JPH05155992A - Copolyester, and hollow container and oriented film thereof - Google Patents

Abstract

PURPOSE:To obtain a copolyester which is less likely to suffer from metal mold contamination during molding and has excellent heat resistance by imparting specific properties to the copolyester having its dicarboxylic acid component comprising terephthalic acid and its diol component comprising mainly of ethylene glycol. CONSTITUTION:The objective copolyester having its dicarboxylic acid component comprising mainly of terephthalic acid and its diol component comprising mainly of ethylene glycol contains isophthalic acid as another dicarboxylic acid component in an amount of 0.5-3.0mol% and diethylene glycol as another diol component in an amount of 1.0-2.5mol%, has an intrinsic viscosity of 0.50-1.50dl/g, and contains Ge atoms and a cyclic trimer in amounts of 30-60ppm by weight and 0.35wt.% or less, respectively.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a copolyester useful for bottles, films, sheets and the like. More specifically, the present invention relates to a copolymerized polyester which has a low content of oligomers which is unlikely to cause contamination of a mold or the like during molding and is excellent in productivity, heat resistance and mechanical strength, and a molded product thereof.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter referred to as
It is called "PET". ) Has excellent mechanical strength, chemical stability, transparency, hygiene, etc., and since it is lightweight and inexpensive, it is widely used as packaging materials for various sheets and containers, especially carbonated drinks and fruit juices. Significant growth in containers for beverages, liquid seasonings, edible oils, liquors and wines.

In the case of PET, for example, in the case of a bottle, a preform for a hollow molded body is molded by an injection molding machine, and the preform is stretch-blown in a mold having a predetermined shape. Further, in the case of a content liquid such as a fruit juice drink that requires hot filling, it is generally molded in a bottle by further heat fixing in a blow mold or a separately provided mold. Is.

However, in the conventional PET chips used for molding, the amount of the cyclic trimer containing an oligomer as a main component is usually 1 to 2% by weight in the melt-polymerized chips and usually 0.5 in the solid-phase polymerized chips. ~ 1.0 wt%, these oligomers adhere to equipment such as molds during molding,
To contaminate. Contamination of the mold or the like causes the surface of the molded product to become rough or white. Therefore, it is necessary to clean the mold and the like as often as possible.

Therefore, conventionally, attempts have been made to extend the solid phase polymerization time or increase the amount of catalyst to reduce oligomers, but there is a limit to the reduction of oligomers by such a method, and it is economical. Not the right way.

On the other hand, a copolyester having properties similar to PET, for example, a copolyester using terephthalic acid and isophthalic acid as a dicarboxylic acid component and a copolyester using ethylene glycol and diethylene glycol as a glycol component. Is also well known. However, a copolymerized polyester in which the amount of oligomer is reduced to a certain extent or more and which has physical properties equal to or higher than that of PET has not been specifically known.

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is to prevent contamination of molds and the like at the time of molding, to have a low oligomer content, and to reduce oligomer by-products such as molding, and to be equal to or higher than that of conventional PET. Another object of the present invention is to provide a highly productive copolyester having high heat resistance.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, copolymerization in a specific physical property range in which a small amount of isophthalic acid unit and diethylene glycol unit were conventionally contained in PET was found. The polyester was discovered and the present invention was reached. That is, the gist of the present invention is a copolyester having terephthalic acid as a dicarboxylic acid component and ethylene glycol as a main component as a diol component,

(1) 0.5 to 3.0 mol% of isophthalic acid as a dicarboxylic acid component, (2) 1.0 to 2.5 mol% of diethylene glycol as a diol component, (3)
The intrinsic viscosity is 0.60 to 1.50 dl / g, (4) the content of germanium atom is 30 to 60 ppm by weight, and (5) the content of cyclic trimer is 0.35% by weight or less. The present invention relates to a characteristic copolyester, and a molded product made of the same. As a method for producing the copolyester,

A copolymerized polyester having terephthalic acid as a dicarboxylic acid component and ethylene glycol as a main component as a diol component, wherein (1) isophthalic acid is 0.5 to 3.0 mol% as a dicarboxylic acid component, and (2) Diethylene glycol as a diol component is 1.0 to 2.5
Mol%, (3) intrinsic viscosity 0.50 to 0.70 dl /
g, and (4) the content of germanium atoms in the range of 30 to 60 ppm by weight, a solid phase polymerization of a copolyester (hereinafter referred to as "prepolymer") is preferable. Hereinafter, the present invention will be described in detail.

