Molded article comprising barrier label

Abstract

The present invention relates to a biodegradable molded or thermoformed article for food packaging comprising a label having barrier properties.

Description

Technical Field

[0001] The present invention relates to a biodegradable molded or thermoformed article for food packaging, comprising a label having volatile substance and gas barrier properties. Background Art

[0002] In the field of food packaging, one of the main challenges is to ensure very good mechanical properties and low deformation, especially for applications involving high temperatures during use, such as cutlery, plates, capsules or containers.

[0003] Diacid-diol polyesters are widely used in this field due to their excellent mechanical and processing properties, as well as the possibility of obtaining biodegradable products.

[0004] However, some volatile substances may be formed as by-products in the above-mentioned synthesis process, which includes the condensation reaction between the diol and the diacid or its derivatives. In the case of the diacid-diol polyester derived from 1,4-butanediol, possible by-products may be tetrahydrofuran (THF) and butenol (BOL) produced by the following reaction:

[0005] Dehydration of 1,4-butanediol during polyester synthesis

[0006] O(CH2)4OH→THF+H2O

[0007] O(CH2)4OH→BOL+H2O

[0008] Degradation of terminal hydroxybutyl groups formed during the synthesis of the polyester itself ('backbite' reaction)

[0009] Polyester-C(O)O(CH2)4OH→THF+Polyester-C(O)OH

[0010] Because these volatile substances are present as by-products, the direct use of these materials in food contact applications must meet specific migration limits. In this regard, for example, Regulation (EU) No. 10 / 2011 of 14 January 2011 on plastic materials and articles intended to come into contact with foodstuffs stipulates a 0.6 mg / kg limit from packaging to food. 食品 The specific migration limit of THF.

[0011] Food packaging applications also require low permeability to gases, particularly oxygen, carbon dioxide and water vapor, in order to maintain the organoleptic properties of the food and ensure its preservation.

[0012] WO 2017 / 148931 Al discloses a method of pre-treating polyester to remove THF, but this does not ensure the removal of other volatiles or impart gas barrier properties to the polyester subjected to the method.

[0013] Therefore, in order to use such polyesters in food packaging applications, they must be combined with a barrier to volatiles and gases without affecting the mechanical properties and biodegradability of the final product.

[0014] For example, WO2019 / 002780 discloses a biodegradable article for food packaging, which comprises a biodegradable support to which a biodegradable film is adhered by in-mold labeling.

[0015] Taking this problem as a starting point, it has now been found that, surprisingly, it is possible to obtain biodegradable moulded or thermoformed articles for food packaging which have improved barrier properties. Summary of the invention

[0016] In particular, the object of the present invention is a biodegradable molded or thermoformed article for food packaging, the article comprising a body and a barrier label, wherein:

[0017] i. the body comprises at least one biodegradable diacid-diol polyester comprising 1,4-butanediol dicarboxylate units;

[0018] ii. The barrier label comprises at least one biodegradable support and at least one coating layer, the biodegradable support consisting of a mixture comprising polyhydroxyalkanoate and at least one aliphatic and / or aliphatic-aromatic polyester;

[0019] wherein the label (ii) is attached to the body (i) by in-mould labelling of the food contact portion. When so positioned, the label (ii) confers a higher barrier to THF permeation of food on the article than in the absence of the label, advantageously two times more, preferably 5 times more, more preferably 10 times more, even more preferably 15 times more and up to 100 times, for example 50 times more.

[0020] In molded or thermoformed articles for food packaging, a portion of the THF contained in the bulk generally diffuses from the interior into the food, while another portion of the THF diffuses from the article outward, away from the food.

[0021] In order to evaluate the THF permeation barrier effect of the barrier label (ii) on the food, it may be advantageous to use an experimental method which allows all THF contained in the bulk to migrate only into the food, in order to take into account the worst case scenario.

[0022] For example, a THF source (e.g., particles of poly(1,4-butylene glycol succinate)) is introduced into a sealed bag made of barrier label (ii). The sealed bag is placed in an aluminum bag containing a food product (e.g., a commercial blend of ground roast coffee for a home espresso machine).

[0023] As a comparison, the same amount of THF source was dispersed in an aluminum bag containing the commercial blend of ground roast coffee without a sealed bag made of barrier label (ii).

[0024] In both cases, the weight ratio between THF source and coffee powder was 0.3.

[0025] After conditioning the aluminum bag in an oven at T = 60°C for 10 days, the amount of THF migrated into the coffee powder was measured to evaluate the barrier performance of the label to THF and compared with the amount of THF migrated into the coffee powder in the absence of a sealed bag made of barrier label (ii).

[0026] For example, a 4-6 g aliquot of a coffee powder sample recovered from an aluminum bag was measured for THF content as described in WO 2017 / 148931 Al.

[0027] The biodegradable molded or thermoformed articles of the present invention are used for trays, cups, rigid containers, beverage dispensing capsules, caps, lids and food containers that can be heated in conventional ovens and microwave ovens. Preferably, the biodegradable molded or thermoformed articles of the present invention can be used for beverage dispensing capsules, preferably for hot beverages.

[0028] The biodegradable molded or thermoformed article of the present invention is biodegradable according to standard EN 13432. Preferably, the biodegradable molded or thermoformed article of the present invention is biodegradable in industrial composting according to standard EN 13432. According to another aspect of the present invention, the biodegradable molded or thermoformed article of the present invention is biodegradable in home composting according to standard EN11355.

[0029] The biodegradable molded or thermoformed article according to the present invention can be obtained by injection molding, blow molding, compression molding and thermoforming. Preferably, the biodegradable molded or thermoformed article according to the present invention is obtained by injection molding. DETAILED DESCRIPTION

[0030] The biodegradable molded or thermoformed article of the present invention comprises a main body (i) and a barrier label (ii), wherein the label (ii) is attached to the main body (i) by an in-mold labeling method of the portion in contact with food. In a preferred embodiment, the biodegradable molded or thermoformed article of the present invention comprises a main body (i) and a barrier label (ii), wherein the label (ii) is attached to the main body (i) by an in-mold labeling method of the portion in contact with food.

[0031] In another preferred embodiment, the biodegradable molded or thermoformed article according to the present invention comprises a main body (i) and two barrier labels (ii), wherein one of the two labels (ii) is adhered to the main body (i) by in-mold labeling of the part in contact with the food, and the other label (ii) is adhered to the main body (i) by in-mold labeling of the outer part.

[0032] The label (ii) may be adhered to the main body (i) from the coating layer side or from the support side. Preferably, the label (ii) is adhered to the main body (i) from the support side.

[0033] In-mold labeling (IML) or in-mold decoration refers to the use of labels during the production of molded or thermoformed articles. With in-mold labeling, the label becomes an integral part of the molded or thermoformed article, avoiding undesirable effects such as peeling or delamination, thereby avoiding the risk that the label may be removed from the body.

[0034] The label (ii) is adhered to the portion of the body (i) of the molded article of the invention that comes into contact with the food. A label of sufficient size to cover the entire inner surface of the molded article is placed on the male shell of the mold and introduced by injection of the molten body (i) composition by the action of high pressure applied to the surface.

[0035] The body (i) of the biodegradable molded or thermoformed article of the present invention comprises at least one diacid-diol polyester comprising 1,4-butanediol dicarboxylate units. The diacid-diol polyester comprising 1,4-butanediol dicarboxylate units is obtained by condensing 1,4-butanediol with at least one diacid, ester or salt thereof. The diacid-diol polyester comprising 1,4-butanediol dicarboxylate units is selected from aliphatic and aliphatic-aromatic polyesters.

[0036] In the case of aliphatic-aromatic polyesters, this preferably comprises:

[0037] (a) a dicarboxylic acid component, relative to the total dicarboxylic acid component, comprising:

[0038] a1) 30 to 70 mol %, preferably 40 to 60 mol %, of units derived from at least one aromatic dicarboxylic acid;

[0039] a2) 70 to 30 mol %, preferably 60 to 40 mol %, of units derived from at least one saturated aliphatic dicarboxylic acid;

[0040] a3) 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0041] b) a diol component, relative to the total diol component, comprising:

[0042] (b1) 95 to 100 mol %, preferably 97 to 100 mol %, of units derived from 1,4-butanediol;

[0043] b2) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from another saturated aliphatic diol other than b1);

[0044] b3) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from unsaturated aliphatic diols.

[0045] The aromatic dicarboxylic acid of component a1 is preferably selected from aromatic dicarboxylic acids of the phthalic acid type, preferably terephthalic acid or isophthalic acid, more preferably terephthalic acid, and heterocyclic aromatic dicarboxylic acid compounds, preferably 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, more preferably 2,5-furandicarboxylic acid, their esters, salts and mixtures thereof.

[0046] In a preferred embodiment, the aromatic dicarboxylic acid comprises:

[0047] - 1 mol % to 99 mol %, preferably 5 mol % to 95 mol %, and more preferably 10 mol % to 80 mol % of terephthalic acid, an ester or a salt thereof;

[0048] 99 to 1 mol %, preferably 95 to 5 mol % and more preferably 90 to 20 mol % of 2,5-furandicarboxylic acid, an ester or a salt thereof.

