. Examples include 5-naphthalene dicarboxylic acid dialkyl esters, 15-naphthalene dicarboxylic acid diphenyl ester, etc. Those having the structure shown in formula (ni) include 1.4-naphthalene dicarboxylic acid, 1.3-naphthalene dicarboxylic acid, 2.3 Examples include -naphthalene dicarboxylic acid, and dialkyl esters, diphenyl esters, and dichlorides of these three dicarboxylic acids (1,4-1, -3-1 or 2,3-naphthalene dicarboxylic acid); Preferred among these are terephthalic acid dichloride and isophthalic acid dichloride.

In addition, para-phenylene diamine, meta-phenylene diamine, 5-chloro-para-phenylene diamine, 5-chloro-meth-phenylene diamine, 5-phenyl-para-phenylene diamine, 5-phenyl-meth Examples include phenylenediamine, paratolylenediamine, metatolylenediamine, etc.
2,6-naphthalenediamine, 1,5-naphthalenediamine, II 8 having the structure shown in formula [v]
-Naphthalenediamine is an example, and 1. 4-naphthalenediamine,
Examples include naphthalene diamines such as 1.3-naphthalene diamine, L 2-naphthalene diamine, and 2.3-naphthalene diamine, diisocyanates corresponding to these diamines, and diamides with aliphatic carboxylic acids such as acetic acid. However, among these, preferred are heterophenylenediamine, metaphenylenediamine, and metatolylenediamine, and particularly preferred is metatolylenediamine.

Formula (i) used for the production of fully aromatic polyamide blocks
Compounds shown in ~(iii) and formulas (iv) ~ (vi)
One or more of the compounds shown in may be used in combination.

Furthermore, it has the structure shown in formula (vii).Te2.
2-His(hydroxyphenyl)propane (also known as bisphenol-A), tetramethylbisphenol-A
1-tetrabromobisphenol-A, 2.2-bis(hydroxyphenyl)methane, 2.2-bis(hydroxyphenyl)hexane, bis(hydroxyphenyl)diphenylmethane, 1.1-bis(hydroxyphenyl)-
1-phenylethane, 2.2-bis(hydroxyphenyl)sulfone (also known as bisphenol-S), tetramethylbisphenol-81tetrabromobisphenol-8, thiobiphenol, tetramethylthiobiphenol, tetrabromothiobiphenol, 2. 2-bis(
Examples include bisphenols such as hydroxyphenyl)ether and 2,2-bis(hydroxyphenyl)ketone. Among these, 2,2-bis(hydroxyphenyl)propane and tetramethylbisphenol are preferred.
A12.2-bis(hydroxyphenyl)sulfone, thiobiphenol, 2,2-bis(hydroxyphenyl)
These are bisphenols such as ether and 2,2-bis(hydroxyphenyl)ketone.

Formula N used for the production of blocks of wholly aromatic polyester
The compounds shown in ) to (ii) and the compound shown in formula (vii) may each be used in combination of one or more types.

In addition, the polyester block portion of the block copolymer of the present invention is prepared by an interfacial polycondensation method, a dehydrochlorination method, or a transesterification method, and the polyamide block portion is prepared by an interfacial polycondensation method, a dehydrochlorination method, or a transesterification method.
It is produced by methods such as direct amidation method, acid amidation exchange method, and condensation method of dicarboxylic acid and diisocyanate compound.

A specific method for producing the block copolymer of the present invention, for example, if carried out by interfacial polycondensation method, is as follows.

That is, first, an alkaline aqueous solution in which bisphenols are dissolved and an aromatic dicarboxylic acid dichloride dissolved in an organic solvent are mixed in the presence or absence of a phase transfer catalyst such as a quaternary ammonium salt or a quaternary phosphonium salt. The polyester portion of block E is produced by the reaction.

As the alkali for dissolving bisphenols, for example, caustic soda or caustic potash is used. The organic solvent used here is a chlorinated hydrocarbon such as methylene chloride, chloroform, dichloroethane, trichloroethane.