For the terephthalic acid and ethylene glycol as the main components of the copolyester of the present invention, known raw materials used in PET may be used. As the raw material for the isophthalic acid unit, esters such as isophthalic acid, dimethyl isophthalate, and diethyl isophthalate, 5-t
-Butylisophthalic acid, alkyl such as 5-ntylisophthalic acid, nuclear aralkyl, alkoxy, halogen substitution products such as halogen, 5-sulfonylisophthalic acid and sodium salt thereof, and the like. Among these, isophthalic acid or isophthalic acid Dimethyl ester is preferred.

Diethylene glycol (hereinafter referred to as "DE
G)) is partially produced as a by-product from ethylene glycol during the polymerization reaction. Therefore, in addition to the case where a predetermined amount of diethylene glycol or its ester-forming derivative is used as a polymerization raw material, reaction conditions, additives, etc. The content of DEG can be controlled only by making a selection. In particular, in the case of the copolyester of the present invention, the melt polymerization temperature can be lowered by the effect of adding isophthalic acid, and it is easy to keep the DEG amount low. Examples of the additive include tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine, and quaternary hydroxides such as tetraethylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide. Add a small amount of basic compounds such as ammonium and lithium carbonate, sodium carbonate, potassium carbonate, sodium carbonate,
The generation of DEG can be suppressed. On the other hand, when a small amount of an inorganic acid such as sulfuric acid or an organic acid such as benzoic acid is added to the polymerization raw material, the generation of DEG can be promoted and the content can be increased.

Additives for controlling the production amount of these DEGs are usually added to the total amount of the polymerization raw materials in an amount of 0.00
It is used in an amount of 1 to 10% by weight, preferably 0.005 to 1% by weight.

In the copolyester of the present invention, the proportion of isophthalic acid in the total dicarboxylic acid component is 0.5 to 3.0.
Mol%, preferably in the range of 1.0 to 2.5 mol%, and the proportion of DEG in the total diol component is 1.0.
~ 2.5 mol%, preferably 1.2-2.3 mol%,
Is. If the content is less than the range, the effect of reducing oligomers adhering to the mold during molding is small, and the superiority over the conventional PET cannot be recognized. On the other hand, if the content exceeds the range, heat resistance is decreased, which is preferable. In addition, if the amount of isophthalic acid is excessive, the production of oligomers derived from isophthalic acid becomes remarkable, which is not preferable.

Next, the intrinsic viscosity of the copolyester of the present invention is phenol / tetrachloroethane (weight ratio 1 /
0.60 to 1.5 as measured at 30 ° C. in the mixed solvent of 1)
0 dl / g, preferably 0.70 to 1.00 dl / g
Is. When it is less than 0.60 dl / g, when the obtained copolyester is used as a molded article, sufficient strength and elongation cannot be obtained. On the other hand, if it exceeds 1.50 dl / g, the melt viscosity becomes too high, and the shear heat generation in the valve during injection or extrusion molding becomes large, and a large amount of oligomers once reduced is by-produced again. As a result, the contamination of the mold and the like is not improved, which is not preferable.

The content of germanium atom in the copolyester of the present invention is 30 to 60 ppm by weight, preferably 35 to 55 ppm by weight, more preferably 40 to 50 ppm by weight. When the content of germanium atoms is less than the above range, it is not practical because the reduction of the oligomer is slow and the solid phase polymerization rate is slow in the production. On the other hand, when the amount exceeds the above range, the amount of the oligomer by-produced at the time of molding increases, and the effect of improving the mold stain is not sufficient, which is not preferable. This germanium atom is
The thing derived from the germanium compound used as a polymerization catalyst of the below-mentioned copolyester of this invention is taken in into the polymer.

All the above conditions are satisfied, and the content of the cyclic trimer which is the main component of the oligomer is 0.35% by weight.
By providing the copolymerized polyester in an amount of preferably 0.32% by weight or less, and more preferably 0.30% by weight or less, it is possible to improve the contamination of the mold and the like. Even if the content of the cyclic trimer exceeds 0.35% by weight, for example, if it is about 0.40% by weight, some improvement in pollution can be seen, but it cannot be said to be sufficient. Contamination such as mold is noticeable. The above-described copolyester of the present invention is produced by performing melt polymerization and subsequent solid-phase polymerization according to a conventionally known method for PET. Hereinafter, the manufacturing method will be described in detail.

