JPH0461012B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new copolymerized polyester with a high modulus of elasticity and high strength. Furthermore, it forms a thermotropic liquid crystal, so it is easy to mold and can be commercialized as a molding material, film, or fiber. It concerns polyester. In recent years, there has been an increasing demand for materials with excellent rigidity, heat resistance, and chemical resistance, whether fibers, films, or molded products. Polyester has come to be widely accepted for use in general molded products, but many polyesters have poor mechanical properties such as flexural modulus, so they are not suitable for applications that require 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 lightweight advantage of plastic. During molding, the molding machine is subject to severe wear, which causes many practical problems. In recent years, polyester has been used as a material that does not require reinforcement and is suitable for applications that require high strength.
Liquid crystalline polyester has started to attract attention.
Particularly noteworthy was the Journal of Polymer Science Polymer Chemistry Edition, Volume 14 (1976) 2043.
This was after W.J. Jackson published a thermal liquid crystal polymer consisting of polyethylene terephthalate and acetoxybenzoic acid in pages 1 and 18016/1983. Among these, Jackson claims that this liquid crystal polymer has a rigidity more than five times that of polyethylene terephthalate.
It was reported that it exhibited more than 4 times the strength and 25 times more impact strength, demonstrating new possibilities for high-performance resins. However, this liquid crystalline copolyester contains infusible particles (heterogeneous polymer) in addition to the copolyester, has a high Tm of 210 to 220°C, and also investigated the relationship between melt viscosity and shear rate. In this case, it has a large temperature dependence and cannot be stably molded, and the yarn obtained by extruding this polymer has disadvantages such as low ultimate elongation. In view of these points, the present inventors conducted intensive studies and found that there were no different types of polymers, and as a result of investigating the relationship between melt viscosity and shear rate, the temperature dependence was small, and it was found that the formation temperature was low. The present invention was achieved by discovering a polymer that can be stably molded even under changes. The mechanical properties of the molded products made of the copolyester of the present invention are not inferior to those of the conventional copolyester mentioned above, and the molded products have less anisotropy in mechanical strength, and have high rigidity and high It has strength. The gist of the present invention is a dicarboxylic acid unit represented by general formula (A), (In the formula, at least 60 mol% or more of R ¹ is 1,
4-phenylene group, and 40 mol% or less is 1,4
- C ₆ to _{C 16} divalent aromatic hydrocarbon group other than phenylene group, C ₄ to _{C 20} divalent alicyclic hydrocarbon group, or C ₁ to C ₄₀ divalent aliphatic hydrocarbon group shows.
However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (including 1,4-phenylene group) may be substituted with a halogen atom, a C ₁ to C ₄ alkyl group, or an alkoxy group) General formula ( Glycol unit represented by B) -O- ^R2 -O-...(B) (wherein, ^R2 is a _C1 to _C20 divalent aliphatic hydrocarbon group or a _C4 to _C20 divalent aliphatic hydrocarbon group) (represents an alicyclic hydrocarbon group) and an oxycarboxylic acid unit represented by the general formula (C) (In the formula, at least 60 mol% or more of R ³ is 1,
4-phenylene group, and 40 mol% or less is 1,4
- Indicates a C ₆ to C ₁₆ divalent aromatic hydrocarbon group other than a phenylene group. However, aromatic hydrocarbon groups (1,
The hydrogen atom of the benzene ring (including the ₄ -phenylene group) may be substituted with a halogen atom, a C1- _C4 alkyl group, or an alkoxy group), but one of the oxycarboxylic acid units (C) is combined with a part of the glycol unit (B) through an ether bond to form the general formula (D). (In the formula, R ² and R ³ are in formulas (B) and (C)
The content of ^dicarboxylic acid unit ( ^A ) is 10 to 40 mol%, and the content of dicarboxylic acid unit (A) and oxycarboxylic acid unit is 10 to 40 mol%. The ratio (C)/(A)+(C) of oxycarboxylic acid unit (C) to the total amount of (C) is 30 to 80 mol%, and the ratio of glycol unit (B) and oxycarboxylic acid unit (C) is 30 to 80 mol%. The ratio (C)/(B) + (C) of the oxycarboxylic acid unit (C) to the total amount is 30 to 80 mol%, and the ratio (D)/(B) of the unit (D) to the glycol unit (B) is 30 to 80 mol%. ) is 3 to 20 mol%, the ratio (molar ratio) of unit (B) to unit (A) is 1≦(B)/(A)≦1.1, and the ratio of phenol to tetrachloroethane is 1:1 ( A copolymerized polyester having a logarithmic viscosity ηinh of 0.4dl/g or more when measured at 30°C at a concentration of 0.5g/dl in a mixed solution (weight ratio), and the copolymerized polyester has the general formula (E) Raw material polyester or oligoester consisting of the repeating unit represented by (In the formula, R ¹ and R ² are the general formula (A) and
R ¹ and R ² in (B) have the same meanings) An oxycarboxylic acid represented by the general formula (H) and HO−R ³ COOH...(H) (wherein, R ^{3 is R 3 in} the general formula shown above) ) is reacted to form a copolymerized oligomer, an acetylating agent is added to carry out acetylation and polymerization, and the reaction is then completed under reduced pressure. It consists of copolymerized polyester. To explain the present invention in detail, the first characteristic of the copolyester of the present invention is that it was measured by DSC.
