Optically recognizable biodegradable and compostable compositions

Abstract

The present invention relates to a biodegradable and compostable polymer composition and a method for tracking the biodegradable and compostable polymer composition, comprising at least one diacid diol polyester and at least one marker, the marker comprising one or more photoactive components incorporated into a microporous inorganic material by an ion exchange reaction.

Description

[Technical Field]

[0001] The present invention relates to biodegradable compositions comprising biopolymers and photoactive markers capable of tracing them, to molded articles comprising them, and to processes for their preparation and conversion. [Background technology]

[0002] The term biopolymer generally refers to biodegradable and / or bio-based polymers. Biodegradable polymers are understood to be polymers that can be broken down and organically recycled after their primary use by serving as food for microorganisms, without accumulating waste in the environment. Compostable polymers are defined as polymers that are capable of decomposition and biodegradation according to European Standards EN 14995 (plastics) and EN 13432 (packaging). Bio-based polymers are defined as those that are obtained from natural or renewable resources, i.e., those that, by their nature, can be obtained from resources that are renewable within the timescale of a human lifetime.

[0003] As biopolymer compositions (so-called bioplastics) become widely used as alternatives to conventional plastics, sustainability can be further enhanced by increasing the possibility of recovering and reusing the monomers from which bioplastics are made, which would minimize land use and renewable CO2 production and enable a truly circular economy. Therefore, in parallel with the recycling of conventional plastics, new methods for recycling and reusing bioplastics are also being developed.

[0004] However, while conventional plastics can be recycled in existing waste management and treatment plants, for biodegradable materials, alternative and specific solutions based on the chemical and physical properties of such innovative materials are needed. Therefore, while current bioplastics recycling technologies include mechanical recycling, chemical recycling, and enzymatic depolymerization, prior to these, it is essential to carry out appropriate sorting of industrial and post-consumer waste to select material streams with low variability in composition and purity that are suitable for specific recycling processes. For this purpose, it is known that plastic materials can be identified and separated by optical methods.

[0005] However, a problem often arises in that plastics contain, in addition to the polymer matrix, other contaminants that can affect the optical properties of the plastic material. These contaminants can be, for example, pigments, dyes, or other additives added during industrial processing, or they can be derived from the use of the material, such as organic or inorganic residues. In addition, materials can become discolored or opaque over time as a result of exposure to, for example, light, heat, or chemicals. As a result, plastics of the same chemical class can have different colors and can give different results in absorption or reflectance measurements at a defined wavelength or wavelength band, making it very difficult to achieve uniform optical identification of these materials, regardless of the amount of contaminants or contamination they contain, or the degree of use or aging. For this reason, selection methods based on target labels or the incorporation of materials containing luminescent substances have been developed, as described in patent application US 2019 / 329297 A1. Summary of the Invention [Problem to be solved by the invention]

[0006] However, the special conditions of preparing and processing biodegradable plastics, which involve high-temperature heat treatment, can lead to the degradation of the properties of the luminescent organic substances incorporated in them. Therefore, it is necessary to find a way to stabilize these substances without affecting the processability of biodegradable plastic materials and without impairing their biodegradability during processing into final products. [Means for solving the problem]

[0007] The applicants have now overcome this problem by incorporating an innovative marker system into biodegradable plastic materials, allowing for efficient detection using existing optical detection technologies. The use of a marker whose photoactive component is protected by being incorporated into a microporous inorganic material ensures effective detection. This marking system prevents the photoactive component from oxidizing and thermally degrading when incorporated into a polymer composition, while preserving its luminescent properties. In addition to being stable, the marker is compatible with the main processes for preparing and processing polymeric materials, and thanks to its unique luminescent properties, it is compatible with the optical properties of the polymeric material itself and is detectable even at low concentrations and in the presence of any additives. Biodegradable polymer compositions incorporating such marker systems are particularly suitable for use in tracking items containing them, for example in waste sorting or end-of-life recovery processes.

[0008] An object of the present invention is therefore a biodegradable and compostable polymer composition comprising at least one diacid diol polyester (i), optionally one or more polyhydroxyalkanoates (ii), optionally one or more fillers (iii), and at least one marker (iv) comprising one or more photoactive components incorporated into a microporous inorganic material by ion exchange reaction. [Effects of the Invention]

[0009] The biodegradable polymer composition can be easily prepared by a simple and inexpensive procedure in which the biodegradable plastic material can be processed in subsequent processing steps to ensure the final product. The present invention will be described in more detail below. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 shows the spectrum of the biodegradable and compostable polymer composition prepared in Comparative Example 1 and the spectrum of the biodegradable and compostable polymer composition according to the invention prepared in Example 2, further including the marker 0.085% w. [Figure 2] FIG. 2 shows the spectrum of the biodegradable and compostable polymer composition prepared in Comparative Example 3 and the spectrum of the biodegradable and compostable polymer composition according to the invention prepared in Example 4, further including the marker 0.085% w. [Figure 3] FIG. 3 shows the spectrum of the biodegradable and compostable polymer composition containing filler prepared in Comparative Example 5 and the spectrum of the biodegradable and compostable polymer composition according to the invention prepared in Example 6, further including the marker 0.051% w. DETAILED DESCRIPTION OF THE INVENTION

[0011] The biodegradable polymer composition according to the invention comprises at least one diacid-diol polyester (i), said polyester being biodegradable according to EN 13432 and may be of either aliphatic or aliphatic-aromatic type. With regard to aliphatic-aromatic polyesters, they have an aromatic portion consisting primarily of polyfunctional aromatic acids and an aliphatic portion consisting primarily of aliphatic diacids, aliphatic diols, and mixtures thereof. Aliphatic polyesters are derived from aliphatic diacids, aliphatic diols and mixtures thereof. Polyfunctional aromatic acids are understood to mean dicarboxylic aromatic compounds of the phthalic acid type, preferably terephthalic acid or isophthalic acid, more preferably terephthalic acid, and heterocyclic dicarboxylic aromatic compounds, preferably 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, esters, salts and mixtures thereof.

[0012] In a preferred embodiment, the aromatic dicarboxylic acid comprises: 1 to 99 mol %, preferably 5 to 95 mol %, more preferably 10 to 80 mol % of terephthalic acid, its esters or salts; 99 to 1 mol %, preferably 95 to 5 mol %, more preferably 90 to 20 mol % of 2,5-furandicarboxylic acid, an ester or a salt thereof.

[0013] The aliphatic diacid is a C2 to C24, preferably C4 to C13, more preferably C4 to C11 aliphatic dicarboxylic acid, their C1 to C24, more preferably C1 to C4 alkyl esters, their salts, and mixtures thereof. Preferably, the aliphatic dicarboxylic acid is selected from succinic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, and their C1 to C24 alkyl esters. Preferably, the aliphatic dicarboxylic acid is selected from the group consisting of succinic acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, and mixtures thereof.

