JPH07258396A - Copolyester for extrusion blow molding and blowmolded product thereof - Google Patents

Abstract

PURPOSE:To obtain the polyester which is excellent in moldability and can provide blow-molded product excellent in trans-parency by forming it so that it may comprise specified structural units, have a specified ration among them and have specified properties. CONSTITUTION:This polyester is one mainly consisting of structural units (A) of the formula I, structural units (B) of the formula II, structural units (C) of the formula III and structural units (D) of the formula IV, wherein the ratio of the number of moles of structural units B to the total number of moles of structural units B, C and D is in the ragne of 85/100 to 97/100, and the ratio of the number of moles of structural units C to the total number of moles of structural units of C and D is in the range of 70/100 to 90/100, and wherein the glass transition point is 60 deg.C or above, and the intrinsic viscosity is in the range of 0.8-1.5dl/g when measured in a phenol/tetrachloroethane equal-weight mixed solvent at 30 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a copolymerized polyester for extrusion blow molding, which gives a hollow molding having excellent extrusion blow moldability, transparency and heat resistance, and an extrusion blow hollow molding comprising the same. And a method for producing a hollow molded article using the copolymerized polyester for extrusion blow molding.

[0002]

2. Description of the Related Art As a method for manufacturing hollow molded products such as plastic bottles, melt plasticization is used because of the simplicity of the process, high productivity, and low equipment costs for molding machines and molds. The resin is extruded through a die orifice to form a cylindrical parison, and the so-called extrusion blow molding method, which is a molding method in which a fluid such as air is blown inside by sandwiching the parison with a mold while it is in a softened state, is industrially advantageous. Is. In this extrusion blow molding, a vinyl chloride resin or polyolefin having a high melt viscosity is generally used because it is necessary to avoid a remarkable drawdown of the parison extruded in a molten state. However, since vinyl chloride resin may generate toxic gas when incinerated, its use is decreasing mainly in Europe. Further, in the case of polyolefin, white turbidity due to crystallization occurs, so that it is difficult to obtain a hollow molded article having good transparency.

On the other hand, a hollow molded article obtained by melt-molding a polyester resin such as polyethylene terephthalate is excellent in transparency, mechanical properties, gas barrier property and flavor barrier property, and moreover it is a hollow molded product made of vinyl chloride resin. As a substitute for conventional bottles made of vinyl chloride resin, etc., juice, soft drinks, seasonings, oils, cosmetics, detergents, etc. In recent years, it has been widely used as a bottle or other container for accommodating the. However, since polyester resins such as polyethylene terephthalate generally do not have the high melt viscosity required for extrusion blow molding, when attempting extrusion blow molding, the parison after extrusion remarkably draws down and is shaped. Difficult to do. Further, polyester resins such as polyethylene terephthalate generally have a problem that crystallization easily occurs at the time of blowing after extrusion, impairing transparency and causing improper shaping. These disadvantages caused by the low melt viscosity and the high crystallization are particularly remarkable in extrusion blow molding via a long parison having a length of about 20 cm or more, which is necessary for the production of large hollow moldings and the like. Therefore, from polyester resin such as polyethylene terephthalate, the shape and
It is generally difficult to obtain a hollow molded product having uniform dimensions and good transparency, especially a large hollow molded product. Under these circumstances, generally, a method for manufacturing a hollow molded product made of polyester resin is an injection molding method in which molten polyester resin is injected into a mold to form a molded product as it is, or a molten resin is injected into a mold. An injection blow molding method in which a hermetically sealed parison (preform) is once formed and then it is inserted into a blow mold and air is blown in is adopted. However, the injection molding method and the injection blow molding method require high technology in mold making and molding, and it is difficult to manufacture a hollow molded product having a complicated shape having a thin object, a deep object, a large object, a handle, and the like. It has the drawback of being. In addition, these molding methods have a problem that they are not suitable for high-mix low-volume production because of high equipment costs such as molds and molding equipment. In order to improve extrusion blow moldability, a polyester obtained by copolymerizing polyethylene terephthalate with another monomer component has been proposed. For example, JP-A-5-653
No. 38 proposes polyethylene terephthalate obtained by copolymerizing an ethylene oxide adduct of bisphenol A. As a specific example, bisphenol A is proposed.
There is described a production example of a polyethylene terephthalate copolymer obtained by copolymerizing a compound obtained by adding 2 molecules of ethylene oxide to 1 molecule of the above, by a melt polycondensation method.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention According to the description of the above-mentioned Japanese Unexamined Patent Publication No. 5-65338, the inventors of the present invention used the melt polycondensation method to obtain 2 molecules per 1 molecule of bisphenol A.
Polyethylene terephthalate was produced by copolymerizing a compound to which ethylene oxide of the molecule was added.The extrusion blow moldability of the obtained polyester was improved as compared with homopolyethylene terephthalate, but it was still unpractical. It turned out to be a sufficient level. Generally, in melt polycondensation for producing a polyester resin, there is a limit to increase the degree of polymerization due to the decomposition reaction, and only a polyester resin having a low melt viscosity can be obtained. As a means for increasing the melt viscosity of such a low melt viscosity polyester resin, there is known a method in which the prepolymer obtained by melt polycondensation is subjected to solid phase polymerization in the form of chips or the like to increase the polymerization degree. There is. However, when the present inventors applied this method to ordinary polyester resins such as polyethylene terephthalate, the solid-phase polymerization rate was extremely slow, and the target polyester resin having a high degree of polymerization could be obtained in a short time. Since it cannot be obtained efficiently, it was found to be impractical in terms of productivity. Moreover, when the prepolymer is solid-phase polymerized, chips are likely to stick to each other, and in order to prevent sticking, it is necessary to produce a prepolymer having a melting point of 210 ° C. or higher by melt polycondensation. It was a disadvantage. Further, the inventors of the present invention produced a polyethylene terephthalate-based copolyester resin having a lowered melting point and tried extrusion blow molding by setting the melt extrusion temperature to a relatively low temperature, but the melt viscosity at the extrusion temperature was The degree of polymerization is low because the solid state polymerization cannot be performed because the copolyester resin is not so expensive and the melting point of the copolyester resin is low. Therefore, the obtained hollow molded article has low mechanical properties such as impact resistance. However, good results were not obtained.

