JPH10337772A - Stretching blown container and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve high barrier properties by forming polymer from thermoplastic resin material containing polyglycolic acid having a repeating unit represented by a specific chemical formula, and specific ranges of melt viscosity, melting point, melt enthalpy and density of non-orientated crystallized material. SOLUTION: Polyglycolic acid is of polymer containing repeating unit represented by a specific chemical formula, and a ratio of the repeating unit in the polymer is preferably 80 wt.% or more. And, melt viscosity η measured at temperature (Tm f 20'C) and shearing velocity of 100/sec is 500 to 100,000 Pa.s, and a melting point Tm is 180 deg.C or higher. Further, melt enthalpy ΔHm is 20 J/g or more, and density of non-orientated crystallized material is 1.50 g/cm<3> or more. Thus, it is soil decomposable, has high oxygen and carbon dioxide gas barrier properties and improves mechanical strength, heat resistance and moistureproof line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch blow container formed of a thermoplastic resin material containing polyglycolic acid, and more particularly, to a soil disintegration property, a high barrier property (a carbon dioxide gas barrier property, an oxygen barrier property). A stretch blow container (stretch oriented hollow container) having high elastic modulus, high strength, heat resistance and moisture resistance, and a method for producing the same. The stretch blow container of the present invention can be used as a container for, for example, carbonated beverages, soft drinks, seasonings, edible oils, fruit juices, alcoholic beverages, detergents, cosmetics, etc. by utilizing the above-mentioned properties.

[0002]

2. Description of the Related Art In recent years, an increase in plastic waste has become a major social problem. Conventionally, many polymer materials are
Developed and manufactured for high performance and long-term stability, it is not easily degraded in the natural environment. Therefore, how to dispose of and manage a large amount of unnecessary plastic waste is a social problem on a global scale. Among these plastic wastes, hollow containers made of various synthetic resins such as polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate (PET), and polyvinyl chloride resin are bulky. This is a particular problem.

Under these circumstances, biodegradable polymers that are degraded by microorganisms in nature have attracted attention as polymer materials that do not burden the environment. The biodegradability can be evaluated by, for example, a test for disintegration in soil (disintegration in soil). However, plastic hollow containers such as PET bottles require, for example, barrier properties, toughness, heat resistance, melt processability, and economic efficiency. These requirements are fully satisfied, and biodegradability is required. The indicated hollow plastic container has not yet been obtained.

More specifically, a conventional hollow container using a biodegradable plastic has the following problems.
For example, a hollow container based on starch is unsatisfactory in terms of water resistance, barrier properties, mechanical properties, heat resistance, and mold resistance, and has a problem that melt processing is difficult and processing cost increases. Hollow containers based on cellulose are unsatisfactory in terms of barrier properties against oxygen and carbon dioxide gas and mechanical properties, and are also problematic in that melt processing is difficult and processing costs increase. A hollow container based on a microorganism-produced polyester is unsatisfactory in terms of barrier properties against oxygen and carbon dioxide and mechanical strength, and has a problem that the cost is extremely high. Hollow containers based on synthetic polyesters such as polysuccinates (JP-A-7-172425) are unsatisfactory in terms of barrier properties against oxygen and carbon dioxide, mechanical strength, and heat resistance. There is a problem that succinic acid and butanediol are considerably expensive.

Hollow containers based on polylactic acid, which is a semi-synthetic polyester, are unsatisfactory in terms of barrier properties against oxygen and carbon dioxide and mechanical strength, and have an optically active L-lactic acid used as a raw material. Requires high purity, it must be manufactured by a bioprocess called fermentation, and there is a limit to cost reduction. Furthermore, since polylactic acid has a high glass transition temperature Tg, there is also a problem that composting is difficult under ordinary composting conditions.

Recently, a biodegradable container using a lactic acid-based polymer has been proposed (JP-A-6-23828).
As a specific example, lactic acid-polyglycolic acid (weight ratio =
50:50) A hollow container based on a copolymer is disclosed (Example-6). However, such a copolymer containing a large amount of a lactic acid component generally loses crystallinity and becomes an amorphous material having a glass transition temperature Tg of about 30 to 50 ° C., so that it is brittle and has low mechanical strength. There is a problem that it is low, and has very low barrier properties against oxygen and carbon dioxide and heat resistance.

[0007] A biodegradable dripping bottle formed by blowing a polylactic acid or a copolymer of lactic acid and glycolic acid by a blow molding method has been proposed (JP-A-6-278785). A sauce bottle is a small-sized hollow container usually having an internal volume of about 5 ml or less, and is used as a small-sized packaging container for edible seasonings such as soy sauce, sauces, sauces for baking and buckwheat, and liquid spices. is there. In this publication, as a copolymer of lactic acid and glycolic acid, a synthetic absorbent tissue substitute artificial fiber cloth (trade name: VICRYL MESH) manufactured by Johnson & Johnson Medical Co., Ltd. is melted at about 200 ° C. in an extruder. The lactic acid-glycolic acid copolymer pellets obtained by cutting were used (Example 1). The lactic acid-glycolic acid copolymer used here has a low melt viscosity of about 300 Pa · s (shear rate 100 / sec), and can form a small container such as a saucer, Even if extrusion blow molding is applied, the drawdown is too intense and molding is difficult. The publication also describes that the resin was blow-molded at a resin temperature of about 175 ° C., but even if the parison is blow-molded at such a high resin temperature, substantially no molecular orientation is obtained. Only the extrusion blow container is obtained. A non-oriented extrusion blow container has poor barrier properties and heat resistance, and a hollow container having a medium size (about 25 ml) or more has insufficient mechanical properties.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high barrier property against carbon dioxide and oxygen, excellent mechanical properties, heat resistance, water vapor permeability, etc. An object of the present invention is to provide the plastic hollow container shown at a low cost. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, a stretch blow container formed of a thermoplastic resin material containing polyglycolic acid having specific physical properties has been found to be soil degradable. In addition, it has high barrier properties, excellent toughness, heat resistance, and excellent water vapor transmission resistance, and has properties that can be sufficiently substituted for plastic hollow containers that have been a problem in plastic waste. It has been found that it can be manufactured relatively inexpensively.

Polyglycolic acid can be, for example, glycolide (ie, a cyclic dimer ester of glycolic acid)
It can be obtained by heating in the presence of a catalyst (for example, a cationic catalyst such as an organic tin carboxylate, tin halide, antimony halide or the like) to perform bulk ring-opening polymerization or solution ring-opening polymerization. In order to obtain polyglycolic acid having excellent physical properties, it is preferable to use high-purity glycolide as a monomer. High-purity glycolide is prepared by mixing a glycolic acid oligomer with a high-boiling polar organic solvent and heating the mixture to a temperature at which depolymerization of the oligomer occurs under normal pressure or reduced pressure, so that the oligomer forms a solution phase. The resulting glycolide is distilled together with a high-boiling-point polar organic solvent, and the glycolide is recovered from the distillate to obtain a good productivity.

As a method for producing a stretch blow container from polyglycolic acid, for example, a composition containing polyglycolic acid alone or containing polyglycolic acid is pelletized, and the pellet is supplied to an injection molding machine or an extrusion molding machine. There is a method in which a preform is prepared, and then the preform is stretch blow-molded. In molding the preform, it is important to adjust the resin temperature to the melting point Tm of the polyglycolic acid to 255 ° C. and to perform injection or extrusion molding. In the blow molding, the preform is stretched in a longitudinal direction at a resin temperature of (Tg of polyglycolic acid + 70 ° C.) or less using a stretching rod or the like to a length of more than 1 times and 10 times or less,
Simultaneously or sequentially, air is blown to blow ratio 1.5 to
At 10, blow molding into a hollow container is performed, and heat setting is performed if necessary. Polyglycolic acid is CO, H ₂ O, and CH
It can be industrially mass-produced using an extremely inexpensive raw material such as ₂ O or ethylene glycol. Since the stretch blow container of the present invention has disintegration properties in soil, the load on the environment is small. The present invention has been completed based on these findings.

