Method for producing coating material, in particular coating on basis of prolamin material

Abstract

A method for producing a coating material, in particular a coating based on a prolamin material, comprising providing an input material substantially comprising a protein, a lipid and an additive, applying the input material to a substrate, thereby obtaining a coating material having the following properties: a KIT value higher than 11, a WVTR value strictly lower than 55 g / m2 / day, a Cobb 1800 value strictly lower than 15 g / m2, and heat sealing properties.

Description

[0001] This application claims priority to Luxembourg application LU504451 filed on June 7, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to a method for producing a coating material, in particular a coating based on a prolamin material. Background Art

[0003] International patent application WO 2012 / 068118 A1 discloses a composition consisting of only alcohol-soluble protein, surfactant and water, which can provide grease resistance to paper, textiles or other substrates. WO 2012 / 068118 A1 discloses a method for coating a substrate, which includes the step of applying a coating composition, which includes 5 wt% to 15 wt% of alcohol-soluble protein, 5 wt% to 15 wt% of surfactant, 70 wt% to 90 wt% of water further combined with a polysaccharide. The alcohol-soluble protein is zein, the surfactant is sodium dodecyl sulfate (SDS) and the substrate is selected from the group consisting of paper, cardboard, wood, inorganic substrates and textiles.

[0004] SDS cannot be used in food at a concentration exceeding 0.5% by weight. In addition, Annex I to Regulation 10 / 2011 / EU on plastics in contact with food, as amended by Regulation 2020 / 1245 / EU of September 2020, does not include SDS among the authorized substances.

[0005] In addition, the polysaccharide in WO 2012 / 068118 A1 is selected from starch because starch acts as a binder. Starch dissolves in water and adheres to the vitamins and zein of paper. Starch can keep paper and zein together and prevent the coating composition containing zein from being easily rubbed off from the substrate made of paper.

[0006] CN 1 302 550 A discloses an alcohol-soluble corn protein film, which is prepared by extracting alcohol-soluble corn protein from corn gluten in an ethanol solution, concentrating the extract, adding appropriate additives, and directly casting. The alcohol-soluble corn protein film is a film with oxygen-isolating, moisture-proof, and oil-resistant functions, can withstand a high temperature of 200 degrees Celsius, can withstand microwave oven baking, has good printability, is edible, expands when exposed to water, has a good taste, and is an edible functional packaging film that can be used for packaging food, medicines, and chemicals.

[0007] US2004 / 056388 A1 discloses a film E3 which has better properties than film B2: (iii) increased resistance to splashing water, (iv) reduced water vapor permeability, for example, by about 10%. The film of US2004 / 056388 A1 cannot bend under tension but cracks. Cracks mean that the barrier properties are deteriorated.

[0008] WO 2021 / 249621 discloses a method for producing a waterproof film for corn gluten meal.

[0009] US2 185 119 A discloses mixing 10 parts of zein with 40 parts of furfuryl alcohol. Zein forms a clear, stable solution in furfuryl alcohol under stirring and heating at about 185° to 195°F. These films are very strong and have unusual adhesion properties. With the help of these coating compositions, their film-forming properties can be established to produce films with greater toughness, flexibility, hardness and gloss than films formed by the coating compositions.

[0010] There is a need for a method for producing food contact safe coating materials, especially coatings based on prolamin materials, having improved barrier resistance properties. Summary of the invention

[0011] This problem is solved by the subject matter of claims 1, 4, 11, 14 and 19. Further aspects and preferred embodiments of the invention are defined in the method and use claims and their dependent claims and are derived from the following description, the accompanying examples and in particular the accompanying further patent claims.

[0012] In a first aspect, the present disclosure teaches a method for producing a coating material, in particular a coating based on a prolamin material. The method comprises providing an input material substantially comprising a protein, a lipid and an additive, the protein comprising a prolamin, dissolving the input material in an organic solvent, and depositing the liquid input material on a substrate, thereby obtaining a coating material having at least two of the following properties: a KIT value higher than 11, a WVTR value strictly lower than 55 g / m 2 / day, Cobb 1800 value is strictly below 15g / m 2 and appropriate heat sealing properties.

[0013] In a second aspect, a method for producing a coating material, in particular a coating based on a prolamin material, comprises providing an input material substantially comprising a protein, a lipid and an additive. The method further comprises applying the input material to a substrate, thereby obtaining a coating material having the following properties: a KIT value higher than 11, a WVTR value strictly lower than 55 g / m 2 / day, Cobb 1800 value is strictly below 75g / m2 and appropriate heat sealing properties.

[0014] The term "lipid" refers to compounds that are soluble in organic solvents but insoluble in polar solvents such as water. Lipids include fats and oils, such as triglycerides, phospholipids or waxes.

[0015] The term "fat" refers to a lipid composed of triesters of glycerol and fatty acids, or triglycerides.

[0016] The term "fatty acid" refers to a carboxylic acid having a saturated or unsaturated aliphatic chain.

[0017] The term "coating material" refers to a coating on a substrate. In other words, the coating material includes a coating, such as a film, disposed on a substrate.

[0018] The term "heat sealing properties" can be quantified by the likelihood of the weld opening, but also by the risk of delamination (ie separation) of the coating from the substrate.

