WO2024153692A1 - Enzyme masterbatch comprising proteins - Google Patents

Abstract

The present invention relates to a masterbatch comprising a polymer, enzymes, plant and/or animal proteins, and optionally an inorganic filler. The masterbatch is used for the production of biodegradable plastic articles.

Description

Description

Title of the invention: ENZYME MASTERMIX COMPRISING PROTEINS

FIELD OF THE INVENTION

[1] The present invention relates to a masterbatch comprising a polymer, enzymes, plant and/or animal proteins and optionally a mineral filler. This masterbatch is used for the preparation of biodegradable plastic articles. The invention also relates to articles of biodegradable plastic material comprising a polymer and enzymes capable of degrading said polymer, plant and/or animal proteins and optionally a mineral filler.

BACKGROUND OF THE INVENTION

[2] Different biodegradable plastic compositions have been developed to respond to environmental issues, such as the accumulation of plastic items in landfills and natural habitats, and to legislation on short-lived products such as bags, packaging, trays, films, etc.

[3] The addition of additives (W02010/041063) and/or biological entities having the capacity to degrade polyesters (WO2013/093355, WO2016/198652, WO2016/198650, WO2016/146540, WO2016/062695) allows to obtain improved biodegradability compared to plastic articles lacking such biological entities.

[4] The use of biological entities assumes that the process for preparing biodegradable plastic articles ensures that the degradation activity of the biological entities is preserved. Processes for preparing these plastic materials have been described in which a polysaccharide or a mixture of polysaccharides is used in order to preserve the biological activity, and more particularly the degradation activity (WO2019/043145, WO2019/043134).

[5] It remains necessary to propose new solutions to promote the preparation of plastic articles under conditions which make it possible to preserve the enzymatic activity of the enzymes used, or even to improve them, while retaining mechanical and physicochemical properties appropriate for the uses of said articles.

BRIEF DESCRIPTION OF THE INVENTION

[6] The present invention relates to a masterbatch comprising:

60 to 95% support polymer,

0.01 to 8% enzymes,

1 to 15% vegetable and/or animal proteins, and

0 to 10% mineral filler, the percentages being expressed by weight relative to the total weight of the composition of the masterbatch.

[7] The invention also relates to a process for preparing said masterbatch, the process comprising the steps of mixing enzymes, animal and/or plant proteins and the support polymer in a mixer at a mixing temperature Tb, and recovery of the masterbatch.

[8] According to a preferred embodiment, the mixing temperature Tb is between 40 and 200°C, preferably between 55 and 175°C.

[9] According to another preferred embodiment, the mixer is an extruder.

[10] The invention also relates to the use of a masterbatch according to the invention in the manufacture of articles of biodegradable plastic material.

[11] The masterbatch can then be used in the manufacture of biodegradable plastic products or “end items”.

[12] The invention also relates to an article of biodegradable plastic material comprising the masterbatch and a polymer or a mixture of polymers capable of being degraded by the enzymes of said masterbatch.

[13] The invention also relates to an article of biodegradable plastic material comprising a polymer or a mixture of polymers and enzymes capable of degrading said polymers, plant and/or animal proteins and optionally a mineral filler.

DETAILED DESCRIPTION OF THE INVENTION

[14] Definitions [15] As used herein, the term "masterbatch" refers to a mixture of selected ingredients (e.g., enzymes, plant and/or animal proteins, additives, etc.) and a carrier polymer that may be used to introduce said ingredients into plastic articles in order to give them the desired properties. Advantageously, the masterbatch is composed of a support polymer in which the selected ingredients are incorporated at high concentration. The masterbatch compositions allow the process to economically introduce the selected ingredients during the process of manufacturing the plastic article. Generally, the masterbatch is intended to be mixed with one or more polymers or a polymer-based matrix to produce a final plastic article containing a desired quantity of selected ingredients.

[16] In the context of the invention, the term “enzymes” refers to enzymes having a polymer degradation activity and more particularly polyesters. The term “liquid enzyme formulation” or “enzymes in solution” refers to an enzyme solution and/or a suspension of enzymes in a solvent, in particular a thick suspension, capable of flowing at room temperature. The solvent is a solvent that does not degrade enzymes, particularly water. The form of the formulation will depend in particular on the enzyme content. It is understood that if the enzyme content exceeds the solubility threshold of the latter in the solvent, the formulation will include enzymes in suspension and will have the appearance of a thick composition, but nevertheless capable of flowing. According to an advantageous embodiment of the invention, the liquid enzymatic formulation is an enzymatic solution.

[17] The term “protein” refers to an organic polymer composed of amino acids linked together by peptide bonds and forming part or all of a protein molecule. The proteins used according to the invention have no enzymatic activity. So, these proteins are not enzymes. These proteins therefore do not have the capacity to degrade a polymer. The term “protein” refers to natural proteins, extracted from their natural environment, or fragments of said proteins.

[18] In the context of the invention, the term “plant protein” refers to proteins of plant origin, including cereals, oilseeds and legumes. They can thus be extracted from roots, stems, leaves, flowers or even fruits or seeds. Plant proteins can also come from algae.

[19] In the context of the invention, the term “animal protein” refers to proteins derived from animal sources, such as meat, eggs, fish, dairy products, and mixtures thereof. Preferably, animal proteins come from animal sources chosen from meat, fish, dairy products and mixtures thereof. In a particular and preferential mode, animal proteins come from dairy products (known as “milk proteins”).

[20] According to the invention, the term “plastic article” designates an article made from at least one polymer of defined shape. The plastic article is a manufactured product. The article is distinguished from the composition in that it has been shaped for a specific use, such as a sheet, film, tube, rod, profile, shape, solid block, fiber, etc. in plastic material.

[21] The term “plastic film” or “plastic film” refers to a flexible plastic film (i.e. capable of being folded without breaking) with a thickness of less than 250 pm. Thin films are considered to be less than 100 µm thick and are preferably produced by blown film extrusion while thick films are more than 100 µm thick and are preferably produced by cast film extrusion.

[22] According to the invention, the term “rigid article” or “rigid plastic article” refers to a plastic article which is not a film. These articles are preferably made by injection, thermoforming, blowing or even by rotational molding or 3D printing and can include sheets, trays, pots, etc.

[23] Unless otherwise indicated, percentages and relative ratios are expressed in mass relative to the total mass of the composition concerned.

[24] It is specified that the expressions "from... to..." and "between... and..." used in this description must be understood as including the limits mentioned. [25] In the context of the invention, the term "approximately" refers to a margin of +/- 5%, preferably +/- 1%, or within the tolerance of a suitable measuring device or instrument .

[26] Masterbatch

[27] The present invention relates to a masterbatch comprising:

60 to 95% support polymer, 0.01 to 8% enzymes,

1 to 15% vegetable and/or animal proteins, and

0 to 10% mineral filler, the percentages being expressed by weight relative to the total weight of the composition of the masterbatch.

[28] Support polymer

[29] The support polymer is a polymer with a low melting point, which thus advantageously has a melting temperature lower than 140°C, and/or a glass transition temperature lower than 70°C. The support polymer may also be a mixture of polymers including at least one polymer with a low melting point, which thus advantageously has a melting temperature of less than 140°C, and/or a glass transition temperature of less than 70°C. °C. The support polymer must also be compatible with the polymer(s) with which the masterbatch will be mixed for the preparation of enzymated plastic articles.

[30] Such support polymers are well known to those skilled in the art. These are in particular polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polydioxanone (PDS), polyhdroxyalkanoate (PHA), polylactic acid (PLA), or their copolymers.

