A multi-layer material that can be used as a packaging material, comprising a layer of cellulosic material and a layer of a material containing at least one casein and / or at least one caseinate.

Abstract

The present invention relates to the field of multilayer materials that can be used as packaging materials. The aim of the present invention is to provide a material that is based on cellulosic materials, is recyclable, bio-based, biodegradable and / or has improved barrier properties, can be used as packaging materials, for example in the food sector, and is preferably easy to produce. In particular, the present invention relates to a multi-layer material comprising a layer of a cellulosic material A and a layer of material B comprising at least one casein and / or at least one caseinate, water, and at least one plasticizer other than water, and optionally gelatin. The invention also relates to packaging materials made from this material, products packaged with this packaging material, and methods for making this material.

Description

[Technical field]

[0001]

[0001] The present disclosure relates to the field of multi-layer materials that can be used as packaging materials. In particular, the present disclosure relates to a multi-layer material comprising a layer of a cellulosic material A and a layer of a material B that comprises at least one casein and / or at least one caseinate. [Background technology]

[0002]

[0002] The increasing scarcity of non-renewable resources such as oil and the growing pollution associated with these resources has led to the development of less polluting and more environmentally friendly alternative solutions. With regard to packaging in particular, the European Commission wants 100% of packaging to be reusable, mechanically recyclable or compostable by 2030 (Circular Economy Action Plan-2020).

[0003]

[0003] In the food sector, the use of packaging materials made from potentially recyclable cellulosic materials, such as paper or cardboard packaging materials, is increasing. However, there are still significant obstacles to the recyclability of these packaging materials. Furthermore, the use of recycled paper in these packaging materials may also pose problems for consumer safety.

[0004]

[0004] In fact, disposable packaging for takeaways and fast food always has a plastic layer as an anti-grease barrier, generally made of polyamide (PA) or perfluoroalkyl substances (PFAS), for the convenience of the consumer, which corresponds to 65,000 tonnes of waste in Europe every year (amounting to 2,025 million packaging units produced).

[0005]

[0005] Furthermore, 17% of paper packaging materials are provided with a plastic layer (made of PE, PP, PET, PVDC, EVOH or PVOH) to provide a barrier against gas, grease or water to reveal the food inside or to allow hermeticity (closure of the package).

[0006]

[0006] In addition, recycled paper cannot be used in direct contact with food due to the migration of mineral oils from inks used on previous papers, e.g. newspapers. For consumer safety, a layer of plastic must be used as a barrier here too. This prevents the widespread use of recycled paper in food packaging.

[0007]

[0007] When this packaging material is sorted, removing the plastic layer from the paper is a real problem at recycling centers, resulting in, at best, a loss of 10-20% of the paper fibers, and at worst, contamination of the fiber batch with plastic which then has to be incinerated or landfilled. Summary of the Invention [Problem to be solved by the invention]

[0008]

[0008] Therefore, there is a need to develop a packaging material that can overcome these drawbacks.

[0009] In this context, the present invention aims to meet at least one of the following objectives:

[0009]

[0010] One of the objects of the present invention is to provide a recyclable material that can be used as packaging material.

[0011] One of the aims of the present invention is to provide a bio-based, recyclable material that can be used as packaging material.

[0010]

[0012] One of the aims of the present invention is to provide a recyclable material that can be used as packaging in the food sector.

[0013] One object of the present invention is to provide a biodegradable material that can be used as a packaging material.

[0011]

[0014] Another object of the present invention is to provide a cellulosic-based material having improved barrier properties.

[0015] One of the aims of the present invention is to provide a recyclable material that is easily produced. [Means for solving the problem]

[0012]

[0016] The present disclosure relates to i) at least one layer of cellulosic material A, and ii) a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) At least one layer of material B containing The present invention relates to a multi-layer material including

[0013]

[0017] The present disclosure also provides a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) coating with a solution S comprising: or a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) with a layer of material B, optionally with a binder, preferably by carrying out compounding or lamination, The present invention relates to a multilayer material obtained by any of the following methods:

[0014]

[0018] The present disclosure also relates to packaging materials that include the multi-layer material.

[0019] The present disclosure is also directed to products packaged with packaging materials that include the multi-layer material.

[0020] The present disclosure also relates to a method of making a multi-layer material, the method comprising: a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) Coating with a solution comprising: or a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) with a layer of material B, optionally with a binder, preferably by carrying out a compounding or lamination process, This is carried out by either

[0015]

[0021] The inventors have discovered that such a multi-layer material can be used as a packaging material. In fact, this multi-layer material can be recycled in recycling centers without any modification of the lines or methods, since the layer of material B is water-soluble. In the recycling center, the cellulosic material fibers can be almost 100% recovered by simple mechanical filtration. The residues of material B resulting from the solubilization of material B are biodegraded in the water treatment infrastructure already installed in the recycling plant. The fact that the residues of material B are biodegradable makes it possible to avoid the pollution associated with microplastics.

