Polyhydroxyalkanoate-based capsule for beverage preparation

Abstract

The present invention relates to a capsule (1) for preparing a beverage, said capsule comprising an enclosure (2) comprising at least one side wall (4) having a circular rim (5), characterized in that the side wall and the circular rim are formed by injection molding or by thermoforming at least one formulation comprising: (i) at least one polymer P1 chosen from polyhydroxyalkanoates (PHA); and (ii) at least one polymer P2 chosen from polyhydroxyalkanoate (PHA), said polymer P1 having a degree of crystallinity (Kc1) greater than or equal to 50%, and said polymer P2 having a degree of crystallinity (Kc2) less than or equal to 30%, preferably less than or equal to 5%. Abstract figure: Fig. 1

Description

Title of the invention: Capsule based on polyhydroxyalkanoate for the preparation of beverages TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of closed biodegradable and compostable capsules, by industrial composting and / or by domestic or methanizable composting for single use, containing at least one edible substance. The edible substance may be in powder form for the preparation of a beverage, for example coffee, intended to be extracted under pressure or temperature, or in liquid form for the preparation of a beverage, for example lemonade or food supplements, intended to be extracted at low pressure and low temperature or room temperature. STATE OF THE ART

[0002] Pre-measured and pre-packaged portions of coffee are widely used for preparing espresso-type coffees because they are simple and easy to use.

[0003] There are generally two types of capsules on the market, rigid capsules typically consisting of a container and a cover and flexible capsules containing filter layers. The present invention is aimed at the first category of capsule.

[0004] Rigid capsules of the Nespresso® type are widely used in Europe. These capsules comprise a body or container and a seal which are traditionally made essentially of aluminum.

[0005] The process of delivering the final beverage follows the following pattern: a fluid, such as water or milk, is injected into the capsule to interact with the substance contained in the capsule to produce the desired beverage, and when a sufficient amount of fluid fills the capsule, the latter opens under the pressure of the fluid to release the prepared beverage.

[0006] For example, opening the capsule may be accomplished by pressing an extraction face of the capsule with a force effected by increasing the pressure of the fluid inside the capsule against an opening structure provided in the capsule holder so that the extraction face is torn when it reaches a breaking stress thereof. The opening structure may be a number of raised and recessed elements, for example pyramidal elements, over which the extraction face extends and tears under the effect of the internal pressure of the fluid. Such a pressure-controlled beverage preparation has the advantage of being able to produce a high-quality beverage.

[0007] There are also capsules whose lid and body are made of plastic materials.

[0008] Application WO2021 / 239982A1 in the name of the applicant describes a closed capsule whose bottom, side wall and circular rim are formed by injection molding at least one formulation comprising:

[0009] (i) at least one polymer chosen from polyhydroxybutyrates, and

[0010] (ii) at least one ingredient chosen from silicates, vitamins E, plasticized animal or vegetable proteins, or mixtures thereof.

[0011] Prior art capsules that use thermoplastic materials may have the disadvantage of being fragile and may sometimes break during the manufacturing process or during use even though they have a very good barrier function to oxygen and / or water vapor. It has been found in the prior art that during the manufacture of crystalline polyhydroxyalkanoate (PHA) capsules, a large variation in the mechanical properties of the capsule was obtained due to the poor thermal stability of PHA. These prior art capsules may also deform and / or break when subjected to temperature stresses.

[0012] The applicant has therefore developed a new capsule which makes it possible to overcome the problems of the prior art while retaining the good barrier function to oxygen and / or water vapor.

[0013] It is therefore an object of the present invention to provide capsules which are rigid but not brittle while having a good barrier function to oxygen and water vapor and while ensuring constant mechanical characteristics, good temperature resistance, both during their use in an extraction machine and during their manufacture while reducing production defects. These capsules are also biodegradable by industrial composting and / or by domestic composting or even methanizable, and make it possible to prepare a beverage, such as a coffee, of satisfactory quality, when they are used in an espresso type machine, in particular a Nespresso® machine. Summary of the invention

[0014] More specifically, the present invention relates to a capsule for preparing a beverage, said capsule comprising an enclosure comprising at least one side wall having a circular rim, the side wall and the circular rim being formed by injection molding or by thermoforming at least one formulation comprising:

[0015] (i) at least one PI polymer chosen from polyhydroxyalkanoates (PHA); and

[0016] (ii) at least one polymer P2 chosen from polyhydroxyalkanoate (PHA),

[0017] said polymer PI having a degree of crystallinity (Kcl) greater than or equal to 50%,

[0018] and said polymer P2 having a degree of crystallinity (Kc2) less than or equal to 30%, preferably less than or equal to 5%.

[0019] According to one embodiment, the capsule has one or more of the following characteristics:

[0020] - said polyhydroxyalkanoates are chosen from polyhydroxy- polymers butyrate (PHB), preferably polymer PI and / or polymer P2 are PHB copolymers, and / or

[0021] - the polymer PI contains monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from hydroxyvalerate HV, 3-hydroxyhexanoate HH or 4hydroxy-butyrate 4HB, Mla being different from Mlb, and / or the polymer P2 contains monomeric units M2a of hydroxybutyrates 3HB and monomeric units M2b chosen from hydroxyvalerate HV, 3-hydroxyhexanoate HH or 4hydroxy-butyrate 4HB, M2a being different from M2b, preferably the mass ratio Mlb / Mla is less than or equal to 0.07, preferably less than or equal to 0.6 and / or the mass ratio M2b / M2a is greater than or equal to 0.05, preferably ranges from 0.1 to 1, more preferably from 0.2 to 0.9, and / or

[0022] - the polymer PI and / or the polymer P2 are obtained by aerobic fermentation engineering and / or anaerobic in a bio-sourced manner and / or

[0023] - the polymer(s) PI represent from 70 to 99% by weight, preferably from 80 to 98% by weight of the total weight of polymers PI and P2 and / or the polymer(s) P2 represent from 1 to 30% by weight, preferably from 2 to 20% by weight, more preferably from 3 to 10% by weight, of the total weight of polymers PI and P2, and / or

[0024] - the formulation comprises from 50 to 99.9% by weight, preferably from 75 to 99.5% by weight, advantageously from 90 to 99% by weight, of polymer(s) PI and P2, relative to the total weight of the formulation, and / or

[0025] - the formulation further comprises at least one mineral or organic filler, preferably in a proportion ranging from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, preferably said filler is chosen from silica, silicates, laminar double hydroxides (LDH), titanium oxide, vitamin E, plasticized animal or vegetable proteins, or mixtures thereof, relative to the total weight of the formulation, and / or

[0026] - the BET specific surface area of ​​silicates is between 1 and 250m2 / g and / or the median diameter of silicates is between 0.5 and 20qm and / or the dimensional form factor of silicates is greater than or equal to 1:2, and / or

[0027] - the formulation further comprises at least one polyvinyl or ethylene alcohol vinyl, preferably in an amount ranging from 1 to 30% by weight, preferably from 2 to 20% by weight, advantageously from 5 to 10% by weight, relative to the total weight of the formulation, and / or

[0028] - said capsule: - is biodegradable and / or compostable in industrial or domestic conditions or by methanization and / or - contains at least 80% by weight of bio-sourced carbon, relative to the total weight of carbon atoms in the capsule, and / or

[0029] - the enclosure has a bottom and the bottom, the side wall and the circular rim are formed by injection molding or thermoforming, preferably in a single layer of said formulation in a mold, and / or

[0030] - the capsule contains a substance in powder or liquid form, said capsule comprising a seal welded around the edge of the enclosure, preferably the seal comprises a single-layer or multi-layer film, said film comprising one or more materials chosen from materials which are biodegradable and compostable according to an aerobic biological process and / or methanizable according to an anaerobic biological process, preferably the material is chosen from paper, non-wovens, cellulose, SiOx layers, polymers based on polylactic acid, polyhydroxyalkanoates, hybrid layers of organic polymer and inorganic fibers, layers coated with polyvinyl alcohol or copolymer of ethylene and vinyl alcohol, metallized layers preferably using aluminum, these layers of materials being optionally separated by a layer of glue, and / or

[0031] - the cover is made of a multilayer film comprising: (i) a film of paper or filter paper, ii) a barrier layer, preferably the barrier layer comprising one or more layers chosen from: - a hybrid barrier layer comprising an organic polymer and inorganic compounds, and / or - a SiOx barrier layer, and / or - a cellulose barrier layer,

[0032] iii) a layer of non-woven fabric, said layer of non-woven fabric being inside the capsule, and / or

[0033] - the cover is made of a multilayer film comprising:

[0034] i) a barrier layer,

[0035] ii) a film based on biopolymers such as polyhydroxyalkanoates PHA or polybutylenadipate-terephthalate PBAT or polybutylensuccinate PBS or polybutylene-co aliphate co-terephthalate PB AIT or polylactic acids PLA,

[0036] Or a multilayer film comprising:

[0037] i) a film based on biopolymers such as polyhydroxyalkanoates PHA or polybutylenadipate-terephthalate PBAT or polybutylensuccinate PBS or poly- butylene-co aliphate co-terephthalate PB AIT or polylactic acids PLA,

[0038] ii) a barrier layer,

[0039] iii) a film based on biopolymers such as polyhydroxyalkanoates PHA or polybutylene co-adipate co-terephthalate PBAT or polybutylene succinate PBS or polybutylene co-aliphate-co terephthalate PBA1T or polylactic acids PLA.

