Highly degradable multilayer biodegradable film

Abstract

Multilayer biodegradable film, in particular suitable for the manufacture of packaging, comprising at least one layer (A) comprising at least one aliphatic-aromatic biodegradable polyester blended with an aliphatic polyester having at least 70 mol% of succinic acid and at least one layer (B) comprising a polymer composition comprising an aliphatic-aromatic polymer. The film has high mechanical properties, in particular high elastic modulus, and appreciable optical transparency properties.

Description

[0001] This invention relates to a multilayer biodegradable film, which is particularly suitable for manufacturing various types of packaging, especially bags for transporting goods and bags for food packaging, such as bags for fruits and vegetables. In addition to high mechanical properties, particularly a high modulus of elasticity, this film also possesses considerable optical transparency.

[0002] The manufacture of packaging, particularly bags for food packaging such as fruit and vegetable bags, requires the use of films that combine good mechanical properties with other consumer-friendly properties, such as optical transparency, which allows consumers to utilize the packaging by recognizing the contents from the outside.

[0003] In the field of biodegradable packaging, in addition to mechanical and optical issues, there is a need for materials that can degrade once they have reached the end of their primary use without creating waste accumulation in the environment.

[0004] Developing biodegradable films that combine these different properties is indeed a challenge, requiring a balance of diverse and often highly inconsistent requirements. Indeed, while specific standards for mechanical properties and biodegradability can be achieved by using material compositions that account for the individual properties of the final film according to their respective performance characteristics, achieving high optical transparency is often significantly hampered by the heterogeneity of the composition. For manufacturers of films used in biodegradable packaging, this means they must decide whether to use films with high mechanical and biodegradability properties along with suboptimal optical transparency, or vice versa, or to utilize aspects related to the optical properties of the packaging, thus accepting lower performance in terms of mechanical and biodegradability properties.

[0005] The applicant has discovered compositions that achieve an excellent balance between optical properties, mechanical properties, and high biodegradability. Two patent applications, WO2017216150 and WO2017216158, should be considered in this regard.

[0006] Specifically, WO2017216150 describes a multilayer film comprising at least a first layer A and at least a second layer B, wherein layer A and layer B are different from each other, wherein layer A comprises at least one aliphatic biodegradable polyester and at least one aliphatic-aromatic polyester, and wherein layer B comprises primarily aromatic aliphatic polyester, natural polymers such as starch and polyhydroxyalkanoates.

[0007] Although the multilayer membranes described in WO2017216150 have very good mechanical and optical properties and are biodegradable under industrial and domestic composting conditions according to UNI 11355, further formulation improvements have been made to enable the multilayer membranes to decompose more rapidly.

[0008] Home composting involves sorting household and garden organic waste and converting it into compost using a composter with ventilation holes and a removable cover, located in the garden, vegetable patch, or land. Decomposition rate is known to be a particularly important property of biodegradable polymers because it ensures a shorter composting cycle, thus increasing compost productivity. This aspect is particularly preferred under home composting conditions (T=28°C), where decomposition kinetics are slower compared to industrial composting (conducted at T=58°C).

[0009] Therefore, the object of the present invention is a multilayer film comprising at least a first layer A and at least a second layer B, wherein layer A comprises:

[0010] (i) 97% to 60% by weight of at least one aliphatic / aromatic polyester relative to the sum of components i to v, said aliphatic / aromatic polyester comprising:

[0011] (a) A dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0012] (a1) 30 mol% to 70 mol%, preferably 40 mol% to 60 mol% of units derived from at least one aromatic dicarboxylic acid;

[0013] (a2) 70 mol% to 30 mol%, preferably 60 mol% to 40 mol% of units derived from at least one saturated aliphatic dicarboxylic acid;

[0014] (a3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0015] (b) A diol component, relative to the total diol component, comprising:

[0016] (b1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0017] (b2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0018] (ii) 3% to 40% by weight of at least one aliphatic polyester relative to the sum of components i to v, said aliphatic polyester comprising:

[0019] (c) A dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0020] (c1) 70 mol% to 97 mol% of units derived from succinic acid;

[0021] (c2) 3 mol% to 30 mol% of units derived from at least one saturated dicarboxylic acid other than succinic acid;

[0022] (d) A diol component, relative to the total diol component, comprising:

[0023] (d1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0024] (d2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0025] (iii) at least one polyhydroxyalkanoate, from 0% to 37% by weight relative to the sum of components i to v;

[0026] (iv) 0% to 10% by weight of at least one inorganic filler relative to the sum of components i to v;

[0027] (v) 0% to 5% by weight of at least one crosslinking agent and / or chain extender relative to the sum of components i to v, said crosslinking agent and / or chain extender comprising at least one difunctional and / or polyfunctional compound having a group selected from: isocyanate, peroxide, carbodiimide, isocyanurate, Azoline, epoxide, acid anhydride, divinyl ether and mixtures thereof;

[0028] The condition is that, relative to components i to v, if component iii is equal to 0, then component iv must be greater than 0, preferably 0.1 to 8%, even more preferably 3 to 5%, and component (i) must be included in 96.9% to 60%;

[0029] And layer B contains:

[0030] (vi) 99.9% to 50% by weight of at least one aliphatic-aromatic polyester relative to the sum of components vi. to x., said aliphatic-aromatic polyester comprising:

[0031] (e) a dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0032] (e1) 30 mol% to 70 mol% of units derived from at least one aromatic dicarboxylic acid;

[0033] (e2) 70 mol% to 30 mol% of units derived from at least one saturated aliphatic dicarboxylic acid;

[0034] (e3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0035] (f) A diol component, relative to the total diol component, comprising:

[0036] (f1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0037] (f2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0038] (vii) 0.1% to 50% by weight of at least one polymer of a natural source relative to the sum of components vi. to x.;

[0039] (viii) At least one polyhydroxyalkanoate, from 0% to 40% by weight, relative to the sum of components vi. to x.;

[0040] (ix) At least one inorganic filler, from 0% to 15% by weight, relative to the sum of components vi. to x.

[0041] (x) 0% to 5% by weight of at least one crosslinking agent and / or chain extender relative to the sum of components vi. to x., said crosslinking agent and / or chain extender comprising at least one difunctional and / or polyfunctional compound having a group selected from: isocyanate, peroxide, carbodiimide, isocyanurate, Azoline, epoxide, acid anhydride, divinyl ether and mixtures thereof.

[0042] A particular feature of the multilayer film according to the invention is that its layered structure comprises at least one layer (layer A) and at least one layer (layer B), said layer A comprising at least one biodegradable aliphatic-aromatic polyester (component i) blended with an aliphatic polyester (component ii, 3 wt% to 40 wt%, relative to the sum of components i. to v. in layer A), said aliphatic polyester having at least 70 mol% succinic acid, said layer B comprising a polymer composition comprising an aliphatic-aromatic polymer optionally blended with a polyhydroxyalkanoate portion (component viii, 0 wt% to 40 wt%, relative to the sum of components in layer B) and a natural polymer (component vii, 0.1 wt% to 50 wt%, relative to the sum of components in layer B).

[0043] Surprisingly, multilayer films with this material combination have been found to possess excellent mechanical properties, biodegradability, and optical properties, making them suitable for manufacturing various types of packaging. Most importantly, the combination of layers A and B according to the invention enables the film to decompose extremely rapidly under industrial composting conditions, and more preferably in home composting, according to UNI 11355. The film also exhibits a high level of mechanical properties and is extremely thin; for example, if in the form of a bag with a height not exceeding 50 cm, a width not exceeding 40 cm (with or without gussets), and in the case of a bag with handles, a width of 6.5 to 4 cm, and a thickness of less than 15 μm, and more preferably less than 13 μm, the bag can support a weight of at least 3 kg, and even more preferably at least 4 kg, under dynamic testing conditions.

[0044] For example, dynamic testing could include placing the bag and lifting it 40 cm above the ground 10 times consecutively without any tearing. The multilayer film according to the invention has optical properties similar to those of the multilayer film in the aforementioned patent application WO2017216150, while also increasing the biodegradability of the multilayer film. Specifically, referring to films with a thickness of less than 13 μm, the multilayer film has a light transmittance of greater than 90%, preferably greater than 91%; a haze (turbidity) of less than 65%, preferably less than 45%; and a clarity (sharpness) of greater than 20%, preferably greater than 40%, and even more preferably greater than 55% (measured according to ASTM D1003).

[0045] The present invention also relates to various types of packaging including the multilayer film, particularly bags for transporting goods and bags for food packaging, such as bags for food and vegetables. The multilayer film is also particularly suitable for the field of cover sheets.

[0046] The multilayer film according to the invention comprises at least one layer A and at least one layer B, preferably characterized by an arrangement of A / B and A / B / A.