[0016]

[0022] Furthermore, the presence of the material B layer makes it possible to improve the barrier properties of the multilayer material, especially the barrier properties against grease and oxygen, making it possible to consider its use in the food packaging sector.

[0017]

[0023] The multi-layer material according to the invention also has good weldability, especially heat sealability.

[0024] The multi-layer material according to the invention thus combines good recyclability, improved barrier properties and good weldability, which allows it to be used as packaging material, especially in the food sector.

[0018]

[0025] Furthermore, material B is safe for contact with food, 100% renewable, compostable and biodegradable in the marine environment, which is not the case for most polymers used in packaging. Casein is an existing ingredient, proven in the food industry and easily industrializable. Thus, multi-layer materials can be easily produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019]

[0026] Unless otherwise specified, in this specification, % is expressed by weight %.

[0027] "packaging" means any object intended to contain and protect a commodity, to enable its handling and transport from producer to consumer or user, as well as to enable its presentation, its preservation, its protection and / or its use;

[0020]

[0028] By "cellulosic material" is meant, for example, a material that can be obtained from cellulose pulp. The cellulose pulp can be produced by chemical and / or mechanical processes well known to those skilled in the art. The cellulose pulp can be obtained from any suitable source, such as wood, recycled wood, annual plants, agricultural residues (bagasse, straw, etc.), grasses (e.g. sugar cane, bamboo) or cardboard.

[0021]

[0029] "Thermoplastic" refers to a material that becomes flexible and foldable at a certain temperature, for example above the glass transition temperature Tg, but becomes rigid again below this Tg, and these transformations are reversible.

[0022]

[0030] "Biodegradable" means, for example, a material that can be decomposed by the action of microorganisms (bacteria, fungi, algae, etc.). This decomposition results in the accumulation of water, CO2 and / or methane, and possibly environmentally harmless by-products (residues, new biomass). It is, for example, a biodegradable material according to the European standards EN NF13432 and / or NF T51-800.

[0023]

[0031] "Between x and y" means, for example, that the boundaries x and y are included in the interval [x, y].

[0032] "Water soluble" means, for example, soluble in water. The water solubility of a material can be measured as follows: a piece of film (5 cm x 5 cm, cut using a die) is fixed in a photographic slide holder and immersed in a beaker of 1000 ml capacity containing 600 ml of distilled water at 20°C, stirred with a magnetic bar at 300 rpm. The time until the film bleeds through ("se percer" in French) is measured. The breakdown of the film results in the formation of film particles. The test lasts for 10 minutes, after which the particles are passed through a 0.5 mm sieve to measure the particle size. If there are no particles in the sieve, the film is considered water soluble.

[0024]

[0033] "Plasticizer" refers, for example, to a substance capable of lowering the glass transition temperature, Tg, of a material.

[0034] "Hydrophobic" refers, for example, to compounds that have a low affinity for water and tend not to dissolve therein. Typically, these are primarily non-polar compounds.

[0025]

[0035] "Hydrophilic" refers, for example, to a compound that has an affinity for water and tends to dissolve therein, typically a compound that has polar groups capable of forming hydrogen bonds.

[0026]

[0036] "Surfactant" refers, for example, to an amphiphilic molecule, ie, a molecule that has both hydrophilic and hydrophobic properties.

[0037] "HLB" for example means hydrophilic-lipophilic balance. The HLB value can be calculated in the following way: HLB = 20 x (molar mass of the hydrophobic part) / (molar mass of the molecule).

[0027]

[0038] "Fatty acid" refers, for example, to an aliphatic monocarboxylic acid.

[0039] "Bio-based" refers, for example, to products made from materials derived from living organisms.

[0028]

[0040] By "binder" is meant, for example, an agent making it possible to form an adhesive layer between a layer of cellulosic material A and a layer of material B. The binders used in the invention can be binders conventionally used in the manufacture of multilayer materials, in particular multilayer films. Among binders, mention may be made of hot melt adhesives (in French "colles thermofusibles").

[0029] multilayer material

[0041] The present invention first provides a method for producing a i) at least one layer of cellulosic material A, and ii) a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) At least one layer of material B containing The present invention relates to a multi-layer material comprising:

[0030]

[0042] The present disclosure also provides a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) Coating with a solution S comprising or a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) with a layer of material B, optionally with a binder, preferably by carrying out compounding or lamination, The present invention relates to a multilayer material obtained by any of the following methods:

[0031]

[0043] The multi-layer material is preferably recyclable and / or bio-based. The multi-layer material may be recyclable according to Directive 2018 / 852 / EU of 30 May 2018. According to an embodiment, the multi-layer material is compostable, preferably according to the NF T51-800 standard.

[0032]

[0044] The multilayer material may have a thickness between 0.01 and 100 mm, preferably between 0.05 and 50 mm.

