Method for preparing enzyme master batch

Abstract

The present invention relates to a method for preparing a masterbatch comprising a polysaccharide, an enzyme and a low melting polymer in a mixer, in particular for use in the manufacture of articles made from biodegradable plastic materials.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to a method for preparing a masterbatch comprising a polysaccharide, an enzyme and a low melting polymer in a mixer, in particular for use in the manufacture of articles made from biodegradable plastic materials. [Background technology]

[0002] To address ecological challenges, methods have been developed for preparing plastic materials based on biodegradable and bio-origin polyesters. These plastic products, synthesized from starch or starch derivatives and polyesters, are used to manufacture articles with a short life span, such as plastic bags, food packaging materials, bottles, packaging films, etc.

[0003] Typically, these plastic compositions include polyesters and powders derived from various cereals (U.S. Pat. Nos. 5,739,244; 6,176,915; U.S. Patent Application Publication No. 2004 / 0167247; WO 2004 / 113433; French Patent Application Publication Nos. FR2903042; FR2856405).

[0004] In order to control the degradation of these plastic products, it has been proposed to add one or more mineral fillers (WO 2010 / 041063) and / or biological substances with polyester degrading activity (WO 2013 / 093355; WO 2016 / 198652; WO 2016 / 198650 / WO 2016 / 146540; WO 2016 / 062695).

[0005] Thus, biodegradable plastic articles that contain biological materials, more particularly enzymes, dispersed in a polymer have better biodegradability compared to plastic products that do not contain these enzymes.

[0006] Methods for preparing these enzyme plastics have been reported previously, however, problems related to homogeneity and roughness may appear, which may affect the physical properties of the product. For example, the presence of enzyme aggregates leads to greater roughness, reducing the aesthetics of the product and modifying its physical and mechanical properties.

[0007] The first improvements were made by adding the enzyme pre-mixed with the polysaccharide and solvent as a single liquid formulation to the support polymer (WO 2019 / 043145, WO 2019 / 043134).

[0008] The aim of the present invention is in particular to simplify the tools required for the industrial implementation of the masterbatch preparation process and at the same time to facilitate and ensure its implementation by preserving, and possibly improving, the preservation of the activity of the enzymes after formulation and their performance in terms of their ability to be used in the preparation of final articles.

[0009] The present invention describes a method for the preparation of masterbatches which, when used in the manufacture of plastic products containing enzymes dispersed in the polymer, allows for the dispersion of the enzyme in the final composite as well as an improved level of biodegradability of the plastic material. Summary of the Invention

[0010] The present invention relates to a method for preparing a masterbatch comprising a polysaccharide, an enzyme and a support polymer in a mixer, the method comprising the steps of: a) separately and simultaneously introducing a1) an enzyme in solution, a2) a polysaccharide, and a3) a support polymer; b) mixing the support polymer at a temperature at which the support polymer is partially or completely melted; and c) recovering the masterbatch.

[0011] The invention also relates to the masterbatch thus obtained and to a plastic article obtainable by mixing the masterbatch with a polymer capable of being degraded by the enzyme of the masterbatch, or with a polymer mixture containing such a polymer.

[0012] In particular, the present invention relates to a method for the preparation of a plastic article comprising an enzymatically degradable polymer and an enzyme capable of degrading said polymer, comprising the step of mixing a masterbatch according to the invention with said polymer, alone or as a mixture. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention relates to a method for preparing a masterbatch comprising a polysaccharide, an enzyme capable of degrading a polyester and a support polymer in a mixer, said method comprising the steps of: a) separately and simultaneously introducing a liquid formulation of an enzyme, a polysaccharide and a support polymer; b) and mixing them at a temperature at which the support polymer is partially or completely melted; and c) recovering the masterbatch. Unless otherwise indicated, percentages are given by weight relative to the total weight of the composition to which reference is made.

[0014] As used herein, the term "polysaccharide" refers to a molecule composed of long chains of monosaccharide units linked together by glycosidic bonds. The structure of a polysaccharide can range from linear to highly branched. Examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin. Polysaccharides include natural polysaccharides or polysaccharides that have been chemically modified by crosslinking, oxidation, acetylation, partial hydrolysis, etc.

[0015] Carbohydrate polymers can be classified according to their origin (marine, plant, microbial or animal), structure (linear, branched) and / or physical behavior (e.g., designation as gums or hydrocolloids, which refers to the tendency of these polysaccharide hydrates in hot or cold water to form viscous solutions or dispersions at low gum or hydrocolloid concentrations).

[0016] In the present invention, the polysaccharides are classified according to the following classification: starch and derivatives, such as amylose, amylopectin, maltodextrin, glucose syrup, dextrin and cyclodextrin; cellulose and derivatives, such as methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, etc. - plant exudates and extracts, also known as vegetable gums or natural gums, including, but not limited to, gum arabic (or gum acacia), gum tragacanth, guar gum, locust bean gum, karaya gum, mesquite gum, galactomannans, pectins, soluble soy polysaccharides; marine extracts, such as carrageenans and alginates, - microbial and animal polysaccharides, such as gellan, dextran and chitosan, They can be classified according to:

[0017] Polysaccharides can be classified according to their solubility in water. In particular, cellulose is not soluble in water. In the present invention, polysaccharides have the ability to be soluble in water.

[0018] The polysaccharides used in the formulation of the plastic composition are well known to those skilled in the art. In particular, they are chosen from starch derivatives such as amylose, amylopectin, maltodextrin, glucose syrup, dextrin and cyclodextrin, natural gums such as gum arabic, gum tragacanth, guar gum, locust bean gum, gum karaya, mesquite gum, galactomannan, pectin or soluble soy polysaccharides, marine extracts such as carrageenans and alginates, and microbial or animal polysaccharides such as gellan, dextran, xanthan or chitosan, and mixtures thereof. The polysaccharide may also be a mixture of several of the polysaccharides mentioned above. In a preferred embodiment, the polysaccharide used is a natural gum, more particularly gum arabic.

[0019] The enzymes used are enzymes that have polyester degrading activity, therefore their incorporation into products made from biodegradable polyester-based plastics improves the biodegradability of these products.

[0020] Examples of enzymes with polyesterolytic activity are well known to those skilled in the art and are in particular depolymerases, esterases, lipases, cutinases, carboxylesterases, proteases or polyesterases.