[31] H can also be a natural polymer such as starch or even a polymer that we would describe as universal, that is to say compatible with a wide range of polymers such as an ethylene-acetate type copolymer vinyl (EVA).

[32] Advantageously, the support polymer has a melting temperature lower than 120°C and/or a glass transition temperature lower than 30°C. [33] The support polymer is generally a single polymer as defined above. It can also consist of a mixture of these support polymers.

[34] The support polymer is preferably chosen from PCL, PBS, PBSA, PB AT, PDS, PHA, PLA and their mixtures in all proportions.

[35] According to a particular embodiment of the invention, the support polymer is PCL. According to another particular embodiment of the invention, the support polymer is PLA.

[36] The masterbatch according to the invention comprises between 60 and 95% of support polymer. Thus, the masterbatch comprises at least 60% of support polymer, preferably at least 62%, more preferably at least 65% relative to the total weight of the composition. In parallel, the composition of the masterbatch comprises a content less than or equal to 95%, preferably less than or equal to 90% of support polymer. In one embodiment, the content of support polymer in the composition of the masterbatch is between 62 and 90%, between 65 and 90%, between 65 and 80%, and preferably between 65 and 75%. In another embodiment, the masterbatch comprises between 67 and 73%, or even between 68 and 72% of support polymer, the percentage being expressed by weight relative to the total weight of the composition. Advantageously, the masterbatch comprises approximately 70% support polymer.

[37] Enzymes

[38] The enzymes used are enzymes having a polymer degradation activity as defined below and more particularly polyesters. Their incorporation into plastic products based on polymers, in particular polyesters, thus makes it possible to improve the biodegradability of the latter.

[39] Examples of enzymes having polyester degradation activity are well known to those skilled in the art, in particular depolymerases, esterases, lipases, cutinases, carboxylesterases, proteases or polyesterases.

[40] Mention will be made in particular of enzymes capable of degrading polyesters so as to improve the biodegradability of articles prepared with the masterbatch according to the invention.

[41] In a particular mode, the enzymes have polylactic acid (PLA) degradation activity. Such enzymes and their method of incorporation into articles thermoplastics are known to those skilled in the art, in particular described in patent applications WO2013/093355, WO2016/198652, WO2016/198650, WO2016/146540 and WO2016/062695. The enzymes used in the context of the invention are in particular chosen from proteases and serine proteases. Examples of serine proteases are Proteinase K from Tritirachium album, or PLA-degrading enzymes from Amycolatopsis sp., Actinomadura keratinilytica, Laceyella sacchari LP 175, Thermus sp., or Bacillus licheniformis or reformulated and known commercial enzymes to degrade PLA such as Savinase®, Esperase®, Everlase® or any enzyme from the CAS [9014-01-1] subtilisin family or any functional variant.

[42] In a particular mode, the enzymes have a polybutylene adipate terephthalate (PB AT) degradation activity. The enzymes used in this particular mode of the invention are chosen in particular from esterases, preferably from cutinases and lipases. Examples of cutinases are cutinases derived from microorganisms selected from Thermobifida cellulosityca, Thermobifida halotolerans, Thermobifida fusca, Thermobifida alba, Bacillus subtilis, Fusarium solani pisi, Humicola insolens, Sirococcus conigenus, Pseudomonas mendocina, Thielavia terrestris, Saccharomonospora viridis, Thermomonospora curvata or all associated variant. In another embodiment, the cutinases used according to the invention are derived from a metagenomic library such as LC-Cutinase described in Sulaiman et al., Appl Environ Microbiol. 2012 Mar; 78(5): 1556-62. In yet another embodiment, the enzyme is an esterase as described in EP3517608, or any associated variant.

[43] Such enzymes are known to those skilled in the art, and in particular described in patent applications WO2018/011284, W02018/011281, W02021/005199, W02021/005198, W02022/090288, W02022/090289, W02022/090290 ,

W02022/090293.

[44] The enzymes used can be in solid form or in the form of a liquid enzyme formulation. For example, enzymes may be in powder form. For this purpose, the enzymes can be dried or dehydrated. Processes for drying or dehydrating enzymes are well known to those skilled in the art and include, but are not limited to, lyophilization, lyophilization, spray drying, supercritical drying, downdraft evaporation, thin film evaporation, centrifugal evaporation, conveyor drying, fluidized bed drying, drum drying or any combination thereof.

[45] The masterbatch comprises 0.01 to 8% of enzymes, the percentage being expressed by weight relative to the total weight of the composition of the masterbatch. In one embodiment, the enzyme content is between 0.02 and 6%, preferably between 0.05 and 5%. In particular, the masterbatch can include around 2% enzymes, around 3%, or even around 4% enzymes.

[46] According to one embodiment of the invention, the enzymes are not capable of degrading the support polymer. In particular, when enzymes are capable of degrading PLA, the support polymer is not PLA or does not include PLA.

[47] According to another embodiment of the invention, the enzymes are capable of degrading the support polymer or one of the components of the support polymer when the latter is a mixture of polymers. In particular, when enzymes are capable of degrading PLA, the support polymer is PLA or includes PLA. Advantageously, the enzymes are capable of degrading PLA having a melting temperature greater than 140°C and the support polymer is PLA or comprises PLA having a melting temperature less than or equal to 140°C.

[48] Plant and/or animal proteins

[49] The masterbatch also includes animal and/or vegetable proteins. These plant and/or animal proteins, according to the invention, do not have enzymatic activity. These are in particular structural proteins, whole or partially degraded. For the avoidance of doubt, plant and/or animal proteins are different from enzymes having polymer degradation activity and said enzymes having polymer degradation activity are not included in the definition of plant and/or animal proteins. According to the invention, the animal and/or plant proteins can be native or modified. It can also be hydrolyzed proteins.

[50] By “proteins” used according to the invention we essentially mean “protein compositions” comprising native, modified proteins, in particular hydrolyzed proteins, and other components associated with the method of preparation of protein, isolation and/or modification, particularly from fat, ash and moisture. Among the proteins which can be used according to the invention there are numerous protein compositions, in particular isolates or concentrates of plant and/or animal proteins or even hydrolysates of plant and/or animal proteins. These proteins can be of different concentrations in the protein compositions.

[51] The protein compositions are preferably in solid form, in particular powdery form.

[52] In general, the protein concentration in the protein compositions is greater than or equal to 35% by dry weight, preferably greater than 60%, even more preferably greater than or equal to approximately 70%, approximately 72%, about 74%, about 76%, about 77%, about 80%, or about 88%. According to a preferred embodiment, the concentration of animal and/or plant proteins in the protein compositions is between 35 to 95% by dry weight, preferably between 65 and 90%, even more preferably, between 80 and 90%.

[53] Generally speaking, for commercially available protein compositions, isolates have a protein concentration greater than 80% by dry weight and concentrates have a protein concentration greater than 50% by dry weight.

[54] According to the invention, isolates whose protein content is greater than 80% by dry weight are particularly preferred.

[55] The protein concentration in protein compositions is expressed as dry weight on a dry matter basis. In the context of the invention, animal proteins are preferably chosen from gelatin, collagen, milk proteins, and mixtures thereof. More preferably, animal proteins are milk proteins.

[56] By “gelatin” we mean the proteins produced during the partial hydrolysis of collagen extracted from the skin, bones and connective tissues of animals. Gelatin can be derived from any type of collagen (collagen type I, II, III or IV).

[57] Milk proteins may be proteins extracted from milk or preparations comprising milk. Preferably, the milk is animal milk. According to a mode of preferred embodiment, the milk is cow's, sheep's, goat's, buffalo's, camel's or mare's milk, preferably the milk is cow's milk.

