JPH1095841A - Copolyester and molded item produced therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolyester which can give a molded item excellent in melt moldability, shape stability, transparency, etc., by selecting a copolyeser which mainly comprises terephthalic acid units and ethylene glycol units and further contains specific diol units and specific polyfunctional compd. units. SOLUTION: This copolyester mainly comprises terephthalic acid units and ethylene glycol units and further contains the following comonomer units: 0.5-7mol% (based on the total numbers of moles of all the structural units; the same ' applies hereunder) at least either diol units represented by formula I (wherein A is -CH2 CH2 -, etc.; B is a divalent hydrocarbon group. etc.; and R<1> and R<2> are each an inert group) or diol units represented by formula II (wherein A is -CH2 CH2 -, etc.; and R<3> is inere substituent group) and 0.005-0.5mol% polyfunctional compd. units derived from at least one polyfunctional compd. having at least three carboxyl (and/or its ester-forming) or hydroxyl (and/or its ester-forming) groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a copolymerized polyester, a method for producing the same, a method for producing a molded article using the copolymerized polyester, and a molded article obtained by the method. More specifically, the present invention has a non-Newtonian property, which has a high melt viscosity, a low viscosity at a high shear rate, and a high viscosity at a low shear rate, and a melt fracture such as sharkskin flow occurs during molding. The present invention relates to a copolymerized polyester having excellent properties that a crystallization rate is suppressed and a gelled product is not generated, and a method for producing the same, and a molded article made of the copolymerized polyester, using the copolymerized polyester of the present invention. When molded articles are manufactured by extrusion blow molding or other melt molding methods, they have excellent transparency, appearance, and tactile sensation, as well as mechanical properties such as impact resistance, mechanical properties, heat resistance, and moisture resistance. It is possible to smoothly produce a high-quality molded product having excellent properties and chemical resistance. The copolyesters of the invention are particularly suitable for extrusion blow molding.

[0002]

2. Description of the Related Art Polyester resins such as polyethylene terephthalate are excellent in various properties such as transparency, mechanical properties, gas barrier properties, and flavor barrier properties. As it is less worrying about chemicals and is superior in hygiene and safety, juices, soft drinks,
In recent years, it has been widely used as a hollow container for filling seasonings, oils, cosmetics, detergents, and other products.

[0003] As a typical molding method for producing a hollow molded article such as a container from plastic, (1) a molten plasticized resin is extruded as a cylindrical parison through a die orifice, and the parison is in a softened state. An extrusion blow molding method in which a fluid such as air is blown into a mold while being sandwiched between molds, and (2) a molten parison (preform) is once molded by injecting a molten resin into the mold and then molded. The injection blow molding method in which the mold is inserted into a blow mold and a fluid such as air is blown to perform molding.

Among the above-mentioned molding methods, the former extrusion blow molding method has a simpler process than the latter injection blow molding method, and does not require a high level of technology for manufacturing and molding a mold. In addition, equipment costs and mold manufacturing costs are low, making it suitable for high-mix low-volume production. In addition, the extrusion blow molding method has an advantage that a molded article having a complicated shape having a small object, a deep object, a large object, a handle, and the like can be produced.

[0005] From this point, various attempts have been made to carry out extrusion blow molding using a general-purpose polyester resin such as polyethylene terephthalate or polybutylene terephthalate. However, general-purpose polyester resins generally have low melt viscosities. For this reason, when extrusion blow molding is performed, it is difficult for the parison after extrusion to significantly draw down and shape. In addition, there is a problem that crystallization is apt to occur at the time of blowing after extrusion, transparency is impaired, and shaping failure occurs. The disadvantages caused by low melt viscosity and easy crystallization in general-purpose polyester resins such as polyethylene terephthalate are as follows: the length required for the production of large hollow molded products is usually 30 cm or more. This is particularly noticeable in extrusion blow molding in which a long parison is extruded. Therefore, it is practically extremely difficult to obtain a molded product having a uniform shape and dimensions and excellent transparency, particularly a large hollow molded product, by extrusion blow molding using a general-purpose polyester resin such as polyethylene terephthalate. is there.

Therefore, for the above reasons, in extrusion blow molding, vinyl chloride resins and polyolefins, which have a high melt viscosity and do not cause remarkable drawdown of a parison extruded in a molten state, have been mainly used. Have been. However, extrusion blow-molded products manufactured using vinyl chloride resin have problems in hygiene and safety due to elution of harmful additives such as plasticizers and metal-based stabilizers. There is a problem that toxic gas is generated when incinerated, and its use tends to decrease mainly in Europe. Further, when extrusion blow molding is performed using a polyolefin such as polyethylene, there is a disadvantage that opacity derived from crystals is generated in the molded product, and the transparency and appearance of the molded product are likely to be poor.

For this reason, various proposals have been made on polyester resins suitable for extrusion blow molding. Such conventional techniques include, for example, a method for producing a polyester by reacting a dicarboxylic acid or its ester-forming component with a diol component. For producing a copolyester used for extrusion blow molding or the like using a diol component containing an ethylene oxide adduct of bisphenol A (JP-A-4-59822, JP-A-5-65338, JP-A-5-58338) 125
165 and JP-A-5-186579); When a polyester is produced by reacting a dicarboxylic acid or an ester-forming component thereof with a diol component, a copolymerized polyester is prepared by using cyclohexanedimethanol or the like as a diol component. Manufacturing method (Comparative Example of JP-A-5-65338 and JP-A-7-20
A method of producing a branched polyester using terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol and a small amount of a multifunctional branching agent compound (see U.S. Defense Publication No. T954,005); Along with dicarboxylic acid components such as acids and their ester-forming derivatives and diol components such as ethylene glycol, general-purpose multifunctional components such as trimethylolpropane, pentaerythritol and trimellitic acid, and chain stoppers such as benzoic acid and stearic acid. Method for producing a copolyester for extrusion blow molding using the same (see JP-A-54-137095); Esterification reaction of a dicarboxylic acid component such as terephthalic acid or an ester-forming derivative thereof with a diol component such as ethylene glycol Or ester exchange After reacting to produce a low polymer, a general-purpose crosslinking agent such as trimethylolpropane, pentaerythritol, and trimellitic acid is reacted with the low polymer to form a prepolymer, and a prepolymer is formed. To produce a copolymerized polyester for extrusion blow molding (JP-A-54
JP-A-163962 and JP-A-55-92730); Copolymerized polyester for extrusion blow molding using a branching agent such as terephthalic acid, isophthalic acid and pentaerythritol and a terminal blocking agent such as m-anisic acid. Production method (see JP-A-61-181823); terephthalic acid, ethylene glycol, bisphenol A diglycol ether or bis [4- (2-hydroxyethoxy) phenyl] sulfone, and a small amount of a polyfunctional branching compound For producing a branched polyester by using a method (US Pat. No. 3,558,557, JP-A-54-8).
3997 and JP-A-55-121029);
Etc. are known.

In the case of the above and the conventional methods, the melting point of the copolymerized polyester is lowered by copolymerization of an ethylene oxide adduct of bisphenol A and cyclohexane dimethanol, thereby lowering the melt extrusion temperature to a temperature lower than the conventional one. To be able to set
The melt viscosity during extrusion blow molding can be increased. However, even in that case, the melt viscosity is not high enough to perform extrusion blow molding, so that a significant drawdown occurs in the parison after extrusion, making it difficult to shape, and making extrusion blow molding smooth. Can't do it. Further, as an adverse effect of molding at a low temperature, an extrusion blow molded product such as a bottle has minute surface roughness, and the appearance and feel of the molded product are easily impaired. In addition, the copolymerized polyester obtained by the above and the conventional methods often cannot perform solid-state polymerization due to a low melting point, and even when solid-state polymerization can be performed, the solid-state polymerization rate is extremely slow. Since the degree of polymerization is not sufficiently increased, an increase in melt viscosity is difficult to achieve, and a molded article obtained from the copolymerized polyester has disadvantages such as poor transparency and large thickness unevenness.

Further, in the above-mentioned conventional method, 1,4-cyclohexanedimethanol is added in an amount of 1 to all diol units.
Since the copolymerization is carried out at a high ratio of 0 to 40 mol%, low-temperature molding is possible by amorphization or lowering of the melting point in the same manner as in the conventional method, and the conventional method is carried out by a branched structure using a polyfunctional branching agent compound. The melt viscosity of the polyester tends to be higher than that of the copolymerized polyesters obtained in and. However, the conventional method does not mention solid-state polymerization at all. And, the copolymerized polyester obtained by the conventional method is a so-called “amorphous” polymer or is crystalline, but its melting point is too low, so that solid-phase polymerization is impossible, or Even if polymerization is possible, the melting point is too low when solid-phase polymerization is performed, and sticking between chips or pellets occurs or the polymerization rate is too low,
The molecular weight cannot be increased sufficiently. Therefore, the melt viscosity of the copolymerized polyester obtained therefrom is not high enough to perform extrusion blow molding, and as a result, remarkable drawdown of the parison after extrusion occurs, shaping becomes difficult, and extrusion blow molding becomes smooth. Can't do it. Further, even in the conventional method, as in the above and the prior arts, as an adverse effect of molding at a low temperature, an extruded blow-molded product such as a bottle has minute surface roughness, and the appearance and feel of the molded product are likely to be impaired. Furthermore, if the copolyester is dried at a high temperature before molding, chips and pellets will adhere to each other and must be dried at a low temperature. Therefore, it is necessary to dry for a long time using a large-scale apparatus such as a vacuum drying facility. , Reducing productivity. In addition, in the case of an amorphous polymer, sticking between chips and pellets is likely to occur at the lower part of the hopper of the extruder, which causes a disadvantage that extrusion cannot be performed.

The polyester obtained by the above-mentioned conventional method using a cross-linking agent comprising a polyfunctional compound and a chain terminator such as benzoic acid or stearic acid has a higher melt viscosity than an ethylene terephthalate homopolymer or the like. And the melt strength is increased, but the crystallization rate is higher than that of ethylene terephthalate homopolymer, so spherulites are formed during parison extrusion, and the resulting extruded blow-molded products are significantly whitened, resulting in higher transparency. Will be lacking. In addition, when extruding a parison with a length of 30 cm or more to produce a large hollow molded product by extrusion blow molding, the lower part of the parison solidifies due to crystallization, and the pinch-off portion at the bottom of the container such as a bottle is considered to have poor adhesion. Become.
In addition, as in the case of the above-mentioned conventional methods (1) to (4), the surface of the molded product is minutely roughened, and the appearance and the touch of the molded product are liable to be extremely poor. Furthermore, in terms of the productivity of the copolymerized polyester, since the crystallinity sharply increases during solid-phase polymerization, diffusion of ethylene glycol in the polymer required to increase the polymerization rate is prevented, It is difficult to produce the desired copolymerized polyester smoothly. Further, since the copolymerized polyester obtained by the conventional method has an unusually high degree of crystallinity, unmelted particles frequently occur in an extrusion step in extrusion blow molding, and it is difficult to produce a good molded product. The above-mentioned various drawbacks are particularly prominent when the resin extrusion speed is high, such as when a large hollow molded product is manufactured.

Furthermore, the copolymerized polyester obtained by the above-mentioned conventional method has a higher crystallization rate than that of the ethylene terephthalate homopolymer, similarly to the copolymerized polyester obtained by the above-mentioned conventional method. Occasionally, spherulites are formed, and the resulting extrusion blow-molded product or the like is significantly whitened or lacks transparency. In addition, in the production of a large hollow molded product involving the extrusion of a parison having a length of 30 cm or more, the lower portion of the parison is solidified by crystallization, and the pinch-off portion at the bottom of the hollow molded product such as a bottle has poor adhesion. . Furthermore, the degree of crosslinking of the copolymerized polyester cannot be properly controlled,
Due to the over-crosslinked state, there is a disadvantage that a gel-like substance derived from the over-crosslinked structure is generated, and spots such as bumps appear on the molded article, thereby impairing the appearance of the molded article. Further, in the case of the conventional method, as in the case of the above-mentioned conventional methods (1) to (4), the surface of the molded product is minutely roughened, and the appearance and feel of the molded product are liable to be extremely poor. The above-mentioned Japanese Patent Application Laid-Open No. 54-163 is disclosed as a prior art.
962 and JP-A-55-92730 describe that a small amount of isophthalic acid, neopentyl glycol and the like can be copolymerized, in which case the crystallization speed of the copolymerized polyester is suppressed. Premature solidification of the bottom of the parison and whitening of the hollow molded product during the production of hollow molded products are reduced to some extent, but the generation of gel-like materials due to the overcrosslinked structure and the rough surface of the molded product are still eliminated Remains untouched.

In the above-mentioned conventional method, the melt viscosity and the shear sensitivity of the melt viscosity are increased by copolymerizing a branching agent such as pentaerythritol and a terminal blocking agent such as m-anisic acid and then performing solid phase polymerization. It is said that a copolyester with a small amount of gel derived from the hypercrosslinked structure can be obtained, and the copolymerization of isophthalic acid as a bifunctional component suppresses the crystallization rate of the copolyester to produce a hollow molded article. The crystallization rate of the copolyester at the bottom of the parison during the process is suppressed, and the solidification of the bottom of the parison and the whitening of the hollow molded product during the production of the hollow molded product tend to be reduced to some extent. However, when producing a large hollow molded article with the extrusion of a long parison of 30 cm or more using the conventional copolymerized polyester,
There is a disadvantage that crystallization occurs in the bottom of the previously extruded parison, and the bottom of the hollow molded article is whitened. And
Also in the case of this conventional method, as in the case of the above-mentioned conventional methods, the surface of the molded product is minutely roughened, and the appearance and touch are likely to be extremely poor. In particular, 3
When the extrusion amount per unit time is 20 kg or more, such as when manufacturing a large hollow molded product involving the extrusion of a parison having a length of 0 cm or more, minute surface roughness of the molded product becomes remarkable, and In addition, the generation of unmelted particles due to the difficulty in melting the crystals is likely to occur in the molded product.

