JPS63277231A - Production of copolyester - Google Patents

Abstract

PURPOSE:To obtain the titled polyester, having excellent thermal stability and suitable as fibers, films, etc., by acylating a copolymerization oligomer of a liquid crystal-forming polymer, adding a specific amount of a dihydroxy compound before polymerization and carrying out the polymerization. CONSTITUTION:(A) An oligoester, obtained by reacting a dicarboxylic acid, such as terephthalic acid, with a diol, such as ethylene glycol, and expressed by formula I (R<1> is 6-20C aromatic group, etc.; R<2> is 2-40C aliphatic group, etc.) in an amount of 5-95mol.% is reacted with (B) 95-5mol.% hydroxycarboxylic acid expressed by formula II (R<3> is 6-20C aromatic group, etc.) (e.g. p-hydroxybenzoic acid) to provide a copolymerization oligomer. (C) An acylating agent (e.g. acetic anhydride) is then added and reacted therewith. (D) A dihydroxy compound expressed by formula III (R<4> is same as R<1>) (e.g. resorcin) is added to slowly decompress the reaction mixture at, e.g. 200-350 deg.C, to carry out polymerization and afford the aimed polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel method for producing a copolyester having high elastic modulus and high strength. Since the copolymerized polyester thus produced forms thermotropic liquid crystal, it can be easily molded and can be commercialized as a molding material, film, or fiber.

[Conventional technology]

In recent years, whether fibers, films or molded products,
! There is a high demand for materials with excellent 1111 properties, heat resistance, and chemical resistance. Polyester has come to be widely accepted for use in general molded products, but many polyesters have poor flexural modulus and bending strength, so high modulus and
It was not suitable for applications requiring high strength. In order to improve this mechanical property, it is known to blend reinforcing materials such as calcium carbonate and glass fiber, but this increases the specific gravity of the material, which reduces the light snacking benefits that plastics have. During molding, the molding machine is subject to severe wear and there are many practical problems.

In recent years, liquid crystalline polyester has attracted attention as a polyester that does not require a reinforcing material and is suitable for applications requiring high elastic modulus and high strength. The journals that have attracted particular attention are the Journal of Φ Polymer Science - Polymer Chemistry Editorial Edition (Vol. 7976) 20≠3 pages and the
This was after W, J, and Jakun published a thermal liquid crystal polymer composed of polyethylene terephthalate and acetoxybenzoic acid in Publication No. 6. In this work, Jackson reported that this liquid crystal polymer exhibited more than 5 times the stiffness, 3 times more strength, and 2j times more impact strength than polyethylene terephthalate, opening new possibilities for high-performance resins. Indicated.

On the other hand, we first prepared the general formula (A) -C-R凰-G-0-R2-0- (
A) [In the formula, R1 is a divalent aromatic hydrocarbon group having 6 to 2θ carbon atoms, a divalent alicyclic hydrocarbon group having 1 to 20 carbon atoms, or/and a divalent alicyclic hydrocarbon group having 1 to 20 carbon atoms. represents an aliphatic group (however, the hydrogen atom of the aromatic ring of the aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl or alkoxy group having carbon number/~μ), and R1 is a carbon number λ~≠Q divalent aliphatic hydrocarbon group, divalent alicyclic hydrocarbon group having 1 to 2Q carbon atoms, covalent aromatic hydrocarbon group having ≦ to 20 carbon atoms forming an aromatic ring (however, aromatic The hydrogen atom of the aromatic ring of the hydrocarbon group may be substituted with a halogen atom, the alkyl group with carbon number/~l may be substituted with an alkoxy group), or molecule #10-/θ
The raw material oligoester or polyester consisting of repeating units represented by
~Def Morch and general formula (B) HO-R3cooH・--
-------(B) [In the formula, R3 is a covalent aromatic group having 6 to 20 carbon atoms forming an aromatic hydrocarbon ring (however, the hydrogen atom of the aromatic hydrocarbon group is a halogen atom, Number of carbons/~
A hydroxycarboxylic acid represented by [optionally substituted with an alkyl group or an alkoxy group]? ! -j molti is reacted to make a copolymerized oligomer (first stage IPf!
”), then add an acylating agent to perform acylation (second
We have filed an application for a method for producing copolymerized polyester, which consists of three steps: step) and further polymerization under reduced pressure (third step).
Kaisho≦0-/76!2j issue, Tokukaisho 60-2 Hiro! 630
issue).

