JP3459430B2 - Copolyester and hollow container and stretched film comprising the same - Google Patents

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 that has a low content of oligomers that are unlikely to cause contamination of molds and the like during molding, and that is excellent in productivity, heat resistance, mechanical strength, and the like, and a molded product thereof.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter,
"PET") has excellent mechanical strength, chemical stability, transparency, hygiene, and the like, and is lightweight and inexpensive, so it is widely used as various sheets and containers for packaging materials. The growth as a container for carbonated drinks, fruit juice drinks, liquid seasonings, edible oil, liquor and wine is remarkable.

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 that requires hot filling such as a fruit juice beverage, it is generally molded in a bottle by further heat fixing in the 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. Content of ~ 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 roughness and whitening of the molded product. 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, there are many known copolyesters having properties similar to PET, for example, copolyesters using terephthalic acid and isophthalic acid as dicarboxylic acid components, and copolyesters using ethylene glycol and diethylene glycol as glycol components. Has been. However,
The amount of oligomer is reduced to a certain extent or more, and PET
A copolyester having physical properties equivalent to or higher than that has not been specifically known.

[0006]

DISCLOSURE OF THE INVENTION The object of the present invention is to prevent contamination of molds and the like during molding, the content of oligomers is small, the by-product of oligomers during molding is also small, and more than or equal to that of conventional PET. Another object of the present invention is to provide a highly productive copolyester having high heat resistance.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that the conventional PET has a specific physical property range in which a small amount of cyclohexanedimethanol units and diethyleneglycol units are contained in conventional PET. The inventors have found a polymerized polyester and reached the present invention. That is, the gist of the present invention is a copolymerized polyester containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a main component as a diol component, and (1) as a diol component, cyclohexanedimethanol is 0.5 to 3.5. Mol%, diethylene glycol 1.0-2.5 mol%,
(2) Intrinsic viscosity of 0.60 to 1.50 dl / g, (3)
The terminal carboxyl group concentration is 18 eq / ton or less,
(4) The present invention relates to a copolyester having a cyclic trimer content of 0.35% by weight or less, and a molded article made of the copolyester. The method for producing the copolymerized polyester includes terephthalic acid as a dicarboxylic acid component,
A copolymerized polyester having ethylene glycol as a main component as a diol component, wherein (1) cyclohexanedimethanol is 0.5 to 3.5 mol% and diethylene glycol is 1.0 to 2.5 mol% as a diol component,
(2) Intrinsic viscosity of 0.50 to 0.70 dl / g, (3)
Copolymerized polyester having a terminal carboxyl group concentration of 15 to 30 eq / ton or less (hereinafter referred to as “prepolymer”)
Say. The method of carrying out solid-state polymerization of is preferable.

The present invention will be described in detail below. As 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. Further, as the cyclohexanedimethanol raw material of the present invention, 1,2-, 1,3, and 1,
4-Cyclohexanedimethanol can be mentioned, and its cis and trans isomer ratio may be a mixture in any ratio. Of these, 1,4-cyclohexanedimethanol is usually used, and the cis / trans ratio is (10 to 50) / (90 to 5).
Those having a ratio of 0) are particularly preferably used.

Diethylene glycol (hereinafter referred to as "DE
G)) is partly 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 appropriately selecting. Particularly in the case of the copolyester of the present invention, the melt polymerization temperature can be lowered by the effect of adding cyclohexanedimethanol, and the DEG amount can be easily kept low. Examples of the additive include tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine, quaternary hydroxides such as tetraethylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide. Generation of DEG can be suppressed by adding a small amount of basic compounds such as ammonium and lithium carbonate, sodium carbonate, potassium carbonate, sodium acetate. On the other hand, if 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 is promoted,
The content can also be increased.

Additives for controlling the amount of DEG produced are usually added to the total amount of the polymerization raw materials in an amount of 0.00
1 to 10% by weight, preferably 0.005 to 1% by weight is used. In the copolyester of the present invention, the ratio of cyclohexanedimethanol in all diol components is 0.5.
˜3.5 mol%, preferably 1.0 to 2.5 mol%, and the proportion of DEG in the total diol component is 1.
It is 0 to 2.5 mol%, preferably 1.2 to 2.3 mol%.

