JP2024085669A - Preform, plastic bottle, and method for manufacturing plastic bottle - Google Patents

Abstract

The present invention provides a preform, a plastic bottle, and a method for producing a plastic bottle, which are capable of maintaining high gas barrier properties after blow molding.
[Solution] The preform 23 includes a mouth 26, a body 27 connected to the mouth 26, and a bottom 28 connected to the body 27. The mouth 26, the body 27, and the bottom 28 include an outer layer 25. The body 27 and the bottom 28 include an inner layer 24 located inside the outer layer 25. The outer layer 25 includes virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. The inner layer 24 includes polyethylene furanoate.
[Selected figure] Figure 2

Description

This disclosure relates to preforms, plastic bottles, and methods for manufacturing plastic bottles.

Polyesters such as polyethylene terephthalate are widely used in the manufacture of bottles for filling beverages and other products because they are inexpensive and have excellent mechanical properties, chemical stability, heat resistance, gas barrier properties, and transparency. In particular, there is a demand for the development of bottles with higher gas barrier properties to maintain the quality of the contents.

Bottles have been proposed that have improved gas barrier properties by providing a vapor deposition film of inorganic oxides such as silicon oxide or aluminum oxide, or a vapor deposition film of an inorganic material such as aluminum. For example, Patent Document 1 and Patent Document 2 propose plastic bottles that are provided with a vapor deposition film of an inorganic oxide to improve gas barrier properties.

JP 2001-301731 A JP 2007-223098 A

However, vapor-deposited films of inorganic substances and inorganic oxides have poor stretchability, and may not be able to follow the stretching of the preform when it is blow-molded. In this case, cracks may occur in the vapor-deposited film, and the gas barrier properties of the plastic bottle may be reduced. For this reason, when forming a vapor-deposited film on a bottle, it is preferable to form the vapor-deposited film on a bottle obtained by blow-molding a preform.

On the other hand, from the viewpoint of bottle productivity, it is desirable to impart gas barrier properties to a preform or the like before molding the bottle, and then to produce the bottle by blow molding the preform. For this reason, there is a demand for preforms that can maintain high gas barrier properties even after blow molding.

The present disclosure has been made in consideration of these points, and aims to provide a preform, a plastic bottle, and a method for manufacturing a plastic bottle that are capable of maintaining high gas barrier properties after blow molding.

A first aspect of the present disclosure is a preform comprising a mouth portion, a body portion connected to the mouth portion, and a bottom portion connected to the body portion, the mouth portion, the body portion, and the bottom portion each including an outer layer, the body portion and the bottom portion each including an inner layer located inside the outer layer, the outer layer including virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester, and the inner layer including polyethylene furanoate.

In a second aspect of the present disclosure, in the preform according to the first aspect described above, the body may have a large diameter portion located on the mouth side, a small diameter portion located on the bottom side, and a tapered portion located between the large diameter portion and the small diameter portion, the diameter of which tapers from the large diameter portion side toward the small diameter portion side.

In a third aspect of the present disclosure, in the preform according to the second aspect described above, in the large diameter section, the thickness of the inner layer may be 0.2 to 2.0 times the thickness of the outer layer, in the reduced diameter section, the thickness of the inner layer may be 0.33 to 2.0 times the thickness of the outer layer, and in the small diameter section, the thickness of the inner layer may be 0.33 to 2.0 times the thickness of the outer layer.

In a fourth aspect of the present disclosure, in the preform according to each of the first to third aspects described above, the mouth portion may have a support ring, and at least a portion of the support ring may include the inner layer.

A fifth aspect of the present disclosure is a preform comprising a mouth portion, a body portion connected to the mouth portion, and a bottom portion connected to the body portion, the body portion and the bottom portion including an outer layer, the mouth portion, the body portion and the bottom portion including an inner layer located inside the outer layer, the outer layer including polyethylene furanoate, and the inner layer including virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester.

In a sixth aspect of the present disclosure, in the preform according to the fifth aspect described above, the body may have a large diameter portion located on the mouth side, a small diameter portion located on the bottom side, and a tapered portion located between the large diameter portion and the small diameter portion, the diameter of which tapers from the large diameter portion side toward the small diameter portion side.

In a seventh aspect of the present disclosure, in the preform according to the sixth aspect described above, in the large diameter section, the thickness of the outer layer may be 0.5 to 2.0 times the thickness of the inner layer, in the reduced diameter section, the thickness of the outer layer may be 0.5 to 2.0 times the thickness of the inner layer, and in the small diameter section, the thickness of the outer layer may be 0.5 to 2.0 times the thickness of the inner layer.

In an eighth aspect of the present disclosure, in a preform according to each of the fifth to seventh aspects described above, the mouth portion may have a support ring, and at least a portion of the support ring may include the outer layer.

In a ninth aspect of the present disclosure, in the preform according to each of the fifth to eighth aspects described above, the inner surface of the outer layer may be entirely covered by the inner layer.

A tenth aspect of the present disclosure is a plastic bottle comprising a mouth, a body connected to the mouth, and a bottom connected to the body, the mouth, body, and bottom including an outer layer, the body and bottom including an inner layer located inside the outer layer, the outer layer including virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester, and the inner layer including polyethylene furanoate.

An eleventh aspect of the present disclosure is a plastic bottle comprising a mouth, a body connected to the mouth, and a bottom connected to the body, the body and the bottom including an outer layer, the mouth, the body and the bottom including an inner layer located inside the outer layer, the outer layer including polyethylene furanoate, and the inner layer including virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester.

A twelfth aspect of the present disclosure is a method for manufacturing a plastic bottle, comprising the steps of preparing a preform according to any one of the first to ninth aspects described above, heating the preform, and subjecting the preform to biaxial stretch blow molding.

According to this disclosure, high gas barrier properties can be maintained in plastic bottles.

FIG. 1 is a partial vertical cross-sectional view showing a plastic bottle according to a first embodiment of the present disclosure. FIG. 2 is a vertical cross-sectional view showing a preform according to a first embodiment of the present disclosure. FIG. 3 is a diagram showing a method for manufacturing a preform according to the first embodiment of the present disclosure. FIG. 4 is a diagram showing a method for manufacturing a preform according to the first embodiment of the present disclosure. FIG. 5 is a diagram showing a method for manufacturing a preform according to the first embodiment of the present disclosure. FIG. 6 is a diagram showing a method for manufacturing a preform according to the first embodiment of the present disclosure. FIG. 7 is a diagram showing a method for manufacturing a preform according to the first embodiment of the present disclosure. 8(a)-(d) are diagrams showing a method for manufacturing a plastic bottle according to the first embodiment of the present disclosure. FIG. 9 is a partial vertical cross-sectional view showing a plastic bottle according to a second embodiment of the present disclosure. FIG. 10 is a vertical cross-sectional view showing a preform according to a second embodiment of the present disclosure.

First embodiment Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. FIGS. 1 to 8 are diagrams showing the first embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, the present invention can be implemented by appropriately changing it within the scope of the technical idea. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values such as the dimensions of each member and the material names described in this specification are examples of embodiments, and can be appropriately selected and used without being limited thereto. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are interpreted to include substantially the same state in addition to their strict meanings.

<Plastic bottles and preforms>
First, a plastic bottle 10 according to the present embodiment and a preform 23 according to the present embodiment will be described with reference to Figures 1 and 2. In this specification, "upper" and "lower" refer to the upper and lower sides of the plastic bottle 10 and the preform 23, respectively, when they are held upright (Figures 1 and 2).

(Plastic bottles)
First, a plastic bottle 10 will be described with reference to Fig. 1. The plastic bottle 10 is a container obtained by subjecting a preform 23 to blow molding.

As shown in FIG. 1, the plastic bottle 10 has an inner layer 11 and an outer layer 12. The inner layer 11 is located inside the outer layer 12. The inner layer 11 and the outer layer 12 are integrally formed with each other.

