JP3331719B2 - Copolyester for direct blow bottle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a copolymerized polyester useful for a direct blow bottle. Specifically, the molded bottle is excellent in transparency, mechanical strength, heat resistance, low-temperature moldability and drawdown resistance during bottle molding, and the oligomer content in the copolyester is small, The present invention relates to a copolymerized polyester useful as a raw material for a direct blow bottle having such properties that the amount of oligomer by-products is small and that contamination of a mold and the like is small due to a small amount of oligomer by-products.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter, referred to as "polyethylene terephthalate")
It is called "PET". ) Is excellent in mechanical strength, chemical stability, transparency, hygiene, etc., and is lightweight and inexpensive, so it is widely used as a packaging material for various sheets and containers, especially carbonated beverages and fruit juices The growth of containers for beverages, liquid seasonings, edible oils, sake, and wine is remarkable.

[0003] In the case of such a PET, for example, in the case of a bottle, a preform for a hollow molded article is molded by an injection molding machine, and the preform is stretch-blown in a mold having a predetermined shape. In addition, in the case of an inner solution that requires heat filling such as a fruit juice beverage, it is general that the solution is heat-fixed in a blow mold or a separately provided mold and then molded into a bottle. is there.

[0004] In recent years, because of the safety and hygiene properties and easy incineration of PET resins, and the high possibility of recycling, replacement of polyvinyl chloride (hereinafter referred to as "PVC") and other purposes have been proposed. The use of bottles made by direct blow molding is increasing. However, in the conventional PET used for molding, the amount of the cyclic trimer containing oligomer as a main component is usually 1 in prepolymer after melt polymerization.
Usually, 0.5 to 1% by weight is contained even in a solid-state polymerized polymer, and these oligomers adhere to and contaminate equipment such as a mold during molding. The contamination of the mold and the like causes the surface roughness and whitening of the molded product. Therefore, it is necessary to clean the mold and the like as frequently as possible.

[0005] Therefore, attempts have been made to lower the oligomers by extending the solid-phase polymerization time or increasing the amount of the catalyst, but the reduction of oligomers by such a method is limited, and economical. Is not a typical way. On the other hand, copolyesters having properties similar to PET, such as copolyesters using terephthalic acid and isophthalic acid as dicarboxylic acid components, and copolyesters using ethylene glycol and diethylene glycol or cyclohexanedimethanol as diol components. Many are also known. However, copolyesters in which the amount of oligomers is reduced to a certain degree or more and which have properties equivalent to or higher than PET for direct blow have not been specifically known.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the content of oligomers and the amount of by-products of oligomers during molding, so that molds and the like are less likely to be contaminated at the time of molding, and solidified as compared with PET. High productivity due to high polymerization rate and low oligomer reduction rate during phase polymerization, and provide a direct blow bottle with superior performance such as transparency and low-temperature drop strength compared to other copolymerized PET. To provide a copolymerized polyester.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, have a specific physical property in which a certain proportion of cyclohexane dimethanol and diethylene glycol are contained in the constituents of PET. The present inventors have found that the copolyester is a copolyester suitable for direct blow bottles, and have 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 diol component, and (1) 0.5 to 10 mol of cyclohexane dimethanol as a diol component. % And diethylene glycol 1 to
(2) the content of germanium atoms is 2
0 to 60 ppm, (3) the terminal carboxyl group is 18 equivalents / ton or less, (4) the cyclic trimer is 0.40% by weight or less,
(5) intrinsic viscosity 0.65 to 1.50 dl / g, (6)
The crystallization temperature (Tc ₁ ) and the crystallization exotherm (ΔHc) are 170 ≦ Tc ₁ ≦ 195 ° C. and 0.5 ≦ ΔHc ≦
15 mj / mg, which is a copolyester for a direct blow bottle, and a copolyester bottle obtained by direct blowing the copolyester.