In the above-mentioned conventional method, bisphenol A diglycol ether or bis [4- (2-hydroxyethoxy) phenyl] sulfone is copolymerized. Low temperature molding is possible, and the branched structure of the polyfunctional branching agent compound tends to increase the melt viscosity of the polyester as compared with the copolymerized polyester obtained by the conventional method. However, the conventional method does not mention solid-state polymerization at all like the conventional method. Since the copolymerized polyester obtained by the conventional method has an increased degree of polymerization only by melt polymerization, the limit of increasing the molecular weight is low. Therefore, the melt viscosity of the obtained copolyester is not sufficiently high, and in extrusion blow molding of a large hollow molded product accompanied by extrusion of a parison having a length of 30 cm or more, remarkable drawdown of the parison after extrusion occurs and shaping. And it is difficult to perform extrusion blow molding smoothly. Further, in order to obtain a copolymerized polyester having a high viscosity by melt polymerization, bisphenol A diglycol ether or bis [4- (2-hydroxyethoxy) phenyl] sulfone and a polyfunctional branching agent compound are used in a large amount, If the viscosity is to be increased, the polyester is exposed to a high temperature for a long time during the melt polymerization, causing thermal decomposition of bisphenol A diglycol ether or bis [4- (2-hydroxyethoxy) phenyl] sulfone, etc., thereby deteriorating the color of the polyester. In addition, the melt viscosity is not properly controlled, and when subjected to extrusion blow molding, the appearance and tactile sensation of the molded product are impaired, making it difficult to perform molding smoothly. Further, even in the conventional method, as in the above and the prior arts, as an adverse effect of molding at a low temperature, an extruded blow-molded product such as a bottle has minute surface roughness, and the appearance and feel of the molded product are likely to be impaired. In addition, bisphenol A diglycol ether or bis [4- (2-hydroxyethoxy) phenyl]
If the copolymerization amount of the sulfone increases and the crystallinity of the chips decreases, drying the copolymerized polyester at a high temperature before molding will cause sticking between the chips and pellets and must be dried at a low temperature. It requires long-time drying by a large-scale apparatus, and the productivity is reduced. In addition, in the case of an amorphous polymer, sticking between chips and pellets is likely to occur at the lower part of the hopper of the extruder, which causes a disadvantage that extrusion cannot be performed.

Further, none of the copolymerized polyesters obtained by the above-mentioned conventional methods and molded articles made of the same have sufficiently high mechanical properties such as drop impact strength. In the case of a hollow molded article such as a bottle, its drop impact strength needs to be 1 m or more, but a bottle was manufactured by extrusion blow molding using the copolymerized polyester obtained by the above-mentioned conventional method. However, in all cases, the drop impact strength was less than 1 m, which caused a practical problem. In particular, in a bottle having an internal volume of 1 liter or more, the breaking energy is increased and the bottle is easily broken. The bottle obtained by the conventional copolyester has particularly poor drop impact strength, which is presumed to be due to the decrease in the mechanical and mechanical properties of the copolyester by copolymerization of isophthalic acid. .
In addition, the present inventors have tried to produce polyethylene terephthalate having a high degree of polymerization by solid-state polymerization, which is different from the above-mentioned prior arts. It has been found that polyethylene terephthalate having a sufficiently high degree of polymerization and melt viscosity suitable for, for example, cannot be efficiently obtained in a short time, and is not practical in terms of productivity.

[0015]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned various problems. (1) When the melt viscosity is sufficiently high and the melt is extruded when used for extrusion blow molding or the like. (2) Slow crystallization speed, no spherulites are formed during extrusion of the parison, and molding of the resulting extruded blow-molded product etc. (3) When manufacturing a large hollow molded product in which a parison having a length of 30 cm or more is extruded, solidification due to crystallization of the lower part of the parison does not occur, and molding of a bottle or the like is not performed. (4) Various molded products having no fine surface roughness and excellent in appearance and feel can be obtained; (5) Difficult-to-melt crystals derived from a hypercrosslinked structure Also Ku has less occurrence of gels, spots such as fish eyes does not occur in the molded product,
(6) The obtained molded article is excellent in impact resistance; and (7) The solid phase polymerization rate is large and the productivity is excellent. With excellent properties such as melt-moldability, especially extrusion blow-moldability, and high-quality molded products with excellent shape stability, dimensional accuracy, appearance, touch, and transparency. The purpose is to provide a polyester that can be manufactured. An object of the present invention is to provide a method capable of producing a polyester having the above-mentioned excellent properties in a short time with high productivity. Furthermore, an object of the present invention is to provide a method for producing a molded article by melt-molding, particularly extrusion blow molding, using a polyester having the above-mentioned excellent properties, and to provide a molded article by the method.

[0016]

SUMMARY OF THE INVENTION Under the circumstances described above, the polyester resin described above is used for the above-mentioned high functionality and increasingly developing applications, especially for extrusion blow molding for producing large hollow molded products. Focusing attention, various studies have been conducted on copolymerized polyesters based on polyethylene terephthalate-based polymers. As a result, a dicarboxylic acid component composed of terephthalic acid and a diol component composed of ethylene glycol and a small amount of an ethylene oxide adduct of bisphenol A are found. After the esterification reaction, a polymerization reaction is performed in a molten state to form a prepolymer, and the prepolymer is subjected to solid-phase polymerization, whereby the degree of polymerization of the polyester can be increased in a short time. The melt viscosity of polyester during extrusion blow molding can be increased, Sex, hollow molded articles excellent in such has been found to give the appearance (see JP-A-6-99476 and JP-A No. 7-258396).

Based on the above findings, the present inventors have further studied and found that, in a polyester mainly composed of a terephthalic acid unit and an ethylene glycol unit, the polyester further contains other units than the terephthalic acid unit and the ethylene glycol unit. A specific diol unit having a benzene nucleus of a specific content is contained in a specific ratio, and a polyfunctional compound unit composed of a specific polyfunctional compound having three or more functional groups is contained in a specific ratio, and solidified to a specific intrinsic viscosity. When the degree of polymerization is increased by phase polymerization, the resulting copolymerized polyester is obtained as described in JP-A-6-994.
No. 76 and the invention according to Japanese Patent Application Laid-Open No. 7-258396. Non-Newtonian properties such as high degree of polymerization in a short time, low viscosity at high shear rate and high viscosity at low shear rate. JP-A-6-9947 for molding
No. 6 and Japanese Patent Application Laid-Open No. 7-258396, which can be carried out more smoothly, and is particularly suitable for producing a large hollow molded product by extrusion blow molding with extrusion of a parison having a length of 30 cm or more. It has good moldability, has a sufficiently high melt viscosity, does not cause drawdown of the extruded parison, and has found that a hollow molded article excellent in transparency, color tone, appearance and touch can be smoothly formed. .

Moreover, the above-mentioned copolymerized polyester developed by the present inventors has a low crystallization rate, and does not generate spherulites during extrusion of the parison during extrusion blow molding.
The blow-molded product obtained is excellent in transparency without whitening. Further, when producing a large hollow molded product with extrusion of a parison longer than 30 cm, solidification due to crystallization of the lower part of the parison does not occur. It was also found that poor adhesion at the pinch-off portion at the bottom of molded products such as bottles did not occur. In addition, the above-mentioned copolymerized polyester developed by the present inventors shows an appropriate shear stress at the time of melt molding, and therefore, a molded product obtained by the melt molding has a good appearance and touch feeling without surface roughness, Furthermore, they have found that the degree of crosslinking is well adjusted, no gel-like substance is generated due to excessive crosslinking, the transparency is excellent, and the mechanical strength is excellent. In addition, the present inventors have found that the copolymerized polyester has a high solid-state polymerization rate and can be produced economically with good productivity, and has completed the invention based on those various findings.

That is, the present invention provides (1) a copolymerized polyester mainly comprising a dicarboxylic acid unit composed of a terephthalic acid unit and a diol unit composed of an ethylene glycol unit and having another copolymerized unit; (I) (a) the following general formula (I);

[0020]

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Wherein A is a group represented by the formula: —CH ₂ CH ₂ — or —CH (CH ₃ ) CH ₂ —, B is a divalent hydrocarbon group, a carbonyl group, a sulfonyl group, an oxygen An atom or a direct bond (-), R ¹ and R ² each represent an inert substituent, j and k each independently represent an integer of 0 to 8, and s and t each independently represent an integer of 0 to 4 And (b) a diol unit represented by the following general formula (II):

[0022]

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Wherein A is a group represented by the formula: —CH ₂ CH ₂ — or —CH (CH ₃ ) CH ₂ —, R ³ is an inert substituent, and m and n are each independently An integer of 0 to 8, and u represents an integer of 0 to 4). A diol unit (II) represented by the following formula: wherein at least one bifunctional compound unit selected from the total number of moles of all structural units of the copolymerized polyester is used. (Ii) at least three carboxyl groups, hydroxyl groups and / or their ester-forming groups, and at least one of them has a carboxyl group, a hydroxyl group and / or an ester-forming group thereof. The polyfunctional compound unit (III) derived from at least one polyfunctional compound which is a group or an ester-forming group thereof is 0.000.00
(3) A copolymerized polyester characterized by having an intrinsic viscosity of 1.0 to 1.4 dl / g. The present invention provides a method for producing a copolymerized polyester mainly comprising a dicarboxylic acid unit composed of a terephthalic acid unit and a diol unit composed of an ethylene glycol unit, and having another copolymerized unit; It is mainly composed of a dicarboxylic acid component composed of an ester-forming derivative and a diol component composed of ethylene glycol. In addition to the above-mentioned main dicarboxylic acid component and the diol component, (a) the following general formula (IV):

[0024]

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Wherein A is a group represented by the formula: —CH ₂ CH ₂ — or —CH (CH ₃ ) CH ₂ —, B is a divalent hydrocarbon group, a carbonyl group, a sulfonyl group, an oxygen An atom or a direct bond (-), R ¹ and R ² each represent an inert substituent, j and k each independently represent an integer of 0 to 8, and s and t each independently represent an integer of 0 to 4 A diol (IV) represented by the following general formula (V):

[0026]

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Wherein A is a group represented by the formula: —CH ₂ CH ₂ — or —CH (CH ₃ ) CH ₂ —, R ³ is an inert substituent, and m and n are each independently (I) an integer of 0 to 8, and u represents an integer of 0 to 4); and at least one bifunctional compound selected from ester-forming derivatives thereof; and (b) a carboxyl group. , A hydroxyl group and / or an ester-forming group thereof, and at least one of them is a carboxyl group or an ester-forming group thereof.
And (c) the content of the bifunctional compound in the reaction material is higher than the content of the diol unit (I) and / or the diol unit (II) derived from the bifunctional compound. (D) the content of the polyfunctional compound in the reaction raw material is 0.5 to 7 mol% based on the total number of moles of all structural units of the copolymerized polyester; The reaction raw material having an amount such that the ratio of the polyfunctional compound unit (III) derived from the functional compound is 0.005 to 0.5 mol% based on the total number of moles of all the structural units of the copolymerized polyester is obtained by esterification. After the esterification reaction or transesterification reaction, it is melt-polymerized to form a polyester prepolymer; and [2] the polyester prepolymer obtained in the step [1] is subjected to solid-state polymerization; The method for producing the copolyester according to claim.

The present invention also relates to a molded article comprising the above-mentioned copolymerized polyester, particularly an extrusion blow molded article. The present invention is a method for producing a molded product by performing extrusion blow molding using the above-mentioned copolymerized polyester.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail. As described above, the copolymerized polyester of the present invention needs to be a copolymerized polyester mainly composed of terephthalic acid units and ethylene glycol units and having other copolymerized units. In the copolymerized polyester of the present invention, the total ratio (mol%) of the terephthalic acid unit and the ethylene glycol unit is calculated from the total mole number of all the structural units constituting the copolymerized polyester (that is, 100 mol%), and It is a value obtained by subtracting the ratio of (I) and / or the diol unit (II), the polyfunctional compound unit (III) and the like. Generally, the total ratio (mol%) of terephthalic acid units and ethylene glycol units in the copolymerized polyester of the present invention is about 70 to 70 based on the total number of moles of all structural units constituting the copolymerized polyester.
Preferably it is 98 mol%, more preferably about 90-98 mol%. If the total proportion of terephthalic acid units and ethylene glycol units in the copolyester is less than 70 mol%, the copolyester becomes amorphous, so that it is difficult to increase the degree of polymerization by solid phase polymerization. If it exceeds, the crystals of the copolymerized polyester are hardly melted, and unmelted particles are apt to occur in the molded product, which is not preferable.

Then, the copolymerized polyester of the present invention is
In addition to the terephthalic acid unit and the ethylene glycol unit, at least one bifunctional compound selected from the diol unit (I) represented by the above general formula (I) and the diol unit (II) represented by the above general formula (II) The compound unit is defined as 0.1 based on the total number of moles of all structural units of the copolymer polyester.
It is necessary to have 5 to 7 mol%. When the bifunctional compound unit is, for example, an isophthalic acid unit, a hydroxybenzoic acid unit, or the like, a small surface roughness occurs in an extrusion blow-molded product such as a bottle, and the appearance and feel of the molded product are significantly impaired. In particular, the surface roughness becomes remarkable in the production of molded products such as large bottles having an extrusion rate of 20 kg / hour or more, and the impact resistance of the molded products is also poor.