[0040] The invention further relates to a method of manufacturing a capsule according to the invention, said method comprising the following steps: a. Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded, b. injection molding the formulation obtained in step a) into a mold to form a layer of at least the side wall and the circular rim of the enclosure, optionally one or more layers of the enclosure may be injection molded, using a formulation different from the formulation of step a), c. filling the enclosure with the substance in powder or liquid form, if the base is not injection molded from the formulation, then the filling step is preceded by a step of placing a single-layer or multi-layer base in order to form the enclosure, d. possibly, closing the enclosure using the cover to form the capsule,

[0041] Or comprising the following steps: a. Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded, b. Manufacture of plates or a film by extrusion of the formulation before calendering or blowing, optionally manufacture of one or more other layers of at least the side wall and the circular rim of the enclosure by extrusion using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation, c. Shaping by thermoforming the plate or film into a suitable shape, d. filling the enclosure with the substance in powder or liquid form, if the base is not shaped by thermoforming during step c), then the filling step is preceded by a step of placing a single-layer or multi-layer base in order to form the enclosure, e. possibly, closing the enclosure using the seal to form the capsule.

[0042] The capsules according to the invention typically comprise at least 60% by weight of bio-sourced carbon. The bio-sourced carbon content can be determined according to EN 16640. According to this standard, the total carbon fraction for the capsule must be determined and, within this, the bio-sourced portion must be measured, expressed as a % (measurement of C14 using the radiocarbon method).

[0043] Advantageously, a capsule according to the invention comprises at least 80% by weight of biosourced carbon, preferably at least 90% by weight of biosourced carbon, relative to the total weight of the carbon atoms of the capsule.

[0044] The capsules according to the invention are stable during storage. Since they have good oxygen and water vapor tightness, they can be stored and retain their contents for at least 12 months before being consumed.

[0045] The capsules according to the invention are compatible with Nespresso® machines. The present invention is applicable to other common machine formats.

[0046] The capsules according to the invention have a barrier function, that is to say that they typically have an oxygen permeability of less than 3.5 x 103 cm3 / capsule / 24hrs at 0.21 atm at 23°C and 50% RH (relative humidity), preferably equal to or less than 3.0 x 103 cm3 / capsule / 24hrs at 0.21 atm at 23°C and 50% RH, more preferably equal to or less than 2.90 x 103 cm3 / capsule / 24hrs at 0.21 atm at 23°C and 50% RH, measured according to the ASTM F1307 or ISO 15105-2 standard.

[0047] Furthermore, the capsules according to the invention are biodegradable, by industrial composting and / or by domestic composting, advantageously they are compostable both by industrial composting and by domestic composting.

[0048] Thus, the capsules according to the invention have both a very satisfactory barrier function to gases, in particular to oxygen, and good mechanical and thermal properties, since they are sufficiently rigid without being brittle while ensuring constant quality during their manufacture and use.

[0049] Other characteristics, variants and advantages of the implementation of the invention will become more apparent upon reading the description and examples which follow, given for illustrative and non-limiting purposes of the invention. BRIEF DESCRIPTION OF THE FIGURES

[0050] [Fig.l] is a schematic cross-sectional view of an enclosure implemented according to the invention.

[0051] [Fig.2] is a schematic cross-sectional view of a capsule implemented according to the invention.

[0052] [Fig.3] is a graph representing the flows of different formulations and polymers as a function of time. DETAILED DESCRIPTION OF THE INVENTION

[0053] The present invention relates to a sealed capsule in the form of an individual portion individual containing at least one edible substance in powder or liquid form, for the preparation of a beverage, suitable for being extracted under pressure, the beverage being able to be for example coffee, tea, chocolate, lemonade or a food supplement.

[0054] Preferably, the invention relates to a capsule for preparing a beverage, the capsule comprising an enclosure comprising at least one side wall having a circular rim and a bottom. The capsule is intended to be extracted under pressure and contains a substance in powder or liquid form for preparing a beverage.

[0055] According to one embodiment, the capsule further comprises a cover located opposite the bottom of this capsule.

[0056] According to a first variant, the bottom is configured to be perforated by blades of the coffee production machine so that the blades provide openings for the injection of fluid. In this case, the bottom forms an injection wall through which the fluid is injected and the latter will exit after passing through the substance contained in the capsule through the seal.

[0057] According to a second variant, the capsule is crossed by the blades of the coffee production machine at the level of the cover which here serves as an injection wall and the fluid which is injected there exits through the bottom.

[0058] According to the invention, the side wall and the circular rim are formed by injection molding or by thermoforming at least one formulation according to the invention.

[0059] According to a first embodiment, the side wall, the circular rim and the bottom are formed by injection molding or by thermoforming at least one formulation according to the invention and the lid is formed by a single-layer or multi-layer film.

[0060] According to a second embodiment, the base and the lid are formed by a single-layer or multi-layer film. In this case, during the injection molding or thermoforming of at least one formulation according to the invention, in addition to the side wall and the circular rim, a support may also be formed, this support may be used to support the base formed by a single-layer or multi-layer film. This support may have, for example, a cross-shaped structure and will then be obtained during the injection molding or thermoforming of at least one formulation according to the invention.

[0061] In the case of a substance in powder form, the extraction of the beverage can be carried out at a pressure ranging from 2 to 20 bars, and for example at a temperature ranging from 30 to 100°C.

[0062] In the case of a substance in liquid form, the extraction of the beverage can be carried out at a pressure ranging from 2 to 7 bars, and for example at room temperature or at a temperature ranging from 20 to 45°C.

[0063] According to the invention, the formulation of the capsule comprises:

[0064] (i) at least one first PI polymer chosen from PHAs; and

[0065] (ii) at least one second polymer P2 chosen from PHAs,

[0066] said PI polymer having a degree of crystallinity (Kcl) greater than or equal to 50% and

[0067] said polymer P2 having a crystallinity rate (Kc2) less than or equal to 30%, before preferably less than or equal to 15%, even more preferably less than or equal to 5%.

[0068] As described above, the capsule is typically adapted to be opened on protruding elements under the effect of the pressure increase when a fluid is injected therein into a capsule holder system or, for other systems, for an outlet opening created by mechanical perforation of the membrane or the bottom by points.

[0069] Preferably, the capsule according to the invention is made up of at least 85% by weight of biodegradable and compostable materials (aerobic biological process) and / or methanizable materials (anaerobic biological process), preferably 100% of biodegradable and compostable materials (aerobic biological process) and / or methanizable materials (anaerobic biological process).

[0070] By "biodegradable" is meant a material capable of decomposing under the action of living organisms, such as bacteria, fungi or algae, to transform for example into carbon dioxide, water and / or methane.

[0071] By “compostable” we mean an object made with a biodegradable material capable of disintegrating under controlled conditions such as, for example, those defined by industrial and domestic compostability standards.

[0072] The capsules according to the invention advantageously meet the compostability standard EN 13432, they are then said to be biodegradable under industrial composting conditions.

[0073] The EN 13432 standard specifies the technical requirements and procedures for determining the compostability of a material.

[0074] The EN 13432 standard defines the characteristics that a material, a product, must possess to be considered compostable and biodegradable.

[0075] Biodegradation can be tested according to standards such as ISO 14855, ISO 17556 or ISO 14851. For example, one of these tests requires that, to be considered "industrially compostable" - at least 90% of the material must be biologically degraded under controlled conditions within six months.

