EP4633943A1

EP4633943A1 - Bottle and container

Info

Publication number: EP4633943A1
Application number: EP23821254.2A
Authority: EP
Inventors: Joachim Klimeck; Florian Löchel; Christian Hofmann
Original assignee: Wella Germany GmbH
Current assignee: Wella Germany GmbH
Priority date: 2022-12-16
Filing date: 2023-12-07
Publication date: 2025-10-22
Also published as: JP2025539543A; WO2024126261A1

Abstract

The presently claimed invention is directed to a bottle comprising a body and a neck surmounting the body and defining an opening of the bottle, the body and the neck being formed by a multilayer wall of the bottle, the multilayer wall of the bottle comprising at least three superimposed layers comprising at least one intermediate layer interposed between an outer layer and an inner layer, wherein the intermediate layer comprises recycled polyethylene, the outer layer comprises recycled polyethylene or virgin polyethylene, and the inner layer comprises virgin polyethylene.

Description

BOTTLE AND CONTAINER

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

Plastic is one of the world’s most-used materials. The problem with plastic lies not in how it is used but in end-of-life management of products made from it. Currently, only a small percentage of the plastic is recycled or reused, while most of the plastic ends up as waste in landfills or worse dumped in the wild and/or finds its way to the oceans. Due to this growing problem, there is an urgent need for recycling and reuse of plastic products.

A major problem in recycling plastic products is the degradation of polymeric materials such as polyethylene during their use and furthermore during the recycling process affecting their properties (e.g., strength, elasticity, optical and thermal properties, and UV resistivity). Recycled polyethylene (and products made from the recycled materials) may therefore be of lower quality than non-recycled polyethylene. Moreover, the quality of polyethylene usually decreases with every recycling process the polyethylene undergoes.

Therefore, it is difficult to obtain identical mechanical, sealing and/or aesthetic properties by using a recycled polyethylene in comparison to a virgin polyethylene. This applies in particular to multilayer wall bottles that are produced by extrusion blow molding, i.e., by co-extrusion and then blow molding, which are intended to contain products such as hair care compositions.

In order to overcome this problem, it is suggested that multilayer wall bottles contain layers which are made of individual layers which are made of differently composed materials, i.e., layers which either contain recycled polyethylene or virgin polyethylene or a mixture of both recycled and virgin polyethylene.

FR 3 121 625 describes a multilayer wall bottle that comprises an inner layer which is made of recycled polyethylene. In addition, the bottle contains additional barrier layers and adhesive layers which are made of materials that are different from polyethylene. The presence of different materials provides an impediment to the recycling of these bottles so that the bottles are not easily recyclable.

There is a need to provide a bottle comprising recycled polyethylene that has satisfactory mechanical properties, e.g., as evidenced by stress crack resistance, compared to a similar bottle that comprises virgin polyethylene exclusively and is easily recyclable. There is also the need for providing a bottle comprising recycled polyethylene that is suitable for housing a hair care composition (product) in a safely and durable manner, while being easily recyclable. There is also the need for providing a bottle comprising recycled polyethylene that may be tailored depending on its uses, while being easily recyclable. Overall, there is a need for providing a bottle comprising recycled polyethylene that exhibits a satisfactory compromise between performance (mechanical and chemical resistance, bottle design versatility, product storage stability, and product shelf-life) and recyclability.

Hence, it is an object of the presently claimed invention to provide a bottle comprising recycled polyethylene that has satisfactory mechanical properties, e.g., as evidenced by stress crack resistance, compared to a similar bottle that comprises virgin polyethylene exclusively and is easily recyclable. It is also an object to provide a bottle comprising recycled polyethylene that is suitable for housing a hair care composition in a safely and durable manner, while being easily recyclable. It is also an object to provide a bottle comprising recycled polyethylene that may be tailored depending on its used, while being easily recyclable. It is also an object to provide a cosmetic/food-grade bottle comprising recycled polyethylene that exhibits a satisfactory compromise between performance (the mechanical and chemical resistance, the bottle design versatility, product storage stability, and product shelf-life) and recyclability.