[0021] In particular, mention is made of enzymes capable of degrading polyesters to improve the biodegradability of articles prepared with masterbatches according to the invention.In a particular embodiment of the invention, the enzyme is capable of degrading PLA.Such enzymes and the methods of incorporating them into thermoplastic articles are known to those skilled in the art and are described in particular in WO 2013 / 093355, WO 2016 / 198652, WO 2016 / 198650, WO 2016 / 146540 and WO 2016 / 062695.

[0022] In particular, the enzymes used in the context of the present invention are selected from proteases and serine proteases. Examples of serine proteases include proteinase K from Tritirachium albumen, or PLA degrading enzymes from Amycolatopsis sp., Actinomadura keratinilytica, Laceyella sacchari LP175, Thermus sp., or Bacillus licheniformis, or new forms of commercially available enzymes known to be PLA degrading, such as Savinase®, Esperase®, Everlase®, or any enzyme from the family of subtilisin CAS [9014-01-1], or any functional variant.

[0023] The enzymes are used in their pure or concentrated form, optionally mixed with one or more excipients.

[0024] In particular, the enzyme is selected so as to be capable of degrading at least one polymer of the plastic article obtained in the manufacturing process of which the masterbatch is used.

[0025] The enzyme is used in the method according to the invention in the form of a liquid solution. The liquid formulation according to the invention is an enzyme solution and / or a suspension of the enzyme in a solvent, in particular a thick suspension that is flowable at room temperature. The liquid formulation must be in a form suitable for introduction into the mixer by any conventional means for introducing liquid formulations into the mixer. Thus, the formulation may be introduced via a syringe or a peristaltic pump. The skilled person should be able to determine which device is most suitable for adding the formulation. In a preferred embodiment, the liquid formulation is introduced via a peristaltic pump. The solvent is a solvent that does not degrade the enzyme, more particularly water. In an embodiment of the invention, the liquid formulation consists essentially of the enzyme and a solvent, in particular water.

[0026] In particular, the form of the formulation depends on the enzyme content, it being understood that if the enzyme content exceeds their solubility threshold in the solvent, the formulation will contain the enzymes in suspension and appear to be a thick composition, but still be flowable. In an advantageous embodiment of the invention, the liquid enzyme formulation is an enzyme solution.

[0027] In one embodiment the liquid enzyme formulation comprises 0.01-70% by weight of enzyme, in particular 0.3-60% by weight of enzyme, more particularly 0.5-35% by weight of enzyme. In particular the enzyme formulation, in particular the enzyme solution, may comprise an enzyme content of 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35% or more by weight.

[0028] The support polymer is a low melting point polymer, advantageously one having a melting point below 140° C. and / or a glass transition temperature below 70° C. It must also be compatible with the polymer or polymers that are mixed together in the masterbatch for the preparation of the enzyme-plastic article.

[0029] Such support polymers are well known to those skilled in the art. In particular, they consist of polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polydioxanone (PDS), polyhydroxyalkanoate (PHA), polylactic acid (PLA), or copolymers thereof. They may also consist of natural conjugate molecules such as starch or polymers described as versatile, in other words compatible with a wide range of polymers such as EVA type copolymers.

[0030] Advantageously, the support polymer has a melting point below 120°C and / or a glass transition temperature below 30°C. Generally, the support polymer is a single polymer as defined above. It may consist of a mixture of these support polymers. In a particular embodiment of the invention, the support polymer is PCL. In certain embodiments of the present invention, the enzymes of the masterbatch are not capable of degrading the support polymer.

[0031] Step a) corresponds to the addition of the polysaccharide, the enzyme in the liquid formulation and the support polymer in the mixer. The polysaccharide is in powder form and is introduced into the mixer using a metering device specific for powders. The enzyme in the liquid formulation is added by any common means for introducing a solution into a mixer or any other industrial means such as a peristaltic pump or a syringe. In one embodiment, the enzyme in the liquid formulation is added via a peristaltic pump. The support polymer is in the form of granules and is introduced into the mixer via a metering device specific for granules.

[0032] In a particular embodiment, the masterbatch is prepared by mixing: - 60 to 90% of the support polymer, in particular PCL, - 10 to 20% liquid enzyme preparations, in particular enzyme solutions, -2-15% polysaccharides, especially gum arabic.

[0033] In a particular embodiment of the invention, the masterbatch comprises an enzyme having a polyester degrading activity of up to 5%. The content of the liquid enzyme formulation, in particular the enzyme solution, used to prepare the masterbatch therefore depends on the enzyme content in the liquid formulation.

[0034] Advantageously, the liquid enzyme blend / polysaccharide ratio is calculated to have between 30% and 70% of the dry mass (enzyme and polysaccharide) of both mixtures.

[0035] The polysaccharide / enzyme solution ratio is determined to have a dry weight of at least 30%, up to 55%, and in some cases up to 70%.

[0036] The skilled person knows how to adapt the process characteristics (temperature and time) required to carry out step a) depending on the components used (polysaccharide, enzyme and support polymer).

[0037] The mixing in step b) is carried out at a temperature at which the support polymer is partially or completely melted. It should be understood that the temperature of step b) is determined by the skilled person so as not to modify the enzymes, more particularly so as not to substantially reduce their support polymer degrading enzyme activity. In a particular embodiment, the temperature of step b) is a temperature below the melting point (Tm) of the support polymer. The skilled person can select the support polymer according to its melting point and the ability of the enzyme selected in the method according to the present invention to withstand this temperature. In a particular embodiment, the temperature of step b) is comprised between the glass transition temperature (Tg) and the melting point (Tm) of the support polymer. Alternatively, the temperature of step b) is set to a temperature above the Tm of the support polymer.

[0038] Generally, the temperature of step b) may be comprised between 40 and 200°C. In one embodiment, the temperature is higher than 40°C or higher than 50°C. Preferably, the temperature is comprised between 55°C and 175°C. In a preferred embodiment, the temperature of step b) is adjusted according to the nature of the polymer used. The temperature of step b) is therefore the melting point of the polymer used or usually corresponds to its melting point. Typically, the temperature does not exceed 300°C, more particularly, the temperature does not exceed 250°C. In step b), it is desirable to keep the temperature of the mixture as low as possible to allow mixing and homogeneous dispersion of the enzyme and polysaccharide in the support polymer. In a particular embodiment, the support polymer is PCL and the mixing temperature in step b) is about 60°C, 55-65°C.