[0076] Similar tests also exist to enable certification of home composting. There are currently no international or European standards, only national standards for home composting. Thus, the capsules according to the invention are biodegradable under home composting conditions. according to French recommendations. In particular, they meet the NF T51-800 (2015) standard, namely that at least 90% of the capsule is biologically degraded under controlled conditions in less than 365 days (maximum 12 months) at 25°C + / -5°C. The capsules according to the invention will also typically meet the Australian standard AS 5810 (2010).

[0077] The capsule according to the invention thus typically comprises an enclosure and a seal welded around the edge of the enclosure. The enclosure thus comprises a bottom and a side wall having a circular edge. The circular edge makes it possible to hold the capsule when it is inserted into a machine and to create a sealing zone when it is used in said machine, such as a coffee machine.

[0078] The capsule enclosure is typically shaped by molding or thermoforming the bottom, sidewall, and circular rim in one piece from a formulation. This molding or thermoforming in one piece may be performed in one or more layers, with the understanding that at least one layer is made of the formulation described in the invention. When two layers are used, typically each layer will be made of a different formulation. For example, if the enclosure is molded in two layers, it could be a layer of the formulation of the invention and a barrier layer made, for example, of polyvinyl alcohol (PVOH) or ethylene vinyl alcohol (EVOH).

[0079] When three layers are involved, typically, they may be at least two different layers, at least one of which will be made up of the formulation of the invention. One of the three layers may then be a barrier layer made up, for example, of PVOH or EVOH.

[0080] According to a preferred embodiment, the molding of the enclosure is carried out in a single layer of the formulation.

[0081] According to the invention, the formulation of the capsule comprises:

[0082] (i) at least one first PI polymer chosen from PHAs; and

[0083] (ii) at least one second polymer P2 chosen from PHAs,

[0084] said PI polymer having a degree of crystallinity (Kcl) greater than or equal to 50% and

[0085] said polymer P2 having a crystallinity rate (Kc2) less than or equal to 30%, aven- preferably less than or equal to 15%, even more preferably less than or equal to 5%.

[0086] Therefore, PI is rather crystalline while P2 is rather weakly crystalline or even rather amorphous.

[0087] The inventors have thus discovered that the effectiveness of the barrier layer to oxygen and / or water vapor and the flexibility of a capsule result from the nature of the additives as well as the crystallinity of the polymer used, in particular when it is a polymer from the polyhydroxyalkanoate (PHA) family.

[0088] The inventors discovered that the properties of the capsules were influenced by the degree of crystallization of their formulations. Thus, the higher the degree of crystallization, the more fragile the molded part will be.

[0089] Crystallinity refers to the degree of structural order in a solid and is related to the order of the polymer's molecular chains.

[0090] The degree of crystallinity can be measured by Differential Thermal Analysis or DTA or by Differential Scanning Calorimetry or DSC (Differential Scanning Calorimetry in English), preferably it will be measured by DSC. They make it possible to determine in particular the glass transition temperature called Tg, the crystallization temperature called Te and the melting temperature called Tm of the polymer.

[0091] Completely amorphous polymers have neither a crystallization temperature nor a melting temperature, and are thermally characterized by DSC only by their glass transition temperature Tg.

[0092] The properties of plastics are strongly influenced by their degree of crystallization. The higher the degree of crystallization, the stiffer a molded part will be, but also the more brittle it will be. The degree of crystallization (also called crystallinity rate) is influenced by the chemical structure and thermal history, such as cooling conditions during manufacturing or post-thermal processing.

[0093] For the determination of the degree of crystallization Kc of the polymer Pi, the enthalpy of fusion measured by DSC(AHmes) of the polymer Pi is compared to the literature value (AHlit) for a completely crystalline polymer.

[0094] Thus,

[0095] [Math 1] Kc = AHmes / AHlit.

[0096] There are databases in the literature, in particular scientific articles describing the enthalpy of fusion of various completely crystalline polymers. Thus, the person skilled in the art has access to the enthalpy of fusion of completely crystalline polymers, in particular those of the PHA type, in particular of the PHB type.

[0097] The fusion enthalpy AHlit of a completely crystalline PHBH or PHBV type PHB polymer is 146J / g as reported in Vorleak Chea et al. J. APPL. POLYM. SCI. 2015, DOI: 10.1002 / APP.41850 or in Zonglin Li et al. Polymers 2020, 12, 1300; doi:10.3390 / polyml2061300 or in Sunny Modi et al. European Polymer Journal 47 (2011) 179 - 186.

[0098] For an amorphous polymer, there is no melting peak, so the enthalpy of fusion will be zero. For example, the enthalpy of fusion of a P3HB4HB type polymer is close to zero.

[0099] The degree of crystallinity has a significant influence on hardness, density, transparency and diffusion, hence the gas barrier properties.

[0100] By “polymer” is meant in the present application a homopolymer and / or a copolymer.

[0101] The PI polymer is a rather crystalline polymer. The formulation according to the invention may comprise one or more crystalline PI polymers.

[0102] By “rather crystalline” polymer, it is understood by the present invention that the polymer has a degree of crystallinity Kcl greater than or equal to 50%.

[0103] The polymer P2 is a weakly crystalline or even rather amorphous polymer. The formulation according to the invention may comprise one or more weakly crystalline or even amorphous polymers P2.

[0104] By “low crystalline” polymer, it is understood by the present invention that the polymer has a degree of crystallinity Kc2 ranging from 5% to 49%.

[0105] By “rather amorphous” polymer, it is understood by the present invention that the polymer has a degree of crystallinity Kc2 less than or equal to 5%.

[0106] The rather crystalline polymer PI has a melting temperature. When the polymer P2 is amorphous, it does not have a melting temperature.

[0107] According to one embodiment, the glass transition temperature Tg of the crystalline polymers PI used in the invention is greater than -10°C, preferably ranging from -5 to 5°C (measured by DSC with a temperature ramp of +10°C / min).

[0108] According to one embodiment, the glass transition temperature Tg of the amorphous polymers P2 used in the invention is less than -10°C, preferably ranges from -20°C to -10°C (measured in DSC with a temperature ramp of +10°C / min).

[0109] According to one embodiment, the melting temperature of the crystalline polymers PI used according to the invention ranges from 120°C to 200°C (measured by DSC with a temperature ramp of +10°C / min).

[0110] According to one embodiment of the invention, the formulation comprises silica (SiO2) and / or titanium dioxide (TiO2). SiO2 and / or TiO2 play a role in the barrier function but are also nucleating agents. Silica (SiO2) has a particle size strictly greater than 100 nm, more preferably strictly less than 500 nm. TiO2 has a particle size strictly greater than 460 nm, more preferably strictly greater than 460 nm and strictly less than 3900 nm.

[0111] By “particle size” is meant the median diameter measured for example by laser granulometry.

[0112] Typically, all ingredients of the formulation are biodegradable.

[0113] According to one embodiment, the PHAs are chosen from polymers of the PHB (poly(hydroxybutyrate)) family.

[0114] In the context of the present invention, a “polymer of the PHB family” designates a polymer comprising at least one repeating unit of formula -(O-CH(CH3)-CH2CO)-.

[0115] According to one embodiment, the PHAs are chosen from poly3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH) polymers, polyhydroxy-butyrate / hydroxyvalerate (PHBV) polymers, poly3-hydroxybutyrate 4-hydroxybutyrate (P3HB4HB) polymers, and mixtures thereof.

[0116] The PHBH polymer comprises 3-hydroxybutyrate (3HB) monomeric units and 3-hydroxyhexanoate (3HH) monomeric units.

[0117] The monomeric unit 3HB corresponds to the formula (1):

[0118] [Chem.l]

[0119] The monomeric unit 3HH corresponds to the formula (2):

[0120] [Chem.2]

[0121] The PHBV polymer comprises 3-hydroxybutyrate (3HB) monomeric units and hydroxyvalerate (HV) monomeric units.

[0122] The monomeric unit HV corresponds to the formula (3):

[0123] [Chem.3]

[0124] The polymer P3HB4HB comprises 3-hydroxybutyrate (3HB) monomeric units and 4-hydroxybutyrate (4HB) monomeric units.

[0125] The monomeric unit 4HB corresponds to the formula (4):

[0126] [Chem.4]

[0127] Preferably, in the formulation according to the invention, when present, the PHBV polymer is a rather crystalline polymer and when present, PHBH and P3HB4HB polymers are weakly crystalline or even amorphous polymers.

