Multi-layer PET bottle with low light transmittance

Abstract

The multi-layer bottle includes a core layer having a first side and a second side, the core layer including an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof, an inner layer located on the first side of the core layer, the inner layer including the first polyester polymer, and an outer layer located on the second side of the core layer, the outer layer including the second polyester polymer. The multi-layer bottle has a light transmittance of less than or equal to 1% in a wavelength range of 400 to 700 nm and an ash content of less than or equal to 1% by weight.

Description

[Technical Field]

[0001] This application was filed as a PCT international application on February 7, 2024, and claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 484,220, filed February 10, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to multi-layer bottles containing at least three layers, and more particularly to such bottles having low light transmittance and being substantially free of inorganic pigments or colorants. [Background technology]

[0003] Bottles for use as containers for dairy products or beverages have specific structural light and oxygen barrier properties that ensure product quality and desirable shelf life. However, meeting these requirements can be adversely affected by ease of recyclability. It would be beneficial if bottle structures and compositions could be designed to maintain current structural light and oxygen barrier properties with improved recyclability. It is to these ends, therefore, that the present disclosure is generally directed. Summary of the Invention [Problem to be solved by the invention]

[0004] Summary of the Invention This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify essential or essential features of the claimed subject matter. This Summary is not intended to be used to limit the scope of the claimed subject matter. [Means for solving the problem]

[0005] Multilayer bottles are disclosed and described herein. An exemplary multilayer bottle can include: (a) a core layer having a first side and a second side (the core layer includes an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof); (b) an inner layer located on the first side of the core layer (the inner layer includes a first polyester polymer); and (c) an outer layer located on the second side of the core layer (the outer layer includes a second polyester polymer). The multilayer bottle can be characterized by a light transmittance of less than or equal to 1% in the wavelength range of 400-700 nm and an ash content of less than or equal to 1% by weight. These multilayer bottles can contain, or be configured to contain, dairy products or carbonated soft drinks, but are not limited thereto.

[0006] Both the above summary and the following detailed description provide examples and are illustrative only. Thus, the above summary and the following detailed description should not be considered limiting. Furthermore, features or variations in addition to those described herein may be provided. For example, particular embodiments may be directed to combinations and subcombinations of the various features described in the detailed description. [Brief explanation of the drawings]

[0007] [Figure 1] 1 shows an example of a three-layer bottle structure according to one embodiment of the present invention. [Figure 2] 1 shows an example of a four-layer bottle structure according to one embodiment of the present invention. [Figure 3] 1 shows an example of a five-layer bottle structure according to one embodiment of the present invention. [Figure 4] 1 shows an example of a seven-layer bottle structure according to one embodiment of the present invention. [Figure 5] 1 is a photograph of a multilayer bottle and a multilayer preform according to Example 1. [Figure 6] 1 is a photograph showing the location of the test panel for the multi-layer bottle of Example 1. [Figure 7]1 is a plot of light transmittance (%) versus wavelength (nm) for the bottles of Example 1 and Comparative Example 2. [Figure 8] 1 is a plot of light transmittance (%) versus wavelength (nm) for the bottles of Examples 3 to 6 and Comparative Example 7. [Figure 9] 1 is a plot of light transmittance (%) versus wavelength (nm) for the bottles of Examples 3-4 and Comparative Example 7. [Figure 10] 1 is a plot of light transmittance (%) versus wavelength (nm) for the bottles of Examples 8-9. DETAILED DESCRIPTION OF THE INVENTION

[0008] definition The following definitions are provided to more clearly define the terms used herein. Unless otherwise indicated, the following definitions are applicable to this disclosure. When a term is used in this disclosure but is not specifically defined, a definition from the IUPAC Compendium of Chemical Terminology, 2nd Ed (1997) can be applied, unless that definition conflicts with any other disclosure or definition applicable herein or would render the claim to which the definition applies unclear or unusable. To the extent that any definition or usage provided by any document incorporated by reference herein conflicts with the definition or usage provided herein, the definition or usage provided herein shall control.

[0009] The subject features are described herein such that, within particular embodiments, combinations of different features can be envisioned. For each and every embodiment and each and every feature disclosed herein, all combinations that do not adversely affect the design, composition, process, or method described herein are contemplated and can be interchanged with or without the explicit recitation of a specific combination. Thus, unless expressly recited otherwise, any embodiment or feature disclosed herein can be combined to describe an inventive design, composition, process, or method consistent with the present disclosure.

[0010] While compositions and methods are described herein in terms of "comprising" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" various components or steps, unless otherwise indicated. For example, a multi-layer bottle consistent with embodiments of the present invention may include; alternatively, may consist essentially of; or alternatively, may consist of; a core layer, an inner layer, and an outer layer.

[0011] The terms "a," "an," and "the" are intended to include plural alternatives, e.g., at least one, unless otherwise specified. For example, disclosure of a "first polyester polymer" or a "second polyester polymer" is meant to encompass mixtures or combinations of one or more than one (first polyester polymer or second polyester polymer) unless otherwise specified.

[0012] The term "contacting" is used herein to refer to materials or components that may be blended, mixed, slurried, dissolved, reacted, processed, compounded, or otherwise combined in some other manner or by any suitable method. The materials or components may be contacted together in any order, in any manner, and for any period of time, unless otherwise specified.

[0013] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, exemplary methods and materials are described herein.

[0014] All publications and patents mentioned herein may be used in connection with the present invention and are hereby incorporated by reference in their entirety for the purpose of describing and disclosing, for example, the concepts and methodologies described in the publications and patents.

[0015] Several types of ranges are disclosed in the present invention. When any series of types is disclosed or claimed, it is intended to individually disclose or claim each possible number that such range can reasonably encompass, including the endpoints of the ranges and any subranges and combinations of subranges subsumed therein. As a representative example, the relative thickness of the core layer compared to the total thickness of the multi-layer bottle may be within a particular range in various embodiments of the present invention. A disclosure that the thickness of the core layer may range from 1% to 25% of the total bottle thickness is intended to state that the thickness of the core layer may be any amount within that range, for example, 1% to 25%, for example, 3% to 20%, 5% to 15%, or 7% to 13%, or any range or combination of ranges. Similarly, all other ranges disclosed herein should be construed in a similar manner to this example.

[0016] Generally, amounts, sizes, designs, parameters, ranges, or other quantities or characteristics are "about" or "approximately," whether or not expressly stated. Whether or not modified by the term "about" or "approximately," the claims include equivalents to the quantities or characteristics.

[0017] Detailed Description of the Invention Disclosed herein are multilayer bottles that have improved recyclability and are substantially free of inorganic pigments or colorants. These multilayer bottles can have (a) a core layer having a first side and a second side (the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof), (b) an inner layer located on the first side of the core layer (the inner layer comprising a first polyester polymer), and (c) an outer layer located on the second side of the core layer (the outer layer comprising a second polyester polymer). The multilayer bottles can be characterized by a light transmittance of less than or equal to 1% in the wavelength range of 400 to 700 nm and an ash content of less than or equal to 1% by weight.