In the copolymerized polyester of the present invention, in the diol unit (I) and / or the diol unit (II), the group A is a group represented by the formula: —CH ₂ CH ₂ — (ethylene group) or the formula: It is a group (1,2-propylene group) represented by CH (CH ₃ ) CH ₂ —. In the copolymerized polyester of the present invention, in the diol unit (I) and / or the diol unit (II) contained therein, even if all of the groups A are ethylene groups, all of the groups A are 1,2-
Even if it is a propylene group, a part of group A may be an ethylene group and the remaining group A may be a 1,2-propylene group. Among them, the diol unit (I) in the copolymerized polyester
It is preferable that the group A in the diol unit (II) is an ethylene group from the viewpoint of the easiness of production of the copolymerized polyester and the production cost.

The group B in the diol unit (I)
Is a divalent hydrocarbon group, a carbonyl group, a sulfonyl group,
It is an oxygen atom or a direct bond (-). When the group B is a divalent hydrocarbon group, an alkylene group having 1 to 8 carbon atoms;
It is preferably an alkylidene group or a divalent aromatic group, and specifically, for example, a methylene group, a dichloromethylene group, an ethylene group, an ethylidene group, a propylene group, a propylidene group, a trimethylene group, an isopropylidene group, a butylidene group , Ethylethylene group, tetramethylene group, 1
-Methylpropylidene group, 1,2-dimethylethylene group, pentylidene group, 1-methylbutylidene group, pentamethylene group, 1-ethyl-2-methylethylene group, 1,
3-dimethyltrimethylene group, 1-ethylpropylidene group, trimethylethylene group, isopropylmethylene group,
1-methylbutylidene group, 2,2-dimethylpropylidene group, hexamethylene group, 1-ethylbutylidene group,
1,2-diethylethylene group, 1,3-dimethylbutylidene group, ethyltrimethylethylene group, heptamethylene group, octamethylene group, 1,1-cyclopentylidene group, 1,1-cyclohexylidene group, Examples thereof include a 1-cycloheptylidene group, a 1,1-cyclooctylidene group, a benzylidene group, and a 1-phenylethylidene group.

In the copolyester of the present invention, all the groups B in the diol unit (I) present in the copolyester may be the same or different. Among them, in the copolymerized polyester of the present invention,
It is preferable that the group B in the diol unit (I) is an isopropylidene group, a sulfonyl group and / or a 1,1-cyclohexylidene group from the viewpoint of improving the thermal stability of the copolymerized polyester at the time of melting.

In the copolymerized polyester of the present invention, j, k, m and n in the diol unit (I) and / or the diol unit (II) are each independently an integer of 0 to 8, and thus j, k, and m and n may be the same number or different numbers. Among them,
J, k, m, and n are each independently from the viewpoint of easiness of production of the copolymerized polyester, thermal stability at the time of melting of the copolymerized polyester, and good color tone of a molded article using the copolymerized polyester. It is preferably 1 or 2, and more preferably j, k, m and n are each 1.

In the diol unit (I) and / or diol unit (II) of the copolymerized polyester of the present invention,
The benzene nucleus may be substituted by inert substituents (R ^{1 to} R ³ ), in which case the inert substituents R ¹ , R ² and R
³ is preferably a lower alkyl group such as a methyl group, an ethyl group and a propyl group; and a halogen atom such as chlorine, bromine and iodine. In addition, s, t, and u representing the number of inert substituents in the diol unit (I) and / or the diol unit (II) are each preferably 0 to 2, and more preferably 0.

The diol unit (I) constituting the copolymerized polyester of the present invention may be any of the above-mentioned diol units. Preferred examples of the diol unit (I) include 2,2-bis [4 -(2-hydroxyethoxy) phenyl] propane, 2- {4- [2- (2-hydroxyethoxy) ethoxy] phenyl} -2- [4 '
-(2-hydroxyethoxy) phenyl] propane,
2,2-bis {4- [2- (2-hydroxyethoxy)
Ethoxy] phenyl} propane, bis [4- (2-hydroxyethoxy) phenyl] sulfone, {4- [2-
(2-Hydroxyethoxy) ethoxy] phenyl}-
[4 ′-(2-hydroxyethoxy) phenyl] sulfone, bis {4- [2- (2-hydroxyethoxy) ethoxy] phenyl} sulfone, 1,1-bis [4- (2-
Hydroxyethoxy) phenyl] cyclohexane, 1-
{4- [2- (2-hydroxyethoxy) ethoxy] phenyl} -1- [4 ′-(2-hydroxyethoxy) phenyl] cyclohexane, 1,1-bis {4- [2-
Examples of diol units derived from (2-hydroxyethoxy) ethoxy] phenyl} cyclohexane, 2,2-bis [4- (2-hydroxyethoxy) -2,3,5,6-tetrabromophenyl] propane, and the like. Can be. Among the diol units derived from the above compounds, the diol unit (I) is 2,2-bis [4- (2
In the case of -hydroxyethoxy) phenyl] propane unit or bis [4- (2-hydroxyethoxy) phenyl] sulfone unit, the production of the copolymerized polyester is facilitated and the melt stability of the copolymerized polyester is increased. And the color tone of a molded article produced using the copolymerized polyester can be improved.

The diol unit (II) constituting the copolymerized polyester of the present invention may be any of the above-mentioned diol units. Preferred examples of the diol unit (II) include 1,4-bis (2-hydroxyethoxy) benzene, 1- (2-hydroxyethoxy) -4
Examples thereof include diol units derived from-[2- (2-hydroxyethoxy) ethoxy] benzene, 1,4-bis [2- (2-hydroxyethoxy) ethoxy] benzene, and the like. When the diol unit (II) is a 1,4-bis (2-hydroxyethoxy) benzene unit among the diol units derived from the above-described compounds, the production of the copolymerized polyester is facilitated and the copolymerization is facilitated. Melt stability of polyester can be increased,
Further, the color tone of a molded article produced using the copolymerized polyester can be improved.

The copolymerized polyester of the present invention comprises, as diol unit (I) and / or diol unit (II),
It may have only one kind of the above-mentioned diol units, or may have two or more kinds.

In the copolymerized polyester of the present invention, the ratio of the diol unit (I) and / or the diol unit (II) [two or more diol units (I) and / or
Or, in the case of having a diol unit (II), the total proportion thereof] should be 0.5 to 7 mol% based on the total number of moles of all structural units of the copolymerized polyester, as described above. It is. When the proportion of the diol unit (I) and / or the diol unit (II) is less than 0.5 mol%, the crystallization rate of the copolymerized polyester becomes too fast, and whitening accompanying the formation of spherulites during melt molding occurs. As a result, the transparency of the molded article is lost, and in the production of a large hollow molded article accompanied by the extrusion of a parison having a length of 30 cm or more, the lower part of the parison solidifies early due to crystallization, so that bottles and the like are hardened. The pinch-off portion at the bottom of the molded product has poor adhesion. In addition, when the degree of crystallinity is too high, unmelted bumps are formed on the molded product when melt molding is performed, resulting in poor appearance.

On the other hand, when the proportion of the diol unit (I) and / or the diol unit (II) exceeds 7 mol%, the crystallinity and melting point of the copolymerized polyester become too low.
Even if solid-state polymerization cannot be performed, or even when solid-state polymerization can be performed, the solid-state polymerization rate becomes extremely slow and the degree of polymerization does not sufficiently increase, and the resulting copolyester and its molded article Is inferior in mechanical strength.

The proportion of the diol unit (I) and / or the diol unit (II) in the copolymerized polyester can increase the productivity of the copolymerized polyester itself,
In addition, the melt viscosity of the copolymerized polyester is sufficiently high, so that melt molding such as extrusion blow molding can be performed more favorably, and there is no whitening, the transparency is further excellent, and the mechanical strength is further excellent. From the viewpoint of obtaining the following, the amount is preferably in the range of 1.5 to 5 mol% based on the total number of moles of all the structural units of the copolymerized polyester.

By the way, a small amount of diethylene glycol units is contained in the copolymerized polyester produced by producing a small amount of diethylene glycol, which is a dimer of ethylene glycol, during the production of the copolymerized polyester of the present invention. If a large amount of diethylene glycol units is contained, the glass transition temperature of the copolymerized polyester decreases, causing problems such as a decrease in heat resistance and coloring,
Since the heat resistance, strength, color tone, and the like of molded articles such as bottles obtained from the copolymerized polyester become poor, it is preferable to reduce the proportion of diethylene glycol units in the copolymerized polyester as much as possible. For the reasons described above, the proportion of diethylene glycol units in the copolymerized polyester is preferably less than 1.5 mol% based on the total number of moles of all structural units of the copolymerized polyester,
It is more preferable that the content be 1.4 mol% or less, and 1.3 mol% or less.
More preferably, it is set to not more than mol%.

The copolymerized polyester of the present invention has at least three carboxyl groups, hydroxyl groups and / or ester-forming groups thereof, and at least one of them has a carboxyl group or an ester-forming group thereof. The polyfunctional compound unit (III) derived from at least one kind of a certain polyfunctional compound is contained in an amount of 0.005 to 0.5 mol% based on the total number of moles of all structural units of the copolymerized polyester.
[When two or more polyfunctional compound units (III) are present, the total ratio thereof] is required.
When the proportion of the polyfunctional compound unit (III) is less than 0.005 mol%, the melt viscosity does not become sufficiently high, and the melt viscosity does not become appropriate, that is, non-Newtonian property does not occur. Is poor in moldability. In particular, when extrusion blow molding is performed, the drawdown of the parison becomes severe, and the parison is blocked or crushed, so that a hollow molded article having a good shape cannot be manufactured. Moreover, when the proportion of the polyfunctional compound unit (III) is less than 0.005 mol%,
The solid-state polymerization rate during the production of the copolymerized polyester is reduced, and the productivity of the copolymerized polyester is reduced. on the other hand,
When the proportion of the polyfunctional compound unit (III) exceeds 0.5 mol%, the crosslinked structure in the copolymerized polyester becomes too large, and a gel derived from the hypercrosslinked structure is generated. This causes troubles such as the occurrence of bumps and whitening, and impairs transparency, appearance, and tactile sensation. When the degree of polymerization of the copolymerized polyester is reduced so as not to generate a gel, the entanglement between molecules is reduced, and sufficient mechanical strength cannot be obtained. In addition, when the proportion of the polyfunctional compound unit (III) exceeds 0.5 mol%, the crystallization rate becomes too high in the production of a molded article, spherulites are formed, and the molded article is whitened. As a result, the transparency tends to decrease, and the shaping tends to be poor. In the extrusion blow molding, the blow moldability due to the crystallization of the parison becomes poor.

The proportion of the polyfunctional compound unit (III) in the copolymerized polyester is such that the melt viscosity is sufficiently high, so that melt molding such as extrusion blow molding can be performed more favorably, and whitening and improper shaping of the molded product are obtained. From the viewpoint that a molded article having more excellent mechanical strength can be obtained, and the productivity of the copolymerized polyester itself can be further increased. It is preferably in the range of 0.01 to 0.4 mol% based on the total number of moles.

The polyfunctional compound unit (III) has three or more groups of one or more selected from a carboxyl group, a hydroxyl group and an ester-forming group thereof, and at least one of them. The unit is not particularly limited as long as it is a unit derived from a polyfunctional compound which is a carboxyl group or an ester-forming group thereof, and the polyfunctional compound for deriving the polyfunctional compound unit (III) has only 3 carboxyl groups. It may be a polyfunctional compound having at least three polyfunctional compounds or a polyfunctional compound having three or more carboxyl groups and hydroxyl groups in total.

Preferred examples of the polyfunctional compound unit (III) include trimesic acid, trimellitic acid, 1,2,3-
Benzenetricarboxylic acid, pyromellitic acid, 1,4
Aromatic polycarboxylic acids such as 5,8-naphthalenetetracarboxylic acid; 4-hydroxyisophthalic acid, 3-hydroxyisophthalic acid, 2,3-dihydroxybenzoic acid, 2,
Aromatic hydroxycarboxylic acids such as 4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, protocatechuic acid, gallic acid, 2,4-dihydroxyphenylacetic acid; fats such as tartaric acid and malic acid Group hydroxycarboxylic acids; and polyfunctional compound units derived from ester-forming derivatives thereof. The copolymerized polyester of the present invention may have, as the polyfunctional compound unit (III), one of the above-mentioned polyfunctional compound units.
It may have only one kind or two or more kinds.

Among the above, the copolymerized polyester of the present invention may comprise, as the polyfunctional compound unit (III), one or two of the polyfunctional compound units derived from trimellitic acid, pyromellitic acid and trimesic acid. Having the above is preferable from the viewpoint of easiness of production of the copolymerized polyester and the production cost, and from the viewpoint of suppressing gelation, a trimellitic acid unit and a trimesic acid unit are more preferable.

The copolymerized polyester of the present invention can contain copolymerized units other than the above-mentioned structural units as long as the physical properties thereof are not impaired (usually 3 mol% or less based on all structural units). . Examples of the copolymerized unit include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, biphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, sodium sulfoisophthalate, and 2,6-naphthalenedicarboxylic acid. Acids; aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, azelaic acid and sebacic acid; alicyclic dicarboxylic acids such as decalin dicarboxylic acid and cyclohexanedicarboxylic acid; trimethylene glycol;
Aliphatic diols such as tetramethylene glycol, hexamethylene glycol, and neopentyl glycol; and hydroxycarboxylic acids such as glycolic acid, hydroxyacrylic acid, hydroxypropionic acid, asiatic acid, quinobaic acid, hydroxybenzoic acid, mandelic acid, and matrolactic acid Acid; structural units derived from aliphatic lactones such as ε-caprolactone.