[0014] The dicarboxylic acid component of the aliphatic or aliphatic-aromatic polyester according to the present invention may comprise up to 5% of an unsaturated aliphatic dicarboxylic acid, preferably selected from itaconic acid, fumaric acid, 4-methylene-pimelic acid, 3,4-bis(methylene)nonanedioic acid, 5-methylene-nonanedioic acid, their C1-C24, preferably C1-C4 alkyl esters, their salts, and mixtures thereof. In a preferred embodiment of the present invention, the unsaturated aliphatic dicarboxylic acid comprises a mixture comprising at least 50 mol%, preferably more than 60 mol%, and more preferably more than 65 mol% of itaconic acid and / or its C1-C24, preferably C1-C4 esters. More preferably, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid.

[0015] In the aliphatic or aliphatic-aromatic polyesters according to the invention, the diol is preferably 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,4-cyclohexanone ... The diol component is understood to be a compound having two hydroxy groups selected from dimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitol, dianhydromannitol, dianhydroiditol, cyclohexanediol, 1,4-bis(hydroxymethyl)cyclohexane, dialkylene glycols, and polyalkylene glycols having a molecular weight of 100 to 4,000, such as polyethylene glycol, polypropylene glycol, and mixtures thereof. Preferably, the diol component comprises at least 50 mol% of one or more diols selected from 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol. In a preferred embodiment of the present invention, the saturated aliphatic diol is 1,4-butanediol. Advantageously, the diols are obtained from renewable resources, from first or second generation sugars.

[0016] The diol component of the aliphatic or aliphatic-aromatic polyester according to the present invention may contain up to 5% of an unsaturated aliphatic diol, preferably selected from cis 2-butene-1,4-diol, trans 2-butene-1,4-diol, 2-butyne-1,4-diol, cis 2-pentene-1,5-diol, trans 2-pentene-1,5-diol, 2-pentyne-1,5-diol, cis 2-hexene-1,6-diol, trans 2-hexene-1,6-diol, 2-hexene-1,6-diol, cis 3-hexene-1,6-diol, trans 3-hexene-1,6-diol, and 3-hexene-1,6-diol.

[0017] The polyester according to the invention may advantageously comprise repeat units derived from at least one hydroxy acid in an amount of 0 to 49 mol %, preferably 0 to 30 mol %, relative to the total moles of the dicarboxylic acid component. Examples of useful hydroxy acids are glycolic acid, glycolide, hydroxybutyric acid, hydroxycaproic acid, hydroxyvaleric acid, 7-hydroxyheptanoic acid, 8-hydroxycaproic acid, 9-hydroxynonanoic acid, lactic acid or lactide. The hydroxy acids may be inserted into the chain as such, as prepolymers / oligomers, or may be previously reacted with diacids and / or diols.

[0018] According to a preferred embodiment of the present invention, the diacid diol polyester (i) is an aliphatic-aromatic polyester. The aliphatic-aromatic polyester (i) is preferably present in an amount of 5 to 99.9% by weight of the total composition. According to one embodiment of the invention, it is present in an amount of 5 to 50% by weight, preferably 10 to 40% by weight, of the total composition. According to another embodiment of the invention, it is present in an amount of 90 to 99.9% by weight, based on the total weight of the composition, and preferably represents the only polymeric component therein. The aliphatic-aromatic polyester according to the present invention is characterized in that the aromatic acid content relative to the total dicarboxylic acid components is 30 to 70 mol %, preferably 40 to 60 mol %.

[0019] In a preferred embodiment, the aliphatic-aromatic polyester is preferably poly(1,4-butylene adipate-co-1,4-butylene terephthalate), poly(1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene azelate-co-1,4-butylene terephthalate), poly(1,4-butylene brassylate-co-1,4-butylene terephthalate), poly(1,4-butylene succinate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4 poly(1,4-butyleneazelate-co-1,4-butylenesebacate-co-1,4-butyleneterephthalate), poly(1,4-butyleneadipate-co-1,4-butyleneazelate-co-1,4-butyleneterephthalate), poly(1,4-butylenesuccinate-co-1,4-butylenesebacate-co-1,4-butyleneterephthalate), poly(1,4-butyleneadipate-co-1,4-butylenesuccinate-co-1,4-butyleneterephthalate), poly(1,4-butyleneazelate-co-1,4-butylenesuccinate-co-1,4-butyleneterephthalate), and mixtures thereof. In a particularly preferred embodiment, the aliphatic-aromatic polyester is poly(1,4-butylene adipate-co-1,4-butylene terephthalate).

[0020] According to another preferred embodiment of the present invention, the diacid diol polyester (i) is an aliphatic polyester. The aliphatic polyester preferably contains a dicarboxylic acid component containing 95 to 100 mol % of units derived from at least one saturated aliphatic dicarboxylic acid II and 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid, based on the total dicarboxylic acid components, and further contains a diol component containing 95 to 100 mol % of units derived from at least one saturated aliphatic diol and 0 to 5 mol % of units derived from at least one unsaturated aliphatic diol, based on the total diol components.

[0021] In a particularly preferred embodiment, the aliphatic polyester (i) according to the present invention is selected from the group consisting of poly(1,4-butylene succinate), poly(1,4-butylene succinate-co-adipate), poly(1,4-butylene succinate-co-1,4-butylene azelate), and mixtures thereof. The aliphatic polyester (i) is present in an amount of up to 80% by weight of the total composition, preferably from 20 to 60% by weight.

[0022] The aliphatic and / or aliphatic / aromatic polyester layer (i) according to the present invention may further advantageously comprise repeating units derived from at least one hydroxy acid in an amount of 0 to 49 mol %, preferably 0 to 30 mol %, based on the total moles of the dicarboxylic acid component. Examples of convenient hydroxy acids are glycolic acid, hydroxybutyric acid, hydroxycaproic acid, hydroxyvaleric acid, 7-hydroxyheptanoic acid, 8-hydroxycaproic acid, 9-hydroxynonanoic acid, lactic acid, or lactide. The hydroxy acids may be incorporated into the chain as such or as prepolymers / oligomers, or they may also be reacted beforehand with diacids or diols.

[0023] Alternatively, dicarboxylic acid components containing long molecules with two functional groups, including a non-terminal functional group, may be added in an amount of 10 mol % or less based on the total number of moles, such as dimer acid, ricinoleic acid, and acid having an epoxy group, as well as polyoxyethylene having a molecular weight of 200 to 10,000. The diamine, amino acid, and amino alcohol may be present in an amount of up to 30 mol % based on the total number of moles of the dicarboxylic acid component.

[0024] In the process for preparing the aliphatic and / or aliphatic / aromatic polyesters (i) according to the invention, one or more polyfunctional molecules may be advantageously added in an amount of 0.1 to 3 mol % relative to the total number of moles of dicarboxylic acid components in order to obtain branched products. Examples of such molecules are glycerol, pentaerythritol, trimethylolpropane, citric acid, dipentaerythritol, monoanhydrosorbitol, monoanhydromannitol, acid triglycerides, polyglycerols, etc.