[0047] Layer A

[0048] As for layer A, it comprises at least one aliphatic polyester and at least one aliphatic-aromatic polyester, which includes:

[0049] i) 97% to 60% by weight of at least one aliphatic / aromatic polyester relative to the sum of components i to v, said aliphatic / aromatic polyester comprising:

[0050] (a) A dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0051] (a1) 30 mol% to 70 mol%, preferably 40 mol% to 60 mol% of units derived from at least one aromatic dicarboxylic acid;

[0052] (a2) 70 mol% to 30 mol%, preferably 60 mol% to 40 mol% of units derived from at least one saturated aliphatic dicarboxylic acid;

[0053] (a3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0054] (b) A diol component, relative to the total diol component, comprising:

[0055] (b1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0056] (b2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0057] ii) 3% to 40% by weight of at least one aliphatic polyester relative to the sum of components i to v, said aliphatic polyester comprising:

[0058] (c) A dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0059] (c1) 70 mol% to 97 mol% of units derived from succinic acid;

[0060] (c2) 3 mol% to 30 mol% of units derived from at least one saturated dicarboxylic acid other than succinic acid;

[0061] (d) A diol component, relative to the total diol component, comprising:

[0062] (d1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0063] (d2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0064] (iii) at least one polyhydroxyalkanoate, from 0% to 37% by weight relative to the sum of components i to v;

[0065] (iv) 0% to 10% by weight of at least one inorganic filler relative to the sum of components i to v;

[0066] (v) 0% to 5% by weight of at least one crosslinking agent and / or chain extender relative to the sum of components i to v, said crosslinking agent and / or chain extender comprising at least one difunctional and / or polyfunctional compound having a group selected from: isocyanate, peroxide, carbodiimide, isocyanurate, Azoline, epoxide, acid anhydride, divinyl ether and mixtures thereof;

[0067] The condition is that, relative to components i to v, if component iii is equal to 0, then component iv must be greater than 0, preferably 0.1 to 8%, even more preferably 3 to 5%, and component (i) must be included in 96.9% to 60%.

[0068] As for component i. in layer A, relative to the sum of components i. to v., it contains 97% to 60% by weight, preferably 96.9% to 60%, more preferably 96% to 70% by weight, and even more preferably 96% to 88% by weight of aliphatic-aromatic polyester.

[0069] The aromatic dicarboxylic acid in component a1 is preferably selected from phthalic acid-type aromatic dicarboxylic acids, preferably terephthalic acid or isophthalic acid, more preferably terephthalic acid; and heterocyclic dicarboxylic acid aromatic 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.

[0070] In a preferred embodiment, the aromatic dicarboxylic acid comprises: 1% to 99%, preferably 5% to 95%, and more preferably 10% to 80% of terephthalic acid, its ester or salt, on a molar basis; and 99% to 1%, preferably 95% to 5%, and more preferably 90% to 20% of 2,5-furandicarboxylic acid, its ester or salt, on a molar basis.

[0071] Preferably, the saturated aliphatic dicarboxylic acid in component a2 is selected from saturated C2-C24 dicarboxylic acids, preferably C4-C13 dicarboxylic acids, more preferably C4-C11 dicarboxylic acids; their C1-C24 alkyl esters, 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, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, octadecanoic acid and their C1-24 alkyl esters. In a preferred embodiment of the invention, the saturated aliphatic dicarboxylic acid comprises a mixture containing at least 50 mol%, preferably more than 60 mol%, more preferably more than 65 mol% of the following components: succinic acid, adipic acid, azelaic acid, sebacic acid, tridecanoic acid; their C1-C24 esters, preferably C1-C4 esters; and mixtures thereof. In a particularly preferred embodiment, the mixture comprises or consists of adipic acid and azelaic acid, and contains azelaic acid in an amount of 5 mol% to 40 mol%, more preferably 10 mol% to 35 mol%, relative to the total amount of adipic acid and azelaic acid.

[0072] The unsaturated aliphatic dicarboxylic acid in component a3 is preferably selected from itaconic acid, fumaric acid, 4-methylene pimelic acid, 3,4-bis(methylene)azelaic acid, 5-methyleneazelaic acid; their C1-C24 alkyl esters, preferably C1-C4 alkyl esters; their salts and mixtures thereof. In a preferred embodiment of the invention, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid comprising at least 50 mol%, preferably greater than 60 mol%, more preferably greater than 65 mol%; and mixtures thereof with their C1-C24 esters, preferably C1-C4 esters. More preferably, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid.

[0073] As for the saturated aliphatic diols in component b1, these are preferably selected from 1,2-ethylene glycol, 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-tetratediol, 1,4-cyclohexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, disohydrated sorbitol, disohydrated mannitol, disohydrated idutol, cyclohexanediol, cyclohexanemethyldiol, dialkylene glycols, and polyalkylene glycols with a molecular weight of 100 to 4000, 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-ethylene glycol, 1,3-propanediol, and 1,4-butanediol. More preferably, the diol component comprises or is composed of 1,4-butanediol.

[0074] As for the unsaturated aliphatic diols in component b2, these are preferably selected from cis-2-buten-1,4-diol, trans-2-buten-1,4-diol, 2-butyn-1,4-diol, cis-2-penten-1,5-diol, trans-2-penten-1,5-diol, 2-pentyn-1,5-diol, cis-2-hexen-1,6-diol, trans-2-hexen-1,6-diol, 2-hexyn-1,6-diol, cis-3-hexen-1,6-diol, trans-3-hexen-1,6-diol, and 3-hexyn-1,6-diol.

[0075] The molecular weight Mn of the aliphatic-aromatic polyester described in layer A is preferably greater than 20,000, more preferably greater than 40,000. As for the molecular weight polydispersity index Mw / Mn, it is preferably 1.5 to 10, more preferably 1.6 to 5, and even more preferably 1.8 to 2.7.

[0076] Molecular weights Mn and Mw can be measured by gel permeation chromatography (GPC). The determination can be performed as follows: a chromatographic system maintained at 40°C is used with two columns in series (5 μm and 3 μm particle sizes, with mixed porosities), a refractive index detector, chloroform as eluent (flow rate 0.5 ml / min), and polystyrene as a reference standard.

[0077] Preferably, the aliphatic-aromatic polyester in layer A has an intrinsic viscosity greater than 0.3 dl / g, more preferably from 0.3 dl / g to 2 dl / g, and more preferably from 0.4 dl / g to 1.2 dl / g (measured using a Ubbelohde viscometer at 25°C for a solution of CHCl3 with a concentration of 0.2 g / dl).

[0078] The terminal acid group content of the aliphatic-aromatic polyester in layer A is preferably less than 100 meq / kg, more preferably less than 60 meq / kg, and even more preferably less than 40 meq / kg.

[0079] The content of terminal acid groups can be measured as is known in the art, for example, as disclosed in WO2017216150.

[0080] The aliphatic-aromatic polyester in layer A is biodegradable. In the context of this invention, a biodegradable polymer means a polymer that is biodegradable according to EN 13432.

[0081] The aliphatic-aromatic polyester in layer A can be synthesized according to any method known in the art. In particular, it can be advantageously obtained using a polycondensation reaction.

[0082] Advantageously, the synthesis process can be carried out in the presence of a suitable catalyst. Suitable catalysts include, for example, organometallic tin compounds, such as stannate derivatives; titanium compounds, such as n-butyl titanate; aluminum compounds, such as triisopropylaluminum; antimony and zinc compounds; and zirconium compounds and mixtures thereof.

[0083] Regarding component ii. in layer A, relative to the sum of components i. to v., it comprises 3% to 30% by weight, preferably 4% to 25% by weight, even more preferably 4% to 12% by weight, of an aliphatic polyester comprising a dicarboxylic acid component, which, relative to the total amount of the dicarboxylic acid component, comprises 70% to 97% by molar, preferably 70% to 90%, even more preferably 72% to 82% by molar units derived from succinic acid (component c1) and 3% to 30% by molar, preferably 10% to 30% by molar units derived from at least one saturated dicarboxylic acid other than succinic acid (component c2).

[0084] The saturated aliphatic dicarboxylic acids in component c2, excluding succinic acid, are preferably selected from C5-C24 saturated dicarboxylic acids, more preferably C5-C13 saturated dicarboxylic acids, and even more preferably C7-C11 saturated dicarboxylic acids; their C1-C24 alkyl esters, preferably C1-C4 alkyl esters; their salts and mixtures. Preferably, the saturated aliphatic dicarboxylic acids are selected from: succinic acid (component c1), 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, and their C1-24 alkyl esters. In a particularly preferred aspect of the invention, component c2 is azelaic acid.

[0085] As for the diol component d, it contains saturated aliphatic component d1 and unsaturated aliphatic component d2.

[0086] As for the saturated aliphatic diols in component d1, these are preferably selected from 1,2-ethylene glycol, 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-tetratediol, 1,4-cyclohexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, disohydrated sorbitol, disohydrated mannitol, disohydrated idutol, cyclohexanediol, cyclohexanemethyldiol, dialkylene glycols, and polyalkylene glycols with a molecular weight of 100 to 4000, 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-ethylene glycol, 1,3-propanediol, and 1,4-butanediol. More preferably, the diol component comprises or is composed of 1,4-butanediol.

[0087] As for the unsaturated aliphatic diols in component d2, these are preferably selected from cis-2-buten-1,4-diol, trans-2-buten-1,4-diol, 2-butyn-1,4-diol, cis-2-penten-1,5-diol, trans-2-penten-1,5-diol, 2-pentyn-1,5-diol, cis-2-hexen-1,6-diol, trans-hexen-1,6-diol, 2-hexyn-1,6-diol, cis-3-hexen-1,6-diol, trans-3-hexen-1,6-diol, and 3-hexyn-1,6-diol.

[0088] The molecular weight Mn of the aliphatic polyester ii. in layer A is preferably greater than 20,000, more preferably greater than 40,000. As for the molecular weight polydispersity index Mw / Mn, it is preferably 1.5 to 10, more preferably 1.6 to 5, and even more preferably 1.8 to 2.7.

[0089] Molecular weights Mn and Mw can be measured by gel permeation chromatography (GPC). The determination can be performed as follows: a chromatographic system maintained at 40°C is used with two columns in series (particle sizes of 5 μm and 3 μm, with mixed porosities), a refractive index detector, chloroform as eluent (flow rate 0.5 ml / min), and polystyrene as a reference standard.

[0090] Preferably, the aliphatic polyester ii. has an intrinsic viscosity greater than 0.3 dl / g, preferably from 0.3 dl / g to 2 dl / g, more preferably from 0.4 dl / g to 1.4 dl / g (measured using an Ubbelohde viscometer at 25°C for a solution of CHCl3 with a concentration of 0.2 g / dl).