[0039] In step b), the mixing of the polysaccharide, the enzyme and the support polymeric component lasts for 10 to 35 seconds, in particular for 15 to 35 seconds, in particular for about 20 seconds, about 25 seconds or about 30 seconds.

[0040] Throughout the process of making the masterbatch, the temperature is gradually increased to ensure a homogeneous and consistent mixture while preserving the characteristics and properties of each component.

[0041] The residence time of the polysaccharide / enzyme composition in the polymer at temperatures above 100° C. in the mixer (steps b) and c)) is advantageously as short as possible. Preferably, the residence time is comprised between 5 seconds and 10 minutes. However, a residence time of less than 5 minutes is preferred. In a preferred embodiment, the latter is less than 3 minutes, and in some cases less than 2 minutes.

[0042] The masterbatch obtained in step c) is in solid form. It is advantageous to recover it in the form of granules. These granules can be stored, transported and incorporated in the manufacture of plastic products or articles, which may be called "final products", regardless of their shape and their use. They may consist of films, or flexible or solid parts, with shapes and volumes suitable for their use.

[0043] The masterbatch formulation may include a mineral filler, in which case the mineral complex is introduced during step a) and the polysaccharide is added in the mixer together with the liquid enzyme formulation and the support polymer.

[0044] Many minerals may be used. Examples include calcites, carbonates or metal carbonates such as calcium carbonate, potassium carbonate, magnesium carbonate, aluminum carbonate, zinc carbonate, copper carbonate, chalk, dolomite, etc.; silicates such as calcium silicate, potassium silicate, magnesium silicate, aluminum silicate, or mixtures thereof, for example mica, smectites such as montmorillonite, vermiculite, and sepiolite-palygorskite; sulfates such as barium sulfate or calcium sulfate (gypsum), mica; hydroxide salts or metal hydroxides such as calcium hydroxide, potassium hydroxide (lye), magnesium hydroxide, aluminum hydroxide, sodium hydroxide (caustic soda), hydrotalcite, etc.; metal oxides 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.

[0045] In a preferred embodiment, the mineral filler used is calcium carbonate. Generally, masterbatches are formulated with: - 60 to 90% of the support polymer, in particular PCL, - 10 to 20% liquid enzyme preparations, in particular enzyme solutions, - 2 to 15% polysaccharides, especially gum arabic, and -0-20% fillers, especially calcium carbonate.

[0046] The masterbatch may also include the presence of one or more compounds. In particular, the masterbatch may include one or more additives. In general, additives are used to improve certain properties of the final product. For example, additives may be selected from plasticizers, colorants, processing aids, rheological agents, antistatic agents, anti-UV agents, toughening agents, compatibilizers, flame retardants, antioxidants, pro-oxidants, light stabilizers, oxygen scavengers, adhesives, products, excipients, and the like.

[0047] Advantageously, the masterbatch comprises less than 20% by weight of additive, preferably less than 10% by weight of additive, relative to the total weight of the masterbatch. Generally, the composition of the masterbatch comprises between 0% and 10% by weight of additive, relative to the total weight of the masterbatch.

[0048] The composition of the masterbatch after compounding comprises between 5% and 30% by weight of the liquid enzyme formulation as defined above, relative to the total weight of the masterbatch. In one embodiment, the enzyme formulation represents between 8% and 22% by weight, relative to the total weight of the composition. In a preferred embodiment, the masterbatch comprises between 10% and 20% by weight of the enzyme formulation of its composition.

[0049] The process for the preparation of the masterbatches is carried out in a mixer. The person skilled in the art is aware of the different types of mixers that can be used for the preparation of these polymeric masterbatches. In a preferred embodiment, the mixer is an extruder. It may be of the single screw or twin screw type. Preferably, it is of the twin screw type.

[0050] In particular, the method is carried out in an extruder comprising at least three zones, a head zone where the first component is inserted, a mixing zone, and an exit zone through which the masterbatch is withdrawn, by the following steps a) to c): a) separately and simultaneously introducing into the head region a polysaccharide and enzyme blend and, where appropriate, a mineral filler as defined above, b) mixing the components in a mixing zone at a temperature at which the support polymer is partially or completely melted; c) Recovering the masterbatch at the exit of the extruder.

[0051] A person skilled in the art will know how to adapt the characteristics of the extruder (i.e., length and diameter of one or more screw sections, degassing zones, etc.) and the residence times of the polysaccharide, enzyme and support polymer according to the time and temperature constraints of the different steps of the method of the invention.

[0052] In particular, the temperature of the head region is below the melting point of the support polymer and the temperature of the mixing region is higher than the head region, in particular as defined above for the mixing temperature.

[0053] The mixing region itself comprises several regions, and the skilled person can adapt the temperature of each region as required, in particular depending on the enzyme and support polymer used.

[0054] The masterbatches may be obtained in the form of granules prepared by conventional techniques, which may be stored, transported and used in the manufacture of articles made from the biodegradable plastic material, which may be called "final articles".

[0055] When it is in the form of granules, the masterbatch can be dried for its storage. The drying methods are the usual methods known to those skilled in the art, in particular by hot air oven, vacuum oven, desiccator, microwave or fluidized bed. The drying temperature and time depend on the one hand on the water content brought about by the enzyme solution in the preparation of the masterbatch, but also on the melting temperature and glass transition temperature of the support polymer used. Once dried, the composition of the masterbatch advantageously comprises: -60% to 95% support polymer. -0.5% to 7% enzymes, -2% to 27% polysaccharides, and -0%~30% mineral filler.

[0056] Generally, the moisture content is less than 0.5%, preferably less than 0.3%.

[0057] The resulting masterbatches in the form of granules can then be used to manufacture biodegradable plastic products or "final articles". These can consist of films, or flexible or solid parts with shapes and volumes suitable for their use.

[0058] The biodegradable plastic article is obtained by mixing a masterbatch containing an enzyme with at least one polymer that can be degraded by said enzyme.

[0059] The present invention therefore relates to a method for preparing an article made from a plastic material or a premix as defined below, comprising an enzymatically degradable polymer and an enzyme capable of degrading said polymer, comprising the steps of preparing a masterbatch comprising an enzyme capable of degrading said polymer, a polysaccharide and a support polymer, and optionally a mineral filler, said masterbatch being subjected to the following steps: a) separately and simultaneously introducing into a mixer the enzyme, the polysaccharide and the support polymer as a liquid blend, and optionally the mineral filler as defined above, b) mixing the ingredients; and c) recovering the masterbatch; and thereafter mixing said enzymatically degradable polymer with a masterbatch.