[0018] Without being bound by theory, it is believed that an opaque multi-layer bottle construction (wherein the inner and outer layers contain, for example, clear PET, and the core layer contains an opacifying additive and a suitable PET or hydrolyzable polymer (or a combination of these polymers), but lacks inorganic pigments and colorants) allows such opaque bottles to be readily recycled alongside the PET bottle stream in existing material recovery facilities (MRFs) operating on a large scale.

[0019] Multi-layer bottle Embodiments of the present invention are directed to multilayer bottles comprising (or consisting essentially of, or consisting of) (a) a core layer having a first side and a second side (the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof), (b) an inner layer located on the first side of the core layer (the inner layer comprising a first polyester polymer), and (c) an outer layer located on the second side of the core layer (the outer layer comprising a second polyester polymer). In some embodiments, the multilayer bottle can have three layers, generally described as the inner layer, the core layer, and the outer layer, while in other embodiments, the multilayer bottle can have four or more layers. Thus, the core layer is not limited to only an intermediate layer between the inner layer and the outer layer; i.e., other layers can be present. The inner layer and the outer layer are described as being located on the first and second sides, respectively, of the core layer. Additional layer(s) can be between the core layer and the inner layer, and similarly between the core layer and the outer layer.

[0020] Various combinations of layers can be present in multilayer bottles consistent with the present invention. Figures 1-4 illustrate representative 3-layer, 4-layer, 5-layer, and 7-layer multilayer bottle structures, respectively. These and other non-limiting layer arrangements are as follows, where letters are used to represent the bottle layers: I / C / O, I / M / C / O, I / C / M / O, I / M / M / C / O, I / M / C / M / O, I / M / M / C / M / O, I / M / M / C / M / O, I / M / M / M / C / O, I / M / M / C / M / M / O, I / M / M / M / C / M / O, and I / M / C / M / M / M / O. In these examples, "C" represents the core layer, "I" represents the inner layer, "O" represents the outer layer, and "M" represents the various or intermediate layers. Optionally, the inner layer, the outer layer, or both can be coated with an additional material. Layers that are adjacent to each other are described as being attached or adjacent to each other. For example, in the multilayer structure I / M / C / O, the "O" layer is attached or adjacent to the second side of the "C" layer, which is also located on the second side of the "C" layer. Similarly, the "I" layer is not adjacent or attached to the first side of the "C" layer, but is located on the first side of the "C" layer. Thus, by referring to a given layer as being located on a side of the core layer, the given layer can be adjacent to or attached to the core layer, or additional layer(s) (e.g., "M") can be between the given layer and the core layer. There is no upper limit on the total number of layers in the multilayer bottle according to the present invention, e.g., 7-layer and 9-layer structures, provided that an inner layer, a core layer, and an outer layer are present in the multilayer bottle structure. The materials that can be used in the inner layer, core layer, outer layer, and various layer(s) are described herein and can be utilized in any combination without limitation to further describe the multi-layer bottle structure.

[0021] Figure 1 illustrates a three-layer bottle having an I / C / O layer arrangement. Specifically, in this multilayer bottle, the inner layer is adjacent to a first side of the core layer, and the outer layer is adjacent to a second side of the core layer. As described above and illustrated in Figures 2-4, multilayer bottles contemplated herein can have four or more layers; for example, a multilayer bottle can have five layers or seven layers. Thus, various layers or intermediate layers (or layers) can be between the inner layer and the core layer and / or between the outer layer and the core layer.

[0022] In one embodiment, the multi-layer bottle can be a three-layer structure, where an inner layer is adjacent to a first side of the core layer and an outer layer is adjacent to a second side of the core layer. In another embodiment, the multi-layer bottle can be a five-layer structure (or a seven-layer structure or a nine-layer structure), where a first intermediate layer (or two or more first intermediate layers) is located between the inner layer and the core layer and a second intermediate layer (or two or more second intermediate layers) is located between the outer layer and the core layer.

[0023] The multilayer bottles described herein are not limited to any particular wall thickness, but multilayer bottles useful in many end uses generally have an average wall thickness in the range of 100 to 500 microns. In certain embodiments, the average wall thickness may range from 150 to 400 microns, 175 to 350 microns, 200 to 400 microns, or 200 to 300 microns, etc.

[0024] The core layer of a multi-layer bottle can, in some embodiments, comprise, on average, 1% to 25% or 3% to 20% of the total wall thickness, while in other embodiments, the core layer can, on average, comprise 5% to 15% or 7% to 13% of the total wall thickness. Similarly, the outer and inner layers of a multi-layer bottle can independently comprise, on average, 30% to 60% of the wall thickness; alternatively, 35% to 55%; alternatively, 35% to 50%; or alternatively, 40% to 50%. The sum of these layer percentages for the inner, core, and outer layers does not exceed 100%, but in cases where the total is less than 100%, the remaining thickness can come from one or more of the various layers described herein. For example, an exemplary multi-layer bottle can have 10% core layer, 45% inner layer, and 45% outer layer. As another example, an exemplary multi-layer bottle may have 15% core layers, 30% inner layers, 40% outer layers, and 15% various layers between the inner and core layers.

[0025] Advantageously, multi-layer bottles according to the present invention can have a relatively low oxygen transmission rate (for a particular set of storage conditions and shelf life) so as to reduce oxidative degradation of the contents of the bottle. For example, the bottle can have a transmission rate of 0.05 to 100 cc / m 2 The bottle may have an oxygen transmission rate (OTR) in the range of 0.1 to 50 cc / m / day. Often, the OTR of the bottle is in the range of 0.1 to 50 cc / m / day in one embodiment, 1 to 30 cc / m / day in another embodiment, 2 to 25 cc / m / day in yet another embodiment, and 0.05 to 5 cc / m / day in yet another embodiment. 2 Oxygen transmission rate (OTR) is measured at 25° C. and 50% RH with any suitable gas permeation device, for example, a Mocon OX-TRN model 2 / 61.

[0026] The multi-layer bottles described herein can have a relatively high opacity to prevent UV / light-induced degradation of the bottle contents (for a particular set of storage conditions and shelf life). In one embodiment, for example, the bottle can have a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) at wavelengths in the 400-700 nm range. In another embodiment, the bottle can have a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) at wavelengths in the 400-670 nm range. In yet another embodiment, the bottle can have a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) over any suitable range of wavelengths in the 400-700 nm range (or the 400-670 nm range) (e.g., 400-550 nm). In yet another embodiment, the bottle can have a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) over (all) wavelengths in the 400-670 nm range. The light transmittance characteristics of the multilayer bottle are determined by UV-Vis as further described herein. Light transmittance is the ratio of the light intensity of radiation leaving a substrate (e.g., the wall of a bottle) to the light intensity applied as incident light on the substrate. The measurement of these intensities is perpendicular to the direction of radiation on the substrate surface.

[0027] Advantageously, the disclosed multilayer bottle is substantially free of inorganic pigments or colorants, such as titanium dioxide (TiO). Thus, the above-described light transmittance feature can be achieved without the traditional requirement for high pigment or colorant loadings. One measure of this feature is the ash content of the multilayer bottle, which can typically be less than 1% by weight. In some embodiments, the bottle can have a lower ash content, e.g., equal to or less than 0.5% by weight, equal to or less than 0.3% by weight, or equal to or less than 0.2% by weight, while in other embodiments, the bottle can have an even lower ash content, e.g., equal to or less than 0.1% by weight, equal to or less than 0.05% by weight, or equal to or less than 0.01% by weight. Ash content is the amount of material (in weight percent) remaining in a TGA test at 800°C. A PerkinElmer Pyris1 TGA unit with an approximate sample size of 25 mg, a gas environment of air (20 mL / min), and a heating rate of 10° C. / min was used.

