Biodegradable polymer blends and uses thereof

Abstract

The present invention provides 10 to 80 wt. % of at least one biodegradable polyester a) selected from the group consisting of aliphatic-aromatic polyesters different from polymers b) and c), aliphatic polyesters, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 18 to 88 wt. % of at least one polymer b) selected from the group consisting of polyhydroxyalkanoates, polylactides, polyglycolic acids, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 2 to 72% by weight, based on the total weight of polyester a), polymer b) and polycaprolactone c), of at least one polycaprolactone c) having a viscosity number, determined in accordance with DIN 53728-3:1985-1, of at least 110 ml / g, in particular at least 150 ml / g, preferably at least 200 ml / g, in particular at least 250 ml / g; Including, The present invention relates to a biodegradable polymer blend based on biodegradable aliphatic-aromatic polyesters and / or aliphatic polyesters, wherein the total weight of polyester a), polymer b), and polycaprolactone c) is at least 50% by weight, based on the total weight of the blend. The present invention relates to the use of the blends for coating substrates or for producing rigid packaging articles, to mono- or multi-layer films comprising at least one layer comprising a biodegradable polymer blend as defined below, and to a method for coating a substrate layer.The present invention also relates to laminates and packaging materials comprising at least one mono- or multi-layer film comprising at least one layer comprising a biodegradable polymer blend as defined below.

Description

[Technical Field]

[0001] The present invention relates to biodegradable polymer blends based on biodegradable aliphatic-aromatic polyesters and / or aliphatic polyesters, their use for coating substrates or for producing rigid packaging articles, mono- or multi-layer films comprising at least one layer comprising the biodegradable polymer blend defined below, and a method for coating a substrate layer.

[0002] The present invention also relates to laminates and packaging materials comprising at least one monolayer or multilayer film, the at least one layer of which comprises a biodegradable polymer blend as defined below.

[0003] Background technology Extrusion coating, extrusion lamination, and adhesive lamination are standard and versatile coating techniques for applying polymeric films onto substrates such as paper, paperboard, corrugated board, aluminum foil, cellulose, nonwovens, or plastic films. Products typically made with extrusion coating and lamination are lidstock, candy wrappers, snack food bags, medical packaging, condiment packages, soup pouches, toothpaste tubes, frozen food boxes, ready-meal trays, and cable wrap.

[0004] In the extrusion coating process, an extruder converts a solid coating compound into a melt at the appropriate temperature required for coating. The plasticized coating compound is pressed through a sheeting die and transferred directly onto the substrate to be coated.

[0005] The coating materials typically used in extrusion coating are thermoplastic polymers such as polyethylene, polypropylene, thermoplastic elastomers, and their polymer / additive compounds. However, such thermoplastic polymers have certain drawbacks. For example, polyethylene-based extrusion coatings generate excessive odor, cause aldehyde emissions, and require extrusion temperatures that are incompatible with coextrusion with heat-sensitive polymers. Furthermore, they are often neither compostable nor biodegradable.

[0006] Compostable plastics applied to extrusion paper coatings are available on the market, such as polylactide (PLA) or blends of PLA with poly(butylene adipate terephthalate) (PBAT), commercially available from BASF under the trade name ecovio®. There have been several descriptions of biodegradable polymer films containing PLA and PBAT.

[0007] Chinese Patent No. 107793720 describes a fully biodegradable plastic film suitable for peanut mulching and its preparation method. The plastic film consists of the following components: 100 parts PLA, 70-90 parts PBAT, 0.5-1.0 parts nucleating agent, 5-10 parts complex hydrolysis inhibitor, 0.5-1.5 parts complex UV inhibitor, 3-6 parts molecular weight regulator, and 20-30 parts flexibility modifier. The flexibility modifier used is low-molecular-weight polycaprolactone with an average molecular weight of 1000-3000.

[0008] EP 1227129 describes a biodegradable polyester blend containing an aromatic-aliphatic polyester (A) such as PBAT, an aliphatic polyester (B) such as polybutylene sebacate or poly-ε-caprolactone, and a polylactic acid polymer (C). The blend contains 40 to 70% by weight of (A), based on the total weight of (A) and (B), and 6 to 30% by weight of (C), based on the total weight of (A), (B), and (C).

[0009] WO 02 / 059198 describes a biodegradable polyester blend containing (A) a polyhydroxy acid of the poly-ε-caprolactone type and its copolymers, (B) an aliphatic polyester such as polybutylene sebacate, and (C) a polymer of polylactic acid, which blend contains 40 to 70% by weight of (A), based on the total weight of (A) and (B), and 2 to 30% by weight of (C), based on the total weight of (A), (B), and (C).

[0010] Summary of the Invention However, there is still a need to improve the properties of extrusion coatings that apply compostable or biodegradable polymers with respect to adhesion to paper substrates, which is an important criterion for evaluating the quality of extrusion coatings. At the same time, the applied compostable or biodegradable polymer should be suitable for high coating line speeds, which correlates with the applied polymer coating weight and determines the practicality and profitability of the extrusion coating process.

[0011] It was therefore an object of the present invention to provide biodegradable polymer blends that are better suited for extrusion coating, in particular biodegradable polymer blends that exhibit better adhesion to paper substrates while at the same time being suitable for high coating line speeds.

[0012] It has surprisingly been found that modifying a biodegradable polymer blend containing at least one biodegradable polyester by adding polycaprolactone (PCL) having a specific molecular weight improves adhesion at high coating line speeds.

