food container lid comprising a hydrophilic film

Abstract

Lid (1) for a food container comprising a plastic body (11) and a seal (12) assembled to the inner wall (11b) of the body (11), characterized in that the inner wall (11b) of the body is at least partly covered with a hydrophilic film (3) and in that the exterior of the seal (12) is at least partly covered with a hydrophilic film (3). Figure for the abstract: figure 2.

Description

Title of the invention: Food container cover comprising a hydrophilic film FIELD OF THE INVENTION

[0001] The invention relates to the field of lids for food containers, in particular lids for containers intended for the transport of food products. STATE OF THE ART

[0002] In the food container industry, sealing is a major concern, particularly for containers intended for the transport of food.

[0003] Conventionally, the sealing of food containers is ensured by the compression of a seal present on the lid, compression caused by the user during locking. This requires the user to exert a certain amount of effort when locking and then unlocking the lid.

[0004] Known seals are generally made of plastic materials or silicone elastomers. These materials, when used in food container seals, have a temperature of use higher than their glass transition temperature. This allows the seals to be sufficiently deformable to fit the geometry of the lid. However, it is known that above the glass transition temperature, these materials have a large free volume which promotes diffusion phenomena which are detrimental to the sealing of the food container beyond a storage period of 24 hours. To maintain the seal, the locking force to be provided by the user must therefore be high.

[0005] If the effort required by the user to compress the seal is too high, locking and unlocking the lid will be difficult. Reducing the effort required by the user is therefore a constant design concern to facilitate the use of food containers.

[0006] However, reducing the force to be applied by the user generally has the effect of reducing the compression of the lid seal, and therefore making the food container less airtight.

[0007] Known food container lids are generally made of plastic materials, which naturally have a low surface tension. This low surface tension promotes the phenomenon of dewetting, i.e. the process by which the contact area becomes solid and a wetting film spontaneously reduces.

[0008] It is known that the dewetting phenomenon can be advantageous for ensuring good sealing of food containers, because the contact between the closure zone of the container and food liquids is made more punctual (food liquids form drops on the surface of the lid). In addition, the use of plastic materials allows the manufacture of lids of complex geometric shapes by known injection techniques.

[0009] However, the formation of drops induced by the low surface tension of plastic materials makes drying more difficult, the liquid contained in the drops being more difficult to evaporate. These drying difficulties promote the appearance of mold during the aging of food containers.

[0010] Furthermore, the dewetting phenomenon in the compression zone can lead to the formation of drops on the seal, which can have the effect of increasing the contact time between the liquid and the seal and promoting liquid leaks if the compression of the cover seal is not sufficient.

[0011] Thus, there is a need to develop improved food container lids, making it possible to ensure good sealing while overcoming the drawbacks described. Statement of the invention

[0012] The applicant has developed a lid having advantageous properties. It has demonstrated, surprisingly, that the presence of a hydrophilic film on at least part of the exterior of the seal and on at least part of the interior wall of the lid makes it possible to ensure good sealing of the food container and to limit the effort required by the user when locking or unlocking the lid.

[0013] The described invention also has one of the following advantages: - provide good sealing against water and / or oil, particularly during transport of the food container; - facilitate the opening and / or closing of the food container, which is particularly advantageous for children, the elderly or for the user with one hand occupied; - limit the formation of drops on the cover which allows better drying after washing (for example after washing in the dishwasher); - reduce the risks of diffusion associated with excessively prolonged contact between water and / or oil and the seal whose glass transition temperature is lower than its operating temperature; - reduce the risk of mold appearing during the aging of the food container; - allow the manufacture of a watertight cover in a limited number of steps, the seal being able to be assembled to the cover (in particular by overmolding or by co-injection) before the hydrophilic film is formed on the surface of the lid. Summary of the invention

[0014] According to a first aspect, there is provided a food container lid comprising a plastic body and a seal assembled to the inner wall of the body, characterized in that the inner wall of the body is at least partly covered with a hydrophilic film and in that the exterior of the seal is at least partly covered with a hydrophilic film.