[0028] The multi-layer bottles described herein can be used in a variety of end uses, for example, they can contain (or be configured to contain) dairy products or carbonated soft drinks.

[0029] Any suitable method can be used to produce the multilayer bottle. The multilayer bottle can be produced using an overmolding process, or the multilayer bottle can be produced by injection molding a multilayer preform and then blow molding the multilayer preform, or the multilayer bottle can be produced by blow molding a coextruded (multilayer) polymer stream. The present invention is not limited by any particular technique or methodology used to produce the multilayer bottle.

[0030] In embodiments in which a multilayer bottle is produced by injection molding a multilayer preform and then blow molding the multilayer preform, the average wall thickness of the preform is often in the range of 2 to 5 mm and the average wall thickness of the bottle is in the range of 200 to 500 microns. A typical drawdown ratio from preform thickness to bottle thickness can be approximately 10:1, although drawdown ratios in the range of 5:1 to 20:1 are also suitable.

[0031] In particular, but not necessarily limited to, when the core layer contains a polymer other than polyester, the multilayer bottle can contain at least 97% by weight of polyester in one embodiment of the invention. In another embodiment, the multilayer bottle can contain at least 98% by weight of polyester, in yet another embodiment, the multilayer bottle can contain at least 99% by weight of polyester, and in yet another embodiment, the multilayer bottle can contain at least 99.5% by weight (or at least 99.7% by weight) of polyester. Additionally or alternatively, the multilayer bottle can often contain less than or equal to 5% by weight or less than or equal to 3% by weight of opacifying additive, which can vary considerably based on the relative thickness of the core layer. Nevertheless, in some embodiments, the multi-layer bottle can contain less than or equal to 2 wt.% opacifying additive; alternatively, less than or equal to 1.5 wt.% opacifying additive; alternatively, less than or equal to 1 wt.% opacifying additive; alternatively, less than or equal to 0.5 wt.% opacifying additive; or alternatively, less than or equal to 0.25 wt.% opacifying additive. Exemplary and non-limiting ranges for the amount of opacifying additive in the multi-layer bottle include 0.1-3 wt.%, 0.25-2 wt.%, 0.25-1.5 wt.%, 0.35-2 wt.%, 0.35-1.5 wt.%, 0.5-1.5 wt.%, or 0.5-1 wt.% opacifying additive.

[0032] Core layer The core layer of the multilayer bottle can include an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof. Thus, in one aspect, the core layer can include a core polyester polymer, while in another aspect, the core layer can include a hydrolyzable polymer, and in yet another aspect, the core layer can include a core polyester polymer and a hydrolyzable polymer in any suitable relative amounts. In certain aspects of the present invention, the core layer does not contain a pigment or colorant.

[0033] Referring first to embodiments in which the core layer comprises a hydrolyzable polymer, any suitable hydrolyzable polymer can be present in the core layer. However, the hydrolyzable polymer is generally selected so that the bottle flakes peel off and / or the core layer dissolves in stirred 1 wt. % NaOH in aqueous solution at 85° C. in less than or equal to 30 minutes, preferably less than or equal to 25 minutes, less than or equal to 20 minutes, or less than or equal to 15 minutes. The bottle flakes are generally of any suitable size, such as less than or equal to 12 mm in diameter, or less than or equal to 9.5 mm in diameter. Additionally or alternatively, the hydrolyzable polymer present in the core layer can be any polymer that causes the bottle flakes to meet the PET-P-04 test of the Association of Plastic Recyclers (2019).

[0034] The hydrolyzable polymer can include any suitable water-soluble polymer, and the polymer can be natural or synthetic, and can be a homopolymer or a copolymer. Representative and non-limiting examples of hydrolyzable polymers that can be present in the core layer of the multilayer bottle include polyvinyl alcohol (PVOH), partially hydrolyzed polyvinyl alcohol esters, partially hydrolyzed polyvinyl acetate, or polyglycolic acid (PGA). A mixture or combination of two or more hydrolyzable polymers (or a mixture of a hydrolyzable polymer and a non-hydrolyzable polymer) can be utilized in the core layer. In some embodiments, for example, the hydrolyzable polymer can include polyvinyl alcohol (PVOH), while in other embodiments, the hydrolyzable polymer can include polyglycolic acid (PGA).

[0035] Regardless of the type of hydrolyzable polymer, such polymers can be further characterized by their degree of hydrolysis. Often, the degree of hydrolysis of hydrolyzable polymers ranges from 50% to 99%, and often, the degree of hydrolysis of hydrolyzable polymers falls within the ranges of 60% to 95%, 70% to 90%, or 70% to 85%. If the degree of hydrolysis is too high, the bottle will not peel and / or the core layer will not dissolve rapidly enough in the corrosive solution during the recycling process.

[0036] Although the inner and outer layers (and other intermediate or miscellaneous layers, if present) may contribute to the opacity of the multilayer bottle, the majority of the opacity and low light transmission comes from the core layer. The opacity / light transmission can often be attributed to light scattering, or light absorption, or light reflection, or any combination thereof, in the core layer. In one aspect, the opacity of the core layer can be attributed, at least in part, to foaming the hydrolyzable polymer. Thus, in this aspect, the core layer can comprise a foamed hydrolyzable polymer.

[0037] Turning now to embodiments in which the core layer comprises a core polyester polymer, illustrative and non-limiting examples of polymers that can be utilized as the core polyester polymer include polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), polybutylene terephthalate, polylactic acid (PLA), polyhydroxyalkanoate (PHA), or combinations thereof. In one embodiment, the core polyester polymer can have a density of at least 1.05 g / cc, at least 1.1 g / cc, or at least 1.2 g / cc.

[0038] In addition to the core polyester polymer and / or hydrolyzable polymer, the core layer can contain an opacifying additive as described herein. Typically, the core layer contains at least 50%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99% by weight of the polymer component (polyester and / or hydrolyzable polymer(s)). Thus, the amount of opacifying additive (or the total of opacifying additives, if multiple types) in the core layer is often less than or equal to 50%, less than or equal to 25%, less than or equal to 15%, less than or equal to 12%, less than or equal to 10%, less than or equal to 8%, less than or equal to 5%, or less than or equal to 2% by weight. Typical ranges of the opacifying additive in the core layer can include, but are not limited to, 1-20% by weight, 2-15% by weight, 3-20% by weight, 4-15% by weight, or 5-12% by weight of the opacifying additive.

[0039] Without limitation, the opacifying additive can include any suitable organic opacifier, i.e., the opacifying additive is not a mineral or a pigment. As an example, the opacifying additive can include a polyolefin without a colorant that achieves opacity, which may or may not be miscible or compatible with the polymer(s) in the core layer. Illustrative and non-limiting examples of opacifying additives include polymethylpentene, cyclic olefin copolymers, hydrogenated styrenic polymers or copolymers, siloxanes, solid light-scattering pigments, cristobalite, and the like, as well as any mixtures or combinations thereof. Representative cyclic olefin copolymers include ethylene / norbornene copolymers, ethylene / tetracyclodecene copolymers, and the like, and combinations of two or more cyclic olefin copolymers can be utilized as opacifying additives. Representative solid light-scattering pigments include, for example, titanium dioxide, metal oxide particles, barium sulfate, zinc sulfide, and the like, as well as combinations thereof.