SUMMARY OF THE INVENTION

The object has been solved by manufacturing a bottle comprising an intermediate layer and optionally an outer layer made from recycled polyethylene with a specific melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) in combination with an inner layer made from virgin polyethylene. The inventors have found that a cosmetic/food-grade bottle comprising recycled polyethylene that exhibits a satisfactory compromise between the performance (mechanical and chemical resistance, bottle design versatility, product storage stability, and product shelf-life) and the recyclability is obtained, when carefully designing it in terms of the number of layers, their order, their composition and origins, and/or the choice of the parameters such as the relative proportion of the thickness of each layer to the total thickness of the multilayer wall.

Accordingly, in one aspect, the presently claimed invention is directed to a bottle comprising a body and a neck surmounting the body and defining an opening of the bottle, the body and the neck being formed by a multilayer wall of the bottle, the multilayer wall of the bottle comprising at least three superimposed layers comprising at least one intermediate layer interposed between an outer layer and an inner layer, wherein the intermediate layer comprises high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), the outer layer comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), and the inner layer comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

In another aspect, the presently claimed invention is directed to a container comprising a bottle as described herein and a cap which is rotatably mounted onto the bottle

In yet another aspect, the presently claimed invention is directed to a process for manufacturing a bottle as described herein comprising at least the step of (A) coextruding and blowing the inner layer, the intermediate layer and the outer layer each as described herein into a mold to obtain the bottle as described herein.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely exemplary in nature and is not intended to limit the presently claimed invention or the application and uses of the presently claimed invention. Furthermore, there is no intention to be bound by any theory presented in the preceding technical field, background, summary or the following detailed description.

The terms "comprising", "comprises" and "comprised of as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of as used herein comprise the terms "consisting of, "consists" and "consists of.

Furthermore, the terms "(a)", "(b)", "(c)", "(d)" etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the subject matter described herein are capable of operation in other sequences than described or illustrated herein. In case the terms “(A)”, “(B)” and “(C)” or "(a)", "(b)", "(c)", "(d)", "(i)", "(ii)" etc. relate to steps of a method or use or assay there is no time or time interval coherence between the steps, that is, the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps, unless otherwise indicated in the application as set forth herein above or below.

The term “about”, when used in relation to a weight ratio or a weight percentage, means that a specific value should be understood as meaning a range of ± 10 %. For example, the weight proportion of a compound of about 1 %, means a weight proportion ranging from 0.9 to 1 .1 %. For example, the weight proportion of a compound of about 2.5 %, means a weight proportion ranging from 2.25 to 2.75 %.

In the following passages, different aspects of the subject matter are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

Reference throughout this specification to "one embodiment" or “preferred embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the presently claimed invention. Thus, appearances of the phrases "in one embodiment" or “in a preferred embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment but may refer to different embodiments of the presently claimed invention. Furthermore, the features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some, but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the subject matter, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

Furthermore, the ranges defined throughout the specification include the end values as well, i.e. , a range of 1 to 10 implies that both 1 and 10 are included in the range. For the avoidance of doubt, the applicant shall be entitled to any equivalents according to applicable law.

For the purposes of the presently claimed invention, ‘% by weight’ or ‘wt.% ‘as used in the presently claimed invention is with respect to the total weight of the oxidative hair treatment composition. Further, the sum of wt.% of all the compounds, as described herein, in the respective components adds up to 100 wt.%.

Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests, or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

The measurement techniques described hereinabove and herein are well known to a person skilled in the art and therefore do not limit the presently claimed invention.

In one aspect, the presently claimed invention is directed to a bottle comprising a body and a neck surmounting the body and defining an opening of the bottle, the body and the neck being formed by a multilayer wall of the bottle, the multilayer wall of the bottle comprising at least three superimposed layers comprising at least one intermediate layer interposed between an outer layer and an inner layer, wherein the intermediate layer comprises high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), the outer layer comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), and the inner layer comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

The term “inner layer” refers to the layer which is in contact with the product that is housed in the bottle. The term “outer layer” refers to the layer that is furthest away from the product. The term “intermediate layer” refers to the layer that is arranged in between the inner layer and the outer layer.