[0049] The saturated aliphatic dicarboxylic acid of component a2 is preferably selected from C2-C24, preferably C4-C13, more preferably C4-C11 saturated aliphatic dicarboxylic acids, their C1-C24, more preferably C1-C4 alkyl esters, their salts and mixtures thereof. Preferably, the saturated aliphatic dicarboxylic acid is selected from: succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dioic acid, dodecanedioic acid, tridecanedioic acid and C1-C24 alkyl esters thereof. In a preferred embodiment of the present invention, the saturated aliphatic dicarboxylic acid comprises succinic acid, adipic acid, azelaic acid, sebacic acid and mixtures thereof.

[0050] The unsaturated aliphatic dicarboxylic acid of component a3 is preferably selected from itaconic acid, fumaric acid, 4-methylene-pimelic acid, 3,4-bis(methylene)azelaic acid, 5-methylene-azelaic 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, the mixture comprising at least 50 mol %, preferably greater than 60 mol %, more preferably greater than 65 mol % of itaconic acid, its C1-C24, preferably C1-C4 ester. More preferably, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid.

[0051] As regards the saturated aliphatic diols of component b2, these are preferably selected from 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 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-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitol, dianhydromannitol, dianhydroiditol, cyclohexanediol, dialkylene glycols and polyalkylene glycols having a molecular weight of 100 to 4000, such as polyethylene glycol, polypropylene glycol and mixtures thereof.

[0052] As regards the unsaturated aliphatic diols of component b3, they are 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, 3-hexene-1,6-diol.

[0053] Preferably, the diol component b comprises one or more diols selected from 1,2-ethylene glycol and 1,3-propylene glycol in addition to 1,4-butanediol. More preferably, the diol component comprises 1,4-butanediol.

[0054] In the case of aliphatic polyesters, this preferably comprises:

[0055] c) a dicarboxylic acid component, relative to the total dicarboxylic acid component, comprising

[0056] (c1) 95 to 100 mol % of units derived from at least one aliphatic dicarboxylic acid;

[0057] (c2) 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0058] d) a diol component, relative to the total diol component, comprising:

[0059] d1) 95 to 100 mol %, preferably 97 to 100 mol %, of units derived from 1,4-butanediol;

[0060] d2) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from further saturated aliphatic diols other than b1);

[0061] d3) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from unsaturated aliphatic diols.

[0062] The saturated aliphatic dicarboxylic acids in component c1 are preferably selected from saturated C2-C24, preferably C4-C13, more preferably C4-C11 dicarboxylic acids, their C1-C24, preferably C1-C4 alkyl esters, their salts and mixtures thereof. Preferably, the saturated aliphatic dicarboxylic acids are selected from succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, hexadecanedioic acid, octadecanedioic acid and their C1-C24 alkyl esters.

[0063] The unsaturated aliphatic dicarboxylic acid in component c2 is preferably selected from itaconic acid, fumaric acid, 4-methyl-pimelic acid, 3,4-bis(methylene)azelaic acid, 5-methylene-azelaic 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, the mixture comprising at least 50 mol %, preferably greater than 60 mol %, more preferably greater than 65 mol % of itaconic acid and its C1-C24, preferably C1-C4 esters. More preferably, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid.

[0064] As regards the saturated aliphatic diols in component d2, these are preferably selected from 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 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-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitan, dianhydromannitol, dianhydroiditol, cyclohexanediol, dialkylene glycols and polyalkylene glycols having a molecular weight of 100 to 4000, such as polyethylene glycol, polypropylene glycol, and mixtures thereof.

[0065] As regards the unsaturated aliphatic diols in component d3, these are 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-hexyne-1,6-diol, cis-3-hexene-1,6-diol, trans-3-hexene-1,6-diol, 3-hexyne-1,6-diol.

[0066] Preferably, the diol component d comprises one or more diols selected from 1,2-ethylene glycol and 1,3-propylene glycol in addition to 1,4-butanediol. More preferably, the diol component comprises 1,4-butanediol.

[0067] In a preferred embodiment, the diacid-diol polyester comprising 1,4-butanediol dicarboxylate units is preferably selected from the group consisting of: poly(1,4-butanediol succinate), poly(1,4-butanediol adipate), poly(1,4-butanediol azelaate), poly(1,4-butanediol sebacate), poly(1,4-butanediol tridecanoate), poly(1,4-butanediol azelaate-co-1,4-butanediol succinate), poly(1,4-butanediol adipate-co-1,4-butanediol succinate), poly(1,4-butanediol adipate-co-1,4-butanediol 2,5-furan dicarboxylate), poly(1,4-butanediol sebacate-co-1,4-butanediol 2,5-furan dicarboxylate), poly(1,4 1,4-Butanediol azelaic acid ester-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,4-butanediol tridecanoic acid ester-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,4-butanediol succinate-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,2-ethylene glycol adipate-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,2-ethylene glycol sebacate-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,2-ethylene glycol azelaic acid ester-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,2-ethylene glycol tridecanoic acid ester-co-1,4-butanediol 2,5-furandicarboxylate), poly(1,2 1,4-Butanediol succinate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,4-butanediol adipate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol sebacate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol azelaate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol tridecanoate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol succinate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol terephthalate), poly(1,4-butanediol 2,5-furandicarboxylate) Ester), poly(1,2-ethylene terephthalate-co-1,4-butylene terephthalate), poly(1,3-propylene terephthalate-co-1,4-butylene terephthalate), poly(1,4-butylene terephthalate-co-1,4-butylene terephthalate-2,5-furan dicarboxylate), poly(1,2-ethylene terephthalate-co-1,4-butylene terephthalate-2,5-furan dicarboxylate), poly(1,3-propylene terephthalate-co-1,4-butylene terephthalate-2,5-furan dicarboxylate), poly(1,2-ethylene terephthalate-co-1,4-butylene terephthalate-2,5-furan dicarboxylate), poly(1,4-butylene terephthalate-co-1,2-ethylene terephthalate-2,1,4-Butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol terephthalate), poly(1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelaic acid-co-1,4-butanediol terephthalate), poly(1,4-butanediol tridecanoate-co-1,4-butanediol terephthalate), poly(1,4-butanediol succinate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelaic acid-co-1,4-butanediol terephthalate), poly(1,4-butanediol tridecanoate-co-1,4-butanediol terephthalate), poly(1,4-butanediol succinate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelaic acid-co-1,4-butanediol ester-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol azelaic acid-co-1,4-butanediol terephthalate), poly(1,4-butanediol succinate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol succinate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelaic acid-co-1,4-butanediol succinate-co-1,4-butanediol terephthalate), and block or random copolymers thereof. Preferably, the diacid-diol polyester comprising 1,4-butanediol dicarboxylate units is preferably selected from poly(1,4-butanediol succinate), poly(1,4-butanediol azelate-co-1,4-butanediol succinate), poly(1,4-butanediol adipate-co-1,4-butanediol terephthalate).

[0068] The diacid-diol polyesters containing 1,4-butanediol dicarboxylate units in the main body (i) can also advantageously contain repeating 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 suitable 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 can be inserted into the chain as such or as prepolymers / oligomers, or they can also be pre-reacted with diacids or diols.

[0069] Long chain molecules with two functional groups, including those with non-terminal functional groups, may also be added in an amount not exceeding 10 mol % relative to the total moles of the dicarboxylic acid component. Examples are dimer acids, ricinoleic acid and acids with epoxy functional groups and polyoxyethylenes with molecular weights between 200 and 10,000.

[0070] The diamines, amino acids and amino alcohols may also be present in percentages up to 30 mol % relative to the total moles of the dicarboxylic acid component.

[0071] In the preparation process of the diacid-diol polyester containing 1,4-butanediol dicarboxylate units of the main body (i), one or more multifunctional molecules can also be advantageously added in an amount of 0.1-3 mol% of the total moles of the dicarboxylic acid component to obtain a branched product. Examples of these molecules are glycerol, pentaerythritol, trimethylolpropane, citric acid, dipentaerythritol, monoanhydrosorbitol, monoanhydromannitol, triglycerides, polyglycerols, etc.

[0072] The molecular weight Mn of the diacid-diol polyester containing 1,4-butanediol dicarboxylate units of the body (i) is preferably ≥ 20000, more preferably ≥ 40000. Regarding the polydispersity index Mw / Mn of the molecular weight, it is preferably 1.5 to 10, more preferably 1.6 to 5, even more preferably 1.8 to 3.5.

[0073] Molecular weights Mn and Mw can be measured by gel permeation chromatography (GPC). The determination can be carried out with a chromatography system maintained at 40°C, using a set of two columns in series (particle size 5 μm and 3 μm, with mixed porosity), a refractive index detector, chloroform as eluent (flow rate 0.5 ml / min) and using polystyrene as a reference standard.

