JPH0789525A - Polyester bottle and its manufacture - Google Patents

Abstract

PURPOSE:To provide a bottle with an excellent heat resistance, for which the adsorption of a taste component or fragrance component, etc., is reduced by keeping the body part of the bottle under a mean crystallinity of a specified range for an oriented bottle made of polyester. CONSTITUTION:A pre-form is obtained by forming a copolymer polyester by an injection forming machine, and the pre-form is heated by an infrared ray heater in such a manner that the central surface temperature of the pre-form body 4 may become 115 deg., and orientation-blown by a forming machine, and thus, a bottle 1 is formed. In addition, this bottle is heat-set for not less than 3 seconds at a die temperature of 110-200 deg., and the mean crystallinity of the bottle body part 4 is made to be 32-70%. Then, the heat-set bottle 1 is cooled from the inside and outside, and taken out from the die. By this method, since the crystallinity of the bottle body part 4 is large, a bottle with an excellent non-adsorption property and heat resistance can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester bottle and a method for producing the same, and more particularly to a polyester bottle having excellent non-adsorptive properties and heat resistance and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Conventionally, various plastics such as polyethylene terephthalate have been used as a material for beverage bottles such as juice, natural water, and various kinds of tea. Plastic bottles are generally thrown away, but in recent years, energy saving and resource saving have been demanded, and such plastic bottles are also required to be reused.

By the way, when a plastic bottle is reused, a bottle that has undergone a washing process and a sterilization process for removing foreign substances adhering to the bottle or adsorbed substances such as taste components and aroma components adsorbed on the bottle may be used. , The contents are sent to the filling process. However, it is difficult to completely remove the adsorbate adsorbed on the bottle in this washing step. The adsorbate adsorbed on the bottle, after the content is filled, moves to the content and deteriorates the aroma and taste of the content, so a bottle for repeated use is a bottle with excellent adsorption properties, that is, a taste component, an aroma. It must be a bottle that absorbs a small amount of ingredients.

The bottle is heat-sterilized after washing,
Since it is filled with a high temperature liquid that has been subjected to heat sterilization treatment, heat resistance is also required. As a result of intensive studies in view of the above situation, the present inventors have made a bottle made of a specific polyester and having a high degree of crystallinity of the body, which has less adsorption of taste components, aroma components, etc., and is heat resistant. They have found that they are excellent and have completed the present invention.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art, and provides a polyester bottle excellent in non-adsorption and heat resistance, and a method for producing the same. It is an object.

[0006]

SUMMARY OF THE INVENTION A polyester bottle according to the present invention is
A stretched bottle formed of polyester, characterized in that the average crystallinity of the bottle body is in the range of 32 to 70%.

In the present invention, the polyester is a stretched bottle formed of one kind of polyester selected from the group consisting of polyethylene naphthalate, the following copolyester (A) and the following polyester resin composition, and the bottle body The average crystallinity of is preferably in the range of 32 to 70%.

Copolymerized polyester (A): (a) 80-100 mol% of terephthalic acid unit, 2,6-
Naphthalenedicarboxylic acid or isophthalic acid component unit 0
A dicarboxylic acid constitutional unit consisting of ˜20 mol%, (b)
80 to 100 mol% of ethylene glycol component unit and glycol component unit 2 other than ethylene glycol component unit 2
Copolymerized polyester composed of 0 to 0 mol% of dihydroxy compound constitutional unit Polyester resin composition: (I) Polyethylene terephthalate 85 to 99% by weight
And (II) (a) isophthalic acid component unit 20 to 100 mol%
And a dicarboxylic acid constitutional unit comprising 80 to 0 mol% of a terephthalic acid component unit, (b) a dihydroxyethoxyresorcinol component unit of 5 to 90 mol%, and an ethylene glycol component unit of 95 to 10 mol% Copolymerized polyester (B) 15 to 15 parts each of which is a polyfunctional hydroxy compound structural unit having at least 3 hydroxy groups 1% by weight
A composition comprising:

In the polyester bottle of the present invention, the amount of methanol adsorbed on the body of the bottle is preferably 1500 ppm or less, and the amount of paraxylene adsorbed on the body of the bottle is preferably 300 ppm or less. It is desirable that the stretching index defined as above is 130 cm or more.