[0011]

According to the present invention, (a)
The following equation (1)

[0012]

Embedded image (B) a melt viscosity η ^*
[Measured at a temperature (melting point Tm + 20 ° C.) and a shear rate of 100 / sec] is 500 to 100,000 Pa · s, and (c) a melting point T
m is 180 ° C. or higher, and (d) melting enthalpy ΔHm is 2
0 J / g or more, and (e) the density of the non-oriented crystallized product is 1.
It is formed of a thermoplastic resin material containing polyglycolic acid of 50 g / cm ³ or more, has a tensile strength (circumferential direction) of the body side wall of 100 MPa or more, and has a carbon dioxide gas permeability (temperature of 23 ° C.) of the body side wall. Measured at a relative humidity of 80% and converted to a thickness of 50 μm) is 300 cc / m ² · day · atm
A stretch blow container characterized by the following is provided. Further, according to the present invention, (a) the following formula (1)

[0013]

Embedded image (B) a melt viscosity η ^*
[Measured at a temperature (melting point Tm + 20 ° C.) and a shear rate of 100 / sec] is 500 to 100,000 Pa · s, and (c) a melting point T
m is 180 ° C. or higher, and (d) melting enthalpy ΔHm is 2
0 J / g or more, and (e) the density of the non-oriented crystallized product is 1.
A preform is formed by molding a thermoplastic resin material containing polyglycolic acid of 50 g / cm ³ or more at a resin temperature of Tm to 255 ° C., and the preform is (glass transition temperature of polyglycolic acid Tg + 70 ° C.). At the following resin temperature, the film is stretched more than 1 time and 10 times or less in the machine direction,
Simultaneously or successively, air is blown to a blow ratio of 1.5
To 10 hollow containers, and if necessary, the crystallization temperature of polyglycolic acid Tc ₁ to (Tm + 1
(0 ° C.) for 1 second to 30 minutes.

In the stretch blow container of the present invention, the carbon dioxide gas permeability of the body side wall (measured at a temperature of 23 ° C. and a relative humidity of 80%, converted to a thickness of 50 μm) is 300 cc / m ² · da.
y · atm or less and an oxygen permeability (measured at a temperature of 23 ° C. and a relative humidity of 80%, converted to a thickness of 50 μm) of 150
cc / m ² · day · atm or less, and / or moisture permeability (measured at a temperature of 40 ° C. and a relative humidity of 90%, and a thickness of 50 μm
Is 100 g / m ² · day or less,
It can be replaced by hollow containers such as conventional polyester-based, polyvinyl chloride-based, polyamide-based multilayers, and ethylene-vinyl alcohol copolymer-based multilayers.For example, carbonated drinking water, alcoholic beverages, soft drinks, seasonings, and edible It is suitable as a container for oils. In the stretch blow container of the present invention, the heat shrinkage rate of the body side wall (under 130 ° C. for 10 minutes) is 30.
% Or less can be a substitute for a conventional hollow container requiring heat resistance.

[0015] In the stretch blow container of the present invention, when the tensile elastic modulus (circumferential direction) of the body side wall is 3.0 GPa or more, a hollow container having a small basis weight can be obtained, and the cost can be reduced. Can be. In addition, the conventional hollow container made of a lactic acid-based polymer uses L-lactic acid, which is a high-purity optically active substance obtained by a bioprocess called fermentation, as a raw material. There is. On the other hand, polyglycolic acid has a monomer glycolide having a high purity without going through a bioprocess by the “solution phase depolymerization method” (Japanese Patent Application No. 8-48000) developed by the present inventors. Can be mass-produced,
Cost reduction is possible.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Polymer Structure The polyglycolic acid used in the present invention has the following formula (1)

[0017]

Embedded image It is a polymer containing the repeating unit represented by these. In the polymer, the ratio of the repeating unit represented by the formula (1) is
Usually, it is 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more. When the proportion of the repeating unit represented by the formula (1) is less than 70% by weight, the original crystallinity of polyglycolic acid is impaired, and the oxygen and carbon dioxide gas barrier properties, tensile strength, tensile modulus, There is a possibility that heat shrinkage resistance or the like may be significantly reduced. As the repeating unit other than the repeating unit represented by the formula (1), for example, the following formula (2)

[0018]

Embedded image (Where n = 1 to 10, m = 0 to 10) a repeating unit represented by the following formula (3)

[0019]

Embedded image (Where j = 1 to 10), a repeating unit represented by the following formula (4)

[0020]

Embedded image (In the formula, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. K = 2 to 10)
A repeating unit represented by the following formula (5)

[0021]

Embedded image And a repeating unit represented by the following formula (6):

[0022]

Embedded image And a repeating unit represented by

These repeating units (2) to (6) are represented by 1
The melting point Tm of the polyglycolic acid homopolymer can be lowered by introducing at a rate of not less than% by weight. If the Tm of the polyglycolic acid decreases, the processing temperature of the polymer decreases, and the thermal decomposition during melt processing can be reduced. Further, the crystallization rate of polyglycolic acid can be controlled by copolymerization to improve extrudability and stretchability. On the other hand, these repeating units (2) to (6)
If it exceeds 0% by weight, the crystallinity inherent in polyglycolic acid may be impaired.

Polymer Physical Properties <Molecular Weight-Melt Viscosity> Polyglycolic acid used as a raw material for the stretch blow container of the present invention is a high molecular weight polymer. Melt viscosity can be used as an index of molecular weight. The polyglycolic acid used in the present invention has a temperature (Tm + 20).
° C) (ie, the temperature corresponding to the normal melt processing temperature)
And the melt viscosity η ^* measured at a shear rate of 100 / sec ^.
Is from 500 to 100,000 Pa · s, preferably from 1,000 to 50,000 Pa · s, and more preferably from 1,500 to 20,000 Pa · s. When the melt viscosity η ^{* of the} polyglycolic acid is less than 500 Pa · s, when melt-molded into a stretch blow container, the melt is draw-down, stretch orientation is difficult, crystallinity is reduced, or obtained. The mechanical properties of the stretch blown container may be insufficient, and the container may be easily broken.
On the other hand, the melt viscosity η ^{* of} polyglycolic acid is 100,00
If it exceeds 0 Pa · s, a high temperature is required for melt processing, and processing at that temperature may cause thermal degradation of polyglycolic acid.

<Thermal Properties> The melting point Tm of the polyglycolic acid used in the present invention is 180 ° C. or higher, preferably 200 ° C. or higher, more preferably 210 ° C. or higher. T
By using polyglycolic acid having a high m, a stretch blow container excellent in barrier properties, mechanical properties, and heat resistance can be obtained. The enthalpy of fusion ΔHm of the polyglycolic acid used in the present invention is 20 J / g or more, preferably 30 J / g or more, more preferably 40 J / G or more. Polyglycolic acid having a Tm of less than 180 ° C. and / or a ΔHm of less than 20 J / g has a low crystallinity due to disorder in the chemical structure in the molecule, and as a result, the Tm and / or ΔHm is low. Presumed. Therefore, a stretch blow container formed using such a polyglycolic acid may have low barrier properties, or insufficient tensile strength or tensile elastic modulus, and may also have insufficient heat resistance. is there. The melt crystallization enthalpy ΔHmc of the polyglycolic acid used in the present invention is:
It is preferably at least 10 J / g, more preferably 20 J / g.
J / g or more, most preferably 30 J / G or more.