Hereinafter, the present invention will be described in detail. In the copolymerized polyester of the present invention, for terephthalic acid and ethylene glycol as main components, known raw materials used in PET may be used. Further, the cyclohexanedimethanol raw material of the present invention includes 1,2--1,3- and 1,1-
4-cyclohexanedimethanol may be mentioned, and the cis-trans ratio may be a mixture of any ratio. Of these, usually 1,4-cyclohexane dimethanol,
Those having a cis / trans ratio of (20 to 80) / (80 to 20) are particularly preferably used.

Further, diethylene glycol (hereinafter referred to as "D
EG ". In the case of), ethylene glycol is partially produced as a by-product during the polymerization reaction. Therefore, in addition to using a predetermined amount of DEG or its ester-forming derivative as a raw material for polymerization, reaction conditions, additives, and the like are appropriately selected. Only with this, the content of the DEG component can be controlled. In particular, in the case of the copolymerized polyester of the present invention, the melt polymerization temperature can be lowered by the effect of adding cyclohexanedimethanol, and it is easy to keep the content of the DEG component low. Examples of the additives include tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine; and quaternary hydroxides such as tetraethylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide. A small amount of a basic compound such as ammonium and lithium carbonate, sodium carbonate, potassium carbonate, and sodium acetate can be added to suppress generation of DEG. On the other hand, if a small amount of an inorganic acid such as sulfuric acid is added to the polymerization raw material, DEG
Can be promoted and the content can be increased. These additives for controlling the amount of DEG produced are used, if necessary, usually in the range of 0.001 to 10% by weight, preferably 0.005 to 1% by weight of the whole polymerization raw materials.

In the copolymerized polyester of the present invention, the ratio of cyclohexanedimethanol in all diol components is 0.1%.
5 to 10 mol%, preferably 1 to 7 mol%, more preferably 2 to 4.5 mol%, and the proportion of DEG in all diol components is 1 to 4 mol%, preferably 1 to 4 mol%. It is in the range of 0.5 to 3.5 mol%, more preferably 2 to 3.5 mol%.

When each of the above copolymer components is less than the above range, the oligomer reduction rate in the solid phase polymerization step in producing the copolymerized polyester of the present invention is low,
Further, the effect of reducing oligomers adhering to the mold during molding is small, and no superiority over conventional PET is recognized. On the other hand, if it exceeds the above range, the crystallinity is remarkably reduced, causing a problem of fusion at the time of solid-phase polymerization and the solid-state polymerization temperature cannot be increased, resulting in a decrease in productivity.

Particularly, in direct blow molding, if the amount of cyclohexane dimethanol is too small, low-temperature molding cannot be performed, so that draw-down resistance is poor, and the parison length required for bottle molding cannot be obtained. In the above raw material composition, a copolymer polyester suitable for direct blow molding and having a cyclic trimer as a main component of the oligomer of 0.40% by weight or less can be easily obtained.

The content of germanium atoms in the copolymerized polyester of the present invention is 20 to 60 ppm by weight, preferably 25 to 55 ppm by weight. If the content of germanium atoms is less than the above range, it is not practical in the production of the copolymerized polyester because the oligomer is slowly reduced and the solid-state polymerization rate is low. On the other hand, if it exceeds the above range, the amount of by-products of the oligomer at the time of molding is increased, so that the effect of improving the stain on the mold is not sufficient. The germanium atom is derived from a germanium compound used as a polymerization catalyst for the copolymerized polyester of the present invention and incorporated into the polymer.

[0015] The terminal carboxyl group of the copolymerized polyester of the present invention is 18 equivalents / ton or less, preferably 15 equivalents / ton or less. If the concentration of the terminal carboxyl group exceeds the above range, the effect of reducing oligomers adhering to a mold or the like at the time of molding is small, and the moisture resistance, heat stability, and the like are undesirably reduced. The content of the cyclic trimer of the copolymerized polyester of the present invention is 0.40% by weight or less, preferably 0.35% by weight or less. If the cyclic trimer exceeds the above range, the effect of reducing oligomers adhering to a mold or the like during molding is small, which is not preferable.