In this embodiment, the plastic bottle 10 has a mouth 13, a body 16 connected to the mouth 13, and a bottom 17 connected to the body 16. Specifically, the plastic bottle 10 has a mouth 13, a neck 14 connected to the mouth 13, a shoulder 15 connected to the neck 14, the body 16 connected to the shoulder 15, and a bottom 17 connected to the body 16.

The mouth portion 13 has a threaded portion 13a onto which a cap (not shown) is screwed, a cap 13b provided below the threaded portion 13a, and a support ring 13c provided below the cap 13b. Contents such as liquid are filled into the plastic bottle 10 through the mouth portion 13, and a cap (not shown) is screwed onto the mouth portion 13 to produce a plastic bottle containing the contents. The shape of the mouth portion 13 may be a conventionally known shape.

The neck portion 14 is located between the support ring 13c and the shoulder portion 15 and has a generally cylindrical shape with a generally uniform diameter.

The shoulder 15 is located between the neck 14 and the body 16, and has a shape in which the outer diameter gradually expands downward.

The body 16 is connected to the mouth 13 via the neck 14 and shoulder 15. The body 16 has a cylindrical shape with a generally uniform diameter, except for the area where the pressure absorption panel 16a or horizontal groove 16b described below is formed. However, this is not limited to this, and the body 16 may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape, except for the area where the pressure absorption panel 16a or horizontal groove 16b described below is formed. Alternatively, the body 16 may have a cylindrical shape with a non-uniform horizontal cross section from top to bottom, except for the area where the pressure absorption panel 16a or horizontal groove 16b described below is formed.

The body 16 includes multiple pressure absorption panels 16a that absorb pressure changes inside the plastic bottle 10. The pressure absorption panels 16a extend in the vertical direction and are arranged side by side in the circumferential direction. These pressure absorption panels 16a mainly function to absorb reduced pressure when the pressure inside the plastic bottle 10 is reduced by deforming radially inward of the plastic bottle 10. The number of pressure absorption panels 16a is arbitrary and may be one or two or more.

In addition, horizontal grooves 16b are formed above and below the pressure absorption panel 16a of the body 16. These horizontal grooves 16b mainly serve to increase the strength of the upper and lower parts of the body 16 and prevent the upper and lower parts of the body 16 from collapsing radially inward. The horizontal grooves 16b also perform an auxiliary function of absorbing reduced pressure by contracting in the vertical direction.

The bottom 17 has a centrally located recessed portion 20 and a grounding portion 21 provided around the recessed portion 20. This makes it possible to suppress deformation of the plastic bottle 10 caused by an increase or decrease in internal pressure when the plastic bottle 10 is filled with heated contents or when the contents are heated after filling. The shape of the bottom 17 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape or a rounded bottom shape).

In this embodiment, the mouth 13, the body 16, and the bottom 17 include the outer layer 12 described above. Specifically, the mouth 13, the neck 14, the shoulder 15, the body 16, and the bottom 17 include the outer layer 12 described above. The body 16 and the bottom 17 also include the inner layer 11 described above. Specifically, a part of the support ring 13c of the mouth 13, the neck 14, the shoulder 15, the body 16, and the bottom 17 include the inner layer 11 described above. In the illustrated example, the lower half of the support ring 13c includes the inner layer 11. In other words, the inner layer 11 is provided from approximately the center of the support ring 13c in the vertical direction to the bottom 17. For this reason, the part of the plastic bottle 10 above the support ring 13c is composed of only the outer layer 12, and the part below the support ring 13c is composed of the inner layer 11 and the outer layer 12. Although not shown, the entire support ring 13c may be composed of the inner layer 11 and the outer layer 12, or the entire support ring 13c may be composed of only the outer layer 12.

Next, we will explain the inner layer 11 and outer layer 12 of the plastic bottle 10. First, we will explain the inner layer 11 of the plastic bottle 10.

(Inner layer of plastic bottle)
As shown in FIG. 1 , the inner layer 11 is provided from the lower part of the mouth portion 13 (approximately the center part in the vertical direction of the support ring 13 c ) to the bottom portion 17 .

The inner layer 11 contains polyethylene furanoate. This polyethylene furanoate has excellent gas barrier properties. Therefore, by having the inner layer 11 contain polyethylene furanoate, the gas barrier properties of the plastic bottle 10 can be improved. Furthermore, by having the gas barrier properties of the plastic bottle 10 be improved, the aroma retention of the plastic bottle 10 can be improved. Therefore, the aroma of the contents filled in the plastic bottle 10 can be retained for a long period of time. Furthermore, by having the inner layer 11 contain polyethylene furanoate, the whitening resistance and dimensional stability of the plastic bottle 10 can be improved.

Polyethylene furanoate may be a polycondensate of biomass-derived polyethylene glycol and biomass-derived furan dicarboxylic acid, or it may be a compound derived from 100% biomass. By using such a compound, the amount of fossil fuel used can be significantly reduced, making it possible to reduce the environmental burden.

Biomass-derived furandicarboxylic acid can be produced from glucose. Specifically, biomass-derived furandicarboxylic acid can be obtained by isomerizing glucose to produce fructose, dehydrating this, converting it to alcohol, and then oxidizing it.

Biomass-derived ethylene glycol is a material made from ethanol (biomass ethanol) produced using biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol into ethylene oxide using a conventional method.

The polycondensation of furandicarboxylic acid and polyethylene glycol can be carried out by a conventional method. Specifically, the above-mentioned polycondensate can be produced by a general melt polymerization method in which an esterification reaction and/or an ester exchange reaction between furandicarboxylic acid and polyethylene glycol is carried out, followed by a polycondensation reaction under reduced pressure, or by a known solution heating dehydration condensation method using an organic solvent.

The polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added when the raw materials are charged or when the pressure reduction starts.

Polymerization catalysts generally include compounds containing metal elements of Groups 1 to 14 of the periodic table, excluding hydrogen and carbon. Specific examples of polymerization catalysts include compounds containing organic groups such as carboxylates, alkoxy salts, organic sulfonates, and β-diketonate salts containing at least one metal selected from the group consisting of titanium, zirconium, tin, antimony, cerium, germanium, zinc, cobalt, manganese, iron, aluminum, magnesium, calcium, strontium, sodium, and potassium, as well as inorganic compounds such as oxides and halides of the above metals, and mixtures thereof.

The content of polyethylene furanoate in the total amount of resin material contained in the plastic bottle 10 is preferably 5% by mass or more and 80% by mass or less, and more preferably 10% by mass or more and 60% by mass or less. This can further improve the gas barrier properties of the plastic bottle 10.

The inner layer 11 may contain a resin material other than polyethylene furanoate as long as the characteristics of this embodiment are not impaired. The resin material other than polyethylene furanoate may be, for example, a polyester resin, a (meth)acrylic resin, a polyolefin resin, a vinyl resin, a cellulose resin, a nylon resin, a phenolic resin, a polyurethane resin, an epoxy resin, or an ionomer resin.

The inner layer 11 may contain additives to the extent that they do not impair the characteristics of this embodiment. Examples of additives include oxygen absorbers, carbon dioxide absorbers, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, slip agents, mold release agents, antioxidants, ion exchange agents, dispersants, UV absorbers, acetaldehyde absorbers (e.g., AA Scavengers manufactured by Color Matrix), and color pigments.

Examples of oxygen absorbers include iron-based oxygen absorbers and non-iron-based oxygen absorbers. As oxygen absorbers, non-iron-based oxygen absorbers are more preferable because they can maintain the transparency of the plastic bottle 10.

Iron-based oxygen absorbers include iron powders such as reduced iron powder, interfacial iron powder, atomized iron powder, iron grinding powder, electrolytic iron powder, and crushed iron.

Non-iron oxygen absorbents include copolymers containing ethylenic unsaturated groups. Examples of copolymers containing ethylenic unsaturated groups include polydienes such as polybutadiene, polychloroprene, poly(2-ethylbutadiene), and poly(2-butylbutadiene) that are polymerized mainly at the 1,4 positions, ring-opening metathesis polymers of cycloolefins such as polyoctenylene, polypentenylene, and polynorbornene, and styrene-diene block copolymers such as styrene-isoprene block copolymers, styrene-butadiene copolymers, and styrene-isoprene-styrene block copolymers.