In addition, a method for increasing the polymerization rate and significantly reducing the amount of sublimate has been applied for in Japanese Patent Application No. 6O-207t1, but the copolyester produced in this way did not have sufficient thermal stability. .

[Purpose of the invention]

In view of these points, we conducted extensive research and found a method for producing a copolyester with good thermal stability.

That is, the present invention provides a method for producing a copolymerized polyester comprising the three steps described above, namely, the first step of producing a copolymerized oligomer, the second step of adding an acylating agent to perform acylation, and the third step of further polymerizing under reduced pressure. In.

Before the start of the third stage, the general formula (C)HOR40H・
......(0) (wherein R4 has the same meaning as R1 in general formula (A)) is added to form the OR''O group of (A) before the start of the third step. 1
00 equivalent, terminal OH group - terminal C0OH group Naoki ≧ 0 equivalent ...
(1) (The terminal OH group and the terminal C00H group include acylated ones) A method for producing a copolymerized polyester, characterized by reacting in the following manner.

Here, the terminal OH group means an OH group present at the terminal and an acyloxy group present at the acylated terminal, and these include HO-R~, HO-R8~, HOR4~ and their acyloxylated groups. It means something.

On the other hand, the terminal 000H group means the 0OOH group present at the terminal and the acid anhydride group (acyl ester) present at the acylated terminal, which are ~RICOOH1~RaC00
It means a compound that has been esterified with H and Hisorelanoacyl.

[Structure of the invention]

The present invention will now be described and explained in further detail.

The copolymerized polyester produced by the conventional method contains -0-R2-0-R''-C- (11
) (wherein R2 and R3 have the same meanings as R2 and R3 in formulas (A) and (B)).
The balance between the group and the 1000H group is lost, and the -0OOH group end is in excess. Therefore, in addition to OH groups, C0OH groups in the copolymer may react with the acylating agent to form acid anhydride bonds, or terminal carboxylic acids may remain in the final copolymerized polyester. It is thought that the polymerized polyester has become unstable to heat.

Therefore, in the present invention, the excess -COOH group is eliminated by adding a dihydroxy compound represented by the general formula (C) equivalent to or more than 1000H groups,
After that, it is possible to produce a copolymerized polyester with excellent thermal stability by carrying out the λ-stage acylation or adding a dihydroxy compound while performing the acylation, and carrying out a condensation reaction under reduced pressure.

The present invention is particularly carried out by reacting the polyester or oligoester represented by the general formula (A) with oxycarbon to form a copolymerized oligomer, followed by acylation and further polymerization under reduced pressure. To explain in more detail, the polyester te represented by the general formula (A) is used to produce an oligoester, so K is the dicarboxylic acid aoocRlcoam represented by the general formula (E).
--(E) (In the formula, R1 has the same meaning as in general formula (A)) Oyobis ester is used, but examples of carboxylic acids include terephthalic acid, methoxyterephthalate, ethyl 7
Terephthalic acid, fluoroterephthalic acid, chloroterephthalic acid, methylterephthalic acid, isophthalic acid, heptalic acid,
Methoxyisophthal H, diphenylmethane≠, r-dicarboxylic acid, diphenylmethane 3,31-dicarboxylic acid,
Diphenyl ether, ≠'-dicarboxylic acid, diphenyl-dicarboxylic acid, naphthalene, 21g-dicarboxylic acid, naphthalene/,! Dicarboxylic acid, naphthalene 1,4 dicarboxylic acid, adipic acid, sepacic acid, azelaic acid, speric acid, dodecanedicarboxylic acid, 3-
Methyl azelaic acid, glitaric acid, succinic acid, cyclohexane 1,4 dicarboxylic acid, cuclohexane/, 3 dicarboxylic acid, cyclobe/than/,! Examples include dicarboxylic acids. These may be used in combination with the general formula (
K) can be used.