Next, aromatic diamines and aromatic dicarboxylic acid dichloride dissolved in an organic solvent are added to the produced polyester solution and further reacted to obtain a block copolymer.

In the second stage polymerization reaction, a more preferred method is to add aromatic diamines as an aqueous alkaline solution and add aromatic dicarboxylic acid dichlorides dissolved in the above-mentioned chlorinated hydrocarbon or organic solvent such as cyclohexanone.

At this time, it is more preferable to add aromatic dicarboxylic acid dichloride dissolved in chlorinated hydrocarbon or cyclohexanone prior to the aromatic diamine.

On the other hand, as a method different from the above method, after polymerizing the polyamide portion of block M in the first stage,
It is also possible to produce the block copolymer of the present invention by a method of polymerizing polyesters.

Furthermore, it is also possible to repeat polymerization alternately in the order of block E, block M1, block E to produce EME... body, and repeat polymerization alternately in the order of block E, block M1, block E to produce EME... body. It is also possible to manufacture.

In these polymerization methods, substituted phenols represented by tert-butylphenol, unsubstituted phenols, halides of aromatic or aliphatic carboxylic acids, etc. are effective as terminal capping agents at each stage including the start and end of the reaction. can be used.

In addition, in order to control the length of each segment of M and E, the reaction time, temperature, type of solvent, and charging ratio of each component, that is, the formula (
Compounds shown in i) to (iii) and formulas (iv) to (vi)
The charging ratio of the compound shown in and formulas (i) to (iii)
It is also a useful method to vary the charging ratio of the compound shown in and the compound shown in formula (vii).

The wholly aromatic polyamide polyester block copolymer of the present invention has both high elasticity and toughness and has little anisotropy, so it can be used alone for electrical, electronic, automotive, and other applications.

The copolymer of the present invention may contain other resins, elastomers, or various additives such as flame retardants, flame retardant aids, stabilizers, ultraviolet absorbers, plasticizers, lubricants, pigments, fillers, etc., as desired.
Other ingredients can be added as appropriate.

Although there are no particular restrictions on the blending method, a method of melt-kneading various compounding agents and the block copolymer of the present invention using an extruder or the like is particularly suitable.

Examples of the other resins include polystyrene resin, epoxy resin, phenoxy resin, polycarbonate, polyphenylene ether, polyester, polyamide, polyether sulfone, polysulfone, polyether ether ketone, polyphenylene sulfide, etc., and compounds containing two or more thereof. One or more types of polymers may be mentioned.

Polyesters to be blended as the other resins include polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate, in addition to those having the structure forming block E of the present invention, and polycarbonates as other resins include formula (vii). The dihydroxy aromatic compounds shown, preferably polycarbonates derived from bisphenol A and phosgene, polyester carbonates which are copolymers of polycarbonate and polyester, and also other resins such as boria □ are used as repeating units in the main chain. This includes anything that has an amide bond, but specific examples include nylon-6, nylon-6,6, nylon-12, nylon-4,6, and nylon-6,10.
, nylon-6, 12, nylon-11, nylon-1
0,11, crystalline nylons such as nylon-MXD6,
Furthermore, it includes non-quality nylon, which is so-called transparent nylon. Furthermore, the elastomer component used in the copolymer of the present invention is an elastomer in a general sense, and includes, for example,
“Property” by A. V. Tobolski.
s and Structure of Polymer
s'' (John Wily & 5ons.

Inc., 1960) on pages 71 to 78, with notes on elastomers and elastomers having a Young's modulus of 10' to 10 "dynes Ham' (0,1 to 1
020 kg/cm').