[0074] The melt flow rate (MFR) of the diacid-diol polyester containing 1,4-butanediol dicarboxylate units of the main body (i) is preferably 500-1 g / 10 min, more preferably 100-3 g / 10 min, even more preferably 15-3 g / 10 min (measured according to ISO 1133-1 "Plastics - Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics - Part 1: Standard method" at 190°C / 2.16 kg).

[0075] The terminal acid group content of the diacid-diol polyester comprising 1,4-butanediol dicarboxylate units of body (i) is preferably from 15 to 160 meq / kg, more preferably from 20 to 100 meq / kg, even more preferably from 25 to 70 meq / kg.

[0076] The content of terminal acid groups can be measured as follows: 1.5-3 g of polyester is placed in a 100 ml conical flask together with 60 ml of chloroform. After the polyester is completely dissolved, 25 ml of 2-propanol is added and 1 ml of deionized water is added immediately before analysis. The resulting solution is titrated with a pre-standardized ethanolic solution of NaOH. The equivalence point of the titration is determined using a suitable indicator, such as a glass electrode for acid-base titration in non-aqueous solvents. The terminal acid group content is calculated based on the consumption of the NaOH solution in ethanol according to the following equation:

[0077]

[0078] in:

[0079] Veq = ml of NaOH solution in ethanol at the equivalence point of the sample titration;

[0080] Vb = ml of NaOH solution in ethanol required to reach pH 9.5 in the blank titration;

[0081] T = concentration of NaOH solution in ethanol, expressed in mol / L;

[0082] P = sample weight in grams.

[0083] Preferably, the diacid-diol polyester comprising 1,4-butanediol dicarboxylate units of the main body (i) exhibits an intrinsic viscosity greater than 0.3 dl / g, preferably 0.3-2 dl / g, more preferably 0.4-1.1 dl / g (measured in a CHCl3 solution with a concentration of 0.2 g / dl at 25°C using an Ubbelohde viscometer).

[0084] The diacid-diol polyesters comprising 1,4-butanediol dicarboxylate units of the subject (i) are biodegradable. For the purposes of the present invention, biodegradable polyesters are understood to be biodegradable polymers according to standard EN 13432.

[0085] The diacid-diol polyesters comprising 1,4-butanediol dicarboxylate units of the subject (i) can be synthesized according to any method known in the prior art. In particular, they can be advantageously obtained by polycondensation.

[0086] Advantageously, the synthesis process can be carried out in the presence of a suitable catalyst. Suitable catalysts include organometallic tin compounds, such as stannic acid derivatives, titanium compounds, such as n-butyl titanate, aluminum compounds, such as triisopropylaluminum, antimony and zinc and zirconium compounds and mixtures thereof.

[0087] Examples of synthetic methods that can be advantageously used to prepare polyesters are disclosed in international patent applications WO 2016 / 050963 Al and WO 2016 / 050962 Al. In addition to the diacid-diol polyester, the composition of the body (i) of the article of the invention may further optionally comprise 0% to 5% by weight, more preferably 0.05% to 4% by weight, even more preferably 0.1% to 3% by weight of at least one crosslinker and / or chain extender relative to the total mixture.

[0088] The crosslinking agent and / or chain extender improves the hydrolytic stability and is selected from difunctional and / or polyfunctional compounds with isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride, divinyl ether groups and mixtures thereof. Preferably, the crosslinking agent and / or chain extender comprises at least one difunctional and / or polyfunctional compound with epoxide or carbodiimide groups.

[0089] Preferably, the crosslinker and / or chain extender comprises at least one difunctional and / or polyfunctional compound carrying isocyanate groups. More preferably, the crosslinker and / or chain extender comprises at least 25% by weight of one or more difunctional and / or polyfunctional compounds carrying isocyanate groups. Particularly preferred are mixtures of difunctional and / or polyfunctional compounds carrying isocyanate groups and difunctional and / or polyfunctional compounds carrying epoxide groups, even more preferably at least 75% by weight of difunctional and / or polyfunctional compounds carrying isocyanate groups.

[0090] Preferably, the difunctional and polyfunctional compounds carrying isocyanate groups are selected from 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-cyclohexyl diisocyanate, 1-methyl-2,6-cyclohexyl diisocyanate, bis-(isocyanate cyclohexyl)methane, 2,4,6-toluene triisocyanate, 2,4,4-diphenyl ether triisocyanate, polymethylene-polyphenyl-polyisocyanate, methylene diphenyl diisocyanate, triphenylmethane triisocyanate, 3,3'-dithiolane-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 carrying an isocyanate group is 4,4-diphenylmethane-diisocyanate.

[0091] As far as difunctional and polyfunctional compounds carrying peroxide groups are concerned, these are preferably selected from benzoyl peroxide, lauroyl peroxide, isononanoyl peroxide, di(tert-butylperoxyisopropyl)benzene, tert-butyl peroxide, dicumyl peroxide, α,α′-di(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, di(4-tert-butylcyclohexyl)peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, di(2-ethylhexyl)peroxydicarbonate and mixtures thereof. The difunctional and polyfunctional compounds with carbodiimide groups preferably used in the composition of the article body (i) of the present invention are selected from poly(cyclooctylenecarbodiimide), poly(1,4-dimethylcyclohexylenecarbodiimide), poly(cyclohexylenecarbodiimide), poly(ethylenecarbodiimide), poly(butylenecarbodiimide), poly(isobutylenecarbodiimide), poly(nonylenecarbodiimide), poly(dodecylenecarbodiimide), poly(neopentylenecarbodiimide), poly(1,4-dimethylphenylenecarbodiimide), poly(2,2',6,6',tetraisopropyldiphenylenecarbodiimide) D), poly (2,4,6-triisopropyl-1,3-phenylenecarbodiimide) ( P-100), poly (2,6-diisopropyl-1,3-phenylenecarbodiimide) ( 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.

[0092] Examples of difunctional and polyfunctional compounds bearing epoxide groups which can be advantageously used in the composition of the body (i) of the article according to the invention are all polyepoxides from epoxidized oils and / or from styrene-glycidyl ether methyl methacrylate, glycidyl ether-methyl methacrylate, whose molecular weight ranges between 1000 and 10000 and the number of epoxides per molecule ranges from 1 to 30 and preferably from 5 to 25, the epoxides being selected from diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, diglycidyl ether, polyglycerol polyglycidyl ether, 1,2-butylene oxide, polyglycerol polyglycidyl ether, isoprene diepoxide, and alicyclic diepoxide, 1,4-cyclohexanedimethanol diglycidyl ether, glycidyl 2-methylphenyl ether, glycerol propoxy triglycidyl ether, 1,4-butanediol diglycidyl ether, sorbitol polyglycidyl ether, glycerol diglycidyl ether, tetraglycidyl ether of meta-xylene diamine and diglycidyl ether of bisphenol A and mixtures thereof.

[0093] In a particularly preferred embodiment of the present invention, the crosslinker and / or chain extender optionally present in the composition of the body (i) of the article of the present invention comprises a compound with isocyanate groups (preferably 4,4-diphenylmethane diisocyanate), and / or with carbodiimide groups, and / or with epoxide groups (preferably of the styrene-glycidyl ether-methyl methacrylate type).

[0094] In a particularly preferred embodiment of the present invention, the crosslinker and / or chain extender comprises a compound carrying epoxide groups of the styrene-glycidyl ether-methyl methacrylate type.

[0095] With difunctional and polyfunctional compounds bearing isocyanate, peroxide, carbodiimide, isocyanurate, oxazoline, epoxide, anhydride, divinyl ether groups, catalysts can also be used to increase the reactivity of the reactive groups. In the case of polyepoxides, preference is given to using fatty acid salts, even more preferably calcium stearate and zinc stearate.

[0096] In addition to the diacid-diol polyesters, the composition of the body of the article of the invention may be mixed with other polymers of synthetic or natural origin, whether biodegradable or not.

[0097] As regards the polymers of synthetic or natural origin, whether biodegradable or not, they are advantageously chosen from polyhydroxyalkanoates, vinyl polymers, diacid-diol polyesters identical or different to those previously described, polyamides, polyurethanes, polyureas, polycarbonates and mixtures thereof. In a particularly preferred form, said polymers may be blended in an amount of up to 80% by weight relative to the diacid-diol polyesters of subject (i) of the invention.

[0098] As far as polyhydroxyalkanoates are concerned, they may be present in an amount of 30% to 80% w / w, preferably 40% to 75% w / w, even more preferably 45% to 70% w / w of the total composition of body (i).

[0099] These polyhydroxyalkanoates are preferably selected from polyesters of lactic acid, poly-ε-caprolactone, polyhydroxybutyrate, polyhydroxybutyrate valerate, polyhydroxybutyrate propionate, polyhydroxybutyrate caproate, polyhydroxybutyrate decanoate, polyhydroxybutyrate dodecanoate, polyhydroxybutyrate hexadecanoate, polyhydroxybutyrate octadecanoate, poly 3-hydroxybutyrate-4-hydroxybutyrate. Preferably, the polyhydroxyalkanoate comprises at least 80% w / w of one or more lactic acid polyesters.