[0040] In one embodiment, an opacifying additive suitable for use in the core layer can have a DSC melting point in the range of 200 to 250° C., such as, for example, 210 to 250° C., 225 to 240° C., or 230 to 235° C. Additionally or alternatively, the opacifying additive can have a glass transition temperature (Tg) in the range of 115 to 145° C. in one embodiment, 120 to 140° C. in another embodiment, 120 to 135° C. in yet another embodiment, and 125 to 130° C. As disclosed herein, the opacifying additive can be a polymer that is immiscible or incompatible with the polymer used in the core layer.

[0041] inner layer and outer layer The multilayer bottles described herein can include (a) a core layer having a first side and a second side (the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof), (b) an inner layer located on the first side of the core layer (the inner layer comprising a first polyester polymer), and (c) an outer layer located on the second side of the core layer (the outer layer comprising a second polyester polymer). In some embodiments, the inner and outer layers can have the same composition (comprise the same polymer or the same blend of polymers), or alternatively, the inner and outer layers can have different compositions (comprise different polymers or different blends of polymers).

[0042] Illustrative, non-limiting examples of polymers that can be utilized as the first polyester polymer and / or the second polyester polymer include polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), polybutylene terephthalate, polylactic acid (PLA), polyhydroxyalkanoate (PHA), or combinations thereof. In one embodiment, the first polyester polymer and the second polyester polymer can comprise the same polymer, although this is not a requirement; optionally, the first polyester polymer and the second polyester polymer can independently have a density of at least 1.05 g / cc, at least 1.1 g / cc, or at least 1.2 g / cc. In addition to the first polyester polymer in the inner layer and the second polyester polymer in the outer layer, the inner and outer layers, in certain embodiments of the present invention, do not contain pigments or colorants.

[0043] As an example, a typical bottle structure may be PET / core layer / PET, with the core layer selection described above. The PET may be from any source (e.g., virgin, recycled, enhanced recycled) or any combination of sources in different relative amounts. Enhanced recycled refers to PET that has been depolymerized into its monomer(s) and then repolymerized into PET.

[0044] Generally, the inner layer contains at least 90%, at least 95%, at least 98%, or at least 99% by weight of the first polyester polymer, and the outer layer contains at least 90%, at least 95%, at least 98%, or at least 99% by weight of the second polyester polymer.

[0045] Other Layers and Additives In some embodiments of the present invention, the multilayer bottle can include various layers or intermediate layers. Any of the various layers or intermediate layer(s) that may be present in the multilayer bottle can include any of the polymers discussed above as polymer options for the core layer, inner layer, and / or outer layer. Optionally, the various layers or intermediate layers can be tie layers and / or layers that include regrind. Tie layers can be used to promote adhesion between any two layers, for example, between the core layer and the inner layer.

[0046] Additives are often used in polymer bottles and formulations to improve the processing or ease of manufacturing of the polymer and multilayer bottle. Another use of additives is to impart specific properties or characteristics to the multilayer bottle. In embodiments of the present invention, one or more additives can be used in the inner layer, and / or outer layer, and / or core layer, and / or any of the various or intermediate layers that may be present. Suitable additives that can be used in the multilayer structures or formulations disclosed herein include, but are not limited to, antioxidants, acid scavengers, anti-blocking additives, lubricants, colorants, fillers, polymer processing aids, UV inhibitors, and the like (including combinations thereof). Such materials are well known to those skilled in the art and are described, for example, in Modern Plastics Encyclopedia, Mid-November 1995 Issue, Vol. 72, No. 12; and Film Extrusion Manual - Process, Materials, Properties, TAPPI Press, 1992. [Example]

[0047] Example The present invention is further illustrated by the following examples, which are not to be construed as imposing limitations on the scope of the present invention. Various other embodiments, modifications thereof, and equivalents may occur to those skilled in the art after reading the description herein without departing from the spirit of the invention or the scope of the appended claims.

[0048] Example 1 and Comparative Example 2 Figure 5 shows photographs of the multilayer bottle and multilayer preform of Example 1, which were produced as follows. Multilayer A / B / A injection-molded preforms were first prepared using an Arburg injection molding unit with a 165-ton clamp and two-cavitation tooling mold to produce a 21.2 g preform with a 38 mm finish, 69.1 mm overall length, 3.4 mm maximum wall thickness, and 4 mm gate trace diameter. The extrusion system was configured to produce a preform with a 45 / 10 / 45 layer ratio (hence, a 10% core layer). The inner and outer ("A") layers were 100 wt% PET (DAK B90A), and the core layer was a blend of 92.5 wt% PET (DAK B90A) and 7.5 wt% opacifying additive. The amount of opacifying additive in the overall multilayer bottle structure was therefore 0.75 wt%. Prior to molding, all PET materials were dried to a level of less than 20 ppm HO. TGA testing on the opacifying additive showed insignificant amounts of ash (less than 0.5 wt%), which translates to less than 50 ppm in the overall multi-layer bottle structure. The opacifying additive had two DSC melting points at temperatures of approximately 230°C and 234°C, and a glass transition temperature (Tg) of approximately 130°C.

[0049] The extruders delivering the inner and outer layers had a 30 mm screw diameter and a 25:1 L / D ratio, while the extruder delivering the core layer had a 16 mm screw diameter and a 25:1 L / D ratio. All melt channels in the injectors and the hot runner unit (feed zone, metering zone, sprue, manifold, and nozzle temperatures) were all set at 280°C. Injector A had a 58 mm fill position and a 21.2 mm / s fill speed, and injector B had a 27 mm fill position and a 25 mm / s fill speed. Injector B filled the core layer (10 wt%) over a 55 mm length located between the finish and end cap of the preform. The hold phase process time was 8.5 seconds, the cooling phase process time was 6 seconds, and the tooling mold cooling circuit was 10°C. The total injection molding process time was 25.7 seconds.

[0050] The injection-molded preforms were blown using a Sidel blow molding unit at a preform temperature of 138°C. The blow molding process parameters included a 0.14 second pre-blow time, a 0.912 second blow time, a 1.34 second compensation time, and a 0.2 second exhaust time. The blow molding unit was equipped with a 14 mm flat stretch rod, and the cooling shield was set 2 mm away from the preform and 2 mm above the neck support ledge. The pre-blow pressure set point was 8 bar, and the flow limiter was set to 150. The pre-blow delay was 2.50 / 10. The high blow pressure used was 35 bar. The draw speed was 1.9 m / s. The mold cooling circuit was set to 12°C.