As the melt polymerization method, for example, there is a method in which a direct esterification reaction is performed under pressure using terephthalic acid, isophthalic acid and ethylene glycol, and then the temperature is further raised and the pressure is gradually reduced to carry out a polycondensation reaction. Alternatively, an ester derivative of terephthalic acid, for example, terephthalic acid dimethyl ester, isophthalic acid dimethyl ester, and ethylene glycol are used for transesterification, and then the resulting reaction product is further polycondensed. In these polycondensation reactions, isophthalic acid can be added at any time during the ester reaction, transesterification reaction, or initial stage of the polycondensation reaction. For example, a transesterification reaction between a terephthalic acid ester derivative and ethylene glycol may be performed in advance, and isophthalic acid may be added to the transesterification reaction product for polycondensation.

Such a polycondensation reaction may be carried out in one step or in a plurality of steps. When it is carried out in a plurality of stages, the polycondensation reaction condition is that the reaction temperature of the first stage polycondensation is usually 250 to 290 ° C., preferably 260 to 2
The temperature is 80 ° C., the pressure is usually 500 to 20 Torr, preferably 200 to 30 Torr, and the temperature of the final polycondensation reaction is usually 265 to 300 ° C., preferably 270.
˜295 ° C. and the pressure is usually 10 to 0.1 Torr, preferably 5 to 0.5 Torr.

When the polycondensation reaction is carried out in two steps,
The polycondensation reaction conditions of the first stage and the second stage are within the above ranges, respectively.
The reaction conditions of the polycondensation reaction from the first stage to the one stage before the final stage are those between the reaction conditions of the first stage and the reaction conditions of the final stage.

For example, when the polycondensation reaction is carried out in three stages, the reaction temperature of the second stage polycondensation reaction is usually 2
60 to 295 ° C, preferably 270 to 285 ° C,
The pressure is usually in the range of 50-2 Torr, preferably 40-5 Torr. The intrinsic viscosity reached in each of these polycondensation reaction steps is not particularly limited, but it is preferable that the degree of increase in the intrinsic viscosity in each stage is smoothly distributed, and further from the final stage polycondensation reactor. The intrinsic viscosity of the obtained prepolymer is usually 0.45 to 0.80 dl.
/ G, preferably 0.50 to 0.70 dl / g. If it is above this range, it becomes difficult to form chips, and if it is above this range, it is difficult to extract the prepolymer from the reaction vessel, and the effect of reducing oligomers when subjected to solid phase polymerization is reduced. The obtained prepolymer is
Usually, it is formed into granular chips by melt extrusion.

Such granular chips are usually 2.0 to
It is desirable to have an average particle size of 5.5 mm, preferably 2.2-4.0 mm. In the above esterification reaction, transesterification reaction and polycondensation reaction, an esterification catalyst,
A transesterification catalyst or polycondensation catalyst is used, and a stabilizer is used in some cases.

As the transesterification catalyst, one or more known compounds such as calcium, titanium, manganese, zinc, sodium and lithium compounds can be used, but a manganese compound is particularly preferable from the viewpoint of transparency. A germanium compound is used as the polymerization catalyst. Examples of the germanium compound include oxides of germanium, inorganic acid salts, organic acid salts, halides, sulfides, etc., but other metal catalysts, for example, compounds such as antimony, titanium and cobalt can be used in combination. Is.

The catalyst amount of both the esterification catalyst and the polymerization catalyst is usually 5 to 2000 ppm by weight, preferably 10 to 500 ppm by weight, based on the total amount of the polymerization raw materials. The amount is such that the content of germanium atom in the copolyester of the present invention and the copolyester to be copolymerized in the production thereof is preferably 30 to 60 ppm by weight, more preferably 35 to 55 ppm by weight. It is desirable to use an appropriate amount such that In order to satisfy the range, for example, when using germanium dioxide,
Usually, about 50 to 300 ppm by weight of germanium dioxide as a polymer is used during melt polymerization, but the temperature, pressure, polymerization time at the time of polymerization and the ratio of the dicarboxylic acid component to the glycol component of the esterification reaction product, etc. Can also be controlled by.