[0045] The cellulose-based material A is preferably selected from paper and cardboard. According to an embodiment, the cellulose-based material A has a basis weight between 20 and 500 g / m2, preferably between 50 and 450 g / m2. According to an embodiment, the cellulose-based material A is selected from paper having a basis weight between 20 and 225 g / m2 and cardboard having a basis weight between 225 and 500 g / m2.

[0033]

[0046] The layer of cellulosic material A may have a thickness between 0.01 and 50 mm, preferably between 0.05 and 20 mm.

[0047] The cellulosic material A preferably comprises at least 80% by weight, more preferably at least 90% by weight, of cellulose.

[0034]

[0048] The cellulosic material A may be coloured and may comprise a pigment layer, The cellulosic material A may comprise a mineral layer, for example of the kaolin type.

[0049] Material B and / or solution S are a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) Includes.

[0035]

[0050] Casein is a milk-derived protein that is poorly soluble in water. It is mainly obtained by precipitation from milk with the addition of acid (acid casein) or rennet (rennet casein) or by filtration (micellar casein). Casein consists of a mixture of α-casein, β-casein and κ-casein with a molar mass between 19,000 and 25,000 g / mol. Caseinate means, for example, a caseinate whose countercation is selected from the group including, preferably consisting of, calcium, potassium, ammonium, sodium and magnesium.

[0036]

[0051] According to another embodiment, a) comprises at least one caseinate, such as sodium caseinate, or a mixture of caseinates.

[0052] According to another embodiment, a) comprises a mixture of casein and at least one caseinate, in which case the mass ratio of casein to caseinate(s) can be between 5 / 95 and 95 / 5, between 20 / 80 and 80 / 20, or between 40 / 60 and 60 / 40.

[0037]

[0053] The material B and / or the solution S may contain gelatin d).

[0054] Gelatine is a protein rich in glycine and proline. It is obtained by partial hydrolysis of collagen, mainly from collagen found in animal skins and bones. It can be type A (collagen treated with acid) and type B (collagen treated with base). It can also be obtained by enzymatic treatment of collagen. The gelatine used is preferably not chemically modified. According to an embodiment of the invention, the gelatine used is commercial or type B food gelatine, which can be in the form of sheets, powder or granules. Advantageously, the gelatine used is type B.

[0038]

[0055] When d) is included, the ratio of the amounts a):d) may be between 90:10 and 20:80, preferably between 75:25 and 25:75, preferably between 60:40 and 40:60. According to a particular embodiment, the ratio a):d) is 50:50. According to a particular embodiment, the ratio a):d) is between 55:45 and 45:55.

[0039]

[0056] The plasticizer c) may be selected from polyols, glycerol acetate, glycerol propionate and mixtures thereof.

[0057] Examples of polyols include glycols, including glycerol, hexanetriol, ethylene glycol, and sugars and their derivatives.

[0040]

[0058] Examples of sugars include disaccharides such as maltose, lactose, sucrose, and monosaccharides such as fructose.

[0059] Among the sugar derivatives, mention may further be made of hydrogenated derivatives such as sorbitol, maltitol, mannitol and xylitol, or the conversion products of these hydrogenated derivatives, such as sorbitan.

[0041]

[0060] According to an embodiment, the plasticizer c) is selected from glycerol, sorbitol, mannitol, ethylene glycol and mixtures thereof. Preferably, the plasticizer c) is selected from glycerol, sorbitol and mixtures thereof. According to an embodiment, the plasticizer c) is glycerol.

[0042]

[0061] The plasticizer c) may contain residual water.

[0062] Plasticizers c) make it possible to reduce the viscosity of the product by increasing the mobility of the molecular chains.

[0043]

[0063] Advantageously, the plasticizer c) is a hydrophilic plasticizer.

[0064] The material B and / or the solution S may also contain a hydrophobizing agent e). The hydrophobizing agent e) is -polybasic carboxylic esters (carboxylic polyacid esters); - C3-C33 carboxylic acids, preferably C4-C28 fatty acids, more preferably C6-C28 unsaturated fatty acids; - and mixtures thereof You can choose from.

[0044]

[0065] The polybasic carboxylic acid esters can be derived from at least one polybasic carboxylic acid and at least one alcohol, preferably a C1-C18 alcohol.

[0066] Among the polybasic carboxylic acids which are preferentially selected within the scope of the present invention, mention may be made of citric acid, hydroxycitric acid, tartaric acid, malic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid and fumaric acid.

[0045]

[0067] Among the alcohols preferred according to the invention, mention may be made, for example, of C2-C6 alcohols such as ethanol, n-propanol, iso-propanol, n-butanol and tert-butanol.

[0046]

[0068] According to an embodiment, the hydrophobizing agent e) is chosen from triethyl citrate, tributyl O-acetylcitrate, tributyl citrate and mixtures thereof.