[0091] The terminal acid group content of the aliphatic polyester ii. is preferably from 30 meq / kg to 160 meq / kg.

[0092] The content of terminal acid groups can be measured as is known in the art, for example, as disclosed in WO2017216150.

[0093] The aliphatic polyester ii. can be synthesized according to any method known in the art. In particular, it can be advantageously obtained by polycondensation reaction.

[0094] Advantageously, the synthesis process can be carried out in the presence of a suitable catalyst. Suitable catalysts include, for example, organometallic tin compounds, such as stannic acid derivatives; titanium compounds, such as n-butyl titanate; aluminum compounds, such as triisopropylaluminum; antimony and zinc compounds, as well as zirconium compounds; and mixtures thereof.

[0095] The aliphatic polyester (component ii.) in layer A is biodegradable. In the context of this invention, a biodegradable polymer means a polymer that is biodegradable according to EN 13432.

[0096] Regarding component iii. of layer A, relative to the sum of components i. to v., it optionally contains at least one polyhydroxyalkanoate, preferably 0 to 37%, more preferably 5 to 37%, and even more preferably 10 to 25%.

[0097] The polyhydroxyalkanoate is more preferably selected from polyesters of lactic acid, poly-ε-caprolactone, polyhydroxybutyrate, polyhydroxybutyrate-valerate, polyhydroxybutyrate-propionate, polyhydroxybutyrate-hexanoate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-dodecanoate, polyhydroxybutyrate-hexadecanoate, polyhydroxybutyrate-octadecanoate, and poly-3-hydroxybutyrate-4-hydroxybutyrate. Preferably, the polyhydroxyalkanoate comprises at least 80% by weight of a polyester of one or more lactic acids.

[0098] In a preferred embodiment, the lactic acid polyester is selected from poly-L-lactic acid, poly-D-lactic acid, poly-DL-lactic acid stereocomplexes, copolymers comprising more than 50 mol% of said lactic acid polyester, or mixtures thereof. Particularly preferred are lactic acid polyesters comprising at least 95 wt% of repeating units derived from L-lactic acid or D-lactic acid or mixtures thereof, having a molecular weight Mw greater than 50,000 and a shear viscosity (measured according to ASTM standard D3835 at T = 190°C, shear rate = 1000 / s, D = 1 mm, L / D = 10).

[0099] In a particularly preferred embodiment of the invention, the lactic acid polyester comprises at least 95% by weight of units derived from L-lactic acid and <5% of repeating units derived from D-lactic acid, having a melting point in the range of 135°C to 180°C, a glass transition temperature (Tg) in the range of 55°C to 65°C, and an MFR in the range of 1 g / 10 min to 50 g / 10 min (measured according to ISO 1133-1 at 190°C and 2.16 kg). Commercial examples of lactic acid polyesters having these properties include, for example, Ingeo. TM 4043D, 3250D and 6202D biopolymer products.

[0100] In the composition of layer A, relative to the sum of components i to v, there is at least one inorganic filler (component iv) by weight, which is 0% to 10%, preferably 0.1% to 8%, even more preferably 3% to 5%, 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.

[0101] In a preferred embodiment of the invention, the inorganic filler in the composition of layer A comprises talc, mica, calcium carbonate, or mixtures thereof, which are present in the form of particles with an average arithmetic diameter of less than 10 micrometers, more preferably less than 2 micrometers, measured relative to the long axis of the particles (measured according to ASTM 13320). Indeed, fillers of the above types that do not feature the aforementioned average arithmetic diameter have been found to exhibit significantly lower decomposition characteristics during industrial composting of objects containing them.

[0102] If component iii. is equal to 0, then component iv. must be greater than 0, preferably 0.1 to 8%, even more preferably 3 to 5%, relative to components i. to v.

[0103] The composition of layer A also contains, relative to the sum of components i to v, at least one crosslinking agent and / or chain extender, at 0% to 5% by weight, preferably 0% to 0.5% by weight, to improve hydrolytic stability (component v).

[0104] The crosslinking agent and / or chain extender are selected from difunctional and / or polyfunctional compounds having groups selected from the following: isocyanates, peroxides, carbodiimides, isocyanurates, Azoline, epoxide, acid anhydride or divinyl ether or a mixture thereof.

[0105] Particularly preferred are mixtures of difunctional and / or polyfunctional compounds with isocyanate groups and difunctional and / or polyfunctional compounds with epoxy groups, and even more preferred are mixtures comprising at least 75% by weight of difunctional and / or polyfunctional compounds with isocyanate groups.

[0106] Compounds having two polyfunctional groups including an isocyanate group are preferably selected from p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene-4-chloro diisocyanate, 1,5-naphthalene diisocyanate, 4,4-diphenylene diisocyanate, 3,3'-dimethyl-4,4-diphenylmethane diisocyanate, 3-methyl-4,4'-diphenylmethane diisocyanate, diphenyl ester diisocyanate, 2,4-cyclohexane diisocyanate, 2,3-cyclohexane diisocyanate, 1 1-Methyl-2,4-cyclohexyl diisocyanate, 1-methyl-2,6-cyclohexyl diisocyanate, bis-(isocyanatecyclohexyl)methane, 2,4,6-toluene triisocyanate, 2,4,4-diphenyl ether triisocyanate, polymethylene-polyphenyl-polyisocyanate, methylene diphenyl diisocyanate, triphenylmethane triisocyanate, 3,3'-dimethyltoluene-4,4-diisocyanate, 4,4'-methylene-bis(2-methylphenyl isocyanate), hexamethylene-1,3-cyclohexyl diisocyanate, 1,2-cyclohexyl diisocyanate, and mixtures thereof. In a preferred embodiment, the compound containing the isocyanate group is 4,4-diphenylmethane diisocyanate.

[0107] As for difunctional and polyfunctional compounds with peroxide groups, 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, dihexadecylperoxydicarbonate, ditetradecylperoxydicarbonate, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, di(2-ethylhexyl)peroxydicarbonate, and mixtures thereof.

[0108] Preferably, the difunctional and polyfunctional compounds with carbodiimide groups used in the compositions according to the invention are selected from poly(cyclooctylcarbodiimide), poly(1,4-dimethylenecyclohexylcarbodiimide), poly(cyclohexylcarbodiimide), poly(ethylcarbodiimide), poly(butylcarbodiimide), poly(isobutylcarbodiimide), poly(nonylcarbodiimide), poly(dodecylcarbodiimide), poly(neopentylcarbodiimide), poly(1,4-dimethylenephenylcarbodiimide), and poly(2,2',6,6'-tetraisopropyldiphenylcarbodiimide). Poly(2,4,6-triisopropyl-1,3-phenylenecarbodiimide) Poly(2,6-diisopropyl-1,3-phenylenecarbodiimide) Poly(tolylcarbodiimide) Poly(tolylcarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-biphenylcarbodiimide), poly(p-phenylcarbodiimide), poly(m-phenylcarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylcarbodiimide), poly(isophoronecarbodiimide), poly(cumenecarbodiimide), p-phenylbis(ethylcarbodiimide), 1,6-hexamethylenebis(ethylcarbodiimide), 1,8-octamethylenebis(ethylcarbodiimide), 1,10-decamethylenebis(ethylcarbodiimide), 1,12-dodecamethylenebis(ethylcarbodiimide), and mixtures thereof.

[0109] Examples of difunctional and polyfunctional compounds with epoxy groups that can be advantageously used in the compositions according to the invention are all polyepoxides derived from epoxidized oils and / or from styrene-glycidyl ether-methyl methacrylate or glycidyl ether-methyl methacrylate, having a molecular weight in the range of 1,000 to 10,000 and an epoxy number per molecule of 1 to 30, preferably 5 to 25, wherein the epoxide is selected from the group consisting of: diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, 2-epoxybutane, polyglycerol polyglycidyl ether, isoprene diepoxide and alicyclic diepoxide, 1,4-cyclohexanediethanol diglycidyl ether, glycidyl-2-methylphenyl ether, propoxylated triglycidyl ether, propoxylated triglycidyl ether, tetraglycidyl ether of m-xylenediamine and diglycidyl ether of bisphenol A, and mixtures thereof.

[0110] Together with those containing isocyanate groups, peroxide groups, carbodiimide groups, isocyanurate groups, etc., as mentioned above Difunctional and polyfunctional compounds with zoline, epoxy, anhydride, and divinyl ether groups can also be used with catalysts to increase the reactivity of the reactive groups. In the case of polyepoxides, fatty acid salts can be used, and even more preferably calcium stearate and zinc stearate.

[0111] In a particularly preferred embodiment of the invention, the crosslinking agent and / or chain extender comprises a compound with an isocyanate group, preferably 4,4-diphenylmethane diisocyanate; and / or a compound with a carbodiimide group; and / or a compound with an epoxy group, preferably styrene-glycidyl ether methyl methacrylate type.

[0112] Layer B

[0113] As for layer B, it includes:

[0114] (vi) 99.9% to 50% by weight of at least one aliphatic-aromatic polyester relative to the sum of components vi. to x., said at least one aliphatic-aromatic polyester comprising:

[0115] (e) a dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0116] (e1) 30 mol% to 70 mol% of units derived from at least one aromatic dicarboxylic acid;

[0117] (e2) 70 mol% to 30 mol% of units derived from at least one saturated aliphatic dicarboxylic acid;

[0118] (e3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0119] (f) A diol component, relative to the total diol component, comprising:

[0120] (f1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0121] (f2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol;

[0122] (vii) 0.1% to 50% by weight of at least one polymer of a natural source relative to the sum of components vi. to x.;

[0123] (viii) At least one polyhydroxyalkanoate, from 0% to 40% by weight, relative to the sum of components vi. to x.;

[0124] (ix) At least one inorganic filler, from 0% to 15% by weight, relative to the sum of components vi. to x.