If the amount is less than the above range, the effect of reducing oligomers adhering to the mold during molding is small and the conventional PET is not used.
The above superiority is not recognized. On the other hand, if the content exceeds the above range, the heat resistance is lowered, which is not preferable, and particularly the
In the case of an excess of crohexanedimethanol , cyclohexane
It is not preferable because oligomers derived from xanthymethanol are remarkably produced.

Next, the intrinsic viscosity of the copolyester of the present invention is phenol / tetrachloroethane (weight ratio 1 /
Measured in the mixed solvent of 1) at 30 ° C.,
1.50 dl / g, preferably 0.70-1.00 d
1 / g. When it is less than 0.60 dl / g, when the obtained copolyester is used as a molded article, it cannot have a sufficient strength and elongation. 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, so that a large amount of oligomers once reduced is by-produced again. As a result, the improvement of contamination of the mold is not observed, which is not preferable.

Further, the concentration of the terminal carboxy group of the copolyester of the present invention is 18 eq / ton or less, preferably 15 eq / ton or less. If the concentration of the terminal carboxy group exceeds the above range, the effect of reducing the oligomers attached to the mold or the like at the time of molding is small, and the moisture resistance and thermal stability also deteriorate, which is not preferable.

All of 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 when the content of the cyclic trimer exceeds 0.35% by weight, for example, when 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, a direct esterification reaction is performed under pressure using terephthalic acid, ethylene glycol and cyclohexanedimethanol, and then,
There is a method of increasing the temperature and gradually reducing the pressure to cause a polycondensation reaction. Alternatively, an ester derivative of terephthalic acid,
For example, it can be produced by subjecting dimethyl terephthalate to an ester exchange reaction using ethylene glycol and cyclohexanedimethanol to carry out an exchange reaction, and then subjecting the obtained reaction product to polycondensation. In these polycondensation reactions, cyclohexanedimethanol can be added at any stage of the esterification reaction, transesterification reaction, or initial stage of the polycondensation reaction, but is preferably the initial stage of the ester reaction or transesterification reaction.

Such a polycondensation reaction may be carried out in one step or in a plurality of steps. When 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 290 ° C.
280 ° 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 to 295 ° C., 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 each within the above range, and when the polycondensation reaction is carried out in three or more stages,
The reaction conditions of the polycondensation reaction from the 1st stage to the 1st stage before the final stage are the conditions between the reaction conditions of the 1st stage and the reaction conditions of the final stage.

For example, when the polycondensation reaction is carried out in three stages, the reaction temperature for the second stage polycondensation reaction is usually 2
It is 60-295 ° C, preferably 270-285 ° C and the pressure is usually in the range 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 polycondensation reactor at the final stage. 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 the amount is less than the above range, it is difficult to form chips, and if the amount is more than the above range, it is difficult to extract the prepolymer from the reaction vessel, and the effect of reducing the oligomer in the solid phase polymerization is reduced. The obtained prepolymer is usually formed into granular chips by melt extrusion.

Such granular chips usually have a particle size of 2.0 to
It is desirable to have an average particle size of 5 mm, preferably 2.2-4.0 mm. In the above esterification reaction, transesterification reaction and polycondensation reaction, it is preferable to use an esterification catalyst, a transesterification catalyst, a polycondensation catalyst, a stabilizer and the like.

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. As the polymerization catalyst, one or more known germanium, antimony, titanium and cobalt compounds can be used, but a germanium compound is preferably used. The amount of the catalyst, as both the esterification catalyst and the polymerization catalyst, is usually 5 to 2000 p as the amount of metal in all the polymerization raw materials.
pm, preferably in the range of 10 to 500 ppm.

If the germanium compound is further specified, the compound is germanium oxide,
Inorganic acid salts, organic acid salts, halides, sulfides, etc. are exemplified, and the amount thereof is such that the germanium atom is usually 10 to 100 ppm by weight in the prepolymer to be produced or the copolyester after solid-phase polymerization. Preferably 30-6
It is preferable to use it so as to contain 0 ppm by weight, from the viewpoint of suppressing oligomer by-product and thermal stability.