[0060] Advantageously, said enzymatically degradable polymers are biodegradable polyesters, which are well known to those skilled in the art and are, for example, polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoates (PHA), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), plasticized starch, and mixtures thereof.

[0061] These polyesters are chosen for their physicochemical properties and for the properties sought by the final article, in particular their mechanical properties, but also for their colour and their transparency.

[0062] The biodegradable polyester used in the preparation of the final article may have the same or different physicochemical properties as the polyester used as the support polymer in the masterbatch according to the invention.

[0063] In a preferred embodiment, the enzymatically degradable polyester comprises PLA, either alone or in a mixture with another of the above mentioned polyesters, in particular as a PLA / PBAT mixture.

[0064] Thus, the biodegradable plastic article consists of the masterbatch and the biodegradable polymer.

[0065] In addition to the biodegradable polymer, the composition of the biodegradable plastic article includes 0.5% to 20% of an enzyme masterbatch.

[0066] The methods for preparing these final articles are well known to those skilled in the art and include, in particular, the usual plastic techniques such as blown film extrusion, extrusion blow molding, cast film extrusion, calendering and thermoforming, injection molding, compression molding, rotational molding, coating, layering, foam molding, pultrusion and compression granulation. Such operations are well known to those skilled in the art, who will easily adapt the process conditions (e.g., temperature, residence time, etc.) according to the type of plastic article under consideration.

[0067] In the case of preparing a biodegradable plastic article, the masterbatch can be mixed with other components of the composition for its molding. It is also possible to prepare a premix or "composite" that contains the masterbatch and at least the biodegradable polymer. This premix in solid form, in particular in granular form, can be stored and then, after transportation, can be used to form the final article, either alone or in combination with other components, according to the final composition of the final article. Advantageously, the premix comprises: - 8% to 99% by weight of a biodegradable polymer, preferably PLA, - 0.01% to 5% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.1% to 20% by weight of a support polymer as defined above, in particular PCL, and - 0.01% to 2% by weight of an enzyme having a biodegradable polymer degrading activity, more particularly having a PLA degrading activity, and, where appropriate, -0% to 35% by weight of mineral fillers.

[0068] The final articles may consist of films, flexible or solid parts with shapes and volumes suitable for their use. Examples of biodegradable plastic articles relevant to the present invention include films, mulching films, packaging films, food or non-food films; packaging materials such as packaging blisters, trays, etc.; disposable tableware such as cups, plates or dinnerware; stoppers and lids; beverage capsules; and horticultural articles.

[0069] Advantageously, the composition of the plastic article is as follows: - 60% to 98% by weight of a polymer or a mixture of biodegradable polymers, - 0.01% to 5% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.01% by weight to 20% by weight of a support polymer as defined above, - 0.01% to 2% by weight of an enzyme having biodegradable polymer degrading activity, - 0% to 35% by weight of mineral fillers, -0% to 5% by weight of additives.

[0070] The biodegradable plastic articles obtained with the enzyme masterbatch can be flexible and / or rigid.

[0071] In the case of flexible articles, the enzymatically degradable polyester comprises PLA. In one embodiment, the biodegradable polyester is a PBAT / PLA mixture, the weight ratio of which is preferably in the range of 10 / 90 to 20 / 80, more preferably 13 / 87 to 15 / 85.

[0072] In another embodiment, the biodegradable polyester is a PBAT / PLA mixture, the weight ratio of which ranges from 10 / 90 to 30 / 70, 10 / 90 to 40 / 60, 10 / 90 to 50 / 50, 10 / 90 to 60 / 40, 10 / 90 to 70 / 30, 10 / 90 to 80 / 20, 10 / 90 to 90 / 10.

[0073] In another embodiment, the biodegradable polyester is a PBAT / PLA blend, the weight ratio of which is less than 10 / 90, 9 / 91 or less, 8 / 92 or less, 7 / 93 or less, 6 / 94 or less, 5 / 95 or less, 4 / 96 or less, 3 / 97 or less, 2 / 98 or less, 1 / 99 or less.

[0074] In another embodiment, the biodegradable polyester is PLA.

[0075] The flexible biodegradable plastic article is characterized by a thickness of less than 250 μm, preferably less than 200 μm. In a preferred embodiment, the film has a thickness of less than 100 μm, more advantageously less than 50 μm, 40 μm or 30 μm, preferably between 10 and 20 μm. More preferably, the thickness of the flexible article is 15 μm. Examples include films and bags such as food films, packaging films, industrial films or mulching films. Advantageously, the composition of the flexible article comprises: - 70% to 98% by weight of a polymer or a mixture of biodegradable polymers, - 0.01% to 5% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.1% to 20% by weight of a support polymer as defined above, and - 0.01% to 2% by weight of an enzyme having biodegradable polymer degrading activity, 0% to 5% by weight, in particular 0.01% to 5% by weight, in particular 0.05% to 5% by weight, of mineral fillers, -0% to 5% by weight of additives.

[0076] The composition according to the invention is particularly suitable for producing plastic films.The film according to the invention can be produced by conventional technical methods, in particular blown film extrusion.The film is prepared from granules with the composition according to the invention, which are dissolved by conventional techniques, in particular extrusion.

[0077] The film with the previously defined composition containing enzymes can be composed of a monolayer or multilayer film. In the case of a multilayer film, at least one of the layers has the previously defined composition. The monolayer and multilayer films with the previously defined composition have a high PLA content and retain the mechanical properties that are desirable, especially for the preparation of biodegradable and bio-origin films for food and non-food packaging. For this purpose, the components of the composition according to the invention are preferably selected from products that are compatible with use in food.

[0078] The multilayer film may be a film comprising at least three phases of the ABA, ABCA or ACBCA type, with layers A, B and C having different compositions. In a preferred embodiment, the multilayer film is of the ABA or ACBCA type.

[0079] Generally, layers A and B advantageously comprise the composition according to the invention, PLA and / or polyester. Layer C, if present, is present to impart specific properties to the article according to the invention, more particularly to impart gas, and in particular oxygen, barrier properties. Such barrier materials are well known to the person skilled in the art and are in particular PVOH (polyvinyl alcohol), PVCD (polyvinyl chloride), PGA (polyglycolic acid), cellulose and its derivatives, milk proteins or polysaccharides and mixtures thereof and mixtures of these in all proportions.