[0051] The wall thickness and light transmittance of the multi-layer bottles of Example 1 and Comparative Example 2 were tested. The multi-layer bottle of Example 1 was configured to hold approximately 11.5 fluid ounces. Comparative Example 2 was a white pigmented single-wall bottle (containing approximately 3% TiO2 by weight in the overall structure) and was configured to hold approximately 14 fluid ounces. Figure 6 is a photograph showing the location of the test panel for the multi-layer bottle of Example 1, which is the second panel from the top of the bottle. Thus, the bottle thickness and light transmittance on this section of the multi-layer bottle were tested. The average bottle thickness for both Example 1 and Comparative Example 2 was 0.30 mm (300 microns).

[0052] Light transmittance was measured using a Thermo Fisher Scientific Evolution 300 UV-Vis spectrophotometer and the following test parameters: baseline correction of 100% T baseline, % transmittance data mode, 200-800 nm wavelength band, 2 nm bandwidth, 240 nm / min scan speed, 1 nm data interval, xenon lamp change, 1 cycle, and cycle time set to automatic. The results of the light transmittance tests for the bottles of Example 1 and Comparative Example 2 are summarized in Figure 7. Note that both bottles had light transmittance values ​​well below 1% and well below 0.25% across all wavelengths within the 200-800 nm range. While the bottle of Example 1 did not achieve light transmittance values ​​as low as the bottle of Comparative Example 2, the light transmittance values ​​for the bottle of Example 1 in the 400-700 nm range were within the very low range of 0.1-0.15%. Advantageously, the bottle of Example 1 had an ash content of less than 50 ppm (e.g., from inorganic pigments or colorants).

[0053] In short, it was unexpected that only 7.5 wt. % of the opacifying additive in the core layer of the multi-layer bottle of Example 1 (and only 0.75 wt. % of the opacifying additive in the overall multi-layer bottle structure) would result in such low light transmittance values. The extremely high light protection with much lower additive loading compared to the single-layer bottle was achieved by placing only the opacifying additive in the core layer and subjecting the bottle to sufficient orientation during molding during manufacturing to dramatically increase its light blocking properties.

[0054] Examples 3 to 6 and Comparative Example 7 Examples 3-6 were produced in the same manner as Example 1, but with the following layer arrangements and compositions. Example 3 had a layer ratio of 47.5 / 5 / 47.5 (hence, a 5% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 90% by weight PET (DAK B90A) and 10% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 3 was therefore 0.5% by weight.

[0055] Example 4 had a layer ratio of 46.25 / 7.5 / 46.25 (hence, a 7.5% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 90% by weight PET (DAK B90A) and 10% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 4 was therefore 0.75% by weight.

[0056] Example 5 had a layer ratio of 47.5 / 5 / 47.5 (hence, a 5% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 95% by weight PET (DAK B90A) and 5% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 5 was therefore 0.25% by weight.

[0057] Example 6 had a layer ratio of 46.25 / 7.5 / 46.25 (hence, a 7.5% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 95% by weight PET (DAK B90A) and 5% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 6 was therefore 0.375% by weight.

[0058] The wall thickness and light transmittance of the multi-layer bottles of Examples 3-6 and Comparative Example 7 were tested. The multi-layer bottles of Examples 3-6 were configured to hold approximately 11.5 fluid ounces, while Comparative Example 7 was a white pigment single-wall bottle similar to Comparative Example 2 (containing approximately 3% TiO2 by weight in the overall structure) and configured to hold approximately 14 fluid ounces. Bottle thickness and light transmittance were tested on the same sections of the multi-layer bottle as in Examples 1 and Comparative Example 2. The average bottle thickness for the bottles of Examples 3-6 was 0.26-0.27 mm (260-270 microns), and the average bottle thickness for the bottle of Comparative Example 7 was 0.30 mm (300 microns).

[0059] The results of the light transmittance tests for the bottles of Examples 3-6 and Comparative Example 7 are summarized in Figures 8-9. While the light transmittance values ​​were less than 1% for the bottles of Examples 5-6 at lower wavelengths, the light transmittance values ​​were 1% or greater across all wavelengths within the 200-800 nm range, as shown in Figure 8. Note that Examples 5-6 have the lowest amount of opacifying additive in the overall multi-layer bottle structure, ranging from 0.25% to 0.375% by weight.

[0060] The results of the light transmittance tests for the bottles of Examples 3-4 and Comparative Example 7 are shown in Figure 9 with a maximum light transmittance (y-axis) of 1%. Advantageously, all bottles had light transmittance values ​​well below 1% across all wavelengths in the 200-800 nm range. While the bottles of Examples 3-4 did not achieve light transmittance values ​​as low as the bottle of Comparative Example 7, the light transmittance values ​​for the bottles of Examples 3 and 4 in the 400-670 nm range were in the very low range of 0.3-0.5% and 0.1-0.2%, respectively. Advantageously, the bottles of Examples 3-4 had substantially no ash (e.g., from inorganic pigments or colorants).

[0061] In short, it was unexpected that only 0.5 wt. % and 0.75 wt. % of the opacifying additive in the overall multi-layer bottle structure of Examples 3-4 would result in such low light transmittance values. The extremely high light protection with much lower additive loading compared to the single-layer bottle was achieved by placing only the opacifying additive in the core layer and subjecting the bottle to sufficient orientation during molding during manufacturing to dramatically increase its light blocking properties.

[0062] Examples 8-9 Examples 8-9 were produced in the same manner as Example 1, but with the following layer arrangement and composition. Example 8 had a layer ratio of 45 / 10 / 45 (hence, a 10% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 92.5% by weight PET (DAK B90A) and 7.5% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 8 was therefore 0.75% by weight.

[0063] Example 9 had a layer ratio of 46.5 / 7 / 46.5 (hence, 7% core layer). The inner and outer ("A") layers were 100% by weight PET (DAK B90A), and the core layer was a mixture of 85% by weight PVOH (Kuraray Mowilex M-05) and 15% by weight of the same opacifying additive as in Example 1. The amount of opacifying additive in the overall multi-layer bottle structure of Example 9 was therefore 1.05% by weight. PVOH was used instead of PET as a representative hydrolyzable polymer in the core layer.

[0064] The wall thickness, oxygen transmission rate, and light transmission rate of the multi-layer bottles of Examples 8-9 were tested. The multi-layer bottles of Examples 8-9 were configured to hold approximately 11.5 fluid ounces. Bottle thickness and light transmission rate were tested on the same sections of the multi-layer bottle as in Example 1 and Comparative Example 2. The average bottle thickness for the bottles of Examples 8-9 ranged from 0.26 to 0.31 mm (260 to 310 microns). The oxygen transmission rate for Examples 8 and 9 was 1.6 cc / m² at 25°C and 50% RH, respectively. 2 / day and 0.23cc / m 2 / day. Unexpectedly, the OTR for Example 9 was almost an order of magnitude lower than the OTR for Example 8. These permeabilities were calculated by measuring the oxygen permeability for the entire bottle and then converting it to cc / m2 based on the surface area of ​​the bottle. 2 was determined by converting it to / day.

[0065] The results of light transmittance testing (with 95% confidence limits) for the bottles of Examples 8-9 are shown in Figure 10 with a maximum light transmittance (y-axis) of 0.6%. Advantageously, both bottles had light transmittance values ​​well below 1% across all wavelengths in the 200-800 nm range. The light transmittance values ​​for the bottles of Examples 8-9 in the 400-670 nm range were in the very low range of less than 0.5%. Advantageously, the bottles of Examples 8-9 were substantially free of ash (e.g., from inorganic pigments or colorants).

