JPH0782407A - Method for removing adsorbed material from polyester bottle - Google Patents

Abstract

PURPOSE:To quickly remove an adsorbed material from a polyester bottle to enable the reuse of the bottle by keeping a polyester bottle having a bottle body part having a specific average crystallinity in an atmosphere of a specific temperature, thereby desorbing the material adsorbed on the bottle. CONSTITUTION:A polyester resin (e.g. polyethylene terephthalate) is molded by an injection molding machine. The formed preform is heated to the surface temperature of 90-100 deg.C at the middle of the preform body part and formed by a drawing blow molding with a molding machine to obtain a polyester bottle 1 having an average crystallinity of 32-70% at the body part 4 of the bottle. Methanol (or p-xylene) is poured into the bottle 1, left standing at 25 deg.C for 7 days and discharged from the bottle. The bottle is washed with distilled water of 20 deg.C and dried to effect the adsorption of methanol (or p-xylene) to the bottle and the bottle 1 is maintained in an atmosphere of 40-150 deg.C for 4hr to quickly desorb and remove the material adsorbed on the polyester bottle 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing an adsorbed substance on a bottle which rapidly desorbs the adsorbed substance adsorbed on a polyester bottle.

[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 cleaning process and a sterilization process for removing adhering substances such as organic substances and inorganic substances adhering to the bottle or adsorbing substances such as taste components and aroma components adsorbed on the bottle. Then, it is sent to the filling process of the contents. It is important that the deposits or adsorbates inside the bottle are completely removed in the above-mentioned washing step, because after the contents are filled, they are transferred to the contents and deteriorate the aroma and taste of the contents. However, with the conventional cleaning method, it is difficult to completely remove the adsorbed material even if the adhered material can be completely removed.

As a result of intensive studies in view of the above situation, the inventors of the present invention have found that when a polyester bottle with a high degree of crystallinity in the body is kept under a specific temperature atmosphere, the adsorbed substances adsorbed on the bottle are The present invention has been completed by finding that they can be quickly desorbed.

[0005]

OBJECT OF THE INVENTION It is an object of the present invention to provide a method for removing adsorbed substances adsorbed on a polyester stretched bottle for reuse.

[0006]

SUMMARY OF THE INVENTION The method for removing polyester bottle adsorbate according to the present invention has an average crystallinity of 32 to 7 in the bottle body.
It is characterized by holding a 0% polyester bottle in an atmosphere of 40 to 150 ° C. to desorb the adsorbate adsorbed on the bottle.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The method for removing the polyester bottle adsorbate according to the present invention will be described below.

The polyester forming the polyester bottle used in the method for removing adsorbed substances from polyester bottles of the present invention includes polyethylene terephthalate, polyethylene naphthalate, copolymerized polyesters (A) to (G) and polyester resin as described below. It is preferably one type of polyester selected from the composition.

A bottle made of such polyester has, for example, a shape as shown in FIG.
It is composed of a body 4 and a bottom 6. The average crystallinity of the body 4 of the bottle 1 used in the present invention is 32 to 70%,
Preferably 35-65%, more preferably 40-60%
It is desirable to be in the range of.

Further, the average crystallinity of the spout part 2 is 0 to 7
0%, preferably in the range of 30-65%, the average crystallinity of the bottom 6 is 0-50%, preferably 30-65%
It is desirable to be in the range of.

In the present invention, the polyester bottle as described above is used at 40 ° C to 150 ° C, preferably 50 to 140 ° C.
In an atmosphere of 10 to 300 minutes, preferably 30 to 24
Hold for 0 minutes to desorb the adsorbate adsorbed on the bottle. The humidity at this time is preferably less than 50% RH.

The stretched polyester bottle used in the present invention has an average crystallinity of the body of the bottle in the range of 32 to 70%. By holding such a bottle under a specific temperature atmosphere, it is possible to quickly desorb adsorbed substances such as taste components and aroma components adsorbed on the bottle.

The average crystallinity of the body of the bottle is from 32 to
Since the polyester bottle in the range of 70% has excellent heat resistance, it does not deform due to heating. next,
The method for producing the polyester bottle used in the present invention will be described.