[58] Milk proteins include casein proteins and seroproteins (or serum proteins) which are found in whey. More particularly, milk proteins include casein proteins, including in particular a-caseins, P-caseins, y-caseins and K-caseins, but also P-lactoglobulin, a-lactalbumin, glycomacropeptide. , immunoglobulins, serum albumin and lactoferrin of any mammalian species.

[59] Caseins can also be found in the form of salts like sodium caseinate, calcium caseinate, etc.

[60] By “milk proteins” we also mean whey proteins (or whey proteins in English) which corresponds to a mixture of globular proteins obtained from whey. These proteins can be fully or partially purified by removing sufficient non-protein constituents from the whey.

[61] Such proteins are commercially available in the form of whey protein concentrates (WPC or Whey Protein Concentrates in English), whey protein isolates (WPI or Whey Protein Isolates in English) or hydrolyzate of whey protein. The composition thus varies depending on the type of milk and the animal that produced it. The methods for preparing whey proteins are those usually used in the art. In general, the proteins are obtained by one or more techniques known to those skilled in the art, in particular chosen from ultrafiltration, microfiltration, enzymatic hydrolysis, chromatography, electrodialysis, evaporation and osmosis. reverse.

[62] Whey protein hydrolyzate is a pre-treated protein that has undergone a preliminary enzymatic hydrolysis step.

[63] Whey protein concentrates can be obtained by a more or less significant elimination (precipitation, filtration or dialysis) of the non-protein constituents of the whey, so as to obtain a concentration of at least 25% by dry weight of proteins. , particularly in powder form. According to one embodiment, the concentrates contain a concentration by dry weight of proteins between 30 and 90% by weight, preferably greater than 60%, more preferably greater than approximately 70%. [64] Whey protein isolates can be obtained after several successive filtrations (ultrafiltration/diafiltration). They can also be obtained for example by chromatography on ion exchange resins. According to a preferred embodiment, the isolates have a protein concentration greater than or equal to approximately 80% by dry weight. Preferably, this concentration is greater than or equal to approximately 85% by dry weight.

[65] Such proteins are also commercially available. We will cite in particular Caseine pressure, Euridiet 80NS and GrassFit™ 80WPC marketed by Eurial®, IWPC 80 SH and IWPI 90 SH marketed by Lactoland, gelatins of bovine or porcine origin marketed under the references Stabicaps, Simogel and Emulsigel by the company Rousselot .

[66] Sources of plant proteins include legumes such as peas (split peas, mung peas, chickpeas, etc.), beans, lentils, soya; oilseed fruits, such as nuts (walnuts, Brazil nuts, cashews, etc.), hazelnuts, peanuts, almonds, pistachios, etc. ; cereals such as rice, wheat, corn; seeds such as oats, buckwheat, sesame, pumpkin seeds, sunflower seeds, flax seeds, poppy seeds or even hemp seeds, etc. ; and fruit.

[67] The plant proteins used according to the invention can be in the form of plant protein isolates or concentrates or even plant protein hydrolysates.

[68] Generally speaking, plant protein hydrolysates are obtained in an aqueous medium from the corresponding plant proteins in the crude state via a hydrolysis reaction, such as acid hydrolysis, basic hydrolysis or enzymatic hydrolysis of plant proteins. .

[69] The methods for preparing plant protein concentrates and isolates are those usually used in the art.

[70] Plant proteins are also commercially available. We will cite in particular rice proteins marketed under the references Brown rice protein powder by the company NP Nutra or Rice Protein R80+, H70+, H60+ by the company IIC Ingredients, pea proteins marketed under the references Pea protein powder 80% by the company NP Nutra, or Pea Protein P80+, Fave bean protein, Chickpea protein and Mung bean protein by the company IIC Ingredients.

[71] In a preferred embodiment, the vegetable proteins used in the master mix are chosen from pea proteins, and preferably from mung pea proteins and chickpea proteins, bean proteins, soy proteins. and rice proteins. Plant protein isolate includes pea protein isolate, potato protein isolate, gluten and/or soy protein isolate.

[72] In the context of the invention, the masterbatch can comprise only animal proteins or only vegetable proteins. The masterbatch may also include a mixture of animal and vegetable proteins.

[73] It is understood that animal and/or plant proteins may include animal and/or plant proteins originating from a single animal or plant source respectively, or from several animal and/or plant sources. We will therefore cite as combinations of animal proteins that can be used in the composition of the master mix: casein / gelatin, casein / collagen, milk protein isolate / gelatin, milk protein isolate / collagen, serum albumin / gelatin, etc. Examples of plant protein blend are rice protein/pea protein, etc.

[74] The masterbatch comprises 1 to 15% vegetable and/or animal proteins. In one embodiment, the protein content is greater than 1% and preferably greater than 2%. In another embodiment, the masterbatch comprises between 3 and 15% proteins, which may be of animal or plant origin. In a preferred embodiment, the protein content is between 3 and 13%, preferably between 3 and 10%. In another embodiment, the masterbatch comprises between 3 and 9% proteins, between 3 and 8% proteins, or even between 3 and 7% vegetable and/or animal proteins, relative to the total weight of the composition. . Advantageously, the masterbatch comprises approximately 3%, approximately 3.5%, approximately 4%, approximately 4.5%, approximately 5%, approximately 5.5%, approximately 6%, approximately 6.5%, approximately 7%, approximately 7.5%, approximately 8% vegetable and/or animal proteins.

[75] Polysaccharide [76] The masterbatch may further comprise one or more polysaccharides.

[77] In the context of the invention, the term “polysaccharides” refers to molecules composed of long chains of monosaccharide units linked together by glycosidic bonds. The structure of polysaccharides can be linear to highly branched. Examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin. Polysaccharides include native polysaccharides or polysaccharides chemically modified by cross-linking, oxidation, acetylation, partial hydrolysis, etc.

[78] Carbohydrate polymers can be classified based on their source (marine, plant, microbial or animal), structure (linear, branched) and/or physical behavior (such as designation as gum or hydrocolloid which refers to the property that these polysaccharides hydrate in hot or cold water to form solutions or viscous dispersions with low gum or hydrocolloid concentration).

[79] In the context of the invention, polysaccharides can be classified according to the classification described in “Encapsulation technologies for active food ingredients and food processing - Chapter 3 - Materials for encapsulation; Christine Wandrey, Artur Bartkowiak and Stephen E. Harding" and include: starch and derivatives, such as amylose, amylopectin, maltodextrin, glucose syrups, dextrin, cyclodextrin or even pullulan, cellulose and derivatives, such as methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, etc., plant exudates and extracts, also called plant gums or natural gums, including but not limited to gum arabic (or gum acacia), tragacanth gum, guar gum, locust bean gum, karaya gum, mesquite gum, galactomannans, pectin, soluble soy polysaccharide or even konjac, marine extracts such as carrageenan and alginate, microbial and animal polysaccharides such as gellan, dextran, xanthan, chitosan.

[80] Polysaccharides can also be classified based on their water solubility. In particular, cellulose is not soluble in water. According to the invention, the polysaccharides have the ability to be soluble in water.

[81] When present, the polysaccharides used in the formulation of plastic compositions are chosen from starch derivatives such as amylose, amylopectin, maltodextrins, glucose syrup, dextrins, cyclodextrins or pullulan, gums natural such as gum arabic, tragacanth gum, guar gum, locust beam gum, karaya gum, mesquite gum, galactomannans, pectin or soluble soy polysaccharides, or konjac, marine extracts such as carrageenans and alginates, and microbial or animal polysaccharides such as gellans, dextrans, xanthans or chitosan, and mixtures thereof. The polysaccharide can also be a mixture of several polysaccharides mentioned above.