The intrinsic viscosity of the copolymerized polyester of the present invention is from 1.0 to 1.4 dl / min in view of the mechanical strength and appearance of the obtained molded article, moldability and productivity during production of the molded article.
It must be in the range of g. In particular, when extrusion blow molding is performed, if the intrinsic viscosity of the copolymerized polyester is less than 1.0 dl / g, the drawdown of the parison becomes large during extrusion blow molding, which tends to result in molding failure. Mechanical strength tends to decrease.
On the other hand, when molding accompanied by melt extrusion, particularly extrusion blow molding, the intrinsic viscosity of the copolymerized polyester is 1.4 dl /
When it is larger than g, the melt viscosity becomes too high, and a weld line is liable to be formed in the molded product at the time of melt extrusion, particularly at the time of extrusion blow molding, and the appearance of the obtained molded product tends to be poor. , A molding problem such as an uneven extrusion amount is likely to occur. The intrinsic viscosity of the copolymerized polyester is 1.4.
When it is larger than dl / g, the time required for extruding a predetermined amount of the copolyester becomes longer, and the productivity of the molded product is liable to decrease. The intrinsic viscosity of the copolymerized polyester,
The above relationship between the moldability of the copolymerized polyester and the physical properties of the molded product obtained therefrom is particularly conspicuous in extrusion blow molding, but is not limited to extrusion blow molding, and is not limited to extrusion blow molding and injection / extrusion blow molding. Almost the same tendency occurs in melt molding involving extrusion.

Further, the copolymerized polyester of the present invention has the following properties:
The melt viscosity (η1) at a shear rate of 0.1 rad / sec at a temperature of 70 ° C. is preferably 5 × 10 ^{4 to} 5 × 10 ⁶ poise. When the melt viscosity (η1) of the copolymerized polyester satisfies the above condition, curling back is particularly unlikely to occur during melt molding such as extrusion blow molding, and the occurrence of molding defects is almost completely eliminated. And melt fracture (melt fracture) during melt extrusion and die swell (die swell).
The phenomenon 1) is remarkably suppressed, and a molded article having particularly excellent appearance and uniformity can be obtained.

Further, the copolymerized polyester of the present invention comprises 2
The melt viscosity (η2) at a shear rate of 100 rad / sec at a temperature of 70 ° C. is preferably 5 × 10 ^{3 to} 5 × 10 ⁵ poise, and the melt viscosity (η2) of the copolymerized polyester satisfies the above conditions. When melt molding such as extrusion blow molding is used, deformation of the extrudate in a softened state such as a parison due to drawdown or sagging can be prevented smoothly, productivity is increased, and copolymerization is improved. It is possible to smoothly prevent the thermal decomposition of polyester, the occurrence of extrusion unevenness at the time of extrusion, and the occurrence of weld lines.

And, the copolymerized polyester of the present invention is
Shear rate 0.1 rad at a temperature of 270 ° C. as described above.
/ Melt viscosity (η 1) and melt viscosity (η 1 at a shear rate of 100 rad / sec at a temperature of 270 ° C.
In addition to the requirement of 2), the melt viscosity (η1) and the melt viscosity (η2) are determined by the following formula (α): −0.7 ≦ (１ ／) log ₁₀ (η2 / η1) ≦ −0.2 (α Is more preferably satisfied. When the above formula (α) is satisfied, the copolyester exhibits a moderate non-Newtonian property, exhibits a moderately low melt viscosity at a high shear rate, and has a moderately high melt viscosity at a low shear rate. In particular, when performing extrusion blow molding or injection / extrusion blow molding, the parison formability becomes extremely good.

In order to improve the parison forming property, the (、) log in the above formula (α) was used.
More preferably, the value of ₁₀ (η2 / η1) is in the range of -0.60 to -0.25. In the above formula (α), (1/3) log ₁₀ (η2 / η1) is the melt viscosity (η1) and the melt viscosity in a natural logarithmic graph with the melt viscosity on the vertical axis and the shear rate on the horizontal axis. It is obtained as the slope of a straight line connecting the two points of viscosity (η2). In addition, the values of the melt viscosity (η1) and the melt viscosity (η2) referred to in the present specification refer to the values measured by the methods described in the following Examples.

Further, the copolymerized polyester of the present invention comprises
The Sharkskin critical shear stress (σss) at a temperature of 270 ° C. is 1 × 10 ⁶ dyne / cm ² or more, and the shear stress (σ100) at a shear rate of 100 / sec at a temperature of 270 ° C. Shear stress (σs
It is preferably equal to or less than the value of s). The present inventors have found that the shear stress of the copolyester at the time of melt molding is also closely related to the above-mentioned surface roughness of the obtained molded article. Sharkskin critical shear stress (σss) at 270 ° C. of the copolyester is 1 × 10 ⁶ dyne / c
and m ² or more, and the shear stress at a shear rate of 100 / sec at a temperature of 270 ℃ (σ100) is less than the value of sharkskin critical shear stress (σss), when performing the melt molding such as extrusion blow molding In addition, it is possible to obtain a molded article in which the phenomenon of surface roughness is remarkably suppressed, and the appearance and touch feeling such as transparency are particularly excellent. This is presumed to be due to the fact that remarkable release of elastic normal stress between the copolyester melt and the die of the extruder is suppressed in the copolyester having the shear stress as described above. . In addition, the shark skin critical shear stress (σss) and the shear rate of 100 /
The shear stress per second (σ100) refers to the shear stress when extruded into a strand shape using a capillary nozzle with a capillary graph, the details of which are as described in the Examples section below.

The glass transition temperature of the copolymerized polyester of the present invention is preferably 60 ° C. or higher. 70 ° C transition temperature
More preferably. When the glass transition temperature of the copolymerized polyester is less than 60 ° C., after the molded article, particularly the extrusion blow molded article is taken out from the mold, the molded article undergoes shrinkage due to relaxation of the residual stress, thereby impairing the appearance of the molded article. Sometimes.

The copolyester of the present invention preferably has a terminal carboxyl group concentration of 30 μeq / g or less, and is used for the melt stability of the polyester, the prevention of discoloration, and the suppression of the wall roughness of the hollow molded article in extrusion blow molding. From the viewpoint, the terminal carboxyl group concentration is more preferably 20 μeq / g or less. When the terminal carboxyl group concentration of the copolymerized polyester exceeds 30 μeq / g, the coloring of a molded product, particularly an extrusion blow molded product, becomes remarkable, and the molecular weight is remarkably reduced.

The copolymerized polyester of the present invention can be prepared from a melt flow rate (270 ° C.) at a temperature of 270 ° C. from the viewpoints of moldability at the time of melt molding such as extrusion blow molding, uniformity of the obtained molded article, and productivity at the time of molding. Hereinafter, may be abbreviated as “MFR”), preferably in the range of 0.3 to 7.5 g / 10 min, more preferably in the range of 0.5 to 5 g / 10 min.

The copolymerized polyester of the present invention is
Preferably, the degree of crystallinity is from 20 to 40%. If the crystallinity of the copolymerized polyester is less than 20%, sticking between pellets and chips is liable to occur during solid phase polymerization, making it difficult for solid phase polymerization to be carried out smoothly and causing a decrease in productivity. In addition, blocking occurs between the copolyester pellets and chips during molding, and molding is difficult to perform smoothly. On the other hand, the crystallinity of the copolymerized polyester is 4
If it exceeds 0%, the meltability of the pellets and chips becomes poor, the resin squeals during molding (sound is generated due to friction between the pellets and chips), and the load on the molding machine is increased due to an increase in torque. Molding is difficult to be performed smoothly, and unmelted bumps are formed on the molded product, which is likely to cause defects such as transparency, appearance, and tactile sensation. Solid phase polymerization can be performed smoothly to increase the productivity of the copolymerized polyester, and in order to smoothly perform melt molding to obtain a molded product of good quality, the crystallinity of the copolymerized polyester is 25 to More preferably, it is in the range of 35%.

The copolymerized polyester of the present invention preferably has a cold crystallization temperature of 150 ° C. or less and a heat of crystallization in cold crystallization of 20 J / g or less. When the cold crystallization temperature is higher than 150 ° C., or when the heat of crystallization in cold crystallization exceeds 20 J / g, the growth rate of spherulites is increased, and the resulting molded product is whitened. It tends to be poor in transparency. Further, when extrusion blow molding is performed, solidification of the parison occurs at an early stage, and shaping tends to be difficult. In order to sufficiently delay the spherulite generation rate during melt molding and obtain a molded article having excellent transparency with good shapeability, the cold crystallization temperature of the copolymerized polyester is 140 ° C or less, and More preferably, the heat of crystallization in crystallization is 15 J / g or less. Here, the cold crystallization temperature and the heat of crystallization in cold crystallization refer to values measured by differential thermal analysis (DSC), and the details thereof are as described in the following Examples.

As described above, the copolymerized polyester of the present invention comprises: (1) (i) terephthalic acid or an ester-forming derivative thereof; (ii) ethylene glycol; (iii) diol unit (I) and / or diol unit. At least one diol selected from the above-mentioned diols (IV), diols (V) and their ester-forming derivatives for introducing (II) into the copolymerized polyester;
Functional compound; and (iv) polyfunctional compound unit (III)
Having at least three carboxyl groups, hydroxyl groups and / or their ester-forming groups for introducing the above into the copolymerized polyester, and at least one of them has a carboxyl group or its ester-forming group. Wherein the content of the bifunctional compound in the reaction material is diol unit (I) derived from the bifunctional compound.
And / or the proportion of the diol unit (II) is from 0.5 to 0.5 based on the total number of moles of all the structural units of the copolymerized polyester.
The amount of the polyfunctional compound in the reaction raw material is the proportion of the polyfunctional compound unit (III) derived from the polyfunctional compound, and the total structural units of the copolymerized polyester. A reaction raw material in an amount of 0.005 to 0.5 mol% based on the total number of moles is subjected to an esterification reaction or a transesterification reaction, and then melt-polymerized to form a polyester prepolymer. [2] By subjecting the polyester prepolymer obtained in the above step (1) to solid phase polymerization;

In the above method for producing a copolyester, a bifunctional compound and / or a polyfunctional compound are introduced to introduce a diol unit (I) and / or a diol unit (II) into the copolyester. Each of the compounds described above can be used as a polyfunctional compound for introducing the polyfunctional compound unit (III).

In producing the copolymerized polyester,
The molar ratio of (total diol component) :( total dicarboxylic acid component) should be 1.1: 1 to 1.5: 1, and the molar ratio of (polyfunctional compound component) :( total dicarboxylic acid component) should be 0. .0
It is preferable to mix the reaction components so that the ratio becomes 001: 1 to 0.01: 1, and to carry out an esterification reaction or a transesterification reaction.

The above esterification reaction or transesterification reaction is usually carried out at normal pressure or at an absolute pressure of about 3 kg / cm ^2.
It is preferable to carry out under the following pressure at a temperature of 230 to 300 ° C. while distilling off generated water or alcohol. Then, subsequently, after adding additives such as a polymerization catalyst and a coloring inhibitor as necessary, a polyester prepolymer having a desired viscosity is obtained at a temperature of 200 to 300 ° C. under reduced pressure of 5 mmHg or less. Melt polymerization is performed until a polyester prepolymer is formed. In this case, the intrinsic viscosity of the polyester prepolymer is 0.40 to 0.75 from the viewpoint of handleability of the polyester prepolymer.
dl / g, and its MFR
Is preferably 15.0 g / 10 min or more.

When a polymerization catalyst is used in the above-mentioned melt polymerization reaction, those usually used for the production of polyester can be used. For example, antimony compounds such as antimony oxide; germanium compounds such as germanium oxide; Titanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium; di-n-butyltin diurarate, di-n-butyltin oxide, dibutyltin diacetate Tin compounds and the like can be mentioned, and these catalyst compounds may be used alone or in combination of two or more. The amount of the polymerization catalyst used is 0.00% based on the weight of the dicarboxylic acid component.
Preferably it is in the range of 2 to 0.8% by weight.

When a coloring inhibitor is used, for example, phosphorous acid, phosphoric acid, trimethyl phosphite, triphenyl phosphite, tridecyl phosphite, trimethyl phosphate, tridecyl phosphate, triphenyl phosphate These phosphorus compounds may be used alone or in combination of two or more. It is preferable that the amount of the coloring inhibitor composed of the phosphorus compound be in the range of 0.001 to 0.5% by weight based on the weight of the dicarboxylic acid component. Further, in order to suppress coloring due to thermal decomposition of the copolymerized polyester, a cobalt compound such as cobalt acetate is used in an amount of 0.001 to 0.
It is preferably added in an amount of 5% by weight, more preferably 0.05 to 0.3% by weight.

Further, as described above, when a large amount of diethylene glycol units is contained in the copolymerized polyester, the glass transition temperature of the copolymerized polyester is lowered, and accordingly, heat resistance is reduced and coloring is caused. Although the heat resistance, strength, color tone, etc. of the molded article such as the above become poor, the above-mentioned esterification reaction, transesterification reaction and / or melt polymerization reaction is carried out by tetraalkylammonium hydroxide such as tetraethylammonium hydroxide; It is preferable to perform the reaction in the presence of a diethylene glycol by-product inhibitor composed of an organic amine such as ethanolamine or triethylamine, since the proportion of diethylene glycol units in the copolymerized polyester can be reduced.