In addition, the general formula (
Specific examples of the diol HOR"OR-・Yamakawa-(F) (in the formula, HN has the same meaning as in general formula (A)) represented by F) include ethylene glycol, /, 3-propanediol, /, 2- Propanediol, /, 3-butanediol% /, 41.-Butanediol, neopentyl glycol, /, 6hexanediol, /μ coco-decanediol, cyclohexane/, 41-diol, cyclohexane l, 3diol, cyclohexane/ , 2-diol, cyclobenpentane!, !-diol, diethylene glycol, polyethylene glycol, hydroquinone,
Examples include resorcinol, bisphenol A1 methylhydroquinone, chlorohydroquinone, and 6-naphthalene diol, but these may be used in combination, and any of those represented by general formula (F) can be used.

Regarding the polyester represented by the formula (A) used in the present invention, any oligoester represented by the general formula (A) can be used, but polyethylene terephthalate, polybutylene terephthalate and Those oligomers are preferred, especially polyethylene terephthalate and its oligomers.

Examples of the hydroxycarboxylic acid of formula (B) include parahydroxybenzoic acid, ≠-hydroxy 3-chlorobenzoic acid, metahydroxybenzoic acid, ≠-hydroxy J, j-dimethylbenzoic acid, cooxy-naphthoic acid, and! -oxyj-
Examples include naphthoic acid, /-hydroxy-hiro-naphthoic acid, Schlinger's acid, vanillic acid, and hiro-hydroxy-3-methylbenzoic acid. Although it is preferable to use rose hydroxybenzoic acid # alone in order to maintain melt anisotropy, any hydroxycarboxylic acid represented by the general formula (B) can be used, or a mixture of these can be used. I don't mind.

In addition, the reaction between the hydroxycarboxylic acid (B), the polyester represented by the general formula (A), and the oligoester is 20
The reaction is carried out at 0 to 350°C, preferably 220 to 3Qθ°C! minutes ~/θ hours, preferably 20 minutes ~! It is done in a timely manner.

In the reaction, the residual amount of the hydroxycarboxylic acid compound is usually 70 mole or less based on the amount charged, preferably! This is carried out until it reaches θ molti or less, particularly preferably 4LO molti or less.

! Although the above reaction can be carried out without a catalyst, it can be carried out with the addition of a catalyst if necessary.

As the dihydroxy compound (C) used in the present invention, any compound represented by the general formula (0) can be used, but specific examples include hydroquinone, resorcinol, methylhydroquinone, chlorohydroquinone, t-butylhydroquinone, ．． j di-t-butylhydroquinone,
Ko, Hiroshi, itrimethylresorcinol, naphthohydroquinone, ≠, μ′ biphenol, acetoxyhydroquinone, nitrohydroquinone, dimethylaminohydroquinone, 1,4-dihydroxnaphthol, /, j-dihydroxynaphthol, /, 6-dihydroxynaphthol,
Co, ≦-dihydroxynaphthol, Co, 7-dihydroquiknaphthol, 2,2'-bis(Hiro-hydroxyphenyl)furopane, 2,2'-bis(4t-hydroxy-
J, s-dimethylphenyl)furopane 1.2.2'-bis(sen-hydroxy3.j-dichlorophenyl)-propane, 2.2'-bis(≠-hydroxy-3-methylphenyl)-propane, 2.2 '-Bis(4L-hydroxy-3-chlorophenyl)propane, bis(Hiro-hydroxyphenyl)-methane, bis(4A-hydroxy-3
,5-dimethylphenyl)-methane, bis(4=-hydroxy-3,j-dichlorophenyl)-meta/, bis(
I/--hydroxy-3,j-dibromophenyl)-methane, /,/-bis(4t-hydroxyphenyl)cyclohexane, tx,,4! ,'-dihydroxydiphenylbis(≠-hydroxyphenyl)-ketone, bis(≠
-Hydroxy 3. ! -dimethylphenyl)-ketone,
Bis(Hiro-hydroxy-3,J--dichlorophenyl)
-ketone, bis(≠-hydroxyphenyl) sulfide, bis(4-hydroxy-3-chlorophenyl) sulfide, bis(4t-hydroxyphenyl)sulfone, bis(4L-hydroxy-3,s-dichlorophenyl)
Ether, etc. are mentioned.