[0128] According to one embodiment, the polymer PI is a polymer obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0129] According to one embodiment, the polymer PI contains monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from either hydroxyvalerate HV or 3-hydroxyhexanoate HH or 4hydroxybutyrate 4HB, Mla being different from Mlb.

[0130] Preferably, the monomeric units Mlb represent less than 5% by weight, preferably less than 3% by weight, or even less than 1% by weight, of the total weight of the monomeric units Mla and Mlb.

[0131] According to one embodiment, the polymer P2 is a polymer obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0132] According to one embodiment, the polymer P2 contains monomeric units M2a of hydroxybutyrates 3HB and monomeric units M2b chosen from either hydroxyvalerate HV or 3-hydroxyhexanoate HH or 4hydroxy-butyrate 4HB, M2a being different from M2b.

[0133] Preferably, the monomeric units M2b represent at least 5% by weight, preferably at least 20% by weight, or even at least 30% by weight, of the total weight of the monomeric units M2a and M2b.

[0134] According to one embodiment, the mass ratio Mlb / Mla is less than or equal to 0.07, preferably less than or equal to 0.6 and / or the mass ratio M2b / M2a is greater than or equal to 0.05, preferably ranging from 0.1 to 1, more preferably from 0.2 to 0.9.

[0135] Preferably, the polymers PI and P2 do not comprise monomeric units different from the PHAs, preferably the polymers PI and P2 do not comprise monomeric units different from the monomeric units originating from Mla, Mlb, M2a and M2b, respectively.

[0136] Polymers PI and P2 are commercially available or can be prepared according to methods known to those skilled in the art.

[0137] According to one embodiment, the polymer(s) PI represent from 70 to 99% by weight, preferably from 80 to 98% by weight, more preferably from 85 to 97% by weight, of the total weight of the polymers PI and P2.

[0138] According to one embodiment, the polymer(s) P2 represent from 1 to 30% by weight, preferably from 2 to 20% by weight, more preferably from 3 to 15% by weight, of the total weight of the polymers PI and P2.

[0139] According to one embodiment, the formulation comprises from 50 to 99.9% by weight, preferably from 75 to 99.5% by weight, advantageously from 90 to 99% by weight, of polymer(s) PI and P2, relative to the total weight of the formulation, PI and P2 preferably being chosen from PHBV polymers and P3HB4HB polymers, the PHBV polymer preferably being a crystalline polymer and the P3HB4BH polymer preferably being an amorphous polymer.

[0140] According to one embodiment, the formulation further comprises (iii) at least one mineral or organic filler, preferably chosen from silica, silicates, vitamins (preferably vitamin E), peroxides, vegetable or animal waxes, plasticized animal or vegetable proteins, or mixtures thereof, preferably from silica, silicates, vitamin E, plasticized animal or vegetable proteins, or mixtures thereof.

[0141] The mineral or organic filler(s) may represent, for example, from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of the total weight of the formulation.

[0142] According to one embodiment, the silicates are chosen from aluminum silicates, aluminum and magnesium silicates, preferably from aluminum silicates or even HDL (lamellar double hydroxides).

[0143] Among the aluminum and magnesium silicates, montmorillonites can be mentioned.

[0144] According to one embodiment, the silicates are chosen from phyllosilicates, preferably aluminum phyllosilicates.

[0145] According to one embodiment, the phyllosilicates are chosen from kaolinites, halloysites, and their mixture.

[0146] According to one embodiment, the aluminum silicates are kaolins.

[0147] According to one embodiment, the silicates, preferably the aluminum silicates, have a particle size with a median diameter measured by laser granulometry ranging from 0.5 pm to 20 pm, and / or a specific surface area (measured by the Brunauer, Emmett and Teller method known as BET) ranging from 1 to 250 m2 / g.

[0148] Typically, these silicates have dimensional form factors greater than or equal to 1:2, advantageously greater than or equal to 1:4, and particularly greater than or equal to 1:6, in which case we can speak of an acicular form. The form factor can be determined by microscopy, for example by scanning electron microscopy (SEM). These acicular charges are preferentially oriented during injection of the capsule in the direction of flow, and consequently, parallel to the surface of the walls of the capsule and allow: - mechanical reinforcement in the longitudinal direction (less crushing of the capsule), and - an increase in the tortuosity of the polymer matrix brought about by the presence of acicular-shaped particles providing an additional barrier effect

[0149] According to one embodiment, the silicates, typically of acicular form, will have one or even two nanometric dimensions (from 1 nm to 100 nm), it being understood that these silicates comprise at least one micrometric dimension (from 1 pm to less 1 mm), in order to comply with food contact standards. This nano / micro dimensioning will allow the introduction of a lower quantity of silicates, compared to a micrometric carbonate or talc and has at least 2 advantages:

[0150] - a reduction in weight of the finished part, while improving the O2 barrier effect of the matter

[0151] - an increase in the capsule stress resistance as well as the modulus de Young.

[0152] According to one embodiment, the formulation comprises: • from 50 to 99.9% by weight, preferably from 75 to 99.5% by weight, advantageously from 90 to 99% by weight, of polymer(s) PI and P2, • from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of ingredient(s) chosen from silicates, vitamin E, plasticized vegetable or animal proteins, or mixtures thereof,

[0153] relative to the total weight of the formulation.

[0154] According to one embodiment, the formulation comprises: • from 50 to 99.9% by weight, preferably from 75 to 99.5% by weight, advantageously from 90 to 99% by weight, of polymer(s) PI and P2, • from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of ingredient(s) chosen from silicates, vitamin E, or their mixtures,

[0155] relative to the total weight of the formulation.

[0156] According to one embodiment, the formulation comprises: i. from 50 to 98% by weight, preferably from 75 to 95% by weight, advantageously from 80 to 90% by weight, of PI polymer(s), ii. from 0.5 to 20% by weight, preferably from 1 to 15% by weight, advantageously from 2 to 10% by weight, of polymer(s) P2, iii. from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of mineral or organic fillers,

[0157] relative to the total weight of the formulation.

[0158] According to one embodiment, the formulation comprises: i. from 50 to 98% by weight, preferably from 75 to 95% by weight, advantageously from 80 to 90% by weight, of polymer(s) PI, PI comprising monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), ii. from 0.5 to 20% by weight, preferably from 1 to 15% by weight, advantageously from 2 to 10% by weight, of polymer(s) P2, P2 comprising mono units M2a hydroxybutyrate (3HB) monomeric units and M2b monomeric units selected from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), iii. from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of mineral or organic fillers,

[0159] relative to the total weight of the formulation,

[0160] PI and P2 being advantageously obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0161] According to one embodiment, the formulation comprises: i. from 50 to 98% by weight, preferably from 75 to 95% by weight, advantageously from 80 to 90% by weight, of PI polymer(s), ii. from 0.5 to 20% by weight, preferably from 1 to 15% by weight, advantageously from 2 to 10% by weight, of polymer(s) P2, iii. from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of mineral or organic fillers chosen from silicates, vitamin E, or mixtures thereof,

[0162] relative to the total weight of the formulation.

[0163] According to one embodiment, the formulation comprises, relative to the total weight of the formulation: i. from 50 to 98% by weight, preferably from 75 to 95% by weight, advantageously from 80 to 90% by weight, of polymer(s) PI, PI comprising monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), the monomer Mlb representing less than 5% by weight, preferably less than 3% by weight, or even less than 1% by weight, of the total weight of the monomers Mla and Mlb, ii. from 0.5 to 20% by weight, preferably from 1 to 15% by weight, advantageously from 2 to 10% by weight, of polymer(s) P2, P2 comprising monomeric units M2a of hydroxybutyrate (3HB) and monomeric units M2b chosen from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), the monomer M2b representing at least 5% by weight, preferably at least 20% by weight, or even at least 30% by weight, of the total weight of the monomers M2a and M2b, iii. from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of mineral or organic fillers or organic fillers chosen from silicates, vitamin E, or mixtures thereof,