[0066] With reference to Example 9, this example demonstrated that very low light transmittance combined with very low inorganic / ash content can be achieved with polymers other than PET, such as PVOH. Furthermore, although not tested, it is expected that a core layer containing a PVOH hydrolyzable polymer would cause the bottle to flake and / or dissolve in a stirred 1 wt% NaOH in aqueous solution at 85°C in less than or equal to 30 minutes, as described herein and in the PET-P-04 test of the Association of Plastic Recyclers (2019).

[0067] Aspects The present invention is described above with reference to numerous aspects and embodiments. Many variations will occur to those skilled in the art in light of the above detailed description. All such obvious variations are within the full intended scope of the appended claims. Other aspects of the present invention include, but are not limited to, the following (although aspects are described as "comprising", they can instead be "consisting essentially of" or "consisting of"):

[0068] Aspect 1. A multi-layer bottle including: (a) a core layer having a first side and a second side, the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof; (b) an inner layer located on the first side of the core layer, the inner layer comprising a first polyester polymer; and (c) an outer layer located on the second side of the core layer, the outer layer comprising a second polyester polymer; the bottle characterized by a light transmittance of less than or equal to 1% in a wavelength range of 400-700 nm; and an ash content of less than or equal to 1% by weight. Embodiment 2. The bottle of embodiment 1, wherein the inner layer is adjacent to the first side of the core layer. Embodiment 3. The bottle of embodiment 1, wherein the first intermediate layer (or two or more first intermediate layers) is located between the inner layer and the core layer. Embodiment 4. The bottle of any one of embodiments 1-3, wherein the outer layer is adjacent to the second side of the core layer. Embodiment 5. The bottle of any one of embodiments 1-3, wherein the second intermediate layer (or two or more second intermediate layers) is located between the outer layer and the core layer. Embodiment 6. The bottle of any one of embodiments 1-5, wherein the inner and outer layers have the same composition (e.g., the same polymer or the same blend of polymers). Embodiment 7. The bottle of any one of embodiments 1-5, wherein the inner and outer layers have different compositions (e.g., different polymers or different blends of polymers). Aspect 8. The bottle of any one of Aspects 1-7, having a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) at a wavelength in the range of 400 to 670 nm. Aspect 9. The bottle of any one of Aspects 1-7, having a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) over a range of wavelengths in the 400-700 nm range (or in the 400-670 nm range) (e.g., 400-550 nm). Aspect 10. The bottle of any one of Aspects 1-7, having a light transmittance of less than or equal to 1% (or less than or equal to 0.8%, or less than or equal to 0.6%, or less than or equal to 0.4%, or less than or equal to 0.2%) over (all) wavelengths within the 400-670 nm range. Aspect 11. The bottle of any one of Aspects 1-10, wherein the ash content is less than or equal to 0.5 wt.%, less than or equal to 0.3 wt.%, less than or equal to 0.2 wt.%, less than or equal to 0.1 wt.%, less than or equal to 0.05 wt.%, or less than or equal to 0.01 wt.%. Embodiment 12. The bottle of any one of embodiments 1-11, having a wall thickness (average) in any range disclosed herein, e.g., 100-500 microns, 150-400 microns, 175-350 microns, 200-400 microns, or 200-300 microns. Embodiment 13. The bottle of any one of embodiments 1-12, wherein the core layer is any (average) percentage of the wall thickness of a bottle disclosed herein, for example, between 1% and 25%, between 3% and 20%, between 5% and 15%, or between 7% and 13%. Embodiment 14. The bottle of any one of embodiments 1-13, wherein the outer layer is any (average) percentage of the wall thickness of a bottle disclosed herein, e.g., 30% to 60%, 35% to 55%, 35% to 50%, or 40% to 50%. Embodiment 15. The bottle of any one of embodiments 1-14, wherein the inner layer is any (average) percentage of the wall thickness of the bottle disclosed herein, e.g., 30% to 60%, 35% to 55%, 35% to 50%, or 40% to 50%. Embodiment 16. The bottle of any one of embodiments 1-15, wherein the core layer comprises a hydrolyzable polymer, wherein the hydrolyzable polymer comprises any polymer that causes flakes (diameters less than or equal to 12 mm or 9.5 mm) to peel off from the bottle and / or that dissolves in a stirred 1 wt % NaOH in aqueous solution at 85° C. in less than or equal to 30 minutes, in less than or equal to 25 minutes, in less than or equal to 20 minutes, or in less than or equal to 15 minutes.

[0023] Embodiment 17. The bottle of any one of embodiments 1-16, wherein the core layer comprises a hydrolyzable polymer, and the hydrolyzable polymer comprises any polymer such that flakes from the bottle meet the PET-P-04 test of the Association of Plastic Recyclers (2019).

[0030] Embodiment 18. The bottle of any one of embodiments 1-17, wherein the core layer comprises a hydrolyzable polymer, wherein the hydrolyzable polymer comprises any suitable water-soluble polymer, which may be natural or synthetic, and may be a homopolymer or a copolymer.

[0023] Embodiment 19. The bottle of any one of embodiments 1-18, wherein the core layer comprises a hydrolyzable polymer, the hydrolyzable polymer comprising polyvinyl alcohol (PVOH), a partially hydrolyzed polyvinyl alcohol ester, a partially hydrolyzed polyvinyl acetate, polyglycolic acid (PGA), or any combination thereof. Embodiment 20. The bottle of any one of embodiments 1-19, wherein the core layer comprises a hydrolyzable polymer, and the hydrolyzable polymer comprises polyvinyl alcohol (PVOH). Embodiment 21. The bottle of any one of embodiments 1-19, wherein the core layer comprises a hydrolyzable polymer, and the hydrolyzable polymer comprises polyglycolic acid (PGA). Embodiment 22. The bottle of any one of embodiments 1-21, wherein the core layer comprises a hydrolyzable polymer, the hydrolyzable polymer having any suitable degree of hydrolysis, e.g., between 50% and 99%, between 60% and 95%, between 70% and 90%, or between 70% and 85%.

[0033] Embodiment 23. The bottle of any one of embodiments 1-22, wherein the core layer comprises a hydrolyzable polymer, and the hydrolyzable polymer comprises an expanded hydrolyzable polymer.

[0033] Embodiment 24. The bottle of any one of embodiments 1-23, wherein the core layer comprises a core polyester polymer.

[0037] Embodiment 25. The bottle of any one of embodiments 1-24, comprising at least 97% by weight polyester, at least 98% by weight polyester, at least 99% by weight polyester, at least 99.5% by weight, or at least 99.7% by weight polyester.

[0033] Embodiment 26. The bottle of any one of embodiments 1-25, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently comprise polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), polybutylene terephthalate, polylactic acid (PLA), polyhydroxyalkanoate (PHA), or a combination thereof.

[0033] Embodiment 27. The bottle of any one of embodiments 1-26, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently comprise polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), or a combination thereof.

[0030] Embodiment 28. The bottle of any one of embodiments 1-27, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently have a density of at least 1.05 g / cc, at least 1.1 g / cc, or at least 1.2 g / cc.