[0069] According to an embodiment, the hydrophobizing agent e) is a C3-C33 carboxylic acid, preferably a C4-C28 fatty acid, more preferably a C6-C28 unsaturated fatty acid.

[0047]

[0070] Among the C4-C28 fatty acids selected within the framework of the present invention, mention may be made of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and mixtures thereof.

[0048]

[0071] Among the C6-C28 unsaturated fatty acids of particular interest are palmitoleic acid, oleic acid, linoleic acid, and mixtures thereof.

[0072] Material B and / or solution S may further comprise at least one surfactant f), preferably selected from zwitterionic surfactants with an HLB between 2 and 8.

[0049]

[0073] Among the preferred surfactants, lecithin and / or its analogues, such as diacetylene phosphonates, and polysorbates can be mentioned. Polysorbates are esters of fatty acids and polyoxyethylene sorbitan. Among the polysorbates, polysorbate 20, polysorbate 40, polysorbate 60 and polysorbate 80 can be mentioned.

[0050]

[0074] According to an embodiment, the ratio of the amounts of f) and e) is greater than or equal to 1. For example, this ratio may be between 1.3 and 3, preferably between 1.5 and 2.5.

[0075] Material B and / or solution S may also contain a polysaccharide g). Preferably, g) is selected from pullulan, starch, alginate, and mixtures thereof. Polysaccharide g) may be a water-soluble polysaccharide.

[0051]

[0076] The material B and / or the solution S may further comprise a bittering agent h), preferably denatonium benzoate.

[0077] The bittering agent h) may be selected from denatonium benzoate, denatonium benzoate derivatives, denatonium saccharide, denatonium chloride, sucrose benzoate, quinine, quinine hydrochloride, quinine sulfate, brucine, brucine sulfate, quassia, quasin, naringin, limonin, phenylthiocarbamide, quebracho, sucrose octaacetate, quercetin, berberine, and mixtures thereof.

[0052]

[0078] According to an embodiment, material B and / or solution S also contain additives i) selected from dyes, protein coagulants, anti-caking agents, lubricants and mixtures thereof. Among the coagulants, mention may be made of citric acid and acetic acid. Among the anti-caking agents, mention may be made of colloidal silica. Among the lubricants, mention may be made of polyethylene glycols and compounds with fatty chains, preferably C12 to C28, having amide end groups.

[0053]

[0079] According to an embodiment, material B and / or solution S comprises an additive j) chosen from sequestering agents. By "sequestering agent" is meant a ligand that forms a chemical complex with metal ions, such as, for example, copper, iron, nickel, calcium and magnesium. Among the sequestering agents, mention may be made of diammonium citrate, EDTA, phosphates, citric acid, pyrophosphates and mixtures thereof.

[0054]

[0080] The proportions of the different components of material B are expressed in % by weight relative to the total weight of material B at room temperature. According to an embodiment, material B comprises between 10 and 80%, preferably between 20 and 75%, further preferably between 25 and 70% of casein and / or caseinates a).

[0055]

[0081] According to an embodiment, material B comprises between 50 and 80%, preferably between 52 and 75%, further preferably between 55 and 70% of casein and / or caseinates a), According to an embodiment, material B comprises between 10 and 55%, preferably between 20 and 50%, further preferably between 25 and 40%, further preferably between 30 and 35% of casein and / or caseinates a).

[0056]

[0082] According to an embodiment, material B comprises between 1 and 55%, preferably between 5 and 50%, preferably between 10 and 40%, more preferably between 30 and 35% gelatin d).

[0083] According to a particular embodiment, material B comprises between 30 and 35% casein and / or caseinates a) and between 30 and 35% gelatin d).

[0057]

[0084] Material B may contain between 5 and 15% water b), preferably between 7 and 11%. The amount of water may be set between 9 and 10%. Water acts as a plasticizer that must be differentiated from the plasticizer c) that enters into the composition of material B.

[0058]

[0085] Material B may contain between 10 and 35%, preferably between 15 and 30%, of at least one plasticizer c) different from c).

[0086] Material B may contain between 0.1 and 8%, preferably between 1 and 4%, of hydrophobizing agent e). Advantageously, material B contains between 0.5 and 6%, preferably between 1 and 3%, of hydrophobizing agent e).

[0059]

[0087] Material B may contain between 0.5 and 6% of at least one surfactant f), preferably chosen from zwitterionic surfactants with an HLB between 2 and 8. Advantageously, material B may contain between 1 and 5%, preferably between 1.5 and 4.5%, and even better between 2 and 4% of at least one surfactant f).

[0060]

[0088] Material B may contain between 2 and 10% polysaccharides g), preferably chosen from pullulan, starch, alginates and mixtures thereof. Advantageously, material B contains between 4 and 8% polysaccharides g).

[0061]

[0089] Material B may contain between 0.001 and 0.5% of a bittering agent h), preferably denatonium benzoate. Advantageously, material B further contains between 0.05 and 0.15% of a bittering agent h).