[0013] Therefore, the present invention provides 10 to 80 wt. % of at least one biodegradable polyester a) selected from the group consisting of aliphatic-aromatic polyesters different from polymers b) and c), aliphatic polyesters, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 18 to 88 wt. % of at least one polymer b) selected from the group consisting of polyhydroxyalkanoates, polylactides, polyglycolic acids, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 2 to 72% by weight, based on the total weight of polyester a), polymer b) and polycaprolactone c), of at least one polycaprolactone c) having a viscosity number, determined in accordance with DIN 53728-3:1985-1, of at least 110 ml / g, in particular at least 150 ml / g, preferably at least 200 ml / g, in particular at least 250 ml / g; Including, The biodegradable polymer blend relates to a biodegradable polymer blend in which the total weight of polyester a), polymer b), and polycaprolactone c) is at least 50% by weight, based on the total weight of the blend.

[0014] The present invention entails several advantages.

[0015] The biodegradable polymer blends according to the present invention improve the adhesion of coatings to substrates without adversely affecting processability.

[0016] The biodegradable polymer blend according to the present invention provides good flowability.

[0017] The biodegradable polymer blends according to the invention have a lower tendency to edge rippling compared to known solutions in extrusion coating, which results in the possibility to use higher web speeds in the coating process and achieve significant savings in material.

[0018] The biodegradable polymer blends according to the present invention protect substrates from oil, grease, and moisture, and their weldability with themselves and with paper, cardboard, and metal allows for the production of, for example, coffee cups, beverage cartons, or frozen food cartons.

[0019] Very good biodegradability of the entire system. Industrially and domestically compostable according to DIN EN 13432 / NFT 51800 if suitable substrates are used.

[0020] Thus, a second aspect of the present invention relates to a monolayer or multilayer film comprising or consisting of at least one polymer layer containing or consisting of a biodegradable polymer blend according to the present invention.A further aspect of the present invention relates to a laminate comprising or consisting of at least one monolayer or multilayer film comprising or consisting of at least one layer comprising or consisting of a biodegradable polymer blend according to the present invention and a substrate onto which the film is laminated.

[0021] Furthermore, a further aspect of the present invention is a material selected from packaging; paper and cardboard cups and plates; carrier bags; paper adhesive tape; paper labels; flower pots; and plant pots, comprising at least one film as defined below or laminate as defined below; A method for producing a rigid packaging article, the method comprising the step of forming by thermoforming or injection molding a polymer blend as defined herein and hereinafter, or a mono- or multi-layer sheet or laminate comprising a polymer blend as defined herein and hereinafter. Regarding.

[0022] Further aspects of the present invention also relate to the use of the biodegradable polymer blend according to the invention for coating a substrate layer or for producing a rigid packaging article, and to a method for coating a substrate layer, comprising the steps a) of providing a substrate layer and B) of coating the substrate with one or more polymer layers, at least one of the layers comprising or consisting of the biodegradable polymer blend of the present invention.

[0023] MODE FOR CARRYING OUT THE INVENTION Here, and throughout this specification, the terms "compostable" and "biodegradable" are used interchangeably.

[0024] Here, and throughout this specification, the terms "polylactic acid" and "polylactide" are used interchangeably.

[0025] Here, and throughout this specification, the terms "wt.-%" and "% by weight" are used interchangeably.

[0026] "Molecular weight Mn" or "molar mass Mn" is the number-average molecular weight or molar mass. "Molecular weight Mw" or "molar mass Mw" is the weight-average molecular weight or molar mass. Unless otherwise specified, Mn and Mw were determined by GPC with a refractive index (RI) detector using a mixture of hexafluoroisopropanol and 0.05% potassium trifluoroacetate as the eluent (temperature: 40°C, flow rate: 1 mL / min) and polymethyl methacrylate of the defined molecular weight as the calibration standard.

[0027] Here and throughout this specification, melt volume rate (MVR) refers to the value determined according to EN ISO 1133 (190°C, 2.16 kg weight) unless otherwise stated.

[0028] The MVR of polycaprolactone was determined at 160°C and 2.16 kg weight according to EN ISO 1133. The sample to be measured is usually dried at 80°C and 100 mbar for 3 hours. The measurement can be carried out using a Goettfert MI-ROBO device.

[0029] Here, and throughout this specification, the acid number (AN) is determined according to the following method: 1.0 g of polymer is dissolved in a mixture of 10 mL of toluene and 10 mL of pyridine. After adding 5 mL of deionized water and 50 mL of tetrahydrofuran, the solution is titrated with a standard solution of ethanolic potassium hydroxide of known concentration. A blind value is determined using the same procedure but without the polymer.

[0030] Here and throughout this specification, the hydroxyl number is determined according to DIN EN ISO 4629-2 unless otherwise stated.

[0031] Here and throughout this specification, viscosity numbers (VN) are determined according to DIN 53728-3:1985-1 at 25°C using a solution of the respective polymer in a 50:50 w / w mixture of phenol and 1,2-dichlorobenzene.

[0032] Here and throughout this specification, glass transition temperatures (Tg) are determined by dynamic differential scanning calorimetry (DSC) according to DIN EN ISO 11357-1:2017-02, unless otherwise stated.

[0033] Herein and throughout this specification, the terms "melting temperature (Tm)" and "melting point" are used interchangeably. Tm is determined by dynamic differential scanning calorimetry (DSC) in accordance with DIN EN ISO 11357-3:2018-07, unless otherwise specified.

[0034] In the context of the present invention, the characteristic "biodegradable" is fulfilled for a substance or mixture of substances if said substance or mixture of substances has a biodegradability percentage of at least 90% according to DIN EN 13432.

[0035] Biodegradability generally results in a polymer blend that decomposes within a suitable and detectable time frame. Degradation can occur enzymatically, hydrolytically, oxidatively, and / or through the action of electromagnetic radiation, e.g., UV radiation, and is generally primarily carried out by the action of microorganisms such as bacteria, yeast, fungi, and algae. Biodegradability can be quantified, for example, by mixing the polymer blend with compost and storing it for a specific period of time. For example, according to DIN EN 13432, CO2-free air is allowed to flow through matured compost during composting, and the compost is subjected to a specified temperature program. Here, biodegradability is defined as the percentage degree of biodegradability via the ratio of the net CO2 release by the sample (after subtraction of the CO2 release by the compost without the sample) to the maximum CO2 release by the sample (calculated from the carbon content of the sample). Biodegradable polymer blends typically exhibit substantial degradation phenomena, such as fungal growth and the formation of cracks and holes, after just a few days of composting.