[0033] Aspect 29. The bottle of any one of aspects 1-28, wherein the light transmittance of the bottle is due to light scattering, light absorption, light reflection, or any combination thereof, in the core layer. Embodiment 30. The bottle of any one of embodiments 1-29, wherein the core layer comprises less than or equal to 50%, 25%, 15%, 12%, 10%, 8%, 5%, 2%, 1-20%, 2-15%, 3-20%, 4-15%, or 5-12% by weight of the opacifying additive. Aspect 31. The bottle of any one of aspects 1-30, comprising less than or equal to 5 wt.%, 3 wt.%, 2 wt.%, 1.5 wt.%, 1 wt.%, 0.5 wt.%, 0.25 wt.%, 0.1-3 wt.%, 0.25-2 wt.%, 0.25-1.5 wt.%, 0.35-2 wt.%, 0.35-1.5 wt.%, 0.5-1.5 wt.%, or 0.5-1 wt.% of the opacifying additive.

[0033] Embodiment 32. The bottle of any one of embodiments 1-31, wherein the opacifying additive comprises any suitable opacifying additive or any opacifying additive disclosed herein.

[0023] Aspect 33. The bottle of any one of aspects 1-32, wherein the opacifying additive comprises polymethylpentene, a cyclic olefin copolymer, a hydrogenated styrenic polymer or copolymer, a siloxane, a solid light-scattering pigment, cristobalite, or any combination thereof. Aspect 34. The bottle of any one of aspects 1 to 33, wherein the opacifying additive has a DSC melting point in the range of 200 to 250°C, 210 to 250°C, 225 to 240°C, or 230 to 235°C. Aspect 35. The bottle of any one of aspects 1 to 34, wherein the opacifying additive has a glass transition temperature (Tg) in the range of 115 to 145°C, 120 to 140°C, 120 to 135°C, or 125 to 130°C.

[0036] Embodiment 36. The bottle of any one of embodiments 33-35, wherein the solid light-scattering pigment comprises titanium dioxide, metal oxide particles, barium sulfate, zinc sulfide, or any combination thereof.

[0037] Embodiment 37. The bottle of any one of embodiments 33-36, wherein the cyclic olefin copolymer comprises an ethylene / norbornene copolymer, an ethylene / tetracyclodecene copolymer, or a combination thereof. Aspect 38. 0.05 to 100, 0.1 to 50, 1 to 30, 2 to 25, or 0.05 to 5 cc / m 2 38. The bottle of any one of aspects 1-37, characterized by an oxygen transmission rate in the range of 1 / day.

[0039] Embodiment 39. The bottle of any one of embodiments 1-38, wherein the first polyester polymer and the second polyester polymer comprise the same polymer.

[0033] Aspect 40. The bottle of any one of aspects 1-39, wherein the inner and outer layers do not contain pigments or colorants.

[0033] Embodiment 41. The bottle of any one of embodiments 1 to 40, wherein the core layer does not contain a pigment or colorant. Embodiment 42. The bottle of any one of embodiments 1-41, containing (or adapted to contain) a dairy product or a carbonated soft drink. Embodiment 43. The bottle of any one of embodiments 1-42, wherein the bottle is produced using an overmolding process. Embodiment 44. The bottle of any one of embodiments 1-42, wherein the bottle is produced by injection molding a multi-layer preform and then blow molding the multi-layer preform. Embodiment 45. The bottle of any one of embodiments 1-42, wherein the bottle is produced by blow molding a coextruded (multilayer) polymer stream. Aspect 46. A multilayer bottle comprising: (a) a core layer having a first side and a second side, the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof; (b) an inner layer positioned on the first side of the core layer, the inner layer comprising a first polyester polymer; and (c) an outer layer positioned on the second side of the core layer, the outer layer comprising a second polyester polymer; wherein the bottle has an optical transmittance of less than or equal to 1% (or less than or equal to 0.8%) at a wavelength in the range of 400 to 700 nm. or equal to or less than 0.6%, or equal to or less than 0.4%, or equal to or less than 0.2%; and an ash content of equal to or less than 1% by weight (or equal to or less than 0.5% by weight, or equal to or less than 0.3% by weight, or equal to or less than 0.2% by weight, or equal to or less than 0.1% by weight, or equal to or less than 0.05% by weight, or equal to or less than 0.01% by weight). Aspect 47. A bottle having a light transmittance of 1% or less (or 0.8%, or 0.6%, or 0.4%, or 0.2%) over (all) wavelengths in the 400 to 670 nm range; 47. The bottle of embodiment 46, wherein the average percentage of the wall thickness is 1 to 20%, 2 to 15%, 3 to 20%, 4 to 15%, or 5 to 12% by weight of the opacifying additive; and / or the bottle comprises 0.1 to 3%, 0.25 to 2%, 0.25 to 1.5%, 0.35 to 2%, 0.35 to 1.5%, 0.5 to 1.5%, or 0.5 to 1% by weight of the opacifying additive.

[0047] Embodiment 48. The bottle of embodiment 46 or 47, wherein the core layer comprises a hydrolyzable polymer, and the hydrolyzable polymer comprises polyvinyl alcohol (PVOH); or wherein the core layer comprises a core polyester polymer, and the bottle comprises at least 97% by weight polyester, at least 98% by weight polyester, at least 99% by weight polyester, at least 99.5% by weight, or at least 99.7% by weight polyester.

Claims

1. (a) a core layer having a first side and a second side, the core layer comprising an opacifying additive and a core polyester polymer, a hydrolyzable polymer, or a combination thereof; (b) an inner layer located on the first side of the core layer, the inner layer comprising a first polyester polymer; and (c) an outer layer on the second side of the core layer, the outer layer comprising a second polyester polymer; A multi-layer bottle comprising: The bottle is A light transmittance of less than or equal to 1% in the wavelength range of 400 to 700 nm; and Ash content less than or equal to 1% by weight Characterized by a bottle.

2. 10. The bottle of claim 1, wherein the inner layer is adjacent to the first side of the core layer.

3. 10. The bottle of claim 1, wherein a first intermediate layer, or two or more first intermediate layers, are located between the inner layer and the core layer.

4. The bottle of any one of claims 1 to 3, wherein the outer layer is adjacent to the second side of the core layer.

5. The bottle of any one of claims 1 to 3, wherein a second intermediate layer, or two or more second intermediate layers, are located between the outer layer and the core layer.

6. The bottle according to any one of claims 1 to 5, wherein the inner layer and the outer layer have the same composition.

7. The bottle according to any one of claims 1 to 5, wherein the inner layer and the outer layer have different compositions.

8. 8. The bottle of claim 1, wherein the light transmittance is less than or equal to 1%, less than or equal to 0.8%, less than or equal to 0.6%, less than or equal to 0.4%, or less than or equal to 0.2% at a wavelength in the range of 400 to 670 nm.

9. 8. The bottle according to claim 1, wherein the light transmittance is equal to or less than 1%, equal to or less than 0.8%, equal to or less than 0.6%, equal to or less than 0.4%, or equal to or less than 0.2% in a wavelength range of 400 to 700 nm or 400 to 670 nm.

10. 8. The bottle of claim 1, wherein the light transmittance is equal to or less than 1%, equal to or less than 0.8%, equal to or less than 0.6%, equal to or less than 0.4%, or equal to or less than 0.2% over the entire wavelength range in the 400 to 670 nm range.