[82] Advantageously, the polysaccharide used is a natural gum, and more particularly gum arabic.

[83] When present, the polysaccharide content in the masterbatch is less than 10%, preferably less than 9% by weight relative to the total weight of the composition. In another embodiment, the masterbatch comprises between 0 and 8% of polysaccharides, preferably between 0 and 7% by weight relative to the total weight of the composition. Advantageously, the masterbatch comprises between 2 and 7% by weight relative to the total weight of the composition. In a particular embodiment, the masterbatch comprises between 3 and 7% polysaccharides. In another embodiment, the polysaccharide content is approximately 2%, approximately 3.5%, approximately 5%, or approximately 7%, the percentage being expressed by weight relative to the total weight of the masterbatch composition. .

[84] Mineral filler

[85] The masterbatch may also include a mineral filler.

[86] Several minerals can be used. Examples are calcite, carbonate salts or carbonate metals such as calcium carbonate, potassium carbonate, magnesium carbonate, aluminum carbonate, carbon dioxide zinc, copper carbonate, chalk, dolomite; silicate salts, such as calcium silicate, potassium silicate, magnesium silicate, aluminum silicate, or a mixture thereof, such as micas, smectites such as montmorillonite, vermiculite, and sepiolite-palygorskite; sulfate salts, such as barium sulfate or calcium sulfate (gypsum), mica; hydroxide salts or hydroxide metals such as calcium hydroxide, potassium hydroxide (potash), magnesium hydroxide, aluminum hydroxide, sodium hydroxide (caustic soda), hydrotalcite; oxide metals or oxide salts such as magnesium oxide, calcium oxide, aluminum oxide, iron oxide, copper oxide, clay, asbestos, silica, graphite, carbon black; metal fibers or metal petals; glass fibers; magnetic fibers; ceramic fibers and derivatives and/or mixtures thereof.

[87] In a preferred embodiment, the mineral filler used is calcium carbonate or talc. Advantageously, the mineral filler is calcium carbonate.

[88] The quantity of mineral filler is between 0 and 10% by weight relative to the total weight of the composition. Preferably, the mineral filler content is greater than 2%, or even greater than 5%. In a preferred embodiment, the mineral filler content is approximately 10% by weight relative to the total weight of the composition of the masterbatch.

[89] Advantageously, the composition of the plastic article comprises less than 20% by weight of mineral filler and preferably less than 15% relative to the total weight of the masterbatch. In general, the composition of the article can include from 4% to 15% by weight of mineral filler relative to the total weight of the composition of the article.

[90] Process for preparing the masterbatch

[91] The process for preparing the masterbatch comprising enzymes, animal and/or plant proteins and a support polymer in a mixer, comprises the steps of mixing the enzymes, the animal and/or plant proteins and the support polymer at a mixing temperature Tb and recovery of the masterbatch. [92] According to a particular method, the enzymes are added to the mixer in powder form.

[93] According to another particular method, the enzymes are added in the form of a liquid enzyme formulation. The amount of liquid enzyme formulation added for the preparation of the masterbatch will depend on the enzyme content in said liquid enzyme formulation and the final enzyme content desired in the masterbatch.

[94] According to one embodiment of the invention, the quantity of liquid enzymatic formulation added for the preparation of the master mix varies between 0.1 and 25% by weight relative to the total weight of the composition, in particular from 3 to 20%, more particularly between 5 and 18%.

[95] According to one embodiment of the invention, the liquid formulation essentially consists of enzymes and the solvent, in particular water.

[96] According to one embodiment, the liquid enzymatic formulation comprises from 0.1 to 40% by weight of enzymes relative to the total weight of the liquid enzymatic formulation, in particular from 3 to 35% of enzymes, more particularly between 10 and 30% enzymes.

[97] According to one embodiment, the liquid enzyme formulation is a solution essentially comprising enzymes and water.

[98] According to another embodiment, the liquid enzyme formulation is a suspension essentially comprising enzymes and water.

[99] The enzymes are added by any usual means of introduction into a mixer or any other industrial means such as a doser specific to powders, a peristaltic pump or an injector. Those skilled in the art will be able to determine which device is most appropriate for enzymes in powder form or in the form of a formulation. In a preferred embodiment, the enzymes in liquid formulation are introduced into the mixer via a peristaltic pump.

[100] In another embodiment, the enzymes in powder form are introduced into the mixer via a doser specific to powders.

[101] The vegetable and/or animal proteins are added in an appropriate form, in particular powder, via a specific doser. [102] The amount of protein composition added for the preparation of the masterbatch will depend on the protein content in said protein composition and the final protein content in the masterbatch.

[103] The support polymer is in the form of granules and, in a particular mode, is introduced into the mixer via a doser specific to the granules. In another particular mode, the support polymer is introduced into the mixer in a partially or completely molten form.

[104] According to a particular embodiment, the masterbatch is prepared by mixing:

60 to 95% support polymer,

8 to 20% enzymatic solution, and

1 to 15% animal and/or vegetable proteins, possibly a mineral filler, the percentages being expressed by weight relative to the total weight of the composition.

[105] Enzymes in liquid formulation on the one hand and animal and/or vegetable proteins on the other hand can be introduced separately or simultaneously into the mixer. The two components can thus be introduced consecutively, that is to say one after the other, or simultaneously. We can first introduce the enzymes in solution, then the proteins, or first the proteins and then the enzyme solution.

[106] The masterbatch formulation may include a mineral filler and/or a polysaccharide, and/or other additives, which are mixed with the other compounds in an appropriate sequence determined by those skilled in the art.

[107] The mixing is done at a mixing temperature Tb at which the support polymer is partially or completely melted. In a particular mode, it is understood that the mixing temperature Tb is a temperature at which the enzymatic activity is preserved, and more particularly a temperature which does not substantially reduce the enzymatic activity of degradation of the support polymer.

[108] According to a particular embodiment, the mixing temperature Tb is a temperature less than or equal to the melting temperature (Tm) of the support polymer. Those skilled in the art will be able to choose the support polymer according to its melting temperature. and the ability of the chosen enzymes to withstand this temperature in the process according to the invention. In a particular mode, the mixing temperature Tb is between the glass transition temperature (Tg) and the melting temperature (Tm) of the support polymer. Alternatively, the mixing temperature Tb is set at a temperature equal to or above the melting temperature of the support polymer.

[109] Generally speaking, the mixing temperature Tb can be between 40 and 200 °C. In one embodiment, the temperature is greater than 40°C, or even greater than 50°C. The temperature is preferably between 55 and 175°C. In a preferred embodiment, the mixing temperature Tb is adjusted according to the nature of the polymer used. Thus, the mixing temperature Tb is generally located or corresponds to the melting temperature of the polymer used. Typically, the temperature does not exceed 300°C, more particularly, the temperature does not exceed 250°C.

[110] We will seek to maintain a temperature of the mixture Tb which is as low as possible while allowing homogeneous mixing and dispersion of the enzymes and the polysaccharide in the support polymer.

[111] In a particular mode, the support polymer is PCL and the mixing temperature Tb is between 55 and 65 °C, particularly around 60 °C.

[112] The mixing of the enzyme, protein and support polymer components is carried out for a period of 10 to 35 seconds. In a particular mode, the mixing lasts between 15 and 35 seconds, in particular about 20 seconds, about 25 seconds or about 30 seconds.

[113] In particular, the temperature is gradually increased in order to ensure homogeneous and constant mixing while best preserving the characteristics and properties of each of the components.