[0015] According to advantageous and non-limiting characteristics, taken alone or in any combination: - the hydrophilic film is a coating comprising one or more element(s) chosen from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminum oxides, amorphous carbon, and mixtures thereof; - the inner wall of the body and the exterior of the seal have been subjected to a plasma treatment of one or more non-polymerizable gases to form the hydrophilic film; - the body comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), translucent or non-transparent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), copolyesters (including TritanTM synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or a mixture thereof; - the outer wall of the body is covered with a hydrophilic film; - the seal comprises one or more thermoplastic elastomer(s); - the seal is overmolded onto the body or the seal has been co-injected with the body.

[0016] According to a second aspect, there is provided a food container comprising a lid as presented previously and a container.

[0017] According to advantageous and non-limiting characteristics, taken alone or in any combination: - the inner wall(s) of the container are covered with a hydrophilic film; - the outer wall(s) of the container are covered with a hydrophilic film.

[0018] According to a third aspect, the use of a hydrophilic film is also proposed for covering at least part of the exterior of a seal and at least part of the inner wall of the plastic body of a food container lid, to increase the tightness of the food container and / or reduce the compressive force to be applied by the user when locking and / or unlocking the lid.

[0019] According to a fourth aspect, a method of manufacturing a cover as presented previously is proposed, comprising the following successive steps: a) providing a plastic body having a seal assembled to the inner wall of the body, b) simultaneously covering at least a portion of the inner wall of the body and at least a portion of the exterior of the seal with a hydrophilic film.

[0020] According to advantageous and non-limiting characteristics: - the method comprises a step a.0) of manufacturing the body by injection or co-injection;

[0021] - the method comprises a step al) of overmolding the seal on the inner wall of the body or manufacture of the seal by co-injection with the body;

[0022] - in step b), a coating comprising one or more element(s) chosen from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminum oxides, amorphous carbon, and mixtures thereof, is applied to the inner wall of the body and to the seal by plasma-enhanced chemical vapor deposition (PECVD);

[0023] - a precursor of the siloxane or disiloxane type, preferably hexamethyldisiloxane (HDMSO), is used for plasma-enhanced chemical vapor deposition PECVD;

[0024] - step b) comprises a step of simultaneous surface treatment of at least one part of the inner wall of the body and at least part of the exterior of the seal by plasma of one or more non-polymerizable gas(es).

[0025] Other aspects of the invention are as described below and in the claims. Description of figures

[0026] Other characteristics and advantages of the present invention will appear on reading the following description of a preferred embodiment. This description will be given with reference to the appended figures, including: - [Fig.l] illustrates a food container comprising a lid and a container - [Fig.2] illustrates a lid of a food container; - [Fig.3] is a sectional view of a food container; - [Fig.4] represents the steps of a manufacturing process for a food container lid. Definitions

[0027] For the purposes of the present invention, the term "food container" means any container capable of coming, at least partially, into contact with solid or liquid foodstuffs, and intended for storing, transporting, preparing and / or cooking foodstuffs. Advantageously, the food container according to the present invention is capable of transporting foodstuffs.

[0028] For the purposes of the present invention, the term "film" means a continuous layer, i.e., a single whole forming a flat surface covering the desired surface. A film may be single-layer or multi-layer. The term "film" includes, in particular, for the purposes of the present invention, any layer formed by the modification of the surface of the material in question, for example after a physical, chemical or physicochemical surface treatment, as well as any layer deposited on the surface of the material in question (called a coating). The thickness of the film may vary, for example along the surface that it covers. This will be the case in particular when the film is formed by a surface treatment.

[0029] For the purposes of the present invention, the term “hydrophilic film” means a film having a surface tension greater than the surface tension of the material to which it is affixed.