[0019] In another aspect, the present disclosure teaches a method for producing a coated material, particularly a coated material having a substrate and a coating based on a prolamin material obtained from a corn gluten source. The method comprises producing an input material in the form of particles, comprising the steps of (i) mixing a prolamin-containing biomass, such as a grain source or a water-insoluble portion of a grain, having prolamin and lipids, with an organic solvent to obtain an insoluble component and a dissolved component, the dissolved component comprising dissolved prolamin with a folded configuration, lipids and other dissolved components, (ii) extracting the dissolved component into a first liquid and extracting the insoluble component into a first solid, such that the dissolved prolamin with a folded configuration accounts for at least 80% in the first solution, (iii) separating the first solid from the first liquid, (iv) recovering the input material from the first liquid as a powder or slurry by removing the organic solvent, and optionally the steps of extruding the recovered input material to obtain the input material in the form of particles, extruding the input material with a die of an extruder, and applying the extruded input material to a substrate to obtain a coated material.

[0020] In another aspect, a method for producing a coated material, in particular a coated material having a substrate and a coating made of particles obtained from a prolamin source, the particles being thermoplastic and preferably having the ability to be extruded in an extrusion die. The method comprises extruding the particles with a die, depositing the extruded material on a substrate, thereby obtaining a coated material.

[0021] In another aspect, the present disclosure teaches a coated material comprising a substrate and a coating made of particles obtained from a prolamin source. The coated material has at least two of the following properties: a KIT value higher than 11, a WVTR value strictly lower than 55 g / m2 / day, Cobb 1800 value is strictly below 75g / m 2 and appropriate heat sealing properties.

[0022] According to the first and second aspects, the coated material has improved water resistance. The coated material also has improved water vapor resistance and grease resistance. The coated material is stable and has suitable heat sealing properties. The method of the present invention does not require the addition of crosslinking agents or polysaccharides to the input material.

[0023] On the other hand, the input material mainly comprises, by dry weight, more than 40 wt% protein, more preferably more than 50 wt% protein, between 1 wt% and 40 wt% lipids, between 5 wt% and 40 wt% additives, preferably the additives are selected from one of processing additives, hydrophobic additives or a combination thereof, more preferably the additives are selected from between 5 wt% and 20 wt% processing additives, between 5 wt% and 20 wt% hydrophobic additives or a combination thereof.

[0024] The terms “processing additives” and “hydrophobic additives” refer to two different classes of additives used in the formulation of coating materials. Additives used in the formulation of coating materials are known, for example, in “Protein-based films: Advances in the development of biomaterials suitable for food packaging,” Sergio J. Calva Estrad et al., Food Eng Rev (2019) 11:78–92, https: / / doi.org / 10.1007 / s12393-019-09189-w.

[0025] Processing additives are substances added to a coating formulation during the manufacturing process to improve the properties of a resin or binder. Processing additives are intended to improve the flow and leveling of the final coating and help reduce the occurrence of defects in the coating such as fish eyes, orange peel and benacells. Examples of processing additives include surfactants and / or small linear alcohols.

[0026] Hydrophobic additives refer to substances added to coating formulations to impart water-repellent properties to the final coating. Hydrophobic additives are intended to reduce water absorption and improve moisture resistance, thereby enhancing the durability and protection of the final coating, especially in environments exposed to water or humidity. Examples of hydrophobic additives include lipids. In one aspect, the prolamin-based material includes a prolamin having the structure and distribution of a naturally occurring prolamin and a lipid having the structure and distribution of a naturally occurring lipid.

[0027] The term "naturally occurring prolamin structure and distribution" may refer to the naturally occurring prolamin structure and distribution in a prolamin-based material. The term "lipids having naturally occurring lipid structure and distribution" may refer to the naturally occurring lipid structure and distribution in lipids of a prolamin-based material.

[0028] In one aspect, the substrate is a vitamin-based substrate or a cardboard-based substrate.

[0029] In another aspect, the method further comprises dissolving the input material in an organic solvent prior to applying to the substrate, thereby obtaining a coating material, characterized in that the organic solvent comprises at least 60 wt % ethanol. The organic solvent is capable of dissolving the prolamin in the input material and rapidly drying the coating material.

[0030] In one aspect, the extrusion is carried out at a temperature of at least 70°C, preferably between 80°C and 140°C, more preferably at 100°C.

[0031] In one aspect, the extruder is a single screw extruder, preferably a single screw having a screw speed of at least 20 rpm, more preferably between 30 rpm and 130 rpm and more preferably 90 rpm.

[0032] In one aspect, the extruder is a twin screw extruder, preferably a twin screw extruder having a screw speed of at least 20 rpm, more preferably between 30 rpm and 130 rpm and more preferably 90 rpm.

[0033] In one aspect, the method comprises depositing the extruded input material on a substrate, followed by cooling the deposited material, preferably at a temperature between 60° C. and 110° C., more preferably between 70° C. and 100° C., and more preferably at 85° C. Cooling can improve the adhesion characteristics of the input material as a coating on the substrate.

[0034] In another aspect, the present disclosure teaches the use of the obtained coated material. The coated material is used in paper bags, shipping bags, frozen or non-frozen food containers. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A process flow diagram of a method for producing a coated material, in particular a coated material with a substrate and a coating based on a prolamin material, according to one embodiment of the present invention is illustrated.

[0036] Figure 2 A process flow chart of a method for producing a coating material, in particular a coating material having a substrate and a coating based on a prolamin material, according to another embodiment of the present invention is illustrated.

[0037] Figure 3A comparison of the coated material and the zein-based material coated on a substrate is shown. DETAILED DESCRIPTION

[0038] Input Materials

[0039] A method for producing a coating material, in particular a coating based on a prolamin material, the method comprising providing an input material, the input material essentially comprising a protein, a lipid and an additive, the protein comprising a prolamin.

[0040] In one embodiment, the input material comprises at least 700 mg / g protein of dry matter, including at most 250 mg / g fat.