The stabilizers include phosphoric acid esters such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, triphenyl phosphite and trisdodecyl phosphate. Phosphite such as phyto, trisnonyl phenyl 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 wt. P as the weight of phosphorus atom in the stabilizer in all the polymerization raw materials.
pm, preferably in the range of 20 to 200 ppm by weight. In particular, when a germanium compound is used as the polymerization catalyst, the phosphorus atom contained in the prepolymer or the copolyester after solid-phase polymerization is usually 0.3 to 1 in weight ratio with respect to the germanium atom. .5 times,
It is desirable to use it in a range of preferably 0.4 to 1.0 times.

Further, a dicarboxylic acid component other than terephthalic acid and a diol component other than ethylene glycol, cyclohexanedimethanol, 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. Examples of these dicarboxylic acid components include isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, 4,4′-biphenyldicarboxylic acid and structural isomers thereof, aliphatic acids such as malonic acid, succinic acid, and adipic acid. Examples of the carboxylic acid, the oxy acid or the derivative thereof include p-hydroxybenzoic acid, p-hydroxybenzoic acid ester and glycolic acid. Further, as the diol component, 1,
2-bropandiol, 1,3-propanediol,
1,4-butanediol, pentamethylene glycol,
Hexamethylene glycol, neopentyl glycol,
Examples thereof include aliphatic glycols such as diethylene glycol, alicyclic glycols such as cyclohexanediethanol, 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 (constitutional unit) of the prepolymer produced by melt polymerization is substantially the same as that of the copolyester of the present invention obtained by subjecting the prepolymer to solid phase polymerization. The concentration of the terminal carboxyl group in the prepolymer is usually 15 to 30 eq / t.
on, preferably 18 to 25 eq / ton. If it is less than the above range, the solid phase polymerizability is poor and it takes a long time to increase the intrinsic viscosity, which is not preferable. When the amount exceeds the above range, the effect of reducing oligomers when subjected to solid phase polymerization is small.

Next, in order to obtain the copolyester of the present invention, it is necessary to subject the prepolymer chips obtained by the melt polymerization as described above to further 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 performed to perform pre-crystallization, and then supplied to the solid phase polycondensation step. Such a pre-crystallization step can be carried out by heating the copolyester chips in a dry state, usually at a temperature of 120 to 200 ° C, preferably 130 to 180 ° C for 1 minute to 4 hours, or The chips are usually heated to 120 to 200 ° under steam or an inert gas atmosphere containing steam.
It can also be performed by heating to the temperature of C for 1 minute or more.

The solid-state polymerization step in which chips of the prepolymer as described above are supplied comprises at least one step, and the polymerization temperature is usually 190 to 230 ° C, preferably 195 ° C to.
It is 225 ° C, and the pressure is usually 1 kg / cm ² G to 1
It is carried out under an atmosphere of an inert gas such as nitrogen, argon or carbon dioxide under the conditions of 0 Torr, preferably atmospheric pressure to 100 Torr. The higher the temperature, the shorter the polymerization time to reach the desired physical properties, but it is usually 1 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 25 hours.

The copolymerized polyester of the present invention can be obtained by appropriately selecting the conditions of the above solid phase polymerization treatment. The polyester of the present invention thus obtained can be used to form films, sheets, containers, and other packaging materials by using a melt molding method generally used in PET. Further, the mechanical strength can be improved by stretching the copolyester in at least a uniaxial direction.

The stretched film made of the polyester of the present invention includes a uniaxially stretched film, which is usually used for stretching PET, a sheet-shaped product obtained by injection molding or extrusion molding, sequential biaxial stretching, and simultaneous biaxial stretching. It is molded using any stretching method of. Moreover, it is also possible to form into a cup shape or a tray shape by pressure forming or vacuum forming.