Degradation during the recycling of polyethylene is responsible for the reduction of its molecular weight. Hence, recycled polyethylene comprises polyethylene that has a lower molecular weight compared with virgin polyethylene. The lower molecular weight of recycled polyethylene is reflected by a melt flow index which is higher than the melt flow index of virgin polyethylene. As the intermediate layer and optionally the outer layer comprises recycled polyethylene, these layers comprise polyethylene that has a comparatively high melt flow index.

The recycled polyethylene includes polyethylene which is the result of recycling, in particular mechanical, chemical, thermal or enzymatic recycling, which is carried out on a product that is made of polyethylene. Besides the variation of the melt flow index, a recycled polyethylene is preferably characterized by the presence of incrustations and/or specific markers. The markers may emit an electromagnetic signal that may be detected by a suitable spectrometer (reader). In an example, the markers emit a signal in response to incoming electromagnetic radiation, for example, UV, XRD, or XRF. XRF markers may be detected and measured by X-Ray Fluorescence (XRF) analysis by XRF spectrometers (readers) which may detect and identify their response (signature) signals.

The recycled polyethylene may also include additional compounds, including additives, byproducts, impurities, degradation products. The presence (and the proportions) of these additional compounds depends on the source of the used polyethylene (provider, recycling process, grade, batch, etc.). The presence or the proportions of these compounds may not necessarily be assessed, for example when they are present at a very low quantity (e.g., at a ppm level). However, these additional compounds may have a detrimental effect on the housed hair care composition, when they come into contact with it. These additional compounds may thus negatively affect the product storage stability, its shelf-life, and more generally the qualification of the bottle as a cosmetic/food-grade bottle.

In one embodiment, the intermediate layer preferably comprises recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg). In another embodiment, the outer layer preferably comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg). In one embodiment, the inner layer preferably comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

In one embodiment, the recycled high density polyethylene preferably has a density in the range from > 0.94 to < 0.96 g/cm³, more preferably in the range from > 0.945 to < 0.955 g/cm³. In one embodiment, the high density polyethylene has a density in the range from > 0.94 to < 0.96 g/cm³, more preferably in the range from > 0.950 to < 0.960 g/cm³. In one embodiment, the high density polyethylene comprised by the inner layer (8) is identical to the high density polyethylene comprised by the outer layer (7).

The bottle is distinct from a tube. In particular, the bottle has a stiffness that is greater than the stiffness of a tube. The stiffness is achieved by the choice of polyethylene, in particular the density of the polyethylene, and the choice of the wall thickness. A tube is flexible by nature because it is designed to be squeezed by a consumer to force the product out of the tube through the intended opening defined by the neck of the tube. In contrast, a bottle is designed to pour the product through the opening defined by the neck of the bottle without severely pressing the body of the bottle. In addition, during the manufacture of a tube, the neck of the tube is attached or over injected onto the extruded part of the tube. In one embodiment, the multilayer wall preferably has a thickness in the range from > 0.6 to < 1 .4 mm, more preferably in the range from > 0.8 to < 1 .2 mm. Preferably, the thickness of the intermediate layer (6) is in the range from > 30 % to < 60 % of the total thickness of the multilayer wall (5). Preferably, the thickness of the outer layer (7) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall (5). Preferably the thickness of the inner layer (8) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall. The wall thickness is being measured on a central part of the bottle which extends between the shoulder of the bottle and the bottom of the bottle, whereby both the shoulder and the bottom are not taken into account for the purpose of measuring the wall thickness. The wall thickness of the bottle can be adjusted to achieve good results in compatibility and leakage tests depending on the chemical nature of the products to be housed.

The inventors have found that there is the need for providing a bottle manufactured from a multilayer wall comprising an inner layer having a satisfactory relative thickness. Below a certain threshold, the inner layer may not achieve anymore its protective function of the hair care composition, while this is its primary goal. The product stability and shelf-life may therefore be negatively impacted, and the cosmetic/food-grade qualification of the bottle may be compromised. In contrast, above a certain threshold, the quantity (proportion) of virgin polyethylene used exceeds what is needed for obtaining a cosmetic/food-grade bottle being easily recyclable.