[0164] PI and P2 being advantageously obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0165] According to one embodiment, the formulation comprises, relative to the total weight of the formulation: i. from 50 to 98% by weight, preferably from 75 to 95% by weight, advantageously from 80 to 90% by weight, of polymer(s) PI, PI comprising monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), the monomer Mlb representing less than 5% by weight, preferably less than 3% by weight, or even less than 1% by weight, of the total weight of the monomers Mla and Mlb, ii. from 0.5 to 20% by weight, preferably from 1 to 15% by weight, advantageously from 2 to 10% by weight, of polymer(s) P2, P2 comprising monomeric units M2a of hydroxybutyrate (3HB) and monomeric units M2b chosen from either hydroxyvalerate (HV) or 3-hydroxyhexanoate (HH) or 4hydroxy-butyrate (4HB), the monomer M2b representing at least 5% by weight, preferably at least 20% by weight, or even at least 30% by weight, of the total weight of the monomers M2a and M2b, iii. from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of aluminum silicates,

[0166] relative to the total weight of the formulation,

[0167] PI and P2 being advantageously obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0168] According to one embodiment, the formulation comprises: • from 50 to 98.9% by weight, preferably from 75 to 97.5% by weight, advantageously from 80 to 94% by weight, of polymer(s) chosen from PHBV polymers and P3HB4HB polymers, the PHBV polymer being a rather crystalline polymer and the P3HB4BH polymer being a rather amorphous polymer, • from 0.1 to 40% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of ingredient(s) chosen from aluminum silicates, plasticized vegetable or animal proteins, vitamin E, or mixtures thereof, • optionally from 1 to 30% by weight, preferably from 2 to 20% by weight, advantageously from 5 to 10% by weight, of PVOH or EVOH relative to the total weight of the formulation,

[0169] PI and P2 being advantageously obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0170] According to one embodiment, the formulation comprises: • from 50 to 98.9% by weight, preferably from 75 to 97.5% by weight, advantageously preferably from 80 to 94% by weight of polymer(s) chosen from PHBV and P3HB4HB, the PHBV polymer being a rather crystalline polymer and the P3HB4BH polymer being a rather amorphous polymer, • from 0.1 to 40% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, of aluminum silicates, • optionally from 1 to 30% by weight, preferably from 2 to 20% by weight, advantageously from 5 to 10% by weight, of PVOH or EVOH,

[0171] relative to the total weight of the formulation,

[0172] PI and P2 being advantageously obtained by aerobic and / or anaerobic fermentation engineering of biosourced material.

[0173] When the formulation comprises a mineral or organic filler chosen from silica, silicates, vitamin E or a plasticized animal or vegetable protein, the formulation may optionally also comprise one or more additives chosen from mineral fillers other than silicates, peroxide-type products, vitamins other than vitamin E, vegetable or animal waxes. According to this embodiment, said additive(s) may represent from 0.05 to 20% by weight, preferably from 0.1 to 15% by weight, advantageously from 1 to 10% by weight, of the total weight of the formulation.

[0174] Preferably, the formulation consists entirely of biodegradable and compostable materials (aerobic biological process) and / or methanizable materials (anaerobic biological process).

[0175] The formulation implemented in the invention is typically produced by extrusion, preferably by twin-screw extrusion. A formulation in the form of granules can then be obtained.

[0176] Typically, the capsule meets the EN 13432 standard in force since 2002.

[0177] Methanization is a technology based on degradation by micro-gold organisms of organic matter, in controlled conditions and in the absence of oxygen, therefore in an anaerobic environment, unlike composting which is an aerobic reaction.

[0178] Typically, when in use, the capsule containing at least one substance in powder or liquid form for preparing a beverage is inserted into a capsule holder of a beverage preparation machine, before closing the capsule holder and starting preparation of the beverage.

[0179] The capsule contains a substance in powder or liquid form for preparing a beverage. The beverage will preferably be coffee, tea, a chocolate product, preferably coffee. The substance in powder form for preparing coffee may be roasted and ground coffee, instant coffee or a mixture thereof.

[0180] The capsule according to the invention can be prepared according to the following process:

[0181] a) Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded;

[0182] b) injection molding the formulation into a mold to form a layer of at least the side wall and the circular rim of the enclosure, preferably the bottom, the side wall and the circular rim of the enclosure, optionally one or more other layers of the enclosure may be injection molded, typically using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation,

[0183] c) optionally filling the enclosure with the substance in powder or liquid form, if the base is not injection molded from the formulation, then the filling step is preceded by a step of placing a base of the monolayer or multilayer type in order to form an enclosure,

[0184] d) possibly closing the enclosure using the cover to form the capsule.

[0185] Alternatively, the capsule according to the invention can be prepared according to the following method:

[0186] a) preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded;

[0187] b) manufacturing plates or film by extrusion of the formulation before calendering or blowing, optionally manufacturing one or more other layers of at least the side wall and the circular rim of the enclosure by extrusion using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation,

[0188] c) shaping at least the side wall and the circular rim of the enclosure by thermoforming the plate onto or into a suitable shape

[0189] d) optionally filling the enclosure with the substance in powder or liquid form, if the base is not manufactured by thermoforming during step c), then the filling step is preceded by a step of placing a base of the monolayer or multilayer type in order to form an enclosure,

[0190] e) possibly closing the enclosure using the cover to form the capsule.

[0191] Preferably, the preparation method comprises a single injection molding or thermoforming step using the formulation defined in the invention. The enclosure according to the invention will then, according to this embodiment, consist of a single layer of formulation defined in the invention.

[0192] The enclosure generally has a thickness ranging from 0.2 to 1 mm, preferably from 0.3 to 0.8 mm. The bottom of the enclosure is capable of being perforated and may optionally include a recess.

[0193] The circular rim is formed during the production of the enclosure by thermoplastic injection in a mold having the appropriate shape. Said circular rim may have a width ranging from 1 to 4 mm. The main function of the circular rim is to abut against an edge of a capsule holder of the beverage-making appliance during the extraction phase of the beverage, for example coffee, and thus allow the capsule to be held firmly during the pressure build-up.

[0194] The mold for injection or the form for thermoforming will typically thus comprise a bottom or a support, a side wall and a circular rim, this in order to obtain each of the layers of the enclosure, preferably the enclosure will be made up of a single layer of the formulation of the invention.

[0195] According to a first embodiment, the side wall, the circular rim and the bottom are formed by injection molding or by thermoforming at least one formulation according to the invention and the lid is formed by a single-layer or multi-layer film. According to this first embodiment, the mold will comprise a bottom, a side wall and a circular rim.

[0196] According to a second embodiment, a support, the side wall and the circular rim are formed by injection molding or by thermoforming at least one formulation according to the invention and the lid and the bottom are formed by a single-layer or multi-layer film. According to this second embodiment, the mold will comprise a support (for example in the shape of a cross), a side wall and a circular rim.

[0197] The cover typically has a dimension calibrated so as to fit the contour of the circular rim of the capsule enclosure, thus closing the enclosure.

[0198] The substance in the form of powder, preferably ground coffee, or liquid is therefore trapped in the hollow enclosure. Typically, the lid will be glued or heat-sealed to the circular edge of the capsule enclosure.

[0199] According to one embodiment, the lid is made of a biodegradable and compostable film (aerobic biological process) and / or methanizable film (anaerobic biological process). Typically, the lid may be a single-layer or multi-layer film with a total thickness ranging from 90 to 300 μm.

[0200] The lid can thus be made up of one or more layers of materials chosen from paper, non-wovens, cellulose, barrier layers, these layers of materials being able to be separated by a layer of glue, which would itself be biodegradable and compostable (aerobic biological process) and / or methanizable (anaerobic biological process).

[0201] Among the nonwovens, mention may be made of polylactic acid (PLA) nonwovens or polyhydroxyalkanoate (PHA) or polybutylensuccinate (PBS) or polybutyl-lenadipat-terephthalate (PBAT) or polybutylene-co aliphate co terephthalate (PBAIT) nonwovens, the aliphatic diacid which can be, for example, sebacic acid.

[0202] Among the barrier layers, we can cite SiOx or A12O3 layers, PLA, hybrid organic polymer and inorganic fiber layers, layers coated with PVOH (polyvinyl alcohol) or EVOH (ethylene and vinyl alcohol copolymer), metallized layers for example using aluminum, barrier layers produced by vaporization (plasma deposition or by air vacuum).

[0203] By "barrier" is meant the ability of a material to limit or reduce the passage of oxygen and / or water vapor or humidity, we can then speak of a barrier layer to oxygen and / or humidity. Among the hybrid layers of organic polymer and inorganic compounds, we can cite layers comprising silicic acid polycondensates modified by organic groups and inorganic compounds. Among the organic groups, we can cite polycaprolactone, chitosan, celluloses. The silicic acid polycondensate contains Si-O-Si bonds. Among the inorganic compounds, we can cite silicon cations possibly in combination with other cations such as aluminum, titanium, boron or zirconium.