Then, the polyester prepolymer obtained by the above-mentioned melt polymerization reaction is formed into chips or pellets having an arbitrary shape such as a dice, a column, and the like.
After preliminary drying at a temperature of 0 ° C. or less, its intrinsic viscosity, MF
Solid phase polymerization is carried out until R or the like becomes a desired value to form a desired copolymerized polyester. The solid phase polymerization is preferably performed under vacuum, reduced pressure, or in an inert gas such as nitrogen gas. Further, it is preferable to carry out the solid-phase polymerization while flowing the chips and pellets by an appropriate method such as a tumbling method and a gas fluidized bed method so that the chips and pellets of the polyester prepolymer do not adhere to each other. The solid phase polymerization is preferably carried out at a temperature usually in the range of 180 to 240 ° C,
It is more preferable to carry out at a temperature in the range of 190 to 230 ° C. Further, the temperature of the solid-phase polymerization is a temperature within the above-mentioned range from the viewpoint of preventing sticking between chips and pellets, and furthermore, the copolymerized polyester intended for production (copolymerized polyester finally obtained). 1 from the melting point of
The temperature may be lower than 5 ° C., preferably lower than 20 ° C. The polymerization time is usually preferably in the range of about 5 to 40 hours from the viewpoint of productivity and the like. Then, by performing the series of reactions described above, the copolymerized polyester of the present invention can be produced in a short time and with high productivity.

The copolymerized polyester of the present invention is excellent in melt moldability, transparency, heat resistance, mechanical properties, etc., and is therefore used in extrusion blow molding, injection / extrusion blow molding, extrusion molding, and injection molding. It can be molded into various molded articles by other melt molding methods. Among them, the copolymerized polyester of the present invention is suitable for use in molding involving a melt extrusion step, and particularly suitable for use in extrusion blow molding. And, the melt molding using the copolymerized polyester of the present invention, especially extrusion blow molding involving melt extrusion,
In the case of injection / extrusion blow molding, extrusion molding, injection molding, etc., it can be manufactured with good productivity without causing deformation after extrusion, and the resulting molded product has dimensional accuracy, Excellent in various properties such as transparency, heat resistance, moisture resistance and chemical resistance. In particular, when extrusion blow molding is performed using the copolymerized polyester of the present invention, the extruded parison has a good drawdown property, and the drawdown time of the parison is kept in an appropriate range. The diameter becomes uniform, the blow moldability is good,
Without causing trouble during molding, it is possible to produce a hollow molded product having a good shape and dimensional accuracy without distortion or deformation smoothly and with good productivity. It has excellent properties such as impact resistance, heat resistance, moisture resistance, and chemical resistance.

In carrying out melt molding using the copolymerized polyester of the present invention, various melt molding methods conventionally known for thermoplastic resins, for example, extrusion blow molding, injection / extrusion blow molding, What is necessary is just to carry out according to an extrusion molding method and an injection molding method, and the specific molding content is not specifically limited. In particular, when extrusion blow molding is performed using the copolymerized polyester of the present invention, the type of the extrusion blow molding method is not particularly limited, and like the conventionally known extrusion blow molding method, for example, the copolymerized polyester of the present invention is used. Is melt-extruded to form a cylindrical parison, which is inserted into a blow mold while the parison is in a softened state, and gas such as air is blown into the parison to a predetermined shape along the shape of the mold cavity. It can be performed by a method of expanding into a hollow shape. When extrusion blow molding is performed by the above-described method, the melt extrusion temperature is set to a temperature within the range of (melting point of copolymerized polyester + 10 ° C.) to (melting point of copolymerized polyester + 70 ° C.). It is preferable from the point of view.

The shape and structure of the molded article of the present invention are not particularly limited. For example, hollow molded articles, tubular bodies, plates, sheets, films, rods, molds, etc. And any dimensions and the like are not limited at all. Among them,
The present invention is particularly suitable for a hollow molded article formed by extrusion blow molding.

Further, the molded article obtained from the copolymerized polyester of the present invention, even if formed solely of the copolymerized polyester of the present invention, may be a laminate with another material such as another plastic, metal, fiber or cloth. Or a molded article having a form other than the laminated structure of the copolymerized polyester of the present invention and the above-mentioned other materials, and is not limited at all. In particular, when the molded article of the present invention is an extrusion blow molded article, for example, a single-layer hollow molded article composed of only the copolymerized polyester of the present invention (such as a hollow container), the copolymerized polyester of the present invention and polyethylene, polypropylene,
It can be a multi-layer hollow molded article with another plastic such as an ethylene-vinyl alcohol copolymer or polyethylene terephthalate (PET). Layer bottle, PET layer / copolyester layer / PET
And a five-layer bottle consisting of a layer / copolyester layer / PET layer. However, the molded article of the present invention is, of course, not limited to the above.

If necessary, the copolyester of the present invention may contain various additives conventionally used for other thermoplastic resins and polyester resins, for example, coloring agents such as dyes and pigments. Stabilizers such as UV absorbers,
An antistatic agent, a flame retardant, a flame retardant auxiliary, a lubricant, a plasticizer, an inorganic filler, and the like may be blended.

[0073]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited thereto. In the following examples, the content of each structural unit of the polyester (copolymerized polyester or homopolymerized polyester) and the physical properties of the polyester were measured, and the drawdown and blow moldability of the parison during extrusion blow molding of the polyester were evaluated. The evaluation of the transparency, the rate of occurrence of gel substances and the occurrence of lumps of the molded article (bottle) obtained by blow molding, the measurement of the drop breaking height of the molded article (bottle) and the evaluation of the drop impact strength are as follows. I went.

(1) Content of each structural unit in polyester: The polyester was subjected to methanolysis, and its constituent components were separated using high performance liquid chromatography. Quantitative analysis by spectrum (IR) was performed to determine the content of each structural unit. Further, it was confirmed by a ¹ H-NMR spectrum of a polyester using deuterated trifluoroacetic acid as a solvent.

(2) Intrinsic viscosity of polyester: 30 ° C. in an equal weight mixed solvent of phenol and tetrachloroethane
Udelode viscometer (“HRK-3” manufactured by Hayashi Seisakusho)
Mold ").

(3) Melt flow rate (MFR) of prepolymer and polyester: Melt indexer L
244 (manufactured by Takara Industry Co., Ltd.). Specifically, prepolymer or polyester (final product)
Was filled into a cylinder having an inner diameter of 9.55 mm and a length of 162 mm, and was melted at 270 ° C. (However, in Comparative Examples 6 and 10, since the copolymerized polyester was amorphous, it was heated at 210 ° C.) 2160 g, based on the weight of the molten prepolymer or polyester,
A uniform load was applied by a plunger having a diameter of 9.48 mm, and the outflow rate (g / 10 minutes) of the prepolymer or polyester extruded from an orifice having a diameter of 2.1 mm provided in the center of the cylinder was measured. Flow rate was used.

(4) Melt viscosity of polyester (η1 and η2): Using a parallel plate with a mechanical spectrometer (“RMS-800” manufactured by Rheometrics), the shear rate of the polyester at a temperature of 270 ° C. 0.1 rad. The melt viscosity (η1) (poise) at 270 ° C./sec and the melt viscosity (η2) (poise) at a shear rate of 100 rad / sec at a temperature of 270 ° C. of the polyester were dynamically measured (however, Comparative Examples 6 and In the case of Comparative Example 10, it was measured at 210 ° C. because the copolymerized polyester was amorphous.)

(5) Sharkskin critical shear stress (σss) and shear stress (σ100) of polyester: 2 mm in diameter × 10 m in length by Capillograph (manufactured by Toyo Seiki)
The polyester was extruded into strands at a temperature of 270 ° C. with a varying shear rate using a capillary nozzle of m. The shear stress at the time when the strand surface was roughened (when the ten-point average surface roughness became 1.5 μmRz or more) was determined, and this was used as the critical shear stress (σss) (dyne / cm ² ) for shark skin (shark skin). ). Further, using the same apparatus, the shear stress (σ100) of the polyester at a temperature of 270 ° C. at a shear rate of 100 / sec.
(Dyne / cm ² ) was measured (however, in the case of Comparative Examples 6 and 10, it was measured at 210 ° C. because the copolymerized polyester was amorphous).

(6) Crystallinity of polyester (Δc):
The density (d) (25 ° C.) of the polyester was measured, and the density (d) of a completely amorphous PET (polyethylene terephthalate) was measured.
a) is set to 1.335, the density (dc) of fully crystallized PET (polyethylene terephthalate) is set to 1.501, and the crystallinity (χc) of the polyester is obtained from the following formula (β).
I asked.

{C (%) = {dc (d−da) / d (dc−da)} × 100 (β)

(7) Glass transition temperature of polyester (T
g) and melting point (Tm): According to JIS K7121 by differential thermal analysis (DSC) using a thermal analysis system “Mettler TA3000” (manufactured by METTLER CORPORATION).
The measurement was performed under the condition of a heating rate of 10 ° C./min.

(8) Cold crystallization temperature of polyester (Tc)
c) and heat of cold crystallization (ΔHcc): JIS K71
According to the differential thermal analysis method (DSC), using a thermal analysis system “Mettler TA3000” (manufactured by Mettler), the temperature was maintained at a temperature of melting point + 40 ° C. for 5 minutes, and then the temperature was lowered at a rate of 5 ° C./min. Was measured.

(9) Concentration of terminal carboxyl groups (CEG) of polyester: 0.2 g of polyester was dissolved in 10 ml of benzyl alcohol heated at 215 ° C., 10 ml of chloroform was added to the solution, and titration was performed using benzyl alcoholic sodium hydroxide. did.

(10) Drawdown property of parison during extrusion blow molding: (i) Drawdown time of parison (second) Extrusion blow molding apparatus manufactured by Placo Co., Ltd. (hollow molding machine “BM-304.J2 type machine”) ) To form a cylindrical parison at an extrusion temperature of 270 ° C. at an extrusion rate of about 25 kg / hour (except that the copolymerized polyester is amorphous in Comparative Examples 6 and 10). Because of this, it was molded at an extrusion temperature of 210 ° C.), while the cylindrical parison was in a softened state, cutting and bottom formation were carried out by sandwiching it with a blow mold, and this was blow molded to set a capacity of 1800 ml and a set weight of 80. Grams of soft drink bottles were produced. The above-mentioned extrusion blow molding apparatus used here is designed so that when the parison is drawn down by 35 cm, it is picked up by a mold and blown, and therefore, the time required for drawing down by 35 cm (seconds).
Was measured as the drawdown time. In the case of the extrusion blow molding apparatus used here, the moldability is good when the drawdown time is in the range of 15 to 25 seconds. If the draw-down time is less than 15 seconds, the draw-down is severe and the parison shape becomes uneven, resulting in a defective product with large uneven thickness after blow, inability to insert into the blow mold, blockage in the parison hollow part, etc. Occurs. On the other hand, if the drawdown time exceeds 25 seconds, the productivity of the molded product (bottle) decreases, and the melt viscosity of the polyester is too high to allow uniform blowing, and furthermore, the non-adhesion at the pinch-off portion of the bottle In addition, the occurrence of weld lines, breakage of the molding apparatus due to an increase in torque, and the like are likely to occur.

(Ii) Difference between the maximum diameter (outside diameter) and the minimum diameter (outside diameter) of the parison: A cylindrical parison is extruded at an extrusion temperature of 270 ° C. using the above extrusion blow molding apparatus (provided that:
In the case of Comparative Example 6 and Comparative Example 10, the copolymerized polyester was amorphous and was molded at an extrusion temperature of 210 ° C.), and when the parison reached 35 cm, the maximum diameter (outer diameter) and the minimum diameter of the parison (Outer diameter) was measured, and their difference was determined. The diameter of the annular die of the extrusion nozzle of the above-mentioned extrusion blow molding apparatus used is 3.5 cm, but the extruded parison has a drawdown due to its own weight, and the diameter tends to decrease as the parison moves away from the die. When the difference between the maximum diameter and the minimum diameter of the parison is 1 cm or less, extrusion blow molding can usually be performed smoothly. On the other hand, if the difference between the maximum diameter and the minimum diameter of the parison exceeds 1 cm, unevenness in thickness occurs after blowing, resulting in a defective product.

(Iii) Comprehensive Evaluation of Drawdown of Parison: From the viewpoint of the drawdown time of the parison, the difference between the maximum diameter and the minimum diameter of the parison, and the level of productivity of the bottle, the results are shown in Table 1 below. Comprehensive drawdown evaluation was performed according to the evaluation criteria. At that time, regarding the productivity of the bottles, from the viewpoint of cost, 120 or more bottles can be produced per hour, and when the number of defective moldings is less than 10 out of 100 bottles, the productivity is considered to be good. The molding failure here means that the extruded parison cannot be inserted into the blow mold due to drawdown, the hollow part of the parison is blocked, the pinch-off portion is not adhered due to high viscosity, and the bottle shape is caused by uneven blow. It means a case where at least one of the troubles of deformation and destruction of the object occurs.

[0087]

[Table 1]

(11) Blow moldability during extrusion blow molding (i) Average wall thickness of bottle: The bottle is divided into five parts at equal intervals from the upper part to the lower part of the bottle body obtained by molding, and each is further divided into a bottle circle. It was divided into four at equal intervals in the circumferential direction, the wall thickness was measured at a total of 20 places, and the average wall thickness was calculated.
The average wall thickness is 0.3 in terms of appearance, touch, and bottle strength.
It is preferably in the range of not less than mm and not more than 0.7 mm. (Ii) Uneven thickness of the bottle: The difference (mm) between the maximum thickness and the minimum thickness in the wall thickness of the bottle body obtained in the above measurement (i) was obtained and evaluated. It is preferable that the thickness unevenness is less than 0.3 mm. If the thickness unevenness is more than 0.3 mm, an extremely thin portion and / or a broken portion is generated, resulting in poor appearance and / or tactile sensation. (Iii) Comprehensive evaluation of blow moldability Comprehensive evaluation of blow moldability was performed according to the evaluation criteria shown in Table 2 below.