[0062]

[0090] Material B may contain between 0.1% and 5% of i) Material B may contain between 1 and 5% of an additive j) selected from sequestering agents.

[0091] Material B may be water-soluble and / or biodegradable. Material B may be bio-based. According to an embodiment, material B is a thermoplastic material. Material B may be obtained by extrusion, as described in the examples.

[0063]

[0092] According to an embodiment, the layer of material B is a film layer of material B, preferably a thermoplastic, biodegradable and water-soluble film layer of material B. Typically, the film layer of material B has a thickness between 1 and 150 microns, preferably between 2 and 50 microns, more preferably between 2.5 and 20 microns.

[0064]

[0093] The proportions of the different constituents of solution S are expressed in % by weight relative to the total weight of dry matter in solution S. According to an embodiment, solution S comprises a dry matter content between 0.1 and 90%, preferably between 1 and 50%, preferably between 5 and 25%, more preferably between 10 and 20%. Solution S can be obtained by solubilizing material B in water or by solubilizing the different constituents in water.

[0065]

[0094] According to an embodiment, the solution S comprises between 10 and 80%, preferably between 20 and 75%, and even more preferably between 25 and 70% of casein and / or caseinates a).

[0066]

[0095] According to an embodiment, solution S comprises between 50 and 80%, preferably between 52 and 75%, further preferably between 55 and 70% of casein and / or caseinates a), According to an embodiment, solution S comprises between 10 and 55%, preferably between 20 and 50%, preferably between 25 and 40%, further preferably between 30 and 35% of casein and / or caseinates a).

[0067]

[0096] According to an embodiment, the solution S comprises between 1 and 55%, preferably between 5 and 50%, preferably between 10 and 40%, and even more preferably between 30 and 35% gelatin d).

[0097] According to a particular embodiment, solution S comprises between 30 and 35% casein and / or caseinates a) and between 30 and 35% gelatin d).

[0068]

[0098] Solution S may contain between 10 and 35%, preferably between 15 and 30%, of at least one plasticizer different from c).

[0099] Solution S may contain between 0.1 and 8% of hydrophobizing agent e), preferably between 1 and 4%. Advantageously, solution S contains between 0.5 and 6%, preferably between 1 and 3%, of hydrophobizing agent e).

[0069]

[0100] Solution S may contain between 0.5 and 6% of at least one surfactant f), preferably chosen from zwitterionic surfactants with an HLB between 2 and 8. Advantageously, solution S may contain between 1 and 5%, preferably between 1.5 and 4.5%, and even better between 2 and 4% of at least one surfactant f).

[0070]

[0101] Solution S may contain between 2 and 10% of polysaccharides g), preferably chosen from pullulan, starch, alginates and mixtures thereof. Advantageously, solution S contains between 4 and 8% of polysaccharides g).

[0071]

[0102] Solution S may contain between 0.001 and 0.5% of a bittering agent h), preferably denatonium benzoate. Advantageously, solution S also contains between 0.05 and 0.15% of a bittering agent h).

[0072]

[0103] The solution S may contain between 0.1% and 5% of i) The solution S may contain between 1 and 5% of an additive j) chosen from sequestering agents.

[0104] Solution S may also contain preservatives and / or biocides. The concentration of the preservatives and / or biocides may be between 0.1 and 5%. Packaging materials containing multi-layered materials

[0105] The present disclosure also relates to packaging materials that include the multi-layer material. In some cases, the packaging materials include layers other than the multi-layer material, and in other cases, the packaging materials are made of the multi-layer material.

[0073]

[0106] The present disclosure is also directed to the use of the multi-layer material for packaging various products (medicines, food, chemicals, cosmetics, etc.).

[0107] The present disclosure is also directed to products packaged with packaging materials that include the multi-layer material.

[0074]

[0108] The product can be in the form of a solid, liquid, or gel. The packaged product can be anything, such as a machine part, a DIY item, a gardening item, a magazine, a newspaper, or a disposable dish.

[0075]

[0109] The packaged product may be selected from, for example, pharmaceuticals, food products, chemical products, and cosmetics.

[0110] According to an embodiment, the packaged product is a food product, such as, for example, meat, fish, vegetables, fruit, bakery goods, viennoiserie, chocolate, confectionery, food additives, food ingredients, dry preparations, food powders, prepared meals, etc.

[0076]

[0111] According to an embodiment, the packaged product is a cosmetic product According to an embodiment, the packaged product is a detergent.

[0112] The detergent may be in liquid or powder form, compact or not, for example in the form of detergent tablets, among which dishwasher tablets and laundry detergent tablets can be mentioned, or it may be a liquid detergent, such as liquid laundry detergent.

[0077] Method for manufacturing multi-layered materials

[0113] Multilayer materials can be produced by lamination, coating, sheet paste methods (French: "contre-collage"), coextrusion or extrusion coating methods (French: "extrusion couchage") well known to those skilled in the art.