To produce the polyester bottle used in the present invention, for example, a preform is first produced from the following polyester, and the preform is produced by a conventionally known method such as injection molding or extrusion molding. It can be manufactured. The heating temperature of the polyester for forming the preform is preferably in the range of 270 to 300 ° C. when the polyester is polyethylene terephthalate.

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, for example, 9 when the polyester is polyethylene terephthalate.
It is preferably in the range of 5 to 120 ° C.

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 is 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, and the average crystallinity of the bottle body is 32 to 70%, preferably 35 to 6%.
5%, and more preferably 40 to 60%.

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 80 ° C.
The following is desirable. The fluid used here includes air, nitrogen, water and the like, of which air is preferred.

Next, the polyester for molding the polyester bottle used in the present invention will be described. Examples of the polyester forming the polyester bottle used in the present invention include the following polyethylene terephthalate, polyethylene naphthalate, and copolymerized polyesters (A) to (G).

[Polyethylene terephthalate] The polyethylene terephthalate forming the bottle used in the present invention is produced by using terephthalic acid and ethylene glycol as raw materials. In this polyethylene terephthalate, 20 mol% or less of other dicarboxylic acid and / Or other dihydroxy compound may be copolymerized.

Specific examples of the dicarboxylic acid used in the 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 ester 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 at 25 ° C. in o-chlorophenol) 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.

[Polyethylene Naphthalate] The polyethylene naphthalate forming the bottle used in the present invention contains 60 units of ethylene-2,6-naphthalate derived from 2,6-naphthalenedicarboxylic acid and ethylene glycol.
It is desirable that the content is at least mol%, preferably at least 80 mol%, more preferably at least 90 mol%,
Constituent units other than ethylene-2,6-naphthalate may be contained 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 polyethylene naphthalate is heated with a differential scanning calorimeter (DSC) at a rate of 10 ° C./min 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 elevated temperature 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: First, the temperature is rapidly raised from room temperature, melted and held at 290 ° C. for 10 minutes, then rapidly cooled to room temperature, and then 10 ° C. /
The apex temperature of the exothermic peak detected when the temperature is raised at a temperature raising rate of a minute is obtained.

[Copolyester (A)] Copolyester (A) forming the bottle used in the present invention.
Is formed from a terephthalic acid constituent unit, a dicarboxylic acid constituent unit containing a 2,6-naphthalenedicarboxylic acid or isophthalic acid constituent unit, and a dihydroxy compound constituent unit containing an ethylene glycol constituent unit.

The dicarboxylic acid constitutional unit constituting the copolyester (A) has a terephthalic acid component unit of 80 to 1
Present in an amount of 00 mol%, preferably 85 to 99.5 mol%, and the 2,6-naphthalenedicarboxylic acid or isophthalic acid component unit is present in an amount of 0 to 20 mol%, preferably 0.5 to 15 mol%. Existence is desirable.

In the copolyester (A) used in the present invention, in addition to the above-mentioned terephthalic acid component, 2,6-naphthalenedicarboxylic acid and isophthalic acid component as the dicarboxylic acid constituent unit, 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 dicarboxylic acid components 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, and 1,3-bis (2-hydroxyethoxy). The number of carbon atoms of benzene, 1,4-bis (2-hydroxyethoxy) benzene, 2,2-bis (4-β-hydroxyethoxyphenyl) propane, bis (4-β-hydroxyethoxyphenyl) sulfone is 3 to 3 Component units derived from 15 dihydroxy compounds and the like can be mentioned.

[Copolyester (B)] Copolyester (B) forming the bottle used in the present invention.
Is formed from a dicarboxylic acid constitutional unit, a dihydroxy compound constitutional unit, and a polyfunctional hydroxy compound constitutional unit having at least three hydroxy groups.

The dicarboxylic acid constitutional unit constituting the copolyester (B) has an isophthalic acid component unit of 20 to 1
It is desirable that the terephthalic acid component unit is present in an amount of 00 mol%, preferably 50 to 98 mol%, and 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%.

The copolyester (B) has a polyfunctional hydroxy compound structural unit having at least 3 hydroxy groups. The polyfunctional hydroxy compound constituent unit is preferably present in an amount of 0.05 to 1.0 part by mole, preferably 0.1 to 0.5 part by mole, relative to 100 parts by mole of the dicarboxylic acid component unit. .