<Density> The polyglycolic acid used in the present invention has a non-oriented crystallized product having a density of 1.50 g / cm ³ or more, preferably 1.51 g / cm ³ or more, more preferably 1.52 g / cm ³ or more. cm ³ or more. This density is 1.
It is presumed that the polyglycolic acid of less than 50 g / cm ³ has a reduced crystallinity due to disorder in the chemical structure in the molecule, and as a result, a reduced density. Therefore, a stretch blow container obtained by using such a low-density polyglycolic acid may have low crystallinity and insufficient barrier properties, tensile strength, tensile modulus, and heat resistance.

General Properties of Stretch-Blow Container <Disintegration in Soil> The stretch-blow container of the present invention is a soil-disintegrable molded article having a low environmental load. That is, when the stretch blow container made of polyglycolic acid of the present invention is buried in soil at a depth of 10 cm, it usually collapses within 24 months, preferably within 12 months, and loses its original shape. For example, in the case of a conventional polylactic acid hollow container,
Since the glass transition temperature Tg is too high, there is a problem that composting is difficult under normal conditions. On the other hand, since the stretch blow container of the present invention is formed from polyglycolic acid having a not so high Tg, composting under ordinary conditions is possible.

<Transparency> The stretch blow container of the present invention in which no inorganic filler is added or in which the amount of the inorganic filler is small is almost colorless, has high transparency, and has an extremely low haze value.

<Tensile strength> The stretch blow container of the present invention
At the time of stretch blow molding, it is necessary that the molecular chains of the polymer on the side wall of the body are sufficiently stretched and oriented. If the stretching orientation of the molecular chains is insufficient, the degree of crystallinity at the time of stretch blow molding decreases, harmful coarse spherulites are formed, and barrier properties,
The manifestation of mechanical properties and heat resistance becomes insufficient. As one of the indexes of the stretching orientation degree of the stretching blow container, the tensile strength value of the body side wall can be used. According to the invention, usually
A stretch blow container having an internal volume of about 25 ml or more, preferably about 50 ml or more can be obtained. The stretch blow container of the present invention has a high degree of orientation in which the tensile strength in the circumferential direction (lateral direction) of the body side wall is 100 MPa or more, preferably 150 MPa or more, more preferably 200 MPa or more. If the tensile strength is less than 100 MPa, the orientation of the molecular chains will be insufficient, and the barrier properties, toughness, and heat resistance will be insufficient.

The tensile strength (circumferential direction) of the body side wall is 100
In order to obtain a stretch blow container having a MPa or higher, a preform formed from a thermoplastic resin material containing polyglycolic acid is blown with air at a resin temperature of (Tg + 70 ° C.) or less, and a blow ratio (with respect to the diameter of the preform). It is preferable to carry out stretching orientation so that the ratio of the diameter of the container is 1.5 or more. If the resin temperature exceeds (Tg + 70 ° C.), the molecular chains of the polymer are too active, and the stretched orientation state is immediately relaxed even when stretch blown, and the orientation may disappear or be greatly reduced. The blow ratio is usually 1.5 to 10, preferably 1.8 to 9, and more preferably 2.0 to 8. If the blow ratio is less than 1.5, the orientation of the molecular chains becomes insufficient, the crystallinity becomes insufficient,
The formation of harmful coarse spherulites may cause insufficient tensile strength to be exhibited, and the barrier properties, heat resistance, and transparency may be insufficient.

<Barrier Property> According to the present invention, a stretch blow container having a high oxygen and carbon dioxide gas barrier property can be obtained. The stretch blow container of the present invention has an oxygen permeability (measured at a temperature of 23 ° C. and a relative humidity of 80%) of the body side wall,
Converted to a thickness of 50 μm), but usually 150 cc / m ² · da
y · atm or less, preferably 50 cc / m ² · day ·
atm or less, more preferably 20 cc / m ² · day ·
atm or less. The stretch blow container of the present invention has a carbon dioxide gas permeability of the body side wall (measured at a temperature of 23 ° C. and a relative humidity of 80% and converted to a thickness of 50 μm) of 300 cc / m ² · da.
y · atm or less, preferably 100 cc / m ² · day
· Atm or less, more preferably 30 cc / m ² · day
-Atm or less. As described above, according to the present invention, a stretch-blow container having high barrier properties against oxygen and carbon dioxide can be obtained. The stretch blow container of the present invention,
The moisture permeability of the body side wall (measured at a temperature of 40 ° C. and a relative humidity of 90%, and converted to a thickness of 50 μm) is usually 100 g / m ² · d
ay or less, preferably 50 g / m ² · day or less, more preferably 30 g / m ² · day or less.

Such a hollow container having a high barrier property is
Not only the conventional soil-disintegrable hollow containers are unique, but also conventional high-barrier plastic hollow containers (for example, polyester hollow containers,
Hollow containers having a very high barrier property, even when compared to hollow containers of a multilayer polyamide extrusion, a hollow container of vinylidene chloride, and a multilayer extrusion hollow container of an ethylene-vinyl alcohol copolymer. The stretch blow container of the present invention maintains a high barrier property even under a high humidity condition where the relative humidity (RH) is 80 to 90%. Such barrier properties are unexpected. The stretch blow container of the present invention, as it is or subjected to moisture-proof coating, moisture-proof lamination, etc., for example, as a container for carbonated drinking water, soft drink, seasoning, edible oil, liquor, fruit juice, is commonly used for PET bottles and the like. Can be replaced by a hollow container having barrier properties.

<Tensile Elastic Modulus> In the stretch blow container of the present invention, the tensile elastic modulus (circumferential direction) of the body side wall is 3.0 GPa.
As described above, it preferably has high elasticity of 3.5 GPa or more, more preferably 4.0 GPa or more. The stretch blow container of the present invention has a high elasticity at the body side wall, so that even if the thickness is reduced to about half that of the conventional hollow container, the stiffness is strong,
It is hard to be deformed even when the contents are filled. Therefore, the economic effect of reducing the wall thickness due to the high elasticity is extremely large.

<Heat Shrinkage> According to the present invention, a stretch blow container having excellent heat resistance can be obtained. Thermal shrinkage of the body side wall of the stretch blow container of the present invention (130 ° C., 10
Minute) is usually 30% or less, preferably 20% or less,
More preferably, it is as low as 10% or less. Such a hollow container having a low heat shrinkage rate is suitable as a container for foods such as seasonings that require high-temperature sterilization, for example. When a hollow container having a heat shrinkage rate of more than 30% is used at a high temperature of 130 ° C. or more, the deformation becomes too large, and a problem may occur.

Method for Producing Stretch-Blow Container <Raw Material Polymer> Polyglycolic acid used as a raw material for the stretch-blow container of the present invention can be produced by the following method. Polyglycolic acid is a glycolide (ie, 1,4
-Dioxane-2,5-dione) in the presence of a small amount of a catalyst (eg, a cationic catalyst such as an organic tin carboxylate, tin halide, antimony halide, etc.) to a temperature of about 120 ° C. to about 250 ° C. Then, it can be obtained by a method of ring-opening polymerization. The ring-opening polymerization is preferably performed by a bulk polymerization method or a solution polymerization method. The polyglycolic acid can be obtained by a polycondensation method in which glycolic acid or an alkyl glycolate is heated in the presence or absence of a catalyst to dehydrate or dealcoholate.

In order to obtain a polyglycolic acid copolymer, in the above method or the above method, as a comonomer, for example, ethylene oxalate (that is, 1,4-dioxane-2,3-dione), lactide, lactone (for example, ,
β-propiolactone, β-butyrolactone, pivalolactone, γ-butyrolactone, δ-valerolactone, β
-Methyl-δ-valerolactone, ε-caprolactone, etc.), cyclic monomers such as trimethylene carbonate and 1,3-dioxane; lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid, 6- A hydroxycarboxylic acid such as hydroxycaproic acid or an alkyl ester thereof; an aliphatic diol such as ethylene glycol or 1,4-butanediol, and an aliphatic dicarboxylic acid such as succinic acid or adipic acid or an alkyl ester thereof, etc. A molar mixture; or two or more of these may be copolymerized as appropriate with glycolide, glycolic acid, or a glycolic acid alkyl ester. The polyglycolic acid copolymer was obtained by subjecting a polyglycolic acid to a transesterification reaction with another polymer having a repeating unit selected from the formulas (2) to (5) under heating. It may be something. Of the above-mentioned production methods, the method is preferable because a high-molecular-weight polyglycolic acid is obtained.