The content of the oxygen absorber in the inner layer 11 is preferably 3% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 10% by mass or less.

The thickness (radial distance) of the inner layer 11 in the plastic bottle 10 is preferably 0.03 mm or more and 0.38 mm or less, and more preferably 0.03 mm or more and 0.30 mm or less, in any region of the body 16 of the plastic bottle 10. By making the thickness of the inner layer 11 0.03 mm or more, the gas barrier property of the plastic bottle 10 can be effectively increased. In addition, by making the thickness of the inner layer 11 0.38 mm or less, the cost of the plastic bottle 10 can be reduced. Here, as described above, the inner layer 11 contains polyethylene furanoate. This polyethylene furanoate is more expensive than the virgin polyester contained in the outer layer 12, which will be described later. As described above, when the thickness of the inner layer 11 is 0.38 mm or less, the amount of polyethylene furanoate used can be prevented from becoming too large. As a result, the cost of the plastic bottle 10 can be reduced. Furthermore, by making the thickness of the inner layer 11 0.38 mm or less, the plastic bottle 10 can be made thinner. The thickness of the inner layer 11 is measured in an area where the pressure absorbing panel 16a or horizontal groove 16b is not formed.

(Outer layer of plastic bottle)
Next, the outer layer 12 of the plastic bottle 10 will be described. As shown in Fig. 1, the outer layer 12 is provided from the upper end of the mouth portion 13 to the bottom portion 17. In this embodiment, the mouth portion 13, except for the lower half of the support ring 13c, is composed only of the outer layer 12.

The outer layer 12 contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester (hereinafter, simply referred to as virgin polyester, etc.). In this specification, "virgin polyester" refers to polyester that has not been subjected to a recycling process, i.e., unused polyester. In addition, in this specification, "biomass-derived polyester" refers to polyester obtained from a raw material containing a biomass-derived monomer. In addition, in this specification, "mechanically recycled polyester" refers to polyester obtained by removing contaminants inside the resin obtained from a polyester container. Mechanically recycled polyester is obtained by sorting, crushing, and washing a polyester container to remove contaminants and foreign matter, obtaining flakes, and further treating the flakes at high temperature and reduced pressure for a certain period of time to remove contaminants inside the resin. In addition, in this specification, "chemically recycled polyester" refers to polyester obtained by decomposing a polyester container to the monomer level and repolymerizing it.

From the viewpoint of recyclability, the content of virgin polyester or the like in the outer layer 12 is preferably 85 parts by mass or more, and more preferably 97 parts by mass or more, per 100 parts by mass of the total amount of the resin material contained in the outer layer 12.

When the outer layer 12 includes virgin polyester, the virgin polyester may be selected from antimony-catalyzed polyester, manganese-catalyzed polyester, titanium-catalyzed polyester, aluminum-catalyzed polyester, lithium-catalyzed polyester, and germanium-catalyzed polyester. In this specification, for example, antimony-catalyzed polyester means polyester in which an antimony catalyst was used as a polymerization catalyst during the production of the polyester. Therefore, the polyesters listed above mean polyesters in which each catalyst was used as a polymerization catalyst.

Examples of antimony catalysts include antimony trioxide, antimony pentoxide, antimony acetate, triphenylantimony, and antimony glycol.

Examples of manganese catalysts include fatty acid manganese salts such as manganese acetate, manganese carbonate, manganese chloride, manganese acetylacetonate salts, and manganese hydroxide.

Examples of titanium catalysts include titanium alkoxides such as tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, and tetrabenzyl titanate, titanium oxides obtained by hydrolysis of titanium alkoxides, titanium acetate, titanium oxalate, potassium titanium oxalate, sodium titanium oxalate, potassium titanate, sodium titanate, titanic acid-aluminum hydroxide mixture, titanium chloride, titanium chloride-aluminum chloride mixture, titanium bromide, titanium fluoride, potassium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, and titanium acetylacetonate.

Examples of aluminum catalysts include aluminum tris(acetylacetate), aluminum monoacetylacetonate bis(ethylacetoacetate), and ethylacetoacetate aluminum diisopropylate.

Examples of lithium catalysts include ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, and phenyllithium.

Examples of germanium catalysts include germanium dioxide, germanium tetroxide, germanium tetramethoxide, germanium tetraethoxide, germanium tetrapropoxide, germanium tetrabutoxide, germanium tetrapentoxide, and germanium tetrahexoxide.

In this embodiment, "polyester" means a copolymer of a dicarboxylic acid compound and a diol compound.

Examples of dicarboxylic acid compounds include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, pimelic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, adamantanedicarboxylic acid, norbornenedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodiumsulfoisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, 9,9'-bis(4-carboxyphenyl)fluorene acid, and ester derivatives thereof.

Examples of diol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalenedimethanol, decahydronaphthalenediethanol, norbornanedimethanol, norbornanediethanol, tricyclodecanedimethanol, tricyclodecaneethanol, tetracyclododecanedimethanol, tetracyclododecanediethanol, decalindimethanol, decalindiethanol, Examples include 5-methylol-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane, cyclohexanediol, bicyclohexyl-4,4'-diol, 2,2-bis(4-hydroxycyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamantanediol, paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane, and pentaerythritol.

Among polyesters, polyethylene terephthalate, which is a copolymer of terephthalic acid and ethylene glycol, or modified polyethylene terephthalate, which is a copolymer of polyethylene terephthalate and a copolymerization monomer, is preferred.

The polyester may be polyethylene terephthalate derived from biomass or may be polyethylene terephthalate derived from fossil fuel. The biomass-derived polyethylene terephthalate may be polyethylene terephthalate in which the dicarboxylic acid compound is terephthalic acid derived from fossil fuel and the diol compound is ethylene glycol derived from biomass. In this way, the outer layer 12 contains polyethylene terephthalate derived from biomass, which further reduces the environmental impact of the plastic bottle 10.

As an example, the biomass ratio of "biomass-derived polyester" is 3% or more. "Biomass ratio" is a value measured by measuring the amount of carbon derived from biomass using radioactive carbon (C14) measurement. Carbon dioxide in the atmosphere contains a certain percentage of C14 (105.5 pMC). For this reason, it is known that the C14 content in plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the percentage of carbon derived from biomass can be calculated by measuring the percentage of C14 contained in the total carbon atoms in the polyester.

For example, when the content of C14 in the polyester is P _C14 , the content of carbon derived from biomass, P _bio , can be calculated as follows.
_Pbio (%)= _Pc14 /105.5×100

The polyester may contain monomers other than the dicarboxylic acid compound and the diol compound, as long as the characteristics of this embodiment are not impaired. In this case, the content of such monomers is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably 3 mol % or less, based on the total constituent units.

The outer layer 12 may contain additives as long as they do not impair the characteristics of this embodiment. Examples of additives include oxygen absorbers, gas barrier resins (polyamides such as nylon 6, nylon 6,6, and polymetaxylylene adipamide (MXD6)), plasticizers, UV stabilizers, antioxidants, color inhibitors, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, slip agents, mold release agents, antioxidants, ion exchange agents, acetaldehyde absorbers (e.g., AA Scavengers manufactured by Color Matrix), and colorants.

The thickness (radial distance) of the outer layer 12 in the plastic bottle 10 is preferably 0.03 mm or more and 0.38 mm or less, and more preferably 0.03 mm or more and 0.30 mm or less, in any region of the body 16 of the plastic bottle 10. By making the thickness of the outer layer 12 0.03 mm or more, the cost of the plastic bottle 10 can be reduced. In other words, when the thickness of the outer layer 12 is 0.03 mm or more, the thickness of the body 16 can be set to a predetermined thickness without making the thickness of the outer layer 12 thicker than necessary. Therefore, the amount of polyethylene furanoate contained in the inner layer 11 used can be prevented from becoming too large. As a result, the cost of the plastic bottle 10 can be reduced. In addition, by making the thickness of the outer layer 12 0.38 mm or less, the plastic bottle 10 can be made thinner. The thickness of the outer layer 12 is measured in a region where the pressure absorbing panel 16a or horizontal groove 16b is not formed.