The compound represented by the general formula (C) may be added at any time before the start of the third stage, but it is particularly preferably added after the first stage reaction is completed.

The amount of the compound represented by the general formula (0) in the reaction mixture before the start of the third step is (1) terminal OH group equivalent - terminal 000F1 group equivalent relative to oRtO residue/θ0 equivalent of (A) ≧0 equivalents (the terminal OH group and the terminal COOH group are acylated, including nine), preferably in such a manner that (i) is equal to or more than J equivalent and equal to or less than HiroO equivalent.

If the amount exceeds 100%, the thermal stability is good, but the polymerization rate slows down, which is undesirable.

The amount of terminal groups can be determined by analyzing the reaction solution at the start of the third step.
It is possible to understand this in advance.

The terminal group can be measured using E-NMR in a solvent such as DMSO.

For example, the * proton in * ho o c o o ~ is 6. t
r j ppm* HO (H, aFizO~ The * proton of 02 ppm acid can be used to determine the concentration of the necessary terminal group by methyl esterification, etc.).

On the other hand, measurement of the terminal group of (A) used and generation (
D) -0-R2-0-R3-C! - From the measurement of terminal terminal OH group - terminal GOOH group (0 equivalent), it is not preferable to add a roxy compound because it has adverse effects such as a decrease in the polymerization rate and the occurrence of sublimation.

As for the addition method, it may be added in bulk, or it may be diluted with a diluent and added.

It is also preferable to use two or more types of (C) in that the physical properties can be controlled. For example, when combined with hydroquinone and Hiroj'-bisphenol, which increase liquid crystallinity, and resorcinol, co-, and 2'-bis(≠-hydroxyphenyl)fluorocarbons, which reduce liquid crystallinity, the raw materials (A) and (
It is possible to obtain desired physical property values without changing the composition of B).

Addition of (C)'! There is no particular restriction on the amount of (B) as long as it is selected to meet the above conditions, but usually the amount of /~! This is Q Morchi.

The second step, acylation, uses an acylating agent (acylating agent).
/((B) +2 (C) ), Q, 5 times the mole or more, 2
It is carried out using 90 times the mole or less, preferably 0.7 times the mole or more/j times the mole or less, and in that case, the dropping time of the acylating agent is arbitrary, but desirably 70 minutes or more, preferably 20 minutes. The above will be implemented. Contact with acylating agent is 20
It is preferably carried out at a temperature of ℃ to 3 θ℃! θ℃〜200℃
, more preferably at rθ°C//θ°C, and may be under pressure.

Alternatively, acylation may be carried out by lowering the temperature of the system to a temperature below the boiling point of the acylating agent. The reaction is carried out within 5 hours, preferably in the range of 10 minutes or more to 3 hours.

The diol of general formula (C) may be added before this acylation is completed.

In addition, acylating agents include acetic anhydride, propionic anhydride,
Although butyric anhydride, benzoic anhydride, etc. are used, any commonly usable acylating agent can be used, and among them, acetic anhydride is representative from the viewpoint of reactivity and cost.

Next, the third stage of polymerization ld, 200°C to 3JO'C.

It is preferably carried out at a temperature of 2.20°C to 330°C, but in this case it is preferable to gradually reduce the pressure at an initial temperature of 760r
The time required to gradually reduce the pressure from ttxHy to /mHyi is rd3o minutes or more, preferably 60 minutes or more, especially from /θwnHy1 minute/ [Hy 7
It is important to perform the depressurization gradually.