[0100] In a preferred embodiment, the lactic acid polyester is selected from poly L-lactic acid, poly D-lactic acid, poly DL lactic acid stereocomplex, copolymers containing more than 50 mol % of said lactic acid polyester, or mixtures thereof.

[0101] Particularly preferred are lactic acid polyesters containing at least 95% w / w of repeating units derived from L-lactic acid or D-lactic acid or a combination thereof, having a molecular weight Mw greater than 50,000 and a shear viscosity of 50-700 Pa.s, preferably 80-500 Pa.s (according to ASTM D3835 standard at T = 190 ° C, shear rate = 1000 s -1 , D=1mm, L / D=10).

[0102] In a particularly preferred embodiment of the present invention, the lactic acid polyester comprises at least 95% w / w of units derived from L-lactic acid, ≤5% w / w of repeating units derived from D-lactic acid, has a melting temperature of 135-175°C, a glass transition temperature (Tg) of 50-65°C and an MFR of 1-50 g / 10 min (measured at 190°C and 2.16 kg according to ASTM-D1238 standard).

[0103] Commercial examples of lactic acid polyesters having these properties include Ingeo TM Biopolymer brand products 4043D, 3251D, 6202D and Brand product L105.

[0104] Preferred vinyl polymers include polyethylene, polypropylene, their copolymers, polyvinyl alcohol, polyethylene vinyl acetate and polyethylene vinyl alcohol, polystyrene, chlorinated vinyl polymers, polyacrylates.

[0105] In addition to polyvinyl chloride, chlorinated ethylene-based polymers include polyvinylidene chloride, polyvinyl chloride, poly(vinyl chloride-vinyl acetate), poly(vinyl chloride-ethylene), poly(vinyl chloride-propylene), poly(vinyl chloride-styrene), poly(vinyl chloride-isobutylene), and copolymers in which polyvinyl chloride accounts for more than 50 mole percent. Such copolymers may be random, block or alternating.

[0106] As far as polyamides are concerned, these are preferably chosen from polyamide 6 and 6.6, polyamide 9 and 9.9, polyamide 10 and 10.10, polyamide 11 and 11.11, polyamide 12 and 12.12 and combinations thereof of the 6 / 9, 6 / 10, 6 / 11, 6 / 12 type and blends and copolymers thereof, both random and block.

[0107] Preferably, the polycarbonate is selected from polyalkylene carbonates, more preferably polyethylene carbonate, polypropylene carbonate, polybutylene carbonate, blends thereof and random and block copolymers.

[0108] Among the polyethers, preferred ones are selected from polyethylene glycol, polypropylene glycol, polybutylene glycol, copolymers thereof and blends thereof having a molecular weight of 70,000 to 500,000.

[0109] As far as polymers of natural origin are concerned, these are advantageously chosen from starch, chitin, chitosan, alginates, proteins such as gluten, zein, casein, collagen, gelatin, natural gums, cellulose (also in nanofibrils) and pectin.

[0110] The term starch is understood here to mean all types of starch, i.e. flour, native starch, hydrolyzed starch, modified starch, gelatinized starch, plasticized starch, thermoplastic starch, biological fillers comprising complexed starch or mixtures thereof. Particularly suitable for the present invention are starches, such as potato starch, corn starch, tapioca starch and pea starch. Particularly advantageous are starches that can be easily denatured and have a high initial molecular weight, such as potato or corn starch. Starch can exist as is and in chemically modified form, for example in the form of starch esters, hydroxypropyl starch and modified starches with a fatty chain having a degree of substitution of 0.2 to 2.5.

[0111] The modified starch in this application refers to the teachings contained in patents EP-0 118240 and EP-0 327 505, the starch being processed in such a way that it does not substantially show the so-called "Maltese cross" under polarized light under an optical microscope, and does not substantially show the so-called "ghost image" under phase contrast under an optical microscope. Advantageously, the modification of the starch is carried out by an extrusion process at a temperature of 110-250° C., preferably 130-180° C., at a pressure of 0.1-7 MPa, preferably 0.3-6 MPa, preferably providing a specific energy greater than 0.1 kWh / kg during said extrusion.

[0112] The modification of the starch is preferably carried out in the presence of one or more plasticizers selected from water and polyols having 2 to 22 carbon atoms in an amount of 1 to 40% w / w relative to the weight of the starch. In the case of water, this may also be the water naturally present in the starch. Among the polyols, polyols having 2 to 6 carbon atoms, their ethers, thioethers and organic and inorganic esters having 1 to 20 hydroxyl groups are preferred.

[0113] Examples of these polyols are glycerol, diglycerol, polyglycerol, pentaerythritol, ethoxylated polyglycerols, ethylene glycol, polyethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, neopentyl glycol, sorbitol, sorbitol monoacetate, sorbitol diacetate, sorbitol monoethoxylate, sorbitol diethoxylate and mixtures thereof.

[0114] In a preferred embodiment, the starch is modified in the presence of glycerol or a plasticizer mixture comprising glycerol, more preferably comprising 2-90% w / w glycerol.Preferably, the modified and cross-linked starch of the present invention comprises 1 to 40% w / w plasticizer relative to the weight of the starch.

[0115] When present, the starch is preferably in the form of particles having a circular, oval or other elliptical cross-section, the arithmetic mean diameter of which measured along the major axis of the particle is less than 1 micron, more preferably less than 0.5 μm in average diameter.

[0116] The diacid-diol polyester of the body (i) of the article of the present invention may further optionally be mixed with one or more inorganic fillers, preferably selected from kaolin, barite, clay, talc, calcium and magnesium carbonates, iron and lead carbonates, aluminum hydroxide, diatomaceous earth, aluminum sulfate, barium sulfate, silica, mica, titanium dioxide and wollastonite. Preferably, the inorganic filler content is 0 to 50% w / w, preferably 5 to 40% w / w, more preferably 10 to 30% w / w of the total composition of the body (i). In a preferred embodiment of the present invention, the inorganic filler is talc.

[0117] The diacid-diol polyester of the article of the present invention may also be optionally mixed with one or more additives selected from plasticizers, UV stabilizers, lubricants, nucleating agents, surfactants, antistatic agents, pigments, compatibilizers, lignin, silymarin organic acids, antioxidants, mildew inhibitors, waxes, and processing aids.

[0118] Each additive is preferably present in an amount less than 10 wt %, more preferably less than 5 wt %, even more preferably less than 1 wt % of the total weight of the host (i) composition.

[0119] As for the plasticizers, in addition to the plasticizers preferably used for preparing the above-mentioned modified starch, these plasticizers are selected from trimellitic acid esters, such as trimellitic acid esters with C4-C20 monohydric alcohols, the C4-C20 monohydric alcohols are preferably selected from n-octanol and n-decanol, and aliphatic esters having the following structure:

[0120] R1-OC(O)-R4-C(O)-[-O-R2-OC(O)-R5-C(O)-]mO-R3

[0121] in:

[0122] R1 is selected from one or more of H, linear and branched saturated and unsaturated C1-C24 type alkyl residues, and polyol residues esterified with C1-C24 monocarboxylic acids;

[0123] R2 comprises -CH2-C(CH3)2-CH2- and C2-C8 alkylene groups, and is composed of at least 50 mol% of said -CH2-C(CH3)2-CH2- groups;

[0124] R3 is selected from one or more of H, linear and branched saturated and unsaturated alkyl residues of polyols esterified with C1-C24 monocarboxylic acids;

[0125] R4 and R5 are the same or different and comprise one or more C2-C22, preferably C2-C11, more preferably C4-C9 olefins, and are composed of at least 50 mol% C7 olefins;

[0126] m is a number between 1-20, preferably 2-10, more preferably 3-7.

[0127] Preferably, in the ester, at least one of the radicals R1 and / or R3 comprises, in an amount of ≥10 mol %, more preferably ≥20 mol %, even more preferably ≥25 mol %, by mole, relative to the total amount of radicals R1 and / or R3, at least one polyol residue esterified with a C1-C24 monocarboxylic acid selected from stearic acid, palmitic acid, 9-keto stearic acid, 10-keto stearic acid and mixtures thereof. Examples of such aliphatic esters are disclosed in Italian patent application MI2014A000030 and in international patent applications WO2015 / 104375 and WO2015 / 104377.

[0128] Preferably, the lubricant is selected from esters and metal salts of fatty acids, such as zinc stearate, calcium stearate, aluminum stearate and acetyl stearate. Preferably, the composition of subject (i) according to the invention comprises at most 1% by weight, more preferably at most 0.5% by weight of lubricant relative to the total weight of the composition.

[0129] Examples of nucleating agents include saccharin sodium salt, calcium silicate, sodium benzoate, calcium titanate, boron nitride, isotactic polypropylene, low molecular weight PLA.