[0025] The molecular weight Mn of the aliphatic and / or aliphatic-aromatic polyester (i) is preferably ≧20000, more preferably ≧40000. The molecular weight polydispersity index Mw / Mn is preferably 1.5 to 10, more preferably 1.6 to 5, and even more preferably 1.8 to 2.7. The molecular weights Mn and Mw may be measured by gel permeation chromatography (GPC) using a chromatographic system maintained at 40°C, two columns in series (particle sizes 5 μm and 3 μm, mixed porosity), a refractive index detector, chloroform as eluent (flow rate 0.5 ml / min), and polystyrene as standards.

[0026] The melt flow rate (MFR) of the aliphatic and / or aliphatic-aromatic polyester (i) is preferably 500 to 1 g / 10 min, more preferably 100 to 3 g / 10 min, and even more preferably 20 to 3 g / 10 min (measurement carried out at 190°C / 2.16 kg according to ISO 1133-1 "Plastics - Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics - Part 1: Standard method"). The terminal acid group content of said aliphatic and / or aliphatic-aromatic polyesters (i) is preferably less than 100 meq / kg, preferably less than 60 meq / kg, even more preferably less than 40 meq / kg.

[0027] The acid end group content can be determined as follows: 1.5-3 g of polyester is placed in a 100 ml conical flask with 60 ml of chloroform. After the polyester is completely dissolved, 25 ml of 2-propanol is added, followed by 1 ml of deionized water immediately before analysis. The resulting solution is titrated with a pre-standardized NaOH solution in ethanol. The equivalence point of the titration is determined using an appropriate indicator, such as a glass electrode for acid-base titrations in non-aqueous solvents. The acid end group content is calculated based on the amount of NaOH solution in ethanol consumed according to the following formula:

[0028]

number

[0029] where Veq = ml of NaOH solution in ethanol at the equivalence point of the sample titration; Vb = ml of NaOH solution in ethanol required to achieve pH = 9.5 in the blank titration; T = concentration of NaOH solution in ethanol (mol / liter); P = sample weight (grams).

[0030] Preferably, the aliphatic and / or aliphatic / aromatic diacid diol polyester (i) has an intrinsic viscosity (measured with an Ubbelohde viscometer on a solution in CHCl3 at a concentration of 0.2 g / dl at 25°C) of more than 0.3 dl / g, preferably between 0.3 and 2 dl / g, more preferably between 0.4 and 1.4 dl / g. Said polyester (i) may be synthesized according to any of the processes known in the art, and in particular may be advantageously obtained by polycondensation reactions.

[0031] Advantageously, the synthesis step may be carried out in the presence of a suitable catalyst, examples of which include organometallic tin compounds such as stannic acid derivatives, titanium compounds such as orthobutyl titanate, aluminum compounds such as Al-triisopropyl, antimony, and zinc and zirconium compounds, and mixtures thereof.

[0032] Examples of synthetic processes that can be advantageously used to prepare polyesters are described in International Patent Application WO 2016 / 050963.

[0033] The biodegradable and compostable polymer composition according to the present invention may further optionally comprise at least one crosslinker and / or chain extender in an amount of 0-5% by weight of the total mixture, more preferably 0.05-4% by weight, even more preferably 0.05-3% by weight.

[0034] The crosslinking agent and / or chain extender improves the hydrolytic stability and is selected from di- and / or polyfunctional compounds having isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxy, anhydride, divinyl ether groups and mixtures thereof. Preferably, the crosslinking agent and / or chain extender comprises at least one di- and / or polyfunctional compound having an epoxide or carbodiimide group.

[0035] Preferably, the crosslinking agent and / or chain extender comprises at least one di- and / or polyfunctional compound having an isocyanate group. More preferably, the crosslinking agent and / or chain extender comprises at least 25% by weight of one or more di- and / or polyfunctional compounds having an isocyanate group. Particularly preferred is a mixture of a di- and / or polyfunctional compound having an isocyanate group and a di- and / or polyfunctional compound having an epoxide group, and even more preferably comprises at least 75% by weight of a di- and / or polyfunctional compound having an isocyanate group. Preferably, the difunctional and polyfunctional compounds having an isocyanate group are p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene-4-chlorodiisocyanate, 1,5-naphthalene diisocyanate, 4,4-diphenylene diisocyanate, 3,3'-dimethyl-4,4-diphenylmethane diisocyanate, 3-methyl-4,4'-diphenylmethane diisocyanate, diphenyl ether diisocyanate, 2,4-cyclohexane diisocyanate, 2,3-cyclohexane diisocyanate, 1-methyl-2,4-cyclo The isocyanate group-containing compound is selected from the group consisting of hexyl diisocyanate, 1-methyl-2,6-cyclohexyl diisocyanate, bis(isocyanatocyclohexyl)methane, 2,4,6-toluene triisocyanate, 2,4,4-diphenyl ether triisocyanate, polymethylene-polyphenyl-polyisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, 3,3'-ditolylene-4,4-diisocyanate, 4,4'-methylenebis(2-methyl-phenylisocyanate), hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,2-cyclohexylene diisocyanate, and mixtures thereof. In a preferred embodiment, the compound having an isocyanate group is 4,4-diphenylmethane diisocyanate.

[0036] As regards the difunctional and polyfunctional compounds having peroxide groups, they are preferably selected from benzoyl peroxide, lauroyl peroxide, isononanoyl peroxide, di-(t-butylperoxyisopropyl)benzene, t-butyl peroxide, dicumyl peroxide, α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hex-3-yne, di(4-t-butylcyclohexyl)peroxydicarbonate, dicetyl peroxycarbonate, dimyristyl peroxycarbonate, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxinane, di(2-ethylhexyl)peroxycarbonate and mixtures thereof.Di- and polyfunctional compounds containing carbodiimide groups which are preferably used in the mixtures according to the invention are poly(cyclooctylenecarbodiimide), poly(1,4-dimethylcyclohexylenecarbodiimide), poly(cyclohexylenecarbodiimide), poly(ethylenecarbodiimide), poly(butylenecarbodiimide), poly(isobutylenecarbodiimide), poly(nonylenecarbodiimide), poly(dodecylenecarbodiimide), poly(neopentylenecarbodiimide), poly(1,4-dimethylenephenylenecarbodiimide), poly(2,2',6,6'-tetraisopropyldiphenylenecarbodiimide) (Stabaxol® D), poly(2,4,6-triisopropyl-1,3-phenylenecarbodiimide) (Stabaxol® P-100), poly(2,6-diisopropyl-1,3-phenylenecarbodiimide) (Stabaxol® P), poly(tolylcarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-biphenylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(isophoronecarbodiimide), poly(cumenecarbodiimide), p-phenylenebis(ethylcarbodiimide), 1,6-hexamethylenebis(ethylcarbodiimide), 1,8-octamethylenebis(ethylcarbodiimide), 1,10-decamethylenebis(ethylcarbodiimide), 1,12-dodecamethylenebis(ethylcarbodiimide), and mixtures thereof.