The plastic bottle 10 according to the present disclosure may further include a vapor deposition film (not shown) located on the inner surface of the inner layer 11. This can further improve the gas barrier properties of the plastic bottle 10.

Examples of the vapor deposition film include vapor deposition films made of metals such as aluminum. Other examples of the vapor deposition film include vapor deposition films made of inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide, organic silicon compounds such as hexamethyldisiloxane, and hard carbon films such as DLC (Diamond Like Carbon) films.

The hard carbon film made of DLC is also called i-carbon film or hydrogenated amorphous carbon film (a-C:H), and is an amorphous carbon film mainly composed of SP3 bonds.

The thickness of the deposited film is not particularly limited and may be, for example, 1 nm or more and 150 nm or less.

The deposition film can be formed by a conventional method, for example, physical vapor deposition methods (PVD method) such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition methods (CVD method) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

The volume/weight of such a plastic bottle 10 is preferably 5 mL/g or more and 50 mL/g or less, and more preferably 8 mL/g or more and 45 mL/g or less. By having the volume/weight of the plastic bottle 10 be 5 mL/g or more, the blow moldability of the plastic bottle 10 can be improved. Furthermore, by having the volume/weight of the plastic bottle 10 be 50 mL/g or less, the heat resistance and strength of the plastic bottle 10 can be improved.

The oxygen transmission rate of the plastic bottle 10 is preferably 0.020 cc/ ^m2 ·day·atm or less when the full capacity of the plastic bottle 10 is 280 ml. The oxygen transmission rate of the plastic bottle 10 is measured in accordance with JIS K 7126 (constant pressure method) under conditions of 23° C. and 40% RH using an oxygen transmission rate measuring device (manufactured by MOCON, product name: OX-TRAN).

The water vapor transmission rate of plastic bottle 10 is preferably 0.40 g/ ^m2 ·day or less when plastic bottle 10 has a full capacity of 280 ml. The water vapor transmission rate of plastic bottle 10 is measured using a gravimetric method under conditions of 22° C. and a humidity of 40% RH.

The carbon dioxide reduction rate of the plastic bottle 10 is preferably 24% or less, and more preferably 20% or less. The carbon dioxide reduction rate is measured as follows. First, carbonated water is filled into the plastic bottle 10 so that the gas volume is 3.4. Next, the plastic bottle 10 is sealed by screwing a cap (not shown) onto the mouth portion 13. Next, the plastic bottle 10 is left for 12 weeks under conditions of 22°C and humidity 40% RH. After that, the gas volume of the plastic bottle 10 is measured to calculate the carbon dioxide reduction rate.

(preform)
Next, the preform 23 will be described with reference to Fig. 2. The preform 23 is a member used to manufacture the plastic bottle 10. As shown in Fig. 2, the preform 23 includes an inner layer 24 and an outer layer 25. The inner layer 24 is located inside the outer layer 25. The inner layer 24 and the outer layer 25 are formed integrally with each other.

In this embodiment, the preform 23 has a mouth portion 26, a body portion 27 connected to the mouth portion 26, and a bottom portion 28 connected to the body portion 27.

Of these, the mouth portion 26 corresponds to the mouth portion 13 of the plastic bottle 10 described above, and has approximately the same shape as the mouth portion 13. That is, the mouth portion 26 has a threaded portion 26a, a cap 26b provided below the threaded portion 26a, and a support ring 26c provided below the cap 26b. The threaded portion 26a, cap 26b, and support ring 26c of the preform 23 correspond to the threaded portion 13a, cap 13b, and support ring 13c of the plastic bottle 10, respectively. Therefore, the threaded portion 26a, cap 26b, and support ring 26c of the preform 23 have approximately the same shape as the threaded portion 13a, cap 13b, and support ring 13c of the plastic bottle 10.

The body 27 corresponds to the neck 14, shoulder 15, and body 16 of the plastic bottle 10 described above. The body 27 is connected to the mouth 26 and extends downward from the mouth 26. The horizontal cross section of the body 27 is circular at any point from its upper end to its lower end. However, this is not limited to this, and the body 27 may have a cylindrical shape such as an elliptical cylindrical shape or a polygonal cylindrical shape such as a rectangular cylindrical shape.

The body 27 has a large diameter section 27a located on the mouth 26 side, a small diameter section 27b located on the bottom 28 side, and a reduced diameter section 27c located between the large diameter section 27a and the small diameter section 27b, which reduces in diameter from the large diameter section 27a side to the small diameter section 27b side.

Of these, the large diameter portion 27a is the portion of the body portion 27 with the largest outer diameter, and has a cylindrical shape with a substantially uniform outer diameter. The thickness (radial distance) of the large diameter portion 27a gradually increases toward the bottom. The height H1 (vertical distance) of the large diameter portion 27a is preferably 1 mm or more and 5 mm or less. In addition, the outer diameter D1 of the large diameter portion 27a is preferably 24.5 mm or more and 26 mm or less.

The reduced diameter portion 27c has a shape in which the outer diameter gradually decreases downward. The thickness (radial distance) of the reduced diameter portion 27c is generally constant overall. The height H2 (vertical distance) of this reduced diameter portion 27c is preferably 8 mm or more and 17 mm or less.

The small diameter portion 27b is the portion of the body 27 that has the smallest outer diameter, and has a cylindrical shape with a substantially uniform outer diameter. The thickness (radial distance) of the small diameter portion 27b is substantially constant overall. The height H3 (vertical distance) of the small diameter portion 27b is preferably 25 mm or more and 77 mm or less. In addition, the outer diameter D2 of the small diameter portion 27b is preferably 17 mm or more and 25.5 mm or less.

The bottom 28 corresponds to the bottom 17 of the plastic bottle 10 described above and has an approximately hemispherical shape.

The mouth 26, body 27, and bottom 28 of such a preform 23 are integrally formed with one another. The total height H of the body 27 and bottom 28 (the vertical distance from the bottom surface of the support ring 26c to the lowest part of the bottom 28) is preferably 60 mm or more and 130 mm or less.

In this embodiment, the mouth 26, the body 27, and the bottom 28 include the outer layer 25 described above. The body 27 and the bottom 28 also include the inner layer 24 described above. Specifically, a part of the support ring 26c of the mouth 26, the body 27, and the bottom 28 include the inner layer 24 described above. In the illustrated example, the lower half of the support ring 26c includes the inner layer 24. In other words, the inner layer 24 is provided from approximately the center of the support ring 26c in the vertical direction to the bottom 28. Therefore, the part of the preform 23 above the support ring 26c is composed of only the outer layer 25, and the part below the support ring 26c is composed of the inner layer 24 and the outer layer 25. Although not shown, the entire support ring 26c may be composed of the inner layer 24 and the outer layer 25, or the entire support ring 26c may be composed of only the outer layer 25.

Next, the inner layer 24 and outer layer 25 of the preform 23 will be described. First, the inner layer 24 of the preform 23 will be described.

(Inner layer of preform)
As shown in FIG. 2, the inner layer 24 is provided from the lower part of the mouth portion 26 (approximately the center part in the vertical direction of the support ring 26 c ) to the bottom portion 28 .

The material constituting the inner layer 24 is the same as the material constituting the inner layer 11 of the plastic bottle 10. That is, the inner layer 24 of the preform 23 contains polyethylene furanoate.

The inner layer 24 is configured so that its thickness (T1 to T3 (radial distance)) changes in the body 27 of the preform 23. In the illustrated example, in the large diameter portion 27a and the reduced diameter portion 27c, the thicknesses T1 and T2 of the inner layer 24 gradually become thinner toward the top. On the other hand, in the small diameter portion 27b, the thickness T3 of the inner layer 24 is generally constant overall. The inner layer 24 is configured so that its thickness changes in the mouth portion 26 of the preform 23. That is, in the support ring 26c of the mouth portion 26, the thickness of the inner layer 24 gradually becomes thinner toward the top. Furthermore, the thickness T4 of the inner layer 24 at the bottom portion 28 is generally constant overall.