[114] Advantageously, the residence time of the enzyme/protein composition in the polymer at a temperature above 100°C within the mixer for the mixing step is as short as possible. It is preferably between 5 seconds and 10 minutes. However, a residence time of less than 5 minutes is preferred. In a preferred embodiment, this is less than 3 minutes, and possibly less than 2 minutes. [115] According to a particular embodiment, the process for preparing the masterbatch comprises the steps of: a) introducing enzymes, animal and/or plant proteins and the support polymer at a first temperature Ta in a mixer, b) mixing the components at the mixing temperature Tb, and c) recovering the masterbatch.

[116] Step (a) corresponds to the addition of the animal and/or plant proteins, the support polymer and the enzymes, preferably in solution, in the mixer.

[117] Advantageously, the introduction of these compounds is done at low temperature, preferably at a temperature Ta lower than the mixing temperature Tb, in particular melting of the support polymer. The temperature Ta is thus between 25 and 80°C. In a preferred embodiment, the temperature is between 25 and 50°C. The mixing of the enzymes, preferably in solution, and the proteins is done for a period of less than 30 seconds, more particularly in less than 25 seconds, and preferably for a period of approximately 20 seconds.

[118] A person skilled in the art will be able to adapt the characteristics of the process (temperature and time) necessary for carrying out step (a) depending on the components used (enzymes, proteins and support polymer).

[119] The recovered masterbatch is in solid form. It is advantageously recovered in the form of granules. These granules can be stored, transported, and incorporated into the manufacture of plastic products or articles, whatever their form and use, which can be called “final products”. These may be films, or flexible or solid parts with shapes and volumes adapted to their uses.

[120] According to a preferred embodiment, the process for preparing the masterbatch comprising enzymes, plant and/or animal proteins, and the support polymer in a mixer, comprises the following steps of: a) introducing the enzymes and vegetable and/or animal proteins at a mixing temperature Ta; b) introduction of the support polymer; c) mixing the components at the mixing temperature Tb at which the support polymer is partially or completely melted; d) recovery of the masterbatch.

[121] Advantageously, the enzymes in solution and the animal and/or plant proteins are introduced simultaneously into the mixer.

[122] The masterbatch formulation may include a mineral filler. In this case, the mineral compound is introduced in step (a), with the addition of proteins and enzymes to the mixer.

[123] In the same way, when the masterbatch includes a polysaccharide, the latter is introduced into the mixer during step (a). Advantageously, the animal and/or plant proteins and the polysaccharide are then added during step (a) in the form of a mixture.

[124] Those skilled in the art know different types of mixers that can be used for the manufacture of these polymer masterbatches.

[125] In a preferred embodiment, the mixer is an extruder. This can be of the single screw or twin screw type. It is preferably of the twin screw type.

[126] In particular, the process is implemented in an extruder comprising at least 4 zones, a head zone where the first components are introduced, an intermediate zone where other components are added, a mixing zone and a zone outlet through which the master mix is recovered, with the following steps a) to d): a) the separate introduction of animal and/or plant proteins on the one hand and an enzymatic solution on the other hand into the processing zone head and where appropriate a mineral filler and/or polysaccharide at a temperature Ta; b) the introduction of a support polymer into the intermediate zone in a partially or completely molten form; c) mixing the components in the mixing zone at a temperature Tb at which the support polymer is partially or completely melted; d) recovery of the masterbatch leaving the extruder.

[127] Alternatively, the process is implemented in an extruder comprising at least 3 zones, a head zone where the first components are introduced, a mixing zone and an outlet zone through which the masterbatch is recovered, with the following steps: a) the separate and simultaneous introduction into the head zone of an enzymatic solution, animal and/or vegetable proteins and the polymer support, and where appropriate a mineral filler and/or polysaccharide at a temperature Ta; b) mixing the components in the mixing zone at a temperature Tb at which the support polymer is partially or completely melted; c) recovery of the masterbatch leaving the extruder.

[128] The person skilled in the art will know how to adapt the characteristics of the extruder (The length and diameter of the screw(s), the screw elements, the degassing zones, etc.) and the residence time of the different components (enzymes, proteins and the support polymer) depending on the time and temperature constraints of the different stages of the process of the invention.

[129] In particular, the temperature in the head zone is lower than the melting temperature of the support polymer and the temperature of the mixing zone is higher than the temperature of the head zone, in particular as defined above for the temperatures mixture.

[130] The mixing zone can itself include several zones and those skilled in the art will be able, if necessary, to adapt the temperatures of each zone in particular according to the enzymes and support polymers used.

[131] The masterbatch can be obtained in the form of granules prepared according to the usual techniques. These granules can be stored, transported and used in the manufacture of biodegradable plastic articles, which can be called “final articles”. These may be films or flexible or solid parts with shapes and volumes adapted to their uses.

[132] When in granular form, the masterbatch can be dried for storage. The drying methods are usual methods known to those skilled in the art, in particular with the use of hot air ovens, vacuum ovens, desiccators, microwaves or fluidized beds. The drying temperature and its duration will depend on the one hand on the water content provided by the enzymatic solution in the preparation of the masterbatch, but also on the melting and glass transition temperatures of the support polymer used.

[133] The humidity level is generally 0.5% or less and preferably less than 0.3%.

[134] Enzymized plastic articles [135] The enzymized plastic articles according to the invention can be films, flexible or solid parts of shapes and volumes adapted to their uses. Examples of biodegradable plastic articles concerned by the invention are films, mulching films, routing films, food or non-food films; packaging such as packaging blisters, trays; disposable tableware such as cups, plates or even cutlery; caps and lids; drink capsules; and horticultural items.

[136] Advantageously, the composition of the plastic article is as follows:

60 to 98% biodegradable polymer,

0.01 to 20% support polymer,

0.01 to 8% enzymes,

0 to 35% mineral charge,

0.01 to 5% vegetable and/or animal proteins,

0 to 5% additives, and

0 to 5% polysaccharide, the percentages being expressed by weight relative to the total weight of the composition.

[137] Biodegradable Polymer

[138] The biodegradable polymer is a polymer, or a mixture of polymers, capable of being degraded by the enzymes used in the composition of the final article.

[139] The biodegradable polymer is different from the support polymer. It may comprise a polymer of the same chemical composition, but with different physicochemical properties in terms of size and/or melting temperature. In particular, when the biodegradable polymer comprises a polymer of the same chemical composition as the support polymer or as one of the polymers composing the support polymer, then the latter has a melting temperature of at least 140 ° C, and/or a glass transition temperature of at least 70°C.

[140] Those skilled in the art will choose the composition of the biodegradable polymer based on the structure and use of the biodegradable article and in particular based on its mechanical properties.

[141] Advantageously, said biodegradable polymer is a biodegradable polyester. These polyesters are well known to those skilled in the art, such as polybutylene adipate terephthalate (PBAT), polyhydroxyalkanoate (PHA), poly P-hydroxybutyrate (PHB), polyhydroxyhexanoate (PHH), polybutylene succinate (PBS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate adipate (PBSA) and plasticized starch and mixtures thereof.

[142] These polyesters are chosen for their physicochemical properties depending on the final article and the properties that will be sought, in particular its mechanical properties but also their color or transparency.

[143] In a preferred embodiment, the enzyme-degradable polyester comprises PLA, alone or in a mixture with another polyester above, in particular a PLA/PBAT mixture.

[144] In one embodiment, the biodegradable polyester is a PBAT/PLA mixture whose weight ratio ranges from 10/90 to 20/80, and preferably from 13/87 to 15/85.