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. ~ 140 ° C. The stretching may be uniaxial or biaxial, but biaxial stretching is preferable from the viewpoint of practical physical properties of the film. The stretching ratio is usually 1.1 to 10 times in the case of uniaxial stretching, preferably 1.5 to 8 times, and in the case of biaxial stretching,
It is usually 1.1 to 8 times, preferably 1.5 to 5 times in each of the vertical direction and the horizontal direction. Further, the vertical magnification / horizontal magnification is usually 0.5 to 2, preferably 0.7.
~ 1.3. The obtained stretched film can be further heat-fixed to improve heat resistance and mechanical strength. The heat setting is usually carried out under tension such as compressed air at 120 ° C to a 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 in 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. The molding temperature in this case, specifically, the temperature of each part of the cylinder and nozzle of the molding machine is usually 260 to 280 ° C.
In this range, the temperature can be set lower by 1 to 10 ° C than in the case of general PET, and it is easy to keep the amount of oligomer low.
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 8
At 0 to 110 ° C, the draw ratio is usually 1.5 in the machine direction.
˜3.5 times, and 2 to 5 times in the circumferential direction.

The obtained hollow molded article can be used as it is, but in the case of a content liquid such as fruit juice 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.
It is carried out at ° C, preferably 120 to 180 ° C, for several seconds to several hours, preferably for several seconds to several minutes.

[0033]

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 measurement of the intrinsic viscosity is as described above. (1) Cyclohexanedimethanol amount (hereinafter “CHDM
Quantity. ) After methanolysis by a conventional method, the produced dimethyl ester component was quantified by gas chromatography. (2) Diethylene glycol amount (hereinafter referred to as "DEG amount") Hydrolysis was carried out by a conventional method, and the produced diol component was quantified by gas chromatography. (3) Cyclic trimer amount (hereinafter referred to as "CT amount") 200 mg of a copolyester 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 analyzed and quantified by liquid chromatography. (4) Terminal carboxyl group concentration (hereinafter referred to as “AV”) 100 mg of a copolymerized polyester sample was dissolved by heating in 5 ml of benzyl alcohol, and 5 ml of chloroform was added to the solution to dilute it.
It was titrated with a 1N-sodium hydroxide / benzyl alcohol solution to quantify it. (5) Germanium atom content (hereinafter referred to as “Ge amount”) About 2.0 g of a copolyester sample was ashed by a conventional method in the presence of sulfuric acid, completely decomposed, and then fixed to 100 ml with distilled water, It was quantified by emission spectroscopy. (6) Phosphorus atom content (hereinafter referred to as "P amount") It was quantified by the 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 the amount of gas flowing per unit time (hr) and per unit resin weight (kg) at 1 atm and 25 ° C.
The volume amount (L) converted to (8) Strength and elongation characteristics According to JIS K7113, temperature 23
Tensile strength meter (made by INTESCO) at ℃ and 50% humidity
It was measured by.

[0034]

Example 1 13.0 kg of terephthalic acid, 1,4-cyclohexanedimethanol (cis / trans = 30/7)
0) 0.27 kg, and ethylene glycol 5.82
Prepare 0.30 kg of bis (β
-Hydroxyethyl) terephthalate was added, 250
It was sequentially supplied to the esterification tank kept at ° C over 4 hours. 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, where phosphoric acid (1.15 g, polymer 150 ppm) and germanium dioxide (0.92) were added.
g (to 120 ppm of polymer) was charged, the temperature was gradually raised from 250 ° C. to 278 ° C., the pressure was gradually reduced from normal pressure, and the pressure was maintained at 0.5 mmHg. After the reaction was performed for 3 hours, by melt extrusion molding, CT 0.93% by weight, intrinsic viscosity 0.54 dl / g, AV24 eq / ton, Ge
Prepolymer chips having an amount of 43 weight ppm and a P amount of 23 weight ppm were obtained.

Next, the surface of the prepolymer chip was crystallized at 150 ° C. with a stirring crystallizer (manufactured by Bepex), and then transferred to a stationary solid phase polymerization tower, and 20 l / kg-hr of nitrogen was added. Under circulation, after drying at 140 ° C for 3 hours, 210 ° C
Solid-state polymerization was carried out for 20 hours to obtain a solid-state polymerization chip. Table 1 shows the physical properties of the solid-state polymerization chip. The solid-state polymerized chip had a Ge content of 43 weight ppm and a P content of 23 weight ppm.