The thickness T3 and thickness T4 of the inner layer 24 may be configured to change at the small diameter portion 27b and bottom portion 28 of the body portion 27. In this case, the thickness of the thickest portion of the inner layer 24 at the small diameter portion 27b and bottom portion 28 of the body portion 27 is preferably 100% to 110% of the thickness of the thinnest portion of the inner layer 24, and more preferably 100% to 105%. This makes it possible to prevent the flow of the injected resin from being obstructed when the inner layer 24 is produced by injection molding. Therefore, when the inner layer 24 is produced by injection molding, the injected resin is more likely to spread throughout the entire area where the inner layer 24 is to be formed. As a result, it is possible to prevent the occurrence of so-called short shots, in which the injected resin does not spread throughout the entire area where the inner layer 24 is to be formed.

The thickness T1 of the inner layer 24 in the large diameter portion 27a is preferably 0.33 mm or more and 1.67 mm or less. By making the thickness T1 of the inner layer 24 0.33 mm or more, the gas barrier properties of the plastic bottle 10 produced from the preform 23 can be improved. In addition, by making the thickness T1 of the inner layer 24 1.67 mm or less, the cost of the preform 23 can be reduced while the plastic bottle 10 produced from the preform 23 can be made thinner. The thickness T1 of the inner layer 24 in the large diameter portion 27a is the thickness measured at a position 1.5 mm from the bottom surface of the support ring 26c in the large diameter portion 27a.

The thickness T2 of the inner layer 24 at the reduced diameter portion 27c is preferably 0.58 mm or more and 2.04 mm or less. By making the thickness T2 of the inner layer 24 0.58 mm or more, the gas barrier properties of the plastic bottle 10 produced from the preform 23 can be improved. In addition, by making the thickness T2 of the inner layer 24 2.04 mm or less, the cost of the preform 23 can be reduced while the plastic bottle 10 produced from the preform 23 can be made thinner.

The thickness T3 of the inner layer 24 at the small diameter portion 27b is preferably 0.66 mm or more and 2.42 mm or less. By making the thickness T3 of the inner layer 24 0.66 mm or more, the gas barrier properties of the plastic bottle 10 produced from the preform 23 can be improved. In addition, by making the thickness T3 of the inner layer 24 2.42 mm or less, the cost of the preform 23 can be reduced while the plastic bottle 10 produced from the preform 23 can be made thinner.

The thickness T4 of the inner layer 24 at the bottom 28 is preferably 0.53 mm or more and 1.95 mm or less. By making the thickness T4 of the inner layer 24 0.53 mm or more, the gas barrier properties of the plastic bottle 10 produced from the preform 23 can be improved. In addition, by making the thickness T4 of the inner layer 24 1.95 mm or less, the cost of the preform 23 can be reduced while the plastic bottle 10 produced from the preform 23 can be made thinner.

The inner layer 24 of such a preform 23 is a layer produced by injection molding synthetic resin pellets.

(Outer layer of preform)
Next, the outer layer 25 of the preform 23 will be described. As shown in Fig. 2, the outer layer 25 is provided from the upper end of the mouth portion 26 to the bottom portion 28. In this embodiment, the mouth portion 26, except for the lower half of the support ring 26c, is composed of only the outer layer 25.

The material constituting the outer layer 25 is the same as the material constituting the outer layer 12 of the plastic bottle 10. That is, the outer layer 25 of the preform 23 contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester.

The thickness (radial distance) of the outer layer 25 of such a preform 23 may be thicker than the thickness (radial distance) of the inner layer 24 in any region where the inner layer 24 is provided.

The outer layer 25 is configured so that its thickness (t1 to t3 (radial distance)) varies in the body 27 of the preform 23. In the illustrated example, the thicknesses t1 and t3 of the outer layer 25 are generally constant in the large diameter portion 27a and the small diameter portion 27b of the body 27. On the other hand, in the reduced diameter portion 27c, the thickness t2 of the outer layer 25 gradually increases toward the top. Furthermore, the thickness t4 of the outer layer 25 is generally constant in the bottom portion 28.

The outer layer 25 of such a preform 23 is a layer produced by injection molding synthetic resin pellets. Specifically, the outer layer 25 is a layer obtained by injecting an injection resin onto the outer surface of the inner layer 24. In this way, by producing the outer layer 25 by injecting an injection resin onto the outer surface of the inner layer 24, the adhesion between the outer layer 25 and the inner layer 24 can be improved, and delamination between the inner layer 24 and the outer layer 25 can be suppressed.

Here, in the large diameter portion 27a, the thickness T1 of the inner layer 24 is preferably 0.2 to 2.0 times the thickness t1 of the outer layer 25. In this case, the thickness T1 of the inner layer 24 and the thickness t1 of the outer layer 25 in the large diameter portion 27a are measured at a position 1.5 mm from the bottom surface of the support ring 26c in the large diameter portion 27a. In addition, in the reduced diameter portion 27c, the thickness T2 of the inner layer 24 is preferably 0.33 to 2.0 times the thickness t2 of the outer layer 25. In this case, the thickness T2 of the inner layer 24 and the thickness t2 of the outer layer 25 in the reduced diameter portion 27c are measured at a position 8.0 mm from the bottom surface of the support ring 26c in the reduced diameter portion 27c. Furthermore, in the small diameter portion 27b, the thickness T3 of the inner layer 24 is preferably 0.33 to 2.0 times the thickness t3 of the outer layer 25. In this case, the thickness T13 of the inner layer 24 and the thickness t13 of the outer layer 25 in the small diameter portion 27b are measured at a position 25 mm from the bottom surface of the support ring 26c in the small diameter portion 27b. In this manner, the thickness T1 of the inner layer 24 is 0.2 times or more the thickness t1 of the outer layer 25, the thickness T2 of the inner layer 24 is 0.33 times or more the thickness t2 of the outer layer 25, and the thickness T3 of the inner layer 24 is 0.33 times or more the thickness t3 of the outer layer 25, so that the amount of polyethylene furanoate used in the preform 23 can be increased. Therefore, the gas barrier property of the plastic bottle 10 produced from the preform 23 can be improved. In addition, the thickness T1 of the inner layer 24 is 2.0 times or less the thickness t1 of the outer layer 25, the thickness T2 of the inner layer 24 is 2.0 times or less the thickness t2 of the outer layer 25, and the thickness T3 of the inner layer 24 is 2.0 times or less the thickness t3 of the outer layer 25, thereby reducing the cost of the preform 23. In addition, the ratio of the thicknesses T1 to T3 of the inner layer 24 to the thicknesses t1 to t3 of the outer layer 25 can be prevented from becoming too large, so the plastic bottle 10 produced from the preform 23 can be made thinner.

In addition, in the bottom 28, the thickness T4 of the inner layer 24 is preferably 0.33 times or more and 2.0 times or less the thickness t4 of the outer layer 25. In this way, by making the thickness T4 of the inner layer 24 0.33 times or more the thickness t4 of the outer layer 25, the amount of polyethylene furanoate used in the preform 23 can be increased. Therefore, the gas barrier properties of the plastic bottle 10 made from the preform 23 can be improved. In addition, by making the thickness T4 of the inner layer 24 2.0 times or less the thickness t4 of the outer layer 25, the cost of the preform 23 can be reduced. In addition, since the ratio of the thickness T4 of the inner layer 24 to the thickness t4 of the outer layer 25 can be prevented from becoming too large, the plastic bottle 10 made from the preform 23 can be made thinner.

Next, the operation of this embodiment configured as described above, that is, the manufacturing method of the preform 23 and the manufacturing method of the plastic bottle 10, will be explained with reference to Figures 3 to 8(a)-(d).