[0030] By "seal" is meant a gasket which ensures the sealing of the assembly of fixed or moving parts. In the present case, the seal 12 aims to ensure the sealing of the assembly of a lid 1 and a container 2 of a food container 100 as illustrated in figures 2 and 3. In other words, the seal 12 is a material suitable for being placed at the junction between the lid 1 and the container 2 of a food container 100 to make the container leaktight when the lid 1 is assembled to the container 2. More characteristics of the seal 12, such as its constituent material(s) or its shape, will be detailed below. Detailed description of the invention Cover

[0031] In a first aspect, with reference to [Fig.l], there is provided a cover 1 for a food container 100 comprising a plastic body 11 and a seal 12 assembled on the inner wall of the body 11b, in which at least a portion of the inner wall 11b of the body 11 and at least a portion of the exterior of the seal 12 are covered with a hydrophilic film 3.

[0032] The lid 1 is capable of being coupled to a container 2 to form a food container 100. Advantageously, the lid 1 is capable of being reversibly coupled to the container 2. In other words, the lid 1 is suitable for being coupled / decoupled to the container 2 multiple times.

[0033] The plastic body 11 of the cover 1 according to the invention comprises an outer wall 11a and an inner wall 11b.

[0034] With reference to Figures 2 and 3, the inner wall 11b is adapted to be arranged facing the container 2 when the lid 1 is assembled to the container 2. The inner wall 11b comprises at least one main part 111b which is adapted to, when the lid 1 is assembled to the container 2, be facing the inner wall 2b of the container 2. In other words, the main part 111b can be in contact with food when the lid 1 is assembled to the container 2 and the container 2 contains food, in particular in a situation where the food container 100 is turned upside down and the food comes into contact with the main part 111b of the inner wall 11b of the body 11. It will be seen later that the main part 111b is advantageously delimited by the seal 12. The inner wall can further comprise one or more secondary parts 112b, for example adapted to be facing an outer wall 2a of the container 2. 2.

[0035] Advantageously, the food container 100 comprises means 4 for fixing, advantageously reversibly, the cover 1 to the container 2. In other words, the fixing means 4 make it possible to fix the cover 1 to the container, preferably even when the food container 100 is moved or changed orientation (for example turned over).

[0036] According to an embodiment illustrated in Figures 1 to 3, the fixing means 4 comprise one or more male parts 41 and one or more female parts 42, the male parts 41 being adapted to assemble with the female parts 42 so as to ensure the fixing of the cover 1 to the container 2. In the example of Figures 1 to 3, which is a “clip” type configuration, the male parts 41 take the form of fins 41 of the cover 1 and the female parts 42 take the form of a projecting part 42 of the container 2. The projecting part 42 projects from the container 2. In this case, the cover 1 comprises the male parts 41 and the container comprises the female part 42. Each fin 41 comprises a tab 411 projecting from the fin 4L. The tabs 411 of the fins 41 are adapted to engage against the projecting part 42 so as to fix the cover 1 to the container 2.

[0037] Other embodiments of fastening means 4 may be envisaged. Those skilled in the art know different types of fastening means 4 adapted to the food container 100. For example, the male part 41 and the female part 42 of the fastening means 4 may be threads. The lid 1 may comprise a thread and the container 2 may comprise a thread complementary to the thread of the lid 1 so that the lid 1 is thus adapted to be screwed to the container 2.

[0038] The plastic body 11 according to the invention comprises one or more plastic material(s). Advantageously, the body 11 is composed mainly of one or several plastic materials.

[0039] Advantageously, the body 11 comprises one or more polymer(s) chosen from the group consisting of polyethylene (PE) (in particular high density polyethylene (HDPE)), polypropylene (PP), polyethylene terephthalate (PET), glycolized polyethylene terephthalate (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), translucent or non-transparent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), copolyesters (in particular Tritan™ synthesized from terephthalate monomers) dimethyl, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, the body 11 of the cover 1 comprises more than 50% by weight of polyethylene (PE), polypropylene (PP) or a mixture of the two, even more advantageously more than 80%, even more advantageously more than 90%, even more advantageously more than 99%. Preferably, the body 11 comprises more than 99% by weight of polypropylene (PP).