In terms of the relationship between Tm and composition, the structure is such that when (C)/(B)+(C) changes from 65 mol% to 35 mol%, Tm changes by 15°C or more. Unit (C)
The remarkable decrease in Tm with increasing amount of introduced unit (C) is considered to indicate that unit (C) is uniformly dispersed in the polymer chain. In other words, when the unit (C) is not uniformly introduced into the polymer chain but enters in blocks (for example, in the case of the comparative example), the polymer chain and structure are not so disordered because the liquid crystal unit is relatively long. However, if the unit (C) is uniformly introduced into the polymer chain, the length of the liquid crystal unit is short and the polymer chain and structure are extremely disordered, so the Tm decrease is small. This is because it is thought that it will become a big thing. The change in Tm when (C)/(B)+(C) changes from 65 mol% to 35 mol% is 15°C or higher, preferably 25°C or higher, particularly preferably 35°C or higher. If the change in Tm is less than 15°C, as shown in the comparative example, the mechanical anisotropy of the copolyester becomes large, which is not preferable. The second feature of the copolyester of the present invention is that the content of unit (D) in the ratio (D)/(B) is 3 to 20 mol%, particularly preferably 5 to 18 mol%. It is preferable to set it within such a range in order to increase the elastic modulus of the copolymer and reduce mechanical anisotropy. The content of units (A) derived from dicarboxylic acids or derivatives thereof is 10 to 40 mol%, preferably 15
~40 mol%. The relationship between unit (A) and glycol unit (B) (means all units derived from glycol. Therefore, the glycol unit included in unit (D) is also included) is the same as for unit (A). The ratio (molar ratio) of unit (B) is 1≦(B)/(A)≦1.1
Make it so that Based on the total amount of glycol unit (B) and oxycarboxylic acid unit (C) (means all units derived from oxycarboxylic acid. Therefore, the oxycarboxylic acid unit contained in the above unit (D) is also included). The ratio of unit (C) (C) / (B) + (C) is 30 ~
80 mol%, preferably 35 to 70 mol%. The ratio (C)/(A)+(C) of oxycarboxylic acid unit (C) to the total amount of dicarboxylic acid unit (A) and oxycarboxylic acid unit (C) is 30 to 80 mol%, preferably 35 to 70 mol %. R ¹ , R ² and R ³ in general formulas (A), (B), (C) and (D) are examples of compounds represented by general formulas (F), (G) and (H) below. Those mentioned above are also exemplified. Particularly preferably, R ¹
And as R ³ , 60 mol% or more is 1,4 phenylene group and 40 mol% or less is 1,3- or 1,
2-phenylene group or naphthylene group (however, the hydrogen atom of the benzene ring of the phenylene group or naphthylene group is a halogen atom, and has 1 to 4 carbon atoms (C ₁ to _{C 4} )
(optionally substituted with an alkyl group or an alkoxy group) or all are 1,4-phenylene groups. As R ² ,
An aliphatic hydrocarbon group having 6 or less carbon atoms (C ₆ or less), particularly an ethylene group, is preferred. The copolymerized polyester of the present invention is contained in a mixed solution of phenol and tetrachloroethane at a ratio of 1:1 (weight ratio).