As the stabilizer, phosphoric acid esters such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, triphenyl phosphite, trisdodecyl phosphate can be used. Phosphite, phosphite such as trisnonylphenyl phosphite, methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, dibutyl phosphate, monobutyl phosphate, acid phosphate such as dioctyl phosphate and phosphoric acid, phosphite, Phosphorus compounds such as polyphosphoric acid are preferred. The stabilizer is usually 10 to 1000 pp, based on the weight of phosphorus atoms in the stabilizer, in all polymerization raw materials.
m, preferably in the range of 20 to 200 ppm. The phosphorus atom contained in the prepolymer or the copolyester after solid-phase polymerization is usually 0.3 to 1.5 times, preferably 0.4 to 1.0 times by weight ratio with respect to the germanium atom. It is desirable to use it within the range of.

Further, a dicarboxylic acid component other than terephthalic acid and isophthalic acid, and a diol component other than ethylene glycol and diethylene glycol may be contained in a small amount as long as the above-mentioned constitutional requirements of the present invention are not deviated. These dicarboxylic acid components include phthalic acid,
As naphthalene dicarboxylic acid, diphenyl sulfone dicarboxylic acid, 4,4′-biphenyl dicarboxylic acid and structural isomers thereof, aliphatic carboxylic acids such as malonic acid, succinic acid and adipic acid, oxy acids or derivatives thereof,
Examples thereof include p-hydroxybenzoic acid, p-hydroxybenzoic acid ester, glycolic acid and the like. Examples of the diol component include 1,2-bropandiol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol and other aliphatic glycols, cyclohexanediene. Examples thereof include alicyclic glycols such as methanol, and aromatic dihydroxy compound derivatives such as bisphenol A and bisphenol S. An amount that is substantially equivalent to the total diol component and the total dicarboxylic acid component is used.

As described above, the composition (constituent unit) of the prepolymer produced by melt polymerization and the concentration of germanium atom are substantially the same as those of the copolyester of the present invention obtained by subjecting the prepolymer to solid phase polymerization. It is the same. Next, in order to obtain the copolyester of the present invention, it is necessary to further subject the prepolymer chips obtained by the melt polymerization as described above to solid phase polymerization treatment.

The prepolymer chips supplied to the solid phase polymerization may be heated in advance to a temperature lower than the temperature at which the solid phase polycondensation is carried out to carry out precrystallization, and then supplied to the solid phase polycondensation step. .. Such a pre-crystallization step can also be carried out by heating the copolyester chips to a temperature of 120 to 200 ° C., preferably 130 to 180 ° C. for 1 minute to 4 hours in a dry state, or Normally 120 to 200 under steam or steam-containing inert gas atmosphere.
It can also be carried out by heating to a temperature of ° C for 1 minute or more.

The solid-state polymerization step in which the above-mentioned prepolymer chips are supplied comprises at least one stage, and the polymerization temperature is usually 190 to 230 ° C., preferably 195 to 225.
It is carried out under an atmosphere of an inert gas such as nitrogen, argon or carbon dioxide under the conditions of a temperature of 1 ° C. and a pressure of usually 1 kg / cm ² G to 10 Torr, preferably normal pressure to 100 Torr. With respect to the polymerization time, the higher the temperature, the shorter the time it takes to reach the desired physical properties, but usually 1 to 50 hours, preferably 5
-30 hours, more preferably 10-25 hours. The copolymerized polyester of the present invention can be obtained by appropriately selecting the conditions of the above solid mutual polymerization treatment.

The polyester of the present invention thus obtained can be used to form films, sheets, containers, and other packaging materials by the melt molding method generally used in PET. Further, it is possible to improve the mechanical strength by stretching the copolyester at least uniaxially.

In producing a stretched film, the stretching temperature may be set between the glass transition temperature of the copolyester of the present invention and a temperature 70 ° C. higher than that, usually 40 to 170 ° C., preferably 60 to 140 ° C. ℃. The stretching may be uniaxial or biaxial, but biaxial stretching is preferable from the viewpoint of practical physical properties of the film. In the case of uniaxial stretching, the stretching ratio is usually 1.1 to 10 times, preferably 1.5 to
In the case of biaxial stretching, the stretching may be carried out in the range of 8 times, usually 1.1 to 8 times, preferably 1.5 to 5 times in each of the machine direction and the transverse direction. Also, vertical magnification /
The lateral magnification is usually 0.5 to 2, preferably 0.7 to 1.
It is 3. The obtained stretched film is further heat-set,
It is also possible to improve heat resistance and mechanical strength. The heat setting is usually carried out under tension such as compressed air at 120 ° C to the melting point, preferably 150 to 230 ° C, usually for several seconds to several hours, preferably for several tens seconds to several minutes.