[0010]

[Equation 3]

In the method for producing a polyester bottle according to the present invention, a preform made of polyester is heated and stretch-blown in a mold so that the crystallinity of the bottle body is within the range of 32 to 70%. It is characterized by

In the present invention, the polyester is preferably one selected from the group consisting of polyethylene naphthalate, the above copolymerized polyester (A) and the above polyester resin composition.

In the method for producing a polyester bottle of the present invention, it is desirable to heat set the bottle body blown at the mold temperature of 100 to 250 ° C. It is desirable to stretch and blow so that the stretching index is 130 cm or more.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The polyester bottle and the method for producing the same according to the present invention will be specifically described below.

As the polyester used in the polyester bottle of the present invention, the following polyethylene naphthalate, copolymerized polyester (A) and polyester resin composition are preferable.

[Polyethylene Naphthalate] The polyethylene naphthalate used in the present invention has an ethylene-2,6-naphthalate unit derived from 2,6-naphthalenedicarboxylic acid and ethylene glycol in an amount of 60 mol% or more, preferably 80 mol. %, And more preferably 90 mol% or more, but it is also possible to contain structural units other than ethylene-2,6-naphthalate in an amount of less than 40 mol%.

Examples of constitutional units other than ethylene-2,6-naphthalate include terephthalic acid, isophthalic acid,
2,7-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'- Diphenoxyethanedicarboxylic acid,
Aromatic dicarboxylic acids such as dibromoterephthalic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, and fats such as 1,4-cyclohexanedicarboxylic acid, cyclopropanedicarboxylic acid, and hexahydroterephthalic acid Hydroxycarboxylic acids such as cyclic dicarboxylic acid, glycolic acid, p-hydroxybenzoic acid and p-hydroxyethoxybenzoic acid, and propylene glycol, trimethylene glycol, diethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene Glycol, neopentylene glycol, p-xylene glycol, 1,4-cyclohexanedimethanol, bisphenol A, p, p-diphenoxysulfone, 1,4-bis (β-hydroxyethoxy) benzene, 2,2-bi (P-beta-hydroxyethoxy phenol) propane, polyalkylene glycol, p- phenylene bis (dimethyl siloxane) include structural units derived from glycerin and.

The polyethylene naphthalate used in the present invention contains a small amount of a component unit derived from a polyfunctional compound such as trimesic acid, trimethylolethane, trimethylolpropane, trimethylolmethane and pentaerythritol, for example, 2 mol% or less. May be included in the amount of.

Further, the polyethylene naphthalate used in the present invention contains a small amount of a component unit derived from a monofunctional compound such as benzoylbenzoic acid, diphenylsulfone monocarboxylic acid, stearic acid, methoxypolyethylene glycol and phenoxypolyethylene glycol, for example, 2 mol. It may be contained in an amount of not more than%.

Such polyethylene naphthalate is
It is substantially linear, which is confirmed by the dissolution of the polyethylene naphthalate in o-chlorophenol.

The intrinsic viscosity [η] of polyethylene naphthalate measured in o-chlorophenol at 25 ° C. was 0.2.
~ 1.1 dl / g, preferably 0.3-0.9 dl / g,
Particularly preferably, it is desirable to be in the range of 0.4 to 0.8 dl / g.

The intrinsic viscosity [η] of polyethylene naphthalate is measured by the following method. That is, polyethylene naphthalate is added to o-chlorophenol at 1 g /
Melt at a concentration of 100 ml, measure the solution viscosity at 25 ° C using an Ubbelohde-type capillary viscometer, and then gradually add o-chlorophenol to measure the solution viscosity on the low concentration side to reach 0% concentration. The outside viscosity is searched to find the intrinsic viscosity ([η]).

The temperature rise crystallization temperature (Tc) when the temperature is raised at a rate of 10 ° C./min with a differential scanning calorimeter (DSC) of polyethylene naphthalate is usually 150 ° C. or higher, preferably 160. ~ 230 ° C, more preferably 17
It is preferably in the range of 0 to 220 ° C.