[0130] Pigments such as titanium dioxide, clays, copper phthalocyanine, titanium dioxide, silicates, iron oxides and hydroxides, carbon black and magnesium oxide may also be added if desired.

[0131] Processing aids such as slip agents and / or release agents include, for example, biodegradable fatty acid amides such as oleamide, erucamide, ethylene-bisstearamide, fatty acid esters such as oleyl or stearyl glyceride, saponified fatty acids such as stearates, inorganic agents such as silicon dioxide or talc. The processing aid 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.

[0132] Advantageously, the body (i) of the molded or thermoformed article of the invention is biodegradable according to standard EN 13432.

[0133] According to a preferred aspect, the body (i) comprises, or preferably consists of, an aliphatic-aromatic diacid-diol polyester as a main component.

[0134] According to a further preferred aspect, the host (i) comprises an aliphatic diacid-diol polyester or a mixture of an aliphatic diacid-diol polyester and a polyhydroxyalkanoate.

[0135] Other particularly preferred examples of the composition of the body (i) of the article according to the invention are:

[0136] - Composition A, relative to the total composition of body (i), comprises 20-60% w / w, preferably 25-50% w / w, of at least one aliphatic-aromatic polyester comprising 1,4-butanediol dicarboxylate units; 40-80% w / w, preferably 50-75% w / w, of at least one polyhydroxyalkanoate; optionally 0-0.5% w / w, preferably 0.01-0.25% w / w, of a crosslinker and / or chain extender, and optionally 0-10% w / w, preferably 1-5% w / w, of at least one inorganic filler.

[0137] - Composition B comprising, relative to the total composition of body (i), 30-60% w / w of at least one aliphatic polyester comprising 1,4-butanediol dicarboxylate units; 5-40% w / w of at least one polyhydroxyalkanoate; 5-40% w / w of at least one inorganic filler.

[0138] The barrier label (ii) of the biodegradable molded or thermoformed article of the present invention comprises at least one biodegradable support and at least one coating layer, wherein the biodegradable support comprises a mixture containing polyhydroxyalkanoate and at least one aliphatic and / or aliphatic-aromatic polyester. Preferably, the barrier label (ii) of the present invention is suitable for contact with food.

[0139] The biodegradable support of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention comprises a mixture comprising a polyhydroxyalkanoate constituting its continuous phase and an aliphatic and / or aliphatic-aromatic polyester constituting its discontinuous phase.

[0140] The biodegradable support preferably has an elastic modulus greater than 450 MPa.

[0141] The biodegradable support of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention comprises a mixture containing aliphatic and / or aliphatic-aromatic polyesters as discontinuous phase, the aliphatic-aromatic polyesters being preferred.

[0142] In the case of aliphatic-aromatic polyesters, this preferably includes:

[0143] (a) a dicarboxylic acid component comprising:

[0144] a1) 30 to 70 mol %, preferably 40 to 60 mol %, of units derived from at least one aromatic dicarboxylic acid;

[0145] a2) 70 to 30 mol %, preferably 60 to 40 mol %, of units derived from at least one saturated aliphatic dicarboxylic acid;

[0146] a3) 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0147] b) a diol component, comprising, relative to the total diol component:

[0148] b1) 95 to 100 mol %, preferably 97 to 100 mol %, of units derived from saturated aliphatic diols;

[0149] b2) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from at least one unsaturated aliphatic diol.

[0150] In the case of aliphatic polyesters, they preferably contain, relative to the total dicarboxylic acid components:

[0151] c) a dicarboxylic acid component comprising:

[0152] c1) 95 to 100 mol % of units derived from at least one aliphatic dicarboxylic acid;

[0153] c2) 0 to 5 mol % of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0154] d) a diol component, relative to the total diol component, comprising:

[0155] d1) 95 to 100 mol %, preferably 97 to 100 mol %, of units derived from at least one saturated aliphatic diol;

[0156] d2) 0 to 5 mol %, preferably 0 to 3 mol %, of units derived from unsaturated aliphatic diols.

[0157] Concerning components a and c of the aliphatic-aromatic and / or aliphatic polyester of the biodegradable support of the barrier label (ii), these are defined based on the description of the corresponding a and c components of the aliphatic-aromatic and / or aliphatic polyester of the body (i).

[0158] As regards the saturated aliphatic diols in components e1 and f1, these are preferably selected from 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 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-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, dianhydrosorbitol, dianhydromannitol, dianhydroiditol, cyclohexanediol, dialkylene glycols and polyalkylene glycols having a molecular weight of 100 to 4000, for example 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-ethylene glycol, 1,3-propylene glycol, 1,4-butanediol. More preferably, the diol component comprises or consists of 1,4-butanediol.

[0159] As regards the unsaturated aliphatic diols in components e2 and f2, these are 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-hexyne-1,6-diol, cis-3-hexene-1,6-diol, trans-3-hexene-1,6-diol, 3-hexyne-1,6-diol.

[0160] In a preferred embodiment, the aliphatic and / or aliphatic-aromatic polyester of the biodegradable support of the barrier label (ii) is preferably selected from the group consisting of: poly(1,4-butanediol succinate), poly(1,4-butanediol adipate), poly(1,4-butanediol azelaate), poly(1,4-butanediol sebacate), poly(1,4-butanediol tridecanoate), poly(1,4-butanediol azelaate-co-1,4-butanediol succinate), poly(1,4-butanediol adipate-co-1,4-butanediol succinate), poly(1,4-butanediol adipate-co-1,4-butanediol-2,5-furan dicarboxylate), poly(1,4-butanediol sebacate-co-1,4-butanediol-2,5-furan dicarboxylate). dicarboxylates), poly(1,4-butanediol azelaate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,4-butanediol tridecanoic acid ester-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,4-butanediol succinate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol adipate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol sebacate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol azelaate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol tridecanoic acid ester-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol tridecanoic acid ester-co-1,4-butanediol 1,4-Butanediol-2,5-furandicarboxylate), poly(1,2-ethylene glycol succinate-co-1,4-butanediol-2,5-furandicarboxylate), poly(1,4-butanediol adipate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol sebacate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol azelaate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol tridecanoate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol succinate-co-1,2-ethylene glycol-2,5-furandicarboxylate), poly(1,4-butanediol terephthalate ester), poly(1,4-butylene glycol-2,5-furan dicarboxylate), poly(1,2-ethylene glycol terephthalate-co-1,4-butylene glycol terephthalate), poly(1,3-propylene glycol terephthalate-co-1,4-butylene glycol terephthalate), poly(1,4-butylene glycol terephthalate-co-1,4-butylene glycol-2,5-furan dicarboxylate), poly(1,2-ethylene glycol terephthalate-co-1,4-butylene glycol-2,5-furan dicarboxylate), poly(1,3-propylene glycol terephthalate-co-1,4-butylene glycol-2,5-furan dicarboxylate), poly(1,2-ethylene glycol terephthalate-co-1,4-butylene glycol-2,5-furan dicarboxylate), poly(1,4-Butanediol terephthalate-co-1,2-ethylene glycol-2,5-furan dicarboxylate), poly(1,4-butanediol adipate-co-1,4-butanediol terephthalate), poly(1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelaate-co-1,4-butanediol terephthalate), poly(1,4-butanediol tridecanoate-co-1,4-butanediol terephthalate), poly(1,4-butanediol succinate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), Poly(1,4-butanediol azelate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol azelate-co-1,4-butanediol terephthalate), poly(1,4-butanediol succinate-co-1,4-butanediol sebacate-co-1,4-butanediol terephthalate), poly(1,4-butanediol adipate-co-1,4-butanediol succinate-co-1,4-butanediol terephthalate), poly(1,4-butanediol azelate-co-1,4-butanediol succinate-co-1,4-butanediol terephthalate), and block or random copolymers thereof. More preferably, the aliphatic and / or aliphatic-aromatic polyester is preferably selected from poly(1,4-butylene glycol azelate), poly(1,4-butylene glycol sebacate), poly(1,4-butylene glycol adipate-co-1,4-butylene glycol terephthalate), poly(1,4-butylene glycol azelate-co-1,4-butylene glycol terephthalate), poly(1,4-butylene glycol sebacate-co-1,4-butylene glycol terephthalate). esters), poly(1,4-butylene glycol adipate-co-1,4-butylene glycol sebacate-co-1,4-butylene glycol terephthalate), poly(1,4-butylene glycol azelaate-co-1,4-butylene glycol sebacate-co-1,4-butylene glycol terephthalate), poly(1,4-butylene glycol adipate-co-1,4-butylene glycol azelaate-co-1,4-butylene glycol terephthalate). ,

[0161] The aliphatic and / or aliphatic-aromatic polyester of the biodegradable support of the barrier label (ii) may also advantageously contain repeating 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 suitable 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 inserted into the chain as is or as prepolymers / oligomers, or they may also be pre-reacted with diacids or diols.