The logarithmic viscosity ηinh measured at 30℃ at a concentration of 0.5g/dl is
It is 0.4 dl/g or more, preferably 0.5 dl/g to 1.5 dl/g. Therefore, the copolyester of the present invention can be produced by contact-reacting a polyester or oligoester with an oxycarboxylic acid to form a copolymer oligomer, followed by acetylation and polymerization, and then deacetic acid. can. To explain the manufacturing method in more detail, the method for manufacturing copolymerized polyester generally involves using a raw material polyester or oligoester represented by the general formula (E). (In the formula, R ¹ and R ² are the general formula (A) and
The same meanings as R ¹ and R ² in (B) are used, but such raw material polyester (E)
In order to produce HOOCR'COOH...(F), a carboxylic acid represented by the general formula (F) and its ester are used. Examples of carboxylic acids include terephthalic acid, methoxyterephthalic acid, ethoxyterephthalic acid, fluoroterephthalic acid, chloroterephthalic acid, methylterephthalic acid, isophthalic acid, phthalic acid, methoxyisophthalic acid, diphenylmethane 4,4'-dicarboxylic acid,
Diphenylmethane 3,3'-dicarboxylic acid, diphenyl ether 4,4'-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, naphthalene-2,6-
dicarboxylic acid, naphthalene 1,5 dicarboxylic acid,
Naphthalene 1,4 dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, suberic acid, dodecane dicarboxylic acid, 3-methyl azelaic acid, glitaric acid, succinic acid, cyclohexane 1,4 dicarboxylic acid, cyclohexane 1,3 dicarboxylic acid, cyclo Examples include pentane 1,3 dicarboxylic acid. These may be used as a mixture, and any of those represented by the general formula (F) can be used. Specific examples of the diol HOR ² OH... (G) represented by the general formula (G) used to produce (E) include ethylene glycol, 1,3-
Propanediol, 1,2-propanediol,
1,3 butanediol, 1,4-butanediol, neopentyl glycol, 1,6hexanediol, 1,12-dodecanediol, cyclohexane 1,4diol, cyclohexane 1,3diol, cyclohexane 1,2-diol, cyclo Examples include penpentane 1,3-diol, but these may be used in combination, and any of those represented by general formula (G) can be used. As the polyester or oligoester represented by the formula (E) used in the present invention, any of those represented by the general formula (E) can be used, but due to their easy availability, polyethylene terephthalate, polybutylene terephthalate, Oligomers are preferred, particularly polyethylene terephthalate and its oligomers. Next, to describe the reaction method, the raw material polyester or oligoester represented by the general formula (E) and the oxycarboxylic acid represented by the general formula (H) and HO−R ³ COOH … (H) (in the formula, R ³ is It has the same meaning as R ³ in the general formula (C)) and is heated at 150 to 350°C under normal pressure to form a copolymerized oligomer, and then an acetylating agent is added to perform acetylation and polymerization, followed by depressurization. Below, the reaction is further carried out by deaceticating under vacuum to complete the reaction. It is also possible to share (G) and (F) when bringing them into contact with (E) and (H). As the oxyacid represented by the general formula (H), parahydroxybenzoic acid, 4-hydroxy3-chlorobenzoic acid, metahydroxybenzoic acid, 4-hydroxy3,5-dimethylbenzoic acid, 2-oxy6-
Examples include naphthoic acid, 1-oxy-5-naphthoic acid, 1-hydroxy-4-naphthoic acid, Schulinger's acid, vanillic acid, and 4-hydroxy-3-methylbenzoic acid. Although it is preferable to use parahydroxybenzoic acid alone in order to maintain melt anisotropy, any oxycarboxylic acid represented by the general formula (H) can be used. The amount of oxycanebonic acid used is (H)/(E)+
(H), (H)/(E)+(F)+(H), (H)/(E)+(
G)+
(H) or (H)/(E)+(F)+(G)+(H)
It is 30-80 mol%. Further, acetic anhydride is typically used as an acetylating agent, but the acetylating agent is not necessarily limited thereto. Furthermore, if necessary, a transesterification catalyst, an acetylation catalyst, and a polymerization catalyst may be used. Furthermore, the copolymerized polyester according to the present invention is
Depending on various purposes, small amounts of copolymerization components can also be introduced. The copolymerized polyester obtained in this way has a relatively low melting point (Tm) measured by DSC, which varies greatly depending on the composition, so Tm can be easily controlled (i.e., Tm and composition ratio (C)/(B)). +
(C) has a relationship as shown in Figure 1).