The temperature rise crystallization temperature (Tc) of polyethylene naphthalate is measured by the following method. That is, using a Perkin Elmer DSC-2 type differential scanning calorimeter, a thin sample of about 10 mg collected from the center of a polyethylene naphthalate chip dried at about 140 ° C. under a pressure of about 5 mmHg for about 5 hours or more. Is enclosed in a liquid aluminum pan under a nitrogen atmosphere for measurement. The measurement conditions are as follows: the peak temperature of the exothermic peak detected when the temperature is raised rapidly from room temperature, melted and held at 290 ° C. for 10 minutes, rapidly cooled to room temperature, and then raised at a temperature rising rate of 10 ° C./min. Ask for.

[Copolymerized Polyester (A)] The copolymerized polyester (A) used in the present invention comprises a dicarboxylic acid constituent unit comprising a terephthalic acid component unit and a 2,6-naphthalenedicarboxylic acid or isophthalic acid component unit. , A dihydroxy compound constitutional unit consisting of an ethylene glycol component unit.

The dicarboxylic acid constitutional unit constituting the copolyester (A) has 80 terephthalic acid component units.
To 100 mol%, preferably 85 to 99.5 mol%, more preferably 85 to 97 mol%, and the 2,6-naphthalenedicarboxylic acid or isophthalic acid component unit is 0 to
It is desirable to be present in an amount of 20 mol%, preferably 0.5 to 15 mol%, more preferably 3 to 15 mol%.

In the copolyester (A) used in the present invention, in addition to the terephthalic acid component, 2,6-naphthalenedicarboxylic acid and isophthalic acid components as the dicarboxylic acid constituent units, the resulting copolyester (A Other dicarboxylic acid components may be contained in a range that does not impair the characteristics of 1), for example, in an amount of 1 mol% or less.

Examples of such a dicarboxylic acid component include component units derived from phthalic acid, 2-methylterephthalic acid and the like. Further, in the copolyester (A) used in the present invention, in addition to the ethylene glycol component as the dihydroxy compound constitutional unit, a range not impairing the properties of the copolyester (A) obtained, for example, 1 mol% or less. Other dihydroxy compound components may be contained in the amount of.

Examples of such dihydroxy compound components include 1,3-propanediol, 1,4-butanediol, neopentyl glycol, cyclohexanediol, cyclohexanedimethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, 2,2-bis (4-β-hydroxyethoxyphenyl)
Propane, bis (4-β-hydroxyethoxyphenyl)
Component units derived from dihydroxy compounds having 3 to 15 carbon atoms such as sulfone are included.

The intrinsic viscosity [η] of the copolyester (A) used in the present invention is in the range of 0.5 to 1.5 dl / g, preferably 0.6 to 1.2 dl / g. desirable.

[Polyester Resin Composition] The polyester resin composition used in the present invention contains 85 to 99% by weight of polyethylene terephthalate, preferably 85 to 95% by weight, and 15 to 1% by weight of the copolymerized polyester (B).
It is preferably a composition formed with 15 to 5% by weight. The intrinsic viscosity [η] of such a polyester resin composition is 0.5 to 1.5 dl / g, preferably 0.6 to
It is preferably within the range of 1.2 dl / g.

Polyethylene terephthalate The polyethylene terephthalate used in the present invention is produced by using terephthalic acid and ethylene glycol as raw materials. The polyethylene terephthalate contains 20 mol% or less of other dicarboxylic acids and / or other dihydroxy compounds. May be copolymerized.

Specific examples of the dicarboxylic acid used for copolymerization other than terephthalic acid include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid and diphenoxyethanedicarboxylic acid; adipic acid and sebacine. Examples thereof include aliphatic dicarboxylic acids such as acids, azelaic acid and decanedicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

As dihydroxy compounds used for copolymerization other than ethylene glycol, specifically, aliphatic glycols such as trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol and dodecamethylene glycol; cyclohexane Alicyclic glycols such as dimethanol; bisphenols; hydroquinone, 2,2-
Examples thereof include aromatic diols such as bis (4-β-hydroxyethoxyphenyl) propane.

Such polyethylene terephthalate forms a substantially linear polyester by forming ethylene terephthalate component units alone or by randomly arranging the ethylene terephthalate component units and the dioxyethylene terephthalate component units to form an ester bond. is doing. The fact that the polyethylene terephthalate is substantially linear is confirmed by the fact that the polyethylene terephthalate is dissolved in o-chlorophenol.