[0036] Other methods for determining biodegradability are described, for example, in ASTM D 5338 and ASTM D 6400-4.

[0037] Here, and throughout this specification, the terms "total weight of biodegradable polymer blend," "total weight of polymer blend," and "total weight of blend" are used interchangeably and refer to the total weight of the polymer blend in anhydrous form, unless otherwise specified.

[0038] Here, and throughout this specification, the term "total weight of polyester a), polymer b), and polycaprolactone c)" should be understood as the sum of the total weight of polyester a), the total weight of polymer b), and the total weight of polycaprolactone c).

[0039] Polyester a) The biodegradable polymer blend according to the invention comprises 10 to 80% by weight, preferably 15 to 50% by weight, in particular 20 to 40% by weight, of at least one biodegradable polyester a) selected from the group consisting of aliphatic-aromatic polyesters different from polymers b) and c), aliphatic polyesters, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c).

[0040] The term polyester a) also includes polyesteramides, polyetheresters, polyesterurethanes, and polyestercarbonates, including aliphatic and semi-aromatic polyesteramides, aliphatic and semi-aromatic polyetheresters, aliphatic and semi-aromatic polyesterurethanes, and aliphatic and semi-aromatic aliphatic polyestercarbonates. Here and throughout this specification, the term polyester a) is distinct from polymers b) and c) as defined herein.

[0041] 0.5~70cm 3 / 10 min, preferably 1-65 cm 3 / 10 minutes, preferably 1 to 60 cm 3 Polyesters having a melt volume rate (MVR) according to EN ISO 1133 (190° C., 2.16 kg weight) of 0.1 / 10 min are particularly suitable as polyesters a).

[0042] Preferably, the polymer blend of the present invention comprises at least one polyester a) having a glass transition temperature Tg or melting temperature Tm in the range of 45 to 160° C., in particular in the range of 50 to 150° C., and in particular in the range of 60 to 140° C. If the polymer has a melting point, i.e. is semi-crystalline or crystalline, the polymer preferably has a melting temperature or crystallization temperature in the range of 45 to 160° C., in particular in the range of 50 to 150° C., and in particular in the range of 60 to 140° C. If the polymer is amorphous, the polymer preferably has a Tg in the range of 45 to 160° C., in particular in the range of 50 to 150° C., and in particular in the range of 60 to 140° C.

[0043] The polyester a) typically has a number-average molecular weight (Mn) in the range of 1,000 to 100,000 g / mol, particularly in the range of 1,000 to 75,000 g / mol, and preferably in the range of 1,500 to 70,000 g / mol. The weight-average molecular weight (Mw) of the polyester a) is typically in the range of 3,000 to 300,000 g / mol, and preferably in the range of 3,000 to 200,000 g / mol. The Mw / Mn ratio is typically in the range of 1 to 6, and preferably in the range of 2 to 5. The viscosity number (VN) is 50 to 450 g / ml, and preferably 80 to 250 g / ml. The melting point, determined by DSC, is in the range of 85 to 150°C, and preferably in the range of 95 to 140°C.

[0044] According to the invention, the biodegradable polyester a) is selected from the group consisting of aliphatic-aromatic polyesters different from the polymers b) and c), aliphatic polyesters, and mixtures thereof.

[0045] Here and throughout the specification, aliphatic polyesters are understood to mean polyesters based on aliphatic dicarboxylic acids and aliphatic dihydroxyl compounds, as well as polyesters based on mixtures of aliphatic dicarboxylic acids with aliphatic dicarboxylic acids and aliphatic dihydroxyl compounds. Instead of dicarboxylic acids, their respective ester-forming derivatives or mixtures with dicarboxylic acids can also be used to prepare aliphatic-aliphatic polyesters.

[0046] Aliphatic dicarboxylic acids and their ester-forming derivatives are generally considered to have 2 to 18 carbon atoms, preferably 4 to 10 carbon atoms. They may be linear or branched. However, in principle, it is also possible to use dicarboxylic acids having a larger number of carbon atoms, for example, up to 50 carbon atoms.

[0047] Examples of aliphatic dicarboxylic acids and their ester-forming derivatives include, but are not limited to, oxalic acid, malonic acid, succinic acid, 2-methylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, α-ketoglutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, brassylic acid, fumaric acid, 2,2-dimethylglutaric acid, suberic acid, diglycolic acid, oxaloacetic acid, glutamic acid, aspartic acid, itaconic acid, and maleic acid, their anhydrides, and their C1-C4 alkyl esters. These dicarboxylic acids or their ester-forming derivatives may be used individually or as a mixture of two or more thereof.

[0048] It is preferable to use succinic acid, adipic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, brassylic acid, or their respective ester-forming derivatives, or mixtures thereof. It is particularly preferable to use succinic acid, adipic acid, or sebacic acid, or their respective ester-forming derivatives, or mixtures thereof. Succinic acid, azelaic acid, sebacic acid, and brassylic acid have the additional advantage of being obtainable from renewable raw materials.

[0049] Preferred examples of suitable aliphatic polyesters include, but are not limited to, aliphatic polyesters in which the aliphatic dicarboxylic acid is selected from succinic acid, adipic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, brassylic acid, and mixtures thereof, with succinic acid, adipic acid, and sebacic acid, and mixtures thereof, being particularly preferred.