In the above method, the glycolide (dimeric cyclic ester of glycolic acid) used as a monomer was developed by the present inventors more than that obtained by a conventional sublimation depolymerization method of glycolic acid oligomer. Those obtained by the "solution phase depolymerization method" (Japanese Patent Application No. 8-48000) are preferable because they have high purity and can be obtained in high yield and in large quantities. By using high-purity glycolide as a monomer, high-molecular-weight polyglycolic acid can be easily obtained. In the solution phase depolymerization method, (1) glycolic acid oligomer and 230
Heating a mixture comprising at least one high boiling polar organic solvent having a boiling point in the range of ~ 450 ° C under atmospheric pressure or reduced pressure to a temperature at which the depolymerization of the oligomer occurs,
(2) The residual ratio (volume ratio) of the oligomer in the melt phase is 0.
Dissolving the oligomer in the solvent until no more than 5;
(3) Further heating is continued at the same temperature to depolymerize the oligomer, (4) dimer cyclic ester (ie, glycolide) formed is distilled off together with a high boiling point polar organic solvent, and (5) distillation Recover glycolide from material.

Examples of the high boiling point polar organic solvent include bis (alkoxyalkylester) phthalate such as di (2-methoxyethyl) phthalate, alkylene glycol dibenzoate such as diethylene glycol dibenzoate, benzyl butyl phthalate and dibutyl phthalate. Aromatic phosphoric acid esters such as aromatic carboxylic acid esters and tricresyl phosphate can be mentioned, and the amount is usually 0.3 to 50 times (weight ratio) based on the oligomer. If necessary, polypropylene glycol, polyethylene glycol, tetraethylene glycol or the like can be used as a solubilizing agent for the oligomer together with the high boiling point polar organic solvent.
The depolymerization temperature of the glycolic acid oligomer is usually 230
C. or higher, preferably 230 to 320C. The depolymerization is performed under normal pressure or reduced pressure.
It is preferable to depolymerize by heating under reduced pressure of 0 kPa (1 to 900 mbar).

<Thermoplastic Resin Material> In the present invention, the thermoplastic resin material containing the specific polyglycolic acid is used as a raw material for the stretch blow container. As the thermoplastic resin material, polyglycolic acid neat resin can be used alone. Further, as the thermoplastic resin material, a composition in which an inorganic filler, another thermoplastic resin, a plasticizer, and the like are blended with polyglycolic acid within a range not to impair the object of the present invention can be used. More specifically, based on 100 parts by weight of polyglycolic acid,
A composition (compound) containing 0 to 100 parts by weight of an inorganic filler, 0 to 100 parts by weight of another thermoplastic resin, and 0 to 100 parts by weight of a plasticizer can be used.
10 inorganic fillers, other thermoplastics, or plasticizers
Exceeding 0 parts by weight may result in insufficient barrier properties, tensile strength, tensile elastic modulus, and heat shrinkage resistance of the obtained stretch blow container, and may lower melt processability.

As the inorganic filler, for example, alumina, silica, silica alumina, zirconia, titanium oxide, iron oxide, boron oxide, calcium carbonate, calcium silicate, calcium phosphate, calcium sulfate, magnesium carbonate, magnesium silicate, magnesium phosphate ,
Magnesium sulfate, kaolin, talc, mica, ferrite, carbon, silicon, silicon nitride, molybdenum disulfide,
Glass, powder such as potassium titanate, whisker, fiber and the like can be mentioned. These can be used alone or in combination of two or more. The inorganic filler is generally used in a proportion of 0 to 100 parts by weight with respect to 100 parts by weight of polyglycolic acid, but preferably 10 parts by weight or less, more preferably 5 parts by weight in consideration of barrier properties, mechanical strength and the like. It is desirable to use it in the range of not more than part by weight. When the inorganic filler is added, the lower limit is preferably 0.01 part by weight, more preferably 0.05 part by weight.

Examples of other thermoplastic resins include homopolymers and copolymers of lactic acid, homopolymers and copolymers of ethylene oxalate, homopolymers and copolymers of ε-caprolactone, and polysuccinic acid. Ester, polyhydroxybutanoic acid, hydroxybutanoic acid-hydroxyvaleric acid copolymer, cellulose acetate, polyvinyl alcohol, starch,
Polyglutamate, natural rubber, polyethylene,
Polypropylene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, polymethyl methacrylate, polystyrene, styrene-butadiene-
Styrene block copolymer, styrene-ethylene / butylene-styrene block copolymer, ABS resin, MBS
Resins and ethylene-vinyl alcohol copolymer. These thermoplastic resins can be used alone or in combination of two or more. These thermoplastic resins are usually used in a proportion of 0 to 100 parts by weight with respect to 100 parts by weight of polyglycolic acid,
In consideration of barrier properties, mechanical strength, heat resistance, soil disintegration, and the like, it is preferable to use 50 parts by weight or less, more preferably 30 parts by weight or less. The lower limit when blending another thermoplastic resin is preferably 0.1.
01 parts by weight, more preferably 0.05 parts by weight.

As the plasticizer, phthalic acid esters such as di (methoxyethyl) phthalate, dioctyl phthalate, diethyl phthalate and benzyl butyl phthalate;
Benzoic acid esters such as diethylene glycol dibenzoate and ethylene glycol dibenzoate; aliphatic dibasic acid esters such as octyl adipate and octyl sebacate; aliphatic tribasic acid esters such as tributyl acetylcitrate; dioctyl phosphate and tricresyl phosphate Phosphate plasticizers such as epoxidized soybean oil; polyalkylene glycol esters such as polyethylene glycol sebacate and polypropylene glycol laurate; These plasticizers can be used alone or in combination of two or more. The plasticizer is usually used in a proportion of 0 to 100 parts by weight with respect to 100 parts by weight of polyglycolic acid, but preferably 50 parts by weight or less in consideration of barrier properties, mechanical strength, heat resistance and the like. Preferably, it is used in a proportion of 30 parts by weight or less. The lower limit when the plasticizer is added is preferably 0.01 part by weight, more preferably 0.05 part by weight.

In the present invention, various additives such as a heat stabilizer, a light stabilizer, a moisture proofing agent, a waterproofing agent, a water repellent, a lubricant, a releasing agent, a coupling agent, a pigment and a dye may be added, if necessary. It can be added to a plastic resin material. These various additives
An effective amount is used depending on the purpose of use. The composition is supplied to a kneading extruder by a conventional method, and a polyglycolic acid and, if necessary, one or more other components such as an inorganic filler, a thermoplastic resin, a plasticizer, and various additives are supplied to a kneading extruder. Tm to 255 ° C (usually 150 to 255
C), extruded into strands, cooled, cut and pelletized.

<Manufacture of Stretch-Blow Container> The stretch-blow container of the present invention comprises a thermoplastic resin material comprising a polyglycolic acid neat resin or a composition containing the polyglycolic acid having the above-mentioned specific properties, By molding at a resin temperature of 255 ° C., a preform in a substantially amorphous state is prepared, and the preform is vertically cooled at a resin temperature of (glass transition temperature of polyglycolic acid Tg + 70 ° C.) or lower.
At the same time or sequentially, air is blown and blow-molded into a hollow container having a blow ratio of 1.5 to 10 and, if necessary, a crystallization temperature Tc ₁ of polyglycolic acid. At a temperature of (Tm + 10 ° C.)
It can be obtained by heat setting for 1 second to 30 minutes.