[0089]

[Table 2]

(12) Transparency of bottle: (i) Haze value (cloudiness value): ASTM D1003 was obtained for a total of 24 places, which were obtained by dividing the bottle body into six parts at the upper, middle and lower parts and further dividing it into four parts on the circumference. According to the standard, a Poick integrating sphere type light transmittance / total light reflectometer (“SEP-HS.30D-R” manufactured by Nippon Seimitsu Optical Co., Ltd.)
The haze value at each location was measured using a “type”, and the average value was taken as the haze value (cloudiness value) of the bottle. When the haze value exceeds 8, transparency becomes poor due to whitening due to spherulite formation or light scattering due to gel-like particles.
The haze value is preferably 4 or less from the viewpoint of transparency. (Ii) The bottle body was cut into 1 cm ² (1 cm × 1 cm square pieces), and a color difference meter (“SM” manufactured by Suga Test Instruments Co., Ltd.)
-4 type ") by a reflection method. If the b value exceeds 8, the color tone of the bottle becomes yellowish and the appearance becomes poor. The b value is preferably 4 or less in terms of color tone. (Iii) Comprehensive evaluation of bottle transparency: Comprehensive evaluation of bottle transparency was performed according to the evaluation criteria shown in Table 3 below.

[0091]

[Table 3]

(13) Rate of occurrence of gel in bottle: 1 g of polyester in the body of the bottle was cut out and dissolved in 10 ml of hexafluoroisopropanol at 30 ° C. for 5 hours. Filtered through a 4G glass filter. After heating the gel at a temperature of 100 ° C. for 60 minutes and drying, the weight was measured, and the weight percentage based on the cut polyester sample (1 g) was determined as the gel product generation rate. The evaluation shown in Table 4 below was obtained. The evaluation of the rate of gelation of the bottle was performed according to the standard.

[0093]

[Table 4]

(14) Occurrence rate of bottle spots: The center of the bottle body was cut out at a size of 10 cm × 10 cm, and the number of spots contained therein was visually measured. The evaluation of the occurrence rate of the spots was performed.

[0095]

[Table 5]

(15) Drop impact strength of the bottles: Each of the 10 bottles obtained by molding is filled with water and covered with water so that no void remains, and each of the bottles is first placed one by one. Drop naturally from a height of 50 cm. If the bottle does not break, increase the drop height in 10 cm increments and let it fall naturally in the same manner. The average value of the height of the bottles at the time of destruction was taken as the fall-destruction height. The drop impact strength of the bottle was evaluated according to the evaluation criteria shown in Table 6 below.

[0097]

[Table 6]

Example 1 (1) 100.00 parts by weight of terephthalic acid, 48.73 parts by weight of ethylene glycol, 2,2-bis [4- (2-
A slurry comprising 9.49 parts by weight of hydroxyethoxy) phenyl] propane and 0.578 parts by weight of trimellitic anhydride was prepared, and 0.020 parts by weight of germanium dioxide, 0.015 parts by weight of phosphorous acid, .015
Parts by weight of cobalt acetate and 0.015 parts by weight of tetraethylammonium hydroxide were added. This slurry was heated to a temperature of 250 ° C. under pressure (2.5 kg / cm ² absolute pressure), and an esterification reaction was carried out until the esterification rate became 95% to produce a low polymer. Then, 1m
The low polymer is melt-polymerized at a temperature of 270 ° C. under a reduced pressure of mHg to produce a prepolymer of a copolymerized polyester having an intrinsic viscosity of 0.69 dl / g, which is extruded from a nozzle into a strand and cut. Then, a cylindrical tip (about 2.5 mm in diameter and about 3.5 mm in length) was obtained. The melt flow rate of this prepolymer at 270 ° C. is 29 g.
/ 10 minutes. (2) Next, after pre-drying the copolyester chips obtained above at 150 ° C. for 5 hours, using a tumbling vacuum solid-state polymerization apparatus, the prepolymer chips were heated at 210 ° C. under a reduced pressure of 0.1 mmHg. Was carried out for 20 hours to obtain a high molecular weight copolymerized polyester.

(3) The content of each structural unit of the copolymerized polyester obtained in the above (2) was measured by the above-mentioned method. As a result, the terephthalic acid unit, ethylene glycol unit, 2,2-bis [4- (2
-Hydroxyethoxy) phenyl] propane units, trimellitic acid units and diethylene glycol units were as shown in Table 8 below. (4) The physical properties of the copolymerized polyester obtained in the above (2) were measured by the above-mentioned methods.
As shown in the figure, the intrinsic viscosity is 1.18 dl / g,
The melt viscosity at a temperature of 0.6 g / 10 min, the melt viscosity at a shear rate of 0.1 rad / sec (η1) is 6.79 × 10 ⁵ poise, and the melt viscosity at a shear rate of 100 rad / sec (η2). Is 1.57 × 10 ⁴ poise, and the value of (1/3) log ₁₀ (η2 / η1) is −0.
55. Further, the copolyester obtained in the above (2) has a Sharkskin critical shear stress (σss) at 270 ° C. of 5.9 × 10 ⁶ dyne / cm ² and a shear stress (σ100) at a shear rate of 100 / sec. 2.9 × 10 ⁶ d
yne / cm ² . Further, Δc, Tg, Tm, Tcc and ΔHcc of the copolymerized polyester obtained in the above (2) were measured by the above-mentioned method, and the results are shown in Table 8 below.
30%, 80 ° C., 235 ° C., 13
8 ° C and 13 J / g. Further, the terminal carboxyl group concentration (CEG) of the copolymerized polyester obtained in the above (2) was 12 μeq / g.

(5) The copolymerized polyester obtained in the above (2) was subjected to extrusion blow molding by the above-mentioned method using an extrusion blow molding apparatus (“BM-304.J2 type” manufactured by Placo Co., Ltd.). A bottle having a set volume of 1800 ml and a set weight of 80 g was manufactured. At that time, the draw-down property of the parison, the blow moldability and the transparency of the obtained bottle, the rate of occurrence of gel, the rate of occurrence of lumps, the height of dropping fracture and When the drop impact strength was measured or evaluated by the above-described method, it was as shown in Table 14 below.

Examples 2 to 4 Terephthalic acid and ethylene glycol were used in the proportions shown in Table 8 below, and difunctional diol units (I) and / or diol units (II) having a benzene nucleus were used. 2,2-
Bis [4- (2-hydroxyethoxy) phenyl] propane or bis [4- (2-hydroxyethoxy) phenyl] sulfone is used as a polyfunctional compound for the polyfunctional compound unit (III) as trimellitic anhydride or pyromellitic anhydride. Using an acid in the ratio shown in Table 8, an esterification reaction and a melt polymerization reaction were carried out in the same manner as in Example 1 to produce a prepolymer chip of a copolymerized polyester, and then the temperature and time shown in Table 8 below Was performed to produce copolymerized polyesters. The content of each structural unit in the obtained copolyester and the physical properties of the copolyester were examined in the same manner as in Example 1. The results were as shown in Table 8 below. Extrusion blow molding was carried out in the same manner as in Example 1 using the copolymerized polyester obtained in each of Examples 2 to 4 to produce a bottle. The transparency of the obtained bottle, the rate of gel generation,
The occurrence rate of the bumps, the drop breaking height, and the drop impact strength were measured or evaluated by the methods described above, and the results were as shown in Table 14 below.

Example 5 Terephthalic acid and ethylene glycol were used in the proportions shown in Table 9 below and used as a bifunctional compound for a diol unit (I) and / or a diol unit (II) having a benzene nucleus. Using 1,4-bis (2-hydroxyethoxy) benzene as the polyfunctional compound for the polyfunctional compound unit (III), trimellitic anhydride in the ratio shown in Table 9, in the same manner as in Example 1,
After performing an esterification reaction and a melt polymerization reaction to produce a prepolymer chip of a copolymerized polyester, solid phase polymerization was performed at the temperature and time shown in Table 9 below to produce a copolymerized polyester, respectively. The content of each structural unit in the obtained copolymerized polyester and the physical properties of the copolymerized polyester were examined in the same manner as in Example 1, and the results were as shown in Table 9 below. In addition, the fifth embodiment
Using the copolymerized polyester obtained in the above, extrusion blow molding was carried out in the same manner as in Example 1 to produce a bottle. At that time, the drawdown property of the parison, the blow moldability and the transparency of the obtained bottle, gel The object generation rate, gross generation rate, drop breaking height and drop impact strength were measured or evaluated by the above-mentioned methods, and the results were as shown in Table 14 below.

Comparative Examples 1-4 Terephthalic acid and ethylene glycol were used in the proportions shown in Table 10 below, and with or without addition of neopentyl glycol as a bifunctional compound for a bifunctional compound unit. Or isophthalic acid as a bifunctional compound for the bifunctional compound unit, and trimethylolpropane, trimellitic anhydride or pentaerythritol as the polyfunctional compound for the polyfunctional compound unit (III), as shown in Table 10. And the esterification reaction and melt polymerization in the same manner as in Example 1 with or without using benzoic acid or m-anisic acid as the monofunctional compound for the monofunctional compound unit in the proportions shown in Table 10. After performing the reaction to produce a prepolymer chip of the copolymerized polyester, the following Table 1 was used.
Solid-state polymerization was carried out at a temperature and for a time indicated by 0 to produce copolymerized polyesters. The content of each structural unit in the obtained copolyester and the physical properties of the copolyester were examined in the same manner as in Example 1, and the results are shown in Table 10 below. Further, using the copolymerized polyester obtained in each of Comparative Examples 1 to 4, extrusion blow molding was performed in the same manner as in Example 1 to produce a bottle. The transparency, the gel substance generation rate, the porosity generation rate, the drop breaking height and the drop impact strength of the obtained bottle were measured or evaluated by the above-mentioned methods, and the results were as shown in Table 14 below.

Comparative Examples 5 to 8 Terephthalic acid and ethylene glycol were used in the proportions shown in Table 11 below, and difunctional diol units (I) and / or diol units (II) having a benzene nucleus were used. No compound is used, or 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane is used as a bifunctional compound for the diol unit (I) and / or the diol unit (II) having a benzene nucleus, Also polyfunctional compound unit (III)
In the same manner as in Example 1, the esterification reaction and the melting were performed in the same manner as in Example 1 except that no polyfunctional compound was used or trimellitic anhydride was used as the polyfunctional compound for the polyfunctional compound unit (III) in the ratio shown in Table 11. After performing a polymerization reaction to produce a prepolymer chip of a copolymerized polyester, the following Table 1 was used.
Solid-state polymerization was carried out at the temperature and time shown in Example 1 to produce copolymerized polyesters. (However, in Comparative Example 6, since the prepolymer chips of the copolymerized polyester were non-crystalline, the following solid-state polymerization was not performed. Used for extrusion blow molding as is). The content of each structural unit in the obtained copolyester and the physical properties of the copolyester were examined in the same manner as in Example 1, and the results were as shown in Table 11 below (provided that the comparison was made as described above). The measurement was performed at 210 ° C. for Example 6). Comparative Example 5
Extrusion blow molding was carried out in the same manner as in Example 1 to produce a bottle using the copolymerized polyester obtained in each of Comparative Examples Nos. 1 to 8, and the drawdown properties of the parison, the blow moldability, and the transparency of the resulting bottle When the properties, the gel substance generation rate, the spotting rate, the drop breaking height and the drop impact strength were measured or evaluated by the above-described methods, the results were as shown in Table 14 below (however, as described above, the comparative example For No. 6, extrusion blow molding was performed at 210 ° C.).

<< Comparative Examples 9 and 10 >> Terephthalic acid and ethylene glycol were used in the proportions shown in Table 12 below, and further used for diol units (I) and / or diol units (II) having a benzene nucleus. 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane was used as the bifunctional compound, and trimellitic anhydride was used as the polyfunctional compound for the polyfunctional compound unit (III). After the esterification reaction and the melt polymerization reaction were carried out in the same manner as in Example 1 to prepare a prepolymer chip of a copolymerized polyester, with or without using the above, the solid phase was obtained at the temperature and time shown in Table 12 below. Polymerization was carried out to produce copolyesters (however, in Comparative Example 10, the prepolymer chips of the copolyester were amorphous and It was used) in the extrusion blow molding below without solid state polymerization because of Tsu. The content of each structural unit in the obtained copolyester and the physical properties of the copolyester were examined in the same manner as in Example 1 and the results were as shown in Table 12 below (however, the comparison was made as described above). The measurement was performed at 210 ° C. for Example 10). Extrusion blow molding was carried out using the copolymerized polyesters obtained in Comparative Examples 9 and 10, respectively, in the same manner as in Example 1 to produce bottles. When the properties and the transparency of the obtained bottle, the rate of occurrence of gel substances, the rate of occurrence of lumps, the drop breaking height and the drop impact strength were measured or evaluated by the methods described above, the results were as shown in Table 14 below ( However, as described above, in Comparative Example 10
Extrusion blow molding at 0 ° C.).

Comparative Example 11 (1) A slurry comprising 100.00 parts by weight of dimethyl terephthalate and 80.12 parts by weight of ethylene glycol was prepared, and 0.032 parts by weight of manganese acetate was added thereto. The slurry is heated at 190 ° C for 2 hours at 210 ° C.
For 2 hours under a nitrogen stream. During this time, methanol was continuously distilled off to produce a low polymer. Next, 26.12 parts by weight of bis [4- (2-hydroxyethoxy) phenyl] sulfone, 0.989 parts by weight of trimellitic anhydride, 0.038 parts by weight of antimony trioxide and 0 of triphenylphosphite were added to the low polymer. 0.077 parts by weight, tetrakis [2,4-di-tert-butylphenyl] 4,4′-
Add 0.031 parts by weight of biphenylenediphosphonite,
The reaction temperature was raised to 260C. One hour and 20 minutes later, the nitrogen gas flow was stopped, and then 275 ° C. under a reduced pressure of 0.4 mmHg.
Is melt polymerized at a temperature of to produce a copolymerized polyester having an intrinsic viscosity of 1.08 dl / g, which is extruded into a strand shape from a nozzle and cut into a cylindrical chip (about 2.5 mm in diameter). , Length about 3.5 mm).