The inventors have found that a satisfactory compromise is reached, when the thickness of the inner layer is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall. When the bottle has a thickness of less than 20%, for example about 10 %, the bottle may not have a satisfactory resistance to stress cracking. There is also a non-neglectable risk that the hair care composition may come into contact with the middle layer of the bottle. This contact may lead to the migration of the hair care composition into the middle layers, its leakage and/or the contamination of the hair care composition with some of additional compounds present in the middle layer. Without wishing to be bound by any theory, this may be due to the challenges associated with the manufacturing of such thin layers and/or the relative thickness manufacturing tolerances, which may lead to zones being covered by an inner layer having an insufficient thickness or even being free of an inner layer. An increased relative thickness of the inner layer increases the bottle-product compatibility, without significantly impairing its recyclability profile.

In one embodiment, the bottle of the presently claimed invention does not comprise an adhesive layer. Adhesives are preferably selected from the group consisting of ethylene vinyl acetate copolymer and modified polyolefins such as modified polyolefins with the tradenames ADMER, commercially available from Mitsui Chemicals. In one embodiment, the bottle of the presently claimed invention does not comprise a barrier layer which comprises at least one polymer selected from the group consisting of ethylene vinyl alcohol, polyvinylidene chloride, acrylic acid, acrylic acid copolymers and ethylene copolymers.

In one embodiment, the bottle (1) comprises three superimposed layers.

In one embodiment, the bottle comprises a body and a neck surmounting the body and defining an opening of the bottle, the body and the neck being formed by a multilayer wall of the bottle having a thickness in the range from > 0.6 to < 1.4 mm, the multilayer wall of the bottle comprising three superimposed layers comprising at least one intermediate layer interposed between an outer layer and an inner layer, wherein the intermediate layer comprises recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), the outer layer comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), and the inner layer comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

In one embodiment, at least one of the inner layer (8), the intermediate layer (6) and the outer layer (7) preferably comprises at least one colourant. In another embodiment, each of the inner layer (8), the intermediate layer (6) and the outer layer (7) preferably comprises at least one colourant. The colourants are selected from the group consisting of dyes and pigments.

In one embodiment, the bottle has a volume in the range from > 50 mL to < 2000 mL, more preferably in the range from > 50 mL to < 1000 mL.

In another aspect, the presently claimed invention is directed to a container comprising a bottle as described herein and a cap which is rotatably mounted onto the bottle. In a preferred embodiment, the cap is configured to cooperate with the neck of the bottle, in particular by screwing, in order to seal the bottle. The cap comprises a sealing skirt which is in contact with the inside of the multilayer wall of the bottle at the level of the neck.

In another embodiment, the cap preferably comprises polypropylene. The polypropylene is preferably recycled polypropylene.

In another embodiment, the cap is preferably obtained by injection molding. In another embodiment, the bottle is preferably obtained by a coextrusion-blow-molding process.

In one embodiment, the container preferably houses a hair care composition. The hair care composition is preferably selected from the group consisting of a shampoo, a conditioner, a mask and an oil. In another aspect, the presently claimed invention is directed to a process for manufacturing a bottle as described herein comprising at least the step of (A) coextruding and blowing the inner layer, the intermediate layer and the outer layer each as described herein into a mold to obtain the bottle as described herein.

The body of the bottle extends between the bottom and the shoulder which is connected to the neck. In one embodiment, the neck is manufactured in combination with the body during coextrusion and then blown into a mold. The neck is not attached to the body after coextrusion of the body. The bottom is formed by welding (or pinching) a tube which is manufactured by coextrusion before blowing.

The thickness of the extrusion head is preferably adapted to provide for the desired predetermined wall thickness of the bottle including, e.g., a greater thickness of the intermediate layer compared with the outer layer and inner layer, respectively. The method according to the presently claimed invention allows for the simultaneous production of the body and neck in the same die. Hence, it is not required, as in the case of the manufacture of a tube, to reattach or over-inject a neck onto a body after they have been manufactured. The temperature of the coextrusion head is preferably adjusted depending of the nature of the polyethylene that is being used in order to stabilize the shape of the bottle and maintaining its technical properties and aesthetic appearance.