[0037] Examples of di- and polyfunctional compounds containing epoxy groups that can be advantageously used in the mixtures according to the invention are epoxidized oils and / or styrene-glycidyl ether-methyl methacrylate, all polyepoxides from glycidyl ether-methyl methacrylate, with a molecular weight in the range of 1000 to 10000 and with an epoxide number per molecule in the range of 1 to 30, preferably 5 to 25, as well as diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, 1,2- The epoxide is selected from the group consisting of epoxybutane, polyglycerol polyglycidyl ether, isoprene diepoxide, and cycloaliphatic diepoxide, 1,4-cyclohexanedimethanol diglycidyl ether, glycidyl 2-methylphenyl ether, glycerol propoxylate triglycidyl ether, 1,4-butanediol diglycidyl ether, sorbitol polyglycidyl ether, glycerol diglycidyl ether, tetraglycidyl ether of metaxylenediamine, and diglycidyl ether of bisphenol A, and mixtures thereof.

[0038] In a particularly preferred embodiment of the present invention, the crosslinking agent and / or chain extender comprises a compound having an isocyanate group, preferably 4,4-diphenylmethane diisocyanate, and / or a compound having a carbodiimide group, and / or a compound having an epoxide group, preferably an epoxide group of the styrene-glycidyl ether-methyl methacrylate type. In a particularly preferred embodiment of the present invention, the crosslinking agent and / or chain extender comprises a compound having an epoxy group of the styrene-glycidyl ether-methyl methacrylate type. In addition to difunctional and polyfunctional compounds having isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxy, anhydride, or divinyl ether groups, catalysts may also be used to increase the reactivity of the reactive groups. In the case of polyepoxides, fatty acid salts are preferably used, and even more preferably calcium stearate and zinc stearate are used.

[0039] The composition according to the present invention optionally contains a polyhydroxyalkanoate (ii), preferably in an amount of at least 1% by weight, more preferably at least 5% by weight, based on the total composition. Advantageously, it is present in an amount of 20 to 80% by weight, more preferably 40 to 75% by weight, and even more preferably 55 to 70% by weight, based on the total composition. The polyhydroxyalkanoate (ii) is preferably selected from the group consisting of lactic acid polyesters, poly-ε-caprolactone, polyhydroxybutyric acid, polyhydroxybutyric acid-valeric acid, polyhydroxybutyric acid-propanoic acid, polyhydroxybutyric acid-hexanoic acid, polyhydroxybutyric acid-decanoic acid, polyhydroxybutyric acid-dodecanoic acid, polyhydroxybutyric acid-hexadecanoic acid, polyhydroxybutyric acid-octadecanoic acid, poly-3-hydroxybutyric acid-4-hydroxybutyric acid, and mixtures thereof. Preferably, the polyhydroxyalkanoate (ii) of the composition comprises at least 70% by weight, more preferably at least 80% by weight, of one or more lactic acid polyesters. In a preferred embodiment, the lactic acid polyester is selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, poly-DL-lactic acid stereocomplex, copolymers containing more than 50% by weight of the lactic acid polyester, or mixtures thereof. Particularly preferred are those containing at least 95% by weight of repeating units derived from L-lactic acid or D-lactic acid or mixtures thereof, having a molecular weight Mw of more than 50,000, and a shear viscosity of 50 to 700 Pa.s, preferably 80 to 500 Pa.s (according to ASTM D3835 standard, T=190°C, shear rate=1000 s). -1 , D=1 mm, L / D=10).

[0040] In a particularly preferred embodiment of the present invention, the lactic acid polyester comprises at least 95% by weight of repeating units derived from L-lactic acid and 5% by weight or less of repeating units derived from D-lactic acid, and has a melting temperature in the range of 135-175°C, a glass transition temperature (Tg) in the range of 55-65°C, and a MFR in the range of 1-50 g / 10 min (measured at 190°C and 2.16 kg according to ASTM-D1238 standard). Commercially available examples of lactic acid polyesters having these properties include Ingeo™ Biopolymer brand products 4043D, 3251D, and 6202D, and Luminy® brand product L105.

[0041] In a preferred embodiment of the present invention, the composition comprises 5 to 50% by weight, preferably 10 to 45% by weight, and even more preferably 15 to 40% by weight, of at least one diacid diol polyester (i) of the aliphatic-aromatic type, relative to the sum of components (i) and (ii), and 50 to 95% by weight, preferably 55 to 80% by weight, and even more preferably 58 to 75% by weight, of lactic acid polyester (ii), relative to the sum of components (i) and (ii).

[0042] In the compositions according to the invention, the diacid diol polyesters (i) may be mixed with other polymers of synthetic or natural origin, whether biodegradable or not. As regards the biodegradable and non-biodegradable polymers of synthetic or natural origin, they are advantageously selected from the group consisting of vinyl polymers, diacid-diol polyesters other than or identical to the abovementioned aliphatic and / or aliphatic-aromatic polyesters, polyamides, polyurethanes, polyureas, polycarbonates and mixtures thereof. In a particularly preferred embodiment, said polymers may be mixed with the biodegradable polyesters according to the invention in amounts of up to 80% by weight.

[0043] Preferred vinyl polymers include polyethylene, polypropylene, their copolymers, polyvinyl alcohol, polyethylene vinyl acetate and polyethylene vinyl alcohol, polystyrene, chlorinated vinyl polymers, and polyacrylates. The term "chlorinated vinyl polymers" includes polyvinyl chloride, polyvinylidene chloride, poly(vinyl chloride-vinyl acetate), poly(vinyl chloride-ethylene), poly(vinyl chloride-propylene), poly(vinyl chloride-styrene), poly(vinyl chloride-isobutylene), and copolymers containing greater than 50 mole percent polyvinyl chloride. Such copolymers may be random, block, or alternating.

[0044] The polyamides are preferably selected from the group consisting of polyamides 6 and 6.6, polyamides 9 and 9.9, polyamides 10 and 10.10, polyamides 11 and 11.11, polyamides 12 and 12.12, and combinations of these of the 6 / 9, 6 / 10, 6 / 11, 6 / 12 type, blends thereof, and both random and block copolymers.

[0045] Preferably, the polycarbonate of the composition according to the invention is selected from the group consisting of polyalkylene carbonates, more preferably polyethylene carbonate, polypropylene carbonate, polybutylene carbonate, blends thereof, and both random and block copolymers.

[0046] Among the polyethers, preferred are those selected from the group consisting of polyethylene glycol, polypropylene glycol, polybutylene glycol, copolymers thereof and blends thereof, and have a molecular weight of 70,000 to 500,000.

[0047] For diacid diol polyesters, preferred include: Compared to the total dicarboxylic acid content, (a1) 20 to 100 mol % of units derived from at least one aromatic dicarboxylic acid, (a2) 0 to 80 mol % of units derived from at least one saturated aliphatic dicarboxylic acid, (a3) a dicarboxylic acid component containing 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid; Compared to the total diol content, (b1) 95 to 100 mol % of units derived from at least one saturated aliphatic diol; (b2) A diol component containing 0 to 5 mol % of units derived from at least one unsaturated aliphatic diol.