Furthermore, since the temperature dependence of the melt viscosity is small, it is suitable for stable molding. For example, when (C)/(B) + (C) in the polymer is 60 to 35 mol%, for example, when using a method such as Comparative Example 1, the dependence of melt viscosity on shear rate at low shear rates is large, and when the temperature is increased, a region where the shear rate is around 10 ³ /sec appears where the melt viscosity does not depend on the shear rate, and the temperature dependence of the melt viscosity is large. On the other hand, in the polymer according to the present invention, the dependence of the melt viscosity on the shear rate is small at low shear rates, and as the shear rate increases, the dependence of the melt viscosity on the shear rate also increases. Furthermore, this tendency does not change even if the temperature is increased, and the temperature dependence of melt viscosity is generally small. Furthermore, the polymer obtained by the present invention has a considerably larger ultimate elongation than liquid crystal polymers obtained by conventional methods, and has a linear expansion coefficient of the same order (10 ^-6 /℃) as conventional polymers. The shrinkage rate also remains unchanged. Furthermore, resins other than liquid crystal polymers generally have linear expansion coefficients of 10 ^-4 to ^{10 -5} /°C, and it can be seen that the polymer of the present invention has very well-balanced physical properties even when used as a thread. As described above, the copolyester of the present invention is useful as an extrusion molding material. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, DSC (Differential Scan-
Measurement of Tm using a PerkinElmer DSC-type was carried out by heating the sample to 338°C (20°C/min), holding it for 5 minutes, and then increasing the temperature to 16°C at a rate of 20°C/min. The melting temperature of the crystalline portion was determined when the temperature was raised at a rate of 20°C/min. Further, the shear rate γ was measured by a conventional method using a Koka-type Flow Dester. Furthermore, the logarithmic viscosity (ηinh) in a mixed liquid of phenol:tetrachloroethane=1:1 (weight ratio)
Measured at 0.5g/dl (30°C). Example 1 38.4 g (0.2 mol) of polyethylene terephthalate oligomer (ηinh0.10 dl/g) was mixed with 41.4 g (0.3 mol) of parahydroxybenzoic acid and stannous acetate.
After putting 0.024 g into a polymerization tube equipped with a stirrer and purging with nitrogen three times, the polymerization tube was placed in an oil bath at 240°C and stirred for 1 hour under a nitrogen stream. Then acetic anhydride
30.6g (0.3mol) was added and stirred for 1 hour and 30 minutes.
While acetic acid was being distilled out, the bath temperature was then raised to 275°C, and the acetic acid was completely distilled out under a vacuum of 5 Torr. Furthermore, the polymerization tube was returned to normal pressure with nitrogen, and after adding 0.044 g of zinc acetate dihydrate, it was placed under a vacuum of 0.2 Torr.