[0162] The aliphatic and / or aliphatic-aromatic polyester of the biodegradable support of the barrier label (ii) is characterized by the molecular weights Mn and Mw, MFR, terminal acid groups, intrinsic viscosity and biodegradability already defined for the aliphatic and / or aliphatic-aromatic polyester of the body (i).

[0163] The biodegradable support of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention comprises a mixture containing a polyhydroxyalkanoate forming its continuous phase.

[0164] According to one aspect of the invention, the support comprises a mixture which preferably comprises from 10% to 49% by weight, preferably from 20% to 45% by weight, more preferably from 30% to 45% by weight, of aliphatic and / or aliphatic-aromatic polyesters and from 90% to 51% by weight, preferably from 80% to 55% by weight, more preferably from 70% to 55% by weight, relative to the total weight of the mixture.

[0165] Preferably, the mixture consists of the aliphatic and / or aliphatic / aromatic polyester, the polyhydroxyalkanoate and optionally a crosslinker and / or a chain extender.

[0166] With regard to the polyhydroxyalkanoates constituting the mixture which forms the biodegradable support of the barrier label (ii), see the description of the polyhydroxyalkanoates of the body (i).

[0167] Besides comprising a mixture of polyhydroxyalkanoates constituting its continuous phase and aliphatic and / or aliphatic-aromatic polyesters constituting its discontinuous phase, the biodegradable support of the barrier label (ii) of the article of the invention may optionally comprise other polymers of synthetic or natural origin, whether biodegradable or not.

[0168] As regards the polymers of synthetic or natural origin, whether biodegradable or not, these are advantageously chosen from vinyl polymers, diacid-diol polyesters identical or different to those mentioned above, polyamides, polyurethanes, polyureas, polycarbonates and mixtures thereof, as already defined for body (i). In a particularly preferred form, said polymers may be mixed in an amount of up to 80% by weight with the aliphatic and / or aliphatic-aromatic polyesters of the biodegradable support of the barrier label (ii) of the article of the invention.

[0169] The mixture comprising polyhydroxyalkanoate and at least one aliphatic / aliphatic-aromatic polyester of the biodegradable support of the barrier label (ii) may optionally contain the following components, as already quantitatively disclosed for the subject (i): long bifunctional molecules; diamines, amino acids, amino alcohols; multifunctional molecules, crosslinkers and / or chain extenders.

[0170] In addition to the mixture comprising polyhydroxyalkanoate constituting its continuous phase and aliphatic and / or aliphatic-aromatic polyester constituting its discontinuous phase, the biodegradable support of the barrier label (ii) of the article of the invention may optionally comprise one or more additives selected from plasticizers, UV stabilizers, lubricants, nucleating agents, surfactants, antistatic agents, pigments, compatibilizers, lignin, silymarin organic acids, antioxidants, mildewicides, waxes, processing aids, as already defined for the body (i). Each additive is preferably present in an amount of less than 10% by weight, more preferably less than 5% by weight, even more preferably less than 1% by weight, based on the total weight of the composition of the support of the barrier label (ii).

[0171] Advantageously, the support of the barrier label (ii) of the moulded or thermoformed article according to the invention is biodegradable according to standard EN 13432.

[0172] Particularly preferred examples of compositions of the biodegradable support of the barrier label (ii) of the article of the present invention are:

[0173] - Composition C, comprising, relative to the total composition of the support of the barrier label (ii): 10-60% w / w, preferably 25-50% w / w, of at least one aliphatic-aromatic polyester; 20-90% w / w, preferably 40-75% w / w, of at least one polyhydroxyalkanoate; 0-10% w / w, preferably 1-5% w / w, of at least one crosslinker and / or chain extender.

[0174] - Composition D, comprising, relative to the total composition of the support of the barrier label (ii): 10-80% w / w of at least one aliphatic polyester; 20-90% w / w of at least one polyhydroxyalkanoate; 0%-10% w / w of at least one crosslinker and / or chain extender.

[0175] The biodegradable support of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention can be advantageously obtained by a film forming process, preferably a blown film forming or cast extrusion process. It can also be subjected to a biaxial orientation process and other treatments to improve the final properties of the packaging.

[0176] The biodegradable support of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention may also be subjected to activation treatment (eg, treatment to increase surface tension, such as plasma treatment, corona treatment or primer treatment) to increase adhesion of the coating layer and prevent delamination.

[0177] The surface properties of the support of the barrier label (ii) are such that effective adhesion to the coating layer and / or the body (i) is possible even with mild treatment or without such activation treatment.

[0178] The surface of the support has a roughness greater than that of a conventional PLA film. In particular, the mean square roughness (Sq) measured by atomic force microscopy (AFM) on an area of ​​10 μm×10 μm is advantageously greater than 10 nm, preferably greater than 15 nm, more preferably greater than 20 nm, even more preferably greater than 40 nm, and advantageously 45 nm or less, 35 nm or less, and preferably 30 nm or less. This is achieved, for example, by operating in tapping mode with a resolution of 256 points per 256 lines using a 225 micron long monolithic silicon microlever (cantilever), with a natural frequency of 190 kHz, a force constant of 48 N / m, and a tip radius of less than 10 nm.

[0179] The mean square roughness value Sq is calculated as the square root of the average of the squares of the deviations of the true profile from the mean line according to the following formula:

[0180]

[0181] where N is the total number of acquisitions in the region considered (eg, 10 μm x 10 μm), and r is the deviation of the actual profile in each acquisition from the mean line.

[0182] In contrast to the average roughness, the value of Sq is therefore also influenced by the amplitude of the peaks and valleys detected by the instrument on the measured surface, making it possible to distinguish surfaces that are undulating to a greater or lesser extent.

[0183] It is believed that the characteristic relief of the support has the effect of promoting the adhesion of the coating. When AFM analysis is performed under the above conditions, such a surface also shows a difference Sy between the maximum profile height (maximum peak) and the maximum profile concave depth (maximum valley) relative to the average line, which is generally greater than 90nm, advantageously greater than 95nm, preferably greater than 100, more preferably greater than 150nm, and even more preferably greater than 200nm. Advantageously, Sy is 300nm or less, preferably 280nm or less.

[0184] The thickness of the biodegradable barrier layer (ii) is advantageously less than 120 μm, more advantageously less than 80 μm, preferably less than 50 μm, most preferably less than or equal to 30 μm. The thickness of the layer may be measured by any suitable technique, for example by a micrometer or electron microscope.

[0185] In particular, the biodegradable support of the barrier label (ii) advantageously exhibits an MD (machine direction) elongation at break value (εb) of less than 400%, preferably less than 350%, more preferably less than 200%, even more preferably less than 150%, measured according to ASTM D882 (23°C, 50% relative humidity, Vo 50 mm / min).

[0186] Furthermore, the biodegradable support of the barrier label (ii) advantageously exhibits a modulus of elasticity (E) value higher than 450 MPa, preferably higher than 500 MPa, more preferably higher than 1000 MPa, measured according to ASTM D882 (23° C., 50% relative humidity, Vo 50 mm / min). In a particularly advantageous aspect, the biodegradable support of the barrier label (ii) has a modulus of elasticity (E) value higher than 1500 MPa and preferably higher than 1700 MPa.

[0187] Advantageously, the biodegradable support of the barrier label (ii) is biodegradable according to standard EN 13432.

[0188] The biodegradable support of the barrier label (ii) may be transparent or opaque. If the biodegradable support of the barrier label (ii) is transparent, it advantageously exhibits a haze value (measured according to ASTM D 1003) of less than 30%, more preferably less than 20%, more preferably less than 14%.

[0189] In a preferred embodiment, the biodegradable molded or thermoformed article according to the present invention comprises a main body (i), a barrier label (ii) adhered to the portion of the main body (i) in contact with food by an in-mold labeling method, and an additional layer adhered to the outer portion of the main body (i) by an in-mold labeling method, wherein the additional layer adhered to the outer portion has the above-mentioned composition for the biodegradable label support (ii).

[0190] The coating layer of the barrier label (ii) of the biodegradable molded or thermoformed article of the present invention is adjacent to the biodegradable support.

[0191] The coating layer may comprise inorganic materials (eg metal alkoxides, silicon oxides) or organic materials (eg proteins and / or polysaccharides or lipid-based polymers and biopolymers), possibly in combination to form mixtures or overlapping layers.

[0192] According to another embodiment of the present invention, the coating layer consists of one or more organic materials.

[0193] Among the organic materials, natural substances such as cellulose in various forms (e.g. nanocrystalline-NCC- or nanofibrillated-NFC-forms) and its derivatives, chitosan, chitin, pectin, gluten, casein, zein, starch in various forms and its derivatives, gelatin, whey protein, carrageenan, guar gum, xanthan gum, alginates and synthetic polymers such as polyvinyl alcohol, ethylene vinyl alcohol, polyvinyl acetate, ethylene vinyl acetate, acrylates, polyamides, polyvinyl chloride, organosilanes, polyethylene glycols can be used. Among the synthetic polymers, polyvinyl alcohol (i.e. polyvinyl alcohol), ethylene vinyl alcohol and polyvinyl alcohol-based polymers with different degrees of hydrolysis are preferred. Particularly preferred synthetic polymers are selected from polyvinyl alcohol, ethylene vinyl alcohol and copolymers thereof; even more preferred are polyvinyl alcohols with advantageous degrees of hydrolysis of 70-100%.