[0080] In the case of multilayer films as defined above, in particular in the case of films of the ABA, ABCA or ACBCA type, the enzyme is present in all layers or in only one layer, for example in layers A and B or only in layer A or layer B.

[0081] In a particular embodiment of the invention, the two layers A consist of the composition of the invention comprising PLA, polyester and polypropylene glycol diglycidyl ether (PPGDGE), without enzymes, and the enzyme is present in layer B, the composition of the invention comprising enzymes as defined above, or in a particular composition, in particular an enzyme composition in a low melting polymer as defined above.

[0082] In some embodiments, the composition of the enzyme layer of the flexible article (single or multi-enzyme layer) may comprise up to 95% by weight of a biodegradable polymer, preferably PLA. Thus, the enzyme layer may comprise 8% to 50%, 8% to 60%, 8% to 70%, 8% to 80%, or 8% to 90% by weight of a biodegradable polymer.

[0083] Advantageously, the composition of the enzyme layer of the (single-phase or multi-layer) flexible article comprises: 8% to 95% by weight, in particular 8% to 70% by weight, 8% to 60% by weight, 8% to 50% by weight or 8% to 40% by weight of a biodegradable polymer, preferably PLA, - 0.02% to 4% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.1% to 19% by weight of a support polymer as defined above, and - 0.05% to 2% by weight of an enzyme having a biodegradable polymer degrading activity, more particularly having a PLA degrading activity, and, where appropriate, 0% to 5% by weight, in particular 0.01% to 5% by weight, in particular 0.05% to 5% by weight, of mineral fillers.

[0084] For rigid articles, the biodegradable polyester is PLA, preferably a PLA / calcium carbonate mixture, the weight ratio of which is in the range of 100 / 0 to 25 / 75, preferably 95 / 5 to 45 / 55, more preferably 90 / 10 to 50 / 50. In another embodiment, the biodegradable polyester is a PBAT / PLA mixture, the weight ratio of which is in the range of 10 / 90 to 80 / 20, more preferably 20 / 80 to 60 / 40.

[0085] The rigid article has a thickness comprised between 200 μm and 5 mm, between 150 μm and 5 mm, preferably between 200 μm and 3 mm, or between 150 μm and 3 mm. In one embodiment, the article has a thickness comprised between 200 μm and 1 mm, between 150 μm and 1 mm, preferably between 200 μm and 750 μm, or between 150 μm and 750 μm. In another embodiment, the thickness is 450 μm.

[0086] Examples of such biodegradable plastic articles include cups, plates, cutlery, trays, drink capsules and packaging blisters, more generally packaging materials for food, cosmetics or garden products.

[0087] Advantageously, the composition of the rigid article comprises: - 60% to 95% by weight of a polymer or a mixture of biodegradable polymers, - 0.01% to 5% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.1% by weight to 20% by weight of a support polymer as defined above, - 0.01% to 2% by weight of an enzyme having biodegradable polymer degrading activity, 0% to 35% by weight, in particular 0.01% to 35% by weight, of mineral fillers, -0% to 5% by weight of additives.

[0088] In another embodiment, the composition of the rigid article comprises: -60% to 80% by weight of a polymer or a mixture of biodegradable polymers, - 0.01% to 5% by weight of a polysaccharide, preferably a natural gum such as gum arabic, - 0.1% to 20% by weight of a support polymer as defined above, and - 0.01% to 2% by weight of an enzyme having biodegradable polymer degrading activity, - 8% to 35% by weight of mineral fillers, -0% to 5% by weight of additives.

[0089] Thus, the composition of the rigid article comprises greater than 60% by weight, or greater than 70% by weight, or greater than 80% by weight, or greater than 90% by weight of a biodegradable polymer or mixture of polymers.

[0090] The mineral filler content in the rigid article is comprised between 0.01% and 35% by weight, depending on the nature of the mineral filler.

[0091] In some embodiments, the rigid article thus comprises greater than 0.01 wt.%, greater than 0.1 wt.%, greater than 1 wt.%, or greater than 2 wt.%, or greater than 3 wt.% mineral filler.

[0092] In other embodiments, the amount by weight of mineral filler is 4% or more, 5% or more, 6% or more, 7% or more, or 8% or more.

[0093] In still other embodiments, the mineral filler in the rigid article is between 10% and 35%, between 15% and 30%, or between 20% and 28% by weight.

[0094] The final article, whether flexible or rigid, may also include plasticizers, compatibilizers and other common additives included in the composition of plastic materials, such as pigments or dyes, release agents, impact modifiers, antiblocking agents, and the like.

[0095] Examples of plasticizers include citrate esters and lactic acid oligomers (LAO). Citrate esters are plasticizers known to those skilled in the art, particularly as bio-origin materials. In particular, triethyl citrate (TEC), acetyl triethyl citrate (TEAC), tributyl citrate (TBC) and acetyl tributyl citrate (TBAC). Preferably, the citrate ester used as plasticizer in the composition according to the invention is TBAC.

[0096] LAOs are also plasticizers known to those skilled in the art, in particular as biomaterials. They consist of lactic acid oligomers with a molecular weight of less than 1,500 g / mol. Preferably, they are esters of lactic acid oligomers, the carboxylic acid ends of which are blocked by esterification with alcohols, in particular C1-C10 linear or branched alcohols, advantageously C6-C10 alcohols, or mixtures thereof. Mention may be made in particular of the LAOs described together with their preparation in patent application EP2256149, and of the LAOs sold under the trademark Glyplast® by Condensia Quimica, in particular the references Glyplast® OLA 2, with a molecular weight of 500-600 g / mol, and Glyplast® OLA 8, with a molecular weight of 1,000-1,100 g / mol. In a preferred embodiment of the invention, the LAO has a molecular weight of at least 900 g / mol, preferably from 1,000 to 1,400 g / mol, more preferably from 1,000 to 1,100 g / mol.

[0097] Poly(propylene glycol) diglycidyl ethers, also called glycidyl ethers, are specifically referred to as "reactive plasticizers" in WO 2013 / 104743 and are used in the preparation of block copolymers with PLA and PBAT. They are also identified as liquid epoxy resins by DOW and sold under the reference "DER™ 732P" or as aliphatic epoxy resins by HEXION under the reference "Epikote™ Resin 877".

