Preform and method for manufacturing the same, and plastic bottle and method for manufacturing the same

Abstract

To provide a preform whose blow molding can be easily performed, and a method for manufacturing the preform, and a plastic bottle and a method for manufacturing the bottle.SOLUTION: A preform 10 having an inner layer member 40 and an outer layer member 50 comprises: a mouth plug part 11 having a thread part 13, a neck part 17 positioned below the thread part 13, a support ring 14 positioned below the neck part 17, and an annular groove part 18 formed on an external surface between the neck part 17 and the support ring 14; and a preform body 25 connected to the mouth plug part 11. The thread part 13 and the neck part 17 are formed on the inner layer member 40, the support ring 14 is formed on the outer layer member 50, and the preform body 25 is formed of both of the inner layer member 40 and the outer layer member 50. A border line BL between the inner layer member 40 and the outer layer member 50 is positioned on the annular groove part 18.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a preform and a method for manufacturing the same, and a plastic bottle and a method for manufacturing the same. [Background technology]

[0002] Recently, plastic bottles have become common for containing liquid contents such as food and beverages. Plastic bottles are manufactured by inserting a preform into a mold and subjecting it to biaxial stretch blow molding.

[0003] Such preforms include those containing two types of materials, an outer layer member and an inner layer member. Two-color molding is known as a method for producing a preform containing two types of materials. However, when using the two-color molding method, a two-color molding machine must be used, which poses a problem of high equipment costs.

[0004] Also known is a preform consisting of two layers, an outer layer and an inner layer, produced by injection molding (Patent Document 1). However, if the male thread portion is on the outer layer side, it may be difficult to use recycled resin for the outer layer, for example, for hygiene reasons. On the other hand, if the neck ring is on the inner layer side, there is a risk that the outer layer will fall off from the inner layer during blow molding.

[0005] Furthermore, in the preform of Patent Document 1, an intermediate layer is provided between the outer layer body and the inner layer body, and these are integrated. However, when inserting the inner layer body into the outer layer body, if the dimensional difference (gap) between the outer layer body and the inner layer body is large, the intermediate layer is likely to come off after they are integrated. Conversely, if the dimensional difference (gap) between the outer layer body and the inner layer body is small, it is difficult to insert the inner layer body into the outer layer body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-42995 Summary of the Invention [Problem to be solved by the invention]

[0007] The present embodiment provides a preform and a method for manufacturing the same, and a plastic bottle and a method for manufacturing the same, which are easy to perform blow molding. [Means for solving the problem]

[0008] The embodiments of the present disclosure relate to the following [1] to

[12] .

[0009] [1] A preform having an inner layer member and an outer layer member, comprising: a threaded portion, a cap located below the threaded portion, a support ring located below the cap, and a stopper portion having an annular groove formed on the outer surface between the cap and the support ring; and a preform body connected to the stopper portion, wherein the threaded portion and the cap are formed in the inner layer member, the support ring is formed in the outer layer member, the preform body is formed from both the inner layer member and the outer layer member, and the boundary line between the inner layer member and the outer layer member is located in the annular groove.

[0010] [2] The preform according to [1], wherein the boundary line is located at the lower end of the annular groove portion.

[0011] [3] The annular groove portion is formed in the inner layer member, the inner layer member has a step portion recessed radially inward from the annular groove portion, and the upper end of the outer layer member is accommodated in the step portion of the inner layer member. [1] or [2] A preform described in

[0012] [4] A preform according to any one of [1] to [3], wherein the main material of the inner layer member is polyethylene terephthalate and the main material of the outer layer member is polypropylene.

[0013] [5] A preform according to any one of [1] to [3], wherein the main material of the inner layer member is cycloolefin polymer, and the main material of the outer layer member is polyethylene terephthalate.

[0014] [6] A preform according to any one of [1] to [3], wherein the main material of the inner layer member is virgin polyester or chemically recycled polyester, and the main material of the outer layer member is mechanically recycled polyester.

[0015] [7] A preform having an inner layer member and an outer layer member, comprising: a stopper portion having an annular convex portion, a support ring located below the annular convex portion, and an annular groove portion formed on the outer surface between the annular convex portion and the support ring; and a preform body connected to the stopper portion, wherein the annular convex portion is formed on the inner layer member, the support ring is formed on the outer layer member, the preform body is formed from both the inner layer member and the outer layer member, and the boundary line between the inner layer member and the outer layer member is located at the annular groove portion.

[0016] [8] A plastic bottle having an inner layer member and an outer layer member, comprising: a spout portion having a threaded portion, a cap located below the threaded portion, a support ring located below the cap, and an annular groove formed on the outer surface between the cap and the support ring; and a bottle body connected to the spout portion, wherein the threaded portion and the cap are formed on the inner layer member, the support ring is formed on the outer layer member, the bottle body is formed from both the inner layer member and the outer layer member, and the boundary line between the inner layer member and the outer layer member is located at the annular groove.

[0017] [9] A plastic bottle having an inner layer member and an outer layer member, comprising: a spout portion having an annular convex portion, a support ring located below the annular convex portion, and an annular groove portion formed on the outer surface between the annular convex portion and the support ring; and a bottle body connected to the spout portion, wherein the annular convex portion is formed on the inner layer member, the support ring is formed on the outer layer member, the bottle body is formed from both the inner layer member and the outer layer member, and the boundary line between the inner layer member and the outer layer member is located at the annular groove portion.

[0018]

[10] A method for manufacturing a preform according to any one of [1] to [7], comprising the steps of preparing the inner layer member and the outer layer member, and inserting the inner layer member inside the outer layer member.

[0019]

[11] A method for manufacturing a preform according to

[10] , wherein in the step of inserting the inner layer member inside the outer layer member, the temperature of the outer layer member is made higher than the temperature of the inner layer member.

[0020]

[12] A method for manufacturing a plastic bottle, comprising the steps of preparing a preform according to any one of [1] to [7], and blow molding the preform. [Effects of the Invention]

[0021] According to embodiments of the present disclosure, preforms are easy to blow mold. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a front view showing a preform according to a first embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view showing a preform according to the first embodiment. [Figure 3] FIG. 3 is a vertical cross-sectional view showing an inner layer member of the preform according to the first embodiment. [Figure 4]FIG. 4 is a vertical cross-sectional view showing an outer layer member of the preform according to the first embodiment. [Figure 5] FIG. 5 is a vertical cross-sectional view showing the plastic bottle according to the first embodiment. [Figure 6] 6(a) and 6(b) are vertical cross-sectional views showing a method for manufacturing a preform according to the first embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a preform in a blow mold. [Figure 8] FIG. 8 is a vertical cross-sectional view showing a preform according to a modified example of the first embodiment. [Figure 9] FIG. 9 is a vertical cross-sectional view showing a preform according to a second embodiment. [Figure 10] FIG. 10 is a vertical cross-sectional view showing an inner layer member of a preform according to a second embodiment. [Figure 11] FIG. 11 is a vertical cross-sectional view showing an outer layer member of a preform according to a second embodiment. [Figure 12] FIG. 12 is a vertical cross-sectional view showing a plastic bottle according to a second embodiment. [Figure 13] FIG. 13 is a vertical cross-sectional view showing a preform according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the actual objects have been appropriately changed and exaggerated for the sake of ease of illustration and understanding.

