food container lid comprising a hydrophilic film

Abstract

Lid (1) of 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 partially covered with a hydrophilic film (3) and in that the exterior of the seal (12) is at least partially covered with a hydrophilic film (3). Figure for the abstract: Figure 2.

Description

Title of the invention: Food container lid comprising a hydrophilic film FIELD OF 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. PRIOR TECHNOLOGY

[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 on the lid, a compression caused by the user when locking it. This requires the user to exert some effort when locking and then unlocking the lid.

[0004] Known seals are generally made of plastics or silicone elastomers. When used in food container seals, these materials have an operating temperature above their glass transition temperature. This allows the seals to be sufficiently deformable to conform to the geometry of the lid. However, it is known that above the glass transition temperature, these materials have a significant free volume, which promotes diffusion phenomena that compromise the seal of the food container after a storage period of 24 hours. To maintain the seal, the locking force required from the user must therefore be high.

[0005] If the effort required by the user to compress the seal is too great, 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 effort required from the user generally results in a decrease in the compression of the lid seal, and therefore makes the food container less airtight.

[0007] The lids of known food containers are generally made of plastic materials, which naturally have a low surface tension. This low surface tension promotes the dewetting phenomenon, that is, the process by which the contact area between the solid and the wetting film spontaneously reduces.

[0008] It is known that the demolding phenomenon can be advantageous for ensuring good sealing of food containers, because the contact between the sealing area The container and food liquids are made more concentrated (food liquids form droplets on the surface of the lid). Furthermore, the use of plastic materials allows for the manufacture of lids with complex geometric shapes using established injection molding techniques.

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

[0010] In addition, 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 leakage if the compression of the cover seal is not sufficient.

[0011] Thus, there is a need to develop improved food container lids, which ensure a good seal while overcoming the drawbacks described. Description of the invention

[0012] The applicant has developed a lid with advantageous properties. Surprisingly, it has demonstrated that the presence of a hydrophilic film on at least part of the outside of the seal and on at least part of the inner wall of the lid ensures a good seal for the food container and reduces the effort required by the user when locking or unlocking the lid.

[0013] The described invention also has one of the following advantages: - to ensure a good seal against water and / or oil, particularly during the transport of the food container; - to 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 lid 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 growth during the aging of the food container; - to allow the manufacture of a watertight lid in a limited number of steps, the seal being able to be assembled to the lid (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, a food container lid is proposed 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 outside of the seal is at least partly covered with a hydrophilic film.

[0015] According to advantageous and non-limiting features, 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, aluminium oxides, amorphous carbon, and mixtures thereof; - the inner wall of the body and the outside of the seal have been subjected to a plasma treatment of one or more non-polymerizable gas(s) to form the hydrophilic film; - The body comprises polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), glycolized polyethylene terephthalate (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrin copolymer (SAN), translucent or opaque acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), poly(butylene terephthalate) (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), poly(methyl methacrylate) (PMMA), copolyesters (including Tritan™ synthesized from dimethyl terephthalate, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanedimethanol monomers), and crystal polymers liquids (LCP), 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, a food container is proposed comprising a lid as previously presented and a container.

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

[0018] According to a third aspect, it is also proposed to use a hydrophilic film to cover 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 sealing of the food container and / or decrease the compression force to be applied by the user when locking and / or unlocking the lid.

[0019] According to a fourth aspect, a manufacturing process for a lid as described above is proposed, comprising the following successive steps: a) provide a plastic body having a seal assembled to the inner wall of the body, b) simultaneously cover at least part of the inner wall of the body and at least part of the outside of the seal with a hydrophilic film.

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

[0021] - the process includes a step al) of overmolding the seal onto the inner wall of the body or of manufacturing the joint by co-injection with the body;

[0022] - in step b), a coating comprising one or more element(s) selected from the a group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminium 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) includes a simultaneous surface treatment step of at least one part of the inner wall of the body and at least part of the outside of the joint by plasma of one or more non-polymerizable gas(s).

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

[0026] Other features and advantages of the present invention will become apparent from the following description of a preferred embodiment. This description will be given with reference to the accompanying figures, including: - Fig. 1 illustrates a food container comprising a lid and a receptacle - [Fig.2] illustrates a lid of a food container; - [Fig.3] is a cross-sectional view of a food container; - Fig. 4 represents the steps in a manufacturing process for a food container lid. Definitions

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

[0028] For the purposes of this invention, the term "film" means a continuous layer, that is, a single, flat layer covering the desired surface. A film may be single-layered or multi-layered. The term "film" includes, in particular, for the purposes of this invention, any layer formed by modifying 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 it covers. This will notably be the case when the film is formed by a surface treatment.

[0029] By "hydrophilic film", we mean, in the context of the present invention, a film having a surface tension greater than the surface tension of the material on which it is affixed.