In producing a hollow molded article, a preform formed from the copolyester of the present invention is stretch blow molded, and an apparatus conventionally used for PET blow molding can be used. . Specifically, for example, a preform is once molded by injection molding or extrusion molding, and then it is reheated as it is or after processing the plug portion and the bottom portion, and biaxial stretching such as hot parison method or cold parison method. Blow molding method is applied. In this case, the molding temperature, specifically, the temperature of each part of the cylinder and nozzle of the molding machine can be set in the range of 260 to 280 ° C., which is lower than that of general PET by 1 to 10 ° C., and the amount of oligomers can be kept low. Is easy. Further, it is possible to suppress the decrease in the intrinsic viscosity to be low, and it is also easy to suppress the amount of acetaldehyde produced as a by-product to be low.
The stretching temperature is usually 70 to 120 ° C., preferably 80 to 1
At 10 ° C., the draw ratio is usually 1.5 to 3.5 in the machine direction.
2 times to the circumference requirement.

The obtained hollow molded product can be used as it is, but in the case of a content liquid such as fruit juice drink and oolong tea which requires hot filling, it is generally further heat-set in a blow mold. Further, it is used by further imparting heat resistance. Heat fixation is usually 100 to 200 under tension such as compressed air.
C., preferably 120 to 180.degree. C., for a few seconds to a few hours, preferably a few seconds to a few minutes.

[0034]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist. Various measuring methods used in this example are shown below. The method for measuring the intrinsic viscosity is as described above.

(1) Amount of isophthalic acid (hereinafter referred to as "IPA amount")
Say. ) Methanol was decomposed by a conventional method, and the produced dimethyl ester component was quantified by gas chromatography.

(2) Amount of diethylene glycol (hereinafter referred to as "D
EG amount ”. ) Hydrolysis was carried out by an ordinary method, and the produced diol component was quantified by gas chromatography.

(3) Amount of cyclic trimer (hereinafter referred to as "CT amount") 200 mg of a copolymerized polyester sample was added to chloroform /
It was dissolved in 2 ml of a mixed solution of hexafluoroisopropanol (volume ratio 3/2) and further diluted with 20 ml of chloroform. To this, 10 ml of methanol was added to reprecipitate a sample, and a filtrate after filtration was obtained. After drying the filtrate to dryness,
A liquid obtained by dissolving the residue in 25 ml of dimethylformamide was quantified by liquid chromatography.

(4) Terminal carboxy group concentration (hereinafter referred to as "A
V ”. ) 100 mg of the copolyester sample was dissolved by heating in 5 ml of benzyl alcohol, and 5 ml of chloroform was added to the solution to dilute it, and then phenol red was used as an indicator to give a 0.1.
It was titrated with a 1N-sodium hydroxide / benzyl alcohol solution to quantify it.

(5) Germanium atom content (hereinafter referred to as "G
e amount ”. ) A 2.0 g sample of the copolyester was ashed by a conventional method under a sulfuric acid storage condition, completely decomposed, and then made up to a volume of 100 ml with distilled water.

(6) Phosphorus atom content (hereinafter referred to as "P amount") It was analyzed and quantified by an emission spectroscopic analysis method in the same manner as the analysis of the germanium atom content.

(7) Inert gas flow rate The inert gas flow rate is expressed as a volume amount (L) obtained by converting the amount of gas flowing per unit time (hr) and per unit resin weight (kg) to 1 atm and 25 ° C. It was

Example 1 12.7 kg of terephthalic acid, 0.263 k of isophthalic acid
g and ethylene glycol 5.82 kg slurry was prepared, 0.30 kg of bis (β-hydroxyethyl) terephthalate was added in advance, and they were sequentially supplied over 4 hours in an esterification tank kept at 250 ° C.

After completion of the feeding, the esterification reaction was allowed to proceed for 1 hour, and then half of the amount was transferred to a polycondensation tank to obtain 1.14 g of phosphoric acid.
(To polymer 150 wt ppm) and germanium dioxide 0.91 g (to polymer 120 wt ppm) were charged, and the temperature was gradually raised from 250 ° C. to 280 ° C.,
The pressure was gradually reduced from normal pressure and maintained at 0.5 mmHg. After the reaction was carried out for 3 hours, CT0.9 was obtained by melt extrusion.
4% by weight, intrinsic viscosity 0.56 dl / g, AV24eq /
A prepolymer chip having a ton, a Ge content of 43 weight ppm and a P content of 23 weight ppm was obtained.