Therefore, an object of the present invention is to overcome the drawbacks of such polyethylene terephthalate and many polyethylene terephthalate type copolymers, and to provide a hollow molded article excellent in extrusion blow moldability and transparency. An object of the present invention is to provide a polyethylene terephthalate-based copolymerized polyester for extrusion blow molding, a hollow molded article made of the same, and a method for producing the hollow molded article.

[0006]

The inventors of the present invention continued their studies and found that an esterification reaction or transesterification reaction was carried out using a raw material containing a terephthalic acid component, ethylene glycol and a specific bisphenol A ethylene oxide adduct. After that, it is melt-polycondensed to form a polyester prepolymer, and when the prepolymer is solid-phase polymerized, a polyester resin having a high melt viscosity can be produced with good productivity in a short time. The polyester resin thus obtained has a high shear rate and a low viscosity,
The present invention has been completed by finding that it exhibits non-Newtonian melt viscosity characteristics such as high viscosity at a low shear rate and is suitable for extrusion blow molding.

That is, the present invention is, firstly, mainly of the formula (I)

[0008]

[Chemical 5]

The structural unit (1) represented by the formula (II)

[0010]

[Chemical 6]

The structural unit (2) represented by the formula (III)

[0012]

[Chemical 7]

The structural unit (3) represented by and the formula (IV)

[0014]

[Chemical 8]

The constitutional unit (4) is represented by the following formula, and the constitutional unit (2) and the constitutional unit (3) have the same number of moles as the constitutional unit (2).
And the ratio of the number of moles of structural unit (4) to 85 /
Within the range of 100 to 97/100, the structural unit (3)
The ratio of the number of moles of the structural unit (3) to the sum of the number of moles of the structural unit (4) is in the range of 70/100 to 90/100, the glass transition temperature is 60 ° C. or higher, and phenol and tetra Intrinsic viscosity at 30 ° C. in an equal weight mixed solvent of chloroethane is 0.8 dl / g to 1.5 dl
It is a copolyester for extrusion blow molding, characterized in that it is in the range of / g.

A second aspect of the present invention is an extrusion blow hollow molded article comprising the above-mentioned copolymerized polyester for extrusion blow molding.

Thirdly, the present invention thirdly comprises: when extrusion-blow-molding the above-mentioned copolyester for extrusion blow-molding,
It is a method for producing a hollow molded article, in which extrusion is carried out at a temperature in the range of 10 ° C. or higher above the melting point of the copolyester and 60 ° C. or higher above the melting point.

In the extrusion blow molding copolymerized polyester of the present invention, the ratio of the number of moles of the structural unit (2) to the sum of the number of moles of the structural unit (2), the structural unit (3) and the structural unit (4) is set. It is necessary to be within the range of 85/100 to 97/100. The molar ratio is 85/1
When it is less than 00, the stretch orientation is inferior and the mechanical strength of the hollow molded article obtained by extrusion blow molding becomes insufficient. In addition, the coloring which is considered to be caused by the thermal decomposition of the structural unit (3) and the structural unit (4) is remarkable, and the color tone of the obtained hollow molded article is deteriorated. Furthermore, the melting point of the prepolymer obtained by melt polycondensation is too low, or the prepolymer becomes amorphous. For this reason, solid-state polymerization becomes impossible, or the solid-state polymerization temperature must be lowered in order to prevent sticking of the prepolymer chips, resulting in a low polymerization rate and markedly poor productivity. On the other hand, when the ratio of the number of moles of the structural unit (2) to the total number of moles of the structural unit (2), structural unit (3) and structural unit (4) is greater than 97/100, the melt viscosity is low. The drawdown of the parison is severe during extrusion blow molding, resulting in poor moldability. Even if extrusion blow molding is possible for some time, spherulites are likely to be generated during molding, so that the obtained hollow molded article is liable to be whitened or defective in molding. Melt viscosity is sufficiently high, extrusion blow moldability is good, coloration, whitening and improper molding of hollow molded products are prevented, sufficient mechanical strength is obtained, and solid-phase polymerization is also possible in terms of resin production. In this case, since there is no sticking between the prepolymer chips and the productivity is good, the number of moles of the structural unit (2), the structural unit (2), the structural unit (3) and the structural unit (4) It is particularly preferred that the ratio of the number of moles to the sum is within the range of 90/100 to 95/100.