[0048] Preferably, the aromatic aliphatic dicarboxylic acid a1, the saturated aliphatic dicarboxylic acid a2, the unsaturated aliphatic dicarboxylic acid a3, the saturated aliphatic diol b1 and the unsaturated aliphatic diol b2 of the polyester are selected from those described above for the diacid diol polyester (i) according to the invention.

[0049] As regards the polymers of natural origin, they are advantageously chosen from starch, chitin, chitosan, alginates, proteins such as gluten, zein, casein, collagen, gelatin, natural gums, cellulose (also in nanofibrils) and pectin, each of which is preferably present in an amount of up to 40% by weight, more preferably up to 30% by weight, relative to the total weight of the composition.

[0050] A preferred example is cellulose fiber, present in an amount of 1-25 wt.%, more preferably 4-15 wt.%, preferably having a length to diameter (L / D) ratio <40, more preferably L / D <30, even more preferably L / D <20, and not causing an excessive increase in the modulus or a significant decrease in the tensile stress at break of the polymer composition, or a significant decrease in the flowability in the molten state.

[0051] Another preferred example of a naturally occurring polymer that may be present in the compositions of the present invention is starch. The term "starch" is understood here to mean all types of starch, i.e., wheat flour, native starch, hydrolyzed starch, destructured starch, gelatinized starch, plasticized starch, thermoplastic starch, biofillers including complex starches, or mixtures thereof. Particularly preferred according to the invention are starches such as potato, corn, tapioca, and pea starch. Particularly advantageous are starches that are easily degradable and have a high initial molecular weight, such as potato or corn starch. The starch can be present as is or in a chemically modified form, such as starch esters with a degree of substitution of 0.2 to 2.5, hydroxypropylated starch, or modified starches with fatty chains. For destructured starch, reference is made here to the teachings contained in patents EP-0 118240 and EP-0 327 505, where the starch is treated in such a way that it does not substantially exhibit the so-called "Maltese cross" under polarized light microscopy or the so-called "ghost" under phase-contrast light microscopy. Advantageously, the destructuring of starch is carried out by extrusion at temperatures between 110 and 250°C, preferably between 130 and 180°C, and at pressures between 0.1 and 7 MPa, preferably between 0.3 and 6 MPa, preferably with a specific energy of greater than 0.1 kWh / kg during the extrusion process. The destructuring of starch is preferably carried out in the presence of 1 to 40% by weight, relative to the weight of the starch, of one or more plasticizers selected from water and polyols having 2 to 22 carbon atoms. The moisture content may be that naturally present in the starch. Among polyols, polyols containing 2 to 6 carbon atoms and 1 to 20 hydroxy groups, their ethers, thioethers, and organic and inorganic esters are preferred. Examples of the polyols include glycerol, diglycerol, polyglycerol, pentaerythritol, ethoxylated polyglycerol, ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, sorbitol, sorbitol monoacetate, sorbitol diacetate, sorbitol monoethoxylate, sorbitol diethoxylate, and mixtures thereof.In a preferred embodiment, the starch is destructured in the presence of glycerol or a mixture of plasticizers comprising glycerol, more preferably a mixture of plasticizers comprising 2 to 90% by weight of glycerol. Preferably, the destructured and crosslinked starch according to the invention comprises 1 to 40% by weight of plasticizer, based on the weight of starch. When present, the starch in the composition according to the invention is preferably in the form of particles with a round, elliptical or other ellipsoid cross-section, with an average diameter, measured taking into account the longest axis of the particle, of less than 1 μm, more preferably less than 0.5 μm.

[0052] The compositions according to the invention comprising starch are particularly suitable for use in film formation, to obtain monolayer or multilayer films.

[0053] The composition according to the invention further optionally comprises one or more fillers or fillers (iii) in an amount of 0 to 50% by weight, or in a preferred embodiment 1 to 40% by weight, relative to the total weight of the composition. The fillers have an average particle size greater than 700 nm, preferably >800 nm, more preferably >1 μm. Advantageously, for some applications, the particle size of the fillers, as measured by dynamic light scattering, is characterized by a distribution with a D95 of 10 micrometers or less. Examples of particularly preferred fillers are talc, clay, silica, mica, kaolin, titanium dioxide, calcium carbonate, wollastonite and mixtures thereof, with talc and calcium carbonate being preferred.

[0054] Components (i) to (iii) of the polymer composition according to the present invention and / or mixtures thereof are characterized by a transmittance in the range of 900 nm to 1650 nm of more than 50%, preferably more than 60%, even more preferably more than 70%. According to a preferred embodiment, component (i) is characterized by a transmittance of more than 60%, preferably more than 70%, in the range from 600 nm to 800 nm, in which case component (i) is preferably an aliphatic-aromatic polyester.

[0055] As regards the photoactive components of the marker iv), they are characterized by being organic in nature and fluorescent. Photoactive components characterized by a luminescence emission in the range of 550-650 nm are particularly suitable for use in the marker iv) according to the invention. Advantageously, the rhodamine family and their derivatives bearing fluorophore groups are used, as such fluorescent dyes can be easily and inexpensively detected using techniques known in the art, such as spectrofluorimetry, for example using a fluorometer.

[0056] An example of a photoactive component is rhodamine B. The photoactive component is incorporated into a microporous inorganic material by ion exchange. This inorganic material has pores with a size of 4 to 12 Å and is a zeolite. This results in a dye-exchanged zeolite marker. An example of a possible preparation method for the dye-exchanged zeolite marker is described in IT Patent Application No. 102022000016188.

[0057] Said marker (iv) is preferably present in the biodegradable and compostable composition according to the invention in an amount of at least 0.01% by weight, more preferably at least 0.025% by weight, even more preferably at least 0.05% by weight, relative to the weight of the composition. For example, an amount of at least 0.1% by weight is advantageously used. Marker (iv) is advantageously present in an amount of at most 0.5% by weight, preferably at most 0.3% by weight, for example 0.1 to 0.2% by weight, relative to the total weight of the composition.

[0058] The biodegradable polymer composition according to the present invention may further comprise one or more optional additives selected from the group consisting of plasticizers, UV stabilizers, lubricants, nucleating agents, surfactants, antistatic agents, pigments, compatibilizers, lignin, organic acids, antioxidants, mildewcides, waxes and processing aids, as well as polymer components preferably selected from the group consisting of vinyl polymers and diacid-diol polyesters different from or the same as the aliphatic and / or aliphatic-aromatic polyesters mentioned above. Each additive is preferably present in an amount of less than 10% by weight, more preferably less than 5% by weight, and even more preferably less than 1% by weight of the total weight of the mixture.