Next, the surface of the prepolymer chip was crystallized at 150 ° C. with a stirring crystallization machine (manufactured by Bepex), and then transferred to a stationary solid phase polymerization tower, and 20 l / kg-hr of nitrogen was added. Under circulation, dry at about 150 ° C for 3 hours and then at 208 ° C for 2 hours.
Solid phase polymerization was performed for 0 hours to obtain a solid phase polymerization chip. Table 1 shows the main physical properties of the solid-state polymerized chip. The solid-state polymerized chip had AV13eq / ton.

Next, using the solid-state polymerization chip, each cylinder and nozzle temperature 275 ° C., screw rotation speed 100 rpm, injection time 10 seconds, mold cooling water temperature 10 ° C. injection molding machine manufactured by Toshiba Corp. A preform was molded with IS-60B. After the mouthpiece of this preform was heated and crystallized by a self-made crystallization machine, it was blow-molded by a stretch blow molding machine set at a preheating furnace temperature of 90 ° C., a blow pressure of 20 kg / cm ³ , and a molding cycle of 10 seconds. Part average wall thickness 3
A bottle having a diameter of 00 μm and an internal volume of 11 was prepared, and subsequently, heat-fixed for 10 seconds in a mold set at 150 ° C. under compressed air tension. Table 1 shows the physical properties of the bottle. Although 1000 bottles were continuously molded, no contamination was found in any of the injection molding, stretch blow molding, and heat setting molds.

Further, the above-mentioned bottle was filled with the orange juice liquid sterilized at 90 ° C. and allowed to cool to 85 ° C., and the bottle was tightly closed and then inverted for 15 minutes. However, liquid leakage, spouts, shoulders and body etc. No deformation was observed.

Example 2 The prepolymer chip obtained in Example 1 was used in Example 1
In the same manner as above, solid mutual polymerization was carried out at 215 ° C. for 20 hours to obtain a solid phase polymerization chip. The main physical properties of the solid-state polymerized chip are shown in Table-
Shown in 1. The solid-state polymerization chip is AV10eq /
It was ton.

Then, the solid-state polymerized chip was obtained in the same manner as in Example 1 except that the temperature of each cylinder of the injection molding machine and the nozzle temperature were changed to 265 ° C. to obtain a heat-fixing bottle having a capacity of 1 liter. The physical properties of the bottle are shown in Table-1. Further, the bottle was completely good in appearance without whitening. Further, no contamination of the mold was observed even when the continuous operation was performed as in Example 1. Furthermore, no change was observed in the bottle in the heat filling test carried out in the same manner as in Example 1.

Example 3 14.85 kg of dimethyl terephthalate, 0.15 kg of dimethyl isophthalate, 10.6 kg of ethylene glycol
Then, 2.60 g of manganese acetate / tetrahydrate was charged into the reaction vessel, and the temperature was gradually raised from 160 ° C. to 220 ° C. over 4 hours for esterification. Phosphoric acid 2.67 was added to the reaction product.
g, 1.78 g of germanium dioxide, and finally 2
C at 0.5 ° C. under 0.5 Torr, polymerization time 3 hours, C
T amount 0.97% by weight, intrinsic viscosity 0.58 dl / g, AV
A prepolymer having a content of 16 eq / ton, a Ge content of 48 weight ppm and a P content of 30 weight ppm was obtained.

Then, in the same manner as in Example 1, 2 at 208.degree.
Solid phase polymerization was performed for 0 hours to obtain a solid phase polymerization chip. The main physical properties of the solid-state polymerized chip are shown in Table 1. The solid-state polymerized chip had an AV7eq / ton. From this chip, in the same manner as in Example 1, a heat-fixing bottle having an capacity of 11 was obtained.
The physical properties of the bottle are shown in Table-1. Further, no contamination of the mold was observed even when the continuous operation was performed as in Example 1. Furthermore, no change was observed in the bottle in the heat filling test carried out in the same manner as in Example 1.

Example 4 The reaction was performed in the same manner as in Example 1 except that 0.197 kg of isophthalic acid and 1.10 g of germanium dioxide were used, and the CT amount was 0.96% by weight and the intrinsic viscosity was 0.57 dl.
/ G, AV20eq / ton, Ge amount 53 weight ppm,
A prepolymer having a P content of 27 ppm by weight was obtained. Then, in the same manner as in Example 1, solid phase polymerization was carried out at 208 ° C. for 20 hours to obtain a solid phase polymerization chip. Table 1 shows the main physical properties of the solid-state polymerized chip. The solid-state polymerization chip is AV11eq /
It was ton.