The presently claimed invention is associated with at least one of the following advantages:

• The bottle according to the presently claimed invention comprising recycled polyethylene has satisfactory mechanical properties compared to a similar bottle that comprises virgin polyethylene exclusively.

• The bottle according to the presently claimed invention has a stress crack resistance > 100 h determined according to DIN 55457-1.

• The bottle can be easily recycled because it exclusively consists of polyethylene.

• The bottle can be labelled easily and is aesthetically appealing to customers.

• The bottle is a cosmetic/food grade bottle.

• The bottle is suitable for housing hair care composition, with a satisfactory product stability and product shelf-life.

Description of the drawings

Fig. 1 shows a bottle according to the presently claimed invention in a schematic and partial longitudinal view.

Fig. 2 shows a cap as described herein in a schematic and partial longitudinal view. Fig. 3 shows a longitudinal view of a wall as described herein.

Reference signs

1 Bottle

2 Body

3 Neck

4 Opening

5 Multilayer wall

6 Intermediate layer

7 Outer layer

8 Inner layer

9 Cap

10 Bottom

11 Shoulder

Embodiments

In the following, there is provided a list of embodiments to further illustrate the present disclosure without intending to limit the disclosure to the specific embodiments listed below.

1 . A bottle (1) comprising a body (2) and a neck (3) surmounting the body (2) and defining an opening (4) of the bottle (1), the body (2) and the neck (3) being formed by a multilayer wall (5) of the bottle (1), the multilayer wall (5) of the bottle (1) comprising at least three superimposed layers comprising at least one intermediate layer (6) interposed between an outer layer (7) and an inner layer (8), characterized in that the intermediate layer (6) comprises recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), the outer layer (7) comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), and the inner layer (8) comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg). 2. The bottle according to embodiment 1 , wherein the intermediate layer (6) comprises recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

3. The bottle according to embodiment 1 or 2, wherein the outer layer (7) comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

4. The bottle according to any one of embodiments 1 to 3, wherein the inner layer (8) comprises high density polyethylene having a melt flow index in the range from > 0.25 to

< 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg),

5. The bottle according to any one of embodiments 1 to 4, wherein the bottle (2) is obtained by a coextrusion-blow-molding process.

6. The bottle according to any one of embodiments 1 to 5, wherein the recycled high density polyethylene has a density in the range from > 0.94 to < 0.96 g/cm³, preferably in the range from > 0.945 to < 0.955 g/cm³.

7. The bottle according to any one of embodiments 1 to 6, wherein the high density polyethylene has a density in the range from > 0.94 to < 0.96 g/cm³, preferably in the range from > 0.950 to < 0.960 g/cm³.

8. The bottle according to any one of embodiments 1 to 7, wherein the high density polyethylene comprised by the inner layer (8) is identical to the high density polyethylene comprised by the outer layer (7).

9. The bottle according to any one of embodiments 1 to 9, wherein the multilayer wall (5) has a thickness in the range from > 0.6 to < 1 .4 mm, preferably in the range from > 0.8 to

< 1.2 mm.

10. The bottle according to any one of embodiments 1 to 10, wherein the thickness of the intermediate layer (6) is in the range from > 30 % to < 60 % of the total thickness of the multilayer wall (5).

11 . The bottle according to any one of embodiments 1 to 10, wherein the thickness of the outer layer (7) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall (5). 12. The bottle according to any one of embodiments 1 to 11 , wherein the thickness of the inner layer (8) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall (5).

13. The bottle according to any one of embodiments 1 to 12, wherein the bottle (1) comprises three superimposed layers.

14. The bottle according to any one of embodiments 1 to 13, wherein at least one of the inner layer (8), the intermediate layer (6) and the outer layer (7) comprises at least one colourant.