[145] In another embodiment, the biodegradable polyester is a PBAT/PLA mixture whose weight ratio ranges from 10/90 to 30/70, from 10/90 to 40/60, from 10/90 to 50/50 , from 10/90 to 60/40, from 10/90 to 70/30, from 10/90 to 80/20, from 10/90 to 90/10.

[146] Still, in another embodiment, the biodegradable polyester is a PBAT/PLA mixture whose weight ratio is less than 10/90, equal to or less than 9/91, equal to or less than 8/92, equal or less than 7/93, equal to or less than 6/94, equal to or less than 5/95, equal to or less than 4/96, equal to or less than 3/97, equal to or less than 2/98, equal to or less than 1/99.

[147] In another embodiment, the biodegradable polyester is PLA.

[148] Enzymed biodegradable plastic articles as defined can be flexible and/or rigid, the thickness of which then varies between 10 pm and 5 mm.

[149] Flexible or rigid articles, single-layer or multi-layer, may include a combination of PLA with PHA in order to improve their barrier properties, as described in patent applications FR2209252, filed on September 14, 2022 and FR2209254, filed on September 14, 2022.

[150] These articles of flexible biodegradable plastic material are characterized by a thickness of less than 250 pm, preferably by a thickness of less than 200 pm. In a preferred embodiment, the films have a thickness of less than 100 pm, more preferably less than 50 pm, 40 pm or 30 pm, preferably between 10 and 20 m. More preferably, the thickness of the flexible article is 15 μm.

[151] Examples are films, such as food films, routing films, industrial films or mulch films and bags.

[152] Advantageously, the composition of the flexible article comprises:

70 to 98% biodegradable polymer(s),

0.1 to 20% support polymer,

0.01 to 20% enzymes,

0.01 to 5% animal and/or vegetable proteins,

0 to 35% mineral charge,

0 to 5% polysaccharide, and

0 to 5% additives, the percentages being expressed by weight relative to the total weight of the composition.

[153] The rigid articles have a thickness of between 200 pm and 5 mm, between 150 pm and 5 mm, preferably between 200 mm and 3 mm, or between 150 pm and 3 mm. In one embodiment, the articles have a thickness of between 200 pm and 1 mm, between 150 pm and 1 mm, preferably between 200 pm and 750 pm or between 150 pm and 750 pm. In another embodiment, the thickness is 450 μm.

[154] Examples of such biodegradable plastic articles are cups, plates, cutlery, trays, drink capsules and packaging blisters, more generally food or cosmetic packaging, or horticultural products .

[155] Concerning rigid articles, the biodegradable polyester is PLA, and preferably a PLA/calcium carbonate mixture whose weight ratio ranges from 100/0 to 25/75, preferably from 95/5 to 45/55, more preferably from 90/10 to 50/50. In another embodiment, the biodegradable polyester is a PBAT/PLA mixture whose weight ratio preferably ranges from 10/90 to 80/20, more preferably from 20/80 to 60/40.

[156] Advantageously, the composition of the rigid article comprises:

80 to 98% biodegradable polymer(s), 0.1 to 20% support polymer, 0.01 to 8% enzymes, 0.01 to 5% animal and/or vegetable proteins,

0 to 35% mineral charge,

0 to 5% polysaccharide, and 0 to 5% additives, the percentages being expressed by weight relative to the total weight of the composition.

[157] The composition according to the invention is particularly suitable for the production of plastic films. The films according to the invention can be produced according to the usual methods of the technique, in particular by extrusion-inflation. The films can be prepared from granules of composition according to the invention which are melted according to the usual techniques, in particular by extrusion.

[158] Films of composition as defined above with enzymes can be single-layer or multi-layer films. In the case of a multilayer film, at least one of the layers has a composition as defined above. The single-layer and multi-layer films, of composition as defined above, have both a high PLA content and retain mechanical properties such as those sought for the preparation of biodegradable and bio-sourced films, in particular for the packaging of food and non-food products. .

[159] The multilayer film can be a film comprising at least 3 layers, of the ABA, ABCA or ACBCA type, the layers A, B and C being of different compositions.

[160] Generally layers A and B comprise one or more biodegradable polyesters.

[161] In the case of multilayer films, the enzymes can be present in all the layers or in only one of the layers, for example in layers A and B or only in layer A or in layer B.

[162] Layer A may also include other additives customary in the preparation of plastic articles, such as those defined above, in particular plasticizers and compatibilizers.

[163] Layer B includes at least 0.001% enzymes capable of degrading the biodegradable polymers of layers A and B, whether adjacent or separated by a layer C. [164] Layer B, in addition to the enzymes, includes polymers constituting this layer. These constituent polymers are chosen from polymers likely to be degraded by the enzymes they contain. These polymers are in particular the polyesters defined above. These constituent polymers can also be chosen from barrier materials such as polyvinyl alcohol (PVOH), polyvinyl chloride (PVCD), polyglycolic acid (PGA), cellulose and its derivatives, or polysaccharides and their mixtures in all proportions, used alone or mixed with the aforementioned polyesters.

[165] The C layers, if present, are there to provide particular properties to the articles according to the invention, more particularly to provide barrier properties to gases and in particular to oxygen. Such barrier materials are well known to those skilled in the art, and in particular PVOH (poly vinyl alcohol), PVCD (poly vinyl chloride), PGA (polyglycolic acid), cellulose and its derivatives, or polysaccharides and their mixtures in all proportions.

[166] The PVOH used as a barrier material in the preparation of the article is well known. It is polyvinyl alcohol with a degree of polymerization between 300 and 2500, a melting point below 210°C and a viscosity between 3 and 60 mPa.s.

[167] PVCD corresponds to polyvinylidene chloride resulting from the copolymerization of vinylidene chloride (85%) and vinyl chloride (15%).

[168] The PGA used as a barrier material is polyglycolic acid whose melting temperature is 220 °C and the glass transition temperature is 40 °C.

[169] Among the celluloses and derivatives, mention will be made in particular of microfibrillated celluloses (MCF) and cellulose acetate. The MCFs used as barrier materials have a diameter between 4 and 10006 nm and a density between 0.51 and 1.57 g/cm ³ .

[170] The polysaccharides used as barrier materials are also known to those skilled in the art, and mention will be made more particularly of galactomannans, pectin or soluble soy polysaccharides, marine extracts such as carrageenans and alginates, and microbial polysaccharides. or animals such as gellans, dextrans, xanthans, xylans or chitosan and their mixtures. Tl

[171] Layer C may also include usual additives used in the preparation of plastic articles, such as slippery agents, plasticizers, nucleating agents, compatibilizers, UV radiation stabilizers, antiblocking agents, aids during manufacturing, mineral and/or vegetable fillers, etc.

[172] According to a preferred embodiment, the composition of layer C comprises 90 to 100% of barrier materials as defined above, and 0 to 10% of additives.

[173] Additives

[174] The enzymatic plastic article according to the invention may also include one or more additives in its composition. Generally speaking, additives are used to improve specific properties of the final product.

[175] The additives can thus be chosen from plasticizers, coloring agents, technological aids, rheological agents, antistatic agents, anti-UV agents, reinforcing agents, compatibility agents, retarding agents flame retardants, antioxidants, pro-oxidants, light stabilizers, oxygen traps, adhesives, products, excipients, or even additives to improve barrier properties to water or gases, such as polyhydroxyalkanoates, etc.

[176] Advantageously, the composition of the plastic article comprises less than 20% by weight of additives and preferably less than 10% relative to the total weight of the masterbatch. In general, the composition of the article includes 0% to 10% by weight of additives relative to the total weight of the composition of the article.

[177] Examples of plasticizers are citrate esters and lactic acid oligomers (OLA).