[0050] Examples of aliphatic diols suitable for preparing aliphatic polyesters include branched or linear alkanediols having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, or cycloalkanediols having 5 to 10 carbon atoms. Examples of suitable alkanediols are ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, and 2,2,4-trimethyl-1,6-hexanediol, in particular ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propanediol (neopentyl glycol). Examples of cycloalkanediols are cyclopentanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Aliphatic polyesters can also contain mixtures of different condensed alkanediols. 1,4-butanediol and propane-1,3-diol, more specifically 1,4-butanediol, are particularly preferred, especially in combination with one or two aliphatic dicarboxylic acids selected from succinic acid, adipic acid, and sebacic acid. Propane-1,3-diol has the advantage of being available as a renewable raw material. 1,4-butanediol can also be obtained from renewable raw materials. PCT / EP2008 / 006714 discloses a biotechnological method for preparing 1,4-butanediol starting from different carbohydrates using microorganisms of the class consisting of the Pasteurellaceae family.

[0051] Examples of preferred aliphatic polyesters are poly(butylene succinate-co-adipate), poly(butylene succinate), poly(butylene sebacate), poly(butylene succinate-co-sebacate), and mixtures thereof. Even more preferred examples of aliphatic polyesters are poly(butylene succinate-co-adipate), poly(butylene succinate), poly(butylene succinate-co-sebacate), and mixtures thereof. Suitable aliphatic polyesters of this type are commercially available under the following product brand BioPBS™ by PTT-MCC.

[0052] Preferred aliphatic polyesters of component a) often have number average molecular weights Mn, determined from GPC, in the range of 1000 to 100000 g / mol, in particular in the range of 1000 to 75000 g / mol, especially in the range of 1500 to 65000 g / mol.

[0053] Preferred aliphatic polyesters of component a) often have a melting point, determined by DSC, in the range of 50 to 130°C, especially in the range of 55 to 125°C, and especially in the range of 65 to 120°C.

[0054] In particular, the aliphatic polyesters of component a) include partially or highly crystalline solid aliphatic copolyesters.

[0055] The aliphatic polyester, especially the aliphatic copolyester, of component a) is preferably 2.5 to 30 cm 3 / 10 minutes range of melt volume rate (MVR) according to EN ISO 1133 (190 °C, 2.16 kg weight).

[0056] In preferred polymer blends of the present invention, component a) comprises an aliphatic-aromatic polyester.

[0057] Aliphatic-aromatic polyesters are also called semi-aromatic polyesters, i.e., polyesters based on aromatic dicarboxylic acids and aliphatic dihydroxyl compounds, as well as polyesters based on mixtures of aromatic dicarboxylic acids with aliphatic dicarboxylic acids and aliphatic dihydroxyl compounds. Aliphatic-aromatic polyesters are preferably polyesters based on mixtures of aliphatic dicarboxylic acids with aromatic dicarboxylic acids and aliphatic dihydroxyl compounds. These polymers can be present individually or in mixtures.

[0058] Preferably, "aliphatic-aromatic polyester" should also be understood to mean polyester derivatives such as polyetheresters, polyesteramides, or polyetheresteramides and polyesterurethanes, as described, for example, in WO 2012 / 2013506. Suitable aliphatic-aromatic polyesters include linear, non-chain-extended polyesters, as described, for example, in WO 92 / 09654. Chain-extended and / or branched aliphatic-aromatic polyesters are preferred. The latter are known from WO 96 / 15173, WO 96 / 15174, WO 96 / 15175, WO 96 / 15176, WO 96 / 21689, WO 96 / 21690, WO 96 / 21691, WO 96 / 21692, WO 96 / 25446, WO 96 / 25448, and WO 98 / 12242, to which explicit reference is made. Mixtures of different aliphatic-aromatic polyesters are also contemplated. Interesting recent developments are based on renewable raw materials and are described, inter alia, in WO 2006 / 097353, WO 2006 / 097354, and WO 2010 / 034710.

[0059] Preferred aliphatic-aromatic polyesters are characterized by number average molecular weights Mn, determined by GPC, in the range of 1000 to 100000 g / mol, in particular in the range of 1000 to 75000 g / mol, preferably in the range of 1500 to 50000 g / mol.

[0060] A preferred aliphatic-aromatic polyester contains, as essential components: i. 20 to 95 mol %, in particular 20 to 90 mol %, in particular 20 to 85 mol % of at least one aliphatic dicarboxylic acid or its ester-forming derivative, or a mixture thereof, as component i, based on the total molar percentage of components i and ii; ii. 5 to 80 mol %, particularly 10 to 80 mol %, and particularly 15 to 80 mol % of at least one aromatic dicarboxylic acid or an ester-forming derivative thereof, or a mixture thereof, as component ii, based on the total molar percentage of components i and ii. and an acid component formed from; C2~C 12 - at least one diol as component iii selected from alkanediols; Optionally, a component iv. selected from one or more chain extenders as component iv.a and / or one or more crosslinkers as component iv.b, Examples of polyesters include:

[0061] The aliphatic dicarboxylic acid and its ester-forming derivative (component i) are as defined above in the context of the aliphatic polyester. Examples thereof are also as set forth above. The aliphatic dicarboxylic acid and its ester-forming derivative can be used individually or in mixtures.

[0062] Preferred aliphatic dicarboxylic acids include, but are not limited to, succinic acid, adipic acid, sebacic acid, azelaic acid, 1,12-dodecanedioic acid, brassylic acid, or their respective ester-forming derivatives, or mixtures thereof. It is particularly preferred to use adipic acid, sebacic acid, azelaic acid, or their respective ester-forming derivatives, or mixtures thereof. As mentioned above, succinic acid, sebacic acid, azelaic acid, and brassylic acid have the additional advantage of being obtainable from renewable raw materials.