Specific examples of elastomers include A-B-A" type elastomeric block copolymers, A-B-A ° type elastomeric copolymers in which the double bond of the polybutadiene portion is hydrogenated, polybutadiene, polyisoprene, Copolymer of diene compound and vinyl aromatic compound, 2) IJ rubber,
Ethylene-propylene copolymer, ethylene-propylene-diene copolymer (EPDM), thiol rubber, polysulfide rubber, acrylic acid rubber, polyurethane rubber, grafted products of butyl rubber and polyethylene, hard segment has a crystal structure of polyester and soft segment has a crystal structure of polyester. Examples include polyester elastomer, polyamide elastomer, etc., which have a crystal structure of polyether.

Examples of the various additives mentioned above include flame retardants such as triphenyl phosphate, tricresyl phosphate, phosphate obtained from a mixture of isopropylphenol, phenol, and phosphorus oxychloride, and difunctional compounds such as benzohydroquinone or bisphenol-A. Phosphates obtained from phenol and other alcohols or phenols and phosphorus oxychloride, bromination represented by decabromo biphenyl ether, hexabromo biphenyl, pentabromotoluene, decabromo biphenyl ether, hexabromobenzene, brominated polystyrene, etc. Compounds, nitrogen-containing compounds such as melamine derivatives, and nitrogen-containing phosphorus compounds such as phosphazene can be mentioned.

Additionally, flame retardant aids may be used, examples of which include antimony, boron, zinc or iron compounds.

Other additives include stabilizers such as sterically hindered phenols and phosphite compounds, ultraviolet absorbers such as oxalic acid diamide compounds, and sterically hindered amine compounds, polyethylene wax, polypropylene wax,
Examples include lubricants such as paraffin, pigments such as titanium oxide, and zinc sulfide.

Also, glass fiber (e.g. milled fiber, glass powder, etc.), asbestos, wollastonite, mica,
It is also possible to use inorganic fillers such as talc and potash titanate whiskers, and organic fillers such as carbon fibers and aramid fibers in combination.

[Example] Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

Note that elongation, tensile strength, and tensile modulus were all measured according to ASTM D638.

The glass transition temperature (Tg) was measured using a scanning thermal analyzer (DSC).
).

In the present examples and comparative examples, the following raw materials were used.

Bisphenol A (manufactured by Mitsui Toatsu Chemical ■) Terephthalic acid chloride (manufactured by Mitsubishi Gas Chemical ■) Isophthalic acid chloride (manufactured by Mitsubishi Gas Chemical ■) m-) Louisendiamine (manufactured by Tokyo Kasei Kogyo ■) P-phenylenediamine (Kokan (Chemical reagent) These examples are for illustrating the present invention, and the present invention is not limited thereto.

Example 1 5.7 grams of bisphenol A, 2.7 grams of sodium hydroxide.
1 gram, 300 mjl containing 0.5 grams of hydrosulfide and 0.5 grams of tetra-n-butylammonium bromide! The aqueous solution was charged into a reactor equipped with a stirrer, and a solution of 2.54 g of terephthalic acid chloride and 2.54 g of isophthalic acid chloride dissolved in 150 ml of chloroform was added while stirring at room temperature. Thereafter, the mixture was stirred at room temperature for 7 minutes, and then 200 ml of a chloroform solution containing 5.1 g of isophthalic acid chloride and 200 ml of an aqueous solution containing 3.5 g of m-tolylenediamine and 2.1 g of sodium hydroxide were added. Continued stirring.

Subsequently, the reaction solution was poured into 1000 ml of methanol and washed with stirring. After that, it dries to a white polymer14.
Obtained 3 grams.

The obtained polymers were based on aromatic polyester <Tg of 201.5°C, and based on aromatic polyester <Tg of 24°C.
It was observed at 7.1°C.

The above white polymer was pressed at 350°C to obtain a tensile test piece with a thickness of 03 nm. Using this test piece, tensile strength,
Elongation and tensile modulus were measured. The results are shown in Table 1.

Next, the blockiness mm of the copolymer of the above white polymer is
Therefore, we conducted the following experiment.

0.5 g of the polymer obtained in this example was mixed with chloroform 1
0m1! and further soaked in monoethylamine 1. After dropping 0 grams, it was left to stand for 24 hours. Thereafter, it was filtered to obtain 0.28 g (recovery rate 56.0%) of a dried polymer (logarithmic viscosity 1.55).