[0204] As examples of the production of the cover, we can cite:

[0205] - a cover made up of:

[0206] i) a film based on greaseproof paper or filter paper

[0207] ii) a layer of glue and / or a barrier layer,

[0208] iii) a layer of non-woven fabric,

[0209] once implemented in the capsule, layer i) is the outer layer and layer iii) is the layer inside the capsule;

[0210] - a cover made up of:

[0211] i) a filter paper-based film,

[0212] ii) a barrier layer,

[0213] iii) a barrier film such as a cellulose film or PLA film or PHA film,

[0214] iv) a layer of non-woven fabric,

[0215] once implemented in the capsule, layer i) is the outer layer and layer iv) is the layer inside the capsule;

[0216] - a cover made up of:

[0217] i) a cellulose or cellulose acetate film, for example of the Naturflex® type,

[0218] ii) a layer of non-woven fabric,

[0219] once implemented in the capsule, layer i) is the outer layer and layer ii) is the layer inside the capsule;

[0220] - a cover made up of:

[0221] i) a film of paper or filter paper,

[0222] ii) a hybrid barrier layer of organic polymer and inorganic compounds,

[0223] iii) a SiOx or A12O3 barrier layer,

[0224] iv) a cellulose barrier film,

[0225] v) a layer of non-woven fabric,

[0226] once implemented in the capsule, layer i) is the outer layer and layer v) is the layer inside the capsule.

[0227] - a cover made up of:

[0228] i) a biopolymer-based film such as PHA or PB AT or PBS or polybutylene-co aliphate co terephthalate (PBAIT), the aliphatic diacid being able to be, for example, sebacic acid or PLA,

[0229] ii) a barrier layer,

[0230] iii) a biopolymer-based film such as PHA or PB AT or PBS or PB AIT or even PLA,

[0231] once implemented in the capsule, layer i) is the outer layer and layer iii) is the layer inside the capsule

[0232] - a cover made up of:

[0233] i) a barrier layer,

[0234] ii) a biopolymer-based film such as PHA or PB AT or PBS or polybutylene-co aliphate co terephthalate (PBAIT), the aliphatic diacid possibly being, for example, sebacic acid or PLA,

[0235] once implemented in the capsule, layer i) is the outer layer and layer ii) is the layer inside the capsule.

[0236] Referring to [Fig.l], an enclosure 2 according to the invention consists of a base 3 of substantially circular shape and a side wall 4 provided with a circular rim 5.

[0237] Referring to [Fig.2], a capsule 1 according to the invention comprises an enclosure and a cover 6. The enclosure consists of a base 3 of substantially circular shape and a side wall 4 provided with a circular rim 5. The capsule according to the invention further comprises a substance in powder or liquid form for preparing a drink (introduced before closing the capsule using the cover) which has not been shown in [Fig.2].

[0238] The invention also relates to a method of manufacturing a capsule according to the invention.

[0239] According to a first embodiment, the method of the invention comprises the steps a. Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded; b. injection molding the formulation into a mold to form a layer of at least the sidewall and circular rim of the enclosure, optionally actually manufacturing one or more other layers of at least the side wall and the circular rim of the enclosure by extrusion using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation, c. possibly, filling the enclosure with the substance in powder form, d. possibly, closing the enclosure using the seal to form the capsule.

[0240] When the bottom is not a single-layer or multi-layer film, step b) of the manufacturing process preferably comprises a step of injection molding the formulation into a mold to form a layer of the enclosure comprising a bottom, a side wall and a circular rim.

[0241] When the base is a single-layer or multi-layer film, step b) of the manufacturing process preferably comprises a step of injection molding the formulation into a mold to form a layer of the enclosure comprising a support (for example a cross structure), a side wall and a circular rim.

[0242] Alternatively, the method of the invention comprises the steps: a. preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded, b. manufacturing plates or films by extrusion of the formulation before calendering or blowing, possibly manufacturing one or more other layers of the enclosure by extrusion using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation, c. shaping the enclosure by thermoforming the plate onto or into a suitable shape, d. possibly, filling the enclosure with the substance in powder or liquid form, e. possibly, closing the enclosure using the seal to form the capsule.

[0243] Preferably, the preparation method comprises a single injection molding or thermoforming step using the formulation defined in the invention. The enclosure according to the invention will then, according to this embodiment, consist of a single layer of formulation defined in the invention.

[0244] Finally, the invention relates to the use of a formulation as defined in the present invention in order to prepare a capsule having low permeability to gases and humidity.

[0245] Typically, the enclosure according to the invention has an oxygen permeability in less than 3.5 x 103 cm3 / capsule / 24hrs at 0.21atm at 23°C and 50%RH (relative humidity), preferably equal to or less than 3.0 x 103 cm3 / capsule / 24hrs at 0.21atm at 23°C and 50%RH, more preferably equal to or less than 2.90 x 103 cm3 / capsule / 24hrs at 0.21atm at 23°C and 50%RH, measured according to ASTM F1307 or ISO 15105-2. In the permeability measurement test, the enclosure is fixed on a plate, so that the plate helps to "close" the enclosure.

[0246] Advantageously, the capsule according to the invention has one or more of the following characteristics:

[0247] - a maximum stress of at least 35 MPa, preferably ranging from 35 to 65 MPa, more preferably from 39 to 60 MPa; and / or

[0248] - a Young's modulus of at least 900 MPa, preferably ranging from 1000 to 2400 MPa, more preferably from 1050 to 2100 MPa; and / or

[0249] - an elongation at maximum stress less than or equal to 8%, preferably ranging from 2 to 8%, more preferably from 2.5 to 7%; and / or

[0250] - a breaking stress of 25 to 80 MPa, preferably 35 to 70 MPa, more preferably preferably from 40 to 65 MPa; and / or

[0251] - an elongation at break of 1 to 15%, preferably of 2 to 10%, more preferably initially from 2.5 to 8%; and / or

[0252] - an impact resilience ranging from 2 to 20 kJ / m2, preferably from 3 to 15 kJ / m2, more preferably 4 to 10 kJ / m2.

[0253] These characteristics can be measured in accordance with the methods described in the experimental part.

[0254] For example, the maximum stress, Young's modulus, elongation at maximum stress, stress at break and elongation at break are measured in bending according to standard NF EN ISO 178 at a speed of 10 mm / min and advantageously at a temperature between 20 and 23°C and a relative humidity level between 45 and 55%.

[0255] Impact resilience can be measured according to standard NF ISO 179 (Charpy impact resistance) advantageously at a temperature between 20 and 23°C and a relative humidity level between 45 and 55%. Examples

[0256] The examples below illustrate work, which is not exhaustive, undertaken by the Applicant.

[0257] Example 1: Determination of the crystallinity rates of polymers PI and P2

[0258] Different polymers of the PHA family were sourced from several producers. DSC analyses were carried out on TA instruments DSC 2920 equipment (heating rate: + / - 10°C / min; sample mass of approximately 20 mg.

[0259] Table 1 below presents the results of the thermal analyses, in particular the melting temperatures (Tm), crystallization temperatures (Tc_n), cold crystallization temperatures (Tcc), enthalpy of fusion (AHml), and the crystallinity rate (Kc) of these polymers (with a literature enthalpy of fusion for the completely crystalline PHA AH°100%m> PHA = 146.6 J / g).

[0260] [Tables 1] Tc_n (°C) Tm (°C) AHml (J / g) Tcc (°C) Kc(%) PHBV 10 123 174 83.0 - 57% PHBH 12 62.1 160 23.5 - 16% PHBH 13 65 144 36.8 - 25% PHBH 15 44 107; 125; 163 14.3 57 10% P3HB4HB 00 49 85 0.29 / 0.2%

[0261] These characterizations make it possible to classify polymers according to their degree of crystallinity and thus they make it possible to classify polymers according to the nomenclature PI (rather crystalline) or P2 (weakly crystalline or even amorphous).