[0040] The cover 1 according to the invention comprises at least one seal 12. Advantageously, the seal 12 takes the form of a thin strip. By thin thickness, it is understood that the seal 12 preferably has a thickness less than or equal to 15 mm, or even less than or equal to 10 mm. The strip, i.e. the seal 12, can have different shapes; for example, it can be rectilinear, elliptical, circular, rectangular, etc.

[0041] Advantageously, the shape of the seal 12 depends on the shape of the part of the container 2 which is adapted to be in contact with the seal 12 when the lid 1 is arranged on the container 2, in a closed configuration. In the example illustrated in [Fig. 3], the seal 12 is adapted to be in contact with the rim 2c of the container 2. The rim 2c of the container 2 corresponds to the upper edge of the container 2c. In other words, the rim 2c corresponds to the portion connecting the outer wall 2a of the container 2 to the inner wall 2b of the container 2. In the example illustrated in the various figures, the rim 2c has a rectangular shape and, consequently, the seal 12 has a rectangular shape, with dimensions substantially identical to those of the rim 2c. This makes it possible to ensure the sealing of the food container 100.Indeed, it is desired that the seal 12 runs along the entire junction between the lid 1 and the container 2 to prevent leaks when the food container 100 is closed. Therefore, advantageously, when the lid 1 is positioned on the container 2 in the closed configuration, the seal 12 seals the cavity 20 defined by the container 2 (i.e. the interior of the container) so that there is no fluid communication between the cavity 20 of the container 2 and . the external environment.

[0042] Advantageously, the seal 12 forms a continuum so as to delimit a closed zone of the inner wall 11b of the body 11. This closed zone is advantageously the main part 111b of the inner wall 11b of the body 11 which was presented previously.

[0043] Advantageously, the seal 12 comprises one or more polymer(s) chosen from the group consisting of rubbers, silicones, and thermoplastic elastomers (TPE). Advantageously, the seal 12 comprises more than 50% by weight of one or more thermoplastic elastomers (TPE), even more advantageously more than 80%, even more advantageously more than 90%, even more advantageously more than 99%.

[0044] The seal 12 according to the invention is assembled to the body 11, more precisely to the inner wall of the body 11 of the cover 1.

[0045] For example, the seal 12 can be assembled to the body 11 using known techniques, such as gluing, overmolding, or co-injection (multi-material injection) of the body 11 and the seal 12. The seal 12 can also be housed in the body 11, for example in a groove formed in the body 11 so that the seal 12 is inserted and fixed in said groove.

[0046] Advantageously, the seal 12 is assembled on the body 11 by overmolding or by means of a co-injection molding operation with the body 11, preferably by means of a co-injection molding operation.

[0047] At least a portion of the inner wall of the body 11b and at least a portion of the exterior of the seal 12 according to the invention are covered with a hydrophilic film 3.

[0048] At least a portion of the inner wall of the body 11b is covered with a hydrophilic film 3. The entire inner wall 11b of the body, i.e. the entirety of the inner wall 11b, may be covered with a hydrophilic film 3. Advantageously, the entirety of the inner wall 11b, with the exception of the portion in contact with the seal 12, is covered with a hydrophilic film. Indeed, when the body 11 and the seal 12 are assembled prior to the affixing of the hydrophilic film 3, the part of the inner wall 11b in contact with the seal will not be accessible since it is covered by the seal 12 and will therefore not be covered by the hydrophilic film 3. In a preferred embodiment, the entire part of the inner wall 11b which is accessible, that is to say the entire part which is not masked by the seal, is covered by a hydrophilic film 3.