[0125] (x) 0% to 5% by weight of at least one crosslinking agent and / or chain extender relative to the sum of components vi. to x., said at least one crosslinking agent and / or chain extender comprising at least one difunctional and / or polyfunctional compound having the following: isocyanate group, peroxide group, carbodiimide group, isocyanurate group, Azoline, epoxy, acid anhydride or divinyl ether and mixtures thereof.

[0126] As for component vi. of layer B, relative to the sum of components vi. to x., component vi. comprises 99.9% to 50% by weight, preferably 95% to 65% by weight, of aliphatic-aromatic polyester.

[0127] The aromatic dicarboxylic acid in component e1 is preferably selected from phthalic acid-type aromatic dicarboxylic acids, 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.

[0128] In a preferred embodiment, the aromatic dicarboxylic acid comprises: 1% to 99%, preferably 5% to 95%, and more preferably 10% to 80% of terephthalic acid, its ester or salt, on a molar basis; and 99% to 1%, preferably 95% to 5%, and more preferably 90% to 20% of 2,5-furandicarboxylic acid, its ester or salt, on a molar basis.

[0129] Preferably, the saturated aliphatic dicarboxylic acid in component e2 is selected from saturated C2-C24 dicarboxylic acids, preferably C4-C13 dicarboxylic acids, more preferably C4-C11 dicarboxylic acids; their C1-C24 alkyl esters, 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, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, octadecanoic acid, and their C1-24 alkyl esters. In a preferred embodiment of the invention, the saturated aliphatic dicarboxylic acid comprises a mixture containing at least 50 mol%, preferably greater than 60 mol%, more preferably greater than 65 mol% of succinic acid, adipic acid, azelaic acid, sebacic acid, tridecanoic acid; their C1-C24 esters, preferably C1-C4 esters; and mixtures thereof. In a particularly preferred embodiment, the mixture comprises or consists of adipic acid and azelaic acid, and the mixture contains azelaic acid in an amount of 5 mol% to 70 mol%, more preferably 10 mol% to 55 mol%, and even more preferably 12 mol% to 45 mol% of azelaic acid relative to the sum of adipic acid and azelaic acid.

[0130] The unsaturated aliphatic dicarboxylic acid in component e3 is preferably selected from itaconic acid, fumaric acid, 4-methylene pimelic acid, 3,4-bis(methylene)azelaic acid, 5-methyleneazelaic acid; their C1-C24 alkyl esters, preferably C1-C4 alkyl esters; their salts and mixtures thereof. In a preferred embodiment of the invention, the unsaturated aliphatic dicarboxylic acid comprises a mixture of itaconic acid and its C1-C24 esters, preferably C1-C4 esters, containing at least 50 mol%, preferably more than 60 mol%, more preferably more than 65 mol%. More preferably, the unsaturated aliphatic dicarboxylic acid comprises itaconic acid.

[0131] As for the saturated aliphatic diols in component f1, these are preferably selected from 1,2-ethylene glycol; 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-cyclohexanediol; neopentanediol; 2-methyl-1,3-propanediol; disohydrated sorbitol; disohydrated mannitol; disohydrated idutol; cyclohexanediol; cyclohexanemethyldiol; dialkylene glycols; and polyalkylene glycols with a molecular weight of 100 to 4000, 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-ethylene glycol, 1,3-propanediol, and 1,4-butanediol. More preferably, the diol component comprises or is composed of 1,4-butanediol.

[0132] As for the unsaturated aliphatic diols in component f2, these are preferably selected from cis-2-buten-1,4-diol, trans-2-buten-1,4-diol, 2-butyn-1,4-diol, cis-2-penten-1,5-diol, trans-2-penten-1,5-diol, 2-pentyn-1,5-diol, cis-2-hexen-1,6-diol, trans-2-hexen-1,6-diol, 2-hexyn-1,6-diol, cis-3-hexen-1,6-diol, trans-3-hexen-1,6-diol, and 3-hexyn-1,6-diol.

[0133] The aliphatic-aromatic polyester in layer B preferably has a molecular weight Mn greater than 20,000, more preferably greater than 40,000. As for the molecular weight polydispersity index Mw / Mn, it is preferably 1.5 to 10, more preferably 1.6 to 5, and even more preferably 1.8 to 2.7.

[0134] Molecular weights Mn and Mw can be measured by gel permeation chromatography (GPC). The determination can be performed as follows: a chromatographic system maintained at 40°C is used with two columns in series (5 μm and 3 μm particle sizes, with mixed porosities), a refractive index detector, chloroform as eluent (flow rate 0.5 ml / min), and polystyrene as a reference standard.

[0135] Preferably, the intrinsic viscosity of the aliphatic-aromatic polyester in layer B is greater than 0.3 dl / g (measured using a Ubbelohde viscometer at 25°C for a 0.2 g / dl solution of CHCl3), preferably from 0.3 dl / g to 2 dl / g, and more preferably from 0.4 dl / g to 1.2 dl / g.

[0136] The content of aliphatic-aromatic polyester terminal acid groups in layer B is preferably less than 100 meq / kg, more preferably less than 60 meq / kg, and even more preferably less than 40 meq / kg.

[0137] The content of terminal acid groups can be measured as is known in the art, for example, as disclosed in WO2017216150.

[0138] The aliphatic-aromatic polyester in layer B is biodegradable. In the context of this invention, a biodegradable polymer means a polymer that is biodegradable according to EN 13432.

[0139] The aliphatic-aromatic polyester in layer B can be synthesized according to any method known in the art. In particular, it can be advantageously obtained using a polycondensation reaction.

[0140] Advantageously, the synthesis process can be carried out in the presence of a suitable catalyst. Suitable catalysts include, for example, organometallic tin compounds, such as stannate derivatives; titanium compounds, such as n-butyl titanate; aluminum compounds, such as triisopropylaluminum; antimony and zinc compounds; and zirconium compounds and mixtures thereof.

[0141] Relative to the sum of components vi. to x., the layer B composition comprises 0.1% to 50% by weight, preferably 5% to 35% by weight, of at least one naturally derived polymer (component vii). In the layer B composition, the naturally derived polymer is advantageously selected from starch, chitin, chitosan, alginate, proteins such as gluten, zein, casein, collagen, gelatin, natural gums, rosin acid, and derivatives thereof. Preferably, in the layer B composition, the naturally derived polymer is starch.

[0142] The term starch refers to all types of starch, namely flour, natural starch, hydrolyzed starch, allosteric starch, gelatinized starch, plasticized starch, thermoplastic starch, biofillers containing complex starches, or mixtures thereof. Starches from sources such as potatoes, corn, cassava, and peas are particularly suitable according to the invention.

[0143] Particularly advantageous are starches that are prone to conformational changes or have a high initial molecular weight, such as potato starch or corn starch.

[0144] Starch can exist as is or in chemically modified forms, such as starch esters with a degree of substitution between 0.2 and 2.5, hydroxypropylated starch, or starch modified with fatty chains.

[0145] In the case of allosteric starch, reference is made herein to the teachings contained in patents EP-0 118 240 and EP-0 327 505, which means that such starch is processed to be substantially free of so-called “Maltese crosses” under polarized light under an optical microscope and substantially free of so-called “ghosting” under an optical microscope with phase difference. Advantageously, the starch is allosterically modified by an extrusion process at a temperature of 110°C to 250°C, preferably 130°C to 180°C, preferably at a pressure of 0.1 MPa to 7 MPa, preferably 0.3 MPa to 6 MPa, preferably providing a specific energy greater than 0.1 kWh / kg during said extrusion.

[0146] The conformation of starch preferably occurs in the presence of one or more plasticizers selected from water and polyols having 2 to 22 carbon atoms, at a weight of 1% to 40% relative to the starch. The water may also be water naturally present in the starch. Among the polyols, preferred polyols are those having 1 to 20 hydroxyl groups and containing 2 to 6 carbon atoms, their ethers, thioethers, and organic and inorganic esters. Examples of polyols are glycerol, diglycerol, polyglycerol, pentaerythritol, ethoxylated polyglycerol, ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, sorbitol monoacetate, sorbitol oxide monoacetate, sorbitol sorbate, diethoxylated sorbitol, and mixtures thereof. In a preferred embodiment, the starch is conformationally modified in the presence of glycerol; or a mixture of plasticizers containing glycerol, more preferably containing 2% to 90% by weight of glycerol.

[0147] Preferably, the modified and crosslinked starch according to the invention contains 1% to 40% by weight of plasticizer relative to the weight of starch. When starch is present in the composition of layer B, it is preferably in the form of particles having a circular or elliptical cross-section, or additionally an arithmetic mean diameter of less than 1 micrometer measured along the long axis of the particles, and more preferably a quasi-elliptical cross-section with an average diameter of less than 0.5 μm.

[0148] Relative to the sum of components vi. to x., the composition of layer B comprises 0% to 40% by weight, preferably 2% to 30% by weight, of at least one polyhydroxyalkyl ester (component viiii.), preferably selected from lactic polyester, polycaprolactone, polyhydroxybutyrate, polyhydroxybutyrate-valerate, polyhydroxybutyrate-propionate, polyhydroxybutyrate-hexanoate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-propionate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-hexanoate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-3-polyhydroxybutyrate-hexanoate-dodecanoate-hydroxybutyrate-polyhydroxybutyrate-3-hydroxybutyrate. Preferably, the polyhydroxyalkyl ester comprises at least 80% by weight of one or more lactic polyesters.