Such a polyfunctional hydroxy compound constitutional unit is derived from a compound such as trimethylolmethane, trimethylolethane or trimethylolpropane, of which trimethylolpropane is preferred.

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

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

In the copolyester (B) according to the present invention, other than the above-mentioned dihydroxyethoxy resole component and ethylene glycol component as the dihydroxy compound component, a range that does not impair the characteristics of the resulting copolyester (B) The other dihydroxy compound component may be contained in an amount of, for example, 1 mol% or less.

Examples of such dihydroxy compound components include component units derived from the above-mentioned dihydroxy compounds having 3 to 15 carbon atoms. [Copolymerized Polyester (C)] The copolymerized polyester (C) forming the bottle used in the present invention comprises a dicarboxylic acid constituent unit containing a terephthalic acid component unit and a 2,6-naphthalenedicarboxylic acid component unit, and an ethylene glycol component. And a dihydroxy compound constitutional unit containing a unit.

The dicarboxylic acid constitutional unit constituting the copolyester (C) has a terephthalic acid component unit of 80 to 1
In an amount of 00 mol%, preferably 90-99.5 mol%,
In addition, the 2,6-naphthalenedicarboxylic acid component unit is 0 to 20
It is desirable to be present in an amount of mol%, preferably 0.5 to 10 mol%.

The copolymerized polyester (C) contains a terephthalic acid component as described above as a dicarboxylic acid component and 2,6-
In addition to the naphthalene dicarboxylic acid component, a range that does not impair the properties of the resulting copolyester (C), for example, 1
The other dicarboxylic acid component may be contained in an amount of not more than mol%.

Examples of such a dicarboxylic acid component include component units derived from isophthalic acid, phthalic acid, 2-methylterephthalic acid and the like. The copolymerized polyester (C) may be used as a dihydroxy compound component in addition to the ethylene glycol component as described above, in an amount that does not impair the properties of the obtained copolymerized polyester (C), for example, 1 mol% or less of other dihydroxy compounds. It may contain a compound component.

Examples of the dihydroxy compound component include component units derived from the above-mentioned dihydroxy compound having 3 to 15 carbon atoms. [Copolymerized Polyester (D)] The copolymerized polyester (D) that forms the bottle used in the present invention is a dihydroxy compound containing a dicarboxylic acid constituent unit containing a terephthalic acid component unit and an adipic acid component unit, and an ethylene glycol component unit. It is composed of a structural unit.

The dicarboxylic acid constitutional unit constituting the copolyester (D) has a terephthalic acid component unit of 85 to 1
In an amount of 00 mol%, preferably 90-99.5 mol%,
It is also desirable that the adipic acid component unit is present in an amount of 0 to 15 mol%, preferably 0.5 to 10 mol%.

The copolyester (D) is obtained as a dicarboxylic acid component in addition to the terephthalic acid component and the adipic acid component as described above.
Other dicarboxylic acids may be contained in a range that does not impair the characteristics of, for example, 1 mol% or less.

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.

In addition to the ethylene glycol component as the dihydroxy compound component, the copolymerized polyester (D) may be used in an amount that does not impair the characteristics of the resulting copolymerized polyester (D), for example, 1 mol% or less of another dihydroxy compound. May be contained.

Examples of such a dihydroxy compound component include component units derived from the above-mentioned dihydroxy compound having 3 to 15 carbon atoms. [Copolyester (E)] The copolyester (E) forming the bottle used in the present invention comprises a dicarboxylic acid constitutional unit containing a terephthalic acid component unit, and a dihydroxy compound constitution containing an ethylene glycol component unit and a diethylene glycol component unit. It is formed from units.

The dihydroxy compound constitutional unit constituting the copolyester (E) has an ethylene glycol component unit of 93 to 98 mol%, preferably 95 to 98 mol%, and a diethylene glycol component unit of 2 to 7 mol%. %, Preferably 2-5 mol%.

The copolyester (E) may be used as a dicarboxylic acid component in addition to the terephthalic acid component as described above, within the range not impairing the properties of the resulting copolyester (E), for example, 1 mol% or less. It may contain a dicarboxylic acid component.