In such polyethylene terephthalate, the intrinsic viscosity [η] (value measured in o-chlorophenol at 25 ° C.) is usually 0.6 to 1.5 dl / g, preferably 0.7 to 1.2 dl. / G is desirable. The melting point is usually 210 ° C to 265 ° C, preferably 220 to 26.
It is desirable that the temperature is 0 ° C., and the glass transition temperature is usually 50.
It is desirable to be 120 ° C to 120 ° C, preferably 60 ° C to 100 ° C.

Copolymerized Polyester (B) The copolymerized polyester (B) used in the present invention comprises a dicarboxylic acid constitutional unit, a dihydroxy compound constitutional unit,
It is formed from a polyfunctional hydroxy compound structural unit having at least three hydroxy groups.

The dicarboxylic acid constitutional unit constituting this copolyester (B) has 20 isophthalic acid component units.
~ 100 mol%, preferably 50-98 mol%,
Further, it is desirable that the terephthalic acid component unit is present in an amount of 0 to 80 mol%, preferably 0.5 to 50 mol%.

The dihydroxy compound constitutional unit contains the dihydroxyethoxyresole component unit in an amount of 5 to 90 mol%, preferably 10 to 85 mol%, and the ethylene glycol component unit in an amount of 10 to 95 mol%, preferably 15 mol%. It is desirable to be present in an amount of ˜90 mol%.

This copolymerized polyester (B) has a polyfunctional hydroxy compound structural unit having at least 3 hydroxy groups. This polyfunctional hydroxy compound constitutional unit is 0.05 to 1.0 part by mole, preferably 0.1 to 0.5 per 100 parts by mole of the dicarboxylic acid component unit.
It is desirable to be present in an amount in molar parts.

Such polyfunctional hydroxy compound constitutional units are derived from compounds such as trimethylolmethane, trimethylolethane and trimethylolpropane, and among them, trimethylolpropane is preferable.

In the copolyester (B) used in the present invention, in addition to the above-mentioned isophthalic acid and terephthalic acid as the dicarboxylic acid component, a range which does not impair the characteristics of the obtained copolyester (B), for example, 1
The other dicarboxylic acid component may be contained in an amount of not more than mol%.

Examples of such dicarboxylic acid components include component units derived from isophthalic acid, phthalic acid, 2-methylterephthalic acid, 2,6-naphthalenedicarboxylic acid and the like.

The copolymerized polyester (B) according to the present invention is a copolymerized polyester (B) obtained in addition to the above-mentioned dihydroxyethoxy resole component and ethylene glycol component as the dihydroxy compound component.
Other dihydroxy compound components may be contained in a range that does not impair the characteristics of, for example, 1 mol% or less.

Examples of such dihydroxy compound components include 1,3-propanediol, 1,4-butanediol, neopentyl glycol, cyclohexanediol, cyclohexanedimethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, 2,2-bis (4-β-hydroxyethoxyphenyl)
Propane, bis (4-β-hydroxyethoxyphenyl)
Component units derived from dihydroxy compounds having 3 to 15 carbon atoms such as sulfone are included.

The intrinsic viscosity [η] of the copolyester (B) used in the present invention is in the range of 0.5 to 1.5 dl / g, preferably 0.6 to 1.2 dl / g. desirable.

The polyethylene naphthalate, the copolyester (A), the polyethylene terephthalate and the copolyester (B) which compose the polyester bottle as described above can be produced by a conventionally known production method. Further, the polyethylene naphthalate, the copolymerized polyester (A) and the polyester resin composition include a crosslinking agent, a heat resistance stabilizer, a weather resistance stabilizer, an antistatic agent, a lubricant, a release agent, an inorganic filler, a pigment dispersant, Various compounding agents such as pigments or dyes may be blended.

The polyester bottle according to the present invention has an average crystallinity of the bottle body of 32 to 70%, preferably 3%.
It is desirable to be in the range of 5 to 65%, more preferably 40 to 60%.