[0149] 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 stereocomplexes, copolymers comprising more than 50 mol% of the lactic acid polyester, or mixtures thereof. Particularly preferred are lactic acid polyesters comprising at least 95 wt% repeating units derived from L-lactic acid or D-lactic acid or combinations thereof, having a molecular weight Mw greater than 50,000 and a shear viscosity (measured according to ASTM standard D3835 at T = 190°C, shear rate = 1000 / sec, D = 1 mm, L / D = 10).

[0150] In a particularly preferred embodiment of the invention, the lactic acid polyester comprises at least 95% by weight of units derived from L-lactic acid and <5% of repeating units derived from D-lactic acid, having a melting point in the range of 135°C to 180°C, a glass transition temperature (Tg) in the range of 55°C to 65°C, and an MFR (measured according to ISO 1133-1 at 190°C and 2.16 kg) in the range of 1 g / 10 min to 50 g / 10 min. Commercial examples of lactic acid polyesters having these properties include, for example, Ingeo. TM 4043D, 3250D and 6202D biopolymer products.

[0151] In the composition of layer B, relative to the sum of components vi. to x., there is at least one inorganic filler (component ix.) of 0% to 15% by weight, preferably 0% to 10% by weight, which is 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.

[0152] In a preferred embodiment of the invention, the inorganic filler in the composition of layer B comprises talc, calcium carbonate, or a mixture thereof, which are present in the form of particles with an arithmetic mean diameter of less than 10 micrometers when measured along the long axis of the particles.

[0153] Relative to the sum of components vi. to x., the composition of layer B also contains 0% to 5% by weight, preferably 0% to 0.5% by weight, at least one crosslinking agent and / or chain extender (component x.) to improve stability against hydrolysis.

[0154] The crosslinking agent and / or chain extender are selected from difunctional and / or polyfunctional compounds having the following groups: isocyanate group, peroxide group, carbodiimide group, isocyanurate group, etc. Azoline, epoxy, acid anhydride, or divinyl ether group or a mixture thereof.

[0155] Particularly preferred are mixtures of difunctional and / or polyfunctional compounds with isocyanate groups and difunctional and / or polyfunctional compounds with epoxy groups, and even more preferred are those containing at least 75% by weight of difunctional and / or polyfunctional compounds with isocyanate groups.

[0156] Compounds having difunctional and polyfunctional groups including an isocyanate group are preferably 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 ester diisocyanate, 2,4-cyclohexane diisocyanate, and 2,3-cyclohexane diisocyanate. The compounds include esters, 1-methyl-2,4-cyclohexyl diisocyanate, 1-methyl-2,6-cyclohexyl diisocyanate, bis-(isocyanatecyclohexyl)methane, 2,4,6-toluene triisocyanate, 2,4,4-diphenyl ether triisocyanate, polymethylene polyphenyl polyisocyanate, methylene diphenyl diisocyanate, triphenylmethane triisocyanate, 3,3'-dimethylmethylene-4,4-diisocyanate, 4,4'-methylene bis(2-methylphenyl isocyanate), hexamethylene 1,3-cyclohexyl diisocyanate, 1,2-cyclohexyl diisocyanate, and mixtures thereof. In a preferred embodiment, the compound containing the isocyanate group is 4,4-diphenylmethane diisocyanate.

[0157] As for difunctional and polyfunctional compounds with peroxy groups, 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, dihexadecylperoxydicarbonate, ditetradecylperoxydicarbonate, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, di(2-ethylhexyl)peroxydicarbonate, and mixtures thereof.

[0158] Preferably, the difunctional and polyfunctional compounds with carbodiimide groups used in the compositions according to the invention are selected from poly(cyclooctylcarbodiimide), poly(1,4-dimethylenecyclohexylcarbodiimide), poly(cyclohexylcarbodiimide), poly(ethylcarbodiimide), poly(butylcarbodiimide), poly(isobutylcarbodiimide), poly(nonylcarbodiimide), poly(dodecylcarbodiimide), poly(neopentylcarbodiimide), poly(1,4-dimethylenephenylcarbodiimide), and poly(2,2',6,6'-tetraisopropyldiphenylcarbodiimide). Poly(2,4,6-triisopropyl-1,3-phenylenecarbodiimide) Poly(2,6-diisopropyl-1,3-phenylenecarbodiimide) Poly(tolylcarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-biphenylcarbodiimide), poly(p-phenylcarbodiimide), poly(m-phenylcarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylcarbodiimide), poly(isophoronecarbodiimide), poly(cumenecarbodiimide), p-phenylbis(ethylcarbodiimide), 1,6-hexamethylenebis(ethylcarbodiimide), 1,8-octamethylenebis(ethylcarbodiimide), 1,10-decamethylenebis(ethylcarbodiimide), 1,12-dodecamethylenebis(ethylcarbodiimide), and mixtures thereof.

[0159] Examples of difunctional and polyfunctional compounds with epoxy groups that can be advantageously used in the compositions according to the invention include all polyepoxides derived from epoxidized oils and / or from styrene-glycidyl ether-methyl methacrylate or glycidyl ether-methyl methacrylate, having a molecular weight in the range of 1,000 to 10,000 and an epoxy number per molecule of 1 to 30, preferably 5 to 25, wherein the epoxides are selected from the group consisting of: diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, 2-epoxybutane, polyglycerol polyglycidyl ether, isoprene diepoxide and alicyclic diepoxide, 1,4-cyclohexanediethanol diglycidyl ether, glycidyl-2-methylphenyl ether, propoxylated triglycidyl ether, propoxylated triglycidyl ether, tetraglycidyl ether of m-xylenediamine and diglycidyl ether of bisphenol A, and mixtures thereof.

[0160] Together with those containing isocyanate groups, peroxide groups, carbodiimide groups, isocyanurate groups, etc., as mentioned above Difunctional and polyfunctional compounds with zoline, epoxy, anhydride, and divinyl ether groups can also be used with catalysts to increase the reactivity of the reactive groups. In the case of polyepoxides, fatty acid salts can be used, and even more preferably calcium stearate and zinc stearate.

[0161] In a particularly preferred embodiment of the invention, the crosslinking agent and / or chain extender comprises a compound with an isocyanate group, preferably 4,4-diphenylmethane diisocyanate; and / or a compound with a carbodiimide group; and / or a compound with an epoxide group, preferably styrene-glycidyl ether methyl methacrylate type.

[0162] In layer B, in addition to components vi. to x. described above, one or more other components may advantageously be present. In this case, layer B comprising the composition containing components vi. to x. is preferably one or more synthetic or naturally derived polymers that are different from components vi., vii. and viiii., and may be one or more other components.

[0163] The polymers that may be added to the composition of layer B are, or may not be, biodegradable synthetic or naturally derived polymers different from components vi., vii. and viiii. They are advantageously selected from the group consisting of: vinyl polymers, diacid polyesters different from polyester vi., polyamides, polyurethanes, polyethers, polyureas, polycarbonates and mixtures thereof.

[0164] Among vinyl polymers, preferred ones are polyethylene, polypropylene, copolymers thereof, polyvinyl alcohol, polyvinyl acetate, polyethyl vinyl acetate and polyvinyl alcohol, polystyrene, chlorinated vinyl polymers, and polyacrylates.

[0165] In addition to polyvinyl chloride, the chlorinated vinyl polymers also include polyvinylidene chloride, poly(vinyl chloride-vinyl acetate), poly(vinyl chloride-ethylene), 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 mol%. The polymers may be random copolymers, block copolymers, or alternating copolymers.

[0166] Regarding the polyamides in the compositions according to the invention, these are preferably selected from polyamide 6 and polyamide 6,6, polyamide 9 and polyamide 9,9, polyamide 10 and polyamide 10,10, polyamide 11 and polyamide 11,11, polyamide 12 and polyamide 12,12, and combinations thereof of the types 6 / 9, 6 / 10, 6 / 11 and 6 / 12, their blends, and both random copolymers and block copolymers. Preferably, the polycarbonate in the compositions according to the invention is selected from the group comprising: alkylene carbonates, more preferably ethylene carbonate, propylene carbonate, butylene carbonate, mixtures thereof, and both random copolymers and block copolymers.

[0167] Among the polyethers, those selected are those from polyethylene glycol, polypropylene glycol, polybutane glycol, copolymers thereof, and mixtures thereof with a molecular weight of 70,000 to 500,000.

[0168] Regarding diol polyesters that are different from polyester vi. in layer B, these preferred compositions include:

[0169] (g) a dicarboxylic acid component, which, relative to the total dicarboxylic acid component, comprises:

[0170] (g1) 20 mol% to 100 mol% of units derived from at least one aromatic dicarboxylic acid,

[0171] (g2) 0 mol% to 80 mol% of units derived from at least one saturated aliphatic dicarboxylic acid,

[0172] (g3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid;

[0173] (h) Diol component, relative to the total diol component, said diol component comprises:

[0174] (h1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol;

[0175] (h2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol.

[0176] Preferably, the g1 aromatic dicarboxylic acid, g2 saturated aliphatic dicarboxylic acid, g3 unsaturated aliphatic dicarboxylic acid, h1 saturated aliphatic diol, and h2 unsaturated aliphatic diol used in the polyester are selected from those used in the polyester vi. of layer B according to the invention.

[0177] In addition to the components mentioned above, the composition in layer B preferably also contains at least one other component selected from the following: plasticizer, UV stabilizer, lubricant, nucleating agent, surfactant, antistatic agent, pigment, flame retardant, compatibilizer, lignin, organic acid, antioxidant, mildew inhibitor, wax, processing aid, and preferably a polymer component selected from the following: vinyl polymer, glycol diacid polyester which is not one of the above aliphatic-aromatic polyesters, polyamide, polyurethane, polyether, polyurea or polycarbonate.