The resin temperature during preform (parison) molding is in the range of melting point Tm to 255 ° C. The Tm of polyglycolic acid is about 220 ° C. in the case of a homopolymer, but is generally obtained by copolymerization with a comonomer such as ethylene oxalate, lactide, lactones, trimethylene carbonate, and 1,3-dioxane. Lower than. Therefore, the resin temperature during preform molding is usually 150 to 255 ° C, preferably 190 to 250 ° C,
More preferably, it is 200 to 245 ° C. Resin temperature 2
If the temperature exceeds 55 ° C., polyglycolic acid is liable to undergo thermal decomposition, and a satisfactory preform cannot be obtained. The preform is formed as a substantially amorphous preform. When the preform is in a crystalline state,
In the next stretching step, the tension at the time of stretching becomes large, and stretching becomes difficult. A substantially amorphous preform is:
It can be obtained by quenching the molten resin.

The temperature condition of the stretch blow molding is (Tg + 7
0 ° C) or less. When the resin temperature during stretch blow is (Tg +
At a temperature exceeding 70 ° C.), the mobility of the molecular chains of the polymer is too active, and even when stretch-blown, the stretch orientation state is immediately relaxed, and the orientation may disappear or be greatly reduced. In the case of the cold parison method, after the parison obtained by injection molding or extrusion molding is once cooled and solidified, the resin temperature is Tg to (Tg +
(70 ° C.). In the case of the hot parison method, the parison obtained by injection molding or extrusion molding is cooled, but stretch blow-molded while the resin is not solidified. That is, when the preform is a hot parison, the preform is melt-molded at a temperature of Tm to 255 ° C, and then (Tg−30 ° C) to (Tg + 70).
(° C.) and stretch blow-molded while the resin does not solidify. Even if the melt-formed preform is rapidly cooled and supercooled to a temperature lower than Tg, a stretch-blow container can be manufactured by immediately performing stretch-blow molding while the resin does not solidify. The Tg of polyglycolic acid is about 38 ° C. for a homopolymer, but ethylene oxalate, lactide, lactones, trimethylene glycol, 1,3-
By copolymerizing with comonomers such as dioxane,
Its value fluctuates. Therefore, the resin temperature at the time of stretch blow molding is not more than (Tg + 70 ° C.), but preferably 30 ° C.
To 100 ° C, more preferably 35 to 90 ° C.

The preform is stretched in the longitudinal direction by more than 1 to 10 times, but in the case of a bottomed parison, it is usually stretched using a stretching rod. In the case of a hollow pipe-shaped parison, both ends are held in a holder and stretched in the length direction (longitudinal direction). The stretching ratio in the machine direction is preferably 1.
It is about 5 to 5 times. Blow ratio is usually 1.5 to 10,
Preferably it is 1.8-9, more preferably 2.0-8. If the blow ratio is less than 1.5, the orientation of the molecular chains becomes insufficient, the degree of crystallinity becomes insufficient, and harmful coarse spherulites are generated. The transparency and transparency may also be insufficient. Here, the blow ratio refers to the ratio of the diameter (maximum diameter) of the container to the diameter of the parison formed into the container in blow molding. The step of blowing by blowing air is performed at the same time as the stretching in the longitudinal direction, or after the stretching in the longitudinal direction (sequentially).

In the final step of stretch blow molding, if necessary, a temperature of Tc ₁ to (Tm + 10 ° C.) (usually 70 to 2 ° C.)
At 40 ° C.) for 1 second to 30 minutes (typically 2 seconds to 10 minutes). High barrier properties, high elasticity and high strength, with the body side wall sufficiently stretched and oriented by stretch blow molding,
A heat-resistant stretch blow container can be obtained. On the other hand, in the conventional extrusion blow molding method without the conventional stretching orientation (for example, JP-A-6-278785) and the injection blow molding method, almost no stretching orientation of the body side wall occurs during the molding of the hollow container. Or it happens only inadequately,
The resulting hollow container has unsatisfactory barrier properties, mechanical properties, and heat resistance.

The stretch blow molding method that can be employed in the present invention includes the following various methods in more detail. (1) Two-step injection / stretch blow method The thermoplastic resin material containing polyglycolic acid is
After being supplied to an injection molding machine and injection molding in a mold at a resin temperature of Tm to 255 ° C. to produce a bottomed parison, it is cooled and solidified into a preform made of a cold parison having a resin temperature of less than Tg, Then, the preform is
After reheating to a resin temperature of (Tg + 70 ° C.), the resin is moved into a blow molding mold and stretched by a stretching rod in the longitudinal direction to more than 1 time and 10 times or less, and simultaneously or successively.
Air is blown to blow-mold into a hollow container having a blow ratio of 1.5 to 10, and heat-fixed if necessary.

(2) One-step injection / stretch blow method The thermoplastic resin material containing polyglycolic acid is
After being supplied to an injection molding machine and injection molding in a mold at a resin temperature of Tm to 255 ° C. to produce a bottomed parison, it is cooled but not solidified hot parison having a resin temperature of (Tg + 70 ° C.) or less. Then, the preform is moved into a mold for blow molding, stretched by a stretching rod in a lengthwise direction of more than 1 to 10 times, and simultaneously or sequentially, air is blown to blow ratio. Blow-mold into 1.5 to 10 hollow containers and heat-fix as needed. In this method, the preform moves to the blow molding step while maintaining the preheating of the injection molding. A hot parison temperature adjustment step may be added.

(3) Two-step extrusion / stretch blow method (1) The thermoplastic resin material containing polyglycolic acid is
It is supplied to an extruder equipped with a parison die and has a Tm of 25
After forming a hollow pipe by extrusion molding at a resin temperature of 5 ° C., it is cooled and solidified to a temperature lower than Tg, cut into a predetermined length to obtain a preform made of a cold parison, and then the preform is subjected to Tg to (Tg + 70 ° C), the ends are held in a holder and stretched in the length direction by more than 1 to 10 times or less, and then one end is pinched off to form a bottom, and then blow-molded. Move into the mold,
Air is blown to blow-mold into a hollow container having a blow ratio of 1.5 to 10, and heat-fixed if necessary.

(4) Two-step extrusion / stretch blow method (No. 2) The thermoplastic resin material containing polyglycolic acid is
It is supplied to an extruder equipped with a parison die and has a Tm of 25
After forming a hollow pipe by extrusion molding at a resin temperature of 5 ° C., it is cooled and solidified to a temperature lower than Tg, cut into a predetermined length to obtain a preform made of a cold parison, and then the preform is subjected to Tg to (Tg + 70 C)), after reheating to a resin temperature of one side, pinch off one end to make it bottomed, and then move into a blow molding die, stretch in the longitudinal direction by more than 1 time to 10 times or less, Simultaneously or sequentially, air is blown to blow-mold into a hollow container having a blow ratio of 1.5 to 10, and heat-fixed if necessary.

(5) One-Step Extrusion / Stretch Blow Method (Part 1) The thermoplastic resin material containing polyglycolic acid is
It is supplied to an extruder equipped with a parison die and has a Tm of 25
After extrusion molding at a resin temperature of 5 ° C. to produce a hollow pipe, it is cooled to a resin temperature of (Tg + 70 ° C.) or less, cut into a predetermined length to obtain a preform made of a hot parison, and both ends thereof are held with a holder. Hold it and stretch it in the length direction to more than 1 time and 10 times or less, then pinch off one end to make it bottomed, move it into the blow molding die, blow air, and blow it at a blow ratio of 1.5 to Blow-mold into 10 hollow containers and heat-fix as needed. A hot parison temperature adjustment step may be added.