[0078]

[0114] The present disclosure also provides a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) Coating with a solution S comprising: or a layer of cellulosic material A, a. at least one casein and / or at least one caseinate; B. Water, and At least one plasticizer different from cb) with a layer of material B, optionally with a binder, preferably by carrying out a compounding or lamination process, The present invention relates to a method for producing a multilayer material, characterized in that the method is carried out by any one of the following methods.

[0079]

[0115] According to an embodiment, the production of the multi-layer material is carried out by coating. In this case, the cellulosic material A layer is coated with a solution S. This can be done with coating materials (in French "materiel de couchage") well known to the person skilled in the art. After coating, the coated cellulosic material A can be dried, for example in an oven, to obtain the multi-layer material.

[0080]

[0116] According to another embodiment, the production of the multilayer material is carried out by assembling a layer of cellulosic material A with a layer of material B. In this case, the assembling can be carried out by compounding or lamination.

[0081]

[0117] Lamination can be performed cold or hot. In the case of cold lamination, a binder can be used. In the case of hot lamination, this step can be performed without a binder.

[0082]

[0118] The compounding can be carried out by lamination, coextrusion or extrusion coating steps, with or without a binder.

[0119] If a binder is used, assembly can be performed, for example, by coating one side of one of materials A or B with the binder and then contacting the two materials such that the binder is between them. Assembly can be performed using a calendar. EXAMPLES

[0083]

[0120] In the following examples, two cellulosic materials (paper) were coated with glycerol and sodium caseinate solutions prepared from thermoplastic granules to prepare multi-layer materials according to the present invention. Unless otherwise stated, all percentages in this specification are by weight.

[0084]

[0121] The cellulosic materials used were as follows: - Algro Sol PCC 90g / m2 paper by Sappi, kraft paper coated with kaolin on one side, format 21x35cm, coated on the glossy side, - Terrana 85 g / m2 paper by Gascogne Paper, natural kraft paper rubbed on one side, coated on the rubbed side, format 21 x 35 cm.

[0085]

[0122] The thermoplastic granules used for the coating were prepared by extrusion from sodium caseinate. The extruder used was a Clextral® BC21 co-rotating twin screw extruder with a diameter of 25 mm, a centre distance of 21 mm and a length of 900 mm. The extruder has at least four zones: First Zone for Installation Second Zone for Installation A third zone for degassing, and Fourth Zone: Die.

[0086]

[0123] The rotation speed of the twin screw is between 175 and 320 rpm and the temperatures of the different zones are between 30 and 120°C. The first zone of the extruder is the introduction zone of the caseinate and lecithin powders. The liquid is introduced in the second zone. The extruder further comprises a degassing zone open to atmosphere and a final zone consisting of a cylindrical rod die with a diameter of 4 mm. The screw profile is as follows: 750mm direct pitch screw, 50mm mixing screw, 100mm reverse pitch screw. At the exit of the extruder, the rods are dried and introduced into a granulator which produces granules with a diameter of 2-3 mm. The final composition of the granules is as follows: 63% sodium caseinate, 23.5% glycerol 10% water, 2.3% soy lecithin, and 1.1% Oleic Acid.

[0087] Paper Coating

[0124] The thermoplastic granules are dissolved in water with stirring to obtain solutions of 11%, 18% or 19% dry matter.

[0088]

[0125] The solutions were coated onto the paper using an Elcometer laboratory coating ("couchage" in French) equipment, which uses a translating screw rod to spread and deliver the solution onto the surface of the paper. Two coats were applied to the same side of each paper, giving layer weights of 9 g / m2 or 14 g / m2. The results are shown in Table 1.

[0089]

[0126]

[0090] [Table 1]

[0091]

[0127] The coated paper sheets are then dried in an oven at 55° C. and then in a half moon dryer at 80° C. Afterwards they are placed under a heavy metal plate. Characterization of the resulting coated papers

[0092]

[0128] physical properties

[0129] Basis weight and thickness

[0130] The characterization of the uncoated base paper and the coated papers was carried out under standardized conditions of 23 °C - 50% RH (NF EN 20 187, 1993). Basis weight measurements were carried out according to the method described in standard NF EN ISO 536, 2012 and thickness measurements were carried out according to the method described in standard NF EN ISO 534, 2011. The results obtained are in agreement with the expected values ​​and correspond to the differences in adhesion to the two papers.

[0093]

[0131] Adhesion test FINAT method

[0132] Good adhesion is desired between layer B of material containing sodium caseinate and layer A of paper of cellulosic material.

[0094]

[0133] The adhesion of the coated layer to the paper was tested using the Finat1 method: to be able to carry out the test under good conditions, it is necessary to create an amorce (in French "amorce") on the sample, either manually or with tape, in order to pull the coating away from the substrate and peel off the layer. However, if the adhesion between the coated layer and the paper substrate is too strong, it is not possible to create such an amorce.