[0049] The exterior of the seal 12 is a part of the seal 12 which is defined when the seal 12 is assembled to the body 11. By “exterior of the seal 12”, is meant the part of the seal 12 which is facing the external environment when the cover 1 is not assembled to a container 2. In other words, the exterior of the seal 12 is not a part of the seal 12 which is in contact with the body 11 of the lid 1. The exterior of the seal 12 is the part of the seal 12 which is directly visible. Directly visible is opposed to indirectly visible, that is to say visible only through the body 11 if the latter is transparent. The exterior of the seal 12 is a part of the seal 12 which is adapted to be at least partially in contact with the container 2 and possibly opposite the interior of the container 2 when the lid 1 is assembled to the container 2. In other words, the exterior of the seal 12 is a part of the seal 12 which is likely to be covered with a hydrophilic film 3 since this part of the seal 12 is accessible.

[0050] At least a portion of the exterior of the seal 12 is covered with a hydrophilic film 3. The entire exterior of the seal 12, i.e. the entire exterior of the seal 12, may be covered with a hydrophilic film 3.

[0051] Advantageously, the outer wall of the body 11 is also covered with a hydrophilic film 3. The hydrophilic film 3 covering the outer wall of the body 11 may be the same or different from the hydrophilic film 3 covering the inner wall of the body 11 and the exterior of the seal 12.

[0052] According to a particular embodiment, the hydrophilic film 3 consists of a coating deposited on the surface considered.

[0053] Among the coatings that can be used in the present invention, mention may in particular be made of metallic, mineral, ceramic coatings, and more particularly coatings based on aluminum, silicon and / or carbon.

[0054] The preferred coatings according to the invention are coatings comprising one or more elements chosen from: - silicon oxides, - silicon nitrides, - silicon oxynitrides, - aluminum oxides, - amorphous carbon, hydrogenated or not. Coatings comprising one or more silicon oxides are particularly preferred for being deposited on the inner wall of the body 11 and the exterior of the seal 12.

[0055] According to another embodiment, the hydrophilic film 3 consists of a layer formed following a modification of the molecular chains of the materials making up the surface in question.

[0056] This surface modification can in particular be induced by a physicochemical treatment of the plasma or corona or laser type, a chemical activation or a combination of these different techniques. Advantageously, the surface modification is induced by a plasma treatment. Even more advantageously, the modi Surface treatment is induced by plasma treatment using non-polymerizable gases such as argon, helium, oxygen, nitrogen or their mixtures such as air. Among these gases, plasma treatment using nitrogen is particularly preferred.

[0057] The chemical nature of the hydrophilic film 3 formed following a modification of the surface depends on the nature of the treatment applied and the nature of the materials making up the treated surface. For example, the use of a plasma treatment using nitrogen would be likely to result in the formation of a hydrophilic film 3 comprising nitrogen-containing hydrocarbon ions (CN, CxHyN) and oxygenated nitrogen-containing hydrocarbon ions (CNO, CxHyNzOw) on the surface of the plastic materials.

[0058] Advantageously, the thickness of the hydrophilic film 3 is less than 200 nm. Food container

[0059] With reference to Figures 1 and 3, a food container 100 is proposed comprising a lid 1 as presented previously and a container 2.

[0060] Advantageously, the food container 100 according to the invention is intended to transport food.

[0061] With reference to [Fig. 3], the container 2 defines a cavity in which food can be placed. The container 2, and therefore its cavity 20, can have any type of shape. For example, the container 2 can be parallelepipedal.

[0062] The container 2 comprises an outer wall 2a and an inner wall 2b. The inner wall 2b, as opposed to the outer wall 2a, is intended to be in contact with the food contained in the cavity 20.