Next, using the solid-state polymerization chip, each cylinder and nozzle temperature is 275 ° C., screw rotation speed is 100 rpm, injection time is 10 seconds, mold cooling water temperature is 10 °.
The preform was molded by the Toshiba molding injection molding machine IS-60B set to C. After heating and crystallizing the plug part of this preform with a self-made crystallizer, the preheating furnace temperature was 90 °.
C, blow pressure was 20 kg / cm ² , and blow molding was performed by a stretch blow molding machine set to a molding cycle of 10 seconds to obtain a bottle having an average wall thickness of 300 μm and an internal volume of 11, and subsequently 150
It was heat-set in a mold set at ° C for 10 seconds under compressed air tension. The physical properties of the bottle are shown in Table 1. Also, 1000
Bottles of books were continuously molded, but injection molding, stretch blow molding,
No contamination was observed in either the heat-set mold or the heat-set mold.

Further, the above-mentioned bottle was filled with the orange juice liquid which had been sterilized at 90 ° C. and allowed to cool to 85 ° C., and after sealing, 15
Although it was placed upside down for a minute, no liquid leakage or deformation of the mouth plug, shoulder, or body was observed. Further, using the solid-state polymerization chip, the temperature of each part of the cylinder and the nozzle is controlled to 2
75 ° C, screw rotation speed 40 rpm, extrusion rate 80 g /
A sheet having a wall thickness of 300 μm was molded by a 30 mm diameter extruder set to minutes. The extrusion molding was continuously continued for 10 hours, but the contamination of the cooling drum was hardly recognized.

Further, this extruded sheet was biaxially stretched simultaneously 3 × 3 times with a long stretching machine (manufactured by TM Long Co.) set at 90 ° C. in a tank, and then, under tension, in an oven, 200
The film was heat set at 120 ° C. for 120 seconds to obtain a stretched film having a thickness of 100 μm. This stretched film has an intrinsic viscosity of 0.77 dl
/ G, CT amount was 0.42% by weight.

On the other hand, the sheet temperature is set to 120
℃, compressed air 4.0kg / cm ² , vacuum ℃ 500mmHg,
A sheet-shaped thin-walled container was manufactured using a compressed air vacuum forming machine (manufactured by Asano Laboratory Co., Ltd.) set to a cooling mold of 40 ° C. The yield strength of the container piece was 570 kg / cm ² , and the breaking strength was 7
It was 20 kg / cm ² , the intrinsic viscosity was 0.77 dl / g, and the CT amount was 0.41% by weight. The PET thin-walled containers of Comparative Examples 1 and 2 exhibited mechanical strength equivalent to that of the PET thin-walled containers, while the CT amount significantly decreased.

[0040]

Example 2 The prepolymer chip obtained in Example 1 was subjected to solid phase polymerization at 215 ° C. for 20 hours in the same manner as in Example 1 to obtain a solid phase polymerization chip. Table 1 shows the physical properties of the solid-state polymerization chip. The solid-state polymerized chip had a Ge content of 43 weight ppm and a P content of 23 weight ppm.

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 temperature of the nozzle were 267 ° C. to obtain a heat-fixing bottle having a capacity of 1 liter. The physical properties of the bottle are shown in Table-1. In addition, the bottle was completely good in appearance without whitening. Further, even when the continuous operation was performed as in Example 1, the mold was not contaminated. Furthermore, no change was observed in the bottle in the heat filling test carried out in the same manner as in Example 1.

[0042]

Example 3 Dimethyl terephthalate 7.5 kg, 1,4
-Cyclohexanedimethanol (cis / trans = 40
/ 60) 0.25 kg, ethylene glycol 4.66 k
g and 1.39 g of manganese acetate tetrahydrate were charged into a reaction vessel, and the temperature was gradually raised from 160 ° C. to 220 ° C. over 4 hours to effect esterification. Phosphoric acid 2.
67 g and antimony trioxide 2.87 g were added, and finally, at 275 ° C. under 0.5 Torr, the polymerization time was 3 hours,
CT amount 0.87% by weight, intrinsic viscosity 0.60 dl / g, A
A prepolymer of V15eq / ton was obtained.