[0024] (First embodiment) A first embodiment will be described with reference to FIGS. 1 to 8. FIGS. 1 to 8 are diagrams illustrating the first embodiment. The following figures are schematic diagrams. Therefore, the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, appropriate modifications can be made within the scope of the technical concept. In the following figures, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted. The numerical values, such as dimensions, and material names of each member described in this specification are examples of an embodiment and are not limited to these and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are interpreted not only strictly but also to include substantially the same state.

[0025] In this specification, "upper" and "lower" refer to the upper and lower sides in a state in which the mouth portion 11 of the preform 10 faces vertically upward and the bottom portion 30 of the preform 10 faces vertically downward (FIGS. 1 and 2). In this specification, the "central axis CL" of the preform 10 refers to the central axis of the cylinder that forms the inner surface of the mouth portion 11 of the preform 10. The same applies to the plastic bottle 60 (FIG. 5).

[0026] In this specification, the "height direction" refers to the direction along the central axis CL of the preform 10, and the "radial direction" refers to the direction perpendicular to the central axis CL of the preform 10. The "circumferential direction" refers to the circumferential direction of a circle centered on the central axis CL of the preform 10. The "horizontal cross section" refers to a cross section cut along a plane perpendicular to the central axis CL of the preform 10. The "vertical cross section" refers to a cross section cut along a plane including the central axis CL of the preform 10. The same applies to the plastic bottle 60 (FIG. 5).

[0027] (preform) An outline of the preform according to this embodiment will be described with reference to FIGS.

[0028] The preform 10 shown in Fig. 1 includes a mouth portion 11 and a preform body 25 connected to the mouth portion 11. As shown in Fig. 2, the preform 10 has an inner layer member 40 and an outer layer member 50. The outer layer member 50 is located radially outward of the inner layer member 40, at least in the region of the preform body 25. The inner layer member 40 and the outer layer member 50 are produced as separate bodies and then integrated with each other.

[0029] The plug portion 11 has an opening 16, a mouth body 12, a threaded portion 13, a cap 17, an annular groove 18, and a support ring 14. The threaded portion 13 is located below the opening 16. The cap 17 is located below the threaded portion 13. The support ring 14 is located below the cap 17. The annular groove 18 is formed on the outer surface between the cap 17 and the support ring 14.

[0030] The threaded portion 13 and the cover 17 are formed in the inner layer member 40. The support ring 14 is formed in the outer layer member 50. The preform body 25 is formed from both the inner layer member 40 and the outer layer member 50. The boundary line BL between the inner layer member 40 and the outer layer member 50 is located in the annular groove portion 18.

[0031] The preform body 25 includes a trunk portion 20 and a bottom portion 30 connected to the trunk portion 20. The trunk portion 20 has a large diameter portion 21, a small diameter portion 23, and a tapered diameter portion 22. The large diameter portion 21 is located on the spout portion 11 side. The small diameter portion 23 is located on the bottom portion 30 side. The tapered diameter portion 22 is located between the large diameter portion 21 and the small diameter portion 23. At least the inner surface of the tapered diameter portion 22 tapers in diameter from the large diameter portion 21 side toward the small diameter portion 23 side.

[0032] The preform 10 according to this embodiment will now be described in further detail.

[0033] The mouth portion 11 is located above the preform body 25. As described above, the mouth portion 11 has the opening 16, the mouth body 12, the threaded portion 13, the turnip 17, the annular groove 18, and the support ring 14. Of the mouth portion 11, the opening 16, the mouth body 12, the threaded portion 13, the turnip 17, and the annular groove 18 are composed of an inner layer member 40.

[0034] A cap (not shown) is attached to the spout 11. The cap has a peel ring that is peeled off when the cap is opened. When the cap is removed and opened, the peel ring of the cap comes into contact with the cap tab 17 of the spout 11 and peels off from the cap. The peel ring falls into the annular groove 18 and is held on the support ring 14.

[0035] The mouth body 12 is a generally cylindrical member. An opening 16 is formed at one end of the mouth body 12. The other end of the mouth body 12 is connected to the preform body 25.

[0036] The threaded portion 13 is provided on the outer periphery of the neck body 12. The threaded portion 13 is used to screw on a cap (not shown) after the preform 10 is biaxially stretch-blow molded to produce a plastic bottle 60 (see FIG. 5). The threaded portion 13 is preferably a single-start thread, but may also be a double-start or triple-start thread. The threaded portion 13 has a vent slot 13a formed parallel to the central axis CL of the preform 10. The vent slot 13a serves to release internal pressure when the plastic bottle 60 is opened if a carbonated beverage is filled as the liquid to be filled, or if the liquid goes bad and the internal pressure increases. Therefore, if a non-carbonated liquid, such as water, is used as the liquid to be filled, the vent slot 13a is not necessarily provided.

[0037] The cap 17 is provided on the outer periphery of the mouth body 12. The cap 17 may also be called a lock ring. The cap 17 has an inclined surface 17a that the peeling ring rides over when the cap (not shown) is attached. The outer diameter of the cap 17 may be 25 mm or more and 32 mm or less. The height of the cap 17 may be 1.2 mm or more and 2.0 mm or less. The outer diameter of the cap 17 is smaller than the outer diameter of the support ring 14.

[0038] The annular groove 18 is provided on the outer periphery of the neck body 12. The annular groove 18 may also be referred to as below the cap, below the lock ring, or bead. The annular groove 18 is located between the cap 17 and the support ring 14. The annular groove 18 may be located directly below the cap 17. The annular groove 18 may be located directly above the support ring 14. The annular groove 18 is formed around the entire circumference of the neck 11. The outer diameter of the annular groove 18 is uniform in the vertical direction along the central axis CL of the preform 10. The outer diameter of the annular groove 18 may be 24 mm or more and 27 mm or less. The outer diameter of the annular groove 18 is smaller than the outer diameter of the cap 17.