[178] Citrate esters are plasticizers known to those skilled in the art, in particular as biosourced materials. These include triethyl citrate (TEC), triethyl acetyl citrate (TEAC), tributyl citrate (TBC), tributyl acetyl citrate (TB AC). Preferably, the citrate ester used as plasticizer in the composition according to the invention is TB AC.

[179] Lactic acid oligomers (OLA) are also plasticizers known to those skilled in the art, in particular as biosourced materials. These are oligomers lactic acid with a molecular weight of less than 1500 g/mol. They are preferably esters of lactic acid oligomers, their carboxylic acid ending being blocked by esterification with an alcohol, in particular a linear or branched Cl -CIO alcohol, advantageously a C6-C10 alcohol, or a mixture of these latter. We will cite in particular the OLAs described in patent application EP 2256 149 with their method of preparation, and the OLAs marketed by the company Condensia Quimica under the brand Glyplast®, in particular the references Glyplast® OLA 2, which has a molecular weight of 500 to 600 g/mol and Glyplast® OLA 8 which has a molecular weight of 1000 to 1100 g/mol. According to a preferred embodiment of the invention, the OLAs have a molecular weight of at least 900 g/mol, preferably from 1000 to 1400 g/mol, more preferably from 1000 to 1100 g/mol.

[180] Among the additives, compatibilizers or compatibilizers can be used in the masterbatch.

[181] Poly (propylene glycol) diglycidyl ether (PPGDGE) are also called glycidyl ethers, described in particular as “reactive plasticizers” in patent application WO 2013/104743, used for the preparation of block copolymers with PLA and PBAT. They are also identified as liquid epoxy resin, from the company DOW, marketed under the reference “D.E.R.™ 732P”, or as aliphatic epoxy resin, from the company HEXION, marketed under the reference “Epikote™ Resin 877”.

[182] The composition of the article according to the invention may optionally comprise other PLA/Polyester compatibilizers associated with PPGDGE. Such PLA/Polyester compatibilizers are well known to those skilled in the art, in particular chosen from poly acrylates, terpolymers of ethylene, acrylic ester and glycidyl methacrylate (for example marketed under the brand Lotader® by the company Arkema), PLA-PBAT-PLA triblock copolymers, PLA grafted with maleic anhydride (PLA-g-AM) or PBAT grafted with maleic anhydride (PBAT-g-AM). In particular, the compatibilizers are chosen from poly acrylates, and advantageously selected from methacrylate derivatives. Preferably the compatibilizer is poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate) described in particular by Dong et al. (International Journal of Molecular Sciences, 2013, 14, 20189-20203) and Ojijo et al. (Polymer 2015, 80, 1-17). A preferred compatibilizer is poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate) sold under the name JONCRYL® ADR-4468 by the company BASF.

[183] Preparation of articles

[184] The biodegradable plastic article is obtained by mixing the masterbatch comprising the enzymes with at least one polymer capable of being degraded by said enzymes.

[185] The process for preparing the plastic article thus comprises the steps i) of preparing a masterbatch comprising enzymes capable of degrading said polymer, animal and/or plant proteins, a support polymer, and optionally a mineral filler, as defined above, and ii) mixing said masterbatch with a polymer capable of being degraded by said enzymes included in the masterbatch.

[186] Advantageously, said polymer capable of being degraded by enzymes, or biodegradable polymer, is a biodegradable polyester. These polyesters are well known to those skilled in the art, such as polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipase (PBSA), polybutylene adipate terephthalate (PB AT), plasticized starch and mixtures thereof.

[187] These polyesters are chosen for their physicochemical properties depending on the final article and the properties that will be sought, in particular its mechanical properties but also their color or transparency.

[188] The biodegradable polyesters used for the preparation of the final articles have physicochemical properties identical or different from the polyesters used as support polymers in the masterbatch according to the invention.

[189] In a preferred embodiment, the enzyme-degradable polyester comprises PLA, alone or in a mixture with another polyester above, in particular a PLA/PBAT mixture.

[190] The biodegradable plastic article is thus made up of the masterbatch and a biodegradable polymer. [191] The composition of the biodegradable plastic article therefore comprises, in addition to the biodegradable polymer, from 0.5% to 20% of enzymatic masterbatch.

[192] The methods for preparing these final articles are well known to those skilled in the art, including in particular the usual plastics processing techniques such as extrusion-inflation, extrusion-blowing, extrusion of cast film, calendering and thermoforming, injection molding, compression molding, rotomolding, coating, lamination, expansion, pultrusion, compression-granulation. Such operations are well known to those skilled in the art, who will easily adapt the conditions of the process according to the type of plastic articles planned (for example temperature, residence time, etc.).

[193] For the preparation of biodegradable plastic articles, the masterbatch can be mixed with the other constituents of the composition for their shaping. It is also possible to prepare a premix or “compound” comprising the masterbatch and at least the biodegradable polymer. This premix in solid form, in particular in the form of granules, can be stored then transported before being used for shaping the final article, alone or combined with other constituents depending on the final composition of the article. final.

[194] The present invention also relates to this pre-mixture or “compound”.

[195] Advantageously, the premix comprises:

60% to 98% biodegradable polymer,

0.1% to 20% support polymer,

0.01% to 8% enzymes,

0.01% to 5% animal and/or vegetable proteins,

0 to 5% polysaccharide and

0 to 35% mineral filler, the percentages being expressed by weight relative to the total weight of the composition of the pre-mixture.

[196] EXAMPLES

[197] I. Preparation of a mix of support polymer and enzyme

[198] The masterbatch is prepared from polycaprolactone (PCL) granules, proteins, a mineral filler (calcium carbonate, CaCOa) and enzymes in solution. The enzymatic composition was prepared from a commercial protease, Savinase® (Novozymes).

[199] The masterbatch was manufactured with a CLEXTRAL EVOLUM 25 HT co-rotating twin-screw comprising 11 zones for which the temperature is independently controlled and regulated. The extruder zones are heated according to table [1]. The enzymes in solution, the proteins, the calcium carbonate and possibly the gum arabic were introduced simultaneously at the start of the extruder (before zone 1) in order to produce the mixture according to an increasing temperature profile of between 25 and 50° vs. The enzymes in solution are introduced at 2.2 kg/h using a peristaltic pump. The proteins and possibly gum arabic are introduced at 1.8 kg/h using a doser specific to powders and the calcium carbonate is introduced at 2 kg/h. The PCL, also called support polymer, is introduced at 14kg/h in a partially or even completely molten state between zone 5 and zone 6 of the extruder at a temperature of 75°C.

[200] The granulation of each mixture is made with an underwater cut at the end of the extruder. The granules are dried at 45°C to 0.3% humidity.

[201] Master mix E is a comparative example and was prepared according to the same protocol described above but by replacing the proteins with gum arabic.

[202] [Table 1]: Temperature profile (°C) used for the preparation of the masterbatch.

[203] II. Commercial Products

[204] In these examples, milk protein isolates marketed under the references Euridiet 80 NS, GrassFit 80WPC by the company Eurial or IWPC 80 SH, IWPI 90 SH by the company Lactoland, gelatins of bovine origin are used. or porcine marketed under the references Stabicaps, Simogel and Emulsigel by the company Rousselot, rice proteins marketed under the references Brown rice protein powder by the company NP Nutra or Rice Protein R80+, H70+, H60+ by the company IIC Ingredients, proteins from peas marketed under the references Pea protein powder 80% by the company NP Nutra, or Pea Protein P80+, Fave bean protein, Chickpea protein and Mung bean protein by the company IIC Ingredients, gum arabic sold under the reference IntantGumAA by the company Nexira, polycaprolactone sold under the reference CAPA 6500 or CAPA6500D by the company Perstop, calcium carbonate sold under the reference OMYFILM 707-OG by the company Omya, PLA/PBAT mixtures marketed under the references Ecovio® F2331, Ecovio® F2223, Ecovio® F2332.