11. 11. The bottle of any one of claims 1 to 10, wherein the ash content is less than or equal to 0.5% by weight, less than or equal to 0.3% by weight, less than or equal to 0.2% by weight, less than or equal to 0.1% by weight, less than or equal to 0.05% by weight, or less than or equal to 0.01% by weight.

12. 12. The bottle of any one of claims 1 to 11, having an average wall thickness in the range of 100 to 500 microns, 150 to 400 microns, 175 to 350 microns, 200 to 400 microns, or 200 to 300 microns.

13. 13. The bottle of any one of claims 1 to 12, wherein the core layer is between 1% and 25%, between 3% and 20%, between 5% and 15%, or between 7% and 13% of the average wall thickness of the bottle.

14. 14. The bottle of any one of claims 1 to 13, wherein the outer layer is 30% to 60%, 35% to 55%, 35% to 50%, or 40% to 50% of the average wall thickness of the bottle.

15. 15. The bottle of any one of claims 1 to 14, wherein the inner layer is 30% to 60%, 35% to 55%, 35% to 50%, or 40% to 50% of the average wall thickness of the bottle.

16. 16. The bottle of any one of claims 1 to 15, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises any polymer that flakes off when the diameter of the bottle is less than or equal to 12 mm or less than or equal to 9.5 mm, and / or the core layer dissolves in a stirred 1 wt % NaOH in aqueous solution at 85°C in less than or equal to 30 minutes, less than or equal to 25 minutes, less than or equal to 20 minutes, or less than or equal to 15 minutes.

17. 17. The bottle of any one of claims 1 to 16, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises any polymer such that flakes from the bottle meet the PET-P-04 test of the Association of Plastic Recyclers (2019).

18. The bottle according to any one of claims 1 to 17, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises a water-soluble polymer.

19. 19. The bottle of any one of claims 1 to 18, wherein the core layer comprises the hydrolyzable polymer, the hydrolyzable polymer comprising polyvinyl alcohol (PVOH), partially hydrolyzed polyvinyl alcohol ester, partially hydrolyzed polyvinyl acetate, polyglycolic acid (PGA), or any combination thereof.

20. The bottle of any one of claims 1 to 19, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises polyvinyl alcohol (PVOH).

21. The bottle of any one of claims 1 to 19, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises polyglycolic acid (PGA).

22. 22. The bottle of any one of claims 1 to 21, wherein the core layer comprises the hydrolyzable polymer, the hydrolyzable polymer having a degree of hydrolysis in the range of 50% to 99%, 60% to 95%, 70% to 90%, or 70% to 85%.

23. The bottle of any one of claims 1 to 22, wherein the core layer comprises the hydrolyzable polymer, and the hydrolyzable polymer comprises a foamed hydrolyzable polymer.

24. The bottle of any one of claims 1 to 23, wherein the core layer comprises the core polyester polymer.

25. 25. The bottle of any one of claims 1 to 24, comprising at least 97% by weight polyester, at least 98% by weight polyester, at least 99% by weight polyester, at least 99.5% by weight, or at least 99.7% by weight polyester.

26. 26. The bottle of any one of claims 1 to 25, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently comprise polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), polybutylene terephthalate, polylactic acid (PLA), polyhydroxyalkanoate (PHA), or a combination thereof.

27. 27. The bottle of any one of claims 1 to 26, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently comprise polyethylene terephthalate (PET), glycol-modified PET (PET-G), recycled PET (R-PET), or a combination thereof.

28. 28. The bottle of any one of claims 1 to 27, wherein the core polyester polymer, the first polyester polymer, and the second polyester polymer independently have a density of at least 1.05 g / cc, at least 1.1 g / cc, or at least 1.2 g / cc.

29. The bottle according to any one of claims 1 to 28, wherein the light transmittance of the bottle is due to light scattering, light absorption, light reflection, or any combination thereof in the core layer.

30. 30. The bottle of any one of claims 1 to 29, wherein the core layer comprises less than or equal to 50%, less than or equal to 25%, less than or equal to 15%, less than or equal to 12%, less than or equal to 10%, less than or equal to 8%, less than or equal to 5%, less than or equal to 2%, 1 to 20%, 2 to 15%, 3 to 20%, 4 to 15%, or 5 to 12% by weight of the opacifying additive.

31. 31. The bottle of any one of claims 1 to 30, comprising less than or equal to 5 wt%, less than or equal to 3 wt%, less than or equal to 2 wt%, less than or equal to 1.5 wt%, less than or equal to 1 wt%, less than or equal to 0.5 wt%, less than or equal to 0.25 wt%, 0.1 to 3 wt%, 0.25 to 2 wt%, 0.25 to 1.5 wt%, 0.35 to 2 wt%, 0.35 to 1.5 wt%, 0.5 to 1.5 wt%, or 0.5 to 1 wt% of the opacifying additive.

32. 32. The bottle of any one of claims 1 to 31, wherein the opacifying additive comprises any suitable opacifying additive or any opacifying additive disclosed herein.

33. 33. The bottle of any one of claims 1 to 32, wherein the opacifying additive comprises polymethylpentene, a cyclic olefin copolymer, a hydrogenated styrenic polymer or copolymer, a siloxane, a solid light-scattering pigment, cristobalite, or any combination thereof.

34. 34. The bottle of any one of claims 1 to 33, wherein the opacifying additive has a DSC melting point in the range of 200 to 250°C, 210 to 250°C, 225 to 240°C, or 230 to 235°C.

35. 35. The bottle of any one of claims 1 to 34, wherein the opacifying additive has a glass transition temperature (Tg) in the range of 115 to 145°C, 120 to 140°C, 120 to 135°C, or 125 to 130°C.

36. 36. The bottle of any one of claims 33 to 35, wherein the solid light-scattering pigment comprises titanium dioxide, metal oxide particles, barium sulfate, zinc sulfide, or any combination thereof.

37. 37. The bottle of any one of claims 33 to 36, wherein the cyclic olefin copolymer comprises an ethylene / norbornene copolymer, an ethylene / tetracyclodecene copolymer, or a combination thereof.

38. 0.05 to 100, 0.1 to 50, 1 to 30, 2 to 25, or 0.05 to 5 cc / m ２ 38. The bottle of claim 1, characterized by an oxygen transmission rate in the range of 1 / day.

39. 39. The bottle of any one of claims 1 to 38, wherein the first polyester polymer and the second polyester polymer comprise the same polymer.

40. 40. The bottle of any one of claims 1 to 39, wherein the inner and outer layers do not contain pigments or colorants.

41. The bottle according to any one of claims 1 to 40, wherein the core layer does not contain any pigments or colorants.

42. 42. A bottle according to any preceding claim containing or adapted to contain a dairy product or a carbonated soft drink.

43. 43. The bottle of any one of claims 1 to 42, produced using an overmolding process.

44. 43. The bottle of any one of claims 1 to 42 produced by injection molding a multi-layer preform and then blow molding the multi-layer preform.

45. 43. The bottle of any one of claims 1 to 42 produced by co-extrusion or blow molding of multi-layer polymer streams.

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