The second and third stages can also be carried out without a catalyst, but may be carried out in the presence of a catalyst if necessary.

Catalysts used in the first, second and third stages include transesterification catalysts, polycondensation catalysts, acylation catalysts,
Decarboxylation catalysts are used, and these may be used in mixtures.

The amount used is relative to the polymer! ~! θ, 000ppm
Preferably it is j O to j 000 ppm.

In addition, ηinh is phenol and tetrachloroethane/ or more, preferably 0. J! dt/ is above.

The copolymerized polyester thus produced has a terminal C
Since there are more terminal -OH groups and their acyloxy groups than 0OH groups, it has the advantage of excellent hot water resistance and hydrolysis resistance.

〔Example〕

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to the following examples.

Example/ A glass polymerization tube equipped with a stirring blade, a nitrogen inlet, and a pressure reduction port was
-Hydroxybenzoic acid! /, J”? (0,371 mol), polyethylene tere-7-thalerate oligor −(η
1nh=0.09Fdt/f) 72. /2 (0.37 j mol as repeating unit amount), stannous acetate 0,
037t was charged, vacuum and nitrogen substitution was repeated three times,
Finally, it is filled with nitrogen and placed under a nitrogen flow with a flow rate of θ,j of 1.7M. When the polymerization tube is immersed in an oil bath at 24Lθ℃, the contents will melt in about 30 minutes, so start stirring,
A copolymerized oligomer is produced by performing co-transesterification as it is.

After that, the temperature dropped in about 3Q minutes to /≠Q'C, and the hydroquinone f? , 25? (0,075 mol) and then acetic anhydride 57? (07≦57 mol) was added dropwise over 30 minutes, and the mixture was stirred for a further 7 hours, followed by acylation. After that, the temperature of the oil bath was raised to 273T:, over 2 hours, and zinc acetate dihydrate θ, Oj ? t and gradually apply vacuum. Then, after reaching a high vacuum of Oi mm Hy, polymerization was carried out for 3 hours. The product was taken out by breaking the glass polymerization tube and made into chips, and then air-dried overnight at 3θ°C. The obtained polymer is milky white and opaque, and ηi
nh = 0.70.

This polymer was further open-dried at 120°C for 130°C.
The thermal stability was excellent, with ηinh = 0°7Q even after repeated tests.

Also, the results of Engineering R showed that there was no acid anhydride bond at all.

In this system, NMR analysis shows that 10
0 equivalent 100) (rich CI'!, terminal O to O- group
H group! 7.6 equivalent terminal C0OH group J O,! Equivalent (all including acetylated groups), terminal OH group - terminal COOH group = 26°r equivalent, 9.

In addition, the terminal OH group of the charged polyethylene terephthalate oligomer is 2 per 100H, OH, O- group of /θθ equivalent.
There are 0 equivalents, the terminal C0OH group is 72 equivalents, and the generated ether component is 700
The 01'I group of the added hydroquinone is // equivalent to the equivalent 10CR, CH20- group, and the 01'I group of the added hydroquinone is ≠θ equivalent to the /θθ equivalent 0CR1CH20- group, so the third
The terminal OR group-terminal Coo:FI group before the start of the step was (2o-(//X2) Tohiro θ)-/2=26, which was consistent with the above result.

The terminals of this copolymerized polyester are polyester/, 062, and the OH terminal groups are substantially O equivalent o c OH, and the terminal groups are /2 equivalent to C! The OOE end groups were ≦6 equivalents, and the ends of the copolyester were rich in OII groups (including acetylated ones).