15. The bottle according to any one of embodiments 1 to 14, wherein the bottle (1) does not comprise any adhesive layer.

16. The bottle according to any one of embodiments 1 to 15, wherein the bottle (1) has a stress crack resistance > 100 h determined according to DIN 55457-1.

17. The bottle according to any one of embodiments 1 to 16, wherein the bottle (1) has a volume in the range from > 50 mL to < 2000 mL, preferably in the range from > 50 mL to < 1000 mL.

18. A container comprising a bottle (1) according to any one of embodiments 1 to 17 and a cap (9) which is rotatably mounted onto the bottle (1).

19. The container according to embodiment 18, wherein the cap (9) comprises polypropylene.

20. The container according to embodiment 18 or 19, wherein the cap (9) is obtained by injection molding.

21 . The container according to any one of embodiments 18 to 20, wherein the container houses a hair care composition.

22. The container according to embodiment 21 , wherein the hair care composition is selected from the group consisting of a shampoo, a conditioner, a mask and an oil.

23. A process for manufacturing a bottle (1) according to any one of embodiments 1 to 17 comprising at least the step of

(A) coextruding and blowing the inner layer (8), the intermediate layer (6) and the outer layer (7) each defined as in any one of embodiments 1 to 16 into a mold to obtain the bottle (1) according to any one of embodiments 1 to 17.

EXAMPLES

The following examples illustrate the formulations and performance results according to the presently claimed invention. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative compositions and results. These examples are not intended to exclude equivalents and variations of the presently claimed invention, which are apparent to one skilled in the art.

Fig. 1 illustrates a bottle (1) according to the presently claimed invention. The bottle (1) comprises a neck (3) which is adapted to cooperate with a cap (9) to seal it. In the illustrated example the bottle (1) houses a hair care composition. The bottle (1) has a capacity of 250 mL, but the capacity may be varied within the scope of the presently claimed invention.

The bottle (1) can be in part or fully covered by a visible label which allows information about the hair care composition to be transmitted. The label can be fixed to the bottle by using adhesives. The adhesive can be a renewable adhesive which is fully biodegradable and compostable and conforms to European standard EN 13432 and is approved by the FDA. The label can also be fixed by a shrink sleeve or by melting the label onto the bottle (1) during manufacturing. Alternatively, the label can also be molded directly into the material of the bottle (1). The label can optionally comprise layers, e.g., a metallization effect results when a layer is composed of ink/metallization. As another alternative, the label can be directly printed onto the bottle (1).

The bottle (1) comprises a body (2) and a neck (3) defining an opening (4) of the bottle (1). The body (2) has a central portion of general shape, as e.g., a cylindrical shape with a circular section extending along a longitudinal axis. The body (2) has opposite to the neck (3) a bottom (10) which closes the bottle (1). The bottle (1) has a shoulder (11) which connects the body (2) to the neck (3). The neck (3) has external threads which are adapted to cooperate with internal threads of the cap (9) which can be screwed onto the neck (3) of the bottle (1) to close the container.

Fig. 3 illustrates the wall (5) of the bottle (1) comprising three superimposed layers, e.g. an outer layer (7), an inner layer (8) and an intermediate layer (6) which is arranged between the outer layer (7) and the inner layer (8). The inner layer (8) is intended to be in contact with the product which is housed in the bottle (1).

Materials • Polymer 1

Krutene-HD white: a recycled high density polyethylene in the form of pellets, commercially available from Kruschitz GmbH, Austria, with a melt flow index of 0.49 g/10 min according to ISO 1133 (190 °C, 2.16 kg) and a density of 0.950 g/cm³

• Polymer 2

BB2541 : a virgin high density polymer, commercially available from Borealis AG, Austria, with a melt flow index of 0.30 g/10 min according to ISO 1133 (190 °C, 2.16 kg) and a density of 0.954 g/cm³

Example 1.

A bottle was made by implementing the process according to the presently claimed invention. The bottle had a volume of 250 mL. The bottle had a wall thickness of 1.0 mm. The outer layer constituted 25 % of the wall thickness and was made of polymer 2. The inner layer constituted 45 % of the wall thickness and was made of polymer 2. The intermediate layer constituted 30 % of the wall thickness and was made of polymer 1 . Each of the inner, intermediate and outer layer were coloured and a label was directly printed on the bottle.