[0178] Regarding plasticizers, in addition to the plasticizers preferably used in the preparation of the above-mentioned allosteric starch, it is preferred that the composition of layer B according to the invention contains one or more plasticizers selected from the following: phthalates such as diisononyl phthalate, trimellitic esters such as trimellitic esters having C4-C20 monohydric alcohols preferably selected from n-octanol and n-decanol, and aliphatic esters having the following structures:

[0179] R1-OC(O)-R4-C(O)-[-O-R2-O-C(O)-R5-C(O)-]mO-R3, where:

[0180] R1 is selected from one or more of the following groups: H, saturated and unsaturated linear and branched alkyl residues of the C1-C24 type, and polyol residues esterified with C1-C24 monocarboxylic acids.

[0181] R2 comprises -CH2-C(CH3)2-CH2- and C2-Cg alkylene groups, and contains at least 50 mol% of the -CH2-C(CH3)2-CH2- group;

[0182] R3 is selected from one or more of the following groups: H, saturated and unsaturated linear and branched alkyl residues of the C1-C24 type, and polyol residues esterified with C1-C24 monocarboxylic acids.

[0183] R4 and R5 may be the same or different, and contain one or more C2-C22 alkylene groups, preferably C2-Cn alkylene groups, more preferably C4-C9 alkylene groups, and contain at least 50 mol% of C7 alkylene groups.

[0184] m is a number from 1 to 20, preferably from 2 to 10, and more preferably from 3 to 7. Preferably, in the ester, at least one of the Ri and / or R3 groups preferably comprises, relative to the total amount of Ri and / or R3 groups, at least 10 mol%, more preferably >20 mol%, and even more preferably >25 mol%, a polyol residue esterified with at least one of the following C1-C24 monocarboxylic acids: stearic acid, palmitic acid, 9-ketostearic acid, 10-ketostearic acid, and mixtures thereof. Examples of such aliphatic esters are described in Italian patent application MI2014A000030 and patent applications PCT / EP2015 / 050336 and PCT / EP2015 / 050338.

[0185] When present in layer B, the selected plasticizer is preferably present in less than 10% by weight of the total weight of the composition of layer B itself.

[0186] Preferably, the lubricant is selected from fatty acid esters and metal salts, such as zinc stearate, calcium stearate, aluminum stearate, and acetyl stearate. Preferably, the composition of layer B according to the invention contains less than 1% by weight, more preferably less than 0.5% by weight, of lubricant relative to the total weight of the composition of layer B.

[0187] Examples of nucleating agents include sodium saccharin, calcium silicate, sodium benzoate, calcium titanate, boron nitride, isotactic polypropylene, or low molecular weight PLA. These additives are preferably added in amounts of 10% by weight or less, more preferably 2% to 6% by weight, relative to the total weight of the composition. Pigments, such as titanium dioxide, clay, copper phthalocyanine, silicates, iron oxides and hydroxides, carbon black, and magnesium oxide, may also be added if desired. These additives are preferably added in amounts of 10% by weight or less.

[0188] Preferably, the multilayer film according to the invention is characterized in that the ratio of renewable carbon to total organic carbon content (renewable percentage), as measured according to ASTM D6866, is greater than 15%, preferably greater than 40%, more preferably greater than 50%, and even more preferably greater than 60%. According to the invention, products that can be considered renewable sources are those that are inherently renewable and derived from inexhaustible sources in human life, and therefore their use will not adversely affect future generations' access to natural resources. Examples of renewable source monomers are sebacic acid, succinic acid, 2,5-furandicarboxylic acid, azelaic acid, and 1,4-butanediol.

[0189] The multilayer film according to the invention comprises at least one layer A and at least one layer B, preferably characterized by a selected interrelationship between A / B and A / B / A, wherein layers A and B are different from each other. The multilayer film according to the invention may advantageously comprise one or more layers A and one or more layers B, as well as additional layers, such as connecting layers or barrier layers, or metal films. In the multilayer film according to the invention, the ratio of the total number of layers A to the total number of layers B is 0.05 to 1.2. Preferably, in the multilayer film according to the invention, the ratio of the total amount of layers A to the total amount of layers B is 0.1 to 0.6. The multilayer film according to the invention has layers of an A / B type and preferably an A / B / A arrangement, with a total thickness in which the sum of the thicknesses of layers A is less than the thickness of layers B, preferably less than B / 2, more preferably less than B / 3.

[0190] The total thickness of the multilayer film according to the invention is advantageously less than 50 micrometers, more preferably less than 15 micrometers, and even more preferably less than 13 micrometers.

[0191] The thickness of the layer can be advantageously measured on the fracture surface using an electron microscope in liquid nitrogen.

[0192] In any case, there may be another layer that is arranged in an intermediate position relative to layers A and B (arranged as A / C / B, where C is another layer) or not in an intermediate position (arranged as A / B / C or C / A / B, where C is another layer).

[0193] The multilayer film according to the invention can be produced by any method known in the art, such as co-extrusion, coating / coating, or lamination. In a preferred embodiment, the multilayer film according to the invention can be obtained by co-extrusion, preferably in conjunction with a bubble film-forming method.

[0194] The specific equipment and process conditions used to produce the multilayer films according to the invention, such as for co-extrusion and film formation, depend on the composition and number of layers of the multilayer film to be produced. Through specific combinations of components and layers, the multilayer films according to the invention possess an excellent balance between high levels of biodegradability, mechanical properties, and considerable optical transparency. This makes them particularly suitable for producing a wide range of articles, such as various types of packaging including the multilayer films, especially bags for transporting goods and bags for food packaging, such as bags for fruits and vegetables. They are also particularly suitable for cover sheets.

[0195] Regarding optical properties (referring to films with a thickness of less than 13 micrometers), a transmittance value greater than 90%, more preferably greater than 91%; a haze (turbidity) value less than 65%, more preferably less than 55%, even more preferably less than 45%; and a sharpness (clarity) value greater than 20%, more preferably greater than 40%, even more preferably greater than 55% (measured according to ASTM D1003), which makes the multilayer film according to the invention particularly suitable for the above-mentioned applications.

[0196] The multilayer membrane according to the invention is capable of decomposing under home composting conditions according to UNI 11355. Preferably, the multilayer membrane is capable of decomposing under home composting conditions according to UNI 11355 when it is characterized by a total thickness of less than 15 micrometers, preferably less than 13 micrometers.

[0197] The invention will now be illustrated by way of several embodiments, which are not intended to be limiting. Example

[0198] Component i: Poly(butylene adipate-copolymer-butylene terephthalate), with a terephthalic acid content of 47.3 mol% relative to the total dicarboxylic acids, an MFR of 4.8 g / 10 min (@190 °C, 2.16 kg), and an acidity of 37 meq / kg.

[0199] Component ii-1: Poly(butylene succinate-copolymer-butylene azelaate), containing 25 mol% azelaic acid relative to the sum of succinic acid and azelaic acid, MFR 5.9 g / 10 min (@90 °C, 2.16 kg), and acidity 46 meq / kg.

[0200] Component ii-2: Poly(butylene succinate-copolymer-butylene azelaate), containing 20 mol% azelaic acid relative to the sum of succinic acid and azelaic acid, MFR 5.0 g / 10 min (@190 °C, 2.16 kg), and acidity 50 meq / kg.

[0201] Component iii: Polylactic acid (“PLA”) Ingeo 3251D, MFR 41g / 10min (@190℃, 2.16kg).

[0202] Component v: a random copolymer based on styrene-alkyl acrylate-glycidyl methacrylate with Mw of 6800 and 10 epoxy per molecule.

[0203] Component vi: Poly(butylene adipate-copolymer-butylene azelaate-copolymer-butylene terephthalate), containing 15 mol% azelaic acid relative to the sum of adipic acid and azelaic acid, containing 47.6 mol% terephthalic acid relative to the sum of total dicarboxylic acids, MFR 4.4 g / 10 min (@190 °C, 2.16 kg); and acidity 39 meq / kg.

[0204] Component vii: Natural corn starch and plasticizer (76.4% by weight of natural corn starch, 13.9% by weight of polyglycerol and 9.7% by weight of added water).

[0205] Component viii: Polylactic acid (“PLA”) Ingeo 4043D, MFR 2.5g / 10min (@190℃, 2.16kg).

[0206] Component x: a random copolymer based on styrene-alkyl acrylate-glycidyl methacrylate with Mw of 1400 and 33 epoxy per molecule.

[0207] Example 1 - A three-layer membrane with arrangement A / B / A

[0208] Preparation of Composition A (Layer A): The composition described in Table 1 was fed into an OMC EBV60 / 36 twin-screw extruder operating under the following conditions:

[0209] Screw diameter (D) = 58 mm;

[0210] L / D = 36;

[0211] Screw speed = 140 rpm;

[0212] Temperature distribution = 60 - 150 - 180 - 210 × 4 - 150 × 2℃;

[0213] Production capacity: 40 kg / hour;

[0214] Vacuum degassing is performed in zone 8 out of 10.

[0215] Preparation of Composition B (Layer B): The compositions described in Table 1 were fed into a twin-screw extruder, model OMCEBV 60 / 36, operating under the following conditions:

[0216] Screw diameter (D) = 58 mm;

[0217] L / D = 36;

[0218] Screw speed = 160 rpm;

[0219] Temperature distribution = 60 - 150 - 180 - 210 × 4 - 150 × 2℃;

[0220] Production capacity: 46 kg / hour;

[0221] Vacuum degassing is performed in zone 8 out of 10.