In the extrusion blow molding copolymerized polyester of the present invention, the ratio of the number of moles of the structural unit (3) to the sum of the number of moles of the structural unit (3) and the structural unit (4) is 70/100 to 90 /. It should be in the range of 100. When the ratio of the number of moles is less than 70/100, coloring which is considered to be caused by thermal decomposition of the structural unit (4) is remarkable and the appearance of the hollow molded article obtained is impaired. In addition, the heat resistance of the obtained hollow molded article becomes insufficient due to the decrease of the glass transition temperature. On the other hand, when the ratio of the number of moles of the structural unit (3) to the sum of the number of moles of the structural unit (3) and the structural unit (4) is greater than 90/100, the shear rate dependence of the melt viscosity is small and the extrusion rate is small. Blow moldability becomes poor. That is, since the melt viscosity is high when passing through the die orifice, which is a condition of high shear rate, the drawdown of the parison becomes intense due to heat generation, the extrusion amount is difficult to control and the extrusion unevenness occurs, and the weld line occurs. . In addition, since the melt viscosity is low in the process of forming the parison after passing through the die orifice, which is a condition of low shear rate, drawdown of the parison is severe, resulting in poor molding.
Further, in solid phase polymerization, the polymerization rate is reduced, which causes a problem in productivity. The extrusion blow moldability is good, and the resulting hollow molded article has a good appearance such as transparency (including color tone), so that the number of moles of the structural unit (3) and the structural unit (3) It is particularly preferable that the ratio of 4) to the sum of the number of moles is in the range of 80/100 to 87/100.

The glass transition temperature of the copolyester for extrusion blow molding of the present invention is 60 ° C. or higher. When the glass transition temperature is lower than 60 ° C., after the extrusion blow hollow molded article is taken out of the mold, shrinkage occurs due to relaxation of residual stress, and the appearance of the molded article is deteriorated, which is not preferable. In order to prevent shrinkage of the hollow molded product more strictly,
It is particularly preferable that the glass transition temperature is 70 ° C. or higher. In the extrusion blow molding copolymerized polyester of the present invention, the intrinsic viscosity at 30 ° C. in a mixed solvent of equal weight of phenol and tetrachloroethane is 0.8 dl / g to
It is within the range of 1.5 dl / g. Intrinsic viscosity is 0.8 dl
If it is less than / g, the drawdown of the parison during extrusion blow molding becomes severe, resulting in poor molding, and mechanical properties such as strength and impact resistance of the resulting hollow molded product become insufficient. On the other hand, if the intrinsic viscosity is greater than 1.5 dl / g,
Since the melt viscosity is too high, a weld line is formed at the time of extrusion blow molding, and the appearance of the obtained hollow molded product is significantly impaired. In addition, since the torque increases during resin extrusion, molding problems such as non-uniform extrusion may occur, and the productivity of molded products may decrease. In order to make the extrusion blow moldability and the mechanical performance, appearance and productivity of the resulting hollow molded product particularly good, the intrinsic viscosity is 0.9.
It is particularly preferable that it is in the range of dl / g to 1.2 dl / g.

In the extrusion blow molding copolymerized polyester of the present invention, the melt viscosity at a temperature 40 ° C. higher than the melting point is 8 × 1 at a shear rate of 0.1 rad / sec.
Within the range of 0 ⁴ poise to ⁵ × 10 ⁵ poise,
8 × 10 ³ po at a shear rate of 100 rad / sec
The shear rate is 0.1 rad / at a temperature within the range of from 5 × 10 ⁴ poise and 40 ° C. higher than the melting point.
sec and a shear viscosity of 100 rad / sec, the melt viscosity (poise) measured under each condition was measured.
When plotted on both natural logarithmic scales with the shear rate as the horizontal axis, the slope of the straight line connecting the two points is -0.2 to -0.
5 [that is, the melt viscosity at a shear rate of 0.1 rad / sec under the above temperature conditions is η
_{When 1} (poise) and the melt viscosity at a shear rate of 100 rad / sec are η ₂ (poise), (1/3)
The value of log ₁₀ (η ₂ / η ₁ ) is preferably in the range of −0.2 to −0.5]. When the melt viscosity at a temperature 40 ° C. higher than the melting point is 8 × 10 ⁴ poise or more at a shear rate of 0.1 rad / sec, the drawdown property of the parison becomes extremely good. On the other hand, the melt viscosity at a temperature 40 ° C. higher than the melting point has a shear rate of 0.1 rad / se.
When c is 5 × 10 ⁵ poise or less, curl back is particularly unlikely to occur at the time of melt extrusion, and molding defects hardly occur. Also, melt fracture in melt extrusion and die swel
The phenomenon of l) is remarkably suppressed, and the appearance and uniformity of the obtained hollow molded product are particularly good. When the melt viscosity at a temperature 40 ° C. higher than the melting point is 8 × 10 ³ poise or more at a shear rate of 100 rad / sec, the melt viscosity immediately after melt extrusion from the die orifice is sufficiently high, and the drawdown property of the parison becomes extremely good. . On the other hand, the melt viscosity at a temperature 40 ° C. higher than the melting point has a shear rate of 100 ra.
When d / sec is 5 × 10 ⁴ poise or less,
Since the melt viscosity at the time of extrusion is not too high, the heat generation that promotes drawdown of the parison is reduced, the extrusion amount is easily adjusted, extrusion unevenness is significantly suppressed, and the occurrence of weld lines is also significantly suppressed. Melt viscosity (poise) measured under conditions of a shear rate of 0.1 rad / sec and a shear rate of 100 rad / sec at a temperature 40 ° C. higher than the melting point is a natural logarithmic scale with the melt viscosity as the vertical axis and the shear rate as the horizontal axis. 2 when plotted with
When the slope of the straight line connecting the points is within the range of -0.2 to -0.5, it exhibits an appropriate non-Newtonian property, exhibits a moderately low melt viscosity at a high shear rate, and has an appropriate degree at a low shear rate. Since it has a high melt viscosity, the parison moldability in resin extrusion becomes particularly good. If the slope is −0.
When it is in the range of 25 to -0.45, the melt viscosity characteristic becomes particularly preferable, and the parison moldability in resin extrusion becomes more favorable. In addition, the melt viscosity in the present invention is dynamically measured using a dynamic viscoelasticity measuring device for a melted sample existing between parallel plates.