The polyester bottle according to the present invention has an adsorption amount of methanol of 1500 ppm or less, preferably 1300 ppm or less, and a paraxylene adsorption amount of 300 ppm or less, measured by the method described below.
It is preferably 200 ppm or less. Further, the polyester bottle according to the present invention has an adsorption amount of methanol of 800 ppm or less after leaving the bottle in which methanol or para-xylene is adsorbed by the method described below for 4 hours under an atmosphere of 80 ° C., and adsorption of para-xylene. It is desirable that the amount is 70 ppm or less.

As the solvent used for the evaluation of the adsorption characteristics, those having a high solubility parameter and those having a low solubility parameter were selected. Solubility parameter of methanol 14.5cal ^1/2 cm ^-3/2,
p-xylene solubility parameter is 8.8 cal ^1/2 cm
^-3/2 . Solubility parameter here means (ΔE
^V E is defined as V ² / V) ^1/2 , ΔE ^V is the molar evaporation energy of the solvent, and V is the molar volume of the solvent.

The polyester bottle of the present invention has a stretching index of 130 cm defined as follows.
The above is desirable.

[0052]

[Equation 4]

The wall thickness of the polyester bottle according to the present invention as described above is the same as that of a conventionally known bottle and is usually 0.1 to 1.0 mm, preferably 0.2 to 0.8.
It is about mm.

Next, the stretching index, average crystallinity, adsorption amount of methanol and adsorption amount of paraxylene of the bottle used in the present specification will be described. [Stretching Index] The stretching index is defined as follows.

[0055]

[Equation 5]

The stretching index of the bottle according to the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view of a bottle for explaining the stretching index. As shown in FIG. 1, the bottle 1 is composed of a spout part 2, an upper shoulder part 3, a body part 4 and a bottom part 6.

A preform 7 is used when manufacturing such a bottle 1, and the preform 7 is shown by a dotted line in FIG. The internal volume of the bottle 1 as described above (internal volume of the stretched bottle) is the internal volume excluding the plug portion 2, specifically, the internal volume below the support ring 8 of the bottle 1, More specifically, it means the internal volume below the virtual straight line 9.

The inner volume of the preform 7 (the inner volume of the unstretched preform) is the inner volume excluding the plug portion 2, and specifically, the inner volume of the preform 7 below the support ring 8. Yes, and more specifically, means the internal volume of the bottle below the virtual straight line 9.

The inner surface area of the bottle 1 (the inner surface area of the stretched bottle) is the inner surface area excluding the plug portion 2, specifically, the inner surface area below the support ring 8 of the bottle 1, and more specifically. Specifically, it means the inner surface area below the virtual straight line 9.

The inner surface area of the stretched bottle (excluding the inner surface of the plug portion) is divided into minute parts by detecting the inner surface shape with a coordinate measuring machine, and the area of this minute part is integrated. It can be measured by the division method.

If the bottle has a simple shape, the body of the bottle is assumed to be a cylinder, and the lower and upper parts of the bottle are assumed to be hemispheres. (Excluding the surface).

The stretching index of the bottle as described above depends on the inner surface area of the stretched bottle (excluding the inner surface of the plug portion), the inner volume of the stretched bottle (excluding the volume of the plug portion) and the content of the unstretched preform. It can be calculated by calculating the product (excluding the plug volume), and the internal volume of the stretched bottle (excluding the plug volume) and the unstretched preform (excluding the plug volume) are It can be easily measured by adding a liquid such as.

The units of the f value and the stretching index are cm ^-1 and cm, respectively. [Average Crystallinity] The average crystallinity of the bottle is an average value of crystallinity measured for n = 3 samples prepared as described below.

[0064] excised the size of the sample of 10 × 10 mm from the specimen bottle body portion, and a sample for measurement by adhering cut sample to have a thickness of 1 mm.

Equipment X-ray diffractometer: RU-300 (manufactured by Rigaku Denki Co., Ltd.) X-ray source: CuKα point focus output: 60 kV, 300 mA Attached device: Wide-angle goniometer, rotating sample stage Optical system: Transmission method (2θscan) ) Collimator 1 mmφ detector: measurement of scintillation counter crystallinity The angle between the diffraction beam and the transmitted beam is constant at 2θ, and the diffraction intensity of the sample is measured in the range of 2θ = 5 to 35 °.

The background diffraction intensity is subtracted from the diffraction intensity measured in. The diffraction intensity curve obtained by subtraction is designated as C. The measured diffraction intensity curve of the same resin in 100% amorphous is designated as A.