[0222] Compositions A and B (Table 1) were then simultaneously fed into a co-extruder to form a three-layer blown film with an A / B / A arrangement. For this purpose, composition A was fed at a flow rate of 3 kg / h into a first extruder with a screw diameter of 35 mm, an L / D ratio of 30, operating at 10 rpm, and a heat distribution of 100-170×4, and at a flow rate of 3 kg / h into a second extruder characterized by a screw diameter of 35 mm, an L / D ratio of 30, operating at 10 rpm, and a heat distribution of 100-170×4. Composition B was fed at a flow rate of 24 kg / h into an extruder with a screw diameter of 40 mm, an L / D ratio of 30, operating at 72 rpm, and a heat distribution of 80-145×4. The two molten compositions are combined in a co-extrusion blow molding head with an air gap of 0.9 mm and an L / D of 9, set at 170°C, thereby feeding a multilayer structure into a film-forming process running at a blow ratio of 4.5 and a draw ratio of 16.8.

[0223] The resulting films (total 12 micrometers, 20% layer A (divided equally between two layers), 80% layer B) were then characterized in terms of decomposition properties (Table 2), mechanical properties (Table 3), and optical properties (Table 4).

[0224] Example 2 - A three-layer membrane with arrangement A / B / A

[0225] Preparation of Composition A (Layer A) and Composition B (Layer B): Composition A and Composition B were fed into an OMC EBV60 / 36 twin-screw extruder operating under the operating conditions reported for Composition A and Composition B in Example 1.

[0226] Compositions A and B (Table 1) were then simultaneously fed into a co-extruder to form a three-layer blown film with an A / B / A arrangement. For this purpose, composition A was fed at a flow rate of 3.2 kg / h into a first extruder with a screw diameter of 35 mm, an L / D ratio of 30, operating at 11 rpm, and a heat distribution of 100-170×4, and at a flow rate of 3.1 kg / h into a second extruder characterized by a screw diameter of 35 mm, an L / D ratio of 30, operating at 10 rpm, and a heat distribution of 100-170×4. Composition B was fed at a flow rate of 23.7 kg / h into an extruder with a screw diameter of 40 mm, an L / D ratio of 30, operating at 70 rpm, and a heat distribution of 80-145×4. The two molten compositions are combined in a co-extrusion blow molding head with an air gap of 0.9 mm and an L / D of 9, set at 170°C, thereby feeding a multilayer structure into a film-forming process running at a blow ratio of 4.5 and a draw ratio of 15.6.

[0227] The resulting films (total 13 μm, 20% layer A (divided equally between two layers), 80% layer B) were then characterized in terms of decomposition properties (Table 2), mechanical properties (Table 3), and optical properties (Table 4).

[0228] Example 3 (Comparative) has a three-layer membrane with an arrangement of A / B / A.

[0229] Preparation of Composition A (Layer A) and Composition B (Layer B): These were fed into an OMC EBV60 / 36 twin-screw extruder operating under the operating conditions reported for Composition A and Composition B in Example 1.

[0230] Compositions A and B (Table 1) were then simultaneously fed into a co-extruder to form a three-layer blown film with an A / B / A arrangement. For this purpose, composition A was fed at a flow rate of 3 kg / h into a first extruder with a screw diameter of 35 mm, an L / D ratio of 30, operating at 10 rpm, and a heat distribution of 100-170×4, and at a flow rate of 3.2 kg / h into a second extruder characterized by a screw diameter of 35 mm, an L / D ratio of 30, operating at 12 rpm, and a heat distribution of 100-170×4. Composition B was fed at a flow rate of 23.8 kg / h into an extruder with a screw diameter of 40 mm, an L / D ratio of 30, operating at 73 rpm, and a heat distribution of 80-145×4. The two molten compositions are combined in a co-extrusion blow molding head with an air gap of 0.9 mm and an L / D of 9, set at 170°C, thereby feeding a multilayer structure into a film-forming process running at a blow ratio of 4.5 and a draw ratio of 16.8.

[0231] The resulting films (total 12 μm, 20% layer A (divided equally between two layers), 80% layer B) were then characterized in terms of decomposition properties (Table 2), mechanical properties (Table 3), and optical properties (Table 4).

[0232] Table 1. Composition of the mixture (wt%)

[0233]

[0234]

[0235] Table 2 Results of decomposition characteristics under home composting conditions (UNI 11355)

[0236] Decomposition under home composting conditions was performed according to standard UNI 11355 App.A "Biodegradable plastic articles in home composting - Requirements and test methods".

[0237] The degree of membrane decomposition was determined by placing the sample on a glass slide measuring approximately 50 mm × 50 mm. The slide was placed on top of a first layer of waste approximately 4 cm thick, followed by a second layer of waste approximately 2 cm thick. The waste consisted of 98% compost, 1% starch, and 1% other materials. Qualitative tracking of the decomposition was performed (visual observation and photographs).

[0238] Example 1 153 Example 2 154 Comparison 1 179

[0239] Table 3 Results of mechanical properties and tear strength

[0240]

[0241] Table 4 Optical property results

[0242]

Claims

1. A multilayer film comprising at least a first layer A and at least a second layer B, wherein layer A comprises: i) 97% to 60% by weight of at least one aliphatic-aromatic polyester relative to the sum of components i to v, said aliphatic-aromatic polyester comprising: a) A dicarboxylic acid component, which, relative to the total amount of the dicarboxylic acid component, comprises: a1) 30 mol% to 70 mol% of units derived from at least one aromatic dicarboxylic acid; a2) 70 mol% to 30 mol% of units derived from at least one saturated aliphatic dicarboxylic acid; a3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid; b) A diol component, which, relative to the total diol component, comprises: b1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol; b2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol; ii) 3% to 40% by weight of at least one aliphatic polyester relative to the sum of components i to v, said aliphatic polyester comprising: c) A dicarboxylic acid component, which, relative to the total amount of the dicarboxylic acid component, comprises: c1) 70 mol% to 97 mol% of units derived from succinic acid; c2) 3 mol% to 30 mol% of units derived from at least one saturated dicarboxylic acid other than succinic acid; d) Diol component, relative to the total diol component, said diol component comprises: d1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol; d2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol; iii) at least one polyhydroxyalkanoate, from 0% to 37% by weight relative to the sum of components i to v; iv) 0% to 10% by weight of at least one inorganic filler relative to the sum of components i to v; v) Relative to the sum of components i to v, 0% to 5% by weight of at least one crosslinking agent and / or chain extender, said crosslinking agent and / or chain extender comprising at least one polyfunctional compound selected from: isocyanate, peroxide, carbodiimide, isocyanurate, Azoline, epoxide, acid anhydride, divinyl ether and mixtures thereof; The condition is that, relative to components i through v, if component iii is 0, then component iv must be greater than 0, and component (i) must be included in the composition at a weight percentage of 96.9% to 60%; and layer B comprises: vi) 99.9% to 50% by weight of at least one aliphatic-aromatic polyester relative to the sum of components vi. to x., said aliphatic-aromatic polyester comprising: e) A dicarboxylic acid component, which, relative to the total amount of the dicarboxylic acid component, comprises: e1) 30 mol% to 70 mol% of units derived from at least one aromatic dicarboxylic acid; e2) 70 mol% to 30 mol% of units derived from at least one saturated aliphatic dicarboxylic acid; e3) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic dicarboxylic acid; f) A diol component, relative to the total diol component, comprising: f1) 95 mol% to 100 mol% of units derived from at least one saturated aliphatic diol; f2) 0 mol% to 5 mol% of units derived from at least one unsaturated aliphatic diol; vii) 0.1% to 50% by weight of at least one polymer of natural origin relative to the sum of components vi. to x. viii) relative to the sum of components vi. to x., at least one polyhydroxyalkanoate, from 0% to 40% by weight; ix) 0% to 15% by weight of at least one inorganic filler relative to the sum of components vi. to x. x) 0% to 5% by weight of at least one crosslinking agent and / or chain extender relative to the sum of components vi. to x., said crosslinking agent and / or chain extender comprising at least one polyfunctional compound selected from: isocyanate, peroxide, carbodiimide, isocyanurate, Azoline, epoxide, acid anhydride, divinyl ether and mixtures thereof.

2. The multilayer film according to claim 1, wherein component a1 is 40 mol% to 60 mol% of units derived from at least one aromatic dicarboxylic acid.

3. The multilayer film according to claim 1, wherein component a2 is 60 mol% to 40 mol% of units derived from at least one saturated aliphatic dicarboxylic acid.

4. The multilayer film according to claim 1, wherein relative to components i to v, if component iii is 0, then component iv is 0.1% to 8% by weight, and component (i) must be included in 96.9% to 60% by weight.

5. The multilayer film according to claim 1, wherein relative to components i to v, if component iii is 0, then component iv is 3% to 5% by weight, and component (i) must be included in 96.9% to 60% by weight.

6. The multilayer film according to claim 1, wherein the aromatic dicarboxylic acid in component a1 is selected from phthalic acid-type aromatic dicarboxylic acids; heterocyclic dicarboxylic acid aromatic compounds; and one or more of their esters and salts.

7. The multilayer film according to claim 6, wherein the phthalic acid-type aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.

8. The multilayer film according to claim 6, wherein the phthalic acid-type aromatic dicarboxylic acid is terephthalic acid.

9. The multilayer film according to claim 6, wherein the heterocyclic dicarboxylic acid aromatic compound is 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, or 3,4-furandicarboxylic acid.

10. The multilayer film according to claim 6, wherein the heterocyclic dicarboxylic acid aromatic compound is 2,5-furandicarboxylic acid.