[0063] The container 2 according to the invention may be mainly made of metal, glass or plastic materials.Advantageously, the container 2 comprises one or more polymer(s) chosen from the group consisting of polyethylene (PE) (in particular high density polyethylene (HDPE)), polypropylene (PP), polyethylene terephthalate (PET), glycolized polyethylene terephthalate (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), translucent or non-transparent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, the container 2 comprises more than 50% by weight of polyethylene (PE), polypropylene (PP) or a mixture of the two, even more advantageously more than 80%, even more advantageously more than 90%, even more advantageously more than 99%. Preferably, the container 2 comprises more than 99% by weight of polypropylene. (PP).

[0064] Advantageously, the inner wall(s) of the container 2 are covered with a hydrophilic film 3 according to the invention. It is envisaged in a variant that the container 2 is not covered with a hydrophilic film, in particular when the container 2 is made of metal or glass. The hydrophilic film 3 covering the inner wall(s) of the container 2 may be the same or different from the hydrophilic film 3 covering the inner wall of the body 11 and the seal 12 of the lid 1. Advantageously, this hydrophilic film will be the same as the hydrophilic film 3 covering the inner wall 11b and the seal 12 of the lid 1. Preferably, the hydrophilic film 3 covering the inner wall(s) of the container 2 is a coating comprising one or more silicon oxides.

[0065] Advantageously, the outer wall(s) of the container 2 are covered by a hydrophilic film 3 according to the invention. This hydrophilic film 3 may be the same or different from the hydrophilic film 3 covering the inner wall of the body 11 and the seal 12 of the lid 1, and where appropriate, from the film covering the outer wall(s) of the container 2. Advantageously, the hydrophilic film 3 covering the outer wall(s) of the container 2 is the same as the hydrophilic film 3 covering the outer wall 11a of the body 11 of the lid 1 where appropriate. Use

[0066] The invention also relates to the use of a hydrophilic film 3 according to the invention to cover at least a part of the exterior of the seal 12 and a part of the interior wall of the plastic body 11 of a cover 1 of a food container 100, in order to increase the sealing of the food container 100 and / or reduce the compression force to be applied by the user when locking and / or unlocking the cover 1.

[0067] Advantageously, a hydrophilic film 3 consisting of a coating comprising one or more silicon oxides is used.

[0068] The leaktightness of the food container 100 can be measured using the following technique: the container is filled with a liquid, the lid is placed on this container and locked, then the container is positioned vertically. In the vertical position, a leak can thus be detected. By "vertically", it is understood that the container is positioned on one of its side walls. In other words, the container is placed on a surface, preferably flat, so that one of the side walls of the container is in contact with the surface. In other words, when the container is positioned vertically, it is not placed in a conventional manner, that is to say, it is not the bottom of the container which is in contact with the surface on which the container is placed.

[0069] The compression force to be applied by the user when locking and / or unlocking the cover 1 can be measured by determining the percentage of com- joint pressure, which can advantageously range from 5 to 27%. Process

[0070] With reference to [Fig.4], a method of manufacturing a cover 1 according to the invention is proposed, comprising the following successive steps:

[0071] a) providing a plastic body 11 having a seal 12 assembled to the inner wall of the body 11,

[0072] b) simultaneously covering at least a portion of the inner wall of the body 11 and at least a portion of the exterior of the seal 12 with a hydrophilic film 3. Step a)

[0073] The plastic body 11 of step a) comprises one or more plastic material(s). Advantageously, the body 11 is composed mainly of one or more plastic materials.

[0074] Advantageously, the body 11 comprises one or more polymer(s) chosen from the group consisting of polyethylene (PE) (in particular high density polyethylene (HDPE)), polypropylene (PP), polyethylene terephthalate (PET), glycolized polyethylene terephthalate (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), translucent or non-transparent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), copolyesters (in particular Tritan™ synthesized from terephthalate monomers) dimethyl, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, the body 11 of the cover 1 comprises more than 50% by weight of polyethylene (PE), polypropylene (PP) or a mixture of the two, even more advantageously more than 80%, even more advantageously more than 90%, even more advantageously more than 99%. Preferably, the body 11 comprises more than 99% by weight of polypropylene (PP).