[0039] A boundary line BL between the inner layer member 40 and the outer layer member 50 is located in the annular groove portion 18. The boundary line BL is formed in a circular shape around the entire circumference of the annular groove portion 18. The annular groove portion 18 is formed in the inner layer member 40. Specifically, the inner layer member 40 has a step portion 44 that is recessed radially inward from the annular groove portion 18. The outer layer member 50 has an upper end 55 that corresponds to the upper part of the support ring 14. The upper end 55 of the outer layer member 50 is received in the step portion 44 of the inner layer member 40, thereby integrating the outer layer member 50 and the inner layer member 40. The annular groove portion 18 may be composed of both the inner layer member 40 and the outer layer member 50, or it may be composed of the outer layer member 50.

[0040] 2, the boundary line BL is located at the lower end of the annular groove 18. This allows the entire annular groove 18 to be made from the inner layer member 40. Therefore, when virgin polyester or the like is used as the main material of the inner layer member 40 for hygienic reasons, the annular groove 18, which may come into contact with the user's mouth, can also be made from virgin polyester or the like, making it hygienic. However, without being limited to this, the boundary line BL may be located between the upper and lower ends of the annular groove 18, or may be located at the upper end of the annular groove 18.

[0041] The support ring 14 is located below the plug portion 11 and is provided below the threaded portion 13, the turnip 17, and the annular groove portion 18. The support ring 14 has a flange-like shape. The support ring 14 protrudes in an annular shape around the entire circumference. The body portion 20 is connected below the support ring 14. During biaxial stretch blow molding, a heated preform 10 is inserted into a blow molding die 80 (FIG. 7), and the preform 10 is expanded from the inside by a stretch rod 84 of the blow molding machine and air pressure. At this time, the support ring 14 serves to prevent the preform 10 from slipping into the blow molding die 80.

[0042] The support ring 14 has an inclined surface 14a located on the annular groove portion 18 side and a bottom surface 14b located on the preform body 25 side. The bottom surface 14b contacts the blow molding die 80 during blow molding. The bottom surface 14b is located on a plane perpendicular to the central axis CL of the preform 10. The outer diameter of the support ring 14 may be 30 mm or more and 36 mm or less. The length of the support ring 14 in the height direction may be 1.8 mm or more and 3.0 mm or less.

[0043] As described above, the body portion 20 has the large diameter portion 21, the reduced diameter portion 22, and the small diameter portion .

[0044] The large diameter portion 21 is connected to the lower part of the support ring 14. The large diameter portion 21 has a generally cylindrical shape. The outer diameter of the large diameter portion 21 is different from the outer diameter of the annular groove portion 18 described above, but may be the same as the outer diameter of the annular groove portion 18. The inner diameter of the large diameter portion 21 may be the same as the inner diameter of the annular groove portion 18 described above, or may be smaller than the inner diameter of the annular groove portion 18 due to a draft gradient or the like.

[0045] The reduced diameter portion 22 is connected to the lower part of the large diameter portion 21. At least the inner surface of the reduced diameter portion 22 gradually reduces in diameter from the large diameter portion 21 side toward the small diameter portion 23 side. The outer surface of the reduced diameter portion 22 may also gradually reduce in diameter from the large diameter portion 21 side toward the small diameter portion 23 side. At least the inner surface of the reduced diameter portion 22 has an outer diameter that changes along the height direction. The inner diameter of the reduced diameter portion 22 gradually becomes thinner from the large diameter portion 21 side toward the small diameter portion 23 side.

[0046] The small diameter portion 23 is connected to the lower part of the reduced diameter portion 22. The horizontal cross section of the small diameter portion 23 is circular throughout the height direction. The outer diameter of the small diameter portion 23 may vary along the height direction or may be constant along the height direction. The inner diameter of the small diameter portion 23 may vary along the height direction or may be constant along the height direction.

[0047] The bottom portion 30 is connected to the lower part of the small diameter portion 23. The bottom portion 30 may be hemispherical. The radii of curvature of the semicircles constituting the inner and outer surfaces of the bottom portion 30 may be uniform throughout the entire bottom portion 30, or may vary partway along the bottom portion 30.

[0048] The large diameter portion 21, the reduced diameter portion 22, and the small diameter portion 23 of the body portion 20 are composed of both the inner layer member 40 and the outer layer member 50. Similarly, the bottom portion 30 is composed of both the inner layer member 40 and the outer layer member 50.

[0049] Next, the outer layer member 50 and the inner layer member 40 of the preform 10 will be described in more detail.

[0050] As shown in FIG. 2 , the outer layer member 50 is disposed around the entire circumferential area of ​​the inner layer member 40 so as to surround it. The outer layer member 50 and the inner layer member 40 are fixed in contact with each other. In other words, the outer layer member 50 is fixed to the outer surface of the inner layer member 40 without being welded or bonded. Here, "welded" refers to at least one of the outer layer member 50 and the inner layer member 40 partially melting and adhering to the other. "Bonded" refers to the outer layer member 50 and the inner layer member 40 being attached to each other via another member such as an adhesive. The outer layer member 50 and the inner layer member 40 may be fixed to each other by their respective temperature differences. For example, the outer layer member 50 may be heated to a higher temperature than the inner layer member 40 to cause thermal expansion. In this state, the outer layer member 50 may be disposed around the inner layer member 40, and then the temperature of the outer layer member 50 may be lowered, causing the outer layer member 50 to thermally shrink and fix the outer layer member 50 to the periphery of the inner layer member 40. In this case, the outer layer member 50 can be removed from the inner layer member 40 by again heating the outer layer member 50 to a higher temperature than the inner layer member 40 and causing thermal expansion.

[0051] (Inner layer material) Next, the inner layer member 40 will be described with reference to FIG. 3. The inner layer member 40 is manufactured by, for example, injection molding or compression molding. The inner layer member 40 includes the opening 16, the neck body 12, the threaded portion 13, and the cap 17. The inner layer member 40 may include the entire annular groove portion 18, or may include only a portion of the annular groove portion 18. The inner layer member 40 further includes a body inner layer member 41 and a bottom inner layer member 42. The body inner layer member 41 constitutes the inner layer of the body portion 20 of the preform 10. The bottom inner layer member 42 constitutes the inner layer of the bottom portion 30 of the preform 10. When the inner layer member 40 is manufactured by injection molding, an inner layer gate protrusion 43 is formed on the lowest part of the outer surface of the bottom inner layer member 42 (the part farthest from the opening 16).

[0052] The thickness T1 of the body inner layer member 41 may be 0.8 mm or more, 1.2 mm or more, or 1.8 mm or more. The thickness T1 of the body inner layer member 41 may be 4.0 mm or less, 2.8 mm or less, or 2.2 mm or less. The thickness T1 of the body inner layer member 41 is the thickness at the thickest point of the body inner layer member 41, and refers to the length in the direction perpendicular to the central axis CL.