[0041] In another embodiment, the input material comprises between 750 mg / g dry matter and 950 mg / g dry matter protein.

[0042] In another embodiment, the input material comprises 800 mg / g dry matter protein.

[0043] The alcohol-soluble protein is, for example, selected from zein, hordein, gliadin or kafirin, preferably zein.

[0044] Prolamin-based materials include prolamins having the structure and distribution of naturally occurring prolamins and lipids having the structure and distribution of naturally occurring lipids.

[0045] In one embodiment, the input material comprises at least 15 mg / g dry matter fat, of which at least 18 g saturated fatty acids per 100 g fat.

[0046] In another embodiment, the input material comprises between 15 mg / g dry matter and 250 mg / g dry matter fat, with between 18 g and 25 g saturated fatty acids per 100 g fat.

[0047] In one embodiment, the input material comprises greater than 50 wt% protein, between 1 wt% and 40 wt% lipids and between 5 wt% and 40 wt% additives.

[0048] In another embodiment, the input material comprises greater than 60 wt% protein.In another embodiment, the input material comprises at most 35 wt% additives.

[0049] In one embodiment, the additive is selected from one of a processing additive, a hydrophobic additive, or a combination thereof. In one embodiment, the additive includes between 5 wt % and 20 wt % of a processing additive, between 5 wt % and 20 wt % of a hydrophobic additive, or a combination thereof.

[0050] In one aspect, the processing additive is selected from one of a surfactant and / or a linear alcohol, such as a short chain linear alcohol.

[0051] In one aspect, the hydrophobic additive is selected from lipids.

[0052] In another embodiment, the input material contains between 5 wt % and 10 wt % of a processing additive and between 5 wt % and 10 wt % of a hydrophobic additive such that the coating material is flexible.

[0053] Prior to providing the input material, a suitable input material having a "defined" protein and a "defined" lipid profile is produced.

[0054] In one embodiment, the input material is in powder or granular form.

[0055] In one embodiment, the input material is produced in pelletized form prior to being provided.

[0056] Producing the input material in pellet form involves the following steps:

[0057] (i) mixing a prolamin-containing biomass, such as a cereal source or a water-insoluble portion of a cereal, having prolamin and lipids, with an organic solvent to obtain an insoluble fraction and a dissolved fraction, the dissolved fraction comprising dissolved prolamin in a folded configuration, lipids and other dissolved components;

[0058] (ii) extracting dissolved components into a first liquid and extracting insoluble components into a first solid such that the dissolved prolamin in a folded configuration accounts for at least 80% of the first solution;

[0059] (iii) separating the first solid from the first liquid;

[0060] (iv) recovering the input material as a powder or slurry from the first liquid by removing the organic solvent.

[0061] The recycled input material is a thermoplastic material.

[0062] Extract the dielectric constant ε by r (at 25°C) and kept between 30 and 42. One of the purposes of this step is to keep the conformation (i.e., configuration) of the prolamin in the input material consistent with the conformation of the prolamin after the input material is deposited on the substrate to obtain the coating. The specific conformation of the prolamin is related to the folding of the prolamin.

[0063] The unique feature of the recycled input material, being thermoplastic, appears to be related both to the folding of the prolamins and lipids and to the apparent interactions between these components. The structural composition of the prolamins remained unchanged.

[0064] On the other hand, the ratios between lipids / fatty acids in the input material remain constant throughout the production of the input material. The ratios between lipids / fatty acids are maintained at the following levels, given in the following order, in weight % of total lipids: free fatty acids / monoglycerides / diglycerides / triglycerides: 91 / 3 / 5 / 1 in the first liquid phase and 95 / 2 / 3 / 0 in the second liquid phase. The ratios in corn gluten meal are 84 / 3 / 8 / 4 and in commercial corn gluten meal are 54 / 9 / 26 / 11. This is advantageous to have a high free fatty acid content, which increases the flexibility of the film and enhances the thermoplastic properties by producing a higher MVR. It should be noted that these ratios depend on the initial biomass and therefore deviations may occur.

[0065] The lipid / fatty acid ratio is maintained by adjusting the dielectric constant to overcome the variation in lipid profile in gluten-derived materials, such as prolamin-containing biomass.

[0066] Throughout the process, the lipid content is preferably kept above 4% by weight, preferably between 4% and 23%, relative to the dry matter.

[0067] In one embodiment, the lipid content is less than 4% by weight relative to dry matter.

[0068] Extraction is performed within a time less than time te, where te (expressed in min) is defined as: ke1*T (expressed in °C)+ke2*ε r (at 25°C)+ke3*p(bar absolute), wherein te is expressed in minutes, ke1 is a constant in the range between 0.04 and 1.00, preferably between 0.05 and 0.9, more preferably between 0.1 and 0.6, ke2 is a constant in the range between 0.08 and 2.00, preferably between 0.1 and 1.5, more preferably between 0.4 and 0.9, and ke3 is a constant in the range between 1.70 and 60.00, preferably between 5 and 50, more preferably between 15 and 35.

[0069] The recovery is carried out under the following conditions: keep the temperature of the prolamin below 80°C, preferably below 75°C, and most preferably below 70°C; keep the dielectric constant ε r (at 25°C) between 30 and 42, keeping the pressure level below 2 bar, recovering for a time less than the recovery time t (expressed in min), where the recovery time t is defined as kr1*T (expressed in °C) + kr2*ε r (at 25°C) + kr3*p(bar absolute), where kr1 is in the range between 0.0004 and 12.0000, kr2 ​​is in the range between 0.0008 and 7.0000, and kr3 is in the range between 0.0167 and 80000.0000.