[0063] The aliphatic dicarboxylic acid (component i) is present in an amount of, in particular, 20 to 90 mol %, in particular 20 to 85 mol %, or 25 to 85 mol %, or 30 to 85 mol %, based on the total molar percentage of the acid components i and ii. Sebacic acid, azelaic acid, and brassylic acid can be obtained from renewable raw materials, in particular from castor oil.

[0064] The aromatic dicarboxylic acid or its ester-forming derivative (ii) may be used individually or as a mixture of two or more thereof. It is particularly preferred to use terephthalic acid or furan-2,5-dicarboxylic acid and its ester-forming derivative. Di-C1-C6-alkyl esters, such as dimethyl ester, diethyl ester, di-n-propyl ester, diisopropyl ester, di-n-butyl ester, diisobutyl ester, di-tert-butyl ester, di-n-pentyl ester, di-isopentyl ester, or di-n-hexyl ester, may be mentioned as particular examples of ester-forming derivatives. Anhydrides of dicarboxylic acids may also be used. A particularly suitable ester-forming derivative of terephthalic acid is dimethyl terephthalate.

[0065] In one group of embodiments, the aromatic dicarboxylic acid is terephthalic acid or its ester-forming derivative. Preferably, terephthalic acid (component ii) or its ester-forming derivative is present in an amount of 30 to 75 mol%, more preferably 35 to 65 mol%, and especially 40 to 60 mol%, based on the total molar percentage of acid components i and ii, respectively. In this case, the total amount of aliphatic dicarboxylic acids or their ester-forming derivatives is preferably in the range of 25 to 70 mol%, more preferably 35 to 65 mol%, and especially 40 to 60 mol%, based on the total molar percentage of acid components i and ii.

[0066] In another group of embodiments, the aromatic dicarboxylic acid is furan-2,5-dicarboxylic acid or its ester-forming derivative. Preferably, furan-2,5-dicarboxylic acid (component ii) or its ester-forming derivative is present in an amount of 40 to 80 mol%, more preferably 50 to 80 mol%, and especially 60 to 80 mol%, based on the total molar percentage of acid components i and ii, respectively. In this case, the total amount of aliphatic dicarboxylic acids or their ester-forming derivatives is preferably in the range of 20 to 60 mol%, more preferably in the range of 20 to 50 mol%, and especially in the range of 20 to 40 mol%, based on the total molar percentage of acid components i and ii.

[0067] Generally, the diol (component iii) is selected from branched or linear alkanediols having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, or cycloalkanediols having 5 to 10 carbon atoms. Examples of suitable alkanediols are ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,4-diol, pentane-1,5-diol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-ethyl-2-butylpropane-1,3-diol, 2-ethyl-2-isobutylpropane-1,3-diol, 2,2,4-trimethylhexane-1,6-diol, in particular ethylene glycol, propane-1,3-diol, butane-1,4-diol, and 2,2-dimethylpropane-1,3-diol (neopentyl glycol). Examples of suitable cycloalkanediols are cyclopentanediol, cyclohexane-1,4-diol, cyclohexane-1,2-dimethanol, cyclohexane-1,3-dimethanol, cyclohexane-1,4-dimethanol, and 2,2,4,4-tetramethylcyclobutane-1,3-diol. The aliphatic-aromatic polyester may also contain a combination of different alkanediols or cycloalkanediols. Butane-1,4-diol and propane-1,3-diol, especially butane-1,4-diol, are particularly preferred. Propane-1,3-diol has the advantage of being obtainable as a renewable raw material. 1,4-butanediol can also be obtained from renewable raw materials. PCT / EP2008 / 006714 discloses a biotechnological method for preparing 1,4-butanediol starting from different carbohydrates using microorganisms from the family Pasteurellaceae.

[0068] As a rule, the diol (component iii) is prepared at the beginning of the polymerization in a ratio of diol to diacid of 1.0 to 2.5:1, preferably 1.3 to 2.2:1, relative to the acids (components i and ii). Removal of excess diol during the polymerization results in the establishment of an approximately equimolar ratio at the end of the polymerization. Approximately equimolar is understood to mean a diol / diacid ratio of 0.98 to 1.02:1.

[0069] In particular, suitable aliphatic-aromatic polyesters are i. 20 to 95 mol %, particularly 20 to 90 mol %, particularly 20 to 85 mol %, based on the total molar percentage of components i and ii, of one or more aliphatic dicarboxylic acid ester-forming derivatives or aliphatic dicarboxylic acids selected from the group consisting of succinic acid, adipic acid, sebacic acid, azelaic acid, brassylic acid, and mixtures thereof; ii. 5 to 80 mol %, particularly 10 to 80 mol %, particularly 15 to 80 mol %, based on the total molar percentage of components i and ii, of one or more aromatic dicarboxylic acid ester-forming derivatives or aromatic dicarboxylic acids selected from the group consisting of terephthalic acid and furan-2,5-dicarboxylic acid, and mixtures thereof; iii. 98 to 102 mol % of a C2 to C8 alkylene diol or a C2 to C6 oxyalkylene diol, based on components i and ii; iv. 0.00 to 2 wt. %, particularly 0.01 to 2 wt. %, particularly 0.2 to 1.5 wt. %, particularly 0.35 to 1 wt. %, based on the total weight of components i to iii, of a chain extender (component iv.a) and / or crosslinker (component iv.b) selected from the group consisting of difunctional or polyfunctional isocyanates, isocyanurates, oxazolines, epoxides, carboxylic acid anhydrides, alcohols having at least three functional groups, and carboxylic acids having at least three functional groups; Includes.

[0070] For paper coating, aliphatic-aromatic polyesters with a high proportion of aliphatic dicarboxylic acids, based on the total molar percentage of aliphatic and aromatic dicarboxylic acids, are particularly suitable, typically 20-95 mol %, especially 20-90 mol %, and especially 20-85 mol %. The higher the proportion of aliphatic dicarboxylic acids in the aliphatic-aromatic polyester, the thinner the layers can be achieved. Films of these polyesters are less prone to resonance melting in coating plants.