[0053] The main material of the inner layer member 40 is preferably a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), COP (cycloolefin polymer), etc. Plant-derived biomass plastics, such as PLA (polylactic acid), can also be used. Alternatively, a resin blend of the above-mentioned various resins may be used. In this specification, the term "main material" refers to a material that accounts for more than 50% by mass, preferably more than 80% by mass, of a given member.

[0054] The inner layer member 40 may contain virgin polyester or chemically recycled polyester (hereinafter simply referred to as virgin polyester, etc.). Herein, "virgin polyester" refers to polyester that has not been subjected to a recycling process, i.e., unused polyester. Also, in this specification, "chemically recycled polyester" refers to polyester obtained by decomposing polyester containers to the monomer level or to BHET (bis-2-hydroxyethyl terephthalate) and then repolymerizing it.

[0055] When the inner layer member 40 contains virgin polyester or the like, the content of virgin polyester or the like is preferably 20 parts by mass or more and 100 parts by mass or less, and more preferably 60 parts by mass or more and 90 parts by mass or less, per 100 parts by mass of the total amount of resin material contained in the inner layer member 40.

[0056] When the inner layer member 40 contains 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 refers to polyester produced using an antimony catalyst as a polymerization catalyst. Therefore, the polyesters listed above refer to polyesters produced using the respective catalysts as polymerization catalysts.

[0057] Examples of antimony catalysts include antimony trioxide, antimony pentoxide, antimony acetate, triphenylantimony, and antimony glycol.

[0058] Examples of the manganese catalyst include fatty acid manganese salts such as manganese acetate, manganese carbonate, manganese chloride, manganese acetylacetonate salts, and manganese hydroxide.

[0059] Examples of the titanium catalyst 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, titanate-aluminum hydroxide mixtures, titanium chloride, titanium chloride-aluminum chloride mixtures, titanium bromide, titanium fluoride, potassium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, and titanium acetylacetonate.

[0060] Examples of aluminum catalysts include aluminum trisacetylacetate, aluminum monoacetylacetonate bis(ethylacetoacetate), and ethylacetoacetate aluminum diisopropylate.

[0061] Examples of the lithium catalyst include ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, and phenyllithium.

[0062] Examples of germanium catalysts include germanium dioxide, germanium tetroxide, germanium tetramethoxide, germanium tetraethoxide, germanium tetrapropoxide, germanium tetrabutoxide, germanium tetrapentoxide, and germanium tetrahexoxide.

[0063] In this embodiment, the term "polyester" refers to a copolymer of a dicarboxylic acid compound and a diol compound.

[0064] 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.

[0065] 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.

[0066] Among polyesters, polyethylene terephthalate, which is a copolymer of terephthalic acid and ethylene glycol, or modified polyethylene terephthalate in which a copolymerization monomer is added to this is preferred.

[0067] The polyester may be biomass-derived polyethylene terephthalate or fossil fuel-derived polyethylene terephthalate. 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 inner layer member 40 contains biomass-derived polyethylene terephthalate, thereby improving the environmental impact reduction of the plastic bottle 60.

[0068] The polyester may contain a monomer other than the dicarboxylic acid compound and the diol compound as long as the properties of the present embodiment are not impaired. However, the content of such a monomer is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably 3 mol % or less, based on the total structural units.

[0069] The inner layer member 40 may contain mechanically recycled polyester. In this case, the environmental impact of the plastic bottle 60 can be reduced. In this specification, "mechanically recycled polyester" refers to polyester obtained by sorting, crushing, and washing polyester containers to remove contaminants and foreign matter, obtaining flakes, and then treating the flakes for a certain period of time under high temperature and reduced pressure to remove contaminants from within the resin. The mechanically recycled polyester may contain two or more catalysts. In this case, the mechanically recycled polyester may contain two or more of antimony-catalyzed polyester, manganese-catalyzed polyester, titanium-catalyzed polyester, aluminum-catalyzed polyester, lithium-catalyzed polyester, and germanium-catalyzed polyester, for example.

[0070] When the inner layer member 40 contains mechanically recycled polyester, the content of the mechanically recycled polyester is preferably 20 parts by mass or more and 100 parts by mass or less, and more preferably 60 parts by mass or more and 90 parts by mass or less, per 100 parts by mass of the total amount of resin material contained in the inner layer member 40.

[0071] The inner layer member 40 may contain additives, as long as they do not impair the properties of this embodiment. Examples of such 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, deodorizers, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, slip agents, mold release agents, antioxidants, ion exchange agents, acetaldehyde absorbers (for example, AA Scavengers manufactured by Color Matrix), and colorants.

[0072] (Outer layer material) Next, the outer layer member 50 will be described with reference to FIG. 4. The outer layer member 50 is manufactured by, for example, injection molding or compression molding. The outer layer member 50 includes a support ring 14. The outer layer member 50 does not include the annular groove portion 18, but may include all or part of the annular groove portion 18. The outer layer member 50 further includes a body outer layer member 51 and a bottom outer layer member 52. The body outer layer member 51 constitutes the outer layer of the body portion 20 of the preform 10. The bottom outer layer member 52 constitutes the outer layer of the bottom portion 30 of the preform 10. When the outer layer member 50 is manufactured by injection molding, an outer layer gate protrusion 53 is formed at the bottom of the outer surface of the bottom outer layer member 52 (the portion farthest from the opening 16). A gate accommodating recess 54 is formed at the bottom of the inner surface of the bottom outer layer member 52. When the outer layer member 50 and the inner layer member 40 are integrated together, the inner layer gate protrusion 43 (FIG. 3) of the inner layer member 40 is accommodated in the gate accommodating recess 54. This prevents a gap from being formed between the bottom outer layer member 52 and the bottom inner layer member 42.

[0073] The thickness T2 of the body outer layer member 51 may be 0.8 mm or more, 1.2 mm or more, or 1.8 mm or more. The thickness T2 of the body outer layer member 51 may be 4.0 mm or less, 2.8 mm or less, or 2.0 mm or less. The thickness T2 of the body outer layer member 51 is the thickness at the thickest point of the body outer layer member 51, and refers to the length in the direction perpendicular to the central axis CL.

[0074] The thickness T2 of the body outer layer member 51 may be the same as or different from the thickness T1 (FIG. 3) of the body inner layer member 41. The thickness T2 of the body outer layer member 51 may be 50% or more, 75% or more, or 100% or more of the thickness T1 (FIG. 3) of the body inner layer member 41. The thickness T2 of the body outer layer member 51 may be 200% or less, 150% or less, or 100% or less of the thickness T1 of the body inner layer member 41.