(2) The content of each structural unit of the copolymerized polyester obtained in the above (1) was measured by the above-mentioned method. [2-Hydroxyethoxy) phenyl] sulfone unit, trimellitic acid unit and diethylene glycol unit content were as shown in Table 13 below. (3) The physical properties of the copolymerized polyester obtained in the above (1) were measured by the methods described above.
As shown in FIG. 3, the MFR at a temperature of 270 ° C. was 0.3.
2 g / 10 min, shear rate 0.1 rad /
The melt viscosity in seconds (η1) is 2.76 × 10 ⁶ poise, and the melt viscosity (η2) at a shear rate of 100 rad / sec is 1.89.
× 10 ⁴ poises and therefore (１ ／) log ₁₀
The value of (η2 / η1) was -0.72. Further, the sharkskin critical shear stress (σss) at 270 ° C. of the copolymerized polyester obtained in the above (1) is 3.5 × 10
The shear stress (σ100) at a shear rate of ⁶ dyne / cm ² and a shear rate of 100 / sec was 3.8 × 10 ⁶ dyne / cm ² .
Further, the copolymer polyester obtained in the above (1)
When c, Tg, Tm, Tcc and ΔHcc were measured by the above-described method, as shown in Table 13 below, Δc, Tc
g and Tm are 8%, 86 ° C. and 212 ° C., respectively.
Both cc and ΔHcc were not detected. further,
The terminal carboxyl group concentration (CEG) of the copolymerized polyester obtained in the above (1) was 32 μeq / g.

(5) The copolymerized polyester obtained in the above (1) was subjected to extrusion blow molding by the above-mentioned method using an extrusion blow molding apparatus (“BM-304.J2 type” manufactured by Placo Co., Ltd.). A bottle having a set volume of 1800 ml and a set weight of 80 g was manufactured. At that time, the draw-down property of the parison, the blow moldability and the transparency of the obtained bottle, the rate of occurrence of gel, the rate of occurrence of lumps, the height of dropping fracture and When the drop impact strength was measured or evaluated by the above-described method, it was as shown in Table 14 below.

<< Comparative Examples 12 and 13 >> Terephthalic acid and ethylene glycol were used in the proportions shown in Table 13 below, and were used for diol units (I) and / or diol units (II) having a benzene nucleus. Bis [4- (2-hydroxyethoxy) phenyl] sulfone is used as a bifunctional compound, and a polyfunctional compound unit (III)
An esterification reaction and a melt polymerization reaction were carried out in the same manner as in Comparative Example 11 using trimellitic anhydride as the polyfunctional compound for use in the proportions shown in Table 13 to produce a copolymerized polyester. The content of each structural unit in the obtained copolyester and the physical properties of the copolyester were examined in the same manner as in Example 1, and the results were as shown in Table 13 below. Further, Comparative Example 12 and Comparative Example 1
Extrusion blow molding was carried out in the same manner as in Example 1 using the copolymerized polyester obtained in Example 3 to produce a bottle. At that time, the drawdown property of the parison, the blow moldability, and the transparency of the obtained bottle, The rate of occurrence of the gel substance, the rate of occurrence of the lumps, the drop breaking height and the drop impact strength were measured or evaluated by the above-mentioned methods, and the results were as shown in Table 14 below.

Comparative Example 14 (1) 100.00 parts by weight of dimethyl terephthalate, 79.90 parts by weight of ethylene glycol, 2,2-bis [4
-(2-hydroxyethoxy) phenyl] propane8.
A slurry consisting of 144 parts by weight and 0.035 parts by weight of pentaerythritol was prepared, and 0.010 parts by weight of zinc dust was added thereto. The slurry was heated at 190 ° C. for 2 hours, 210 ° C. for 2 hours, and 240 ° C. for 2 hours under a nitrogen stream. During this time, methanol was continuously distilled off to produce a low polymer. Next, 0.038 parts by weight of antimony trioxide and 0.0 of triphenyl phosphite were added to the low polymer.
77 parts by weight, tetrakis [2,4-di-tert-butylphenyl] 4,4′-biphenylenediphosphonite 0.03
One part by weight was added and the reaction temperature was raised to 260 ° C. After 1 hour and 20 minutes, the low-polymer is melt-polymerized at a temperature of 270 ° C. under a reduced pressure of 0.4 mmHg after stopping the flow of the nitrogen gas to produce a copolyester having an intrinsic viscosity of 0.70 dl / g. This was extruded into a strand shape from a nozzle and cut, and a cylindrical tip (diameter: about 2.5 mm, length: about 3.
5 mm).

(2) The content of each structural unit in the copolymerized polyester obtained in the above (1) was measured by the above-mentioned method. [4- (2
-Hydroxyethoxy) phenyl] propane units, pentaerythritol units and diethylene glycol units were as shown in Table 13 below. (3) The physical properties of the copolymerized polyester obtained in the above (1) were measured by the methods described above.
As shown in FIG. 3, the MFR at a temperature of 270 ° C. is 34.
g / 10 minutes, the melt viscosity (η1) at a shear rate of 0.1 rad / sec at the same temperature is 5.62 × 10 ³ poise, and the melt viscosity (η2) at a shear rate of 100 rad / sec is 3.17 ×.
10 ³ poise and therefore (１ ／) log
The value of ₁₀ (η2 / η1) was −0.08. Further, the sharkskin critical shear stress (σss) at 270 ° C. of the copolymerized polyester obtained in the above (1) is 5.5 × 1.
0 ⁶ dyne / cm ^2, the shear stress at a shear rate of 100 / sec (σ100) was ^{1.5 × 10 6 dyne / cm 2} .
Further, the copolymer polyester obtained in the above (1)
When c, Tg, Tm, Tcc and ΔHcc were measured by the above-described methods, they were 28%, 79 ° C., 234 ° C., 152 ° C. and 21 J / g, respectively, as shown in Table 13 below.
Met. Further, the terminal carboxyl group concentration (CEG) of the copolymerized polyester obtained in the above (1) was 33 μeq / g.

(5) The copolymerized polyester obtained in the above (1) was subjected to extrusion blow molding by the above-mentioned method using an extrusion blow molding apparatus ("BM-304.J2" manufactured by Placo Co., Ltd.). A bottle having a set volume of 1800 ml and a set weight of 80 g was manufactured. At this time, the draw-down property of the parison, the blow moldability, and the transparency, the occurrence rate of drops, the drop breaking height and the drop impact strength of the obtained bottle were determined as described above. Table 1 below shows the results of measurement or evaluation by the following methods.
As shown in FIG.

The contents of the abbreviations used in the following Tables 8 to 13 are as shown in Table 7 below.

[0114]

[Table 7]

[0115]

[Table 8]

[0116]

[Table 9]

[0117]

[Table 10]

[0118]

[Table 11]

[0119]

[Table 12]

[0120]

[Table 13]

[0121]

[Table 14]

From the results in Tables 8, 9 and 14, it can be seen that the diol unit mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus based on the total moles of all structural units of the copolymerized polyester. (I) and / or the diol unit (II) is 0.5 to
Polyfunctional compound unit (III) in the range of 7 mol%
In the case of Examples 1 to 5 in which a copolymerized polyester having a
It can be seen that a copolyester having an intrinsic viscosity suitable for melt molding such as extrusion blow molding can be produced with a short solid phase polymerization time of 0 hour or less. Moreover, when a bottle was manufactured by extrusion blow molding using the copolymerized polyester obtained in Examples 1 to 5, the drawdown time of the extruded parison was in an appropriate range of 16 to 23 seconds, and the parison minimum The difference between the value and the maximum value is 0.3 cm or less,
Bottle production is more than 120 bottles per hour,
In addition, the ratio of bottles with poor molding is less than 10 out of 100 bottles, and the parison has excellent drawdown properties,
And the average wall thickness of the obtained bottle is 0.3 mm or more.
It is within the range of 7 mm or less, and the thickness unevenness is less than 0.3 mm, which indicates that the blow moldability is excellent. In addition, the bottles obtained in Examples 1 to 5 had a haze value of 4 or less, a b value of 4 or less, excellent transparency, and a gel substance generation rate of 5% or less. It can be seen that when the occurrence rate is 5 pieces / 100 cm ² or less, the occurrence of spots is extremely small, and furthermore, the drop breaking height is 100 cm or more, and the impact strength is high.

On the other hand, Tables 10 and 14
According to the results of the above, it is mainly composed of terephthalic acid units and ethylene glycol units, but does not have a diol unit (I) and / or a diol unit (II) having a benzene nucleus, and only a polyfunctional compound unit (III) In the case of Comparative Examples 1 and 2 in which a copolyester having a polyfunctional compound unit (III) and a monofunctional compound unit is produced, the solid phase polymerization time is 40 hours or more, and the polymerization takes a long time. In short, it turns out that productivity is inferior. Moreover, when a bottle was manufactured by extrusion blow molding using the copolymerized polyester obtained in these comparative examples, the thickness unevenness of the bottle was not less than 0.30 mm, and the blow moldability was poor. The resulting bottle has a haze value of 10 or more and is poor in transparency, furthermore, the rate of occurrence of gels exceeds 5% (Comparative Example 2), and the rate of occurrence of bumps exceeds 10 pieces / 100 cm ² . It can be seen that the appearance and tactile sensation were poor and that the drop breaking height was 50 cm and the drop impact strength was small.

Further, from the results of Tables 10 and 14, it can be seen from the results that the diol unit (I) and / or diol unit (II) mainly comprising a terephthalic acid unit and an ethylene glycol unit and having a benzene nucleus are not present. Alternatively, in the case of Comparative Example 3 in which a copolymerized polyester having a neopentyl glycol unit as a bifunctional compound unit and a trimethylolpropane unit as a polyfunctional compound unit (III) is produced, Solid phase polymerization time 3
It was found that the time was longer than 0 hours, a long time was required for polymerization, and the productivity was poor. Moreover, when a bottle was manufactured by extrusion blow molding using the copolymerized polyester obtained in Comparative Example 3, the thickness unevenness of the bottle was not less than 0.30 mm and the blow moldability was poor. Has a haze value of more than 4 and is inferior in transparency, furthermore, the rate of occurrence of gels exceeds 5%, and the rate of occurrence of bumps exceeds 10/100 cm ² ,
Poor appearance and tactile sensation, and a drop breaking height of 8
It is clear that the drop impact strength is small at 0 cm.

Further, from the results in Tables 10 and 14, it is found that the diol unit (I) mainly comprising a terephthalic acid unit and an ethylene glycol unit and having a benzene nucleus.
And / or does not have a diol unit (II), but instead has an isophthalic acid unit as a bifunctional compound unit, has a pentaerythritol unit as a polyfunctional compound unit (III), and is a monofunctional compound. M-
The copolymerized polyester of Comparative Example 4 having an anisic acid unit had a thickness unevenness of 0.45 mm when the bottle was manufactured by extrusion blow molding, and was inferior in blow moldability. Has a remarkably rough surface, has a haze value of 8.5, is inferior in transparency, and is inferior in tactile sensation. Moreover, Comparative Example 4
It can be seen that the bottle obtained by using the copolymerized polyester has a drop breaking height of 50 cm, a small drop impact strength, and low quality.

From the results shown in Tables 11 and 14, the polyester produced using only terephthalic acid and ethylene glycol and having a diol unit (I) and / or a diol unit (II) having a benzene nucleus.
And the copolymerized polyester of Comparative Example 5 having no polyfunctional compound unit (III) (the polyester of Comparative Example 5 has the above-mentioned undesired copolymerized unit of diethylene glycol unit as 1. Has a drawdown time of 5 seconds for the parison, and the difference between the parison's maximum and minimum diameter is 3.
0 cm or more, the drawdown property of the parison is remarkably inferior, and it can be seen that extrusion blow molding is actually difficult. In the case of Comparative Example 5, 6
It took seven hours, indicating that the productivity was extremely low.

Further, from the results in Tables 11 and 14, it can be seen that diol units (I) and / or diol units (II) mainly comprising terephthalic acid units and ethylene glycol units and having a benzene nucleus are contained. The copolymerized polyester of Comparative Example 6, the ratio of which exceeds 7 mol% based on the total number of moles of all structural units of the copolymerized polyester, was amorphous and could not increase the degree of polymerization by solid-phase polymerization. Extrusion blow molding could not be performed because a high melt viscosity was not obtained at a temperature of 270 ° C. Therefore, extrusion blow molding was performed at a temperature of 210 ° C., which was barely possible. When the bottle was manufactured by extrusion blow molding, the thickness unevenness of the bottle was 0.45 mm and the blow moldability was poor. It is seen. In addition, the bottle obtained in Comparative Example 6 was extremely low in surface roughness due to molding at a low temperature, and therefore had a haze value of more than 8 and was inferior in transparency, and was also inferior in tactile sensation. In addition, the drop breaking height is 50 cm, the drop impact strength is small, and it can be seen that the quality is low.

Further, from the results of Tables 11 and 14, the diol unit (I) and / or diol unit (II) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus, and the polyfunctional compound unit ( III), but the proportion of the diol unit (I) and / or the diol unit (II) having a benzene nucleus is less than 0.5 mol% based on the total number of moles of all the structural units of the copolymerized polyester. The copolyester of Comparative Example 7 was inferior in blow moldability because the thickness unevenness of the bottle was 0.3 mm when the bottle was manufactured by extrusion blow molding, and the resulting bottle had a high crystallization rate. A haze value of 8 or more, inferior in transparency, and a drop breaking height of 80 cm, a low drop impact strength, and low quality. I understand.