[0098] Optionally, the composition according to the invention may contain other PLA / polyester compatibilizers in conjunction with the PPGDGE. Such PLA / polyester compatibilizers are well known to those skilled in the art and are chosen in particular from polyacrylates, ethylene terpolymers, acrylic esters and glycidyl methacrylate (for example sold under the trademark Lotader® by the company Arkema), triblock copolymers PLA-PBAT-PLA, PLA grafted with maleic anhydride (PLA-g-AM) or PBAT grafted with maleic anhydride (PBAT-g-AM), in particular poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate), as described by Dong & al. (International Journal of Molecular Sciences, 2013, 14, 20189-20203) and Ojijo & al. (Polymer 2015, 80, 1-17), more particularly the ADR 4468 grade sold under the name JONCRYL® by the company BASF.

[0099] Working Example Example 1: Use of the masterbatch in flexible articles I. Preparation of the Support Polymer and Enzyme Mixture 1. Preparation of master batches under prior art conditions The support polymer and enzyme mixture A1 is prepared from granules of polycaprolactone (PCL), polysaccharide (gum arabic), mineral filler (calcium carbonate, CaCO3) and enzyme in solution. The support polymer and enzyme mixture is produced in a co-rotating twin-screw extruder Clextral Evolum 25 HT equipped with 11 zones in which the temperature is independently monitored and regulated. The enzyme in solution, gum arabic and calcium carbonate are introduced simultaneously at the inlet of the extruder in order to carry out the mixing according to an increasing temperature profile including between 25 ° C and 50 ° C. The enzyme in solution is introduced at 2.6 kg / h using a peristaltic pump. Then, gum arabic at 1.4 kg / h and calcium carbonate at 2 kg / h are introduced using metering machines specific for powders. PCL, also called support polymer, is introduced at 14 kg / h, partially or completely molten state, at a temperature of 75 ° C, between zones 5 and 6 of the extruder.

[0100] Mixture A2 is made on a different day and under the same conditions as mixture A1. The support polymer and enzyme mixture A3 is prepared from granules of polycaprolactone (PCL), polysaccharide (gum arabic), mineral filler (calcium carbonate, CaCO3) and enzyme in solution. The support polymer and enzyme mixture was produced in a co-rotating twin-screw extruder Clextral Evolum 25 HT equipped with 11 zones that monitor and regulate the temperature independently. The enzyme in solution, gum arabic and calcium carbonate were introduced simultaneously at the inlet of the extruder to carry out according to a temperature profile that gradually increases between 25 ° C and 50 ° C. The enzyme in solution is introduced at 2.2 kg / h using a peristaltic pump. Then, gum arabic is introduced at 1.8 kg / h and calcium carbonate at 2 kg / h using a metering machine specific for powders. PCL, also called support polymer, is introduced at 14 kg / h, in a partially or completely molten state, at a temperature of 75 ° C, between zones 5 and 6 of the extruder.

[0101] Granulation of each mixture is carried out by underwater cutting. The granules are dried at 45° C. to a moisture content of 0.3%.

[0102] 2. Preparation of master batches by the method of the present invention A support polymer and enzyme mixture B1 is prepared according to the method of the invention from granules of polycaprolactone (PCL), a polysaccharide (gum arabic) and enzyme in solution.

[0103] The support polymer and enzyme mixture are produced in a co-rotating twin-screw extruder CLEXTRAL EV25HT with 11 zones in which the temperature is independently monitored and regulated according to an increasingly increasing temperature profile ranging from 25°C to 50°C. The PCL, the enzymes in solution and gum arabic are introduced separately and simultaneously into the head of the twin screws. The PCL is introduced at 16 kg / h, the enzymes in solution at 2.2 kg / h using a peristaltic pump and the gum arabic at 1.8 kg / h using a metering device specific for powders. Mixture B2 is made on a different day and under the same conditions as mixture B1.

[0104] A support polymer and enzyme mixture B3 is prepared according to the method of the invention from granules of polycaprolactone (PCL), polysaccharide (gum arabic), mineral filler (calcium carbonate, CaCO3) and enzyme in solution.

[0105] The support polymer and enzyme mixture is produced in a co-rotating twin-screw extruder CLEXTRAL EV25HT with 11 zones in which the temperature is independently monitored and regulated according to an increasing temperature profile ranging from 25°C to 60°C. PCL, enzymes in solution, gum arabic and calcium carbonate are introduced separately and simultaneously into the head of the twin screws. PCL is introduced at 14 kg / h, enzymes in solution at 2.2 kg / h using a peristaltic pump, gum arabic at 1.8 kg / h using a powder-specific metering device and calcium carbonate at 2 kg / h.

[0106] II. Commercially available products In these examples, PCL sold under the reference Capa™ 6500 by the company Perstorp, calcium carbonate sold under the reference OMYAFILM 707-OG by the company Omya, and gum arabic sold under the reference InstantGum AA by the company Nexira are used. A PLA / PBAT mixture sold by the company BASF under the reference ECOVIO F2223 was used.

[0107] III. Production of the film For the blown film extrusion, a lab bench Labtech LF-250 equipped with a LBE20-30 / C type 30L / D screw, width 20 mm was used. The screw speed was 50-60 rpm, and the high and low extrusion speeds were 4.3-5.7 m / min. The blown film extrusion temperatures are detailed in Tables 1a, 1b and 1c. [Table 1] [Table 2] [Table 3]

[0108] The films have an average thickness of 15 μm, as measured using a Positector electronic micrometer.

[0109] The films are clear and free of roughness and penetration defects. The bubbles were stable in all blown extrusions. Perforation of the films after blown extrusion is described as normal and without difficulty.

[0110] IV.Analysis method Tensile and tear mechanical properties may be measured using Zwick or Llyod type equipment equipped with a 50N or 5kN sensor. Properties are measured in two different directions: longitudinal and transverse. Tensile and tear mechanical properties are measured according to standards EN ISO 527-3 and ISO 6383-1, respectively.

[0111] As regards the resistance to puncture, this is measured using the Dart-Test in accordance with the standard NF EN ISO 7765-1.

[0112] The biodegradability of the films was evaluated using a depolymerization test carried out according to the following protocol: 100 mg of each sample was introduced into a plastic vial containing 50 mL of buffer solution at pH 8. Depolymerization is initiated by incubation of each sample at 45°C in an incubator with stirring at 150 RPM. Aliquots of 1 mL of buffer solution are periodically sampled, filtered using a 0.2 μm filter syringe and analyzed by high performance liquid chromatography (HPLC) using an Aminex HPX-87H column to measure the release of lactic acid (LA) and its dimers. The chromatography system used is a HPLC Nexan Series, SHIMADZU instrument equipped with a pump, an autosampler, a column thermostated at 50°C and a 220 nm UV detector. The eluent is a 5 mM H2SO4 solution. The injection volume is 20 μL of sample. Lactic acid is measured based on a standard curve made from commercially available lactic acid.