[0095]

[0134] The adhesion was then tested using the Finat3 method: according to this method the coated substrate is bonded to a plate using tape. The test specimens thus prepared are made according to the Finat3 method, i.e. by holding the plate / tape / coated paper assembly under a pressure of 6.86 kPa (70 g / cm2) for 20 hours at 23 °C. As with the Finat1 method, no delamination between the coated layer and the paper substrate was observed. In fact, delamination occurred at the level of the tape.

[0096]

[0135] These tests show that the layer attached to the surface adheres very well to the paper substrate, so that the peel force cannot be measured. The adhesion of the coated layer to the different substrates is very good, regardless of the weight of the attached layer (9 g / m2 or 14 g / m2).

[0097]

[0136] Barrier properties

[0137] Grease Barrier: Cobb Index Measurement Method for Oils

[0138] The Cobb index measurement is carried out on a surface of 25 cm2, the duration of which is here taken to be 60 seconds. ISIO4 oil coloured with Sudan Red III is used, which allows the visualization of defects, if any. A method derived from the SCAN-P37 standard is used. By measuring the Cobb index it is possible to determine the amount of oil that a paper or cardboard surface can absorb in a specific time, here 60 seconds. The Cobb index should be as low as possible.

[0098]

[0139] Measurements are performed on five different samples. The average value and standard deviation are then calculated. Measurements are performed under conditions of 23°C / 50% RH after leaving the samples at 23°C / 50% RH for at least 12 hours. The results are shown in Table 2.

[0099]

[0140]

[0100] [Table 2]

[0101]

[0141] These results show that the multi-layer material according to the invention has a much lower Cobb Index than the uncoated paper substrate, reflecting improved grease barrier properties.

[0102]

[0142] Oxygen Barrier: OTR measurement characteristics evaluation at 23℃-50%RH according to ASTM F1927 standard

[0143] Oxygen measurements are performed using a Presens instrument according to ASTM F1927 standard. Measurements are performed at regulated room temperature and humidity levels, i.e. 23°C / 50%RH. Measurements were performed twice on four different samples. The results are shown in Table 3.

[0103]

[0144]

[0104] [Table 3]

[0105]

[0145] These results show that the multi-layer material according to the invention has a much lower oxygen permeability than the uncoated paper substrate, reflecting improved oxygen barrier properties.

[0106]

[0146] Recyclability of the multi-layer material according to the invention

[0147] The recyclability of the multi-layer material according to the invention was determined. The recyclability of packaging materials is assessed within the purposes of Directive 2018 / 852 / EU of 30 May 2018 (amending Directive 94 / 62 / EC).

[0107]

[0148] The recyclability of packaging comes down to fulfilling two criteria so that the packaging can be recovered in the recycled paper industry: - the packaging material must be of cardboard-based construction, containing at least 50% by weight of paper-cardboard material; and - Packaging must be designed with materials or combinations of materials that are compatible with the relevant known recycling techniques available in the industry and must not adversely affect the recycling process.

[0108]

[0149] All multi-layer materials prepared according to the invention contain at least 50% by weight of paper / cardboard material. The first condition is therefore met.

[0150] Recycling tests were then carried out on the multi-layer material prepared according to the invention in order to evaluate the effect of the presence of a layer of material B containing sodium caseinate. The different steps carried out are given below.

[0109]

[0151] Pulping or resuspension (ISO 5263-1* standard)

[0152] The pulping operation consists of individualizing the cellulosic fibers using a laboratory pulper so that the fibrous suspension can be pumped for screening purposes. For testing purposes, especially for resuspension purposes, a 60 g sample was torn into pieces of approximately 3 x 3 cm to fit the size of the laboratory pulper. The prepared material is then resuspended under the following conditions: -Temperature*:40℃ -Concentration: 3% (weight) -Time: 15 minutes -Condition: Neutral

[0153] These conditions are representative of those applied industrially (*Exception: temperature of 40° C. to simulate water temperature in industrial recycling processes).

[0110]

[0154] Observation of fibrous suspension after defibration

[0155] After 15 minutes of defibration, the defibrated material (called the pulp or fibrous suspension) is visually inspected to see two things: - The individualization of the fibers indicates good defibration and therefore a sufficient pulping time, which can be extended by 15 minutes if necessary. -Check the color of the pulping water to see if any packaging material has been discharged (color, ink and / or sheen).

[0111]

[0156] Screening or removal of non-fibrous waste (TAPPI-ANSI T275 sp-18 standard):

[0157] The pulp corresponding to the defibration of the sample to be tested is then collected and further screened in two cascaded Somerville laboratory screening devices, the first equipped with a sieve with 15 / 100 mm slots and the second with a 10 / 100 mm sieve. The accepted pulp passes through the slots of the screener, while the undesirable elements (such as plastic fragments) remain on the surface of the screening sieve. The first screener is able to retain the larger contaminants and the second screener any remaining contaminants.