The copolyester for extrusion blow molding of the present invention has a temperature of 0.5 to 7.
It preferably has a melt flow rate in the range of 5 g / 10 min. When the melt flow rate under the temperature condition is 0.5 g / 10 min or more, the torque during resin extrusion is not too high, so that the obtained hollow molded article is prevented from becoming non-uniform and the productivity from decreasing. On the other hand, when the melt flow rate at a temperature 40 ° C. higher than the melting point is 7.5 g / 10 min or less, excessive drawdown of the parison during extrusion is suppressed and moldability is improved. From the viewpoints of moldability in extrusion blow molding, uniformity of hollow molded articles, and productivity, the melt flow rate at a temperature 40 ° C. higher than the melting point is more preferably in the range of 1 to 5 g / 10 min. In the present invention, the melt flow rate at a temperature 40 ° C. higher than the melting point means that a polymer sample such as polyester has an inner diameter of 9.5.
When filled in a cylinder having a length of 5 mm and a length of 162 mm, the polymer in the cylinder is melted at a temperature 40 ° C. higher than the melting point, and a load of 2160 g and a diameter of 9.48 mm is placed on the upper part of the cylinder and the load is evenly applied. In addition, the velocity (polymer amount) of the molten polymer extruded from an orifice having a diameter of 2.1 mm and a length of 8 mm provided in the center of the cylinder (polymer amount: g / 10 m
in) is the value when measured.

As the method for producing the copolyester of the present invention, a method according to a known polyester production method can be adopted. That is, the copolyester of the present invention can be prepared by either a direct method of polycondensation reaction of dicarboxylic acid and diol or a transesterification method of polycondensation reaction of dicarboxylic acid lower alkyl ester compound and diol by transesterification reaction. It is produced by producing a polymer followed by solid state polymerization.

The copolymerized polyester of the present invention comprises terephthalic acid or an ester-forming derivative thereof (lower alkyl ester such as dimethyl ester and diethyl ester of terephthalic acid), ethylene glycol, bisphenol A.
To one molecule of (2,2-bis [4- (2-hydroxyethoxy) phenyl] propane; hereinafter referred to as EOBPA2) and one molecule of bisphenol A A compound in the form of addition of 3 molecules of ethylene oxide (2- [4-
(2-Hydroxyethoxy) phenyl] -2- [4-
It is produced by using [2- (2-hydroxyethoxy) ethoxy] phenyl] propane; hereinafter referred to as EOBPA3) as an essential raw material monomer. In the solid phase polymerization, the polyester (prepolymer) obtained by melt polycondensation is heated under a reduced pressure or under an inert gas flow to a temperature usually in the range of 180 ° C. to 230 ° C. and below the melting point to obtain the object. The degree of polymerization may be reached. In the production of the copolyester for extrusion blow molding of the present invention, from the viewpoint of preventing sticking between chips, it is preferable to adopt a temperature lower than the melting point by 15 ° C. or more as the solid phase polymerization temperature, and a temperature lower than 20 ° C. Is more preferably adopted. In the solid-state polymerization for obtaining the copolymerized polyester of the present invention, the polymerization rate is remarkably high and the melt viscosity is high as compared with homopolyethylene terephthalate and many other polyethylene terephthalate-based polyester copolymers. A polyester resin having properties suitable for extrusion blow molding in terms of shear rate dependence (non-Newtonian property) is produced in a very short time with high productivity. From the viewpoint that a polyester resin having properties suitable for such extrusion blow molding can be easily obtained, solid phase polymerization is preferably carried out at a temperature of 220 ° C. or lower for 10 hours or longer, and 210 ° C. or lower for 20 hours or longer. More preferable.