[0075] The main material of the outer layer member 50 may be any of the materials listed above as the main material of the inner layer member 40. The main material of the outer layer member 50 may be the same as or different from the main material of the inner layer member 40.

[0076] When the main material of the outer layer member 50 is different from the main material of the inner layer member 40, the main materials of the outer layer member 50 and the inner layer member 40 may be, for example, the following combinations of materials.

[0077] (1) Polyethylene terephthalate may be used as the main material for the inner layer member 40, and polypropylene may be used as the main material for the outer layer member 50. Polyethylene terephthalate has excellent oxygen barrier properties, and polypropylene has excellent water vapor barrier properties. Therefore, a plastic bottle 60 with excellent barrier properties for both can be obtained.

[0078] (2) Cycloolefin polymer may be used as the main material for the inner layer member 40, and polyethylene terephthalate may be used as the main material for the outer layer member 50. Cycloolefin polymer has excellent moisture resistance, chemical resistance, and low adsorption properties, but is expensive. For this reason, it is possible to make the container made of cycloolefin polymer lighter (thinner), but in this case, the strength of the container will be weakened. Therefore, by using polyethylene terephthalate as the main material for the outer layer member 50, the plastic bottle 60 can be made thick, and moisture resistance, chemical resistance, low adsorption, and container strength can all be achieved.

[0079] (3) Virgin polyester or chemically recycled polyester (virgin polyester, etc.) may be used as the main material for the inner layer member 40, and mechanically recycled polyester may be used as the main material for the outer layer member 50. In this case, since the main materials of the mouth body 12, the screw portion 13, the turnip 17, the body inner layer member 41, and the bottom inner layer member 42, which come into contact with the contents and the user's mouth, are virgin polyester, etc., high hygiene can be maintained.

[0080] (Plastic bottle) Next, an example of a plastic bottle produced by biaxially stretching and blow molding such a preform 10 will be described with reference to Figure 5. Of course, the plastic bottle produced using the above-described preform 10 is not limited to this. For example, the plastic bottle may be a petaloid bottle.

[0081] In Figure 5, a plastic bottle 60 includes a spout 61 and a bottle body 65. The bottle body 65 includes a neck 64, a shoulder 68, a substantially cylindrical body 62, and a bottom 63. The body 62 is located below the spout 61. The bottom 63 is provided contiguous with the bottom of the body 62. The neck 64 is located between the spout 61 and the body 62. The shoulder 68 is located between the neck 64 and the body 62.

[0082] The plug portion 61 corresponds to the plug portion 11 of the above-described preform 10. The configuration of the plug portion 61 is substantially the same as the configuration of the plug portion 11 of the preform 10, so a detailed description thereof will be omitted here.

[0083] The bottle body 65 corresponds to the preform body 25 of the preform 10 described above. The horizontal cross section of the body 62 of the bottle body 65 is generally circular, but may be generally polygonal or another shape. The neck 64 is generally cylindrical. The horizontal cross section of the shoulder 68 may be generally circular, or may be generally polygonal or another shape. The area of ​​the horizontal cross section of the shoulder 68 gradually increases from the neck 64 side toward the body 62 side.

[0084] A recess 66 is formed in the radial center of the bottom 63. A ground contact portion 67 is located around the recess 66. The ground contact portion 67 may be provided in an annular shape over the entire circumferential area of ​​the bottom 63, or the ground contact portion 67 may be divided into multiple portions like a petaloid bottom.

[0085] The size of such a plastic bottle 60 is not limited, and a bottle of any size may be used. The full capacity of the plastic bottle 60 may be, for example, 100 ml or more, 200 ml or more, or 300 ml or more. The full capacity of the plastic bottle 60 may be, for example, 2500 ml or less, 1500 ml or less, or 600 ml or less.

[0086] In this embodiment, the plastic bottle 60 has an inner layer member 40 and an outer layer member 50. The outer layer member 50 is located radially outward of the inner layer member 40, at least in the region of the bottle body 65. The threaded portion 13 and the cap 17 of the spout portion 61 are formed in the inner layer member 40. The support ring 14 is formed in the outer layer member 50. The bottle body 65 is formed from both the inner layer member 40 and the outer layer member 50. The boundary line BL between the inner layer member 40 and the outer layer member 50 is located in the annular groove portion 18.

[0087] (Preform manufacturing method) Next, a method for manufacturing the preform 10 according to this embodiment will be described.

[0088] First, the inner layer member 40 and the outer layer member 50 are prepared. In this case, the inner layer member 40 and the outer layer member 50 may be produced by injection molding using, for example, an injection molding machine (not shown). Specifically, thermoplastic resin pellets such as polyethylene terephthalate (PET) are placed in an injection molding machine (not shown), which heats and melts the pellets. The pellets then become molten plastic, which is injected into an injection mold and pressurized. After a predetermined time has passed, the molten plastic hardens within the injection mold. The injection mold is then separated, and the inner layer member 40 or the outer layer member 50 is removed from the injection mold. The inner layer member 40 and the outer layer member 50 may also be produced by various molding methods, such as compression molding, in addition to injection molding.

[0089] Next, the inner layer member 40 is inserted inside the outer layer member 50 (see FIG. 6(a)). At this time, the upper end 55 of the outer layer member 50 is received in the step portion 44 of the inner layer member 40, thereby integrating the outer layer member 50 and the inner layer member 40. In this way, the outer layer member 50 is fixed to the outside of the inner layer member 40 without being welded or bonded.

[0090] At this time, the outer layer member 50 may be thermally expanded by raising the temperature of the outer layer member 50 higher than the temperature of the inner layer member 40. Specifically, assume that the inner diameter of the outer layer member 50 near the support ring 14 is 23.4 mm at a temperature of 25°C and that the outer layer member 50 is made of polyethylene terephthalate. When the outer layer member 50 is heated to 50°C, the inner diameter of the outer layer member 50 increases by approximately 0.038 mm, as follows:

[0091] Inner diameter of outer layer member 50 at 25°C: 23.4 mm Material of outer layer member 50: PET (linear expansion coefficient 6.5 × 10 -5 / ℃) Temperature of outer layer member 50 before heating: 25°C Post-heating temperature of outer layer member 50: 50°C Expansion of the inner diameter of the outer layer member 50: 23.4 mm x 6.5 x 10 -5 / ℃ × (50℃ - 25℃) ≒ 0.038 mm

[0092] The material of the outer layer member 50 is polypropylene (coefficient of linear expansion 11×10 -5 / °C), the amount of expansion of the inner diameter of the outer layer member 50 is 0.064 mm. -5 / °C), the amount of expansion of the inner diameter of the outer layer member 50 is 0.041 mm.