The crystallinity (X _cr ) of the sample is calculated by the following formula. FIG. 2 shows an example of the X-ray diffraction intensity curve.

[0068]

[Equation 6]

[Adsorption amount of methanol and para-xylene] The adsorption amount of methanol and para-xylene is measured by a headspace gas chromatography analysis method.

Methanol (or paraxylene) 1.5
A bottle containing 1 liter is left under conditions of 25 ° C. and 50% RH for 7 days, then methanol (or paraxylene) is removed, washed with distilled water, and dried air is blown to dry the inside of the bottle. A bottle with methanol (or para-xylene) adsorbed is prepared as described above.

Next, 2.0 g of the sample was cut out from the bottle body, the cut sample was put in a 10 ml sample vial, and the temperature of the head space was set to 145 ° C.
Gas chromatographic analysis of substances that come out in 0 minutes
Determine quantitatively.

Next, the method for producing the polyester bottle according to the present invention will be specifically described. The polyester bottle according to the present invention comprises, for example, as illustrated in FIG. 1, a plug part 2, an upper shoulder part 3, a body part 4, and a bottom part 6.

To manufacture such a bottle, first,
A preform is produced from the polyester as described above, and the preform can be produced by a conventionally known method such as injection molding or extrusion molding. The heating temperature of the polyester for forming the preform is 280 to 280 when the polyester is polyethylene naphthalate.
It is in the range of 320 ° C, in the range of 270 to 300 ° C when the polyester is the copolyester (A), and in the range of 270 when it is the polyester resin composition.
It is preferably in the range of to 300 ° C.

Next, this preform is heated to a temperature suitable for stretching and stretch blown in a mold to mold a bottle. The heating temperature of the preform at this time is 120 to 18 when the polyester is polyethylene naphthalate.
0 ° C., 95 to 120 ° C. when the polyester resin is the copolyester (A), and 95 to 120 when the polyester composition is the polyester composition.
It is preferably in the range of ° C. When stretch-blow, the stretch index defined as above is 130 cm.
It is desirable that the stretch-blow is performed as described above.

The temperature of the fluid at the time of blowing is 10
It is desirable to be in the range of to 400 ° C, preferably 20 to 300 ° C. The fluid to be blown is air, nitrogen,
Examples thereof include steam and water, and among these, air is preferable.

Further, this bottle was heated at 100 to 250 ° C.
It is preferably heat-set at a mold temperature of 110 to 200 ° C. for 1 second or longer, preferably 3 seconds or longer so that the average crystallinity of the bottle body is 32 to 70%, preferably 35 to 6
The amount of methanol adsorbed on the body of the bottle is 1500 ppm or less, preferably 1300 ppm or less, and the amount of paraxylene adsorbed on it is 300 ppm or less, preferably 200 ppm or less.

When taking out the heat-set bottle from the mold, it is desirable to cool the bottle before taking it out. As a cooling method, an internal cooling method is preferable, and cooling is performed with a fluid at −200 to 50 ° C., preferably −80 ° C. to 40 ° C. from the hollow portion of the bottle. The surface temperature of the bottle at this time is 100 ° C or lower, preferably 90 ° C.
The following is desirable. The fluid used here includes air, nitrogen, water and the like, of which air is preferred.

Since such a polyester bottle has a large degree of crystallinity in the body, it is possible to obtain a bottle excellent in non-adsorption and heat resistance. Further, it is possible to prevent the bottle from being deformed or contracted by cooling the heat-set bottle from the inside and the outside and then taking it out of the mold.

[0079]

The polyester bottle according to the present invention is
Excellent in heat resistance, with little adsorption of taste and aroma components.

According to the method for producing a polyester bottle of the present invention, it is possible to obtain a bottle excellent in heat resistance with less adsorption of taste components and aroma components.

[0081]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples.

In the present invention, the heat resistance of the bottle, the adsorption property of the bottle, and the density of the bottle body were measured as follows. [Heat Resistance] The heat resistance of the bottle was evaluated by filling the bottle with hot water at 90 ° C. and comparing its deformability with the following criteria. When the deformability is small, the bottle has high heat resistance.