[0059] As for the plasticizer, in addition to the plasticizers preferably used in the preparation of the destructured starch described above, it is preferably selected from the group consisting of trimellitates, such as trimellitic acid esters with C4 to C20 monoalcohols selected from the group consisting of n-octanol and n-decanol, and aliphatic esters having the following structure:

[0060] R1-O- C(O)-R4-C(O)-[-O-R2-OC(O)-R5-C(O)-]mO-R3

[0061] wherein R1 is selected from one or more of H, C1-C24 linear and branched saturated and unsaturated alkyl residues, and a group formed by a residue of a polyol esterified with a C1-C24 monocarboxylic acid; R2 comprises a -CH2-C(CH3)2-CH2- group and a C2-C8 alkylene group, and at least 50 mol% of said -CH2-C(CH3)2-CH2- group; R3 is selected from one or more of H, C1-C24 linear and branched saturated and unsaturated alkyl residues, and a group formed by a polyol esterified with a C1-C24 monocarboxylic acid; R4 and R5 are the same or different and comprise one or more C2-C22, preferably C2-C11, more preferably C4-C9 alkenes, and at least 50 mol% of C7 alkenes; and m is a number from 1 to 20, preferably from 2 to 10, more preferably from 3 to 7. Preferably, in the ester, at least one of the R1 and / or R3 groups comprises a polyol residue esterified with at least one C1-C24 monocarboxylic acid selected from the group consisting of stearic acid, palmitic acid, 9-ketostearic acid, 10-ketostearic acid, and mixtures thereof, preferably in an amount of at least 10 mol %, more preferably at least 20 mol %, and even more preferably at least 25 mol %, based on the total amount of R1 and / or R3 groups. Examples of such aliphatic esters are described in Italian Patent Application MI2014A000030 and International Patent Applications WO2015 / 104375 and WO2015 / 104377.

[0062] The lubricant is preferably chosen from esters and metal salts of fatty acids, such as zinc stearate, calcium stearate, aluminum stearate, and acetyl stearate. Preferably, the composition according to the invention comprises up to 1% by weight, more preferably up to 0.5% by weight, of a lubricant relative to the total weight of the composition.

[0063] Examples of nucleating agents include saccharin sodium salt, calcium silicate, sodium benzoate, calcium titanate, boron nitride, isotactic polypropylene, and low molecular weight PLA.

[0064] Pigments may be added as needed, such as clay, azo pigments (such as the red pigment "Basic Red 18" and the yellow pigment "Corimax Yellow H10G"), hydrazone pigments, polycyclic organic pigments (such as the blue pigment "Pigment Blue 62"), titanium dioxide, silicates, iron oxides and hydroxides, carbon black, and magnesium oxide. Inorganic pigments advantageously have an average particle size greater than 700 nm, preferably greater than 800 nm, and more preferably greater than 1 μm.

[0065] Processing aids such as sliding and / or mold release agents include, for example, biodegradable fatty acid amides such as oleamide, erucamide, ethylene-bis-stearylamide, fatty acid esters such as glycerol oleate or glycerol stearate, or saponified fatty acids such as stearates. The processing aid is preferably present in an amount of less than 10 wt. %, more preferably less than 5 wt. %, and even more preferably less than 1 wt. % of the total weight of the mixture.

[0066] Advantageously, the polymer composition according to the invention is produced by an extrusion process in which the components are mixed in the molten state. When extruding the composition, the components can be fed together or one or more components can be fed separately along the extruder.

[0067] Since microporous inorganic marker materials (iv) usually have a high tendency to adsorb water, they are advantageously dehydrated or dried prior to incorporation into the composition of the present invention. For example, the marker is dried (e.g., in a vacuum oven at 90°C for at least one hour) to a moisture content of less than 1000 ppm, preferably quickly or under a nitrogen stream to avoid absorption of atmospheric moisture. This avoids introducing excessive amounts of water into the extrusion process, which can lead to instability and non-uniformity during the extrusion process. Dispersing the marker (iv) in a masterbatch also improves processability and uniform distribution of small amounts of the marker in the final product. For example, the marker, preferably dried, can be physically mixed with additional components of the biodegradable polymer composition to obtain a physical mixture (dry blend) that can be further dried to remove residual moisture. The physical blend of the dried marker and components of the biodegradable and compostable polymer composition can then be fed into an extruder.

[0068] The marking system according to the present invention has the added benefit of limiting migration of photoactive components into the final product, which is advantageous in applications where this is a problem (eg food contact). Therefore, a further aspect of the present invention relates to a process for the preparation of a biodegradable polymer composition comprising the steps of: a) drying a marker comprising a photoactive component supported on a microporous inorganic material until a moisture content of less than 2000 ppm is obtained, preferably a moisture content of <1500 ppm, more preferably a moisture content of <1000 ppm; b) incorporating said marker (dispersed phase) into one or more of components (i) to (iii) of a biodegradable polymer composition (dispersant phase) by extrusion, preferably at a peak temperature of 120°C to 220°C, preferably 130°C to 180°C.

[0069] According to a preferred embodiment of the present invention, the marker is preferably mixed with the polymer dispersant phase in an amount of 10 to 60% by weight, preferably 15 to 30% by weight, relative to said dispersant phase. The polymer composition thus obtained is used as a masterbatch for preparing further polymer compositions according to the present invention, preferably in a masterbatch concentration of 0.1 to 5% by weight, more preferably 0.3 to 3% by weight, even more preferably 0.5 to 2.5% by weight of the total final composition. Thus, in step b) of the process, the marker is dispersed in an amount of 10 to 60% by weight, preferably 15 to 30% by weight, relative to the dispersion step, and the process comprises a further step c) in which the composition obtained in step b) is used as a masterbatch in a further polymer composition, in a concentration of 0.1 to 5% by weight, preferably 0.5 to 2.5% by weight, relative to the weight of the final composition.

[0070] The polymer composition obtained from said masterbatch may be obtained by techniques known to those skilled in the art, such as extrusion or dry blending. In the preparation of the polymer composition, the masterbatch is advantageously used in the absence of moisture, for example by drying as described above or under a stream of inert gas.

[0071] The polymer compositions according to the invention are particularly suitable for use in injection molding and thermoforming, as well as fiber spinning and film formation by methods known to those skilled in the art. The resulting molded articles may be subjected to hot annealing at temperatures between 60 and 150°C.

[0072] For example, the polymer compositions according to the invention are particularly suitable for the production of disposable cutlery, plates and cups, rigid containers, beverage dispenser capsules, preferably for hot beverages, caps and lids, packaging for food that can be heated in a conventional microwave oven, foam moulded articles, preferably obtained by extrusion or injection moulding, fibres, films or sheets consisting of one or more layers comprising the composition according to the invention. Therefore, biodegradable and compostable articles, such as those described above, comprising the compositions described above are also an object of the present invention.

[0073] The polymer composition according to the invention is preferably biodegradable and compostable according to UNI EN 13432. According to one aspect of the invention, molded articles obtained from said composition are rapidly biodegradable under industrial composting conditions, more preferably in home composting according to standard UNI 11355.