The copolymerized polyester of the present invention is prepared from terephthalic acid, ethylene glycol, EOBPA2 and EOB.
An example of a method for producing using PA3 as a raw material monomer is shown below. Dicarboxylic acid consisting mainly of terephthalic acid, and mainly ethylene glycol, EOBPA2
And a diol consisting of EOBPA3, wherein the total amount of the diol is an excess molar amount with respect to the total amount of the dicarboxylic acid,
For example, while distilling the produced water at a ratio of 1.1 to 1.5 times the molar ratio, under normal pressure or under a pressure of about 3 Kg / cm ² or less in absolute pressure, at a temperature of about 230 to 280 ° C. After esterification, and if necessary, additives such as polycondensation catalyst and anti-coloring agent are added, and then the produced polyester has a desired intrinsic viscosity at about 200 to 280 ° C. under reduced pressure of 5 mmHg or less. The prepolymer is obtained by melt polycondensation up to. Melt polycondensation is 255
More preferably, it is carried out at a temperature of ˜270 ° C. In melt polycondensation, usually, the intrinsic viscosity of the prepolymer measured at 30 ° C. in a mixed solvent of equal weight of phenol and tetrachloroethane is made to reach the range of 0.40 to 0.75 dl / g. The melt polycondensation is the melt flow rate of the resulting polyester (from the melting point measured by the above method,
Melt flow rate at high temperature of 0 ° C) is 15.0
It is preferable to finish the process within the range of g / 10 min or more because the time required for the melt polycondensation reaction can be shortened. As the polycondensation catalyst, those known in the production of polyesters can be used. Typical examples are antimony compounds such as antimony oxide; germanium compounds such as germanium oxide; tetramethoxy titanium, tetraethoxy titanium, tetra n-propoxy titanium, Examples thereof include titanium compounds such as tetraisopropoxytitanium and tetrabutoxytitanium; tin compounds such as di-n-butyltin dilaurate, di-n-butyltin oxide, and dibutyltin diacetate. These compounds can be used in combination. The polycondensation catalyst is preferably used in an amount such that it falls within the range of 0.002 to 0.8% by weight based on the copolyester produced. In addition, the above-mentioned esterification reaction, transesterification reaction and / or melt polycondensation reaction is carried out by using a diethylene glycol by-product inhibitor selected from tetraalkylammonium hydroxide such as tetraethylammonium hydroxide; amines such as triethanolamine and triethylamine. You may go in the presence. Examples of the color preventive agent include phosphorus compounds such as phosphorous acid, phosphoric acid, trimethyl phosphite, triphenyl phosphite, tridecyl phosphite, trimethyl phosphate, tridecyl phosphate, and triphenyl phosphate. It is generally used in an amount of 0.001 to 0.5% by weight based on the polymerized polyester. Further, in order to suppress the coloring due to the thermal decomposition of the ethylene oxide adduct of bisphenol A, a manganese compound such as manganese acetate is added in an amount of 0.001 to 0.001 with respect to the produced copolyester.
It is preferably added in an amount such that it is within the range of 0.5% by weight, and particularly within the range of 0.05 to 0.3% by weight.

Next, the obtained prepolymer is solidified to an appropriate size, and then solid-phase polymerized at 180 ° C to 230 ° C. In this solid phase polymerization, the prepolymer is made into chips or other particles of any shape such as a die shape or a column shape, which are usually pre-dried at 190 ° C or lower, and then under vacuum, under reduced pressure or under nitrogen or the like. It is carried out by heating in an active gas until the intrinsic viscosity of the copolyester or other physical properties such as the melt flow rate reach a desired value. The solid phase polymerization is preferably carried out while fluidizing the particles by a suitable method such as a rolling method or a gas fluidized bed method so that the particles of the prepolymer do not stick to each other. In the production of the copolyester of the present invention, the prepolymer is generally solid phase polymerized at a temperature of 190 to 230 ° C. for about 10 to 40 hours, although it may vary depending on the monomer composition, the melt flow rate of the prepolymer, the polymerization temperature and the like. Then, a polyester resin having a melt flow rate of 0.1 to 5.0 g / 10 min can be obtained. On the other hand, in the case of producing polyethylene terephthalate which does not contain the structural unit (3) and the structural unit (4), the melt flow rate is 0.1 to 5.
In order to obtain a high melt viscosity of 0 g / 10 min, normally,
It is necessary to carry out the solid phase polymerization for about 40 to 200 hours. Therefore, in the copolyester of the present invention containing the structural unit (3) and the structural unit (4), the solid phase polymerization time can be significantly shortened as compared with ordinary polyethylene terephthalate, and therefore the copolyester of the present invention. It is understood that is a polyester that is extremely excellent in terms of productivity desired in producing a polyester for extrusion blow molding.