The intrinsic viscosity of the copolymerized polyester of the present invention is phenol / tetrachloroethane (weight ratio 1/1).
0.65 to 1.50 as measured at 30 ° C. in a mixed solvent of
dl / g, preferably 0.75 to 1.35 dl / g, and more preferably 0.90 to 1.25 dl / g. If it is less than 0.65 dl / g, the melt viscosity is not sufficiently high, so that when the obtained copolyester is subjected to direct blow molding, drawdown resistance is poor and a normal molded product cannot be obtained. In addition, when it exceeds 1.50 dl / g,
Because the solid phase polymerization time is too long, the productivity becomes worse,
Not preferred.

The copolymerized polyester of the present invention needs to have a crystallization temperature (Tc ₁ ) and a crystallization exotherm (ΔHc) in the specific ranges determined by the following measurement methods. That is, using a differential scanning calorimeter “DSC220C” manufactured by Seiko Denshi Co., Ltd., a sample amount of 8 to 11 mg was measured, and the temperature was raised from room temperature to 285 ° C. at a rate of 20 ° C./min, and further increased by 285 ° C. After the sample was melted and stored at 3 ° C. for 3 minutes, the sample was taken out, put into liquid nitrogen, rapidly cooled, taken out and air-dried, and then heated again from room temperature to 285 ° C. at a heating rate of 20 ° C./min. The peak top temperature of the crystallization peak (so-called low-temperature crystallization temperature) is defined as the crystallization temperature (Tc ₁ ), and the calorific value determined from the peak area is defined as the crystallization calorific value (ΔHc).

The Tc ₁ and ΔHc of the copolymerized polyester of the present invention are 170 ≦ Tc ₁ ≦ 195 ° C., respectively.
0.5 ≦ ΔHc ≦ 15 mj / mg. Tc ₁ is 17
If the temperature is 0 ° C. or less or ΔHc is 15 mj / mg or more, the extruded parison tends to be whitened during direct blow molding due to a high crystallization rate, which is not preferable.
Further, the copolymerized polyester of the present invention can be obtained by subjecting a polymer (hereinafter, referred to as a prepolymer) obtained by melt polymerization, which is a known technique, to solid phase polymerization.
Tc ₁ and ΔHc of this prepolymer were 160 ≦ Tc ₁ ≦ 185 ° C. and 10 ≦ ΔHc ≦ 25 mj /
mg. Tc ₁ is 160 ° C. or less, or Δ
When Hc is 25 mj / mg or more, Tc _{1 of the} copolyester is 17 even if the intrinsic viscosity is increased by solid-phase polymerization.
It is 0 ° C. or less, or ΔHc tends to be 15 mj / mg or more, and it is difficult to form the copolymerized polyester of the present invention. When Tc ₁ is 185 ° C. or more or ΔHc is 10 mj / mg or less, the crystallization rate is low, so that fusion is likely to occur at the crystallization stage in the solid phase polymerization step, and handling is difficult. . When a prepolymer having Tc ₁ of 185 ° C. or less and ΔHc of 10 mj / mg or more is subjected to solid-state polymerization to form the copolymerized polyester of the present invention, Tc ₁ of 195 ° C. or less and ΔHc of 0.1 m. 5
mj / mg or more.

The above-mentioned copolymerized polyester of the present invention comprises P
The ET is produced by a conventionally known method by performing melt polymerization followed by solid phase polymerization. Hereinafter, the manufacturing method will be described in detail. As a melt polymerization method, for example, after performing an esterification reaction directly under pressure using terephthalic acid, ethylene glycol and cyclohexane dimethanol, diethylene glycol is added as necessary, and the temperature is further increased in the presence of a catalyst. In addition, there is a method in which the pressure is gradually reduced to cause a polycondensation reaction. Or,
An ester derivative of terephthalic acid, for example, dimethyl terephthalate, and a transesterification reaction in the presence of a catalyst using ethylene glycol and cyclohexane dimethanol, and then reacting the obtained reaction product with the above-described direct esterification reaction product Similarly, there is a method of performing a polycondensation reaction. In addition, cyclohexanedimethanol can be optionally added at the beginning of the polycondensation reaction.