In the same manner as in Example 1 from this solid-state polymerization chip, a heat-fixing bottle having 11 volumes was obtained. Table 1 shows the physical properties of the bottle.
Shown in. Further, no contamination of the mold was observed even when the continuous operation was performed as in Example 1. Furthermore, no change was observed in the bottle in the heat filling test carried out in the same manner as in Example 1.

Further, using this chip, a sheet having a wall thickness of 300 μm was molded by a 30 mmφ extruder in which the temperature of each part of the cylinder and nozzle was 275 ° C., the screw rotation speed was 40 rpm, and the extrusion rate was 80 g / min. 1 continuously
The extrusion molding was continued for 0 hours, but the cooling drum was not contaminated. Furthermore, this extruded sheet is placed in a tank at 90 ° C.
With a long stretching machine (TM Long) set to 3
X 3 times simultaneously biaxially stretched, then under tension in the oven,
The film was heat set at 200 ° C. for 120 seconds to obtain a stretched film having a thickness of 100 μm. The film has an intrinsic viscosity of 0.74 dl
/ G, CT was 0.30% by weight.

Comparative Example 1 The same operation as in Example 1 was carried out except that isophthalic acid was not added, CT 1.01% by weight, intrinsic viscosity 0.56 dl
/ G, AV24eq / ton, Ge amount 43 ppm by weight,
A prepolymer having a P content of 24 ppm by weight was obtained. Next, in the same manner as in Example 1, solid phase polymerization was carried out at 208 ° C. for 20 hours to obtain solid interpolymerization chips. Table 1 shows the main physical properties of the solid-state polymerized chip. In addition, the solid-state polymerization chip is AV13eq
Was / ton.

Table 1 shows the physical properties of a 1 l capacity heat-fixing bottle obtained from this chip in the same manner as in Example 1. In addition, the same hot-filling test results as in Example 1 were good for this bottle, but when a mold after molding was observed as a continuous molding test, a thin white film-like deposit was observed.

Comparative Example 2 The prepolymer obtained in Comparative Example 1 was solid-phase polymerized at 208 ° C. for 30 hours in the same manner as in Example 1 to obtain a solid-phase polymerized chip. Table 1 shows the main physical properties of the solid-state polymerized chip. Further, the solid-state polymerization chip is AV10 eq / ton
Met. Table 1 shows the physical properties of the heat-fixing bottle having a volume of 1 liter obtained from the solid-state polymerization chip in the same manner as in Example. Further, although the same result of the heat filling test as in Example 1 was good for the bottle, a thin white film-like deposit was observed when the mold after the molding was observed as a continuous molding test.

Further, a preform was molded from the solid-state polymerized chip in the same manner as in Example 1 except that the temperature of each cylinder of the injection molding machine and the nozzle temperature were 270 ° C. However, the obtained preform was white and opaque and could not be molded normally.

Comparative Example 3 The reaction was performed in the same manner as in Example 1 except that 0.45 g of germanium dioxide was used, and the CT amount was 0.94% by weight, the intrinsic viscosity was 0.56 dl / g, AV23 eq / ton, and Ge amount was 2
A prepolymer having a content of 5 ppm by weight and a P content of 20 ppm by weight was obtained. Then, in the same manner as in Example 1, solid phase polymerization was carried out at 208 ° C. for 20 hours. Table 1 shows the main physical properties of the solid-state polymerized chip. The solid-state polymerization chip was AV13eq / ton.

From this chip, in the same manner as in Example 2,
A 1 liter capacity heat set bottle was obtained. The physical properties of the bottle are shown in Table-1. Further, although the same result of the heat filling test as in Example 1 was good for the bottle, a thin white film-like deposit was observed when the mold after the molding was observed as a continuous molding test.

Comparative Example 4 The reaction was performed in the same manner as in Example 1 except that 1.37 g of germanium dioxide was used, and the CT amount was 0.94% by weight, the intrinsic viscosity was 0.56 dl / g, the AV24 eq / ton, and the Ge amount. A prepolymer having a weight content of 65 ppm and a P content of 36 ppm was obtained. Then, in the same manner as in Example 1, solid phase polymerization was carried out at 208 ° C. for 20 hours. Main physical properties of the solid-state polymerization chip are shown in Table-1. The AV of the solid-state polymerized chip was 13 eq / ton.