[0071] In a preferred group of embodiments, the aliphatic-aromatic polyester is selected from the group consisting of poly(butylene adipate-co-terephthalate), poly(butylene sebacate-co-terephthalate), poly(butylene azelate-co-terephthalate), poly(butylene succinate-co-terephthalate), poly(butylene adipate-co-sebacate-co-terephthalate), poly(butylene adipate-co-azelate-co-terephthalate), poly(butylene adipate-co-succinate-co-terephthalate), poly(butylene sebacate-co-azelate-co-terephthalate), poly(butylene sebacate-co-succinate-co-terephthalate), poly(butylene azelate-co-succinate-co-terephthalate). -terephthalate), poly(butylene adipate-co-furanoate), poly(butylene sebacate-co-furanoate), poly(butylene azelate-co-furanoate), poly(butylene succinate-co-furanoate), poly(butylene adipate-co-sebacate-co-furanoate), poly(butylene adipate-co-azelate-co-furanoate), poly(butylene adipate-co-succinate-co-furanoate), poly(butylene sebacate-co-azelate-co-furanoate), poly(butylene sebacate-co-succinate-co-furanoate), poly(butylene azelate-co-succinate-co-furanoate), and mixtures thereof. The above-mentioned aliphatic-aromatic polyesters have VST / A50 (Vicat softening temperature) values, determined in accordance with DIN EN ISO 306, in the range of 50 to 160°C, in particular in the range of 55 to 150°C.

[0072] In a more preferred group of embodiments, the aliphatic-aromatic polyester is selected from the group consisting of poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene sebacate-co-terephthalate) (PBSeT), poly(butylene azelate-co-terephthalate) (PBAzT), poly(butylene succinate terephthalate) (PBST), poly(butylene adipate-co-sebacate-co-terephthalate) (PBASeT), poly(butylene adipate-co-azelate-co-terephthalate) (PBAzT). BAAzT), poly(butylene adipate-co-furanoate) (PBAF), poly(butylene sebacate-co-furanoate) (PBSeF), poly(butylene azelate-co-furanoate) (PBAzF), poly(butylene succinate-co-furanoate) (PBSF), poly(butylene adipate-co-sebacate-co-furanoate) (PBASeF), poly(butylene adipate-co-azelate-co-furanoate) (PBAAzF), and mixtures thereof.

[0073] In a preferred group of embodiments, the polyester a) is selected from the group consisting of poly(butylene adipate-co-terephthalate), poly(butylene sebacate-co-terephthalate), poly(butylene azelate-co-terephthalate), poly(butylene succinate-co-terephthalate), poly(butylene adipate-co-sebacate-co-terephthalate), poly(butylene adipate-co-azelate-co-terephthalate), poly(butylene adipate-co-succinate-co-terephthalate), poly(butylene sebacate-co-azelate-co-terephthalate), poly(butylene azelate-co-succinate-co-terephthalate), poly(butylene adipate-co-furanoate), poly (butylene sebacate-co-furanoate), poly(butylene azelate-co-furanoate), poly(butylene succinate-co-furanoate), poly(butylene adipate-co-sebacate-co-furanoate), poly(butylene adipate-co-azelate-co-furanoate), poly(butylene adipate-co-succinate-co-furanoate), poly(butylene se The poly(butylene succinate-co-azelate-co-furanoate), poly(butylene sebacate-co-succinate-co-furanoate), poly(butylene azelate-co-succinate-co-furanoate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene succinate-co-sebacate), and mixtures thereof.

[0074] In a particularly preferred group of embodiments, the polyester a) is selected from the group consisting of poly(butylene adipate-co-terephthalate), poly(butylene sebacate-co-terephthalate), poly(butylene azelate-co-terephthalate), poly(butylene adipate-co-sebacate-co-terephthalate), poly(butylene adipate-co-azelate-co-terephthalate), poly(butylene adipate-co-furanoate), poly(butylene sebacate-co-terephthalate), The poly(butylene succinate-co-furanoate), poly(butylene adipate-co-sebacate-co-furanoate), poly(butylene adipate-co-azelate-co-furanoate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene succinate-co-sebacate), and mixtures thereof.

[0075] The amount of aliphatic-aromatic polyester is in particular at least 50% by weight, in particular at least 70% by weight, or at least 80% by weight, or at least 90% by weight, based on the total weight of component a), and may be as high as 100% by weight.

[0076] The synthesis of the polyesters a) described is preferably carried out in a two-step reaction cascade by the methods described in WO 92 / 09654, WO 96 / 15173 or preferably in PCT / EP2009 / 054114 and PCT / EP2009 / 054116.

[0077] The two above-mentioned methods make it possible to adjust the desired MVR range simply by selecting process parameters such as residence time, reaction temperature, and amount taken off at the top of the column reactor.

[0078] Adaptation of the MVR to lower values ​​can be achieved by adding component iv) in the concentration ranges stated or, in the case of polymer mixtures, by suitable compatibilizers.

[0079] Optionally, the polyester may contain 0 to 2 wt. %, particularly 0.2 to 1.5 wt. %, and especially 0.35 to 1 wt. %, based on the total weight of components i to iii, of a chain extender (iv.a) and / or crosslinker (iv.b) selected from the group consisting of di- or polyfunctional isocyanates, isocyanurates, oxazolines, carboxylic acid anhydrides such as maleic anhydride, epoxides, especially epoxide-containing poly(meth)acrylates, alcohols having at least three functional groups, and carboxylic acids having at least three functional groups. Suitable chain extenders (iv.a) are especially difunctional isocyanates, isocyanurates, oxazolines, carboxylic acid anhydrides, or epoxides.