Such a polycondensation reaction may be performed in one stage or may be performed in a plurality of stages. When the reaction is carried out in a plurality of stages, the polycondensation reaction conditions are such that the reaction temperature of the first stage polycondensation is usually 250 to 290 ° C, preferably 260 to 280 ° C.
At a pressure of usually 500 to 20 Torr, preferably 2 torr.
And the temperature of the polycondensation reaction in the final stage is usually 265 to 300 ° C., preferably 270 to 2 ° C.
The temperature is 95 ° 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 stages,
The polycondensation reaction conditions of the first stage and the second stage are in the above ranges, respectively. When the polycondensation reaction is carried out in three or more stages, the polycondensation reaction from the second stage to one stage before the final stage is performed. Is a condition between the above-mentioned first-stage reaction condition and the last-stage reaction condition. For example, when the polycondensation reaction is performed in three stages, the reaction temperature of the second stage polycondensation reaction is usually 260 to 295 ° C, preferably 270 ° C.
To 285 ° C., and the pressure is usually in the range of 50 to 2 Torr, preferably 40 to 4 Torr. In each of these polycondensation reaction steps, the intrinsic viscosity reached is not particularly limited, but it is preferable that the degree of increase in the intrinsic viscosity in each stage is smoothly distributed, and furthermore, the final stage polycondensation reactor The intrinsic viscosity of the copolymerized polyester prepolymer obtained from the above is usually 0.45 to 0.80 dl / g, preferably 0.50 to 0.75 dl / g.

The copolyester prepolymer thus obtained is usually melt-extruded into strands,
It is cut into granular chips by a cutter. Such a granular prepolymer chip usually has a size of 2 to 5.5 m.
m, preferably 2.2 to 4.5 mm. In these direct esterification, transesterification, and polycondensation reactions, it is preferable to use an esterification catalyst, a transesterification catalyst, a polycondensation catalyst, or the like.

Examples of the transesterification catalyst include known compounds such as calcium, manganese, magnesium, zinc, titanium, sodium and lithium compounds.
Although more than one kind can be used, a manganese, magnesium, or titanium compound is particularly preferable from the viewpoint of transparency. As a polymerization catalyst, a germanium compound is used from the viewpoint of colorless transparency. Specific examples include germanium dioxide, germanium tetrachloride and the like, and fine powder of germanium dioxide, an aqueous solution and a germanium dioxide solution such as an ethylene glycol solution are particularly preferably used. In addition, one or more other polymerization catalysts such as antimony, titanium, and cobalt compounds may be used in combination without departing from the gist of the present invention. It is necessary to adjust the addition amount of the germanium compound so that the content of germanium atoms in the final copolymerized polyester is 20 to 60 ppm.

In the present invention, other known stabilizers may be added. For example, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate,
Phosphates such as trioctyl phosphate, triphenyl phosphate and tricresyl phosphate Phosphite such as triphenyl phosphite, trisdodecyl phosphite and trisnonyl phenyl phosphite, methyl acid phosphate, isopropyl acid phosphate, butyl Acid phosphate, dibutyl phosphate, monobutyl phosphate,
Acidic phosphates such as dioctyl phosphate and phosphorus compounds such as phosphoric acid, phosphorous acid and polyphosphoric acid are used. The stabilizer is used in an amount of usually 0.001 to 0.1% by weight, preferably 0.002 to 0.02% by weight, based on the weight of phosphorus atoms in the stabilizer.

Further, as long as the constitutional requirements of the present invention are not deviated, a small amount of a dicarboxylic acid component other than terephthalic acid and a diol component other than ethylene glycol, diethylene glycol and cyclohexanedimethanol may be contained. It may contain small amounts of components. These dicarboxylic acid components include phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenylsulfonedicarboxylic acid, 4,4′-biphenyldicarboxylic acid and structural isomers thereof, and aliphatic acids such as malonic acid, succinic acid and adipic acid. Examples of the diol component include aliphatic diols such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol, and neopentyl glycol. Examples thereof include aromatic dihydroxy compounds such as bisphenol A and bisphenol S. Examples of the oxyacid or a derivative thereof include p-hydroxybenzoic acid, p-hydroxybenzoic acid and p-hydroxybenzoic acid.
-Hydroxybenzoic acid esters, glycolic acid and the like.