First, as shown in FIG. 3, a first mold assembly 70A is prepared, which includes a first cavity side mold 71 and a core side mold 73 including a core 72. Next, the core 72 is inserted into the first cavity side mold 71. In this manner, the first cavity side mold 71 and the core side mold 73 are clamped together. Here, the inner surface of the first cavity side mold 71 has a shape corresponding to the outer surface of the inner layer 24 of the preform 23, and the outer surface of the core 72 of the core side mold 73 has a shape corresponding to the inner surface of the inner layer 24 of the preform 23. In addition, a gate (injection port) 74 for injecting the injection resin is formed in the first cavity side mold 71 at a position corresponding to the bottom 28 of the preform 23.

Next, as shown in FIG. 4, injection resin is injected into the space between the first cavity side mold 71 and the core 72. At this time, with the first cavity side mold 71 and the core side mold 73 clamped together, injection resin containing polyethylene furanoate is injected into the space between the first cavity side mold 71 and the core 72 from a gate 74 provided on the first cavity side mold 71. The injection resin injected from the gate 74 enters between the first cavity side mold 71 and the core 72. This forms an inner layer 24 containing polyethylene furanoate.

Then, as shown in FIG. 5, the first cavity side mold 71 of the first mold assembly 70A is removed from the core side mold 73 and the prepared inner layer 24.

Next, as shown in FIG. 6, a second mold assembly 70B is prepared, which has a second cavity side mold 75, a core side mold 73 including a core 72, and a separable lip mold 77. At this time, the prepared inner layer 24 is attached to the core 72 of the core side mold 73. Next, the core 72 to which the inner layer 24 is attached is inserted into the second cavity side mold 75. At this time, the lip mold 77 is first attached to the core side mold 73. Next, the core 72 is brought close to the second cavity side mold 75, and the core 72 is inserted into the second cavity side mold 75. In this way, the second cavity side mold 75, the core side mold 73, and the lip mold 77 are clamped. Here, the inner surface of the second cavity side mold 75 has a shape corresponding to the outer surface of the outer layer 25 of the preform 23. Additionally, a gate (injection port) 76 for injecting the injection resin is formed in the second cavity side mold 75 at a position corresponding to the bottom 28 of the preform 23.

7, the injection resin is injected into the space between the second cavity side mold 75 and the inner layer 24 attached to the core 72. That is, the injection resin is injected onto the outer surface of the inner layer 24. At this time, with the second cavity side mold 75 etc. clamped, the injection resin is injected from the gate 76 provided on the second cavity side mold 75 into the space between the second cavity side mold 75 and the lip mold 77 and the inner layer 24 and the core side mold 73. At this time, the injection resin containing virgin polyester etc. is injected from the gate 76. The injection resin injected from the gate 76 enters between the second cavity side mold 75 and the lip mold 77 and the inner layer 24 and the core side mold 73. As a result, the outer layer 25 containing virgin polyester etc. is formed. In this way, the inner layer 24 and the outer layer 25 are formed integrally with each other, forming a preform 23 having the inner layer 24 and the outer layer 25 disposed on the outside of the inner layer 24.

Then, the obtained preform 23 is removed to the outside from the second mold assembly 70B.

Next, we will explain the manufacturing method of the plastic bottle 10.

First, the preform 23 is prepared (see FIG. 8(a)). At this time, the preform 23 is produced, for example, by the method shown in FIG. 3 to FIG. 7.

Next, the preform 23 is heated (see FIG. 8(b)). At this time, the preform 23 is heated evenly in the circumferential direction by the heating device 51 while rotating with the mouth portion 26 facing downward. The heating temperature of the preform 23 in this heating process may be, for example, 90°C to 130°C.

Then, the preform 23 is subjected to biaxial stretch blow molding (see FIG. 8(c)). At this time, the preform 23 is first mounted in a blow molding die 80 for blow molding. This blow molding die 80 has a pair of body dies 81, 82 that are separated from each other, and a bottom die 83. The body dies 81, 82 and the bottom die 83 have shapes that correspond to the neck 14, shoulder 15, body 16, and bottom 17 of the plastic bottle 10, respectively.

Next, blowing air is blown into the preform 23, causing the preform 23 to expand within the cavity of the blow molding die 80 until it becomes the molded product, the plastic bottle 10 (see FIG. 8(c)). After the plastic bottle 10 has been molded in the blow molding die 80 in this manner, the die is opened and the finished plastic bottle 10 is removed from the blow molding die 80 (see FIG. 8(d)).

In this manner, the plastic bottle 10 shown in Figure 1 is obtained.

As described above, according to this embodiment, the mouth 26, body 27, and bottom 28 of the preform 23 include the outer layer 25, and the body 27 and bottom 28 of the preform 23 include the inner layer 24 located inside the outer layer 25. Furthermore, the outer layer 25 includes virgin polyester, biomass-derived polyester, or chemically recycled polyester. This makes it possible to improve the hygiene of the plastic bottle 10. Furthermore, according to this embodiment, the outer layer 25 includes biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. This makes it possible to reduce the environmental impact of the plastic bottle 10.

The inner layer 24 also contains polyethylene furanoate. This allows high gas barrier properties to be maintained after the preform 23 is blow molded. This allows the gas barrier properties of the plastic bottle 10 produced from the preform 23 to be improved. In addition, the increased gas barrier properties of the plastic bottle 10 allow the aroma retention of the plastic bottle 10 to be improved. This allows the aroma of the contents filled in the plastic bottle 10 to be retained for a long period of time. Furthermore, since the inner layer 24 contains polyethylene furanoate, the whitening resistance and dimensional stability of the plastic bottle 10 produced from the preform 23 can be improved.

In addition, according to this embodiment, the mouth portion 26 of the preform 23 has a support ring 26c. At least a portion of the support ring 26c includes the inner layer 24. This can further improve the gas barrier properties of the plastic bottle 10 produced from the preform 23.

Second embodiment Next, a second embodiment will be described with reference to Figures 9 and 10. The second embodiment shown in Figures 9 and 10 differs from the first embodiment mainly in that the outer layer 12 contains polyethylene furanoate, and the inner layer 11 contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. In Figures 9 and 10, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Plastic bottles)
As shown in FIG. 9, in this embodiment, the body 16 and the bottom 17 include the outer layer 12. Specifically, a part of the support ring 13c of the mouth 13, the neck 14, the shoulder 15, the body 16, and the bottom 17 include the outer layer 12. In the illustrated example, the lower half of the support ring 13c includes the outer layer 12. In other words, the outer layer 12 is provided from the approximate center of the support ring 13c in the vertical direction to the bottom 17. In addition, the mouth 13, the body 16, and the bottom 17 include the inner layer 11. Specifically, the mouth 13, the neck 14, the shoulder 15, the body 16, and the bottom 17 include the inner layer 11. For this reason, the portion of the plastic bottle 10 above the support ring 13c is composed of only the inner layer 11, and the portion below the support ring 13c is composed of the inner layer 11 and the outer layer 12. Although not shown, the entire support ring 13c may be composed of the inner layer 11 and the outer layer 12, or the entire support ring 13c may be composed of only the inner layer 11.

Next, we will explain the inner layer 11 and outer layer 12 of the plastic bottle 10. First, we will explain the inner layer 11 of the plastic bottle 10.

(Inner layer of plastic bottle)
9, the inner layer 11 is provided from the upper end of the mouth portion 13 to the bottom portion 17. In this embodiment, the mouth portion 13 is formed only by the inner layer 11 except for the lower half of the support ring 13c.

The inner layer 11 contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester.

The material constituting the inner layer 11 of the plastic bottle 10 according to the second embodiment may be the same as the material constituting the outer layer 12 of the plastic bottle 10 according to the first embodiment described above.