[0070] It should be noted that kr1, kr2 ​​and kr3 are constants. kr1 is between 0.0004 and 12, preferably between 1 and 10, more preferably between 2 and 5, kr2 ​​is between 0.0008 and 7, preferably between 1 and 6, more preferably between 2 and 5, and kr3 is between 0.0167 and 80000, preferably between 1 and 70000, more preferably between 10000 and 60000.

[0071] It is important to note that these parameters were obtained through intensive research and are an obvious motivated choice and cannot be assumed to have been applied before, even though in some prior art documents it is claimed that products made from commercially available zein exhibit thermoplastic characteristics. In fact, there is no evidence in the prior art that products made from commercially available zein can exhibit thermoplastic properties, at least not suitable for any industrial application. This can also be seen from the comparative examples discussed further below.

[0072] The recovery time t depends largely on the drying / recovery technique used, for example when a standard oven is used the recovery time t will be in the range between 30 minutes and 15 hours.

[0073] First embodiment

[0074] like Figure 1 As shown, an input material substantially comprising protein, lipid and additives is provided, wherein the protein comprises prolamin, and in one aspect, the input material is subsequently dissolved with an organic solvent to obtain a liquid input material, ie, a coating solution.

[0075] In one embodiment, the organic solvent comprises ethanol and water. The organic solvent, for example, comprises at least 60 wt. % ethanol, preferably between 70 wt. % and 85 wt. % ethanol, more preferably 80 wt. % ethanol.

[0076] The coating solution is, for example, a dispersion. The dispersion comprises, for example, 50% by weight of dissolved particles, such as proteins such as prolamin, lipids and other dissolved components, such as additives.

[0077] In another embodiment, the dissolution is carried out in a high shear mixer to avoid the presence of insoluble particles in the coating solution. Insoluble particles in the coating solution lead to a coating material with an uneven coating. Insoluble particles are breaking points in the coating material. Insoluble particles lead to ruptures in the coating material, i.e. bending of the coating material. For example, a coating solution with substantially no insoluble particles, i.e. a clear coating solution, can be obtained by filtering the coating solution with a 100 μm filter cloth.

[0078] In one non-limiting embodiment, at least one additive is added to the coating solution.

[0079] In another non-limiting embodiment, an additive mixture is added to the coating solution. The additive mixture, for example, includes three additives selected from two processing additives and one hydrophobic additive.

[0080] In one embodiment, two processing additives are selected from surfactants and / or linear alcohols, such as short chain linear alcohols, and one hydrophobic additive is a lipid.

[0081] The concentration of the sum of the additives in the coating solution is, for example, at least 10% by weight, preferably between 20% and 40% by weight.

[0082] In one embodiment, the method comprises the step of grinding the input material prior to dissolving the input material with the organic solvent to reduce the particle size of the input material to at most 1000 microns, preferably at most 500 microns.

[0083] After dissolution, the liquid input material, ie the coating solution, is deposited on the substrate, thereby obtaining the coating material.

[0084] The deposition of the coating solution can be carried out by a suitable means, such as an applicator with a coating knife, and in one embodiment, the deposition of the coating solution is carried out with a vacuum assisted film coating applicator. The gap between the vacuum assisted film coating applicator and the coating solution can be selected according to the coating application. The gap between the vacuum assisted film coating applicator and the coating solution can be selected between 10 microns and 100 microns, more preferably between 20 microns and 80 microns, and more preferably between 30 microns and 50 microns.

[0085] The use of a vacuum assisted film coating applicator enables the coating solution to be firmly adsorbed on the lower layer of the substrate, i.e., the surface of the substrate to be coated, such as the surface of a cardboard. Firm adsorption enables the coating solution to not slide off the substrate. The coating solution on the substrate has a thickness of at least 5 microns, between 5 microns and 100 microns, and preferably between 10 microns and 40 microns.

[0086] The substrate is, for example, a film, a vitamin-based substrate, a paper-based substrate, a cardboard-based substrate or a cardboard.

[0087] In one embodiment, the method includes drying the liquid input material deposited on the substrate, preferably at room temperature. Drying results in evaporation of the organic solvent from the coating material.

[0088] Due to dissolution in an organic solvent, the process advantageously does not require heating.

[0089] In one embodiment, heat may be applied to further accelerate the drying process.

[0090] The method also does not require the additional step of applying high pressure, ie, pressure greater than atmospheric pressure. High pressure increases the time to dry the coated material.

[0091] Second embodiment

[0092] On the other hand, Figure 2 As shown, an input material substantially comprising protein, lipid and additives is provided, and the input material is subsequently extruded in an extruder.

[0093] The extruder is, for example, a single screw extruder or a twin screw extruder. In another embodiment, the extruder is a twin screw extruder.

[0094] The temperature in the extruder is at least 70°C, at least 85°C, from 95°C to 125°C, between 80°C and 140°C, or 105°C.

[0095] The extrusion is carried out at a screw speed of at least 20 rpm, at least 30 rpm, between 40 rpm and 200 rpm, between 30 rpm and 130 rpm, between 70 rpm and 120 rpm, for example 90 rpm.

[0096] The extrusion material is extruded through the opening of an extrusion die made of a round hole nozzle, preferably the round hole nozzle has a diameter of at least 1.3 mm, preferably 2.7 mm. In one embodiment, the nozzle is a flat die with dimensions of 200 mm x 0.6 mm.

[0097] In another embodiment, the extruded material is extruded through an opening of an extrusion die made of a flat nozzle, preferably a flat nozzle having a gap of at least 0.1 mm. Extrusion through a flat nozzle results in obtaining the extruded material in the form of a stretched molten film.