Further, from the results in Tables 11 and 14, the diol unit (I) and / or diol unit (II) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus, and the polyfunctional compound unit ( Comparative Example having (III), but the proportion of the polyfunctional compound unit (III) is out of the range of the present invention and exceeds 0.5 mol% based on the total number of moles of all structural units of the copolymerized polyester. The copolyester of No. 8 had a thickness irregularity of 0.3 when the bottle was manufactured by extrusion blow molding.
5 mm, which is inferior in blow moldability, the resulting bottle has a slight roughness on the surface, has a haze value of 8 or more, is inferior in transparency, has a remarkable amount of gel and unmelted butts, and has a drop. It can be seen that the breaking height is 70 cm, the drop impact strength is low, and the quality is low.

Further, from the results of Tables 12 and 14, it can be seen that diol unit (I) and / or diol unit (II) mainly composed of terephthalic acid unit and ethylene glycol unit and having a benzene nucleus. The copolyester of Comparative Example 9, which does not have the polyfunctional compound unit (III), is inferior in the parison drawdown property, and has an average wall thickness of 0.1 when the bottle is manufactured by extrusion blow molding. 20mm, thickness unevenness 0.50mm
It is inferior in blow moldability, and the resulting bottle is extremely thin at the center of the body, and has a drop breaking height of 50 cm, low drop impact strength, and low quality. I understand.

Further, from the results in Tables 12 and 14, from the results shown in Tables 12 and 14, the diol unit (I) and / or diol unit (II) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus, and the polyfunctional compound unit ( Comparative Example having (III) but having a benzene unit (I) and / or diol unit (II) having a benzene nucleus in a proportion of more than 7 mol% based on the total number of moles of all structural units of the copolymerized polyester. Since the copolymerized polyester of No. 10 was amorphous, the degree of polymerization could not be increased by solid phase polymerization, a high melt viscosity could not be obtained at a temperature of 270 ° C., and extrusion blow molding could not be performed. Extrusion blow molding was performed at a temperature of 210 ° C, which was barely possible, but the parison was inferior in drawdown properties. When the bottle was manufactured according to the shape, the thickness unevenness of the bottle was 0.45 mm, indicating that the blow moldability was poor. In addition, the bottle obtained in Comparative Example 10 was extremely low in surface roughness due to molding at a low temperature, and therefore had a haze value of more than 8 and was inferior in transparency and also had a poor tactile sensation. Further, it can be seen that the drop breaking height is 50 cm, the drop impact strength is small and the quality is low.

From the results shown in Tables 13 and 14, the diol unit (I) mainly composed of a terephthalic acid unit and an ethylene glycol unit and having a benzene nucleus and / or
Alternatively, it has a bis [4- (2-hydroxyethoxy) phenyl] sulfone unit as the diol unit (II) and a trimellitic acid unit as the polyfunctional compound unit (III). The copolymerized polyester of Comparative Example 11 in which the ratio of (2-hydroxyethoxy) phenyl] sulfone units exceeds 7 mol% based on the total number of moles of all the structural units of the copolymerized polyester is bis [4-
In addition to a large proportion of (2-hydroxyethoxy) phenyl] sulfone units, the crystallinity was low and the degree of polymerization could not be increased by solid phase polymerization, and the intrinsic viscosity was increased by melt polymerization at a high temperature. [-(2-Hydroxyethoxy) phenyl] sulfone unit is significantly deteriorated by heat, and when the bottle is manufactured by extrusion blow molding, the haze value and the b value of the bottle each exceed 8, indicating that the transparency is poor. In addition, the melt viscosity behavior of the copolyester of Comparative Example 11 was not appropriately controlled, and the drawdown property of the parison was inferior. When the bottle was manufactured by extrusion blow molding, the thickness unevenness of the bottle was 0.1%. 35m
m, which is inferior in blow moldability. In addition, the bottle obtained in Comparative Example 11 had a remarkably rough surface, and thus had a haze value of more than 8 and a poor touch. In addition, the obtained bottle has a drop breaking height of 90 cm, a small drop impact strength and low quality.

From the results shown in Tables 13 and 14, the diol unit (I) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus and / or
Alternatively, it has a bis [4- (2-hydroxyethoxy) phenyl] sulfone unit as the diol unit (II) and a trimellitic acid unit as the polyfunctional compound unit (III), but only by melt polymerization. 0.8d intrinsic viscosity
1 / g of the copolymerized polyester of Comparative Example 12 did not have a high melt viscosity at a temperature of 270 ° C.
The ratio of poorly formed bottles exceeded 30 out of 100 bottles, the drawdown of parison was inferior, and the average wall thickness of the bottles was 0.2 when the bottles were manufactured by extrusion blow molding.
5 mm, and the thickness unevenness was 0.40 mm, indicating that the blow moldability was poor. Moreover, Comparative Example 1
The haze value and the b value of the bottle obtained in No. 2 each exceeded 4 due to whitening and thermal deterioration of the bis [4- (2-hydroxyethoxy) phenyl] sulfone unit, indicating that the bottle was inferior in transparency. In addition, the drop breaking height is 80cm
This indicates that the drop impact strength is low and the quality is low.

From the results shown in Tables 13 and 14, the diol unit (I) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus and / or
Alternatively, it has a bis [4- (2-hydroxyethoxy) phenyl] sulfone unit as the diol unit (II) and a trimellitic acid unit as the polyfunctional compound unit (III). The copolymerized polyester of Comparative Example 13 in which the ratio of (2-hydroxyethoxy) phenyl] sulfone units exceeds 7 mol% based on the total number of moles of all structural units of the copolymerized polyester is bis [4-
In addition to a large proportion of (2-hydroxyethoxy) phenyl] sulfone units, the crystallinity was low and the degree of polymerization could not be increased by solid phase polymerization, and the intrinsic viscosity was increased by melt polymerization at a high temperature. -(2-Hydroxyethoxy) phenyl] sulfone unit has a remarkable thermal deterioration, and when a bottle is manufactured by extrusion blow molding, the haze value of the bottle exceeds 4, and the b value exceeds 8, and the transparency is poor. Recognize. Moreover, since the intrinsic viscosity of the copolymerized polyester of Comparative Example 13 was less than 1.0 dl / g, sufficient melt viscosity was not obtained, and the drawdown property of the parison was inferior. When the bottle was manufactured, the average wall thickness of the bottle was 0.25 mm, and the thickness unevenness was 0.35 mm, indicating that the blow moldability was poor. In addition, the drop breaking height is 80 cm, the drop impact strength is small, and it can be seen that the quality is low.

From the results shown in Tables 13 and 14, the diol unit (I) mainly composed of terephthalic acid units and ethylene glycol units and having a benzene nucleus and / or
Or 2,2-bis [4-
(2-Hydroxyethoxy) phenyl] propane units and pentaerythritol units as polyfunctional compound units (III), but only the intrinsic viscosity was increased to 0.70 dl / g only by melt polymerization. The copolymer polyester of Comparative Example 14 did not have a high melt viscosity at a temperature of 270 ° C., was inferior in the drawdown property of a parison, and had an average wall thickness of the bottle when the bottle was manufactured by extrusion blow molding. Is 0.25 mm and thickness unevenness is 0.4
5 mm, which indicates that the blow moldability is poor. Moreover, it can be seen that the bottle obtained in Comparative Example 14 has a drop breaking height of 50 cm, a small drop impact strength, and is of low quality.

[0136]

The copolymerized polyester of the present invention has high melt viscosity, low viscosity at high shear rate and high viscosity at low shear rate, and exhibits non-Newtonian properties such as sharkskin flow during molding. Melt fracture does not occur, the crystallization rate is suppressed, and because it has excellent properties that do not produce bumps, it is extremely excellent in melt moldability, extrusion blow molding using the copolymerized polyester of the present invention, When melt molding such as injection / extrusion blow molding, extrusion molding, injection molding, etc., there is no whitening or bumps,
High quality with excellent properties such as transparency, surface condition, appearance, and feel, and also excellent mechanical properties such as impact resistance, mechanical properties, dimensional accuracy, heat resistance, moisture resistance, chemical resistance, etc. Can be manufactured extremely smoothly. And, the copolymerized polyester of the present invention has a high melt viscosity and good melt viscosity characteristics suitable for use in melt molding involving a melt extrusion step, particularly extrusion blow molding among the above melt molding methods, Therefore, when extrusion blow molding is performed using the copolymerized polyester of the present invention, the extruded parison has good drawdown properties, and the drawdown time of the parison is kept in an appropriate range. To produce hollow molded products with a uniform diameter, good blow moldability, no distortion or deformation, good shape and dimensional accuracy, without trouble during molding, with good productivity. It can also be used very suitably for extrusion blow molding of a large hollow molded article accompanied by extrusion of a relatively long parison having a length of 30 cm or more. Further, in the case of the method for producing a copolymerized polyester of the present invention, a copolymerized polyester having the above-mentioned excellent properties can be produced economically with good productivity in a short time, particularly in a reduced solid-state polymerization time. Can be.

Claims (7)

[Claims] (1) a copolymer polyester mainly composed of a dicarboxylic acid unit composed of a terephthalic acid unit and a diol unit composed of an ethylene glycol unit and having another copolymerized unit; (2) the copolymerized polyester described above. As other copolymerized units: (i) (a) the following general formula (I); [In the formula, A represents a formula: —CH ₂ CH ₂ — or a formula: —CH (C
H ₃ ) a group represented by CH ₂ —, B is a divalent hydrocarbon group, a carbonyl group, a sulfonyl group, an oxygen atom or a direct bond (−), R ¹ and R ² are inert substituents, j and k, respectively. Each independently represents an integer of 0 to 8, and s and t each independently represent an integer of 0 to 4]; and (b) a diol unit represented by the following general formula (I)
I); [In the formula, A represents a formula: —CH ₂ CH ₂ — or a formula: —CH (C
H ₃ ) a group represented by CH ₂ —, R ³ is an inert substituent, m and n are each independently an integer of 0 to 8, and u is 0
At least one difunctional compound unit selected from the group consisting of diol units (II) represented by the following formulas: 0 to 4 based on the total number of moles of all structural units of the copolymerized polyester.
(Ii) 3 or more carboxyl groups, hydroxyl groups and / or their ester-forming groups, and at least one of them has a carboxyl group or an ester thereof. The amount of the polyfunctional compound unit (III) derived from at least one of the polyfunctional compounds as the forming group is 0.000 based on the total number of moles of all structural units of the copolymerized polyester.
(3) A copolymerized polyester having an intrinsic viscosity of 1.0 to 1.4 dl / g. 2. A shear rate of 0.1 at a temperature of 270 ° C.
The melt viscosity at rad / sec (η1) is 5 × 10 ^{4 to} 5 × 10
⁶ poise, shear rate 10 at a temperature of 270 ° C.
The melt viscosity at 0 rad / sec (η2) is 5 × 10 ^{3 to} 5 × 1
0 is ⁵ poise, and the melt viscosity (.eta.1) and melt viscosity (.eta.2) is the following formula (α); -0.7 ≦ (1/3 ) log 10 (η2 / η1) ≦ -0.2 ( The copolymerized polyester according to claim 1, which satisfies α). 3. A sharkskin critical shear stress (σss) at a temperature of 270 ° C. is 1 × 10 ⁶ dyne / cm ² or more, and a shear stress (σ100) at a shear rate of 100 / sec at a temperature of 270 ° C. The copolyester according to claim 1 or 2, which has a skin critical shear stress (σss) or less. 4. A molded article comprising the copolymerized polyester according to claim 1. 5. The molded article according to claim 4, which is an extrusion blow molded article. 6. A method for producing a molded product by extrusion blow molding using the copolymerized polyester according to claim 1. 7. A method for producing a copolymerized polyester mainly comprising a dicarboxylic acid unit composed of a terephthalic acid unit and a diol unit composed of an ethylene glycol unit and having another copolymerized unit; [1] Terephthalic acid or an ester thereof It is mainly composed of a dicarboxylic acid component composed of a forming derivative and a diol component composed of ethylene glycol. In addition to the above-mentioned main dicarboxylic acid component and diol component, (a) the following general formula (IV): [In the formula, A represents a formula: —CH ₂ CH ₂ — or a formula: —CH (C
H ₃ ) a group represented by CH ₂ —, B is a divalent hydrocarbon group, a carbonyl group, a sulfonyl group, an oxygen atom or a direct bond (−), R ¹ and R ² are inert substituents, j and k, respectively. Each independently represents an integer of 0 to 8, and s and t each independently represent an integer of 0 to 4]; a diol (IV) shown below; [In the formula, A represents a formula: —CH ₂ CH ₂ — or a formula: —CH (C
H ₃ ) a group represented by CH ₂ —, R ³ is an inert substituent, m and n are each independently an integer of 0 to 8, and u is 0
At least one bifunctional compound selected from the group consisting of a diol (V) represented by the following formula: and an ester-forming derivative thereof; and (b) a carboxyl group, a hydroxyl group and / or an ester thereof. At least one of the polyfunctional compounds having three or more functional groups, at least one of which is a carboxyl group or an ester-forming group thereof.
And (c) the content of the bifunctional compound in the reaction material is higher than the content of the diol unit (I) and / or the diol unit (II) derived from the bifunctional compound. (D) the content of the polyfunctional compound in the reaction raw material is 0.5 to 7 mol% based on the total number of moles of all structural units of the copolymerized polyester; The reaction raw material having an amount such that the ratio of the polyfunctional compound unit (III) derived from the functional compound is 0.005 to 0.5 mol% based on the total number of moles of all the structural units of the copolymerized polyester is obtained by esterification. After the esterification reaction or transesterification reaction, it is melt-polymerized to form a polyester prepolymer; and [2] the polyester prepolymer obtained in the step [1] is subjected to solid-state polymerization; The features of claim 1
4. The method for producing the copolymerized polyester according to any one of items 1 to 3.