The thickness (radial distance) of the inner layer 11 in the plastic bottle 10 is preferably 0.03 mm or more and 0.33 mm or less, and more preferably 0.03 mm or more and 0.30 mm or less, in any region of the body 16 of the plastic bottle 10. By making the thickness of the inner layer 11 0.03 mm or more, the cost of the plastic bottle 10 can be reduced. Furthermore, by making the thickness of the inner layer 11 0.33 mm or less, the plastic bottle 10 can be made thinner. The thickness of the inner layer 11 is measured in a region where the pressure absorbing panel 16a or horizontal groove 16b is not formed.

(Outer layer of plastic bottle)
Next, the outer layer 12 of the plastic bottle 10 will be described. As shown in Fig. 9, the outer layer 12 is provided from the lower part of the mouth portion 13 (approximately the center part in the vertical direction of the support ring 13c) to the bottom portion 17.

The outer layer 12 contains polyethylene furanoate. This improves the gas barrier properties of the plastic bottle 10 of this embodiment. In addition, by improving the gas barrier properties of the plastic bottle 10, the aroma retention of the plastic bottle 10 can be improved. As a result, the aroma of the contents filled in the plastic bottle 10 can be retained for a long period of time. Furthermore, since the outer layer 12 contains polyethylene furanoate, the whitening resistance and dimensional stability of the plastic bottle 10 can be improved.

Polyethylene furanoate may be a polycondensate of biomass-derived polyethylene glycol and biomass-derived furan dicarboxylic acid, or it may be a compound derived from 100% biomass. By using such a compound, the amount of fossil fuel used can be significantly reduced, making it possible to reduce the environmental burden.

The material constituting the outer layer 12 of the plastic bottle 10 according to the second embodiment may be the same as the material constituting the inner layer 11 of the plastic bottle 10 according to the first embodiment described above.

In this embodiment, the entire inner surface of the outer layer 12 is covered by the inner layer 11. This makes it possible to reduce the cost of the plastic bottle 10. In addition, because the entire inner surface of the outer layer 12 is covered by the inner layer 11, the area that comes into contact with the contents can be covered by the inner layer 11. Therefore, when the inner layer 11 contains virgin polyester, biomass-derived polyester, or chemically recycled polyester, the hygiene of the plastic bottle 10 can be further improved.

The thickness (radial distance) of the outer layer 12 of the plastic bottle 10 is preferably 0.03 mm or more and 0.33 mm or less, and more preferably 0.03 mm or more and 0.30 mm or less, in any region of the body 16 of the plastic bottle 10. By making the thickness of the outer layer 12 0.03 mm or more, the gas barrier properties of the plastic bottle 10 can be effectively improved. Furthermore, by making the thickness of the outer layer 12 0.33 mm or less, the plastic bottle 10 can be made thinner while keeping the cost of the plastic bottle 10 down. The thickness of the outer layer 12 is measured in a region where the pressure absorbing panel 16a or horizontal groove 16b is not formed.

(preform)
Next, the preform 23 will be described with reference to FIG. 10. As shown in FIG. 10, in this embodiment, the body 27 and the bottom 28 include the outer layer 25. Specifically, a part of the support ring 26c of the mouth 26, the body 27 and the bottom 28 include the outer layer 25. In the illustrated example, the lower half of the support ring 26c includes the outer layer 25. In other words, the outer layer 25 is provided from the approximately center of the support ring 26c in the vertical direction to the bottom 28. In addition, the mouth 26, the body 27 and the bottom 28 include the inner layer 24. Therefore, the part above the support ring 26c of the preform 23 is composed of only the inner layer 24, and the part below the support ring 26c is composed of the inner layer 24 and the outer layer 25. Although not shown, the entire support ring 26c may be composed of the inner layer 24 and the outer layer 25, or the entire support ring 26c may be composed of only the inner layer 24.

Next, the inner layer 24 and outer layer 25 of the preform 23 will be described. First, the inner layer 24 of the preform 23 will be described.

(Inner layer of preform)
10, the inner layer 24 is provided from the upper end of the mouth portion 26 to the bottom portion 28. In the present embodiment, the mouth portion 26 is formed only by the inner layer 24 except for the lower half of the support ring 26c.

The material constituting the inner layer 24 is the same as the material constituting the inner layer 11 of the plastic bottle 10. That is, the inner layer 24 of the preform 23 contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester.

In the illustrated example, the inner layer 24 has a generally constant thickness (T11 to T13 (radial distance)) in the body portion 27 of the preform 23. However, the inner layer 24 may be configured so that the thickness (T11 to T13) varies in the body portion 27 of the preform 23. Furthermore, the thickness T14 of the inner layer 24 in the bottom portion 28 is generally constant.

It is preferable that the thickness T11 of the inner layer 24 is 0.67 mm or more and 1.67 mm or less. By making the thickness T11 of the inner layer 24 0.67 mm or more, the cost of the preform 23 can be reduced. In addition, by making the thickness T11 of the inner layer 24 1.67 mm or less, the plastic bottle 10 produced from the preform 23 can be made thin-walled.

It is preferable that the thickness T12 of the inner layer 24 is 0.78 mm or more and 2.04 mm or less. By making the thickness T12 of the inner layer 24 0.78 mm or more, the cost of the preform 23 can be reduced. In addition, by making the thickness T12 of the inner layer 24 2.04 mm or less, the plastic bottle 10 produced from the preform 23 can be made thin-walled.

It is preferable that the thickness T13 of the inner layer 24 is 0.88 mm or more and 2.42 mm or less. By making the thickness T13 of the inner layer 24 0.88 mm or more, the cost of the preform 23 can be reduced. In addition, by making the thickness T13 of the inner layer 24 2.42 mm or less, the plastic bottle 10 produced from the preform 23 can be made thin-walled.

It is preferable that the thickness T14 of the inner layer 24 is 0.70 mm or more and 1.95 mm or less. By making the thickness T14 of the inner layer 24 0.70 mm or more, the cost of the preform 23 can be reduced. In addition, by making the thickness T14 of the inner layer 24 1.95 mm or less, the plastic bottle 10 produced from the preform 23 can be made thin-walled.

(Outer layer of preform)
Next, a description will be given of the outer layer 25 of the preform 23. As shown in Fig. 10, the outer layer 25 is provided from the lower part of the mouth portion 26 (approximately the center part in the vertical direction of the support ring 26c) to the bottom portion 28.

In this embodiment, the entire inner surface of the outer layer 25 is covered with the inner layer 24. This reduces the cost of the preform 23.

The material constituting the outer layer 25 is the same as the material constituting the outer layer 12 of the plastic bottle 10. That is, the outer layer 25 of the preform 23 contains polyethylene furanoate.

It is preferable that the thickness (radial distance) of the outer layer 25 is equal to or greater than the thickness (radial distance) of the inner layer 24 in any region where the inner layer 24 is provided. This effectively improves the gas barrier properties, aroma retention, whitening resistance, and dimensional stability of the plastic bottle 10 produced from the preform 23.

In the illustrated example, the outer layer 25 is configured so that the thickness (t11 to t13 (radial distance)) changes in the body 27 of the preform 23. However, the outer layer 25 may have a substantially constant thickness (t11 to t13) in the body 27 of the preform 23. In the illustrated example, the thickness t11 of the outer layer 25 is substantially constant in the large diameter portion 27a. On the other hand, the thickness t12 of the outer layer 25 gradually becomes thinner toward the top in the reduced diameter portion 27c. In addition, the thickness t13 of the outer layer 25 gradually becomes thinner toward the top near the upper end of the small diameter portion 27b, but the thickness t13 of the outer layer 25 is substantially constant in the portions other than the upper end of the small diameter portion 27b. In addition, the thickness t14 of the outer layer 25 is substantially constant in the bottom portion 28.