[0112]

[0158] Appearance Handsheet

[0159] At the outlet of the pulping step and the 10 / 100 mm screening step, laboratory sheets (called hand sheets) are prepared according to the Rapid-Koethen method (standard ISO 5269-2:2004 Pulp - Preparation of laboratory sheets).

[0113]

[0160] The results obtained are shown in Table 4 below.

[0161]

[0114] [Table 4]

[0115]

[0162] These results show that: - Good fiber individualization is achieved during pulping. - Adequate rejection rates are obtained during screening; these rates are acceptable with regard to recyclability. - The handsheet at the exit of the pulper or screen has a fully satisfactory visual appearance.

[0116]

[0163] These results show that the multi-layer material according to the invention meets well the different recyclability criteria for packaging materials for the purposes of Directive 2018 / 852 / EU of 30 May 2018.

[0117]

[0164] The presence of a layer of material B comprising glycerol and sodium caseinate on layer A of cellulosic material does not affect the recyclability of this cellulosic material.

[0118]

[0165] Heat sealability of the multi-layer material according to the invention

[0166] Multi-layer materials were prepared according to the procedure described above. The layer weight was 10 g / m2. Heat sealability tests were performed on a Lako Seal Tester SL10 device from Lako Sool with the following parameters: -Pressure: 0.2N / mm2 -Contact time: 0.5 seconds -Temperature: Between 150~170℃. The dimensions of the heat sealed specimen were 20 mm x 25.4 mm.

[0119]

[0167] After sealing the test specimens, they were packed at 23°C and 50% RH for 24 hours. Afterwards, a peel test was carried out without holding the specimen in the T-shape according to the standard ASTM F88. For each selected sealing condition, three peel tests were carried out. Sample width: 25mm Peel distance: = 20mm, i.e. sealing distance Peel speed: 300mm / min.

[0120]

[0168] The results obtained are shown in Table 4 below.

[0169]

[0121] [Table 5]

[0122]

[0170] These results show that the multi-layer material according to the invention has good weldability. In fact, the fact that there is cohesive failure indicates that the failure occurs within the material and not at the seal. Furthermore, the peel forces of the sealings performed at 150°C, 160°C or 170°C are similar and strong. Thus, the multi-layer material according to the invention has good heat sealability.

Claims

1. i) at least one layer of a cellulosic material A, and ii) at least one layer of a material B, wherein a. at least one casein and / or at least one caseinate, b. water, and c. at least one plasticizer different from b) are included in said at least one layer of material B comprising a multilayer material.

2. The multilayer material according to claim 1, characterized in that material B further comprises gelatin d).

3. Material B polybasic carboxylic acid ester; C3-C33 carboxylic acids, preferably C4-C28 fatty acids, more preferably C6-C28 unsaturated fatty acids; and mixtures thereof is preferably selected from The multilayer material according to claim 1 or 2, characterized in that it also comprises a hydrophobizing agent e).

4. The multilayer material according to claim 1 or 2, characterized in that material B further comprises at least one surfactant f), preferably selected from zwitterionic surfactants with an HLB between 2 and 8.

5. The multilayer material according to claim 1 or 2, characterized in that said plasticizer c) of material B is selected from polyols, glycerol acetate, glycerol propionate, and mixtures thereof, preferably c) is selected from glycerol, sorbitol, and mixtures thereof.

6. The multilayer material according to claim 1 or 2, characterized in that material B contains casein and / or caseinate a) between 10% and 80%, preferably between 20% and 75%, more preferably between 25% and 70%.

7. The multilayer material according to claim 1 or 2, characterized in that said cellulosic material A is selected from paper and cardboard.

8. The multilayer material according to claim 1 or 2, characterized in that said layer of material B is a film layer of material B.

9. Coating the layer of cellulosic material A with a. at least one casein and / or at least one caseinate, b. water, and c. at least one plasticizer different from b) in solution S; or assembling the layer of cellulosic material A and a. at least one casein and / or at least one caseinate, b. water, and c. at least one plasticizer different from b) comprising a layer of material B, optionally using a binder, preferably by means of complexing or laminating. A multilayer material obtained by any of the following.

10. A packaging material comprising the multilayer material according to claim 1 or 2.

11. A product characterized by being packaged in the packaging material according to claim 10.

12. The product according to claim 11, characterized in that it is a food.

13. A method for manufacturing a multilayer material, coating a layer of a cellulosic material A with a solution S containing a. at least one casein and / or at least one caseinate, b. water, and c. at least one plasticizer different from b), or assembling a layer of a cellulosic material A and a layer of a material B containing a. at least one casein and / or at least one caseinate, b. water, and c. at least one plasticizer different from b), optionally using a binder, preferably by performing complexation or lamination. A method characterized by being carried out by any of the above. ​