Example Co. Stir PR% Nitrogen introduction b, p into a glass polymerization tube equipped with a decompression port
-Hydroxybenzoic acid 62,2 f (0,41 j mol) Polyethylene terephthalate oligomer (ηinh
= 0,0ri/dl/l) j 7,7 f (0
, 30 mo/L/) stannous acetate θ, θJtf,
Repeat depressurization and nitrogen substitution three times, and finally add nitrogen dropwise.
Place under nitrogen flow at a flow rate of 0,j1/11riR. When the polymerization tube is immersed in a 2/O'C oil bath, the contents will melt in about 30 minutes, so stirring is started and transesterification is carried out for 2 hours to produce a copolymerized oligomer. After that, take noidoquinone/,,2! S'(0°075
mol) and then acetic anhydride/22. Hirof1f: J 0
Add it dropwise over a few minutes and continue stirring for another 7 hours.
Perform acylation. Then set the temperature of the oil bath to J7j'
The temperature was raised to C over 1 hour, and zinc acetate dihydrate 0.04
/t and gradually apply vacuum. and θ, J
Polymerization was carried out for 2 hours after the high vacuum of ttxHf was established. ηinh of the obtained polymer = 0. / It was 7. This poly i- is further open-dried at 720°C,
Even after 30 hours, ηinh = 0.1''j, showing excellent thermal stability.

From the results of Engineering R, we are confident that there is no acid anhydride bond at all.

In this system, as a result of NMR analysis, 1
00 equivalent of 100H, C1 (, terminal OH to O- group
Group J /, 44 equivalents Terminal CooH group 32゜j equivalents (all including acetylated groups) Terminal OH group - Terminal C0OH group = j, ? The amount was equivalent.

Also, the terminal O of the charged polyethylene terephthalate oligomer
H group, terminal C! The OOH group, the generated ether component, and the hydroquinone were 700 equivalents of 10 CI (20 equivalents, /2 equivalents, 26 equivalents, and -25 equivalents, respectively, per 1 CH20- group).
Since this is the current situation, the terminal OH group-terminal 000H group before the start of the third stage is [θ-(2≦X2)+(KO5×2))−/J=4, which is consistent with the result on υ.

Comparative Example: The same procedure as in Example 1 was carried out except that hydroquinone was added.

ηinh of the produced polymer was 0.7/.

However, when this polymer was oven dried at 120°C for 72 hours, ηinh = 0. j j and decreased significantly.

From the results of 1, the acid anhydride bond is approximately /
Q% exists.9.

In this case, OH group-〇〇〇FK group before the start of the third stage = (,2a-(,zgx2))
-t2=-+Hiroshi〈Q.

Example 3 Hydroquinone of Example/? , 2 Jr t instead of hydroquinone ≠, /λ! f Hiroshi Ruzorsin, / j J
The same procedure as in Example 1 was carried out except that "t" was used.

ηinh of the nine polymers obtained = 0.60, /2
θ℃2= Even after 730 hours of bun drying, η1nh=0. s
It was 9.

Moreover, the IR results showed that there was no sialic acid anhydride bond at all.

The difference (equivalent) between the terminal OH group and the terminal 000H group was the same as in Example.

Comparative Example 2 The same procedure as in Example 2 was carried out except that 0.03θ mole of hydroquinone*t was added.

The resulting polymer had ηinh = 0°7S, and acid anhydride bonds existed in an amount of about 5% relative to ester bonds. / After 730 hours of oven drying at -0°C, r!
inh = o, decreased to ≦7.

In this case, ioo 100H! The terminal OI of the raw material with respect to the OH, O- group (the group is 20 equivalents, the terminal ccioa group is /
2 equivalents, and since there are 2≦amounts of ether bonds, OH group - 000H group = (2θ - (2 x 2) + (10 x
ko))-/, 2=-2hiro〈θ.

Example ≠ Polyethylene terephthalate oligomer 2 r, t
? (0,t, r mol), p-hydroxybenzoic acid r
, 2tt < 0.50 mol), hydroquinone was added at t3t (θ, (7j 7 j mol), and the amount of acetic anhydride was added!≠, 2 f (0,? 3 mol). All steps except 9 were carried out. It was done in the same way as Example/.

The obtained polymer had ηinh=0.9/.

No acid anhydride bond was observed by RGC.