[0194] The coating layer may also include fillers, such as zeolites, graphene, graphene oxide or zirconium phosphate, to improve the properties of the final barrier.

[0195] According to one embodiment of the present invention, the coating layer is composed of one or more inorganic materials.

[0196] Inorganic materials include metals and their oxides and alkoxides, such as silver, copper, gold, aluminum, aluminum oxide, titanium oxide and / or aluminum-titanium oxide, silicon dioxide, Zn oxide.

[0197] According to another embodiment of the present invention, the coating layer consists of one or more organic materials and one or more inorganic materials in combination with each other.

[0198] According to this embodiment, preferably the coating layer comprises a first layer of organic, natural and / or synthetic material in contact with the biodegradable support of the barrier label (ii) and a second layer of metallic material covering the first layer. Such a layer configuration advantageously exhibits an enhanced barrier effect.

[0199] Preferably, the coating layer comprises one or more materials selected from the group consisting of metals and their oxides and alcohol salts, cellulose and its derivatives, starch and its derivatives, chitosan, synthetic polymers (e.g., polyvinyl alcohol, ethylene vinyl alcohol, polyvinyl acetate, ethylene vinyl acetate, acrylates, organosilanes, polyethylene glycols) and combinations thereof. With regard to starch, reference should be made to the above description of subject (i).

[0200] According to one aspect of the invention, the coating layer comprises a modified starch in the form of a polymer complex of hydrophilic groups inserted by hydrophobic sequences, such as the composition disclosed in patent application EP 2 758 465. The composition can be applied in the form of an aqueous dispersion; preferably, the composition comprises, relative to the total weight of the composition:

[0201] - from 30% to 80% modified starch;

[0202] - from 20% to 70% of polymers comprising hydrophilic groups intercalated by hydrophobic sequences;

[0203] - from 0% to 25% of plasticizer;

[0204] - From 0% to 20% water.

[0205] According to this aspect, the complexed form of modified starch refers to a modified starch that exhibits one or more crystalline forms in an X-ray spectrometer, which crystalline forms can be associated with one or more diffraction peaks listed below.

[0206]

[0207]

[0208] As regards polymers comprising hydrophilic groups intercalated by hydrophobic sequences, these polymers are preferably insoluble in water. This makes it possible to reduce the water permeability of the coating layer according to the invention.

[0209] As far as the polymers comprising hydrophilic groups interrupted by hydrophobic sequences are concerned, these polymers are advantageously chosen from:

[0210] a. Polyvinyl alcohol having a degree of hydrolysis of 10-100%;

[0211] b. vinyl alcohol / vinyl acetate block copolymer;

[0212] c. Polyvinyl acetate in dry form and in emulsified form in water;

[0213] d. Copolymers of ethylene with vinyl alcohol, vinyl acetate, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic anhydride, glycidyl methacrylate and mixtures thereof;

[0214] e. Aliphatic polyamide 6-6, 6-9 or 12, aliphatic polyurethane, aliphatic and aliphatic / aromatic polyesters, random or block copolymers polyurethane / polyamide, polyurethane / polyether, polyurethane / polyester, polyamide / polyester polyamide / polyether, polyester / polyether, polyurea / polyester, polyurea / polyether, polylactic acid, polyglycolic acid, polycaprolactone / urethane, wherein the molecular weight of the polycaprolactone block is 300 to 3000.

[0215] Mixtures of the polymers mentioned may also be used.

[0216] Among the polymers comprising hydrophilic groups inserted by hydrophobic sequences, preferred are copolymers of ethylene with vinyl alcohol and / or acrylic acid, polyvinyl alcohol with a degree of hydrolysis of 10 to 100%, polyvinyl acetate in dry form and in emulsified form in water, vinyl alcohol / vinyl acetate block copolymers and mixtures thereof.

[0217] Among them, polyvinyl alcohol and copolymers of ethylene, vinyl alcohol and acrylic acid are particularly preferred.

[0218] In the case of copolymers of ethylene and vinyl alcohol, these preferably contain from 20 to 50 mol % of ethylene units.

[0219] In the case of copolymers of ethylene and acrylic acid, they preferably contain 70 to 99% by weight of ethylene units.

[0220] The modified and complexed starch composition is preferably deposited in the form of an aqueous dispersion.

[0221] Due to the above-mentioned characteristics of the modified and complexed starch composition, when used in the coating layer of the present invention, it helps to improve its barrier properties, such as barrier properties to saturated and aromatic hydrocarbon compounds, and is therefore particularly suitable for packaging in the food industry.

[0222] The coating layer can be applied to the support using known techniques, such as those commonly used in the coating and printing industries. For example, the application can be carried out in a molten state; alternatively, the coating layer can be transferred to the surface to be coated in the form of a solution or dispersion in a solvent, so that the solvent then evaporates and the coating or lacquer solidifies, as in the case of coating methods such as scraping or film coating. In the latter case, organic solvents or water are generally used. Other application methods include transferring the coating material to the surface by sublimation (e.g. under vacuum conditions) or by electromagnetic processes.

[0223] Said application methods, which take the form of a solution or dispersion in a solvent, generally comprise a stage of depositing a layer of coating material on one surface of a support and a stage of drying said support.

[0224] After deposition, the method may advantageously also comprise removing some of the deposited coating composition from the support, thereby allowing the thickness of the coating layer to be adjusted (the so-called leveling).

[0225] As regards the stage of drying the support, it is advantageous to use a radiation system, preferably infrared, a convection system, preferably by hot air, or a contact system, preferably with drying cylinders, or any combination of these.

[0226] According to a preferred aspect of the present invention, the barrier label (ii) corresponds to the barrier film which is the subject of patent application WO2021 / 023763Al, with respect to which the biodegradable support of the present application corresponds to the biodegradable layer (i), and the coating of the barrier label of the present application represents the coating layer (ii).

[0227] The barrier label (ii) of the biodegradable molded or thermoformed article of the present invention is advantageously characterized by low permeability to gases. In particular, the barrier label (ii) of the biodegradable molded or thermoformed article according to the present invention is advantageously characterized by an oxygen permeability of less than 100 cc / m measured at 23° C. and 0% RH according to ASTM standard D3985. 2 × 24h, more preferably less than 50cc / m 2 × 24h, even more preferably less than 5cc / m 2 ×24h and greater than 0.1cc / m 2 ×24h.

[0228] The barrier label (ii) advantageously provides the biodegradable molded or thermoformed article of the present invention with low permeability to volatile substances. In particular, it advantageously allows the migration of THF into food to be reduced by at least two times, preferably 10 to 100 times, for example 15 to 50 times, compared to when the barrier label (ii) is not present.

[0229] The biodegradable molded or thermoformed article of the present invention is preferably characterized by having a THF permeation barrier to food that is two times greater than that of an unlabeled article.

[0230] The present invention is now described using some examples in the specific implementation mode, and these examples are intended to be illustrative rather than limiting the protection scope of the present patent application.

[0231] Example

[0232] Body (i) Composition 1: Poly(1,4-butylene adipate-co-1,4-butylene terephthalate) (PBAT) having 47 mol% of aromatic units relative to the dicarboxylic acid component, an MFR of 4.1 g / 10 min (measured according to ISO standard 1133-1 at 190° C. with a weight of 2.16 kg, with a water content of less than 400 ppm) and an acidity of 28 meq / kg.

[0233] Main body (i) Composition 2: 36.6% by weight of poly(1,4-butylene adipate-co-1,4-butylene terephthalate) ("PBAT") having 47 mol% of aromatic units relative to the dicarboxylic acid component, an MFR of 4.1 g / 10 min (measured according to ISO standard 1133-1 at 190°C, with a weight of 2.16 kg and a water content of less than 400 ppm), and an acidity of 28 meq / kg; 59.5% by weight of polylactic acid ("PLA") Ingeo 3251D; 1% of Mistron R10C talc; 1.9% of a masterbatch based on PLA Ingeo 325 1D, which includes 10% by weight of Joncryl ADR368CS; 1% by weight of oleamide of vegetable origin.

[0234] Main body (i) Composition 3: 54.9% by weight of poly(1,4-butylene glycol succinate) ("PBS") having an MFR of 8.3 g / 10 min (measured according to ISO standard 1133-1 at 190°C with a weight of 2.16 kg and a water content of less than 400 ppm) and an acidity of 51 meq / kg; 27.2% by weight of polylactic acid ("PLA") Ingeo 3251D; 17.3% of Mistron R10C talc; 0.6% by weight of oleamide of vegetable origin.