Very good: No deformation of the bottle was observed. Good: A part of the bottle was slightly deformed. Poor: The bottle was severely deformed and could not be actually used. [Evaluation of adsorption characteristics] Adsorption of the methanol and para-xylene Methanol or para-xylene adsorbed bottle was prepared in the same manner as the measurement of the amount, and the obtained bottle (0 h
The adsorbed amount of methanol or para-xylene of r) and the adsorbed amount of methanol or para-xylene 4 hours after the bottle was put in an air oven at 80 ° C. and put in the air oven were measured in the same manner as above. .

The case where the adsorption amount after 0 hr and 4 hr was small was determined as a bottle having excellent non-adsorption property.

[0085]

Example 1 Polyethylene terephthalate (copolymerized polyester (A)) [manufactured by Mitsui Pet Resin Co., Ltd.] containing 10 mol% of isophthalic acid component as a dicarboxylic acid constituent unit was injected by M-100A manufactured by Meiki Seisakusho Co., Ltd. A preform was obtained by molding with a molding machine. The molding temperature at this time was 290 ° C.

Next, the preform was heated by an attached infrared heater so that the surface temperature of the central portion of the preform body became 115 ° C., and LB-0 manufactured by CORPOPLAST Co., Ltd.
A bottle was molded by stretch-blowing with a molding machine. The stretching index at this time was 185 cm.

During stretching, the blow mold was heated to 150 ° C., and the bottle was brought into contact with the mold for 5 seconds to perform heat setting treatment.
Next, the bottle was cooled to a surface temperature of 100 ° C. or lower with 30 ° C. air, and then taken out from the mold.

The bottles thus obtained were evaluated for heat resistance and adsorption characteristics defined in the specification. Table 1 shows the evaluation results
And shown in Table 2.

[0089]

Example 2 Polyethylene terephthalate [J135 manufactured by Mitsui Pet Resin Co., Ltd.], 90 mol% of isophthalic acid component in the dicarboxylic acid constitutional unit, and 85% of dihydroxyethoxyresorcinol component in the dihydroxy compound constitutional unit.
A polyester resin composition consisting of polyethylene terephthalate (copolymerized polyester (B)) [manufactured by Mitsui Pet Resin Co., Ltd.] containing 0.3% by mol of trimethylolpropane in 100% by mol of a carboxylic acid constitutional unit. A bottle was molded in the same manner as in Example 1 except that it was used.

The obtained bottles were evaluated for heat resistance and adsorption characteristics defined in the specification. Table 1 shows the evaluation results
And shown in Table 2.

[0091]

Example 3 A bottle was prepared in the same manner as in Example 1 except that polyethylene naphthalate was used as the copolyester (A).

The obtained bottles were evaluated for heat resistance and adsorption characteristics defined in the specification in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0093]

Example 4 A bottle was prepared in the same manner as in Example 1 except that polyethylene terephthalate [manufactured by Eastman Kodak Co.] containing 3 mol% of cyclohexane dimethanol component in the dihydroxy compound constitutional unit was used.

Tables 1 and 2 show the results of the evaluation of the heat resistance and the adsorption characteristics defined in the specification for the obtained bottles.

[0095]

Example 5 A bottle was prepared in the same manner as in Example 1 except that the blow mold temperature during stretching was 190 ° C.

With respect to the obtained bottle, heat resistance and adsorption characteristics defined in the specification were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0097]

Example 6 A bottle was prepared in the same manner as in Example 1 except that the blow mold temperature during stretching was 230 ° C.

With respect to the obtained bottle, heat resistance and adsorption characteristics defined in the specification were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0099]

Comparative Example 1 A bottle was prepared in the same manner as in Example 1 except that polyethylene terephthalate [J135 manufactured by Mitsui Pet Resin Co., Ltd.] was used and the mold temperature was 30 ° C. and heat setting was not performed.

Tables 1 and 2 show the results of the evaluation of the heat resistance and the adsorption characteristics defined in the specification for the obtained bottles.

[0101]

[Table 1]

[0102]

[Table 2]

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a bottle for explaining a stretching index.

FIG. 2 is an X-ray diffraction intensity curve for showing a method of calculating crystallinity. In the figure, (A) is a diffraction intensity curve in a 100% amorphous state, and (C) is a diffraction intensity curve of a bottle.