[0113] The hydrolysis of the plastic films is calculated based on the released lactic acid and lactic acid dimer. The depolymerization percentage is calculated relative to the percentage of PLA in the sample.

[0114] V.Analysis results Granule density by pycnometer The masterbatch A1 obtained by the prior art preparation method described in paragraph I.1 has a density equivalent to that of the masterbatch B1 obtained by the preparation method according to the invention described in paragraph I.2, i.e. on average 1.03 g / cm3 , has.

[0115] The masterbatch A2 obtained by the prior art preparation method described in paragraph I.1 has an equivalent density to the masterbatch B2 obtained by the inventive preparation method described in paragraph I.2, i.e. on average 1.05 g / cm 3 , has.

[0116] Masterbatch A3 obtained by the prior art preparation method described in paragraph I.1 has a density equivalent to that of masterbatch B3 obtained by the inventive preparation method described in paragraph I.2, i.e. on average 1.1 g / cm 3 , has.

[0117] The method of preparation of the support polymer and enzyme masterbatch does not affect the density of the final composite.

[0118] Melt Flow Index (MFI) Measurement Masterbatch A1 has an equivalent melt flow index to Masterbatch B1, ie 10-10.5, for an analysis carried out at 160° C. and 2.16 kg.

[0119] Masterbatch A3 has an equivalent melt flow index to Masterbatch B3, ie 10-10.5, for an analysis carried out at 160° C. and 2.16 kg.

[0120] The method of preparation of the support polymer and enzyme masterbatch does not affect the flowability of the final composite.

[0121] thermogravimetric analysis Thermogravimetric analysis performed on the two mixtures prepared in paragraph I indicates that all components in the blend have equivalent decomposition temperatures. [Table 4]

[0122] The masterbatch formulations described in paragraphs I.1 (prior art) and I.2 (present invention) are characterized by compositional differences between compounds A1 and B1; A2 and B2; and A3 and B3. These differences are observed in terms of mass loss during thermogravimetric analysis.

[0123] Only masterbatches A3 and B3 have the same composition and the mass loss does not feature significant differences due to the method used.

[0124] Film Composition Films have been prepared using the support polymer and enzyme mixtures A1-A2-A3-B1-B2-B3 prepared in I.1 and I.2, as well as a PLA and PBAT base grade sold under the reference ECOVIO F2223 by BASF and referred to as "Composite 1" in the following examples of this specification. The compositions of these different films are reported in Table 3. [Table 5] Film 1 serves as a prior art reference for Film 4 of the present invention. Film 2 serves as a prior art reference for Film 5 of the present invention. Film 3 serves as a prior art reference for Film 6 of the present invention.

[0125] The method of making the masterbatch does not affect the blown film extrusion process. The blown film extrusion parameters remain the same between the prior art and the inventive films. The appearance of the film is the same regardless of the manufacturing process used.

[0126] Mechanical properties of films 3 (prior art) and 6 (invention) The mechanical properties of films 3 and 6 obtained with masterbatches having the same composition were measured and the results are shown in Table 4. The values ​​shown are the average values ​​of all the measurements. [Table 6]

[0127] The mechanical properties thus measured show that the film 6 according to the invention has mechanical properties equal to or greater than those of the film 3 according to the prior art.

[0128] Depolymerization of PLA in films Films 1 and 2, comprising support polymer and enzyme mixture, produced under conventional conditions and with the same enzyme content, have depolymerization results comprised between 34% and 38% after 20 days at 28° C. Films 4 and 5, comprising support polymer and enzyme mixture, produced by the method described in the present invention and with the same enzyme content but less than films 1 and 2, have depolymerization results comprised between 28% and 31%.

[0129] Films 3 and 6 with identical enzyme content and MBs produced by the two steps have depolymerization rates ranging between 65 and 77% after 5 days at 45 °C.

[0130] The addition of calcium carbonate to the composition of the support polymer and enzyme mixture accelerates the depolymerization of PLA. Furthermore, the preparation method of the masterbatch does not adversely affect the performance of the enzyme in the masterbatch. The preparation method of the mixture described in the present invention makes it possible to reach a depolymerization rate close to that of the conventional method with less enzyme.

[0131] Example 2: Use of the masterbatch in flexible articles I. Preparation of the Support Polymer and Enzyme Mixture 1. Preparation of the masterbatch under conditions of the prior art (with blended enzyme solution) Support polymer and enzyme mixture A4 is prepared from granules of enzyme in solution compounded with polycaprolactone (PCL) and polysaccharide (gum arabic). Support polymer and enzyme mixture A5 is prepared from granules of enzyme in solution compounded with polycaprolactone (PCL), mineral filler (calcium carbonate, CaCO3) and polysaccharide (gum arabic). Masterbatches A4 and A5 are prepared by the procedure of Example 1.I.1 including an increasing temperature profile from 30 to 65°C.

[0132] For mixture A4, PCL is introduced into the head of the twin screw at 17 kg / h and the enzyme in solution compounded with gum arabic at 3 kg / h, using a peristaltic pump.

[0133] For mixture A5, PCL is introduced into the head of the twin screw at 17 kg / h, the enzyme in solution compounded with gum arabic at 3 kg / h using a peristaltic pump, calcium carbonate is introduced at 2 kg / h using a powder-specific metering device.

[0134] 2. Preparation of Masterbatches by the Method of the Invention (with Unformulated Enzyme Solution) The support polymer and enzyme mixture B4 is prepared from granules of polycaprolactone (PCL) and a polysaccharide (gum arabic) and enzyme in solution.

[0135] The support polymer and enzyme mixture B5 is prepared from polycaprolactone (PCL), a polysaccharide (gum arabic), a mineral filler (calcium carbonate, CaCO3) and granules of enzyme in solution.

[0136] Masterbatches B4 and B5 are prepared according to the procedure of Example 1.I.2 including an incremental temperature profile from 30 to 65°C.

[0137] For mixture B4, the enzyme in solution is introduced using a peristaltic pump at 2.2 kg / h, gum arabic is introduced using a powder-specific metering device at 0.8 kg / h, and PCL is introduced at the head of the twin screw at 17 kg / h.