[0262] Example 2: formulations based on PL P2 polymers and other additives - Impact on mechanical properties

[0263] The Applicant has produced several formulations by extrusion, listed in Table 2 below in which the % are % by weight:

[0264] [Tables2] Formulation composition F89 80% PHBV 10 + 20% Kaolin F90 72% PHBV 10 + 25% Kaolin + 3% Triethyl citrate F91 90% PHBV 10 + 5% P3HB4HB 00 + 5% Kaolin F92 85% PHBV 10 + 5% P3HB4HB 00 + 10% Kaolin F93 80% PHBV 10 + 20% F89 F94 90% (80% PHBV 10 + 20% F89) + 10% P3HB4HB 00

[0265] Formulations F89, F90 and F93 are comparative formulations while formulations F91, F92 and F94 are according to the invention.

[0266] Impact and bending specimens (dimensions: L = 78 mm; 1 = 10 mm and Ep = 4 mm) were produced on a DK 25T press from these formulations. In addition, some PI and P2 polymers were injected.

[0267] Table 3 below shows the mechanical properties in bending according to standard NF EN ISO 178, measured on an Adamel Lhomargy Dynamometer with a 500 N force sensor, at a deformation rate of 10 mm / min.

[0268] The measurements are carried out at a temperature between 20 and 23°C and a relative humidity level between 45 and 55%.

[0269] “Max. stress” (MPa) means the maximum stress.

[0270] “Elongation at max. cont.” means the elongation at maximum stress.

[0271] “Break stress” means the stress at break.

[0272] The samples tested are the polymers of Table 1 and the formulations of Table 2.

[0273] [Tables3] Sample Number of tests Max. cont. (MPa) Young's modulus (MPa) Elongation at max. cont. (%) Cont. at break (MPa) Elongation at break (%) PHBH 12 5 12 + 0.65 204 + 37 9.23 + 0.57 / / PHBH 13 4 36 + 1.95 529 + 43 10.18 + 0.26 / / PHBH 15 3 24 + 0.47 280 + 6 10.68 + 0.15 / / PHBV 10 4 48 + 3.54 1015 + 110.00 4.89 + 0.67 46 + 3.39 5.01 + 0.71 F89 5 52 + 6.01 1798 + 133 2.62 + 0.34 51 + 5.94 2.63 + 0.35 F90 5 44 + 4.69 1737 + 275 2.50 + 0.30 43 + 4.51 2.53 + 0.31 F91 5 55 + 3.80 1408 + 157 4.37 + 0.55 53 + 3.63 4.56 + 0.64 F92 5 55 + 1.71 1378 + 176 4.84 + 0.41 53 + 2.49 5.06 + 0.57 F93 5 53 + 5.75 1728 + 173 3.51 + 0.66 52 + 5.55 3.57 + 0.69 F94 5 49 + 1.46 1142 + 81 6.06 + 0.88 47 + 1.72 6.40+1.11

[0274] The formulations according to the invention have a Young's modulus of the order of 1000 to 1410 MPa. This shows that the formulation according to the invention is not very rigid compared to comparative formulations or even to polymers, which gives them a flexibility sought after in the field.

[0275] As for the elongation at break which defines the capacity of a material to elongate before breaking when it is subjected to tensile or flexural stress, the results obtained with the formulations according to the invention, of the order of 5 to 7%, show a better capacity of the mixtures to deform before breaking.

[0276] Table 4 below gives the results of impact resilience (Acu) measured according to the NF ISO 179 standard (Charpy impact resistance). The measurements are carried out at a temperature between 20 and 23°C and a relative humidity level between 45 and 55%.

[0277] [Tables4] Resilience AcU [kj / m2] PHBH 12 27.4 + / - 2.7 PHBH 13 35.5 + / - 2.8 PHBH 15 46.7 + / - 1.7 PHBV 10 4.2 + / -1.1 F89 3.4 + / - 0.6 F90 5.8 + / - 2.1 F91 7.8 + / - 0.9 F92 7.6 + / - 1.0 F93 4.4+ / - 1.3 F94 8.7 + / - 0.7

[0278] With respect to the polymers, PHBH 12 and PHBV 15 showed no impact failure while complete failure occurred for PHBH 13 and PHBV 10.

[0279] In addition, the formulations according to the invention show a certain flexibility compared to the formulations not comprising polymer P2. Indeed, the examples in Table 4 illustrate the interest of the invention: the results obtained for the comparative formulations F89, F90 and F93, not comprising any polymer P2 (rather weakly crystalline or even rather amorphous) show that these formulations are too fragile, whereas the formulations F91, F92 and F94, according to the invention, make it possible to obtain better properties. Indeed, the incorporation of polymers P2 makes it possible to bring flexibility and resilience to the final composition, generating good func- functionality of use of the capsules.

[0280] Tables 3 and 4 show that the capsules according to the invention have better resilience and better elongation at break than the formulations which are not according to the invention, resilience and elongation at break being important factors influencing the fragility of the capsule during the manufacturing chain or during its use.

[0281] The Applicant also measured the thermal properties of the formulations. Table 5 below shows the crystallinity rates of formulations F90 to F94, according to the same methods as for polymers PI and P2 (of example 1).

[0282] [Tables5] Tc_n (°C) Tm (°C) AHml (J / g) Kcl (%) F90 120 171 83.3 79% F91 124 174 87.7 67% F92 125 174 85.3 69% F93 127 174 107.5 77% F94 124 174 79.5 63%

[0283] The results obtained according to Table 5 show that the incorporation of P2 polymers makes it possible to improve the mechanical properties, in particular the impact resistance.

[0284] Example 3: impact on rheological properties and thermal stability

[0285] Plastics processing methods for the implementation and shaping of polymers produce high shear rates, around 104 sec 1 for extrusion and injection, which induces reductions in molecular mass by chain cutting, and therefore losses in performance. The same is true for thermal stress which causes chain cutting by thermo-oxidation.

[0286] The Applicant has carried out thermal stability studies on certain polymers and certain formulations to measure the impact of adding P2 polymers to PL type polymers.

[0287] The characterizations were carried out using a plastometer: temperature of 183°C; load of 2.16 kg; all materials oven-cured at 80°C for 2 hours.

[0288] [Fig.3] shows the flows of the formulations (MFR) as a function of time in the plastometer.

[0289] As shown in [Fig.3], and surprisingly and unexpectedly, P2 polymers thermally stabilize PI polymers, as well as formulations based on them.

[0290] The implementation of the formulations according to the invention is therefore greatly facilitated.

[0291] Example 4: study of the impact on oxygen permeability

[0292] The oxygen permeability of capsules obtained from different polymers and different formulations was measured according to ASTM F1307 or ISO 15105-2.

[0293] Table 6 shows the results obtained from oxygen permeability.

[0294] [Tableauxô] [cm3 / capsule / 24hrs at 0.21atm] at 23°C and 50%RH PHBH 13 6.6* 103 PHBV 10 2.4* 103 F89 1.3* 103 F90 3.1*103 F91 2.35* 103 F92 2.25* 10-3 F93 1.9*103 F94 2.85*103

[0295] The incorporation of P2 polymers does not significantly deteriorate the permeability of the material to oxygen while, as already mentioned, considerably improving the mechanical and thermal properties of the capsules.

[0296] The best oxygen permeability is obtained with the comparative formulations F93 and F89 but with low values ​​of resilience and elongation at break and a high crystallinity which has the effect of weakening the capsule which can make it brittle during its transport, during its passage on the filling lines or during its use in the machines for the extraction of the beverage.

[0297] Formulations F91, F92 and F94 according to the invention have a plasticizing effect compared to a comparative formulation in which a mineral filler has been added in order to increase the oxygen permeability, without however significantly penalizing the oxygen permeability in the final formulation.

[0298] In conclusion, the subject of the invention has a fourfold interest: the controlled combination according to the invention of PI polymers with a degree of crystallinity greater than or equal to 50%, and the addition of P2 polymers with a degree of crystallinity less than or equal to 30% and more particularly less than or equal to 5%, with or without additives (in inorganic fillers, plasticizers, etc.) makes it possible to: - meet the mechanical property requirements for use of capsules in a machine for extracting a beverage, P2 polymers providing a resilience and flexibility; - meet the mechanical property requirements during transport and passage through capsule filling lines, with P2 polymers providing resilience and flexibility; - guarantee a very good level of permeability to gases, particularly to oxygen: P2 polymers make it possible to obtain high levels of crystallinity, with or without nucleating agents, the weakly crystalline or even rather amorphous character of P2 polymers, even in low concentration, - improves the thermal stability of formulations when they are used in plastics processes, at high shear rates and high temperature levels

[0299] Thus, the presence of at least one amorphous polymer with a degree of crystallinity less than or equal to 5% in the formulation of the capsule makes it possible to obtain a capsule which meets the requirements of permeability to oxygen and which does not break while remaining biodegradable, in particular under the conditions of industrial composting and domestic composting (aerobic biological process) or even by methanization (anaerobic biological process) and this even when the enclosure is made up of a single layer of formulation

[0300] In conclusion, the capsules obtained according to the invention, i.e. obtained from a formulation comprising a weakly crystalline or even rather amorphous polymer and a rather crystalline polymer are not brittle and always have good rigidity as well as sufficient impact resistance and elongation at break to be compatible with Nespresso® type machines. The addition of a plasticizer (such as Citrofol) does not make it possible to obtain such good mechanical strength and oxygen barrier properties.