From this, it is determined that the polymer of Example 1 is a block copolymer.

Incidentally, when the wholly aromatic polyamide portion of Example 1 was independently polymerized, the logarithmic viscosity was measured and found to be 1.62.

The above logarithmic viscosity is 0.5 per 100ml of solution at 30℃
Measurements were made in sulfuric acid at gram polymer concentrations. Note that the logarithmic viscosity is expressed by the following formula.

Example 2 3.05 grams of m-) lylene diamine of Example 1 was added to m
-) 15.7 g of a white polymer was obtained in the same manner as in Example 1 except that 1.83 g of lylene diamine and 1.08 g of p-phenylene diamine were used.

The resulting polymers were based on aromatic polyester <Tg of 201.5°C and based on aromatic polyamide <Tg of 253°C.
．． It was observed at 7°C.

Using a test piece obtained by pressing in the same manner as in Example 1, tensile strength, elongation, and tensile modulus were measured. The results are shown in Table 1.

Comparative Example 1 5.70 grams of bisphenol A, 4 grams of sodium hydroxide
．． 20 grams, m-toluylenediamine 3.05 grams, hydrosulfide 050 grams and tetra-n
-butylammonium bromide 0.50 grams 45
0 ml of the aqueous solution was put into a reactor equipped with a stirrer, and while stirring, a chloroform solution containing 2.54 g of terephthalic acid chloride and 7.64 g of isophthalic acid chloride was added at room temperature.

Thereafter, the mixture was stirred at room temperature for 15 minutes.

After the reaction was completed, the reaction solution was stirred and washed with 1000 mJ of methanol and dried to obtain 14.2 g of a white polymer.

This polymer was hot pressed to prepare a test piece for measuring physical properties similar to that in Example 1. Next, each physical property was measured by the method shown in Example 1.

The measurement results are shown in Table 1.

Next, the following experiment was conducted to confirm the blocking properties of the polymer obtained in this comparative example.

Polymer obtained in this comparative example 0. 5 grams was immersed in 40 ml of chloroform, and then 1. After dropping 0 grams, it was left to stand for 24 hours. After that, a filtration operation was performed, but no polymer was recovered.

Comparative Example 2 Using the raw material composition of Example 2, the same polymerization operation as described in Comparative Example 1 was performed to obtain a polymer. The physical properties of the obtained polymer were measured. The measurement results are shown in Table 1.

Example 3 5.7 grams of bisphenol A, 2.7 grams of sodium hydroxide.
A 300 ml aqueous solution containing 1 g of hydrosulfide, 0.5 g of tetra-n-butylammonium bromide and 0.5 g of tetra-n-butylammonium bromide was charged into a reactor equipped with a stirrer, and 2.54 g of terephthalic acid chloride and isophthalic acid were added to 150 ml of chloroform at room temperature with stirring. A solution containing 2.54 grams of acid chloride was added.

It was then stirred at room temperature for 7 minutes, followed by a solution of 200 ml of chloroform containing 2.2 g of isophthaloyl chloride, 1.3 g of m-tolylenediamine and 0.0 g of sodium hydroxide. 200 ml of an aqueous solution containing 9 grams was added and stirring was continued at room temperature. After that, add 1000ml of the reaction solution.
The mixture was poured into methanol solution and washed with stirring. Subsequent drying yielded 115 grams of white polymer. The resulting polymer is based on an aromatic polyester and has a Tg of <201.
Based on fully aromatic polyamide at 5°C < Tg is 4469°C
was recognized.

The physical properties of the above white polymer were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

Example 4 In the second stage polyamide polymerization of Example 3, m-)
The amount of lylene diamine was 4.58 grams, and the amounts of sodium hydroxide and isophthaloyl chloride were each 3.1 grams.
5 grams and 7.63 grams, and the method described in Example 3 was repeated to obtain 12.9 grams of a white polymer.