The bottle was visually intact. The bottle was filled and capped and showed no breakage or decapping after subsequently dropping from 1 .5 height. The bottle was filled with a standard liquid and capped and passed environmental stress crack resistance at 40 °C for 3 months determined according to DIN 55457-1.

Example 2.

A bottle was made by implementing the process according to the presently claimed invention. The bottle had a volume of 250 mL. The bottle had a wall thickness of 1.0 mm. The outer layer constituted 25 % of the wall thickness and was made of polymer 2. The inner layer constituted 25 % of the wall thickness and was made of polymer 2. The intermediate layer constituted 50 % of the wall thickness and was made of polymer 1 . Each of the inner, intermediate, and outer layer were coloured and a label was directly printed on the bottle.

Bottles comprising walls made of recycled polyethylene are not stable. The examples show that the incorporation of a thin layer of virgin polyethylene into the wall of a bottle that is otherwise made of recycled polyethylene increased its stability and lead to stable bottles that were suitable for commercial application.

Claims

1 . A bottle (1) comprising a body (2) and a neck (3) surmounting the body (2) and defining an opening (4) of the bottle (1), the body (2) and the neck (3) being formed by a multilayer wall (5) of the bottle (1), the multilayer wall (5) of the bottle (1) comprising at least three superimposed layers comprising at least one intermediate layer (6) interposed between an outer layer (7) and an inner layer (8), characterized in that the intermediate layer (6) comprises recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), the outer layer (7) comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.40 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg), and the inner layer (8) comprises high density polyethylene having a melt flow index in the range from > 0.20 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

2. The bottle according to claim 1 , wherein the intermediate layer (6) comprises recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

3. The bottle according to claim 1 or 2, wherein the outer layer (7) comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg) or recycled high density polyethylene having a melt flow index in the range from > 0.45 to < 0.85 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg).

4. The bottle according to any one of claims 1 to 3, wherein the inner layer (8) comprises high density polyethylene having a melt flow index in the range from > 0.25 to < 0.35 g/10 min determined according to ISO 1133 (190 °C, 2.16 kg),

5. The bottle according to any one of claims 1 to 4, wherein the recycled high density polyethylene has a density in the range from > 0.94 to < 0.96 g/cm³, preferably in the range from > 0.945 to < 0.955 g/cm³. The bottle according to any one of claims 1 to 5, wherein the high density polyethylene has a density in the range from > 0.94 to < 0.96 g/cm³, preferably in the range from > 0.950 to < 0.960 g/cm³. The bottle according to any one of claims 1 to 6, wherein the high density polyethylene comprised by the inner layer (8) is identical to the high density polyethylene comprised by the outer layer (7). The bottle according to any one of claims 1 to 7, wherein the multilayer wall (5) has a thickness in the range from > 0.6 to < 1 .4 mm, preferably in the range from > 0.8 to < 1.2 mm. The bottle according to any one of claims 1 to 8, wherein the thickness of the intermediate layer (6) is in the range from > 30 % to < 60 % of the total thickness of the multilayer wall (5). The bottle according to any one of claims 1 to 9, wherein the thickness of the outer layer (7) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall (5). The bottle according to any one of claims 1 to 10, wherein the thickness of the inner layer (8) is in the range from > 20 % to < 40 % of the total thickness of the multilayer wall (5). The bottle according to any one of claims 1 to 11 , wherein the bottle (1) has a stress crack resistance > 100 h determined according to DIN 55457-1. A container comprising a bottle (1) according to any one of claims 1 to 12 and a cap (9) which is rotatably mounted onto the bottle (1). The container according to claim 13, wherein the container houses a hair care composition. A process for manufacturing a bottle (1) according to any one of claims 1 to 12 comprising at least the step of

(A) coextruding and blowing the inner layer (8), the intermediate layer (6) and the outer layer (7) each defined as in any one of claims 1 to 16 into a mold to obtain the bottle (1) according to any one of claims 1 to 12.