[0098] The extruded material is deposited on the substrate, in particular, the extruded material is attached to one side of the substrate using a pressure roller. The extruded material is elongated on the substrate and then deposited on the substrate.

[0099] The substrate is, for example, located below the opening of an extrusion die, preferably with a continuous displacement speed.

[0100] In one embodiment, the substrate has a higher velocity than the extruded material deposited on the substrate.

[0101] In one embodiment, the substrate has a smooth surface.

[0102] In one embodiment, the extrusion is carried out at a pressure of at least 5 bar, between 15 bar and 90 bar, on an extrusion die of an extruder.

[0103] The method further includes cooling the deposited material by utilizing a cooling roller.

[0104] In one embodiment, cooling is performed at a temperature between 60°C and 110°C, between 70°C and 100°C, at 85°C.

[0105] In one embodiment, the chill roll is heated to a temperature above 50°C to achieve adhesion between the input material and the substrate, more preferably between 60°C and 90°C.

[0106] The substrate is, for example, a film, a vitamin-based substrate, a paper-based substrate, a cardboard-based substrate or a cardboard.

[0107] The coated material has the characteristics of an optically clear surface and a uniform coating thickness on the substrate.

[0108] Uniform thickness means the coating thickness tolerance is 2g / m 2 Up to 5g / m 2 .

[0109] Optically clear means that the surface of the coated material is translucent to the naked eye.

[0110] The method can obtain a uniform coating material.

[0111] Compared with the input material in powder form, the uniformity of the coating material is significantly better when the input material is in granular form. The reason is that extrusion and / or granulation makes the input material uniform throughout the extrusion granulation process. Extrusion makes it easier for the input material to melt into a uniform mass, and the uniform mass is coated on the substrate resulting in a uniform coating material. Without extrusion and / or granulation, extrusion of the input material for use as a paper coating, for example, may result in a coating material containing unmelted particles and a coating material with an uneven coating.

[0112] Third embodiment

[0113] On the other hand, the method for producing coating material comprises producing input material in the form of particles. The production of input material comprises first mixing the water-insoluble part of the biomass containing alcohol-soluble protein, such as a cereal source or a cereal, with alcohol-soluble protein and lipids, with an organic solvent to obtain an insoluble component and a dissolved component, the dissolved component comprising alcohol-soluble protein, lipids and other dissolved components with a folded configuration. The method also comprises extracting the dissolved component into a first liquid and extracting the insoluble component into a first solid, so that the alcohol-soluble protein with a folded configuration accounts for at least 80% in the first solution. After extracting the dissolved component into the first liquid and extracting the insoluble component into the first solid, the first solid is separated from the first liquid. Then, the input material is recovered from the first liquid as a powder or slurry by removing the organic solvent. In some aspects, the powder or slurry can be extruded to form particles. The method also comprises coating the recovered input material on a substrate, thereby obtaining a coating material.

[0114] In one aspect, coating includes extruding the recycled input material and then outputting the extruded material on a substrate through a die of an extruder. In one aspect, the extruded material is attached to one side of the substrate through a pressure roller. The extruded material is stretched on the substrate and then deposited on the substrate to obtain a coated material.

[0115] In another aspect, the pressure roller is cooled to adhere the extruded material to the substrate.

[0116] In another aspect, the coating is performed by dissolving the recovered input material in an organic solvent, such as an ethanol-water based solvent. After dissolution, the dissolved recovered input is deposited on a substrate to obtain a coated material. The dissolved recovered input is deposited, i.e., coated, for example, using an applicator with a coating knife, a vacuum assisted film coating applicator or other suitable applicator, and / or poured on a substrate to obtain a coated material.

[0117] Coating material

[0118] The coating materials obtained from the first, second and third embodiments surprisingly have improved water barrier resistance, ie water repellency, improved water vapor resistance, improved grease resistance, ie oil repellency, and improved heat sealing properties.

[0119] Sealability is primarily intended to identify the quality of the thermal weld between two sheets of coating material, but it can also determine the quality of adhesion between a layer and a substrate in contact with each other, since the weld itself or the bond between the layer and the substrate may be compromised if a tearing attempt is made.

[0120] The thickness of the coating on the substrate is, for example, between 10 microns and 25 microns. In another embodiment, the thickness of the coating is 4 g / m 2 and 40g / m 2 In another embodiment, the coating thickness is between 2 g / m 2 and 5g / m 2 between.

[0121] In a first embodiment, the coating material has a KIT value higher than 11. The KIT test is performed according to TAPPI test method T559. The coating material also has a water vapor transmission rate (WVTR) value strictly lower than 55 g / m 2 / day. The coated material has a Cobb 1800 value strictly below 15g / m 2 The coating material has suitable heat sealing properties.

[0122] In a first embodiment, the liquid input material maintains a specific conformation induced by the substrate, for example during the steps of the method, and in particular the specific conformation of the input material is substantially the same after the liquid input material is deposited on the substrate and during drying of the liquid input material deposited on the substrate. The specific conformation of the alcohol-soluble protein does not change during the process.

[0123] In a second embodiment, the coating material has a KIT value higher than 11. The KIT test is performed according to TAPPI test method T559. The coating material also has a water vapor transmission rate (WVTR) value strictly lower than 55 g / m 2 / day. The coated material has a Cobb 1800 value strictly below 75g / m 2 . The coating material has heat sealing properties.

[0124] In a second embodiment, the coating has the same specific conformation induced by the substrate, for example, after the extruded input material is deposited on the substrate and after the deposited input material cools. The specific conformation of the prolamin does not change during the process, for example, the folded conformation of the prolamin remains the same.