[0075] The plastic body 11 provided in step a) can advantageously be manufactured using injection molding, co-injection molding, injection-blow molding, blow molding, stamping and / or extrusion techniques. Injection molding or co-injection molding (multi-material injection) is particularly preferred. Thus, advantageously, the method comprises a step a.0) of manufacturing the plastic body 11 by injection or co-injection.

[0076] Advantageously, the seal 12 assembled to the plastic body 11 comprises one or more polymer(s) chosen from the group consisting of rubbers, silicones, and thermoplastic elastomers (TPE). Advantageously, the seal 12 comprises more than 50% by weight of one or more thermoplastic elastomers (TPE), even more advantageously more than 80%, even more advantageously more than 90%, even more advantageously more than 99%.

[0077] In a particular embodiment, the seal 12 is assembled to the body 11 after the manufacture of the body 11. As explained previously, this assembly can for example be carried out by gluing, overmolding or by housing the seal 12 in the body 11 of the cover 1. Advantageously, the seal 12 is assembled to the body 11 by overmolding.

[0078] In another embodiment, the seal 12 and the body 11 are manufactured and assembled within the same machine using co-injection molding techniques (multi-material injection). Multi-material injection is particularly advantageous because it makes it possible to obtain, in a limited time and in a single operation, a seal 12 securely assembled to the body 11.

[0079] Thus, in a particularly advantageous manner, the method comprises a step a. 1) of overmolding the seal 12 on the inner wall of the body 11 or of manufacturing the seal 12 by co-injection with the body 11. Steps a.0) and a. 1) can therefore be successive or simultaneous. Step b)

[0080] Step b) consists of covering at least part of the inner wall of the body 11 and at least part of the exterior of the seal 12 with a hydrophilic film 3 according to the invention.

[0081] Advantageously, the entire inner wall 11b is covered with a hydrophilic film 3 in step b), with the exception of the part of the inner wall 11b) which is in contact with the seal (and which is therefore not accessible because it is covered by the seal 12).

[0082] Advantageously, the entire exterior of the seal 12 is covered with a hydrophilic film 3.

[0083] Advantageously, at least one part of the inner wall of the body 11 and at least one part of the exterior of the seal 12 are covered simultaneously with the same hydrophilic film 3. It is also possible to cover the inner wall of the body 11 and at least one part of the exterior of the seal 12 with the same hydrophilic film 3 in a sequential manner, for example by first applying the hydrophilic film 3 to the seal 12, then to the inner wall of the body 11, or vice versa.

[0084] In a particular embodiment, step b) consists of subjecting the inner wall of the body 11 and the seal 12 to a surface treatment in order to form a hydrophilic film 3.

[0085] Advantageously, the surface treatment applied is a plasma treatment using non-polymerizable gases such as argon, helium, oxygen, nitrogen or their mixture in order to form a hydrophilic film 3 on the surface.

[0086] Among the surface treatments, plasma treatment using nitrogen is particularly particularly preferred. This treatment results in the presence of nitrogenous hydrocarbon ions (CN, CxHyN ) and oxygenated nitrogen ions (CNO, CxHyNzOw ).

[0087] In another embodiment, step b) consists of applying to the inner wall of the body 11 and to the seal 12 a hydrophilic coating according to the invention.

[0088] Advantageously, the applied coating comprises one or more element(s) chosen from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminum oxides, amorphous carbon, and mixtures thereof.

[0089] Possible coating techniques include in particular chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD) or physical vapor deposition (PVD). Advantageously, the coating is applied by plasma-enhanced chemical vapor deposition (PECVD).