[0080] Chain extenders and alcohol or carboxylic acid derivatives with at least three functional groups can also be considered crosslinkers. Particularly preferred compounds have three to six functional groups. Examples include tartaric acid, citric acid, malic acid; trimethylolpropane, trimethylolethane, pentaerythritol; polyether triols and glycerol, trimesic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride. Polyols such as trimethylolpropane, pentaerythritol, and especially glycerol are preferred.

[0081] Examples of chain extenders are described in more detail below.

[0082] The epoxides are particularly selected from homopolymers and copolymers containing epoxide groups. The units containing epoxide groups are preferably formed from glycidyl esters or glycidyl ethers having ethylenically unsaturated double bonds, especially (meth)acrylates. Suitable comonomers are styrene, acrylates, and / or methacrylates. Copolymers with a proportion of glycidyl (meth)acrylate of more than 20% by weight, particularly preferably more than 30% by weight, and particularly preferably more than 50% by weight, based on the total amount of monomers forming the epoxide polymer, have proven advantageous. The epoxide equivalent weight (EEW) of these polymers is preferably 150 to 3000 g / eq, particularly preferably 200 to 500 g / eq. The average molecular weight (weight average) Mw of the polymer is preferably 2000 to 25000 g / mol, especially 3000 to 8000 g / mol. The average molecular weight (number average) Mn of the polymer is preferably 400 to 6000 g / mol, in particular 1000 to 4000 g / mol. The polydispersity (Mw / Mn) is generally 1.5 to 5. Copolymers of the above-mentioned type containing epoxide groups are sold, for example, by BASF under the brand name Joncryl® ADR. Particularly suitable chain extenders are Joncryl® ADR 4468 or Joncryl® ADR 4400.

[0083] In principle, it is advantageous to add the crosslinking compound having at least three functional groups relatively early in the polymerization of the polyester a).

[0084] Suitable difunctional chain extenders are the following compounds: The aromatic diisocyanate (component iv.a) is understood to mean, in particular, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthylene 1,5-diisocyanate, or xylylene diisocyanate. Among these, 2,2'-, 2,4'-, and 4,4'-diphenylmethane diisocyanate are particularly preferred. The latter diisocyanates are generally used as mixtures. The diisocyanate may also contain small amounts, for example, up to 5% by weight, of urethione groups, based on the total weight of the diisocyanate, for example, to block the isocyanate groups.

[0085] In the context of the present invention, aliphatic diisocyanates are understood to mean, in particular, linear or branched alkylene diisocyanates or cycloalkylene diisocyanates having 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, such as hexamethylene 1,6-diisocyanate, isophorone diisocyanate, or methylenebis(4-isocyanatocyclohexane). Particularly preferred aliphatic diisocyanates are isophorone diisocyanate and especially hexamethylene 1,6-diisocyanate.

[0086] Preferred isocyanurates include aliphatic isocyanurates derived from alkylene diisocyanates or cycloalkylene diisocyanates having 2 to 20 carbon atoms, preferably 3 to 12 carbon atoms, such as isophorone diisocyanate or methylenebis(4-isocyanatocyclohexane). The alkylene diisocyanates may be linear or branched. Isocyanurates based on n-hexamethylene diisocyanate, such as cyclic trimers, pentamers, or higher oligomers of hexamethylene 1,6-diisocyanate, are particularly preferred.

[0087] Polymer b) The biodegradable polymer blend according to the present invention comprises 18 to 88% by weight, in particular 35 to 70% by weight, in particular 40 to 70% by weight, of at least one polymer b) selected from the group consisting of polyhydroxyalkanoates, polylactides, polyglycolic acid, and mixtures thereof, based on the total weight of polyester a), polymer b) and polycaprolactone c).

[0088] Polyhydroxyalkanoates are also called polyhydroxy fatty acids, and in the context of the present invention, they are understood to mean those containing monomers with a chain length in the polymer backbone of at least 3 carbon atoms.Therefore, polylactic acid and polyhydroxyacetic acid (also called polyglycolic acid) are not polyhydroxyalkanoates in the context of the present invention.In the context of the present invention, polycaprolactone (PCL) is also not understood as polyhydroxyalkanoates.

[0089] According to the present invention, a repeating monomer unit of formula (1): [-O-CHR-(CH2) m -CO-](1) (wherein R is hydrogen or a linear or branched alkyl group having 1 to 20, preferably 1 to 16, carbon atoms, preferably 1 to 6 carbon atoms, and m is a number of 1 to 18, preferably 1, 2, 3, 4, 5, and 6). It is preferred to use at least one polyhydroxyalkanoate containing and / or a homopolymer of 2-hydroxybutyric acid.

[0090] Polyhydroxy fatty acids include homopolymers, ie, polyhydroxy fatty acids composed of the same hydroxy fatty acid monomers, and also copolymers, ie, polyhydroxy fatty acids composed of different hydroxy fatty acid monomers.

[0091] The polyhydroxy fatty acids may be used individually or in the form of any mixture.

[0092] Polyhydroxy fatty acids in the context of the present invention often have a molecular weight Mw of 5,000 to 1,000,000 g / mol, in particular 30,000 to 1,000,000 g / mol, in particular 70,000 to 1,000,000 g / mol, preferably 100,000 to 1,000,000 g / mol or 200,000 to 600,000 g / mol, and / or a melting point in the range of 100 to 190°C.

[0093] The polyhydroxy fatty acid is preferably 1 to 50 cm 3 / 10 minutes, preferably 1.5 to 40 cm 3 / 10 minutes, preferably 2-30cm 3 / 10 minutes according to EN ISO 1133 (165 °C, 5 kg weight).