[0125] The coating material comprises a prolamin having a naturally occurring prolamin structure and distribution. The coating material comprises a lipid having a naturally occurring lipid structure and distribution.

[0126] The coated material can be used for a variety of purposes. For example, the coated material is used for frozen or non-frozen food packaging, paper bags or shipping bags.

[0127] The present invention is explained in more detail below by means of selected examples.

[0128] The heat sealing properties are measured by qualitatively analyzing the likelihood of the weld opening and at the same time the risk of the coating delaminating, i.e. separating, from the substrate. If the coating delaminates easily from the substrate, i.e. the coating can be separated from the substrate by hand, the coating material does not have suitable heat sealing properties.

[0129] The heat sealing properties are quantified using a number from 1 to 4. The heat sealing properties are quantified by delamination, i.e. separation of the substrate from the coating, after heat sealing at 150°C, 3 bar, and 0.5 seconds. The quantification value is 1 for separation of the coating from the substrate. The quantification value is 2 for separation of the coating from the substrate without peeling the coating from the substrate. The quantification value is 3 for fracture of the coating during separation and 4 for tearing of the fibers of the coating. Suitable heat sealing properties are between 3 and 4, indicating that the coating material can be processed using well-known heat welding equipment, such as food packaging for take-away restaurants, etc. Therefore, it can be considered that suitable heat sealing properties are well known to those skilled in the art, and reference can be made to the standards of the food packaging industry in this regard.

[0130] Input Materials

[0131] Different input material compositions were further tested to form coating materials.

[0132] Example 1 - Input Material 1:

[0133] Corn gluten meal is obtained from a starch production plant. Then, the corn gluten meal is mixed with an ethanol mixture having a dielectric constant of 35. The mixture is heated to 50°C and stirred at 50°C for two hours. Then, without cooling, the solids are removed by centrifugation at 5000xg for 5 minutes. The first supernatant recovered is cooled to -18°C and placed at -18°C for four hours without changing the dielectric constant. The precipitated solids formed are removed by centrifugation at 5000xg for 5 minutes at 4°C. The second supernatant recovered is dried at room temperature, then ground into a fine powder and sieved to less than 0.5mm. Then, the powder is mixed with 20% by weight of glycerol and then extruded into particles at 100°C. The particles, i.e., input material 1, show good thermoplasticity with a melt volume rate of 50ccm / 10min (5kg).

[0134] Example 2 - Input Material 2:

[0135] The method of Example 1, wherein the second liquid phase is membrane filtered at 4 kDa and 7 bar at room temperature until a viscous liquid is formed as the first residue. The permeate is filtered through a 200 Da filter membrane at room temperature until a viscous liquid is formed as the second residue. The first residue is combined with the second residue and mixed with 20% by weight of glycerol, then dried at room temperature, ground into a powder and sieved to less than 2 mm, and then extruded into pellets at 140°C. The pellets, i.e., input material 2, show good thermoplasticity, with a melt volume rate of 78 ccm / 10min (5 kg) at 20°C.

[0136] Example 3 - Input Material 3:

[0137] The process of Example 1, wherein the dielectric constant of the solvent during extraction was changed to 38, resulted in the same product quality.

[0138] Example 4 - Input Materials 4:

[0139] The method of Example 1, in which the dielectric constant was changed to 50 during extraction, wherein the obtained product, ie, input material 4, did not show thermoplasticity and could not be extruded.

[0140] Examples 5, 6 and 7 were produced using different starting materials to understand whether the produced input materials could be further processed to obtain coated materials.

[0141] Example 5 - Input Materials 5:

[0142] Commercially available zein + 15% (w / w) additive (Comparative Example)

[0143] The input material of Example 5 showed a large swelling and hardening behavior. Remelting and recycling were not possible with commercial zein as input material, indicating that commercial zein is not suitable as an input material for producing coating materials.

[0144] Example 6 - Input Material 6

[0145] Thermoplastic material X + 15% (w / w) additive (illustrative example)

[0146] According to the invention, the thermoplastic material X in the form of granules is produced from biomass and has a protein content of 74% to 78%.

[0147] Thermoplastic material X was easily extruded and a series of extrudate segments had uniform lengths. This demonstrated that a melting process occurred during the measurement, and therefore the method was able to obtain a thermoplastic material. The resulting thermoplastic material X also showed no signs of decomposition, indicating that the material produced in Example 6 was able to be used as an input material for producing a coating material.

[0148] Example 7 - Input Materials 7

[0149] Thermoplastic material Y + 15% (w / w) additive (illustrative example)

[0150] Material Y is made from pretreated biomass containing alcohol-soluble proteins and lipids and has a protein content of 78% to 95%. Material Y is easy to extrude and a series of extrudate segments of uniform length can be obtained. This proves that a melting process occurs during the measurement, so the method is able to obtain a thermoplastic material. The material produced also shows no signs of decomposition, indicating that the material produced in Example 12 can be re-melted and recycled. The additives added in Example 7 can be regarded as plasticizers or lubricants in the method.

[0151] The results indicate that the material produced in Example 7 is suitable for use as an input material for producing a coating material.

[0152] The inventors found that no matter how the die diameter of the extruder is, the input material produced by zein cannot be extruded because the input material produced by zein is stuck in the extruder in advance. The input material produced by zein cannot even be transported to the end of the die of the extruder, so the coating material cannot be produced.

[0153] Coating material

[0154] Example 8 - Coating Material 8

[0155] Example 1 is an illustrative example of the first embodiment.