Further, a small amount of a monofunctional compound or a trifunctional or higher polyfunctional compound may be contained without departing from the constitutional requirements of the present invention. Examples of the monofunctional compound include benzoic acid, alkylphenylcarboxylic acids such as methylbenzoic acid and t-butylbenzoic acid, allylphenylcarboxylic acids such as benzoylbenzoic acid, and lower alkyl esters of these monofunctional carboxylic acids, and monofunctional compounds thereof. Nuclear substituents of the compound are mentioned. Examples of the trifunctional or higher polyfunctional compound include trimellitic acid, trimesic acid, and their structural isomers, pyromellitic acid and its structural isomers, or anhydrides and core-substituted products of these polyfunctional compounds, Trimethylolethane, trimethylolpropane,
Examples include polyhydroxy compounds such as glycerin and pentaerythritol, and glycidyl ethers of aromatic dihydroxy compounds, such as polyfunctional compounds such as bisphenol A diglycidyl ether. These monofunctional compounds and trifunctional or higher polyfunctional compounds are generally used in an amount of 5 mol% or less, preferably 0.001 to 2.0 mol%, based on the repeating units constituting the polymer.
In particular, by using a polyfunctional compound having three or more functions, the drawdown property at the time of direct blow molding can be improved.

Next, in order to obtain the copolymerized polyester of the present invention, it is necessary to further subject the granular copolymerized polyester prepolymer chips obtained by melt polymerization as described above to a solid phase polymerization treatment. By selecting the conditions for the solid phase polymerization, it is possible to obtain a copolymerized polyester having the above-mentioned physical properties specified in the present invention. The copolyester chips supplied to the solid phase polymerization may be preliminarily crystallized by heating to a temperature lower than the temperature at which the solid phase polymerization is performed, and then supplied during the solid phase polymerization step. In such a pre-crystallization step, the copolyester chips are dried in a dry state, usually at 120 to 200 ° C, preferably 130 to 180 ° C.
C. for 1 minute to 4 hours, or by heating the chip under a steam or an inert gas atmosphere containing steam, usually at a temperature of 120 to 200.degree. C. for 1 minute or more. .

The solid-state polymerization step in which the above-mentioned granular copolyester chips are supplied comprises at least one stage.
The polymerization temperature is 190 to 230 ° C, preferably 195 to 23
The reaction is carried out at 5 ° C. and at an arbitrary pressure of 1 kg / cm ² G to 0.01 Torr, under a flow of an inert gas such as nitrogen, argon, carbon dioxide or the like, or in an atmosphere without flow. The polymerization time reaches desired physical properties in a shorter time as the temperature is higher, but is usually 1 to 50 hours, preferably 5 to 30 hours, more preferably 10 to 25 hours.

The copolymer polyester of the present invention can be obtained by appropriately selecting the conditions for the above solid phase polymerization treatment. The thus obtained copolymerized polyester of the present invention is preferably used in producing a bottle (hollow container) by direct blow molding.
The direct blow method is a method in which a parison (or preform) formed by an extruder or an injection molding machine is still soft and completes blow molding before losing plasticity. As the molding machine, an apparatus conventionally used for blow molding of polystyrene or polyvinyl chloride can be used as it is. In this case, the molding temperature can be set at a temperature of each part of the cylinder or the nozzle in the range of usually 250 to 280 ° C., 5 to 20 ° C. lower than that of the general PET for bottles, and it is easy to suppress the thermal deterioration to a low level. Furthermore, it is easy to keep the amounts of by-product oligomers and acetaldehyde low.

[0030]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. In addition, various measurement methods and evaluation methods used in this example are described below. Incidentally, a method of measuring the intrinsic viscosity, Tc ₁ and ΔHc measuring method of DSC are as defined above.

(1) Amount of cyclohexane dimethanol and amount of diethylene glycol The copolymerized polyester pulverized and pulverized by a conventional method is heated and alkali-decomposed with a methanol solution of potassium hydroxide, and the produced diol component is neutralized and quantified by gas chromatography. did. (2) Content of germanium atom The copolyester was decomposed and ashed in the presence of sulfuric acid according to a conventional method, and the content of the copolyester was adjusted to a constant volume with distilled water, and quantified by emission spectroscopy.