Examples of such a dicarboxylic acid component include isophthalic acid, phthalic acid, 2-methylterephthalic acid, and 2,6-naphthalenedicarboxylic acid. In addition to the ethylene glycol component and the diethylene glycol component described above as the dihydroxy compound component, the copolymerized polyester (E) is in a range that does not impair the characteristics of the obtained copolymerized polyester (E), for example, in an amount of 1 mol% or less. It may contain other dihydroxy compound components.

Examples of such a dihydroxy compound component include the above-mentioned dihydroxy compound having 3 to 15 carbon atoms. [Copolymerized Polyester (F)] The copolyester (F) forming the bottle used in the present invention is a dicarboxylic acid constituent unit containing a terephthalic acid component unit, a dihydroxy compound containing an ethylene glycol component unit and a neopentyl glycol component unit. And a compound structural unit.

The dihydroxy compound constitutional unit constituting the copolyester (F) has an ethylene glycol component unit in an amount of 85 to 100 mol%, preferably 90 to 99.5 mol%, and a neopentyl glycol component unit. It is desirable to be present in an amount of 0 to 15 mol%, preferably 0.5 to 10 mol%.

The copolymerized polyester (F) may be used as a dicarboxylic acid component in addition to the above-mentioned terephthalic acid component, within the range not impairing the characteristics of the obtained copolymerized polyester (F), for example, 1 mol% or less. It may contain a dicarboxylic acid component.

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

The copolymerized polyester (F) may be used as a dihydroxy compound component in addition to the above ethylene glycol component and neopentyl glycol component, within the range not impairing the characteristics of the copolymerized polyester (F) obtained, for example, 1 mol. Other dihydroxy compound components may be contained in an amount of not more than%.

Examples of such dihydroxy compound components include 1,3-propanediol, 1,4-butanediol, 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) sulfone, etc., having 3 to 15 carbon atoms Component units derived from dihydroxy compounds are mentioned.

[Copolyester (G)] Copolyester (G) forming the bottle used in the present invention.
Is formed from a dicarboxylic acid constituent unit containing a terephthalic acid constituent unit and a dihydroxy compound constituent unit containing an ethylene glycol constituent unit and a cyclohexanedimethanol constituent unit.

The dihydroxy compound constitutional unit constituting the copolyester (G) has an ethylene glycol component unit in an amount of 85 to 100 mol%, preferably 90 to 99.5 mol%, and a cyclohexanedimethanol component unit. It is desirable to be present in an amount of 0 to 15 mol%, preferably 0.5 to 10 mol%.

The copolyester (G) may be used as a dicarboxylic acid component in addition to the terephthalic acid component as described above, in an amount other than the terephthalic acid component within a range not impairing the characteristics of the copolyester (G) obtained, for example, 1 mol% or less. It may contain a dicarboxylic acid component.

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 (G) may be used as a dihydroxy compound component in addition to the above-mentioned ethylene glycol component and cyclohexanedimethanol component, within the range not impairing the properties of the copolymerized polyester (G) obtained, for example, 1 mol. Other dihydroxy compound components may be contained in an amount of not more than%.

Examples of such dihydroxy compound components include 1,3-propanediol, 1,4-butanediol, neopentyl glycol, cyclohexanediol, 1,3-bis (2-hydroxyethoxy) benzene, 1,3 Four-
Bis (2-hydroxyethoxy) benzene, 2,2-bis (4-
β-hydroxyethoxyphenyl) propane, bis (4-
Examples thereof include dihydroxy compounds having 3 to 15 carbon atoms such as β-hydroxyethoxyphenyl) sulfone.

The above-mentioned copolymerized polyesters (A) to
The molecular weight of (G) is not particularly limited as long as it can produce various molded products such as bottles, but normally, the intrinsic viscosity [η] of the copolymerized polyester resin in the o-chlorophenol solvent is 0. 5-1.5 dl / g,
It is preferably in the range of 0.6 to 1.2 dl / g.

The polyester forming the bottle used in the present invention includes the above-mentioned polyethylene terephthalate, polyethylene naphthalate, copolymerized polyester (A) to
It may be a composition comprising two or more resins selected from (G) and the like.

As such a resin composition, polyethylene terephthalate 85 to 99% by weight, preferably 85
˜95% by weight, a copolymerized polyester (B) 15 to 1% by weight, and preferably 15 to 5% by weight.