[0074] The present invention further relates to a method for tracking biodegradable polymer compositions, comprising the steps of preparing the molded article described above and subjecting the molded article to detection of photoactive components using a spectrofluorometer, preferably a spectrofluorometer having two monochromators with continuously adjustable slits for adjusting the spectral resolution and intensity of the fluorescent signal. For this purpose, a spectrofluorometer equipped with a light source consisting of an ozone-free xenon arc lamp (Po = 150 W) with a continuous light source in the 200-800 nm range focused on the input slit of the excitation monochromator may be used. Using a device based on two Czerny-Turner monochromators, incident light can be scattered by a reflection grating. Optical spectra can be obtained by rotating the grating and recording the intensity values at each wavelength. The input and output ports of each monochromator include continuously adjustable slits for controlling the spectral resolution and intensity of the fluorescent signal recorded by the photomultiplier tube. A solid sample holder attached to an adjustable goniometer can be used to test polymeric products in the form of films 1-3 mm thick containing photoactive components. The sample configuration with a 60° angle between the incident and specularly reflected beams prevents the excitation beam from entering the emission slit, thereby avoiding interference with light scattered by the sample under test.

[0075] More generally, the above items can be detected using optical sorters equipped with appropriate systems for VIS (visible wavelength range) and NIR (near infrared wavelength) spectroscopic sensors to detect optical excitation (broad spectrum lamps, laser diodes) in the 500-600 nm range and optical emission radiation (>570 nm).

[0076] The compositions and preparation processes according to the present invention are illustrated, without limitation, in the following examples. [Example]

[0077] Example Comparative Example 1 It has 47 mole % aromatic units relative to the dicarboxylic acid component, a MFR of 97 g / 10 min (measured at 190 °C according to standard ISO 1133-1, weight 2.16 kg, melt density 1.05 g / cm 3 Poly(1,4-butylene adipate-co-1,4-butylene terephthalate) (PBAT) having the following structure was subjected to an injection molding process to obtain a sheet with dimensions of 70x80x1 mm under the following conditions: · Injection temperature: 180°C Injection pressure: 750 bar The resulting sheets were subjected to detection of the photoactive component using a spectrofluorometer according to the method described below in Example 2. The spectra were compared with the spectra of the sample sheets of Example 2, as reported in Figure 1.

[0078] Example 2 A biodegradable and compostable polymer composition according to the present invention comprising a diacid diol polyester (i) and a marker (iv) was prepared as follows. Marker (iv) containing Rhodamine B incorporated in zeolite with pore sizes between 4 and 12 Å was dried in a vacuum oven at 150°C for 2 hours until a moisture content of approximately 320 ppm was obtained. 85 g of the marker was extracted with a zeolite having 47 mol% aromatic units relative to the dicarboxylic acid moiety, a MFR of 97 g / 10 min (measured at 190°C according to standard ISO 1133-1), a weight of 2.16 kg, and a melt density of 1.05 g / cm. 3 The mixture was physically mixed with poly(1,4-butylene adipate-co-1,4-butylene terephthalate) (PBAT) having the formula (I), further dried at 90°C for 2 hours, and fed into a Haake twin-screw extruder (barrel: 22 x 125 mm, 1-hole circular die with a 3 mm diameter) forming part of a spaghetti extrusion line equipped with a water bath, dryer, and cutter, and operated under the following conditions: -rpm:100 -Flow rate: 35rpm -Thermal profile: 80-140-130-100°C The resulting composition consisted of 83% by weight of PBAT and 17% by weight of marker.

[0079] 0.5 PHR of the resulting composition was then physically mixed with the biodegradable and compostable polyester PBAT used in Comparative Example 1. The granule mixture was subjected to an injection molding process to obtain a sheet with dimensions of 70x80x1 mm under the following conditions: · Injection temperature: 180°C Injection pressure: 750 bar

[0080] The marker was present in the polymer composition in an amount of 0.085 wt %. The resulting sheets were subjected to detection of the photoactive component using a spectrofluorometer, as described below. The spectra reported in Figure 1 are the average of multiple spectra for each sample sheet of Comparative Example 1 and Example 2. The average values for emission (575 nm) are 231 cps / μA (Comparative Example 1) and 1276 cps / μA (Example 2), respectively.

[0081] Experiment: The excitation wavelength was set to 500 nm, i.e., lower than the maximum excitation peak, to avoid overlap of the excitation and emission signals. To obtain a clearly detectable signal within the linear range of the PMT detector, the apertures of the front input and output slits were calibrated to boost the signal. To ensure comparable scales, the 5 nm bandwidth was kept the same in Comparative Example 1 and Comparative Example 2. Dark offset was enabled. The PMT correction signal S1C and the lamp correction reference signal R1C were included in the acquisition panel to calculate S1C / R1C, taking into account the PMT sensitivity and the intensity fluctuations of the Xe lamp light source, respectively. A 1-second accumulation time was set to obtain an averaged signal.

[0082] Comparative Example 3 It consists of 79% PBTA with 47 mole % aromatic units relative to the dicarboxylic acid component, 20% polylactic acid (PLA) Ingeo 4043D, and 1% additives. It has a MFR of 3.8 g / 10 min (measured at 190 °C according to standard ISO 1133-1), a weight of 2.16 kg, and a melt density of 1.11 g / cm. 3 The biodegradable and compostable polymer composition having the formula (I) was converted via a film blowing process to obtain a film with a thickness of 20±5 μm under the following conditions: -Thermal profile: 140-185-160x2-155°C The resulting film was subjected to spectrofluorescence analysis according to the method described below in Example 4. The spectrum was compared with that of the sample film of Example 4, as reported in FIG.

[0083] Example 4 A biodegradable and compostable polymer composition according to the present invention comprising a diacid diol polyester (i) and a marker (iv) was prepared as follows. Marker (iv) containing Rhodamine B incorporated in zeolite with pore sizes between 4 and 12 Å was dried in a vacuum oven at 150°C for 2 hours until a moisture content of approximately 320 ppm was obtained. 85 g of the marker was extracted with a zeolite having 47 mol% aromatic units relative to the dicarboxylic acid moiety, a MFR of 97 g / 10 min (measured at 190°C according to standard ISO 1133-1), a weight of 2.16 kg, and a melt density of 1.05 g / cm. 3 The mixture was physically mixed with poly(1,4-butylene adipate-co-1,4-butylene terephthalate) (PBAT) having the formula (I), further dried at 90°C for 2 hours, and fed into a Haake twin-screw extruder (barrel: 22 x 125 mm, 1-hole circular die with a 3 mm diameter) forming part of a spaghetti extrusion line equipped with a water bath, dryer, and cutter, and operated under the following conditions: -rpm:100 -Flow rate: 35rpm -Thermal profile: 80-140-130-100°C The resulting composition consisted of 83% by weight of PBAT and 17% by weight of marker.

[0084] 0.5 PHR of the resulting composition was then physically mixed with the biodegradable and compostable polyester composition containing 79% PBTA and 20% PLA used in Comparative Example 3. The granule mixture was subjected to a film-blowing process to obtain a film with a thickness of 20±5 μm under the following conditions: Thermal profile: 140-185-160x2-155°C

[0085] The marker was present in the polymer composition in an amount of 0.085 wt %. The resulting films were subjected to spectrofluorometric detection of the photoactive components, as described below. The spectra reported in Figure 2 are the average of multiple spectra for each sample of Comparative Example 3 and Example 4. The average values for emission (580 nm) are 10,842 cps / μA (Comparative Example 3) and 66,237 cps / μA (Example 4), respectively.