[0030] The term "seal" refers to a gasket that ensures the sealing of the assembly of fixed or moving parts. In this case, the seal 12 is intended 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 airtight when the lid 1 is assembled to the container 2. Further characteristics of the seal 12, such as its constituent material(s) or its shape, will be detailed below. Detailed description of the invention: Lid

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

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

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

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

[0035] Advantageously, the food container 100 includes means for attaching, advantageously reversibly, the lid 1 to the container 2. In other words, the means for attaching the lid 1 to the container, preferably even when the food container 100 is moved or changed in orientation (for example turned over).

[0036] According to an embodiment illustrated in Figures 1 to 3, the fastening 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 secure the lid 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 lid 1 and the female parts 42 take the form of a protruding part 42 of the container 2. The protruding part 42 projects from the container 2. In this case, the lid 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 come engage against the protruding part 42 so as to fix the lid 1 to the container 2.

[0037] Other embodiments of the fastening means 4 can be envisaged. Those skilled in the art are aware of various types of fastening means 4 suitable for the food container 100. For example, the male part 41 and the female part 42 of the fastening means 4 may be threaded. The lid 1 may include a thread, and the container 2 may include a thread complementary to the thread of the lid 1, so that the lid 1 is thus adapted to be screwed onto 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 polymers selected 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-acrylonitrin copolymer (SAN), translucent or non-translucent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), poly(butylene terephthalate) (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), poly(methyl methacrylate) (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-l,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, the body 11 of the lid 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, it is understood that the seal 12 preferably has a thickness of 15 mm or less, or 10 mm or less. The strip, i.e., the seal 12, can have different shapes; for example, it can be straight, elliptical, circular, rectangular, etc.

[0041] Advantageously, the shape of the seal 12 depends on the shape of the portion of the container 2 that is adapted to be in contact with the seal 12 when the lid 1 is placed 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 ensures the sealing of the food container 100.Indeed, it is desirable that the seal 12 run 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 inside of the container) so that there is no fluid communication between the cavity 20 of the container 2 and the container 100. the external environment.

[0042] Advantageously, the joint 12 forms a continuum so as to delimit a closed area of ​​the inner wall 11b of the body 11. This closed area is advantageously the main part 111b of the inner wall 11b of the body 11 which has been presented previously.

[0043] Advantageously, the seal 12 comprises one or more polymers selected from the group consisting of rubbers, silicones, and thermoplastic elastomers (TPEs). Advantageously, the seal 12 comprises more than 50% by weight of one or more thermoplastic elastomers (TPEs), 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 bonding, 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 part of the inner wall of the body 11b and at least a part of the outside of the seal 12 according to the invention are covered with a hydrophilic film 3.

[0048] At least part of the inner wall of the body 11b is covered with a hydrophilic film 3. The entire inner wall 11b of the body, that is to say the whole of the inner wall 11b, can be covered by a hydrophilic film 3. Advantageously, the whole of the inner wall 11b, except for the part in contact with the seal 12, is covered by a hydrophilic film. Indeed, when the body 11 and the seal 12 are assembled prior to the application 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 that is accessible, that is to say the entire part that 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 that is defined when the seal 12 is assembled to the body 11. By "exterior of the seal 12," it is understood that the part of the seal 12 is exposed to the external environment when the lid 1 is not assembled to a container 2. In other words, the exterior of the seal 12 is not a The outer part of the seal 12 is the portion of the seal 12 that is in contact with the body 11 of the lid 1. The outer part of the seal 12 is the portion of the seal 12 that is directly visible. Directly visible is the opposite of indirectly visible, i.e., visible only through the body 11 if the latter is transparent. The outer part of the seal 12 is a portion of the seal 12 that is adapted to be at least partially in contact with the container 2 and possibly opposite the inside of the container 2 when the lid 1 is assembled to the container 2. In other words, the outer part of the seal 12 is a portion of the seal 12 that is likely to be covered with a hydrophilic film 3 since this portion of the seal 12 is accessible.

[0050] At least part of the outside of the seal 12 is covered with a hydrophilic film 3. The entire outside of the seal 12, that is to say the whole outside of the seal 12, can 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 outside 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, we can mention in particular metallic, mineral, ceramic coatings, and more particularly coatings based on aluminium, silicon and / or carbon.

[0054] Preferred coatings according to the invention are coatings comprising one or more elements selected 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 outside of the seal 12.

[0055] According to another embodiment, the hydrophilic film 3 consists of a layer formed as a result of a modification of the molecular chains of the materials composing the surface considered.

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

[0057] The chemical nature of the hydrophilic film 3 formed following a surface modification depends on the nature of the treatment applied and the nature of the materials composing the treated surface. For example, the use of a plasma treatment using nitrogen would lead to the formation of a hydrophilic film 3 comprising nitrogenous hydrocarbon ions (CN, CxHyN) and oxygenated nitrogen 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 previously shown 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], container 2 defines a cavity in which food can be placed. Container 2, and therefore its cavity 20, can have any type of shape. For example, container 2 can be parallelepiped-shaped.