The copolyester of the present invention comprises terephthalic acid or an ester-forming derivative thereof, as described above.
Ethylene glycol, EOBPA2 and EOBPA3
Can be used as a starting material, but other monomers may be used in combination depending on the purpose. Monomers that can be used in combination include isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, sodium-
Aromatic dicarboxylic acids such as sulfoisophthalic acid; Aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid; Alicyclic dicarboxylic acids such as decalin dicarboxylic acid and cyclohexanedicarboxylic acid; glycolic acid, hydroxy Acrylic acid, hydroxypropionic acid, asiatic acid, quinobaic acid, hydroxybenzoic acid, mandelic acid, hydroxycarboxylic acids such as matrolactic acid; aliphatic lactones such as ε-caprolactone; trimethylene glycol, tetramethylene glycol, hexamethylene glycol, Aliphatic diols such as neopentyl glycol, diethylene glycol, polyethylene glycol; hydroquinone, catechol, naphthalene diol, resorcin, bisphenol A, bispheno Forms of the compounds obtained by adding 4 or more molecules of ethylene oxide per molecule of A, bisphenol S, such as ethylene oxide adducts aromatic diol of bisphenol S; cyclohexanedimethanol alicyclic diols such as are exemplified. The amount of these monomers that can be used in combination is preferably such a ratio that the total amount of the constituent units derived therefrom is 10 mol% or less of all the constituent units. If necessary, a small amount of a polyvalent carboxylic acid such as trimellitic acid, trimesic acid, pyromellitic acid or tricarballylic acid; or a polyhydric alcohol such as trimethylolpropane or pentaerythritol can be used as a comonomer.

Since the extrusion blow molding copolymerized polyester of the present invention is excellent in extrusion blow molding as described above,
Even when using a general-purpose extrusion blow molding device such as used for vinyl chloride resin, the extrusion blow molding method can be used to form a hollow molded product of a desired shape and size with high productivity and high uniformity. You can The extrusion blow molding method applied to the copolymerized polyester for extrusion blow molding of the present invention is not particularly limited, and a resin is melt extruded to form a cylindrical parison, and while this parison is in a softened state. In addition, a method of expanding the parison into a predetermined shape by inserting it into a blow mold and blowing a fluid such as air can be adopted. In such melt extrusion, it is preferable to extrude at a temperature in the range of 10 ° C. or more higher than the melting point of the copolyester and 60 ° C. or less higher than the melting point because the moldability becomes particularly good. Incidentally, the extrusion blow molding copolymerized polyester of the present invention, if necessary, may be supplementarily blended with other thermoplastic resin within a range that does not impair the effects of the present invention, and generally, Substances added to thermoplastic resins (for example, stabilizers such as UV absorbers, antistatic agents, flame retardants, flame retardant auxiliaries, colorants such as dyes and pigments, lubricants, plasticizers, inorganic fillers, etc.) May be blended.

The extrusion blow-molded hollow container of the present invention is a copolymerized polyester for extrusion blow-molding (hereinafter, PEMT).
Not only a single-layer bottle made of polyethylene terephthalate (hereinafter referred to as PET) but also a multi-layer bottle made of PET layer-PEMT layer-PET layer, PET layer-PEMT layer-PET layer-P.
It also includes a five-layer bottle consisting of EMT layer-PET layer.

The copolymerized polyester of the present invention overcomes the drawbacks of the conventional polyethylene terephthalate and polyethylene terephthalate type copolymers, has extremely excellent extrusion blow moldability, and is an extrusion blow molded hollow product made of the copolymerized polyester of the present invention. Since the molded product is excellent in transparency (including color tone) and heat resistance, it is useful as various containers such as bottles.

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The measurement conditions of the main characteristic values are as follows.

(1) Content of Constituent Units in Polyester Molecule Each constituent unit in the polyester molecule derived from terephthalic acid, ethylene glycol and a comonomer other than them is based on the total dicarboxylic acid unit or the total diol unit. Was determined by subjecting the methanolysis degradation product of the polyester sample to a separation operation by high performance liquid chromatography and quantitatively analyzing each separated component by IR. In addition, ¹ H-N of the polyester sample using deuterated trifluoroacetic acid as a solvent
The structure was confirmed based on the MR measurement result.

(2) Intrinsic viscosity of polyester In an equal weight mixed solvent of phenol and tetrachloroethane,
It was measured at 30 ° C.

(3) Melt flow rate (MFR) of polyester Measured using a melt indexer L244 manufactured by Takara Kogyo Co., Ltd. Specifically, a polyester chip with an inner diameter of 9.5
It is filled in a cylinder having a length of 5 mm and a length of 162 mm, and the polyester in the cylinder is 40
Melted at a high temperature of 2 ° C and weighed 2160 g and had a diameter of 9.
1. Mount a 48 mm plunger and load the polyester melt evenly, with a diameter in the center of the cylinder 2.
Outflow rate (polyester amount) of polyester melt extruded from an orifice having a length of 1 mm and a length of 8 mm (g / 1
0 min) was measured and this was taken as the melt flow rate.

(4) Melt viscosity (η *) of polyester As a measuring device, a mechanical spectrometer RMS-800 manufactured by Rheometrics was used. Using parallel plate, shear rate 0.1 rad / sec and 100r at a temperature 40 ° C. higher than the melting point of polyester.
The melt viscosity at ad / sec was measured dynamically.

(5) Glass transition temperature of polyester (T
g) and melting point (Tm) Differential scanning calorimetry (DS) based on JIS K7121
According to C), the heating rate was 10 ° C./min.