The polymerization was completed by stirring for an hour. The polymer had an ηinh of 0.70 dl/g. Furthermore, when this polymer was analyzed using JEOL's 100MHs NMR using trifluoroacetic acid as a catalyst, τ
=5.04 and

Proton of β methylene in [formula], τ = 5.44

Proton of α methylene in [formula], τ = 2.52

α proton of benzene ring in [formula], τ = 1.52

β proton of benzene ring in [formula], τ = 1.74

The proton of the benzene ring of [Formula] was absorbed. Table 1 shows the content of each unit determined from these results. Further, Tm was 193°C, and ΔHm determined from the endothermic peak in that case was 2.4 cal/g. Example 2 Polyethylene terephthalate oligomer (ηinh
The same reaction as in Example 1 was carried out except that 48.0 g (0.25 mol) of parahydroxybenzoic acid (=0.10 dl/g) and 34.5 g (0.25 mol) of parahydroxybenzoic acid were used. As a result, ηinh=
0.60 dl/g of polymer was obtained. Table 1 shows the expansion unit content, Tm, and ΔHm of this polymer determined in the same manner as in Example 1. Example 3 Polyethylene terephthalate oligomer (ηinh
The same reaction as in Example 1 was carried out except that 57.6 g (0.30 mol) of parahydroxybenzoic acid (=0.10 dl/g) and 27.6 g (0.20 mol) of parahydroxybenzoic acid were used. As a result, ηinh
=0.43 dl/g of polymer was obtained. It was also determined in the same manner as in Example 1. Table 1 shows the measurement results for each unit content, Tm, and ΔHm. Furthermore, the temperature dependence of the melt viscosity and shear rate of the obtained polymer is shown in Figure 2. Example 4 Polyethylene terephthalate oligomer (ηinh
The same reaction as in Example 1 was carried out except that 19.2 g (0.10 mol) of parahydroxybenzoic acid (=0.10 dl/g) and 55.2 g (0.40 mol) of parahydroxybenzoic acid were used. As a result, ηinh=
A polymer with a concentration of 0.82 dl/g was obtained. Table 1 shows the content of each unit in the polymer and the measurement results of Tm and ΔHm determined by the same method as in Example 1. Example 5 Polyethylene terephthalate oligomer (ηinh
The same reaction as in Example 1 was carried out except that 28.8 g (0.15 mol) of parahydroxybenzoic acid (=0.10 dl/g) and 48.8 g (0.35 mol) of parahydroxybenzoic acid were used. As a result, ηinh=
A polymer of 0.80 dl/g was obtained, which was determined in the same manner as in Example 1. Table 1 shows the measurement results for each unit content, Tm, and ΔHm. Example 6 A reaction was carried out in the same manner as in Example 1 except that 45.3 g (0.45 mol) of acetic anhydride was used and the polymerization time under vacuum was changed to 5 hours. As a result, ηinh=0.69dl/g
A polymer was obtained, and the content of each unit in the polymer, Tm,
The measurement results of ΔHm are shown in Table-1. Furthermore, the flexural modulus, flexural strength, tensile strength, and elongation at break of the obtained polymer were measured. The measurements were carried out by Nippon Steel Corporation using a J5S injection molding machine, with a cylinder temperature of 250°C, an injection pressure of 50 kg/cl (gauge pressure), and a mold temperature of 50°C.
A rectangular test piece of 40 mm, width 6 mm, and thickness 1 mm was formed. For tensile properties, the straight section was 25 mm long, 3.2 mm wide, and
A dumbbell-shaped test piece with a thickness of 1 mm and an radius of 3R was molded into a test piece made by Toyo Baldwin Co., Ltd. Tensilon UTM-5T.
The bending test was performed using a mold measuring machine at a speed of 1 mm/min.
The distance between the supports was 30 mm, the tensile test was conducted at a speed of 5 mm/min, and the distance between the chucks was 30 mm. The results are shown in Table-2. Furthermore, the temperature dependence of melt viscosity and shear rate was measured. The results are shown in Figure 2. Example 7 Polyethylene terephthalate (ηinh0.64dl/
g) 76.8g (0.4 mol) and parahydroxybenzoic acid
82.8g (0.6 mol) and 0.05g di-n-butyltin oxide
The mixture was charged into a polymerization tube equipped with a stirrer, and the mixture was purged with nitrogen three times, and then the polymerization tube was placed in an oil bath at 275° C. and stirred for 1 hour under a nitrogen stream. Next, the bath temperature was lowered to 230°C, 60 g (0.6 mol) of acetic anhydride was added, and the mixture was stirred for 1 hour and 30 minutes under a nitrogen stream. While acetic acid was being distilled off, the bath temperature was raised again to 275°C, a vacuum of 0.5 Torr was applied, and the mixture was stirred for 7 hours to complete the polymerization. The ηinh of this polymer was 0.44 dl/g. The content of each unit, Tm, and ΔHm of the obtained polymer were as shown in Table 1. Example 8 Polyethylene terephthalate oligomer (ηinh
= 0.10 dl/g), 112.5 moles of parahydroxybenzoic acid, and 9.0 g of stannous acetate were charged into a polymerization tank equipped with a stirrer, and the polymerization tank was replaced with nitrogen.