[0090] For plasma-enhanced chemical vapor deposition (PECVD), precursors of the siloxane or disiloxane type are preferably used, optionally in combination with oxygen and / or nitrogen. Preferably, hexamethyldisiloxane (HDMSO) is used as a precursor, advantageously in combination with oxygen. In a variant of this embodiment, step b) further comprises an additional surface treatment step, preferably a plasma surface treatment using non-polymerizable gases such as argon, helium, oxygen, nitrogen or a mixture thereof. This additional surface treatment step may be carried out before the deposition of the coating (for example, to facilitate its adhesion), or after the deposition of the coating (for example, to enhance the hydrophilic nature of the coating).

Claims

Claims

1. Lid (1) of a food container (100) comprising a plastic body (11) and a seal (12) assembled to the inner wall (11b) of the body (11), characterized in that the inner wall (11b) of the body is at least partly covered with a hydrophilic film (3) and in that the exterior of the seal (12) is at least partly covered with a hydrophilic film (3).

2. The cover (1) of claim 1, wherein the hydrophilic film (3) is a coating comprising one or more elements selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminum oxides, amorphous carbon, and mixtures thereof.

3. A lid (1) according to claim 1, wherein the inner wall (11b) of the body (11) and the exterior of the seal (12) have been subjected to a plasma treatment of one or more non-polymerizable gases to form the hydrophilic film (3).

4. Lid (1) according to any one of claims 1 to 3, wherein the body (11) comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), translucent or non-transparent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), polymethyl methacrylate (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or a mixture thereof.

5. Lid (1) according to any one of claims 1 to 4, wherein the outer wall (11a) of the body (11) is covered with a hydrophilic film (3).

6. Cover (1) according to any one of claims 1 to 5, in which the seal (12) comprises one or more thermoplastic elastomer(s).

7. A lid (1) according to any one of claims 1 to 6, wherein the seal (12) is overmolded onto the body (11) or wherein the seal (12) was co-injected with the body (11).

8. A food container (100) comprising a lid (1) according to any preceding claim and a container (2).

9. Food container (100) according to claim 8, wherein the inner wall(s) (2b) of the container (2) are covered by a hydrophilic film.

10. Food container (100) according to any one of claims 8 to 9 wherein the outer wall(s) (2a) of the container (2) are covered by a hydrophilic film.

11. Use of a hydrophilic film for covering at least a portion of the exterior of a seal (12) and at least a portion of the interior wall (11b) of the plastic body (11) of a lid (1) of a food container (100), to increase the sealing of the food container (100) and / or reduce the compression force to be applied by the user when locking and / or unlocking the lid (1).

12. A method of manufacturing a cover (1) according to any one of claims 1 to 7 comprising the following successive steps: a) providing a plastic body (11) having a seal (12) assembled to the inner wall (11b) of the body (11), b) simultaneously covering at least a portion of the inner wall (11b) of the body (11) and at least a portion of the exterior of the seal (12) with a hydrophilic film (3).

13. Method according to claim 12, in which the method comprises a step a.0) of manufacturing the body (11) by injection or co-injection.

14. Method according to claim 13, in which the method comprises a step al) of overmolding the seal (12) on the inner wall (11b) of the body (11) or of manufacturing the seal (12) by co-injection with the body (H).

15. A method according to any one of claims 12 to 14, wherein, in step b), a coating comprising one or more elements selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminum oxides, amorphous carbon, and mixtures thereof, is applied to the inner wall (11b) of the body (11) and to the seal (12) by plasma-enhanced chemical vapor deposition (PECVD).

16. The method of claim 15, wherein a siloxane or disiloxane precursor is used for the chemical phase deposition. plasma-assisted vapor deposition (PECVD), preferably hexamethyldisiloxane (HDMSO).

17. Method according to any one of claims 12 to 16, in which step b) comprises a step of simultaneous surface treatment of at least a portion of the inner wall (11b) and at least a portion of the exterior of the seal (12) by plasma of one or more non-polymerizable gas(es).

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