[0086] Experiment: The excitation wavelength was set to 550 nm, i.e., lower than the maximum excitation peak, to avoid overlap of the excitation and emission signals. To obtain a clearly detectable signal within the linear range of the PMT detector, the apertures of the front input and output slits were calibrated to boost the signal. To ensure a comparable scale, the 4 nm bandwidth was kept the same in Comparative Example 3 and Comparative Example 4. Dark offset was enabled. The PMT correction signal S1C and the lamp correction reference signal R1C were included in the acquisition panel to calculate S1C / R1C, taking into account the PMT sensitivity and the intensity fluctuations of the Xe lamp light source, respectively. A 1-second accumulation time was set to obtain an averaged signal.

[0087] Comparative Example 5 A biodegradable and compostable polymer composition containing 43.9% polybutylene succinate (PBS), 21.2% polylactic acid (PLA) Ingeo 4043D, 0.07% Carbodilite HMV-5CA-LC, 0.3% Crodammide ER beads, and 34.53% talc Ecofil (average particle size 7800 nm) from Imi Fabi was subjected to an injection molding process to obtain a sheet with dimensions of 70 x 80 x 1 mm under the following conditions: · Injection temperature: 220°C Injection pressure: 750 bar The resulting sheets were subjected to detection of the photoactive component using a spectrofluorometer according to the method described below in Example 6. The spectra were compared with the spectra of the sample sheets of Example 6, as reported in FIG.

[0088] Example 6 A biodegradable and compostable polymer composition according to the present invention comprising a diacid diol polyester (i) and a marker (iv) was prepared as follows. Marker (iv) containing Rhodamine B incorporated in zeolite with pore sizes between 4 and 12 Å was dried in a vacuum oven at 150°C for 2 hours until a moisture content of approximately 320 ppm was obtained. 85 g of the marker was extracted with a zeolite having 47 mol% aromatic units relative to the dicarboxylic acid moiety, a MFR of 97 g / 10 min (measured at 190°C according to standard ISO 1133-1), a weight of 2.16 kg, and a melt density of 1.05 g / cm. 3 The mixture was physically mixed with poly(1,4-butylene adipate-co-1,4-butylene terephthalate) (PBAT) having the formula (I), further dried at 90°C for 2 hours, and fed into a Haake twin-screw extruder (barrel: 22 x 125 mm, 1-hole circular die with a 3 mm diameter) forming part of a spaghetti extrusion line equipped with a water bath, dryer, and cutter, and operated under the following conditions: -rpm:100 -Flow rate: 35rpm -Thermal profile: 80-140-130-100°C The resulting composition consisted of 83% by weight of PBAT and 17% by weight of marker.

[0089] 0.3 PHR of the resulting composition was then physically mixed with the biodegradable and compostable polymer composition used in Comparative Example 5. The granule mixture was subjected to an injection molding process to obtain a sheet with dimensions of 70x80x1 mm under the following conditions: · Injection temperature: 220°C Injection pressure: 750 bar

[0090] The marker was present in the polymer composition in an amount of 0.051 wt %. The resulting sheets were subjected to detection of the photoactive component using a spectrofluorometer, as described below. The spectra reported in Figure 3 are the average of multiple spectra for each sample of Comparative Example 5 and Example 6. The average values for emission (580 nm) are 51,969 cps / μA (Comparative Example 5) and 81,050 cps / μA (Example 6), respectively.

[0091] Experiment: The excitation wavelength was set to 500 nm, i.e., lower than the maximum excitation peak, to avoid overlap of the excitation and emission signals. To obtain a clearly detectable signal within the linear range of the PMT detector, the apertures of the front input and output slits were calibrated to boost the signal. To ensure a comparable scale, the 5 nm bandwidth was kept the same in Comparative Example 5 and Example 6. Dark offset was enabled. The PMT correction signal S1C and the lamp correction reference signal R1C were included in the acquisition panel to calculate S1C / R1C, taking into account the PMT sensitivity and the intensity fluctuations of the Xe lamp light source, respectively. A 1-second accumulation time was set to obtain an averaged signal.

Claims

1. At least one diol dioxide polyester (i), Optionally, one or more polyhydroxyalkanoates (ii), Optionally, one or more fillers (iii), At least one marker (iv) containing rhodamine B incorporated into a zeolite with a pore size of 4 Å to 12 Å and A biodegradable and compostable polymer composition containing [the specified element].

2. The polymer composition according to claim 1, wherein each of components (i) to (iii) or a mixture thereof is characterized by a transmittance of more than 50% in the range of 900 nm to 1650 nm.

3. The polymer composition according to claim 1, wherein the diol dioxide polyester (i) is an aliphatic polyester.

4. The polymer composition according to claim 3, wherein the aliphatic polyester is present in an amount of 5% to 80% by weight relative to the total weight of the composition.

5. The polymer composition according to claim 1, wherein the diol dioxide polyester is an aliphatic-aromatic polyester.

6. The polymer composition according to claim 5, wherein the aliphatic-aromatic polyester is present in an amount of 5% to 99.9% by weight relative to the total weight of the composition.

7. The polymer composition according to claim 1, comprising 1% to 80% by weight of polyhydroxyalkanoate (ii) based on the total weight of the composition.

8. The polymer composition according to claim 1, wherein the polyhydroxyalkanoate (ii) is a lactic acid polyester.

9. The polymer composition according to claim 1, wherein the filler (iii) has an average particle size greater than 700 nm, preferably an average particle size of >800 nm, and more preferably an average particle size of >1 μm.

10. The polymer composition according to claim 1, wherein the filler (iii) is talc.

11. The polymer composition according to claim 1, wherein marker (iv) is present in an amount of 0.01% by weight or more, preferably 0.1% by weight or more, relative to the total weight of the composition.

12. The polymer composition according to claim 1, further comprising starch.

13. A compostable molded article comprising the polymer composition according to any one of claims 1 to 12.

14. a) A step of drying a marker (iv) containing rhodamine B incorporated into a zeolite having a pore size of 4 Å to 12 Å until a water content of less than 2000 ppm is obtained, preferably <1500 ppm, more preferably <1000 ppm; b) A step of incorporating the marker (dispersed phase) into one or more of components (i) to (iii) of the biodegradable polymer composition (dispersant phase) by extrusion molding, preferably at a peak temperature of 120°C to 220°C. A process for preparing the biodegradable and compostable polymer composition according to claim 1, comprising:

15. The process according to claim 14, further comprising step b) in which the marker is dispersed in an amount of 10% to 60% by weight, preferably 15% to 30% by weight, relative to the dispersant phase, and the composition obtained in step b) is used as a masterbatch in a further polymer composition at a concentration of 0.1% to 5% by weight, preferably 0.5% to 2.5% by weight, relative to the weight of the final composition, the process according to claim 14.

16. A method for tracking a biodegradable and compostable polymer composition, comprising the steps of: manufacturing a molded article according to claim 13; and subjecting the molded article to the detection of photoactive components using a spectrofluorometer.

17. Use of the biodegradable and compostable polymer composition according to claim 1 for tracking molded articles containing it in a waste sorting process.

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