[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 can be mainly made of metal, glass or plastic materials.Advantageously, container 2 comprises one or more polymers selected 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-acrylonitrin copolymer (SAN), translucent or opaque acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), poly(butylene terephthalate) (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), poly(methyl methacrylate) (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-l,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, 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, container 2 comprises more than 99% by weight of polypropylene. (PP).

[0064] Advantageously, the inner wall(s) of the container 2 are coated with a hydrophilic film 3 according to the invention. In one embodiment, the container 2 is not coated with a hydrophilic film, particularly 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 as, 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 as, 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 applicable, 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 1 of the body 11 of the lid 1, where applicable. Use

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

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

[0068] The leak-tightness of the food container 100 can be measured using the following technique: the container is filled with a liquid, the lid is placed on top and locked, and then the container is positioned vertically. A leak can thus be detected in this vertical position. "Vertically" means that the container is positioned on one of its side walls. In other words, the container is placed on a surface, preferably a flat one, so that one of the container's side walls is in contact with the surface. To put it another way, when the container is positioned vertically, it is not placed in the conventional manner; that is, the bottom of the container is not in contact with the surface on which it 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 for manufacturing a lid 1 according to the invention is proposed, comprising the following successive steps:

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

[0072] b) simultaneously cover at least part of the inner wall of the body 11 and at least part of the outside 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 polymers selected 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-acrylonitrin copolymer (SAN), translucent or non-translucent acrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), poly(butylene terephthalate) (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), poly(methyl methacrylate) (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-l,3-cyclobutanediol and 1,4-cyclohexanedimethanol), liquid crystal polymers (LCPs), or mixtures thereof.Advantageously, the body 11 of the lid 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 supplied 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 process includes 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 polymers selected from the group consisting of rubbers, silicones, and thermoplastic elastomers (TPEs). 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 body 11 has been manufactured. As explained previously, this assembly can, for example, be carried out by bonding, 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 process includes 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. The steps a.0) and a. 1) can therefore be successive or simultaneous. Step b)

[0080] Step b) consists of covering at least a part of the inner wall of the body 11 and at least a part of the outside 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), except for 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 a part of the inner wall of the body 11 and at least a part of the outside of the seal 12 are covered simultaneously with the same hydrophilic film 3. It is also conceivable to cover the inner wall of the body 11 and at least a part of the outside 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 a mixture thereof to form a hydrophilic film 3 on the surface.

[0086] Among surface treatments, plasma treatment using nitrogen is 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 a hydrophilic coating according to the invention to the inner wall of the body 11 and to the seal 12.

[0088] Advantageously, the applied coating comprises one or more element(s) selected 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), siloxane or disiloxane-type precursors are preferably used, possibly 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 can be carried out before coating deposition (for example, to facilitate adhesion) or after coating deposition (for example, to enhance the hydrophilicity of the coating).

Claims

Demands

1. Lid (1) of 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 outside of the seal (12) is at least partly covered with a hydrophilic film (3).

2. Lid (1) according to claim 1, wherein the hydrophilic film (3) is a coating comprising one or more element(s) selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminium oxides, amorphous carbon, and mixtures thereof.

3. Lid (1) according to claim 1, wherein the inner wall (11b) of the body (11) and the outside of the seal (12) have been subjected to a plasma treatment of one or more non-polymerizable gas(s) 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), glycolized polyethylene terephthalate (PETG), polyamide (PA), polystyrene (PS), polycarbonate (PC), styrene-acrylonitrin copolymer (SAN), translucent or non-translucent racrylonitrile butadiene styrene (ABS), polyacrylic acid (PAA), polyoxymethylene (POM), poly(butylene terephthalate) (PBT), polylactic acid (PLA), polyetheretherketone (PEEK), poly(methyl methacrylate) (PMMA), copolyesters (in particular Tritan™ synthesized from dimethyl terephthalate monomers, 2,2,4,4-tetramethyl-l,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 (1la) of the body (11) is covered with a hydrophilic film (3).

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

7. 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 field (11).

8. Food container (100) comprising a lid (1) according to any one of the preceding claims and a receptacle (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 in which the outer wall(s) (2a) of the container (2) are covered by a hydrophilic film.

11. Use of a hydrophilic film to cover at least part of the outside of a seal (12) and at least part of the inner 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 decrease the compression force to be applied by the user when locking and / or unlocking the lid (1).

12. A method for manufacturing a lid (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 part of the inner wall (11b) of the body (11) and at least a part of the outside of the seal (12) with a hydrophilic film (3).

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

14. Method according to claim 13, wherein the method includes a step a1) of overmolding the seal (12) onto 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 element(s) selected from the group consisting of silicon oxides, silicon nitrides, silicon oxynitrides, aluminium 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. A method according to claim 15, wherein a precursor of the siloxane or disiloxane type is used for chemical phase deposition plasma-assisted vapor (PECVD), preferably hexamethyldisiloxane (HDMSO).

17. A method according to any one of claims 12 to 16, wherein step b) comprises a step of simultaneous surface treatment of at least a part of the inner wall (11b) and at least a part of the outside of the joint (12) by plasma of one or more non-polymerizable gas(s).

Images