[Explanation of symbols]

 1 ... Bottle 2 ... Spout 3 ... Upper shoulder 4 ... Body 6 ... Bottom

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Tomita 6-1-2 Waki, Waki-machi, Kuga-gun, Yamaguchi Mitsui Petrochemical Industry Co., Ltd.

Claims (9)

[Claims] 1. A refillable polyester bottle, which is a stretched bottle formed of polyester, wherein the average crystallinity of the bottle body is in the range of 32 to 70%. 2. The amount of adsorption of methanol on the bottle body is 15
The polyester bottle according to claim 1, which has a content of 00 ppm or less. 3. The adsorption amount of para-xylene on the bottle body is 3
The polyester bottle according to claim 1, which has a content of not more than 00 ppm. 4. The polyester bottle according to claim 1, wherein the polyester is one kind of polyester selected from the group consisting of polyethylene naphthalate, the following copolymerized polyester (A) and the following polyester resin composition; Copolyester (A): (a) a dicarboxylic acid constitutional unit comprising 80 to 100 mol% of a terephthalic acid component unit and 0 to 20 mol% of a 2,6-naphthalenedicarboxylic acid or isophthalic acid component unit, (b) Ethylene glycol component unit 80-100 mol%
And a copolymerized polyester comprising a dihydroxy compound constitutional unit comprising 20 to 0 mol% of a glycol component unit other than the ethylene glycol component unit Polyester resin composition: (I) Polyethylene terephthalate 85 to 99 wt%
And (II) (a) isophthalic acid component unit 20 to 100 mol%
And a dicarboxylic acid constituent unit consisting of 80 to 0 mol% of a terephthalic acid constituent unit, (b) dihydroxyethoxyresorcinol constituent unit of 5 to 90 mol% and a dihydroxy compound constituent of 95 to 10 mol% of an ethylene glycol constituent unit. Copolymerized polyester (B) 15 to 15 units each comprising (b) a unit and (c) a polyfunctional hydroxy compound structural unit having at least 3 hydroxy groups, and 0.05 to 1.0 parts by mol relative to 100 parts by mol of the dicarboxylic acid structural unit. 1% by weight
A composition comprising: 5. The polyester bottle according to claim 1, wherein the stretching index defined as described below is 130 cm or more. [Equation 1] 6. A polyester bottle characterized in that a preform made of polyester is heated and stretch-blown in a mold so that the crystallinity of the bottle body is in the range of 32 to 70%. Production method. 7. The method for producing a polyester bottle according to claim 6, wherein the polyester is one kind of polyester selected from the group consisting of polyethylene naphthalate, the following copolymerized polyester (A) and the following polyester resin composition. Copolyester (A): (a) a dicarboxylic acid constitutional unit comprising 80 to 100 mol% of a terephthalic acid component unit and 0 to 20 mol% of a 2,6-naphthalenedicarboxylic acid or isophthalic acid component unit; ) Ethylene glycol component unit 80 to 100 mol%
And a copolymerized polyester comprising a dihydroxy compound constitutional unit comprising 20 to 0 mol% of a glycol component unit other than the ethylene glycol component unit Polyester resin composition: (I) Polyethylene terephthalate 85 to 99 wt%
And (II) (a) isophthalic acid component unit 20 to 100 mol%
And a dicarboxylic acid constituent unit consisting of 80 to 0 mol% of a terephthalic acid constituent unit, (b) dihydroxyethoxyresorcinol constituent unit of 5 to 90 mol% and a dihydroxy compound constituent of 95 to 10 mol% of an ethylene glycol constituent unit. Copolymerized polyester (B) 15 to 15 units each comprising (b) a unit and (c) a polyfunctional hydroxy compound structural unit having at least 3 hydroxy groups, and 0.05 to 1.0 parts by mol relative to 100 parts by mol of the dicarboxylic acid structural unit. 1% by weight
A composition comprising: 8. The method for producing a polyester bottle according to claim 6, wherein the bottle body blown at the mold temperature of 100 to 250 ° C. is heat set. 9. The method for producing a polyester bottle according to claim 6, wherein the stretching index is defined as follows so that the stretching index is 130 cm or more.