[0156] The input material consisting of protein and lipid is dried and dissolved with an organic solvent to obtain a coating solution. An additive having a solubility of 40 wt % is added to the coating solution. The input material is in the form of particles.

[0157] The coating solution was dissolved by mixing in a standard Ultra-Turrax apparatus to minimize insoluble particles. A clear coating solution was obtained after filtering through a 100 micron filter cloth filter.

[0158] The coating solution was applied to a substrate made of paper using a vacuum assisted film coating applicator. The coating weight was 25 g / m 2 Up to 30g / m 2 , obtaining coating materials with smooth surface, glossy surface and high reproducibility.

[0159] The results showed that the coated material was very soft, so the coating was completely dry (less than 5% residual moisture) and bending in different directions did not result in cracking or breaking.

[0160] The coated material showed considerable performance, with a moisture vapor transmission rate (WVTR) of 49.5 g / m at 85% relative humidity after 4 days. 2 / day and Cobb 1800 value is 22g / m 2 .

[0161] The separation of the coating material from the substrate was quantified as 4, so the coating material had good sealability.

[0162] Example 9 - Coating Material 9

[0163] Example 9 is another illustrative example of the first embodiment. The input material is mainly made of protein and 30% by weight of additives and is dissolved with an organic solvent consisting of ethanol. The input material is in powder form.

[0164] The coating solution was dissolved by mixing it in a SpeedMixer at 3500 rpm for 10 minutes. Insoluble particles were removed through a filter with a mesh size of 150 μm.

[0165] The coating solution was applied to a substrate made of paper using a vacuum assisted film coating applicator. The coating was 60 g / m 2 The results showed that the coated material was smooth, glossy and soft.

[0166] The results showed that after three days, the WVTR was 39 g / m 2 / day and Cobb 1800 value is 2g / m 2 .

[0167] The separation of the coating material from the substrate is quantified as 4, so the coating material is sealable.

[0168] Example 10 - Coating Material 10

[0169] Example 10 is a comparative example.

[0170] An input material made mainly of zein and 30 wt% of additives was dissolved with an organic solvent made of ethanol. The input material was in the form of powder.

[0171] The coating solution was dissolved by mixing it in a SpeedMixer at 3500 rpm for 10 minutes. Insoluble particles were removed through a filter with a mesh size of 150 μm.

[0172] The coating solution was applied to a substrate made of paper using a vacuum assisted film coating applicator. The coating was 60 g / m 2 .

[0173] Measuring water resistance properties.

[0174] The results showed that after three days, the WVTR was 41g / m 2 / day and Cobb 1800 value is 20g / m 2 .

[0175] The resulting product cannot be heat-sealed properly. There are obvious cracks and no uniform sealing is achieved.

[0176] Example 11 - Coating Material 11

[0177] Example 11 is an illustrative example of the second embodiment.

[0178] An input material made mainly of protein and 25% of additives was applied. The input material was in the form of granules.

[0179] The pellets were used with the paper in an extrusion process, at a speed of 80 rpm and applied between 90° C. and 125° C. The chill roll for coating attachment was adjusted to 65° C.

[0180] The results show that the coating material is uniform. The coating weight is 25g / m 2 Up to 30g / m 2 .

[0181] The results showed that WVTR was 143g / m 2 / day (five days, 50% relative humidity) and Cobb 1800 value is 48 g / m 2 .

[0182] The separation of the coating material from the substrate is quantified as 4, so the coating material is sealable.

[0183] Example 12 - Coating Material 12

[0184] Example 12 is a comparative example.

[0185] The input material made of protein and fatty acids is extruded in a single screw extruder at a temperature between 85° C. and 125° C. The input material is in powder form.

[0186] The results showed that the coated material showed an uneven coating. Therefore, the barrier properties of the coated material were not determined.

[0187] Example 13 - Coating Material 13

[0188] Example 13 is an illustrative example of the second embodiment.

[0189] An input material made mainly of protein and 30% of additives was applied. The input material was in the form of granules.

[0190] The pellets were used in a coextrusion process with the paper, applied at a speed of 90 rpm and between 90°C and 125°C using a 200 mm x 0.6 mm flat die. The chill roll for coating attachment was adjusted to 100°C.

[0191] The results show that the coating material is uniform. The coating weight is 60g / m 2 .

[0192] The results showed that WVTR was 51g / m 2 / day (four days, 50% relative humidity) and Cobb 1800 value is 48 g / m 2 .

[0193] The separation of the coating material from the substrate is quantified as 4, so the coating material is sealable.

[0194] Figure 3 The surface of the coated material made of commercially available zein is shown as well as Figure 3 The top and bottom surfaces of the coated material according to the present invention. Figure 3 It is shown that the coating material made of commercially available zein is broken by bending, while the coating material according to the present invention is not broken by bending.

Claims

1. A method for producing a coated material, in particular a coated material having a substrate and a coating based on a prolamin material, the method comprising: providing an input material substantially comprising protein, lipid, and additives, wherein the protein comprises prolamin; dissolving the input material in an organic solvent; as well as The liquid input material is deposited on a substrate, thereby obtaining the coating material having at least two of the following properties: - KIT value higher than 11; -WVTR value is strictly lower than 55g / m 2 / sky; -Cobb 1800 value strictly below 15g / m 2 ;as well as -Suitable heat sealing properties.

2. The method according to claim 1, in, The organic solvent comprises at least 65 wt% ethanol, preferably between 70 wt% and 85 wt% ethanol, more preferably 80 wt% ethanol.

3. The method according to claim 1 or 2, The method further comprises drying the liquid input material deposited on the substrate after deposition, preferably at room temperature.