[0093] In this way, the inner diameter of the outer layer member 50 becomes larger than the outer diameter of the inner layer member 40, creating a gap between the inner layer member 40 and the outer layer member 50. This makes it easier to insert the inner layer member 40 into the outer layer member 50. After the inner layer member 40 is inserted into the outer layer member 50, the inner layer member 40 and the outer layer member 50 become at the same temperature, so that the two have substantially the same dimensions and the gap disappears.

[0094] Furthermore, the inner diameter of the outer layer member 50 may be made smaller than the outer diameter of the inner layer member 40, for example, by about 0.02 mm. In this case, when the outer layer member 50 is heated, a gap is created between the inner layer member 40, making it easier to insert. Thereafter, when the inner layer member 40 and the outer layer member 50 reach the same temperature, an interference fit is formed, and the two are firmly integrated.

[0095] Note that one method for increasing the temperature of the outer layer member 50 is to heat it with a heater, for example. As another method, since the temperature of the outer layer member 50 is high immediately after injection molding, the inner layer member 40 may be inserted into the outer layer member 50 immediately after molding. In this way, the energy required to heat the outer layer member 50 can be reduced.

[0096] When inserting the inner layer member 40 inside the outer layer member 50, the inner layer member 40 may be cooled instead of heating the outer layer member 50. Alternatively, the outer layer member 50 may be heated and the inner layer member 40 may be cooled.

[0097] In this way, a preform 10 having an outer layer member 50 and an inner layer member 40 is obtained (see FIG. 6(b)).

[0098] (Plastic bottle manufacturing method) Next, a method for manufacturing a plastic bottle 60 using the preform 10 according to this embodiment will be described.

[0099] First, the preform 10 shown in FIGS. 1 and 2 is produced by, for example, the method shown in FIGS. 5(a) and 5(b).

[0100] Next, the preform 10 is heated by a heater of a blow molding machine (not shown). The heating temperature of the preform 10 may be, for example, 90°C to 130°C.

[0101] The heated preform 10 is placed in a blow molding die 80 (see FIG. 7). The blow molding die 80 includes a pair of body molds 81 and 82 that are separated from each other, and a bottom mold 83. Next, high-pressure air is supplied into the preform 10 from a stretch rod 84 inserted into the preform 10, and the stretch rod 84 is extended. This causes the preform 10 to be extended.

[0102] During this time, only the mouth portion 11 of the preform 10, including the support ring 14, is exposed to the outside of the blow molding die 80. In addition, the brim-shaped support ring 14 abuts against the surface of the blow molding die 80 so that the mouth portion 11 is fixed when the preform 10 is inflated with the stretch rod 84 and high-pressure air. In this embodiment, the support ring 14 is provided on the outer layer member 50 of the preform 10. This makes it possible to prevent the outer layer member 50 and the inner layer member 40 from separating when the preform 10 is blow molded. If the support ring 14 were provided on the inner layer member 40, there was a risk that the outer layer member 50 would separate from the inner layer member 40 when the preform 10 was inflated.

[0103] A plastic bottle 60 is obtained from the preform 10 by blow molding the preform 10 in the blow molding mold 80. During this process, the body molds 81 and 82 are heated to 30°C to 150°C, and the bottom mold 83 is cooled to 5°C to 25°C. During this process, the preform 10 is expanded in the blow molding mold 80 and shaped into a shape corresponding to the inner surface of the blow molding mold 80. The pair of body molds 81 and 82 and the bottom mold 83 then move away from each other, and the plastic bottle 60 is removed from the blow molding mold 80. In this manner, the plastic bottle 60 shown in FIG. 5 is obtained.

[0104] As described above, according to this embodiment, the support ring 14 is formed on the outer layer member 50, and the boundary line BL between the inner layer member 40 and the outer layer member 50 is located in the annular groove portion 18. This makes it possible to prevent the outer layer member 50 and the inner layer member 40 from separating from each other when the preform 10 is inflated using the stretch rod 84 and high-pressure air during blow molding.

[0105] It is also conceivable to use virgin polyester or the like as the main material for the inner layer member 40, and mechanically recycled polyester as the main material for the outer layer member 50. According to this embodiment, the threaded portion 13 and the turnip 17 are formed in the inner layer member 40, and the preform body 25 (bottle body 65) is formed from both the inner layer member 40 and the outer layer member 50. As a result, the main materials of the spout body 12, the threaded portion 13, and the turnip 17, which come into contact with the contents and the user's mouth, are virgin polyester or the like, thereby maintaining high hygiene.

[0106] (Variation) Figure 8 shows a preform 10A according to a modified example of this embodiment. The preform 10A shown in Figure 8 has a different shape for the plug portion 11A, but other configurations are the same as those shown in Figures 1 to 7. In Figure 8, the same parts as those shown in Figures 1 to 7 are given the same reference numerals, and detailed explanations will be omitted.

[0107] 8, the preform 10A includes a mouth portion 11A and a preform body 25 connected to the mouth portion 11A. The preform 10A has an inner layer member 40 and an outer layer member 50. The outer layer member 50 is located radially outward of the inner layer member 40, at least in the region of the preform body 25. The inner layer member 40 and the outer layer member 50 are produced as separate bodies and then integrated with each other.

[0108] The spout 11A has an opening 16A, a spout body 12A, an annular protrusion 16B, an annular groove 18A, and a support ring 14. The annular protrusion 16B is formed around the entire outer periphery of the opening 16. The support ring 14 is located below the annular protrusion 16B. The annular groove 18A is formed on the outer surface between the annular protrusion 16B and the support ring 14.

[0109] Of the spout portion 11A, the opening 16A, annular convex portion 16B, neck portion main body 12A, and annular groove portion 18A are formed in the inner layer member 40. The support ring 14A is formed in the outer layer member 50. The preform body 25 is formed from both the inner layer member 40 and the outer layer member 50. The boundary line BL between the inner layer member 40 and the outer layer member 50 is located at the annular groove portion 18A.

[0110] (Second embodiment) Next, a second embodiment will be described with reference to Figures 9 to 13. Figures 9 to 13 are diagrams showing the second embodiment. The second embodiment shown in Figures 9 to 13 differs mainly in that an intermediate layer 70 is provided between an inner layer member 40 and an outer layer member 50, but other configurations are substantially the same as those of the first embodiment described above. In Figures 9 to 13, parts that are the same as those of the first embodiment shown in Figures 1 to 8 are given the same reference numerals, and detailed description thereof will be omitted.

[0111] (preform) An outline of the preform according to this embodiment will be described with reference to FIG.