[0138] For mixture B5, the enzyme in solution is introduced using a peristaltic pump at 2.2 kg / h, gum arabic is introduced using a powder-specific metering machine at 0.8 kg / h, calcium carbonate is introduced at 2 kg / h and PCL is introduced at the head of the twin screw at 15 kg / h.

[0139] Granulation of each mixture is carried out by underwater chopping. The granules are dried at 45° C. to a moisture content of 0.3%.

[0140] II. Commercially available products The commercial products used to prepare the masterbatches and films were those used for Example 1.

[0141] III. Film Manufacturing Films 7 and 8, respectively prepared with masterbatches A4 (prior art) and B4 (obtained according to the invention), are prepared according to the method described for the film of Example 1.III.

[0142] IV.Analysis method The analytical method was that described in Example 1.IV.

[0143] V.Analysis results Granule density by pycnometer Masterbatch A4 has a density equivalent to that of masterbatch B4 obtained according to the invention, i.e., an average of 1.06 g / cm 3 , has. Masterbatch A5 has a density equivalent to that of masterbatch B5 obtained according to the invention, i.e., an average of 1.4 g / cm 3 , has. The method of preparation of the support polymer and enzyme masterbatch does not affect the density of the final composite.

[0144] Melt Flow Index (MFI) Measurement Masterbatch A4 has melt flow indexes equivalent to those of masterbatch B4 obtained by the process according to the invention, namely 15.6 and 14.1 g / 10 min, respectively, for analyses carried out at 160° C. and 2.16 kg.

[0145] Masterbatch A5 has melt flow indexes equivalent to those of masterbatch B5 obtained with the preparation method of the invention, namely 18.3 and 18.9 g / 10 min, respectively, for analyses carried out at 160° C. and 2.16 kg.

[0146] The method of preparation of the support polymer and enzyme masterbatch does not affect the flowability of the final composite.

[0147] thermogravimetric analysis Thermogravimetric analysis performed on the masterbatches prepared in paragraph 2.I indicates that all components in the formulation have equivalent decomposition temperatures. [Table 7]

[0148] Masterbatches A4 and A5 (prior art) have equivalent mass losses at similar temperatures as masterbatches B4 and B5 obtained according to the invention.

[0149] The use of enzyme solutions formulated according to the prior art or unformulated enzymes according to the invention during the preparation of the masterbatches has no effect on the mass loss during thermogravimetric analysis.

[0150] Film Composition The films were prepared using the polymeric support and enzyme masterbatches A4 and B4 and a PLA and PBAT base grade sold by BASF under the reference ECOVIO F2223 and referred to in the following examples as "Composite 1". The compositions of these different films are reported in Table 9. [Table 8]

[0151] Film 7 serves as a prior art reference for Film 8 of the present invention.

[0152] The manufacturing method of the mixture has no effect on the blown film extrusion process. The parameters of the blown film extrusion process remain the same between the prior art and the inventive films. The appearance of the film is the same regardless of the manufacturing process used.

[0153] Mechanical properties of films 7 and 8 The measured mechanical properties are shown in Table 7. The values ​​shown are the average of all measurements. [Table 9]

[0154] The measured mechanical properties show that the film 8 obtained with the masterbatch B4 according to the invention has better mechanical properties than the film 7 obtained with the masterbatch A4 according to the prior art.

Claims

1. A method for preparing a masterbatch containing a polysaccharide, an enzyme capable of decomposing a polyester, and a support polymer as a mixture using a mixer, comprising: A method characterized by including the following steps: a) A step of separately and simultaneously introducing a liquid enzyme formulation, a polysaccharide, and a support polymer; b) A step of mixing them at a temperature at which the support polymer partially or completely melts; and c) A step of recovering the masterbatch after mixing.

2. The method according to claim 1, wherein the polysaccharide is selected from starch derivatives, natural rubbers, soluble soybean polysaccharides, marine extracts, and microbial and animal polysaccharides, or a mixture thereof in any ratio.

3. The method according to claim 1, wherein the polysaccharide consists of gum arabic.

4. The method according to claim 1, wherein the enzyme is added in the form of an aqueous solution.

5. The method according to claim 1, wherein the enzyme formulation contains 0.01 to 70% by weight of the enzyme.

6. The method according to claim 1, wherein the enzyme is selected from depolymerases, esterases, lipases, cutinases, carboxylesterases, proteases, and enzymes capable of decomposing the polyester selected from polyesterases.

7. The method according to claim 1, wherein the support polymer is selected from polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polydioxanone (PDS), polyhydroxyalkanoate (PHA), polylactic acid (PLA), and copolymers thereof, preferably polycaprolactone (PCL).

8. The method according to claim 1, wherein the mixing in step b) is continued for 10 to 35 seconds, preferably 15 to 35 seconds, particularly about 20 seconds, about 25 seconds, or about 30 seconds.

9. The method according to claim 1, characterized by including simultaneously adding a mineral filler, particularly calcium carbonate, in step a).

10. The method according to claim 1, wherein the mixer is an extruder.

11. 11. The method of claim 10, wherein the extruder comprises at least three zones: a head zone where the first component is inserted, a mixing zone, and an exit zone through which the masterbatch is withdrawn, according to the following steps a) to c): a) separately and simultaneously introducing an enzyme blend, a polysaccharide and, optionally, a mineral filler into the head region and mixing them at a temperature below the melting point of the support polymer; b) mixing the components in the mixing zone at a temperature at which the support polymer is partially or completely melted; c) recovering said masterbatch at the outlet of said extruder.

12. 2. The method according to claim 1, characterized in that the masterbatch is obtained in step c) in the form of granules.

13. 13. The method of claim 12, wherein the masterbatch mixture is dried.

14. 10. The method of claim 1, wherein the masterbatch formulation comprises: - 60 to 90% of the support polymer, - 10 to 20% enzyme solution, - 2 to 15% polysaccharides, - 0 to 20% mineral fillers.

15. 10. A method for preparing a plastic article or premix containing an enzymatically degradable polymer and an enzyme capable of degrading said polymer, comprising the steps of preparing a masterbatch according to claim 1 and mixing said previously prepared masterbatch with said polymer, wherein the enzyme of said masterbatch is capable of degrading the polymer of said plastic article or said premix.

16. 16. The method of claim 15, wherein the enzymatically degradable polymer of the plastic article or premix is polylactic acid (PLA).