-QC of 10θ equivalent! H, CIII, terminal OH group co θ equivalent of polyester oligomer with respect to O- group, terminal co
On group 72 base weight 2 equivalent Ter component is ko! Since the amount is large, terminal OR group - terminal C0OH group = (so-(2,, rxx) + (, zjxz)'j-y
x=+r equivalent.

Example! Polyester polymer (ηinh = 0.6
/ ) ft, add hydroquinone at a temperature of 270°C to make the first stage oligomer /r, /ry (
79.2t (0.0,t≦5mol) of acetic anhydride was added.
The same procedure as in Example 1 was carried out except that 776 mol) was added.

The obtained polymer had ηinh = θ, 7, and even when this polymer was further dried in an oven at 720° C. for 730 hours, it had excellent thermal stability with ηinh = 0.72.

Furthermore, the results of Engineering R showed that there was no acid anhydride bond at all.

In this system, NMR analysis shows that 70
θThe terminal OH group for one 0CR, CH, O- group in the current view
1I-3゜2 The terminal C0OH group at 22.3 equivalents (all including acetylated groups), and terminal OH group - terminal 000H group = ≠ equivalent to λ. Example 6 Hydroquinone was prepared from the beginning. Example/ except for the addition of
I did the same thing.

The obtained polymer had ηinh=0.72.

The difference (equivalent) between the terminal OH group and the terminal CooH group was the same as in Example.

〔Effect of the invention〕

As described above, according to the water layer invention method, a copolymerized polyester having excellent thermal stability can be obtained.

Sender: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - Others/Names

Claims (7)

[Claims] (1) General formula (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼……(A) [In the formula, R^1 is a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and 4 to 20 carbon atoms. 20 divalent alicyclic hydrocarbon groups or/
and a divalent aliphatic hydrocarbon group having 1 to 40 carbon atoms (however, the hydrogen atom of the aromatic ring of the aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl or alkoxy group having 1 to 4 carbon atoms) ), R^2 is a divalent aliphatic hydrocarbon group having 2 to 40 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, and 6 to 20 carbon atoms forming an aromatic ring. is 2
valent aromatic hydrocarbon group (however, the hydrogen atom of the aromatic ring of the aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group), or a polyamide with a molecular weight of 80 to 8000. [representing an alkylene oxide divalent radical] The raw material oligoester or polyester consists of a repeating unit represented by the formula (B) HO-R^3COOH... ...(B) [In the formula, R^3 is a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms forming an aromatic ring (however, the hydrogen atom of the aromatic hydrocarbon group is a halogen atom, A copolymerized oligomer is produced by reacting 95 to 5 mol % of a hydroxycarboxylic acid represented by ~4 (optionally substituted with an alkyl group or an alkoxy group) (first step), and then an acylating agent is added to form a copolymerized oligomer. In a reaction consisting of three steps, acylation is carried out (second stage) and polymerization is further carried out under reduced pressure (third stage).
Before the start of the step, a dihydroxy compound represented by the general formula (C) Before starting the third step, terminal OH group equivalent - terminal COOH group equivalent ≧ 0 equivalent for 100 equivalents of OR^2O group in (A)... (I
) (herein, the terminal OH group and the terminal COOH group include those that are acylated). (2) A method for producing a copolyester according to claim 1, in which the terminal OH group equivalent - the terminal COOH group equivalent ≧ +5 equivalents in formula (I) (3) In formula (A), 60% or more of R^1 is 1,4-
The manufacturing method according to claim 1, which is a phenylene group. (4) The manufacturing method according to claim 1, wherein in formula (A), R^2 is an aliphatic hydrocarbon group having 2 to 6 carbon atoms. (5) The manufacturing method according to claim 1, wherein R^1 in formula (A) is a 1,4 phenylene group. (6) The manufacturing method according to claim 1, wherein in formula (A), R^2 is an aliphatic hydrocarbon group having 2 carbon atoms. (7) The manufacturing method according to claim 1, wherein in formula (B), R^3 is a 1,4 phenylene group