[0301] Thus, the presence of at least one weakly crystalline copolymer from the PHA family or even rather amorphous in the formulation of the capsule makes it possible to obtain a capsule which meets the requirements of permeability to oxygen and which does not break while remaining biodegradable, in particular under industrial composting and domestic composting conditions and even when the enclosure is made up of a single layer of formulation.

Claims

Claims

1. Capsule (1) for preparing a beverage, said capsule comprising an enclosure (2) comprising at least one side wall (4) having a circular rim (5), characterized in that the side wall and the circular rim are formed by injection molding or by thermoforming at least one formulation comprising: (i) at least one polymer PI chosen from polyhydroxyalkanoates (PHA); and (ii) at least one polymer P2 chosen from polyhydroxyalkanoate (PHA), said polymer PI having a degree of crystallinity (Kcl) greater than or equal to 50%, and said polymer P2 having a degree of crystallinity (Kc2) less than or equal to 30%, preferably less than or equal to 5%.

2. Capsule according to claim 1, characterized in that said polyhydroxyalkanoates are chosen from polyhydroxybutyrate (PHB) polymers, preferably polymer PI and / or polymer P2 are PHB copolymers.

3. Capsule according to one of claims 1 or 2, characterized in that the polymer P1 contains monomeric units Mla of hydroxybutyrates 3HB and monomeric units Mlb chosen from hydroxyvalerate HV, 3-hydroxyhexanoate HH or 4hydroxy-butyrate 4HB, Mla being different from Mlb, and / or the polymer P2 contains monomeric units M2a of hydroxybutyrates 3HB and monomeric units M2b chosen from hydroxyvalerate HV, 3-hydroxyhexanoate HH or 4hydroxy-butyrate 4HB, M2a being different from M2b, preferably the mass ratio Mlb / Mla is less than or equal to 0.07, preferably less than or equal to 0.6 and / or the mass ratio M2b / M2a is greater than or equal to 0.05, preferably ranges from 0.1 to 1, more preferably 0.2 to 0.

9.

4. Capsule according to one of claims 1 to 3, characterized in that the polymer PI and / or the polymer P2 are obtained by aerobic and / or anaerobic fermentation engineering in a bio-sourced manner.

5. Capsule according to any one of claims 1 to 4, characterized in that the polymer(s) PI represent from 70 to 99% by weight, preferably from 80 to 98% by weight, of the total weight of the polymers PI and P2 and / or the polymer(s) P2 represent from 1 to 30% by weight, of preferably from 2 to 20% by weight, more preferably from 3 to 10% by weight, of the total weight of the polymers PI and P2.

6. Capsule according to any one of claims 1 to 5, in which the formulation comprises from 50 to 99.9% by weight, preferably from 75 to 99.5% by weight, advantageously from 90 to 99% by weight, of polymer(s) PI and P2, relative to the total weight of the formulation.

7. Capsule according to any one of claims 1 to 6, characterized in that the formulation further comprises at least one mineral or organic filler, preferably in a proportion ranging from 0.1 to 50% by weight, preferably from 0.5 to 25% by weight, advantageously from 1 to 15% by weight, preferably said filler is chosen from silica, silicates, double laminar hydroxides (HDL), titanium oxide, vitamin E, plasticized animal or vegetable proteins, or mixtures thereof, relative to the total weight of the formulation.

8. Capsule according to the preceding claim, in which the BET specific surface area of ​​the silicates is between 1 and 250m2 / g and / or the median diameter of the silicates is between 0.5 and 20qm and / or the dimensional form factor of the silicates is greater than or equal to 1:

2.

9. Capsule according to any one of claims 1 to 8, wherein the formulation further comprises at least one polyvinyl or ethylene vinyl alcohol, preferably in an amount ranging from 1 to 30% by weight, preferably from 2 to 20% by weight, advantageously from 5 to 10% by weight, relative to the total weight of the formulation.

10. Capsule according to any one of claims 1 to 9, said capsule - being biodegradable and / or compostable in industrial or domestic conditions or by methanization and / or - containing at least 80% by weight of biosourced carbon, relative to the total weight of carbon atoms in the capsule.

11. A capsule according to any one of claims 1 to 10, wherein the enclosure comprises a bottom and wherein the bottom, side wall and circular rim are formed by injection molding or thermoforming, preferably in a single layer of said formulation in a mold.

12. Capsule according to any one of claims 1 to 11, containing a substance in powder or liquid form, said capsule comprising a seal (6) welded around the edge of the rim of the enclosure, preferably the lid, comprises a single-layer or multi-layer film, said film comprising one or more materials chosen from materials which are biodegradable and compostable according to an aerobic biological process and / or methanizable according to an anaerobic biological process, preferably the material is chosen from paper, non-wovens, cellulose, SiOx layers, polymers based on poly-lactic acid, polyhydroxyalkanoates, hybrid layers of organic polymer and inorganic fibers, layers coated with poly-vinyl alcohol or copolymer of ethylene and vinyl alcohol, metallized layers preferably using aluminum, these layers of materials being optionally separated by a layer of glue.

13. Capsule according to claim 12, in which the lid is made of a multilayer film comprising: i) a paper film or filter paper, ii) a barrier layer, preferably the barrier layer comprising one or more layers chosen from: - a hybrid barrier layer comprising an organic polymer and inorganic compounds, and / or - a SiOx barrier layer, and / or - a cellulose barrier layer, iii) a layer of non-woven fabric, said layer of non-woven fabric being inside the capsule.

14. Capsule according to claim 12, in which the seal is made of a multilayer film comprising: i) a barrier layer, ii) a film based on biopolymers such as polyhydroxyalkanoates PHA or polybutylenadipate-terephthalate PB AT or polybutylen-succinate PBS or polybutylene-co aliphate co-terephthalate PBA1T or polylactic acids PLA, Or a multilayer film comprising: i) a biopolymer-based film such as polyhydroxyalkanoates PHA or polybutylenadipate-terephthalate PB AT or polybutylen-succinate PBS or polybutylene-co aliphate co-terephthalate PBA1T or polylactic acidsPLA, ii) a barrier layer, iii) a biopolymer-based film such as polyhydroxyalkanoates PHA or polybutylene co-adipate co-terephthalate PB AT or poly-butylene succinate PBS or polybutylene co-aliphate-co terephthalate PB AIT or even polylactic acids PLA.

15. A method of manufacturing a capsule according to any one of claims 1 to 14, comprising the following steps: a. Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded, b. injection molding the formulation obtained in step a) into a mold to form a layer of at least the side wall (4) and the circular rim (5) of the enclosure (2), optionally one or more layers of the enclosure (2) may be injection molded, using a formulation different from the formulation of step a), c. filling the enclosure (2) with the substance in powder or liquid form, if the base is not injection molded from the formulation, then the filling step is preceded by a step of placing a single-layer or multi-layer type base in order to form the enclosure, d. possibly, closing the enclosure (2) using the cover to form the capsule, Or including the following steps: a. Preparation of the formulation by mixing the ingredients, said ingredients possibly being extruded, b. Manufacture of plates or a film by extrusion of the formulation before calendering or blowing, optionally manufacture of one or more other layers of at least the side wall (4) and the circular rim (5) of the enclosure by extrusion using at least one formulation different from the formulation of step a), for example using a PVOH or EVOH formulation, c. Shaping by thermoforming the plate or film into a suitable shape, d. filling the enclosure (2) with the substance in powder or liquid form, if the base is not shaped by thermoforming during step c), then the filling step is preceded by a step of placing a single-layer or multi-layer type base in order to form the enclosure, e. possibly, closing the enclosure (2) using the operculum to form the capsule.

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