From this chip, in the same manner as in Example 2,
A 1 liter capacity heat set bottle was obtained. The physical properties of the bottle are shown in Table-1. Further, although the same result of the hot filling test as in Example 1 was obtained in the bottle, the mold after the molding was observed as a continuous molding test. As a result, a thin white film-like deposit was observed.

Comparative Example 5 0.35 kg of diethylene glycol was added to the prepared slurry.
The same operation as in Example 1 except that the CT amount was 0.8
8 wt%, intrinsic viscosity 0.58 dl / g, AV23eq /
A prepolymer having a ton amount of Ge of 43 wt ppm and a P amount of 23 wt ppm was obtained. Next, as in Example 1, 20
Polymerization was carried out at 8 ° C for 20 hours. Table 1 shows the main physical properties of the polymerized chips. Further, the solid-state polymerization chip is AV11e.
It was q / ton. Table 1 shows the physical properties of a 1 l capacity heat-fixing bottle obtained from this chip in the same manner as in Example 1.
Further, in the continuous molding test, adhesion of a thin white film to the mold surface was confirmed. Further, in the heat filling test, deformation of the bottle and liquid leakage from the spout were observed.

Comparative Example 6 12.5 kg of terephthalic acid, 0.814 k of isophthalic acid
g, ethylene glycol 6.31 kg and bis-β-
The same operation as in Example 1 was carried out except that 0.3 kg of hydroxyethyl terephthalate was used, and the CT amount was 0.88% by weight, the intrinsic viscosity was 0.58 dl / g, and the AV24 eq / to.
A prepolymer having n, Ge content of 43 weight ppm and P content of 24 weight ppm was obtained. Next, in the same manner as in Example 1, 208
Solid-state polymerization was performed at 20 ° C. for 20 hours. Table 1 shows the main physical properties of the solid-state polymerized chip. The solid-state polymerization chip is AV11e
It was q / ton. In addition, only in the case of this example, several hundred ppm of a cyclic dimer based on isophthalic acid was observed in addition to the cyclic trimer as the oligomers.

From this chip, the same operation as in Example 1 was carried out,
A 1 liter capacity heat set bottle was produced. The physical properties of the bottle are shown in Table-1. Further, in the same continuous molding test as in Example 1, almost no contamination of the mold was observed, but when the heat filling test was carried out, the entire bottle was deformed and a small amount of liquid leaked from the spout part was observed. Was given.

[0065]

[Table 1]

[0066]

EFFECT OF THE INVENTION The copolymerized polyester of the present invention has a low oligomer content and is less likely to cause mold contamination during molding. Therefore, since it is not necessary to frequently wash the molding device when manufacturing the molded product, it is possible to improve the productivity of the molded product such as a bottle, a film or a sheet. Moreover, the copolyester of the present invention is excellent in heat resistance and mechanical strength and is suitable as a molding material for containers for fruit juice drinks requiring heat resistance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display area C08J 5/18 CFD 9267-4F // B29K 67:00 B29L 22:00 4F C08L 67:02 (72 ) Inventor Osamu Kishiro Sanryo Kasei Co., Ltd. Research Institute, 1000, Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa

Claims (4)

[Claims] 1. A copolymerized polyester mainly comprising terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component, wherein (1) isophthalic acid is 0.5 to 3.0 mol% as a dicarboxylic acid component,
(2) Diethylene glycol as the diol component is 1.
0-2.5 mol%, (3) intrinsic viscosity 0.60-1.5
0 dl / g, (4) germanium atom content of 30 ~
60 weight ppm, the content of (5) cyclic trimer is 0.35
A copolymerized polyester, characterized in that the content of the polyester is less than or equal to wt%. 2. A copolymerized polyester mainly comprising terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component, wherein (1) isophthalic acid is 0.5 to 3.0 mol% as a dicarboxylic acid component,
(2) Diethylene glycol as the diol component is 1.
0-2.5 mol%, (3) intrinsic viscosity 0.50-0.7
0 dl / g, (4) germanium atom content of 30 ~
The copolyester of claim 1 produced by solid state polymerizing a prepolymer of 60 ppm by weight. 3. A copolymer polyester hollow container obtained by subjecting the copolymer polyester according to claim 1 to preform molding by injection molding or extrusion molding, and then biaxially stretch blow molding. 4. A stretched film made of a copolyester, which is obtained by stretching the sheet-like material according to claim 3 in at least one direction.