Then, in the same manner as in Example 1, 210 ° C.
Solid-state polymerization was carried out for 20 hours to obtain a solid-state polymerization chip. Table 1 shows the physical properties of the solid-state polymerization chip. In the same manner as in Example 1 from this chip, a heat-fixing bottle having 11 volumes 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. Further, in the hot filling test carried out in the same manner as in Example 1, almost no change was observed in the bottle.

[0044]

Example 4 0.22 kg of 1,4-cyclohexanedimethanol (cis / trans = 30/70), 5.83 kg of ethylene glycol, 1.13 g of germanium dioxide.
Except that the polycondensation reaction was performed in the same manner as in Example 1 except that
CT amount 0.95% by weight, intrinsic viscosity 0.55 dl / g, A
A prepolymer of V18eq / ton was obtained. Then, in the same manner as in Example 1, solid phase polymerization was performed at 210 ° C. for 20 hours,
A solid-state polymerization chip was obtained. Table 1 shows the main physical properties of the solid-state polymerization chip. The chip has a Ge amount of 53 p
It was pm and P amount 28 weight ppm.

From this chip, as in Example 1, 1
One volume of heat set bottle was obtained. The physical properties of the bottle are shown in Table-1.
Further, even when the continuous operation was performed as in Example 1, the mold was not contaminated. Furthermore, no change was observed in the bottle in the heat filling test carried out in the same manner as in Example 1.

[0046]

[Comparative Example 1] The same operation as in Example 1 was carried out except that 1,4-cyclohexanedimethanol was not added, and the CT amount was 1.01% by weight, the intrinsic viscosity was 0.55 dl / g and AV24.
eq / ton, Ge amount 43 weight ppm, P amount 24 weight p
A pm prepolymer was obtained. Then, in the same manner as in Example 1, solid phase polymerization was carried out at 210 ° C. for 20 hours to obtain a solid phase polymerization chip. Table 1 shows the physical properties of the solid-state polymerization chip. The solid-state polymerized chip had a Ge content of 43 weight ppm and a P content of 24 weight ppm.

The physical properties of an 11-volume thermosetting bottle obtained from this chip in the same manner as in Example 1 are shown in Table 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.

[0048]

Comparative Example 2 The prepolymer obtained in Comparative Example 1 was solid-state polymerized at 210 ° C. for 30 hours in the same manner as in Example 1,
A solid-state polymerization chip was obtained. The physical properties of the solid-state polymerization chip are shown in Table-
Shown in 1. Further, the solid-state polymerization chip has a Ge amount of 43 weight p.
It was pm and P amount 24 weight ppm.

Table 1 shows the physical properties of a 1 liter capacity heat-fixing bottle obtained by the same manner as in the Example, using the solid-state polymerization chip. Also,
The same hot-filling test results as in Example 1 were good for the bottle, but a thin white film-like deposit was observed when the mold after molding was observed as a continuous molding test.

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

[0051]

Comparative Example 3 The holding time after feeding the raw material slurry was set to 3
The reaction was performed in the same manner as in Example 1 except that the time was shortened to 0 minutes,
CT amount 0.94% by weight, intrinsic viscosity 0.56 dl / g, A
V33eq / ton, Ge amount 44 weight ppm, P amount 23
A weight ppm of prepolymer was obtained. Then, in the same manner as in Example 1, solid phase polymerization was carried out at 210 ° C. for 20 hours to obtain a solid phase polymerization chip. Table 1 shows the main physical properties of the solid-state polymerization chip. The solid-state polymerized chip has a Ge amount of 44 weight pp.
The amount of m and P was 23 ppm by weight. Next, from this chip, in the same manner as in Example 1, a heat-fixing bottle having a capacity of 1 l was obtained.
The physical properties of the bottle are shown in Table-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.