(6) One-Step Extrusion / Stretch Blow Method (Part 2) The thermoplastic resin material containing polyglycolic acid is
It is supplied to an extruder equipped with a parison die and has a Tm of 25
After extrusion molding at a resin temperature of 5 ° C. to produce a hollow pipe, it is cooled to a resin temperature of (Tg + 70 ° C.) or less, cut into a predetermined length to obtain a preform made of a hot parison, and one end thereof is pinched off. Then, it is moved into the blow molding die, and is vertically moved by a stretching rod.
The film is stretched to more than 10 times and not more than 10 times, and simultaneously or sequentially, air is blown to blow-mold into a hollow container having a blow ratio of 1.5 to 10, and heat-fixed if necessary. A hot parison temperature adjustment step may be added.

<Container Shape and the Like> According to the present invention, a stretch blow container having an inner volume of 25 ml or more can be obtained, but the inner volume can be appropriately determined according to the purpose of use. At the time of stretch blow molding, usually, the stretch blow container for forming the mouth and the bottom, so that it can stand upright independently,
It is preferable to have a shape having a flat portion at the bottom.
However, even if there is no flat part at the bottom such as a round bottom, by attaching an annular band (a kind of hook),
Can be upright.

Applications The stretch blow container of the present invention can be used for various applications by utilizing the characteristics of high barrier properties, high elastic modulus and high strength, heat resistance and transparency. Applications utilizing the high barrier properties include, for example, containers for carbonated drinking water, soft drinks, edible oil, fruit juice, alcoholic beverages, and the like. Applications utilizing high elasticity and high strength include, for example, containers for drinking water, detergents, and cosmetics. Examples of applications utilizing heat resistance include seasoning containers and baby bottles that require high-temperature sterilization.

[0057]

The present invention will be more specifically described below with reference to Synthesis Examples, Examples and Comparative Examples. Physical property measurement method (1) Melt viscosity η ^* Melt viscosity η ^* was measured as an index of the molecular weight of the polymer. As a sample, an amorphous sheet having a thickness of about 0.2 mm of each polymer was crystallized by heating at about 150 ° C. for 5 minutes, and a capillarograph equipped with a nozzle (D = 0.5 mm, L = 5 mm) (Toyo Seiki ( (Tm)
+ 20 ° C.) and a shear rate of 100 / sec. (2) Thermal properties As a sample, an amorphous sheet having a thickness of about 0.2 mm for each polymer was used, and a differential scanning calorimeter (DSC; Model TC-10A manufactured by Mettler) was used at 10 ° C. /
The temperature is raised to 250 ° C. at a rate of
c ₁ ), melting point (Tm), and melting enthalpy (ΔH
m) was measured. Next, the melt crystallization temperature Tmc and the melt crystallization enthalpy ΔHmc were measured in the course of cooling at a rate of 10 ° C./min from 250 ° C. However, the glass transition temperature (Tg) was measured at a heating rate of 5 ° C./min.

(3) Density of non-oriented crystallized material As a sample, an amorphous sheet having a thickness of about 0.2 mm of each polymer, which was heat-set at 150 ° C. for 5 minutes, was used according to JIS.
It was measured according to R-7222 (pycnometer method using n-butanol). (4) Tensile modulus Tensilon (Toyo Baldwin) was used.
A strip-shaped sample piece having a width of 10 mm is clamped so that the sample length becomes 30 mm, at 23 ° C., and a pulling speed of 10 mm /
Measured in minutes. The sample piece was cut out from the body side wall of the blow container, and the tensile modulus in the circumferential direction (lateral direction) was measured. (5) Tensile strength The tensile strength was measured in the same manner as for the tensile modulus, except that the tensile speed was changed to 100 mm / min.

(6) Thermal Shrinkage One end of a 10 mm-wide strip-shaped sample piece cut from the side wall of the body of the blow container is clipped, and the free sample length is 50 mm.
mm, the sample was suspended in an air-circulating gear oven at 130 ° C. for 10 minutes and heated, then the sample was taken out, and the sample length was measured to determine the shrinkage. (7) Oxygen permeability For the sample cut from the side wall of the blow container,
Using a double-sided heated permeation tester manufactured by L Science, JI
The oxygen permeability was measured under the conditions of 23 ° C. and 80% RH according to SK-7126, and converted to a thickness of 50 μm. (8) Carbon Dioxide Permeability A sample cut from the side wall of the blow container was measured for carbon dioxide permeability at 23 ° C. and 80% RH using the same measuring apparatus as for oxygen permeability, and converted to a thickness of 50 μm.

(9) Moisture Permeability For the sample cut from the side wall of the blow container,
PERMATRON- made by ODERN CONTROL
Using W3 / 30, in accordance with JIS Z-0208,
The moisture permeability was measured at 40 ° C. and 90% RH, and converted to a thickness of 50 μm. (10) Drop test A blow container is filled with 70 ml of water and has a height of 1.5 at 25 ° C.
m was dropped on a concrete floor from the position of m, and the presence or absence of breakage was examined. (11) Disintegration in soil A strip-shaped sample piece of about 3 cm cut from the body side wall of the blow container was buried at a depth of about 10 cm in the soil of the field, and was dug out every half month to observe the shape. . The time when the shape began to collapse was observed, and the case where the collapse started within 24 months was evaluated as having soil collapse.

Synthesis Example 1 Synthesis of Monomer Into a 10 liter autoclave, 5 kg of glycolic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was charged, and stirred at 170 ° C.
To 200 ° C. over about 2 hours, and condensed while distilling off the produced water. Next, 19 kPa (1
The pressure was reduced to 90 mbar, and the mixture was kept for 2 hours to distill off the low boiling components, thereby preparing a glycolic acid oligomer. The melting point Tm of the oligomer was 205 ° C. 1.2 kg of glycolic acid oligomer was charged into a 10-liter flask, and 5 kg of benzyl butyl phthalate (manufactured by Junsei Chemical Co., Ltd.) as a solvent and 150 g of polypropylene glycol (manufactured by Junsei Chemical Co., # 400) were added as a solubilizer. In a nitrogen gas atmosphere, under reduced pressure of 5 kPa (50 mbar)
Heat to 268 ° C and “solution phase depolymerization” of the oligomer
Was performed, and the produced glycolide was co-distilled with benzyl butyl phthalate. Approximately twice the volume of cyclohexane was added to the obtained co-distillate, and glycolide was precipitated from benzyl butyl phthalate and filtered. This was recrystallized using ethyl acetate and dried under reduced pressure at room temperature at about 1 kPa for 2 nights. Glycolide was obtained in about 78% yield.

[Polymer Preparation Example 1] 200 g of the glycolide obtained in Synthesis Example 1 was charged into a PFA cylinder, and dried at room temperature for about 30 minutes while blowing nitrogen gas. Next, 0.04 g of SnCl ₄ .6.5H ₂ O was added as a catalyst, and the mixture was maintained at 172 ° C. for 2 hours while blowing nitrogen gas for polymerization. After completion of the polymerization, the cylinder was cooled to room temperature, and polyglycolic acid [polymer (P-
1)] was taken out. The obtained bulk polymer is pulverized into fine particles having a size of about 3 mm or less.
The residue was dried under reduced pressure overnight to remove residual monomers. The same method was repeated to prepare a required amount of the polymer (P-1).

[Polymer Preparation Example 2] 200 g of glycolide
Instead of using a mixture of 196 g of glycolide and 4 g of L-(-) lactide (manufactured by Tokyo Chemical Industry Co., Ltd.), polymerization and post-treatment were carried out in the same manner as in Polymer Preparation Example 1 to give glycolic acid- Lactic acid copolymer [Polymer (P-
2)] was obtained. The same method was repeated to prepare a required amount of the polymer (P-2).

[Polymer Preparation Example 3] L-(-) lactide [manufactured by Tokyo Chemical Industry Co., Ltd.] was recrystallized from ethanol and purified. 198 g of the purified L-(-) lactide was charged into a PFA cylinder, and about 30
Dry at room temperature for minutes. Next, 0.048 g of tin octoate was added as a catalyst, and 13
The polymerization was maintained at 0 ° C. for 15 hours. After completion of the polymerization, the cylinder was cooled to room temperature, and the bulk polymer taken out of the cylinder was pulverized into fine particles having a size of about 3 mm or less, and dried under reduced pressure at about 100 ° C. and about 1 kPa overnight. (P-C1)] was obtained. The same method was repeated to prepare a required amount of the polymer (P-C1).