4. A method for producing a coated material, in particular a coated material having a substrate and a coating based on a prolamin material, the method comprising: providing an input material substantially comprising protein, lipid, and additives, wherein the protein comprises prolamin; extruding the input material; The extruded input material is deposited on a substrate to obtain the coated material having at least two of the following properties: - KIT value higher than 11; -WVTR value is strictly lower than 55g / m 2 / sky; -Cobb 1800 value strictly below 75g / m 2 ;as well as -Suitable heat sealing properties.

5. The method according to claim 4, in, The extrusion is carried out at a temperature of at least 70°C, preferably between 80°C and 140°C, more preferably at 115°C.

6. The method according to claim 4 or 5, in, The extruded material is extruded through the opening of an extrusion die made of a flat nozzle, preferably with a gap of at least 0.1 mm, and more preferably formed into a film / layer with a subsequent pair of rollers.

7. The method according to any one of claims 4 to 6, in, The depositing comprises depositing the extruded input material onto the substrate below the opening of the extrusion die, preferably with a continuous displacement speed of the substrate.

8. The method according to any one of claims 4 to 7, in, depositing the extruded input material on the substrate, followed by cooling the deposited material, Preferably the cooling is carried out at a temperature between 60°C and 110°C, more preferably between 70°C and 100°C, more preferably at 85°C.

9. The method according to any one of claims 4 to 8, in, The extruding of the input material and / or the depositing of the extruded input material on the substrate may include one of applying heat, pressure, or a combination thereof to maintain the coating on the substrate.

10. The method according to any one of the preceding claims, in, The input materials include: - more than 40% by weight of protein, more preferably more than 50% by weight of protein; - between 1% and 40% by weight of lipids; - between 5 wt% and 40 wt% of additives, preferably the additives are selected from one of processing additives, hydrophobic additives or a combination thereof, more preferably the additives are selected from between 5 wt% and 20 wt% of processing additives, between 5 wt% and 20 wt% of hydrophobic additives or a combination thereof.

11. A method for producing a coated material, particularly a coated material having a substrate and a coating having a prolamin-based material obtained from a corn gluten source, the method comprising: Producing the input material in pellet form comprises the following steps: (i) mixing a prolamin-containing biomass, such as a grain source or a water-insoluble portion of a grain, having prolamin and lipids with an organic solvent to obtain an insoluble component and a dissolved component, the dissolved component comprising dissolved prolamin with a folded configuration, lipids and other dissolved components; (ii) extracting the dissolved components into a first liquid and extracting the insoluble components into a first solid such that the dissolved prolamin in the folded configuration accounts for at least 80% of the first solution; (iii) separating the first solid from the first liquid; (iv) recovering the input material as a powder or slurry from the first liquid by removing the organic solvent; applying the recycled input material to the substrate to obtain the coating material; And optionally, before applying the recycled input material to the substrate, the steps of: extruding the recycled input material to obtain the input material in the form of pellets, The input material is extruded through the die of the extruder, and then The extruded recycled input material is applied to the substrate.

12. The method according to claim 11, in, Extraction is performed within a time less than time te, where te (expressed in min) is defined as: ke1*T(expressed in °C)+ke2*ε r (at 25°C) + ke3*p (absolute value of bar), where te is expressed in minutes; ke1 is a constant in the range between 0.04 and 1.00; ke2 is a constant in the range between 0.08 and 2.00; and ke3 is a constant in the range between 1.70 and 60.

00.

13. The method according to claim 11, in, The recovery is carried out under the following conditions: - maintaining the temperature of the prolamin below 80°C, preferably below 75°C, most preferably below 70°C; - Maintain the dielectric constant ε r (at 25°C) between 30 and 42; - Maintain pressure level below 2 bar; - The recovery is performed at a time less than the recovery time t (expressed in min), the recovery time t being defined as kr1*T (expressed in °C)+kr2*ε r (at 25°C) + kr3*p (bar absolute value), in, kr1 is in the range between 0.0004 and 12.0000; kr2 is in the range between 0.0008 and 7.0000; and KR3 is in the range between 0.0167 and 80000.0000.

14. A method for producing a coated material, in particular a coated material having a substrate and a coating made of particles obtained from a prolamin source, the particles being thermoplastic and preferably having the ability to be extruded in an extrusion die, the method comprising: extruding the granules through a die, and The extruded material is deposited on the substrate, thereby obtaining the coated material.

15. The method according to any one of the preceding claims, in, The deposition is performed to provide a coating thickness in the range of 10 to 50 microns, preferably 20 to 25 microns.

16. A method according to any one of the preceding claims, in, The prolamin-based material comprises: Prolamins having the structure and distribution of naturally occurring prolamins; and Lipids with naturally occurring lipid structure and distribution.

17. A method according to any one of the preceding claims, in, The substrate is a vitamin-based substrate or a cardboard-based substrate.

18. A method according to any one of the preceding claims, in, The substrate is removed from the coating to obtain a coating comprising the properties / characteristics of the coating material.

19. A coated material comprising a substrate and a coating made from particles obtained from a prolamin source, the coated material having at least two of the following properties: - KIT value higher than 11; -WVTR value is strictly lower than 55g / m 2 / sky; -Cobb 1800 value strictly below 75g / m 2 ;as well as -Suitable heat sealing properties.

20. The coating material according to claim 19, comprising: -Cobb 1800 value strictly below 15g / m 2 .

21. Coated material obtained by the method according to any one of claims 1 to 18.

22. Use of a coated material obtained from the process of any one of the preceding claims for use in paper bags, shipping bags, frozen or non-frozen food containers.

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