[0052]

Comparative Example 4 The same operation as in Example 1 was carried out except that 0.35 kg of diethylene glycol was added to the prepared slurry,
CT amount 0.83% by weight, intrinsic viscosity 0.58 dl / g, A
V23eq / ton, Ge amount 44 weight ppm, P amount 24
A weight ppm of prepolymer was obtained. Then, in the same manner as in Example 1, solid phase polymerization was performed at 210 ° C. for 20 hours to obtain a solid phase polymerization chip. Table 1 shows the main physical properties of the solid-state polymerization chip. The solid-state polymerized chip has a Ge amount of 44 weight pp.
The amount of m and P was 24 ppm by weight.

Table 1 shows the physical properties of an 11-volume thermosetting 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 leakage of liquid from the spout were observed.

[0054]

Comparative Example 5 The same operation as in Example 1 was carried out except that 0.8 kg of 1,4-cyclohexanedimethanol (cis / trans = 30/70) and 5.57 kg of ethylene glycol were used, and the CT amount was 0.80. % By weight, intrinsic viscosity 0.54 dl
/ G, AV22eq / ton, Ge amount 43 weight ppm,
A prepolymer having a P content of 24 ppm by weight was obtained.

Then, in the same manner as in Example 1, 210 ° C.
Solid-state polymerization was carried out for 20 hours to obtain a solid-state polymerization chip. Table 1 shows the main physical properties of the solid-state polymerization chip. Further, the solid-state polymerized chip has a Ge amount of 43 weight ppm and a P amount of 24 weight p.
It was pm. In addition, in the case of this example only, as the oligomers, in addition to the cyclic trimer, cyclohexanedimethano
Several hundred ppm of the cyclic dimer based on the phenol was observed.

From this chip, the same operation as in Example 1 was performed,
11 volumes of heat set bottles were produced. The physical properties of the bottle are shown in Table-1. Further, in the same continuous molding test as in Example 1, slight contamination of the mold was observed, and when a heat filling test was carried out, the entire bottle was deformed and a small amount of liquid leaked from the spout part was observed. .

[0057]

[Table 1]

[0058]

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 copolymerized polyester 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 which require heat resistance.

Front page continuation (51) Int.Cl. ⁷ Identification code FI C08G 63/80 C08G 63/80 B29K 67:00 B29K 67:00 B29L 22:00 B29L 22:00 (72) Inventor Takuji Hirahara Yokohama City, Kanagawa Prefecture 1000 Kamoshida-cho, Midori-ku, Mitsubishi Kasei Co., Ltd. Research Institute (72) Inventor Osamu Kishiro 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Mitsubishi Kasei Co., Ltd. (56) Reference JP-A-3-72524 ( JP, A)

Claims (4)

(57) [Claims] 1. A copolymerized polyester containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a main component as a diol component, wherein (1) cyclohexanedimethanol is 0.5 to 3.5 mol% as the diol component, and diethylene glycol is used. Is 1.
0 to 2.5 mol%, (2) intrinsic viscosity of 0.60 to 1.50 dl / g, (3) terminal carboxyl group concentration of 18 eq / ton or less, (4) cyclic trimer content of 0 A copolymerized polyester having a content of 0.35% by weight or less. 2. A copolymerized polyester containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component as a main component, wherein (1) cyclohexanedimethanol is 0.5 to 3.5 mol% as a diol component, and diethylene glycol is used. Is 1.
0 to 2.5 mol%, (2) intrinsic viscosity 0.50 to 0.70 dl / g, (3) terminal carboxyl group concentration 15 to 30 eq / t
The copolymerized polyester according to claim 1, which is produced by solid-state polymerization of a prepolymer that is on. 3. A hollow container made of a copolyester, which is obtained by subjecting the copolyester according to claim 1 to a preform by injection molding or extrusion molding and then biaxially stretch blow molding. 4. A sheet material obtained by injection molding or extrusion molding of the copolyester according to claim 1,
A stretched film made of Copolymer 4 polyester stretched in at least one direction.