[Polymer Preparation Example 4] Recrystallized L-(-)-
35.72 g (0.248 mol) of lactide and 162.4 g (1.4 mol) of glycolide were charged into a PFA cylinder, and bis-2-methoxyethyl phthalate 17.0 was added.
ml, 0.20 ml of a 0.33 molar tin octoate toluene solution, and 0.0626 g of glycolic acid were added.
Toluene was removed under a high vacuum of 0.1 mmHg, and the atmosphere was replaced with nitrogen twice, heated at 180 ° C. for 40 minutes with stirring, and further heated for 4 hours and 20 minutes to carry out polymerization. The obtained polymer is pulverized into fine particles having a size of about 3 mm or less.
C. and vacuum drying at about 0.1 kPa for 48 hours to obtain a glycolic acid / lactic acid copolymer [polymer (P-C2)].
The same procedure was repeated to prepare the required amount of polymer (P-C2). This polymer (P-C2) is commercially available synthetic artificial tissue substitute artificial fiber cloth (registered trademark: VICRYL ME).
It is almost equivalent to the remelted pellet of SH).

[Polymer Preparation Example 5] Recrystallized L-(-)-
100 g of lactide and 100 g of glycolide were charged into a PFA cylinder, and dried at room temperature for about 30 minutes while blowing nitrogen gas. Then, tin octoate was used as a catalyst in an amount of 0.1.
048 g was added, and polymerization was carried out at 130 ° C. for 20 hours while flowing nitrogen. After the polymerization is completed, the bulk polymer taken out of the cylinder is pulverized into fine particles having a size of about 3 mm or less, and dried under reduced pressure at about 50 ° C. and about 0.1 kPa overnight to remove residual monomers. [Polymer (P-C3)] was obtained. The same procedure was repeated to prepare the required amount of polymer (P-C3). The glass transition temperature Tg of the obtained polymer was about 44 ° C., and it was amorphous and amorphous. Table 1 shows the physical properties of each polymer obtained in Polymer Preparation Examples 1 to 5.

[0067]

[Table 1] (* 1) GA = glycolide, LA = L-lactide.

Example 1 The polymer (P-1) was 3 mm
The mixture is supplied to a small twin-screw extruder equipped with a φ nozzle under a nitrogen gas flow, extruded into a strand at a melting temperature of about 230 to 240 ° C, cut by air cooling, and pelletized (No. 1).
I got This pellet (No. 1) was supplied to an injection molding machine, and a resin mold having a bottomed parison mold (temperature of about 1
0 ° C), solidified and taken out, and a preform (thickness of about 1.6 m) made of cold parison
m, outer diameter of about 1.6 cm, length of about 5 cm, and bottom spherical shape). About 45 obtained cold preforms
° C and softened by inserting a stretching rod and stretching about 2.25 times in the machine direction, and at the same time, the body outer diameter is about 4.5
cm, body length about 9cm, neck outer diameter about 1.6cm, neck length about 1cm, flat bottom center concave bottle with two halves, blow with high pressure gas at blow ratio about 2.8, The bottle is stretched and oriented in the circumferential direction (lateral direction) to form a bottle.
It was heat-set for 0 seconds, taken out of the mold, and molded into a stretch blow container. The obtained stretch blow container was transparent.

[Example 2] Except that a composition obtained by mixing 1 part by weight of dimethoxyethyl phthalate (DMEP) as a plasticizer with 100 parts by weight of the polymer (P-2) was used instead of the polymer (P-1). In the same manner as in Example 1, a pellet (No. 2) was prepared. Pellets (N
o. Using 2), a stretch blow container was formed in the same manner as in Example 1. The obtained stretch blow container was transparent.

Example 3 The pellet (No. 1) prepared in Example 1 was supplied to an injection molding machine, injected into a bottomed parison mold (at a temperature of about 30 ° C.) at a resin temperature of 235 ° C., and solidified. Take out the preform and make a hot parison preform (thickness about 1.6 mm, outer diameter about 1.6 cm, length about 5
cm, spherical bottom). Immediately, a stretching rod is inserted into the hot preform and stretched about 2.25 times in the longitudinal direction, and at the same time, the body outer diameter is about 4.5c.
m, body length of about 9cm, neck outer diameter of about 1.6cm, neck length of about 1cm, flat bottom center concave type), cut with bottle halves, blow with high pressure gas at blow ratio of about 2.8 The bottle was stretched and oriented in the circumferential direction, formed into a bottle, and further blown with high-pressure gas, heat-set the bottle at about 150 ° C. for 10 seconds, taken out of the mold, and formed a stretch blow container. This stretch blow container was transparent.

Example 4 A stretch blow container was prepared in the same manner as in Example 3 except that the pellet (No. 2) prepared in Example 2 was used instead of the pellet (No. 1). . The obtained stretch blow container was transparent.

[Comparative Example 1] The pellet (No. 1) prepared in Example 1 was prepared using an outer diameter of 1.6 cm and a clearance of 0.7.
mm extruder with a parison die
The molten parison is extruded at a resin temperature of about 235 ° C., and while maintaining the resin temperature at about 160 ° C. or higher, the parison is about 4.5 cm in trunk outer diameter, about 9 cm in trunk length, and about 1.0 cm in neck outer diameter.
6cm, neck length about 1cm, flat bottom center concave bottle 2
With a split mold (inverted), pinch off the flat bottom, simultaneously blow high-pressure gas from the neck to form a bottle, open the mold, remove the bottle, cool, and have substantially no barrel side walls. An oriented bottle was molded. The resulting bottle is
Upon cooling, it devitrified and became opaque.

[Comparative Example 2] Instead of the pellet (No. 1), the pellet (No. 2) prepared in Example 2 was used.
Except that the blow molding temperature was 150 ° C., an extrusion blow container was produced in the same manner as in Comparative Example 1. The resulting bottle devitrified upon cooling and became opaque.

Comparative Example 3 Using the polymer (P-C1) obtained in Polymer Preparation Example 3, the resin temperature during extrusion was set to about 19
A pellet (No. C1) was prepared in the same manner as in Example 1 except that the temperature was 0 ° C. This pellet (No. C)
Using 1), a stretch blow container was obtained in the same manner as in Example 1 except that the resin temperature at the time of pouring into a bottomed parison mold was about 190 ° C. and the stretch blow temperature was about 60 ° C. The obtained stretch blow container was transparent.

Comparative Example 4 A pellet (No. C2) was prepared using the polymer (P-C2) obtained in Polymer Preparation Example 4 in place of the polymer (P-1). ), Except that the extrusion blow molding was attempted in the same manner as in Comparative Example 1 except that the polymer (P-C2) was used.
Has a melt viscosity η ^* of about 300 Pa · s, which is too low for extrusion blow molding, so that the drawdown is severe and it has to be stopped.

Comparative Example 5 Using the polymer (P-C3) obtained in Polymer Preparation Example 5, the resin temperature during extrusion was set to about 20.
A pellet (No. C3) was prepared in the same manner as in Example 1 except that the temperature was 0 ° C. This pellet (No. C)
Using 3), a stretch blow container was prepared in the same manner as in Example 1 except that the resin temperature at the time of injection into the bottomed parison mold was set at about 200 ° C. and the temperature of the hot preform was set at about 70 ° C. Produced. However, glycolic acid / lactic acid (weight ratio 5
0:50) The stretch blow container obtained from the copolymer was inferior in heat resistance, gas barrier, and drop strength. Table 2 summarizes the results of these examples and comparative examples.