[0112] The preform 10 shown in Fig. 9 includes a mouth portion 11 and a preform body 25 connected to the mouth portion 11. The preform 10 has an inner layer member 40, an outer layer member 50, and an intermediate layer 70. The outer layer member 50 is located radially outward of the inner layer member 40, at least in the region of the preform body 25. The intermediate layer 70 is located between the inner layer member 40 and the outer layer member 50, in the region of the preform body 25. The inner layer member 40, the outer layer member 50, and the intermediate layer 70 are produced as separate bodies and then integrated with each other.

[0113] The preform body 25 includes a body portion 20 and a bottom portion 30 connected to the body portion 20. The mouth portion 11 has an opening 16, a mouth body 12, a threaded portion 13, a cap 17, an annular groove 18, and a support ring 14. The threaded portion 13 is located below the opening 16. The cap 17 is located below the threaded portion 13. The support ring 14 is located below the cap 17. The annular groove 18 is formed on the outer surface between the cap 17 and the support ring 14.

[0114] The threaded portion 13, the turntable 17, and the annular groove portion 18 are formed in the inner layer member 40. The support ring 14 is formed in the outer layer member 50. The preform body 25 is formed from the inner layer member 40, the outer layer member 50, and the intermediate layer 70. The boundary line BL between the inner layer member 40 and the outer layer member 50 is located at the annular groove portion 18. The trunk portion 20 has a large diameter portion 21, a small diameter portion 23, and a reduced diameter portion 22.

[0115] The outer layer member 50 is provided over the entire circumferential area of ​​the inner layer member 40 so as to surround the inner layer member 40. In the area where the intermediate layer 70 is not provided, the outer layer member 50 and the inner layer member 40 are fixed in a state of contact with each other. The outer layer member 50 is fixed to the outer surface of the inner layer member 40 without being welded or bonded.

[0116] As shown in FIG. 10 , the inner layer member 40 includes an opening 16, a neck body 12, a threaded portion 13, a turnip 17, and an annular groove 18. The inner layer member 40 may include the entire annular groove 18, or may include only a portion of the annular groove 18. The inner layer member 40 further includes a body inner layer member 41 corresponding to the body portion 20, and a bottom inner layer member 42 corresponding to the bottom portion 30. The body inner layer member 41 constitutes the inner layer of the body portion 20 of the preform 10. The bottom inner layer member 42 constitutes the inner layer of the bottom portion 30 of the preform 10. An inner layer gate protrusion 43 is formed on the lowest portion (the portion farthest from the opening 16) of the outer surface of the bottom inner layer member 42.

[0117] An accommodating recess 46 for accommodating the intermediate layer 70 is formed in the region of the outer surface of the body inner layer member 41 corresponding to the body 20. The accommodating recess 46 is thinner than the region of the body inner layer member 41 adjacent to the accommodating recess 46. The accommodating recess 46 may be provided in a portion of the region corresponding to the small diameter portion 23, or may be provided in the entire region corresponding to the small diameter portion 23. An upper step 47 is formed at the upper end of the accommodating recess 46 (the end on the opening 16 side). The lower end of the accommodating recess 46 may be located at the upper end of the bottom inner layer member 42. A lower step (not shown) may be formed at the lower end of the accommodating recess 46.

[0118] The thickness T3 of the body inner layer member 41 at the installation recess 46 may be 0.8 mm or more, 1.2 mm or more, or 1.8 mm or more. The thickness T3 of the body inner layer member 41 at the installation recess 46 may be 4.0 mm or less, 2.8 mm or less, or 2.2 mm or less. The depth D1 of the installation recess 46 may be 0.015 mm or more, 0.05 mm or more, or 0.1 mm or more. The depth D1 of the installation recess 46 may be 0.9 mm or less, 0.5 mm or less, or 0.2 mm or less.

[0119] As shown in FIG. 11 , the outer layer member 50 includes a support ring 14. The outer layer member 50 does not include an annular groove portion 18, but may include all or part of the annular groove portion 18. The outer layer member 50 further includes a body outer layer member 51 and a bottom outer layer member 52. The body outer layer member 51 constitutes the outer layer of the body portion 20 of the preform 10. The bottom outer layer member 52 constitutes the outer layer of the bottom portion 30 of the preform 10. Although not shown, a receiving recess for receiving the intermediate layer 70 may be formed on the inner surface of the outer layer member 50. The configuration of the outer layer member 50 may be the same as the configuration of the outer layer member 50 of the preform 10 according to the first embodiment ( FIG. 4 ).

[0120] As shown in Figure 9, the intermediate layer 70 is located between the inner layer member 40 and the outer layer member 50. The intermediate layer 70 is located in the body portion 20. The intermediate layer 70 may be located in a portion of the small diameter portion 23, or in the entire small diameter portion 23. The intermediate layer 70 may be located in the reduced diameter portion 22, or in the large diameter portion 21. The intermediate layer 70 is wound around the inner layer member 40. The intermediate layer 70 is accommodated in the accommodation recess 46 of the body portion inner layer member 41. The inner surface of the intermediate layer 70 is in contact with the inner layer member 40. The outer surface of the intermediate layer 70 may be in contact with the outer layer member 50.

[0121] The intermediate layer 70 may be, for example, a film of ethylene vinyl alcohol copolymer (EVOH) or a film of MXD6. In this case, it is possible to improve the oxygen barrier properties of the preform 10. The intermediate layer 70 may be such a film wrapped around the inner layer member 40 in a cylindrical shape.

[0122] The intermediate layer 70 may be formed by applying a barrier resin material, such as a liquid polyvinyl alcohol resin, to the outer surface of the inner layer member 40 by dipping, brushing, spraying, or other methods, and then drying the applied material. Polyvinyl alcohol resin is a water-soluble or alkali-soluble resin, and has high cohesive strength, making it highly effective at blocking oxygen and water vapor. By including a polyvinyl alcohol resin in the intermediate layer 70, it is possible to form a water-soluble or alkali-soluble barrier layer and improve the gas barrier properties of the plastic bottle 60.

[0123] The thickness of the intermediate layer 70 may be 0.015 mm or more, 0.05 mm or more, or 0.1 mm or more. The thickness of the intermediate layer 70 may be 0.9 mm or less, 0.5 mm or less, or 0.2 mm or less.

[0124] The configuration of the preform 10 other than the above may be substantially the same as the configuration of the preform 10 according to the first embodiment.

[0125] (Plastic bottle) Next, referring to FIG. 12, an example of a plastic bottle produced by biaxially stretching and blow molding the preform 10 shown in FIG. 11 will be described.

[0126] 12, a plastic bottle 60 includes a spout 61 and a bottle body 65. The bottle body 65 includes a neck 64, a shoulder 68, a substantially cylindrical body 62, and a bottom 63.