[0235] Body (i) Composition 4: Poly(1,4-butylene glycol succinate) ("PBS") having an MFR of 8.3 g / 10 min (measured according to ISO standard 1133-1 at 190°C with a weight of 2.16 kg, water content less than 400 ppm) and an acidity of 51 meq / kg.

[0236] The body (i) compositions 2 and 3 were fed into a co-rotating twin-screw extruder, model Icma San Giorgio MCM 25HT (L / D=52; diameter 25 mm) operated under the following conditions:

[0237] Entity (i)-2

[0238] Screw speed = 150 rpm;

[0239] Temperature distribution = 110-150-200-210×5-200×3-170×3 (℃);

[0240] Flow rate: 10.1 kg / h;

[0241] Vacuum degassing.

[0242] Subject (i)-3

[0243] Screw speed = 200 rpm;

[0244] Temperature distribution = 110-150-190-200×5-190×3-170×3 (℃);

[0245] Flow rate: 10.1 kg / h;

[0246] Vacuum degassing.

[0247] Barrier label (ii).

[0248] Biodegradable barrier labels Support It was prepared as follows: 35.8% w / w poly(butylene adipate-co-butylene terephthalate) (PBAT) having 47 mol% aromatic units relative to the dicarboxylic acid component, an MFR of 4.2 g / 10 min (190° C., 2.16 kg, water content less than 400 ppm), and an acidity of 42 meq / kg; 61.8% w / w Ingeo 3251D polylactic acid (“PLA”) having an MFR of 40 g / 10 min (190° C., 2.16 kg); 2.4% w / w masterbatch comprising 10% w / w Joncryl ADR4368CS (styrene-glycidyl-methyl methacrylate copolymer) and 90% w / w Ingeo 4043D polylactic acid (“PLA”) were fed to a twin screw extruder, model Icma San Giorgio MCM 25HT (L / D=52; diameter 25 mm), operated under the following conditions:

[0249] Screw speed = 200 rpm;

[0250] Temperature distribution = 110-150-200-210×5-200×3-170×3 (℃);

[0251] Flow rate: 10.1 kg / h;

[0252] Vacuum degassing.

[0253] The pellets obtained in this way have an MFR value of 11.4 g / 10 min (190° C., 2.16 kg, measured according to ISO 1133-1 "Plastics - Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastics - Part 1: Standard method"). The pellets are fed into a Ghioldi type blown film machine with a 40 mm diameter screw and an L / D of 30, operating at 64 rpm with a 120-200×3 temperature profile. The film forming head with an air gap of 0.9 mm and an L / D of 12 is set to 200° C. Film forming is carried out with a blow-up ratio of 3.2 and a draw ratio of 11.7.

[0254] Prepared as follows Paint layerA complexed starch-based coating composition was prepared by feeding 19.8 kg / h native corn starch (containing 12% water), 12.9 kg / h polyvinyl alcohol having a degree of hydrolysis between 84.2% and 86.2%, 2.8 kg / h glycerol and 4.5 kg / h water into an OMC type twin screw extruder operated under the following conditions:

[0255] Screw diameter (D) = 58 mm;

[0256] L / D=36;

[0257] Speed ​​= 140 rpm;

[0258] Temperature distribution = 145-170-200 × 4-150 × 2 ° C;

[0259] Production rate = 40 kg / h;

[0260] Vacuum degassing.

[0261] 20 g of the product were added to 80 g of deionized water and dispersed by a rotor stator disperser (Ika Ultra-Turrax T25) at 25000 rpm for 15 minutes. The suspension was cooled to room temperature.

[0262] The above suspension was sprayed with a spray gun at a concentration of 9.3 g / m 2 The coating is applied in the form of a layer onto the surface of the biodegradable support to obtain a barrier label (ii).

[0263] Examples 1-3

[0264] The attachment of the biodegradable support of the barrier label (ii) to each of the bodies (i) 1 to 3 is performed on the portion in contact with the food by the following in-mold labeling method.

[0265] The biodegradable support of the barrier label (ii), suitably cut to a size so that it covers the entire inner surface of the molded article, is placed in the mold, on the male shell, and introduced by injecting the molten body (i)-1, body (i)-2 or body (i)-3 composition due to the high pressure applied on the surface. The temperature profile used in the injection molding process with 4 heating zones (from the hopper to the injection nozzle) is 140-160-190-190°C and the holding pressure applied is 500 bar for a period of 2 seconds.

[0266] The molded articles obtained according to the above method had no delamination effect in each of the 3 examples, and the biodegradable support could not be removed from the body.

[0267] Example 4

[0268] The barrier label (ii) comprising both a support and a coating layer was attached to the body (i)-4 on the portion in contact with food by the in-mold labeling method described in Examples 1 to 3. The molded article obtained according to the above method had no delamination effect, showing strong adhesion of the barrier label (ii) to the body (i)-4.

[0269] In order to evaluate the barrier properties of barrier label (ii) to THF, a sealed bag of barrier label (ii) was prepared, the sealed bag containing particles of the material constituting body (i)-4 introduced as a THF source. The sealed bag was then placed in an aluminum bag containing a commercial blend of ground roasted coffee for a domestic espresso machine. The weight ratio between the particles of the material constituting body (i)-4 and the coffee powder used was 0.305.

[0270] Comparative Example 5

[0271] As a reference sample, an aluminum bag was prepared in which particles of the material constituting the body (i)-4 were directly dispersed into a commercial mixture of ground roasted coffee for a home espresso machine without a barrier label. The weight ratio between the particles of the material constituting the body (i)-4 and the coffee powder used was 0.305.

[0272] After conditioning the aluminum bags of Example 5 and Comparative Example 5 in an oven at T = 60°C for 10 days, the amount of THF that migrated into the coffee powder was determined to evaluate the barrier label performance of the label against THF. Aliquots of 4-6 g of the coffee powder sample were recovered from the aluminum bag for analysis, and the THF content was measured by GC-MS as described in WO2017 / 148931. The results obtained are reported in Table 1.

[0273] For example, the THF content of an aliquot of 4-6 g of a coffee powder sample recovered from an aluminum bag was measured as described in WO2017 / 148931A1.

[0274] sample THF penetration (ppm) Example 4 15,1 Comparative Example 5 99,6

[0275] Table 1

[0276] The results reported in Table 1 clearly show that when the barrier label (ii) is present (Example 4), the amount of THF migrating into the coffee powder is much lower than when no label is present (Comparative Example 5).

Claims

1. A biodegradable molded or thermoformed article for food packaging, comprising a body and a barrier label, wherein: i. the body comprises at least one biodegradable diacid-diol polyester comprising 1,4-butanediol dicarboxylate units; ii. The barrier label comprises at least one biodegradable support and at least one coating layer, the biodegradable support consisting of a mixture comprising polyhydroxyalkanoate and at least one aliphatic and / or aliphatic-aromatic polyester; The barrier label (ii) is adhered to the main body (i) in the portion in contact with the food by an in-mold labeling method.

2. The biodegradable molded or thermoformed article according to claim 1, characterized in that The THF permeation barrier to the food product measured as disclosed in the specification is two times greater than the THF permeation barrier of the unlabeled product.

3. The biodegradable molded or thermoformed article according to claim 1 or 2, wherein the body (i) comprises an aliphatic-aromatic diacid-diol polyester as a main component.

4. The biodegradable molded or thermoformed article according to claim 1 or 2, wherein the body (i) comprises, relative to the total composition of the body (i), 20-60% w / w of at least one aliphatic-aromatic polyester comprising 1,4-butanediol dicarboxylate units; 40-80% w / w of at least one polyhydroxyalkanoate; optionally 0-0.5% w / w of a crosslinker and / or a chain extender.

5. The biodegradable molded or thermoformed article according to claim 1 or 2, wherein the body (i) comprises, relative to the total composition of the body (i), 30-60% w / w of at least one aliphatic polyester comprising 1,4-butanediol dicarboxylate units; 5-40% w / w of at least one polyhydroxyalkanoate; 5-40% w / w of at least one inorganic filler.

6. The biodegradable molded or thermoformed article according to any one of claims 1 to 5, wherein the support of the barrier label (ii) comprises, relative to the total composition of the support of the barrier label (ii): 10-60% w / w of at least one aliphatic-aromatic polyester; 20-90% w / w of at least one polyhydroxyalkanoate; 0-10% w / w of at least one crosslinker and / or chain extender.

7. The biodegradable molded or thermoformed article according to any one of claims 1 to 6, wherein the polyhydroxyalkanoate of the support of the barrier label (ii) is a lactic acid polyester.

8. The biodegradable molded or thermoformed article according to any one of claims 1 to 7, wherein the coating layer comprises inorganic or organic materials, which may be combined with each other to form a mixture or overlapping layers.

9. The biodegradable molded or thermoformed article according to any one of claims 1 to 8, which is biodegradable in industrial composting according to standard EN 13432.

10. The biodegradable molded or thermoformed article according to any one of claims 1 to 9, which is obtained by injection molding.

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