The polyester as described above can be produced by a conventionally known production method. Further, each of the above resins, cross-linking agent, heat stabilizer, weathering stabilizer,
Antistatic agent, lubricant, release agent, inorganic filler, pigment dispersant,
Various compounding agents such as pigments or dyes can be added within a range that does not impair the object of the present invention.

The average crystallinity in the present invention is the average value of the crystallinity measured for the sample of n = 3 prepared as follows. Cut the size of the sample of 10 × 10 mm from the specimen bottle 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 equipment: Wide-angle goniometer, rotating sample stage Optical system: Transmission method (2θscan) ) Collimator 1 mmφ detector: Scintillation counter Crystallinity measurement 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.

[0080]

[Equation 1]

[0081]

EFFECT OF THE INVENTION The method for removing the adsorbed product from a polyester bottle according to the present invention is easy because the adsorbed product is desorbed by holding the polyester bottle having a high degree of crystallinity under a specific temperature atmosphere. The adsorbate adsorbed on the bottle can be removed.

The present invention is useful when the polyester bottle is reused, and the reuse bottle from which the adsorbed material is removed according to the present invention does not deteriorate the aroma and taste of the filled contents.

[0083]

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 and the adsorption property of the bottle were evaluated 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: Some of the bottle was slightly deformed Poor: The bottle was severely deformed and could not be actually used [Adsorption property evaluation] Methanol (or para-xylene)
Bottle containing 1.5 liters, 25 ℃, 50% RH
After standing for 7 days under the conditions of (1), methanol (or para-xylene) is removed, the product is washed with distilled water at 20 ° C, and the inside of the bottle is dried by blowing dry air at 30 ° C.
A bottle with methanol (or para-xylene) adsorbed is prepared as described above.

Then, the amount of methanol or paraxylene adsorbed in the obtained bottle (0 hr) and the bottle are shown in Table 2.
It was placed in an air oven at the temperature (humidity: 30% RH) shown in, and the adsorption amount of methanol or paraxylene was measured 4 hours after it was placed in the air oven.

The amount of adsorption of methanol and para-xylene is measured by a gas chromatography analysis method using a head space method. That is, 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 headspace was adjusted to 1
Determine at 45 ° C by analyzing and quantifying the substances that emerge in 30 minutes by gas chromatography.

[0088]

Example 1 Polyethylene terephthalate (J135 manufactured by Mitsui Pet Resin Co., Ltd.) was used as M-10 manufactured by Meiki Seisakusho Co., Ltd.
A preform was obtained by molding with a 0A injection molding machine. The molding temperature at this time was 290 ° C.

Next, the surface temperature of the center part of the preform body was controlled to 90 to 100 by using an infrared heater attached to the preform.
Heated up to ℃, made by CORPOPLAST L
A bottle was molded by stretch-blowing with a B-01 molding machine.

The mold is heated to 130 ° C. at the time of stretching and blowing,
The bottle was brought into contact with the mold for 5 seconds for heat setting treatment, and then the bottle was cooled to 100 ° C. or lower and taken out from the mold. The obtained bottles were evaluated for heat resistance and adsorption characteristics defined in the specification. The results are shown in Tables 1 and 2.

[0091]

[Example 2] In Example 1, the mold was set to 1 at the time of stretch blowing.
A bottle was molded in the same manner as in Example 1 except that it was heated to 50 ° C.

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

[0093]

[Embodiment 3] In Embodiment 1, the mold is set to 2 at the time of stretch blowing.
A bottle was molded in the same manner as in Example 1 except that it was heated to 00 ° C.

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

[0095]

Comparative Example 1 A bottle was prepared in the same manner as in Example 1 except that the mold temperature was set to 30 ° C. and heat setting was not performed. With respect to the prepared bottle, the heat resistance and the adsorption property defined in the specification were evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[0096]

[Table 1]

[0097]

[Table 2]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a bottle.

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 4 ... Body 6 ... Bottom

Claims (1)

[Claims] 1. The average crystallinity of the bottle body is 32 to 70.
% Of the polyester bottle is held in an atmosphere of 40 to 150 ° C. to desorb the adsorbate adsorbed on the bottle.