[0127] 12, the plastic bottle 60 has an inner layer member 40, an outer layer member 50, and an intermediate layer 70. The intermediate layer 70 is located between the inner layer member 40 and the outer layer member 50. The intermediate layer 70 is provided on the body portion 62. However, the intermediate layer 70 may be provided on all or part of the neck portion 64, shoulder portion 68, body portion 62, and bottom portion 63.

[0128] The configuration of the plastic bottle 60 other than the intermediate layer 70 may be substantially the same as the configuration of the plastic bottle 60 according to the first embodiment.

[0129] (Preform manufacturing method) Next, a method for manufacturing the preform 10 according to this embodiment will be described.

[0130] First, the inner layer member 40 and the outer layer member 50 are prepared. Next, the intermediate layer 70 is provided around the inner layer member 40. When the intermediate layer 70 is a film, such a film may be wrapped around the inner layer member 40 in a cylindrical shape. Alternatively, when a barrier resin material such as a liquid polyvinyl alcohol resin is used as the intermediate layer 70, such a barrier resin material may be applied to the outer surface of the inner layer member 40 by a method such as dipping, brushing, or spraying, and then dried.

[0131] Next, the inner layer member 40 is inserted inside the outer layer member 50, thereby obtaining a preform 10 having the outer layer member 50 and the inner layer member 40.

[0132] The method for manufacturing the preform 10 other than the above may be substantially the same as the method for manufacturing the preform 10 according to the first embodiment.

[0133] (Plastic bottle manufacturing method) The method for manufacturing the plastic bottle 60 according to this embodiment may be substantially the same as that of the first embodiment.

[0134] According to this embodiment, an intermediate layer 70 is provided between the inner layer member 40 and the outer layer member 50. As a result, by using a material with high barrier properties against oxygen, water vapor, etc. as the intermediate layer 70, the barrier properties of the plastic bottle 60 against oxygen, water vapor, etc. can be improved.

[0135] (Variation) Figure 13 shows a preform 10A according to a modified example of the present embodiment. The preform 10A shown in Figure 13 differs in that an intermediate layer 70 is provided between the inner layer member 40 and the outer layer member 50, but other configurations are the same as the example shown in Figure 8. In Figure 13, the same parts as those in the embodiment shown in Figures 1 to 12 are given the same reference numerals, and detailed description thereof will be omitted.

[0136] 13, the preform 10A has an inner layer member 40, an outer layer member 50, and an intermediate layer 70. The intermediate layer 70 is located between the inner layer member 40 and the outer layer member 50 in the region of the preform body 25. The configuration of the intermediate layer 70 according to this modification may be the same as the configuration of the intermediate layer 70 shown in FIG.

[0137] The configuration of the preform 10A other than the intermediate layer 70 may be substantially the same as the configuration of the preform 10 shown in FIG.

[0138] The present disclosure is not limited to the above-described embodiments and modifications, and the components can be modified and embodied in practice without departing from the spirit of the present disclosure. Furthermore, various inventions can be created by appropriately combining multiple components disclosed in the above-described embodiments and modifications. Some components may be omitted from all the components shown in the embodiments and modifications. [Explanation of symbols]

[0139] 10 Preform 11 Spout part 12 Mouth body 13 Threaded section 14 Support ring 16 Opening 16B Annular convex part 17 Turnip 18 Annular groove 20 Torso 25 Preform body 30 bottom 40 Inner layer member 41 Body inner layer member 42 Bottom inner layer member 50 outer layer member 51 outer body member 52 Bottom outer layer member 60 plastic bottles

Claims

1. In a preform having an inner layer member and an outer layer member, a plug portion having a threaded portion, a cover located below the threaded portion, a support ring located below the cover, and an annular groove formed on the outer surface between the cover and the support ring; a preform body connected to the plug portion, The threaded portion and the turntable are formed on the inner layer member, The support ring is formed on the outer layer member, the preform body is formed from both the inner layer member and the outer layer member, a boundary line between the inner layer member and the outer layer member located in the annular groove portion.

2. The preform according to claim 1 , wherein the boundary line is located at a lower end of the annular groove.

3. The preform according to claim 1, wherein the annular groove is formed in the inner layer member, the inner layer member has a step recessed radially inward from the annular groove, and the upper end of the outer layer member is accommodated in the step of the inner layer member.

4. 2. The preform according to claim 1, wherein the main material of the inner layer member is polyethylene terephthalate, and the main material of the outer layer member is polypropylene.

5. 2. The preform according to claim 1, wherein the main material of the inner layer member is a cycloolefin polymer, and the main material of the outer layer member is polyethylene terephthalate.

6. 2. The preform according to claim 1, wherein the main material of the inner layer member is virgin polyester or chemically recycled polyester, and the main material of the outer layer member is mechanically recycled polyester.

7. In a preform having an inner layer member and an outer layer member, a plug portion having an annular protrusion, a support ring positioned below the annular protrusion, and an annular groove formed on an outer surface between the annular protrusion and the support ring; a preform body connected to the plug portion, The annular protrusion is formed on the inner layer member, The support ring is formed on the outer layer member, the preform body is formed from both the inner layer member and the outer layer member, a boundary line between the inner layer member and the outer layer member located in the annular groove portion.

8. A plastic bottle having an inner layer member and an outer layer member, a plug portion having a threaded portion, a cover located below the threaded portion, a support ring located below the cover, and an annular groove formed on the outer surface between the cover and the support ring; a bottle body connected to the spout portion, The threaded portion and the turntable are formed on the inner layer member, The support ring is formed on the outer layer member, The bottle body is formed from both the inner layer member and the outer layer member, A plastic bottle, wherein the boundary line between the inner layer member and the outer layer member is located in the annular groove portion.

9. A plastic bottle having an inner layer member and an outer layer member, a plug portion having an annular protrusion, a support ring positioned below the annular protrusion, and an annular groove formed on an outer surface between the annular protrusion and the support ring; a bottle body connected to the spout portion, The annular protrusion is formed on the inner layer member, The support ring is formed on the outer layer member, The bottle body is formed from both the inner layer member and the outer layer member, A plastic bottle, wherein the boundary line between the inner layer member and the outer layer member is located in the annular groove portion.

10. The method for manufacturing a preform according to any one of claims 1 to 7, a step of preparing the inner layer member and the outer layer member; and inserting the inner layer member inside the outer layer member.

11. The method for manufacturing a preform according to claim 10, wherein the temperature of the outer layer member is made higher than the temperature of the inner layer member in the step of inserting the inner layer member inside the outer layer member.

12. Providing a preform according to any one of claims 1 to 7; and a step of blow molding the preform.

Images