[0077]

[Table 2]

(Footnote) Stretching A: Two-step injection / stretch blow method (cold parison method) Stretching B: One-step injection / stretch blow method (hot parison method) Extrusion: extrusion blow molding method

[0079]

According to the present invention, there is provided a stretch blow container which is soil decomposable, has a high oxygen and carbon dioxide gas barrier property, and is excellent in mechanical strength, heat resistance and moisture resistance. The stretch blow container of the present invention has properties that can be sufficiently substituted for a plastic hollow container such as a PET bottle, which has been a problem in plastic waste, and is provided at relatively low cost. The stretch blow container of the present invention makes use of these excellent properties, for example, containers for carbonated beverages, soft drinks, edible oils, fruit juices, alcoholic beverages, drinking water, detergents, containers for cosmetics, etc. It can be used in a wide range of fields such as required seasoning containers and baby bottles.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 67:00 B29L 22:00

Claims (16)

[Claims] (A) The following formula (1): (B) a melt viscosity η ^*
[Measured at a temperature (melting point Tm + 20 ° C.) and a shear rate of 100 / sec] is 500 to 100,000 Pa · s, and (c) a melting point T
m is 180 ° C. or higher, and (d) melting enthalpy ΔHm is 2
0 J / g or more, and (e) the density of the non-oriented crystallized product is 1.
It is formed of a thermoplastic resin material containing polyglycolic acid of 50 g / cm ³ or more, has a tensile strength (circumferential direction) of the body side wall of 100 MPa or more, and has a carbon dioxide gas permeability (temperature of 23 ° C.) of the body side wall. Measured at a relative humidity of 80% and converted to a thickness of 50 μm) is 300 cc / m ² · day · atm
A stretch blow container characterized by the following. 2. The stretch blow container according to claim 1, which is disintegratable in soil. 3. The oxygen permeability (temperature: 23 ° C., relative humidity: 80%; converted to a thickness of 50 μm) of the side wall of the body is 150 cc / m.
The stretch blow container according to claim 1 or 2, wherein the stretch blow container has a value of ² * day * atm or less. 4. The moisture permeability (temperature of 40 ° C., relative humidity of 90%; converted to a thickness of 50 μm) of the body side wall is 100 g / m ² · d.
The stretch blow container according to any one of claims 1 to 3, which is not more than ay. 5. The body according to claim 1, wherein a tensile elastic modulus (circumferential direction) of the side wall of the trunk is 3.0 GPa or more.
Item 6. The stretch blow container according to item 1. 6. The heat shrinkage of the body side wall (130 ° C., 10 minutes) is 30% or less.
Item 6. The stretch blow container according to item 1. 7. The thermoplastic resin material is a polyglycolic acid alone or a composition of polyglycolic acid and at least one selected from the group consisting of an inorganic filler, another thermoplastic resin, and a plasticizer. 7. The stretch blow container according to any one of 1 to 6. 8. Polyglycolic acid is a homopolymer of glycolic acid, a glycolic acid alkyl ester or glycolide, or a glycolic acid, a glycolic acid alkyl ester or glycolide in an amount of 70% by weight or more and less than 100% by weight, ethylene oxalate, lactide, 0% by weight of at least one comonomer selected from the group consisting of lactones, trimethylene carbonate, and 1,3-dioxane
The stretch blow container according to any one of claims 1 to 7, which is a copolymer having an excess of 30% by weight or less. 9. The stretch blow container according to claim 1, having an internal volume of 25 ml or more. 10. (a) The following formula (1) (B) a melt viscosity η ^*
[Measured at a temperature (melting point Tm + 20 ° C.) and a shear rate of 100 / sec] is 500 to 100,000 Pa · s, and (c) a melting point T
m is 180 ° C. or higher, and (d) melting enthalpy ΔHm is 2
0 J / g or more, and (e) the density of the non-oriented crystallized product is 1.
A preform is formed by molding a thermoplastic resin material containing polyglycolic acid of 50 g / cm ³ or more at a resin temperature of Tm to 255 ° C., and the preform is (glass transition temperature of polyglycolic acid Tg + 70 ° C.). At the following resin temperature, the film is stretched more than 1 time and 10 times or less in the machine direction,
Simultaneously or successively, air is blown to a blow ratio of 1.5
To 10 hollow containers, and if necessary, the crystallization temperature of polyglycolic acid Tc ₁ to (Tm + 1
(0 ° C.) for 1 second to 30 minutes. 11. A thermoplastic resin material containing polyglycolic acid is injection-molded at a resin temperature of Tm to 255 ° C. to produce a bottomed parison, and then cooled to obtain a cold parison having a resin temperature of less than Tg. Then, the preform is made from Tg to (Tg + 70 ° C.)
After being reheated to a resin temperature of not more than 1 and moved into a blow molding die, it is stretched by a stretching rod in the longitudinal direction to more than 1 time and 10 times or less, and simultaneously or sequentially, air is blown to blow a blow ratio of 1.5 or more. The method for producing a stretch-blow container according to claim 10, wherein the blow-molding is carried out into hollow containers (10) to (10). 12. A thermoplastic resin material containing polyglycolic acid is injection-molded at a resin temperature of Tm to 255 ° C. to form a bottomed parison, and then cooled (Tg + 70).
° C) and a preform made of a hot parison having a resin temperature of not more than 1%. Then, the preform is moved into a mold for blow molding and stretched by a stretching rod in a lengthwise direction by more than 1 time to 10 times or less and simultaneously. The method for producing a stretch blow container according to claim 10, wherein air is blown into the hollow container having a blow ratio of 1.5 to 10 sequentially. 13. A hollow pipe is produced by extruding the thermoplastic resin material containing polyglycolic acid at a resin temperature of Tm to 255 ° C., and then cooling to a temperature lower than Tg.
It is cut into a fixed length to obtain a preform made of cold parison, and then the preform is subjected to Tg- (Tg + 70
° C), the ends are held in a holder and stretched in the length direction by more than 1 to 10 times or less, and then one end is pinched off to form a bottom, and then blow-molded. Move into the mold and blow air to blow ratio 1.5 ~
The method for producing a stretch blow container according to claim 10, wherein the blow molding is performed into 10 hollow containers. 14. A hollow pipe is produced by extruding the thermoplastic resin material containing polyglycolic acid at a resin temperature of Tm to 255 ° C., and then cooling to a temperature lower than Tg.
It is cut into a fixed length to obtain a preform made of cold parison, and then the preform is subjected to Tg- (Tg + 70
° C) resin temperature, then pinch off one end to make it bottomed, then move into the blow mold,
The stretched rod is stretched in the longitudinal direction by more than 1 time to 10 times or less, and air is blown simultaneously or sequentially to blow-mold into a hollow container having a blow ratio of 1.5 to 10.
A method for producing the stretch blow container according to the above. 15. A hollow pipe is produced by extruding the thermoplastic resin material containing polyglycolic acid at a resin temperature of Tm to 255 ° C., and then cooling the resin to a resin temperature of (Tg + 70 ° C.) or less. After cutting into a preform made of a hot parison, both ends of the preform are held by a holder and stretched in the length direction to more than 1 time and 10 times or less, and then one end is pinched off to form a bottom and then blown. Move into the molding die and blow air to blow ratio 1.5 ~ 1
The method for producing a stretch blow container according to claim 10, wherein the blow molding is performed into a hollow container of No. 0. 16. A hollow pipe is produced by extruding the thermoplastic resin material containing polyglycolic acid at a resin temperature of Tm to 255 ° C., and then cooling to a resin temperature of (Tg + 70 ° C.) or less, and After cutting into a preform made of a hot parison, one end of the preform is pinched off to form a bottom, then moved into a blow molding die, and stretched by a stretching rod to a length of more than 1 to 10 times or less. 11. The method for producing a stretch blow container according to claim 10, wherein air is blown simultaneously or sequentially to blow-mold into a hollow container having a blow ratio of 1.5 to 10.