The temperature was increased to 240°C and stirred for 1.0 hour. Next, 146.3 mol of acetic anhydride was used and the mixture was stirred at 170°C for 1.5 hours. After raising the temperature to 275°C while distilling acetic acid, 16.5g of zinc acetate dihydrate was added and the reaction was carried out at 275°C for 10 hours at 0.3mmHg to obtain a polymer with ηinh = 0.69dl/g. The content of each unit in the obtained polymer, Tm,
ΔHm was as shown in Table-1. The polymer was measured with a capillary rheometer using a 45° tapered nozzle with a diameter of 10 mm at a shear rate of 10 ³ /
Extruded with sec. Extrusion temperature 24℃, extrusion speed 1
cm/min, the sample diameter obtained was 0.4-0.5 mm. The physical properties of the extrudate are shown in Table 3. Young's modulus is manufactured by Toyo Baldwin Co., Ltd.
Using Rheovibron DDV-5-B, density 1.38,
Measurements were made with a measurement length of 40 cm. The coefficient of linear expansion (a) was calculated by measuring the change in elongation of a test piece with a length of 50 cm using a Tensilon SL tensile tester manufactured by Toyo Baldwin. The ultimate elongation (g) is Strograph S-T manufactured by Toyo Seiki.
Changes in elongation were recorded using a video camera using a tensile testing machine.
Read with a displacement measuring device (Width Analyser) and calculate the elongation. The heat shrinkage rate is 80℃, 130℃ in a silicone oil bath.
Calculated by soaking for 30 minutes and measuring the length before and after soaking. Initial length 50cm. The NMR spectrum diagram (along with the integral curve) is shown in Figure 6. Comparative example 1 Polyethylene terephthalate (ηinh=0.64dl/
Polymerization was carried out using 38.4 g (0.20 mol) of g) and 54.1 g (0.30 mol) of para-acetoxybenzoic acid in the same manner as the method described in Japanese Patent Publication No. 18016/1984 (method of Example 1), and ηinh = 0.61. A polymer of dl/g was obtained.
The content and Tm of each unit in the polymer were determined using the same method as in Example 1.
The measurement results of ΔHm are shown in Table-1. Figure 4 shows the temperature dependence of the melt viscosity and shear rate of the obtained polymer. Comparative example 2 Polyethylene terephthalate (ηinh=0.64dl/
The same reaction as in Comparative Example 1 was carried out except that 57.6 g (0.30 mol) of g) and 36.1 g (0.20 mol) of para-acetoxybenzoic acid were used to obtain a polymer having ηinh = 0.57 dl/g. In this case, the content of each unit in the polymer was as shown in Table 1. Figure 5 shows the temperature dependence of the solution viscosity and shear rate of the polymer. Further, Tm in this case was 213°C and ΔHm was 3.7 cal/g. Comparative example 3 Polyethylene terephthalate (ηinh=0.64dl/
g) and 108.6 mol of paraacetoxybenzoic acid.
The same reaction as in Comparative Example 1 was carried out except that 162.9 mol was used and the polymerization time under vacuum was extended to 10 hours. As a result, a polymer having ηinh=0.65 dl/g was obtained. The polymer was extruded at 250° C. using a capillary rheometer using a nozzle with a diameter of 10 mm and a taper of 45° at a shear rate of 10 ³ /sec, and the physical properties of the extrudate are shown in Table 2. Comparative example 4 Polyethylene terephthalate (ηinh=0.64dl/
The same reaction as in Comparative Example 1 was carried out except that 48 g (0.25 mol) of g) and 45.1 g (0.25 mol) of paraacetoxybenzoic acid were used to obtain a polymer having ηinh = 0.67 dl/g. In this case, the content of each unit in the polymer was as shown in Table 1. Also, Tm measured by DSC
was 217°C, and ΔHm was 3.9 cal/g. In addition, Examples 1 to 6 and Comparative Examples 1, 2,
The relationship between Tm of 4 and 5 and (C)/(B) + (C) is shown in Figure 1. In Figure 1, △ indicates a comparative example, and ◯ indicates an example. Comparative Example 5 Polyethylene terephthalate (ηinh=
The same reaction as in Comparative Example 1 was carried out except that 33.6 g (0.175 mol) of para-acetoxybenzoic acid (0.64 dl/g) and 58.6 g (0.325 mol) of para-acetoxybenzoic acid were used to obtain a polymer having ηinh = 0.69 dl/g. The content of each unit in the obtained polymer,
Tm and ΔHm were as shown in Table-1.