Here, in the large diameter portion 27a, the thickness t11 of the outer layer 25 is preferably 0.5 to 2.0 times the thickness T11 of the inner layer 24. In this case, the thickness t11 of the outer layer 25 and the thickness T11 of the inner layer 24 in the large diameter portion 27a are measured at a position 1.5 mm from the bottom surface of the support ring 26c in the large diameter portion 27a. In addition, in the reduced diameter portion 27c, the thickness t12 of the outer layer 25 is preferably 0.5 to 2.0 times the thickness T12 of the inner layer 24. In this case, the thickness t12 of the outer layer 25 and the thickness T12 of the inner layer 24 in the reduced diameter portion 27c are measured at a position 8.0 mm from the bottom surface of the support ring 26c in the reduced diameter portion 27c. Furthermore, in the small diameter portion 27b, the thickness t13 of the outer layer 25 is preferably 0.5 to 2.0 times the thickness T13 of the inner layer 24. In this case, the thickness t13 of the outer layer 25 and the thickness T13 of the inner layer 24 in the small diameter portion 27b are measured at a position 25 mm from the lower surface of the support ring 26c in the small diameter portion 27b. In this way, the thickness t11 of the outer layer 25 is 0.5 times or more the thickness T11 of the inner layer 24, the thickness t12 of the outer layer 25 is 0.5 times or more the thickness T12 of the inner layer 24, and the thickness t13 of the outer layer 25 is 0.5 times or more the thickness T13 of the inner layer 24, so that the amount of polyethylene furanoate used in the preform 23 can be increased. Therefore, the gas barrier property of the plastic bottle 10 produced from the preform 23 can be improved. In addition, the thickness t11 of the outer layer 25 is 2.0 times or less than the thickness T11 of the inner layer 24, the thickness t12 of the outer layer 25 is 2.0 times or less than the thickness T12 of the inner layer 24, and the thickness t13 of the outer layer 25 is 2.0 times or less than the thickness T13 of the inner layer 24, thereby reducing the cost of the preform 23. In addition, the ratio of the thicknesses t11 to t13 of the outer layer 25 to the thicknesses T11 to T13 of the inner layer 24 can be prevented from becoming too large, so the plastic bottle 10 produced from the preform 23 can be made thin-walled.

In addition, in the bottom 28, the thickness t14 of the outer layer 25 is preferably 0.5 to 2.0 times the thickness T14 of the inner layer 24. In this way, by making the thickness t14 of the outer layer 25 0.5 times or more the thickness T14 of the inner layer 24, the amount of polyethylene furanoate used in the preform 23 can be increased. Therefore, the gas barrier properties of the plastic bottle 10 made from the preform 23 can be improved. In addition, by making the thickness t14 of the outer layer 25 2.0 times or less the thickness T14 of the inner layer 24, the cost of the preform 23 can be reduced. In addition, since the ratio of the thickness t14 of the outer layer 25 to the thickness T14 of the inner layer 24 can be prevented from becoming too large, the plastic bottle 10 made from the preform 23 can be made thin-walled.

As described above, according to this embodiment, the body 27 and bottom 28 of the preform 23 include the outer layer 25, and the mouth 26, body 27, and bottom 28 of the preform 23 include the inner layer 24 located inside the outer layer 25. The outer layer 25 also includes polyethylene furanoate. This allows high gas barrier properties to be maintained after blow molding of the preform 23. This allows the gas barrier properties of the plastic bottle 10 made from the preform 23 to be improved. In addition, the increased gas barrier properties of the plastic bottle 10 allow the aroma retention of the plastic bottle 10 to be improved. This allows the aroma of the contents filled in the plastic bottle 10 to be retained for a long period of time. Furthermore, the outer layer 25 includes polyethylene furanoate, which allows the whitening resistance and dimensional stability of the plastic bottle 10 made from the preform 23 to be improved.

The inner layer 24 also contains virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. This makes it possible to reduce the cost of the plastic bottle 10 produced from the preform 23. The inner layer 24 also contains virgin polyester, biomass-derived polyester, or chemically recycled polyester, making it possible to improve the hygiene of the plastic bottle 10. The inner layer 24 also contains biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester, making it possible to reduce the environmental impact of the plastic bottle 10.

In addition, according to this embodiment, the mouth portion 26 of the preform 23 has a support ring 26c. At least a portion of the support ring 26c includes an outer layer 25. This can further improve the gas barrier properties of the plastic bottle 10 produced from the preform 23.

Furthermore, according to this embodiment, the entire inner surface of the outer layer 25 is covered by the inner layer 24. This makes it possible to reduce the cost of the plastic bottle 10 produced from the preform 23. Also, because the entire inner surface of the outer layer 12 is covered by the inner layer 11, the area that comes into contact with the contents can be covered by the inner layer 11. Therefore, when the inner layer 11 contains virgin polyester, biomass-derived polyester, or chemically recycled polyester, the hygiene of the plastic bottle 10 can be further improved.

The components disclosed in each of the above embodiments and modifications may be combined as needed. Alternatively, some components may be deleted from all the components shown in each of the above embodiments and modifications.

REFERENCE SIGNS LIST 10 Plastic bottle 11 Inner layer 12 Outer layer 13 Mouth portion 16 Body portion 17 Bottom portion 23 Preform 24 Inner layer 25 Outer layer 26 Mouth portion 26c Support ring 27 Body portion 27a Large diameter portion 27b Small diameter portion 27c Reduced diameter portion 28 Bottom portion

Claims (12)

The mouth part,
A body portion connected to the mouth portion;
a bottom portion connected to the body portion,
the mouth, the body and the base each include an outer layer;
The body and the base include an inner layer positioned inside the outer layer,
The outer layer comprises virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester;
The preform, wherein the inner layer comprises polyethylene furanoate. The preform according to claim 1, wherein the body has a large diameter portion located on the mouth side, a small diameter portion located on the bottom side, and a tapered portion located between the large diameter portion and the small diameter portion and tapering from the large diameter portion side toward the small diameter portion side. The preform according to claim 2, wherein in the large diameter section, the thickness of the inner layer is 0.2 to 2.0 times the thickness of the outer layer, in the reduced diameter section, the thickness of the inner layer is 0.33 to 2.0 times the thickness of the outer layer, and in the small diameter section, the thickness of the inner layer is 0.33 to 2.0 times the thickness of the outer layer. The preform according to claim 1, wherein the mouth portion has a support ring, and at least a portion of the support ring includes the inner layer. The mouth part,
A body portion connected to the mouth portion;
a bottom portion connected to the body portion,
the body and the base include an outer layer;
the mouth portion, the body portion and the bottom portion each include an inner layer located inside the outer layer,
the outer layer comprises polyethylene furanoate;
The preform, wherein the inner layer comprises virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. The preform according to claim 5, wherein the body has a large diameter portion located on the mouth side, a small diameter portion located on the bottom side, and a tapered portion located between the large diameter portion and the small diameter portion and tapering from the large diameter portion side to the small diameter portion side. The preform according to claim 6, wherein the thickness of the outer layer in the large diameter section is 0.5 to 2.0 times the thickness of the inner layer, the thickness of the outer layer in the reduced diameter section is 0.5 to 2.0 times the thickness of the inner layer, and the thickness of the outer layer in the small diameter section is 0.5 to 2.0 times the thickness of the inner layer. The preform according to claim 5, wherein the mouth portion has a support ring, and at least a portion of the support ring includes the outer layer. The preform according to claim 5, wherein the inner surface of the outer layer is entirely covered by the inner layer. The mouth part,
A body portion connected to the mouth portion;
a bottom portion connected to the body portion,
the mouth, the body and the base each include an outer layer;
The body and the base include an inner layer positioned inside the outer layer,
The outer layer comprises virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester;
The plastic bottle, wherein the inner layer comprises polyethylene furanoate. The mouth part,
A body portion connected to the mouth portion;
a bottom portion connected to the body portion,
the body and the base include an outer layer;
the mouth portion, the body portion and the bottom portion each include an inner layer positioned inside the outer layer,
the outer layer comprises polyethylene furanoate;
The plastic bottle, wherein the inner layer comprises virgin polyester, biomass-derived polyester, mechanically recycled polyester, or chemically recycled polyester. A method for manufacturing a plastic bottle, comprising:
Providing a preform according to any one of claims 1 to 9;
heating the preform;
and a step of subjecting the preform to biaxial stretch blow molding.

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