11. The multilayer film according to claim 6, wherein the aromatic dicarboxylic acid in component a1 comprises: From 1% to 99% of terephthalic acid, its esters or salts, on a molar basis; from 99% to 1% of 2,5-furandicarboxylic acid, its esters or salts, on a molar basis.

12. The multilayer film according to claim 6, wherein the aromatic dicarboxylic acid in component a1 comprises: On a molar basis, 5% to 95% of terephthalic acid, its esters or salts; on a molar basis, 95% to 5% of 2,5-furandicarboxylic acid, its esters or salts.

13. The multilayer film according to claim 6, wherein the aromatic dicarboxylic acid in component a1 comprises: On a molar basis, 10% to 80% of terephthalic acid, its esters or salts; on a molar basis, 90% to 20% of 2,5-furandicarboxylic acid, its esters or salts.

14. The multilayer film according to any one of claims 1 to 13, wherein the saturated aliphatic dicarboxylic acid in component a2 is selected from saturated C2-C24 dicarboxylic acids; their C1-C24 alkyl esters; and one or more of their salts.

15. The multilayer film according to claim 14, wherein the saturated C2-C24 dicarboxylic acid is a saturated C4-C13 dicarboxylic acid.

16. The multilayer film according to claim 14, wherein the saturated C2-C24 dicarboxylic acid is a saturated C4-C11 dicarboxylic acid.

17. The multilayer film according to claim 14, wherein the C1-C24 alkyl ester is a C1-C4 alkyl ester.

18. The multilayer film according to claim 14, wherein the saturated aliphatic dicarboxylic acid in component a2 is selected from succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, octadecanoic acid, and their C1-C24 alkyl esters.

19. The multilayer film according to claim 18, wherein the saturated aliphatic dicarboxylic acid in component a2 comprises a mixture containing at least 50 mol% of one or more of the following components: succinic acid, adipic acid, azelaic acid, sebacic acid, tridecanoic acid; their C1-C24 alkyl esters; and their salts.

20. The multilayer film according to claim 18, wherein the saturated aliphatic dicarboxylic acid in component a2 comprises a mixture containing more than 60 mol% of one or more of the following components: succinic acid, adipic acid, azelaic acid, sebacic acid, tridecanoic acid; their C1-C24 alkyl esters; and their salts.

21. The multilayer film according to claim 18, wherein the saturated aliphatic dicarboxylic acid in component a2 comprises a mixture containing more than 65 mol% of one or more of the following components: succinic acid, adipic acid, azelaic acid, sebacic acid, tridecanoic acid; their C1-C24 alkyl esters; and their salts.

22. The multilayer film according to any one of claims 19 to 21, wherein the C1-C24 alkyl ester is a C1-C4 alkyl ester.

23. The multilayer film according to any one of claims 1 to 13, wherein, relative to the sum of components i to v, component ii of layer A comprises 3 wt% to 30 wt% of an aliphatic polyester, said aliphatic polyester comprising a dicarboxylic acid component, said dicarboxylic acid component comprising 70 mol% to 97 mol% of units derived from succinic acid relative to the total amount of said dicarboxylic acid component.

24. The multilayer film according to any one of claims 1 to 13, wherein, relative to the sum of components i to v, component ii of layer A comprises 4 wt% to 25 wt% of an aliphatic polyester, said aliphatic polyester comprising a dicarboxylic acid component, said dicarboxylic acid component comprising 70 mol% to 97 mol% of units derived from succinic acid relative to the total amount of said dicarboxylic acid component.

25. The multilayer film according to any one of claims 1 to 13, wherein, relative to the sum of components i to v, component ii of layer A comprises 4 wt% to 12 wt% of an aliphatic polyester, said aliphatic polyester comprising a dicarboxylic acid component, said dicarboxylic acid component comprising 70 mol% to 97 mol% of units derived from succinic acid relative to the total amount of said dicarboxylic acid component.

26. The multilayer film according to any one of claims 1 to 13, wherein the saturated aliphatic dicarboxylic acid in component c2, other than succinic acid, is selected from saturated dicarboxylic acids C5-C24; their C1-C24 alkyl esters; and one or more of their salts.

27. The multilayer film according to claim 26, wherein the saturated dicarboxylic acid C5-C24 is a saturated dicarboxylic acid C5-C13.

28. The multilayer film according to claim 26, wherein the saturated dicarboxylic acid C5-C24 is a saturated dicarboxylic acid C7-C11.

29. The multilayer film according to claim 26, wherein the C1-C24 alkyl ester is a C1-C4 alkyl ester.

30. The multilayer film according to claim 26, wherein the saturated aliphatic dicarboxylic acid in component c2, other than succinic acid, is selected from 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, and their C1-24 alkyl esters.

31. The multilayer film according to claim 26, wherein component c2 is azelaic acid.

32. The multilayer film according to any one of claims 1 to 13, wherein, relative to the sum of components i to v, component iii of layer A comprises 5% to 37% by weight of polyhydroxyalkanoate.

33. The multilayer film according to any one of claims 1 to 13, wherein component iv. of layer A is present in an amount of 0.1% to 8% by weight relative to the sum of components i. to v.

34. The multilayer film according to any one of claims 1 to 13, wherein component iv. of layer A is present in 3% to 5% by weight relative to the sum of components i. to v.

35. The multilayer membrane according to claim 33, wherein component iv. is selected from kaolin, barite, clay, talc, calcium carbonate, magnesium carbonate, iron carbonate, lead carbonate, aluminum hydroxide, diatomaceous earth, aluminum sulfate, barium sulfate, silicon dioxide, mica, titanium dioxide and wollastonite.

36. The multilayer film according to any one of claims 1 to 13, wherein component v. is present in an amount of 0.1% to 0.5% by weight relative to the sum of components i. to v.

37. The multilayer film according to any one of claims 1 to 13, wherein in layer B, the aromatic dicarboxylic acid in component e1 is selected from phthalic acid-type aromatic dicarboxylic acids; heterocyclic dicarboxylic acid aromatic compounds; and one or more of their esters and salts.

38. The multilayer film according to claim 37, wherein the phthalic acid-type aromatic dicarboxylic acid is terephthalic acid or isophthalic acid.

39. The multilayer film according to claim 37, wherein the phthalic acid-type aromatic dicarboxylic acid is terephthalic acid.

40. The multilayer film according to claim 37, wherein the heterocyclic dicarboxylic acid aromatic compound is 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid or 3,4-furandicarboxylic acid.

41. The multilayer film according to claim 37, wherein the heterocyclic dicarboxylic acid aromatic compound is 2,5-furandicarboxylic acid.

42. The multilayer film according to claim 37, wherein the aromatic dicarboxylic acid in component e1 comprises: 1% to 99% terephthalic acid, its ester or salt, on a molar basis; and 99% to 1% 2,5-furandicarboxylic acid, its ester or salt, on a molar basis.

43. The multilayer film according to claim 37, wherein the aromatic dicarboxylic acid in component e1 comprises: 5% to 95% terephthalic acid, its ester or salt, on a molar basis; and 95% to 5% 2,5-furandicarboxylic acid, its ester or salt, on a molar basis.

44. The multilayer film according to claim 37, wherein the aromatic dicarboxylic acid in component e1 comprises: 10% to 80% terephthalic acid, its ester or salt, on a molar basis; and 90% to 20% 2,5-furandicarboxylic acid, its ester or salt, on a molar basis.

45. The multilayer film according to any one of claims 1 to 13, wherein in layer B, the saturated aliphatic dicarboxylic acid in component e2 is selected from saturated C2-C24 dicarboxylic acids; one or more of their C1-C24 alkyl esters and their salts.

46. ​​The multilayer film according to claim 45, wherein the saturated C2-C24 dicarboxylic acid is a saturated C4-C13 dicarboxylic acid.

47. The multilayer film according to claim 45, wherein the saturated C2-C24 dicarboxylic acid is a saturated C4-C11 dicarboxylic acid.

48. The multilayer film according to claim 45, wherein the C1-C24 alkyl ester is a C1-C4 alkyl ester.

49. The multilayer film according to claim 45, wherein the saturated aliphatic dicarboxylic acid in component e2 is selected from one or more of succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, octadecanoic acid, their C1-24 alkyl esters and their salts.

50. The multilayer film according to claim 49, wherein the saturated aliphatic dicarboxylic acid in component e2 consists of adipic acid and azelaic acid, and contains azelaic acid in an amount of 5 mol% to 70 mol% relative to the sum of adipic acid and azelaic acid.

51. The multilayer film according to claim 49, wherein the saturated aliphatic dicarboxylic acid in component e2 consists of adipic acid and azelaic acid, and contains azelaic acid in an amount of 10 mol% to 55 mol% relative to the sum of adipic acid and azelaic acid.

52. The multilayer film according to claim 49, wherein the saturated aliphatic dicarboxylic acid in component e2 consists of adipic acid and azelaic acid, and comprises azelaic acid in an amount of 12 mol% to 45 mol% relative to the sum of adipic acid and azelaic acid.

53. The multilayer film according to any one of claims 1 to 13, wherein in layer B, component vii. is present in an amount of 5% to 35% by weight relative to the sum of components vi. to x.

54. The multilayer film according to any one of claims 1 to 13, wherein layer A and layer B have an A / B type and / or A / B / A type layer arrangement.

55. The multilayer film according to any one of claims 1 to 13, characterized in that... The multilayer membrane is capable of decomposing in less than 180 days under home composting conditions according to UNI 1135.

56. A package comprising a multilayer film according to any one of claims 1 to 55.

57. The packaging according to claim 56, selected from bags for transporting articles and bags for food packaging.

58. The packaging according to claim 56, selected from bags for fruits and vegetables.

Images