The resulting white polymer is based on an aromatic polyester.
Tg is 201.5°C, based on fully aromatic polyamide <T
g was observed at 247.7°C.

The physical properties of the obtained polymer were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 The same polymerization operation as in Comparative Example 1 was carried out using the raw material composition of Example 3. Measure the physical properties of the obtained polymer,
The results shown in Table 1 were obtained.

Comparative Example 4 Using the raw material composition of Example 4, the same polymerization operation as in Comparative Example 3 was carried out to obtain a polymer.

Attempts were made to measure the physical properties of the resulting polymer, but the brittleness of the polymer made it impossible to measure elongation, tensile strength, and tensile modulus.

Example 5 57 grams of bisphenol A, 21 grams of sodium hydroxide, 5 grams of hydrosulfide and Tetra-n
- A 31 aqueous solution containing 5 grams of butylammonium bromide was charged into a reactor equipped with a stirrer, and 25.4 grams of terephthalic acid chloride and 25.4 grams of isophthalic acid chloride were dissolved in 1.51 grams of chloroform at room temperature while stirring.
A solution containing gram was added.

Thereafter, after stirring at room temperature for 7 minutes, a solution of 21 chloroform containing 51 grams of isophthalic acid chloride and m-
) 35 grams of lylene diamine and 21 grams of sodium hydroxide
21 aqueous solution containing gram was added, and stirring was continued at room temperature.

Subsequently, the reaction solution was poured into 10 N of methanol and washed with stirring. It was then dried to obtain 143 grams of white polymer. The obtained polymer was injection molded at 450°C to a thickness of 3
A disk with a diameter of 7 cm was obtained. Width 1.3 from this disk
A test piece with a length of 7 cm and a length of 7 cm was cut out in parallel and perpendicular directions to the flow direction of the resin, and the bending strength and bending elastic modulus were measured. The results are shown in Table 2.

Comparative Example 5 A polymer was obtained by carrying out the same polymerization operation as described in Comparative Example 1 using the raw material composition of Example 5 and a solvent. A disk was prepared from the obtained polymer in the same manner as in Example 5, and its physical properties in directions parallel and perpendicular to the flow direction of the resin were measured.

The results are shown in Table 2.

Comparative Example 6 As a wholly aromatic polyester, 70 parts by weight of U-polymer (manufactured by Unitika ■, trade name: U-100), which is a polymer of bisphenol A, isophthalic acid, and terephthalic acid, and Kevlar 49 (which is a wholly aromatic polyamide) were used. dupont
A pellet was prepared by melt-kneading 30 parts by weight (manufactured by Toshi Kevlar ■) at 300° C. using a twin-screw extruder.

The above pellet was molded at 300° C. to obtain a disk similar to that in Example 5, and the physical properties of this disk were measured. The second measurement result
Shown in the table.

[Effects of the Invention] The wholly aromatic polyamide polyester block copolymer of the present invention has higher toughness (
It has significantly improved physical properties such as elongation), strength, elastic modulus, and anisotropy.

Table 1 No. table

Claims (1)

[Scope of Claims] [a] All compounds obtained from at least one compound having the structure shown in formulas (i) to (iii) and at least one compound having the structure shown in formulas (iv) to (vi) Aromatic polyamide block and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼▲ Mathematical formulas, chemical formulas, There are tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R is a substituent selected from the group consisting of hydrogen, halogen, or aliphatic or aromatic hydrocarbons having 1 to 8 carbon atoms.) b] Fully aromatic polyester block obtained from at least one compound having the structure shown in formulas (i) to (iii) and a compound having the structure shown in formula (vii)▲There are mathematical formulas, chemical formulas, tables, etc.▼ ( p and q are integers of 1 to 4. X is an aliphatic, alicyclic, or aromatic hydrocarbon having 1 to 8 carbon atoms, or -S-, -SO_2-, -O-, -CO
− is. R is as described above. ) A block copolymer consisting of