(3) Content of antimony atom It was quantified by emission spectroscopy in the same manner as in the analysis of germanium atom content. (4) Terminal Carboxyl Group Concentration 100 mg of the pulverized and finely divided copolymerized polyester was dissolved in 5 ml of benzyl alcohol by heating, and 5 ml of chloroform was added thereto. The mixture was diluted with phenol red as an indicator using 0.1 N sodium hydroxide / benzyl. It was titrated with an alcohol solution and quantified.

(5) Content of cyclic trimer 200 mg of the copolymerized polyester was added to chloroform / 1,
It was dissolved in 2 ml of a 1,1,3,3,3-hexafluoro-2-propanol mixed solution (volume ratio: 3/2), and further diluted with 20 ml of chloroform. 10 ml of methanol was added thereto to reprecipitate the polymer component, and a filtrate was obtained after filtration. The filtrate was evaporated to dryness using an evaporator, and 25 ml of dimethylformamide was added to the residue to dissolve the solution, and the solution was quantified using a liquid chromatograph.

(6) Evaluation of Direct Blow Molding Using a direct blow molding machine manufactured by Nippon Steel Works, “electric small-sized blow molding machine JEB-7 / P50 / WS60S”, at a predetermined temperature condition, at an extrusion speed of about 15 kg / hour. , 13
In a molding cycle of about seconds, a bottle having a capacity of 700 ml was subjected to direct blow molding. The mold temperature was controlled at 15 ° C. The molding temperature in the examples indicates the set temperature of the heater of the adapter part of the molding machine. All of the polymers for evaluation were sufficiently dried by a conventional method and provided for molding.

As the molding evaluation items, the blowable parison length, which is an index of the drawdown resistance, the visual observation of the molded bottle, and the stain of the mold during molding for a total of 50 hours were evaluated. The drawdown is a phenomenon in which the extruded parison (or preform) hangs down by its own weight in blow molding.

Example 1 318 kg (1.56 kmol) of bis (2
A slurry prepared from 259 kg (1.56 kmole) of terephthalic acid and 116 kg (1.87 kmole) of ethylene glycol in an esterification tank in which a PET oligomer mainly composed of (-hydroxyethyl) terephthalate was melted and maintained at about 250 ° C. with stirring. Was sequentially supplied over 6 hours.
After the completion of the supply, the esterification reaction was further allowed to proceed for 30 minutes, and then half the amount was transferred to a polycondensation tank, and 1,4-cyclohexanedimethanol (cis / trans ratio = 30/70) was stirred.
8.74 kg (0.06 kmol), 2.43 kg (0.02 kmol) of diethylene glycol, 45 g of phosphoric acid
(To 150 ppm with respect to the polymer) and 36 g of germanium dioxide (to 120 ppm with respect to the polymer) were sequentially added as ethylene glycol solutions having appropriate concentrations. Subsequently, the temperature was gradually increased from 250 ° C. to 280 ° C., and the pressure was gradually reduced from normal pressure, and the pressure was maintained at 0.5 Torr. After the reaction was carried out for 3 hours and 30 minutes, the produced prepolymer was drawn out in a strand form from a discharge port provided at the bottom of the polycondensation tank, cooled with water, and then cut into chips. Table 1 shows the analysis results of the prepolymer chip.

Next, 40 kg of the prepolymer chip was
The mixture was charged into a double-cone type rotary solid-state polymerization apparatus having a capacity of 100 liters, and the atmosphere was replaced with nitrogen under reduced pressure three times. + 120 ° C x 5 hours + 160 ° C x
Vacuum solid-phase polymerization was performed for 6 hours + 215 ° C. × 44 hours (each time including a temperature rise time to a set temperature of 1 hour), and after cooling, the pressure was restored with nitrogen to obtain a solid-phase polymerized polymer. At this time, there was no fusion of the polymer in the solid-state polymerization apparatus. Assuming that the time from when the temperature reached 190 ° C. to the start of cooling is the solid phase polymerization time, the solid phase polymerization time was 41 hours, and the temperature in the main solid phase polymerization region was 207 ° C. Table 2 shows the analysis results of the obtained solid-phase polymerized polymer.