Example 1 A slurry consisting of 100.00 parts by weight of terephthalic acid, 44.83 parts by weight of ethylene glycol, 7.62 parts by weight of EOBPA2 and 2.17 parts by weight of EOBPA3 was formed, and a polyester was added thereto. Amount of germanium dioxide, 100p
Phosphorous acid in an amount of pm, manganese acetate in an amount of 104 ppm and tetraethylammonium hydroxide in an amount of 100 ppm were added. By heating this slurry under pressure (2.5 Kg / cm ^{2 in} absolute pressure) to a temperature of 250 ° C., an esterification reaction was carried out until the esterification rate reached 95% to produce a low polymer. continue,
An intrinsic viscosity of 0.69 dl / g was obtained by melt polycondensation of a low polymer at a temperature of 270 ° C. under a reduced pressure of 1 Torr absolute pressure.
The polyester prepolymer of 1 was produced, and this was extruded from a nozzle in a strand shape and cut into a cylindrical chip (diameter 2.5 mm, length 3.5 mm). The melt flow rate at a temperature 40 ° C. higher than the melting point of this prepolymer was 35 g / 10 min. Then
The prepolymer chips thus obtained were pre-dried at 150 ° C. for 5 hours, and then dried under reduced pressure of 0.1 mmHg to about 25 ° C. below the melting point.
A high molecular weight polyester was obtained by solid phase polymerization at a low temperature (210 ° C.). The obtained polyester was subjected to methanolysis decomposition, the decomposed product was subjected to a separation operation by high performance liquid chromatography, and each separated component was quantitatively analyzed by IR. The obtained polyester was also subjected to ¹ H-NMR measurement using deuterated trifluoroacetic acid as a solvent. From these measurement results, the obtained polyester was substantially a copolyester composed of the structural unit (1), the structural unit (2), the structural unit (3), the structural unit (4) and the diethylene glycol unit. There was found. Table 1 shows the content of each structural unit. The intrinsic viscosity of the obtained copolyester was 1.10 dl / g, the melt flow rate at a temperature 40 ° C. higher than the melting point was 1.9 g / 10 min, and the melt viscosity at the same temperature was a shear rate of 0.1 rad.
2.2 × 10 ⁵ poise at 100 / sec, shear rate 100
It was 2.5 × 10 ⁴ poise at rad / sec.
When these two pieces of melt viscosity data were plotted on a natural logarithmic scale with the melt viscosity as the vertical axis and the shear rate as the horizontal axis, the slope of the straight line connecting the two points was -0.31. Furthermore, for the copolyester, the Tg and T
m was measured. The results of these evaluations are shown in Table 2.

The obtained copolymerized polyester is extruded by a blow molding machine (manufactured by Suzuki Iron Works Co., Ltd., a blow molding machine TB-S).
T-6P type) and extruded from an annular orifice at an extrusion temperature of 40 ° C. higher than the melting point to form a cylindrical parison, which is cut in a softened state by sandwiching it with a blow molding die. And the bottom part are formed and this is blow-molded, capacity 1000ml, average wall thickness 0.4mm
Manufactured a bottle for a soft drink. The drawdown property and blow moldability of the parison in this extrusion blow molding, and the transparency of the obtained bottle were judged by the following evaluation criteria. The results of these evaluations are shown in Table 2.

(Evaluation of drawdown property of parison) -Drawdown time of parison (sec) In the extrusion blow molding machine used above, the parison has a parison of 25.
cm When the drawdown is done, scissor blow is performed with the mold. Therefore, the time to draw down by 25 cm is important, and the draw down time is usually 15 to 25 s.
In the case of ec, good results are obtained. If it is less than 15 sec, the drawdown becomes severe, the parison shape becomes non-uniform, and a defective product with large thickness unevenness is generated after blowing, or the parison hollow part cannot be inserted into the blow mold and blockage occurs. On the other hand, if it exceeds 25 seconds, the productivity becomes low and the viscosity is too high, so that uniform blowing cannot be performed. It also causes weld lines and damages to the machine due to the increase in torque.

The difference between the maximum width and the minimum width of the parison The diameter of the annular die of the extrusion nozzle is 3.5 cm, but the extruded parison is a drawdown due to its own weight, and the diameter tends to become smaller with distance from the die. . If the difference between the maximum diameter and the minimum diameter of the parison is less than 1 cm, blow molding can be normally performed without any problem. In contrast, the difference is 1 cm
In the above case, unevenness in thickness is caused after blowing, and a defective product is obtained. In a more remarkable case, the parison is blocked and it becomes impossible to blow.

Comprehensive evaluation of drawdown property of parison ○: Cylindrical shape in which the shape of the extruded parison is substantially uniform. Δ: The drawdown is fast and the following defects sometimes occur, or the drawdown is slow and the productivity is poor. X: The drawdown of the extruded parison was so severe that the parison could not be inserted into the blow mold, or the hollow part of the parison was clogged.

(Evaluation of Blow Moldability) -Unevenness of Bottle Thickness The difference between the maximum thickness and the minimum thickness of the obtained bottle body was measured. Since the average wall thickness is set to 0.4 mm, if the thickness unevenness is 0.15 mm or more, the appearance and the touch will be poor and the impact resistance will be poor. ◯: Molded into a bottle having a thickness unevenness of less than 0.15 mm. X: Thickness unevenness is 0.15 mm or more and thickness is 0.1 m
An abnormally thin part of m or less occurs or a damaged part occurs.