[205] III. Masterbatch compositions

[206] Masterbatches are prepared from different animal or vegetable proteins (with or without gum arabic). The compositions are described in Table 2. The support polymer is polycaprolactone (PCL).

[207] [Tables 1]: Composition of masterbatches

[208] Masterbatch A is a comparative example without the introduction of enzyme. Masterbatch E is a comparative example of the invention WO 2019/043134.

[209] IV. Production of single-layer films [210] For the preparation of single-layer films, a Labtech inflation extrusion line of type LF-250 is used with an extruder of type LBE20-10 30/C, diameter 20 mm and screw L/D = 30. Speed of the aim was between 50 and 60 rpm.

[211] The extrusion inflation temperatures are detailed in table 3.

[212] [Table 3]: Extrusion inflation temperatures for the films with mixtures A to J respectively.

[213] The films have an average thickness of 15 pm. The thicknesses were measured with a Positector electronic micrometer.

[214] V. Method of analysis

[215] The mechanical properties in traction can be measured using a Zwick or Lloyd type machine, equipped with a 50 N sensor or a 5 kN sensor. The properties are measured in two different directions: in the longitudinal direction and in the transverse direction. The tensile mechanical properties are measured according to EN ISO 527-3 standards. As for resistance to perforation, it is measured using a Dart-Test according to standard NE EN ISO 7765-1.

[216] The evaluation of the biodegradability of the films was evaluated with a depolymerization test carried out according to the following protocol: 100 mg of each sample were introduced into a plastic vial containing 50 mL of buffer solution at pH 8. Depolymerization is launched by incubating each sample at 45°C, in a shaken incubator at 150 RPM. An aliquot of ImL of buffer solution is taken regularly and filtered using a 0.2 µm filter syringe to be analyzed by high performance liquid chromatography (HPLC) with an Aminex HPX-87H column to measure the release. lactic acid (LA) and its dimer. The chromatography system used is a Nexan Series HPLC machine, SHIMADZU including a pump, an automatic sampler, a column thermostated at 50°C and a UV detector at 220nm. The eluent is a 5 mM H2SO4 solution. The injection is 20 pL of sample. Lactic acid is measured using standard curves prepared from commercial lactic acid. [217] The hydrolysis of plastic films is calculated from the lactic acid and the released lactic acid dimer. The percentage of depolymerization is calculated based on the percentage of PLA in the sample.

[218] VI. Composition of flexible monolayer films and results [219] The monolayer films were made from 95% of the same matrix,

Ecovio F2223 (30% PLA and 70% PBAT), and 5% of the masterbatches prepared in I and whose compositions are illustrated in Table 2. The thickness of these films is 15 pm.

[220] The evaluation of the biodegradability of the films was carried out according to the method described in V. The compositions of these different films as well as the depolymerization results at 45°C are presented in table 4. In this table, the example 5 with gum arabic, constitutes the comparative example.

[221] [Tables 4]: Depolymerization rate at 45°C after 7 days obtained for the different articles (flexible films).

[222] Flexible films 2 to 10, containing masterbatches B to J, meet the acceptability criteria. [223] The mechanical properties thus measured show that the films described in the invention have mechanical properties maintained and consistent with the field. The results are presented in Table 5.

[224] [Tables 5]: Characterization of the mechanical properties of the films

[225] For each protein or polysaccharide reference, the mechanical quantities measured are close. Films 4, 6, 7 have mechanical properties equivalent to those of the reference being film 5.

Claims

Claims

[Claim 1] Masterbatch comprising:

60 to 95% support polymer,

0.01 to 8% enzymes,

1 to 15% vegetable and/or animal proteins, and

0 to 10% mineral filler, the percentages being expressed by weight relative to the total weight of the composition of the masterbatch.

[Claim 2] Masterbatch according to claim 1, characterized in that the support polymer is chosen from polycaprolactone (PCL), polybutyene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PB AT) , polydioxanone (PDS), polyhydroxyalkanoate (PHA) and polylactic acid (PLA) and their mixtures, preferably the support polymer is PCL.

[Claim 3] Masterbatch according to any one of claims 1 or 2, characterized in that the content of support polymer is between 65 and 90% by weight relative to the total weight of the composition of the masterbatch.

[Claim 4] Masterbatch according to any one of claims 1 to 3, characterized in that the enzymes are chosen from enzymes capable of degrading polyesters, preferably the enzymes are chosen from depolymerases, esterases, lipases, cutinases, carboxylesterases, proteases and polyesterases.

[Claim 5] Masterbatch according to any one of claims 1 to 4, characterized in that the enzyme content is between 0.05 and 5% by weight relative to the total weight of the composition of the masterbatch.

[Claim 6] Masterbatch according to any one of claims 1 to 5, characterized in that the animal proteins come from animal sources chosen from meat, fish, dairy products and their mixtures.

[Claim 7] Masterbatch according to any one of claims 1 to 6, characterized in that the animal proteins are chosen from collagen, gelatin, milk proteins, and mixtures thereof, preferably the animal proteins are proteins of milk.

[Claim 8] Masterbatch according to any one of claims 1 to 6, characterized in that the vegetable proteins are chosen from pea proteins, bean proteins, soy proteins and rice proteins.

[Claim 9] Masterbatch according to any one of claims 1 to 8, characterized in that the mixture comprises animal proteins and vegetable proteins.

[Claim 10] Masterbatch according to any one of claims 1 to 7, characterized in that the masterbatch comprises only animal proteins.

[Claim 11] Masterbatch according to any one of claims 1 to 5 and 8, characterized in that the masterbatch comprises only vegetable proteins.

[Claim 12] Masterbatch according to any one of claims 1 to 11, characterized in that the animal and/or vegetable protein content is 3 to 9% by weight relative to the total weight of the composition of the masterbatch.

[Claim 13] Masterbatch according to any one of claims 1 to 12, characterized in that the masterbatch also comprises a polysaccharide.

[Claim 14] Masterbatch according to claim 13, characterized in that the polysaccharide is chosen from starch derivatives, natural gums, soluble soy polysaccharides, konjac, marine extracts and microbial or animal polysaccharides, or their mixture in all proportions, preferably the polysaccharide is gum arabic.

[Claim 15] Masterbatch according to any one of claims 1 to 14, characterized in that the masterbatch comprises a mineral filler, preferably calcium carbonate.

[Claim 16] Use of a masterbatch according to any one of claims 1 to 15 in the manufacture of biodegradable plastic articles.

[Claim 17] Process for preparing a masterbatch defined in any one of claims 1 to 15, characterized in that it comprises the steps of mixing enzymes, animal and/or plant proteins and the support polymer in a mixer at a mixing temperature Tb, and recovery of the masterbatch.

[Claim 18] Method according to claim 17, characterized in that the mixing temperature Tb is between 40 and 200 °C, preferably between 55 and 175 °C.

[Claim 19] Method according to one of claims 17 or 18, characterized in that the mixer is an extruder.

[Claim 20] Method according to any one of claims 17 to 19, characterized in that the polysaccharide and the animal and/or vegetable proteins are added to the masterbatch in the form of a mixture.

[Claim 21] Article of biodegradable plastic material comprising the masterbatch defined in any one of claims 1 to 15.

[Claim 22] Article according to claim 21 further comprising a polymer, characterized in that the enzymes of the masterbatch degrade the polymer. |