When the molding was evaluated using the solid-state polymerized polymer under the standard molding conditions at the above-mentioned standard set temperature, the parison length at which blow was possible was 30 cm, and the result of visual observation of the molded bottle was colorless and transparent. Good, substantially no mold stains were observed during molding for a total of 50 hours. In addition,
In Tables 1 and 2, IV is the limiting viscosity, CHDM is the amount of 1,4-cyclohexanedimethanol component, DEG is
Is the amount of diethylene glycol component, CT is the amount of cyclic trimer, AV is the amount of terminal carboxyl group, GeO ₂ is the amount of germanium dioxide, Sb ₂ O ₃ is the amount of antimony trioxide, and Ge is the amount of germanium atom. , Sb indicate the amount of antimony atoms.

Example 2 and Comparative Examples 1 to 3 Example 1 was repeated except that the raw materials shown in Table 1 were charged.
Each polymer was produced in the same manner as described above. Table 1 shows the quality of the prepolymer, Table 2 shows the quality of the solid-phase polymerized polymer, and Table
3 shows the results of evaluation by direct blow molding.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

According to the present invention, the copolymerized polyester prepolymer of the present invention can be efficiently produced with high productivity without problems such as fusion during solid phase polymerization. Further, the copolymerized polyester of the present invention can be molded at a lower temperature than ordinary PET for bottles and has high drawdown resistance, so that direct blow molding can be easily performed. In addition, even if continuous molding is performed for a long period of time, since the mold is less contaminated, the frequency of mold cleaning can be reduced, and the productivity is high. The hollow container made of the copolymerized polyester of the present invention is colorless and transparent, has an excellent appearance, and has high commercial value. In view of the above, the copolymerized polyester of the present invention and the hollow container made thereof have high industrial value.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (3)

(57) [Claims] 1. A terephthalic acid as a dicarboxylic acid component,
A copolymerized polyester containing ethylene glycol as a main component as a diol component, (1) containing 0.5 to 10 mol% of cyclohexane dimethanol and 1 to 4 mol% of diethylene glycol as a diol component, and (2) containing a germanium atom. (3) a terminal carboxyl group of 18 equivalents / ton or less, (4) a cyclic trimer of 0.40% by weight or less, (5) an intrinsic viscosity of 0.65 to 1.50 dl / g, (6) Crystallization temperature (Tc ₁ ) and crystallization heat value (ΔH)
c) is 170 ≦ Tc ₁ ≦ 195 ° C. and 0.5 ≦ Δ, respectively.
A copolymer for direct blow bottles, wherein Hc ≦ 15 mj / mg. 2. A crystallization temperature (Tc ₁ ) and a crystallization exotherm (ΔHc) of 160 ≦ Tc ₁ ≦ 185 ° C., respectively.
2. The copolymerized polyester for a direct blow bottle according to claim 1, wherein a prepolymer obtained by melt polymerization satisfying 0 ≦ ΔHc ≦ 25 mj / mg is solid-phase polymerized. 3. A terephthalic acid as a dicarboxylic acid component,
A copolymerized polyester containing ethylene glycol as a main component as a diol component, (1) containing 0.5 to 10 mol% of cyclohexane dimethanol and 1 to 4 mol% of diethylene glycol as a diol component, and (2) containing a germanium atom. (3) a terminal carboxyl group of 18 equivalents / ton or less, (4) a cyclic trimer of 0.40% by weight or less, (5) an intrinsic viscosity of 0.65 to 1.50 dl / g, (6) Crystallization temperature (Tc ₁ ) and crystallization heat value (ΔH)
c) is 170 ≦ Tc ₁ ≦ 195 ° C. and 0.5 ≦ Δ, respectively.
A bottle obtained by directly blowing a copolymerized polyester satisfying Hc ≦ 15 mj / mg.