【table】

【table】

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【table】 [Brief explanation of drawings]

Figure 1 shows the relationship between the melting point (Tm) and composition of the copolyester of the present invention, and Figures 2 and 3 and Figures 4 and 5 show the melt viscosity and shear rate of the copolyester in Examples and Comparative Examples, respectively. shows the temperature dependence of FIG. 6 shows the NMR spectrum of the copolymerized polyester in the example.

Claims (1)

[Claims] 1. A dicarboxylic acid unit represented by general formula (A), (In the formula, at least 60 mol% or more of R ¹ is 1,
4-phenylene group, and 40 mol% or less is 1,4
- C ₆ to _{C 16} divalent aromatic hydrocarbon group other than phenylene group, C ₄ to _{C 20} divalent alicyclic hydrocarbon group, or C ₁ to C ₄₀ divalent aliphatic hydrocarbon group shows.
However, the hydrogen atom of the benzene ring of the aromatic hydrocarbon group (including 1,4-phenylene group) may be substituted with a halogen atom, a C ₁ to C ₄ alkyl group, or an alkoxy group) according to the general formula ( Glycol unit represented by B) -O- ^R2 -O-...(B) (wherein, ^R2 is a _C1 to _C20 divalent aliphatic hydrocarbon group or a _C4 to _C20 divalent aliphatic hydrocarbon group) (represents an alicyclic hydrocarbon group) and an oxycarboxylic acid unit represented by the general formula (C) (In the formula, at least 60 mol% or more of R ³ is 1,
4-phenylene group, and 40 mol% or less is 1,4
- Indicates a C ₆ to C ₁₆ divalent aromatic hydrocarbon group other than a phenylene group. However, aromatic hydrocarbon groups (1,
The hydrogen atom of the benzene ring (including the ₄ -phenylene group) may be substituted with a halogen atom, a C1- _C4 alkyl group or an alkoxy group), but one of the oxycarboxylic acid units (C) is combined with a part of the glycol unit (B) through an ether bond to form the general formula (D). (In the formula, R ² and R ³ are in formulas (B) and (C)
The content of ^dicarboxylic acid unit ( ^A ) is 10 to 40 mol%, and the content of dicarboxylic acid unit (A) and oxycarboxylic acid unit is 10 to 40 mol%. The ratio (C)/(A)+(C) of oxycarboxylic acid unit (C) to the total amount of (C) is 30 to 80 mol%, and the ratio of glycol unit (B) and oxycarboxylic acid unit (C) is 30 to 80 mol%. The ratio (C)/(B) + (C) of the oxycarboxylic acid unit (C) to the total amount is 30 to 80 mol%, and the ratio (D)/(B) of the unit (D) to the glycol unit (B) is 30 to 80 mol%. ) is 3 to 20 mol%, the ratio (molar ratio) of unit (B) to unit (A) is 1≦(B)/(A)≦1.1, and the ratio of phenol to tetrachloroethane is 1:1 ( weight ratio) in a mixed solution
The logarithmic viscosity ηinh measured at 30℃ at a concentration of 0.5g/dl is
0.4 dl/g or more, and the copolyester is a raw material polyester or oligoester consisting of repeating units represented by general formula (E). (In the formula, R ¹ and R ² are the general formula (A) and
R ¹ and R ² in (B) have the same meanings) An oxycarboxylic acid represented by the general formula (H) and HO−R ³ COOH...(H) (wherein, R ^{3 is R 3 in} the general formula shown above) ) is reacted to form a copolymerized oligomer, an acetylating agent is added to perform acetylation and polymerization, and the reaction is then completed under reduced pressure. , copolymerized polyester.