(Evaluation of Transparency) Haze Value A portion of the bottle body having a thickness of about 0.4 mm was cut out and measured (ASTM D1003). When the haze value is 5 or more, the transparency is poor due to whitening.

B value The body of the bottle was cut into 1 cm ² , and the color difference meter SM-4 (manufactured by Suga Test Instruments Co., Ltd.) was used to measure by the reflection method.
When the b value is 8 or more, the bottle color tone becomes more yellowish,
Appearance deteriorates. The b value is preferably 4 or less in terms of color tone.

-Comprehensive evaluation of transparency of bottle ◯: Good transparency. Δ: Light yellowish or partial white turbidity due to spherulite formation. X: A dark orange color is formed, or a dark cloudy portion is generated due to the formation of spherulites.

Examples 2-6, Comparative Examples 1-6 Terephthalic acid, ethylene glycol, EOBPA2, E
Esterification, melt polycondensation and solid phase polymerization were carried out in the same manner as in Example 1 except that the amounts of OBPA3 and 1,4-cyclohexanedimethanol used and the solid phase polymerization temperature were changed to the values shown in Table 1 or Table 3. Then, a copolyester having a composition shown in Table 1 or Table 3 was obtained. The characteristics of the obtained polyester were evaluated. The evaluation results are shown in Table 2 or Table 4.
Shown in. However, in Comparative Example 2, solid phase polymerization could not be performed because the obtained polyester was amorphous. Therefore, the melt viscosity of the prepolymer obtained by melt polycondensation was measured at 270 ° C. Further, in Comparative Examples 2 and 6, the drawdown during extrusion blow molding was severe and the bottle could not be manufactured.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

In Tables 1 and 3 above, the monomers used and the structural units corresponding thereto are abbreviated. That is, TPA represents terephthalic acid or the structural unit (1), EG represents ethylene glycol or the structural unit (2), and EOBPA is a structural unit derived from an ethylene oxide adduct of bisphenol A [the structural unit (3) and Structural unit (4)], and EOBPA2
Represents 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane or the structural unit (3), and EOBP
A3 represents 2- [4- (2-hydroxyethoxy) phenyl] -2- [4- [2- (2-hydroxyethoxy) ethoxy] phenyl] propane or the structural unit (4), and CHDM is 1,4- Represents a unit of cyclohexanedimethanol or 1,4-cyclohexanedimethanol,
DEG represents a diethylene glycol unit.

[0052]

The copolymerized polyester for extrusion blow molding of the present invention has high melt viscosity and melt viscosity characteristics suitable for extrusion blow molding, as is apparent from the above-mentioned examples. Thus, it is possible to smoothly and economically form a hollow molded article with high productivity and efficiency. The copolyester for extrusion blow molding of the present invention can also be suitably used for the production of large hollow moldings via a relatively long parison having a length of about 20 cm or more.
Further, the extrusion blow hollow molded article of the present invention has good morphology and transparency due to the copolymerized polyester.

Claims (4)

[Claims] 1. Mainly represented by the formula (I): The structural unit (1) represented by the formula (II): A structural unit (2) represented by formula (III): The structural unit (3) represented by and the formula (IV): The ratio of the number of moles of the structural unit (2) to the sum of the number of moles of the structural unit (2), the structural unit (3) and the structural unit (4) is 85/100 to 97.
/ 100, the ratio of the number of moles of the structural unit (3) to the sum of the number of moles of the structural unit (3) and the structural unit (4) is within the range of 70/100 to 90/100, and the glass Extrusion having a transition temperature of 60 ° C. or higher and an intrinsic viscosity at 30 ° C. in an equal weight mixed solvent of phenol and tetrachloroethane within a range of 0.8 dl / g to 1.5 dl / g. Copolymerized polyester for blow molding. 2. The melt viscosity at a temperature 40 ° C. higher than the melting point is 8 × 10 at a shear rate of 0.1 rad / sec.
It is in the range of ⁴ poise to ⁵ × 10 ⁵ poise and 8 × 10 ³ poi at a shear rate of 100 rad / sec.
The shear rate is 0.1 rad / s at a temperature within the range of se to 5 × 10 ⁴ poise and 40 ° C. higher than the melting point.
ec and the melt viscosity (poise) measured under each condition of a shear rate of 100 rad / sec, the slope of the straight line connecting the two points when plotted on both natural logarithmic scales with the melt viscosity as the vertical axis and the shear rate as the horizontal axis -0.2 to -0.5
The copolymerized polyester for extrusion blow molding according to claim 1, which is within the range. 3. An extrusion blow blow molded product comprising the copolymerized polyester for extrusion blow molding according to claim 1 or 2. 4. When extrusion-blow molding the copolyester for extrusion blow molding according to claim 1 or 2, extrusion is performed at a temperature 10 ° C. or higher above the melting point of the copolyester, and 60 ° C. above the melting point. A method for producing a hollow molded article at a temperature within the following range.