[0094] In one embodiment of the present invention, the at least one polyhydroxyalkanoate is poly(3-hydroxypropionate) (P3HP); Polyhydroxybutyrate (PHB); Polyhydroxyvalerate (PHV); Polyhydroxyhexanoate (PHHx); Polyhydroxyoctanoate (PHO); Polyhydroxyoctadecanoate (PHOd); copolyesters of hydroxybutyric acid and at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyvaleric acid, hydroxyhexanoic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid; a copolyester of hydroxyvaleric acid and at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyhexanoic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid; and Copolyesters of hydroxyhexanoic acid and at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid. is selected from the group consisting of:

[0095] Suitable polyhydroxybutyrates (PHB) may be selected from the group consisting of poly(3-hydroxybutyrate) (P3HB), poly(4-hydroxybutyrate) (P4HB), and copolymers of at least three hydroxybutyrates selected from the group consisting of 3-hydroxybutyrate and 4-hydroxybutyrate. Copolymers of 3-hydroxybutyrate and 4-hydroxybutyrate are more suitable. These copolymers are characterized by the following abbreviation: [P(3HB-co-4HB)] (where 3HB is 3-hydroxybutyrate and 4HB is 4-hydroxybutyrate).

[0096] Poly(3-hydroxybutyrate) is commercially available, for example, from Tianan under the trade name Enmat®. Poly-3-hydroxybutyrate-co-4-hydroxybutyrate has been developed, among others, by Metabolix. It is currently being commercialized by CJ CheilJedang.

[0097] Suitable polyhydroxyvalerates (PHVs) are: homopolymer of 3-hydroxyvaleric acid [= poly(3-hydroxyvalerate) (P3HV)]; homopolymer of 4-hydroxyvaleric acid [= poly(4-hydroxyvalerate) (P4HV)]; homopolymer of 5-hydroxyvaleric acid [= poly(5-hydroxyvalerate) (P5HV)]; Homopolymer of 3-hydroxymethylvaleric acid [= poly(3-hydroxymethylvalerate) (P3MHV)]; and A copolymer of at least three hydroxyvaleric acids selected from the group consisting of 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, and 3-hydroxymethylvaleric acid. may be selected from the group consisting of:

[0098] Suitable polyhydroxyhexanoates (PHHx) may be selected from the group consisting of poly(3-hydroxyhexanoate) (P3HHx), poly(4-hydroxyhexanoate) (P4HHx), poly(6-hydroxyhexanoate) (P6HHx), and copolymers of at least 3-hydroxyhexanoic acid selected from the group consisting of 3-hydroxyhexanoic acid, 4-hydroxyhexanoic acid, and 6-hydroxyhexanoic acid.

[0099] Suitable polyhydroxyoctanoates (PHO) may be selected from the group consisting of poly(3-hydroxyoctanoate) (P3HO), poly(4-hydroxyoctanoate) (P4HO), poly(6-hydroxyoctanoate) (P6HO), and copolymers of at least 3-hydroxyoctanoic acid selected from the group consisting of 3-hydroxyoctanoic acid, 4-hydroxyoctanoic acid, and 6-hydroxyoctanoic acid.

[0100] Suitable copolyesters of hydroxybutyric acid and at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyvaleric acid, hydroxyhexanoic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid are copolyester of 4-hydroxybutyric acid and 3-hydroxyvaleric acid [P(4HB-co-3HV)]; copolyester of 3-hydroxybutyric acid and 3-hydroxyvaleric acid [P(3HB-co-3HV)]; copolyesters of 4-hydroxybutyric acid and 3-hydroxyhexanoic acid [P(4HB-co-3HHx)]; copolyesters of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid [P(3HB-co-3HHx)]; copolyester of 4-hydroxybutyric acid and 3-hydroxyoctanoic acid [P(4HB-co-3HO)]; Copolyester of 3-hydroxybutyric acid and 3-hydroxyoctanoic acid [P(3HB-co-3HO)]; and Copolyesters of 4-hydroxybutyric acid and 3-hydroxyoctadecanoic acid [P(4HB-co-3HOd)] and 3-hydroxybutyric acid and 3-hydroxyoctadecanoic acid [P(3HB-co-3HOd)] may be selected from the group consisting of:

[0101] It is preferred to use poly-3-hydroxybutyrate-co-3-hydroxyhexanoate having a 3-hydroxyhexanoate content of 1 to 20, preferably 3 to 15 mol %, based on the total amount of polyhydroxy fatty acid. Such poly-3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] is known from Kaneka Corporation and is commercially available under the trade names Aonilex® X131A and Aonilex® X151A.

[0102] Suitable copolyesters of hydroxyvaleric acid are preferably copolyesters of 4-hydroxyvaleric acid and / or 3-hydroxyvaleric acid with at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyhexanoic acid, hydroxyoctanoic acid, in particular 3-hydroxyoctanoic acid, and hydroxyoctadecanoic acid.

[0103] Suitable copolyesters of hydroxyhexanoic acid are preferably copolyesters of 3-hydroxyhexanoic acid with at least one monomer selected from the group consisting of 3-hydroxypropionic acid and hydroxyoctanoic acid, preferably 3-hydroxyoctanoic acid and hydroxyoctadecanoic acid.

[0104] In one embodiment of the present invention, the at least one polyhydroxyalkanoate is selected from the group consisting of poly(3-hydroxypropionate) (P3HP); copolymers of at least three hydroxybutyric acids selected from the group consisting of 3-hydroxybutyric acid and 4-hydroxybutyric acid; copolymers of 3-hydroxybutyric acid and 4-hydroxybutyric acid; poly(3-hydroxyvalerate) (P3HV); poly(4-hydroxyvalerate) (P4HV); poly(5-hydroxyvalerate) (P5HV); poly(3-hydroxy copolymers of at least three hydroxyvaleric acids selected from the group consisting of 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, and 3-hydroxymethylvaleric acid; poly(3-hydroxyhexanoate) (P3HHx); poly(4-hydroxyhexanoate) (P4HHx); poly(6-hydroxyhexanoate) (P6HHx); copolymers consisting of 3-hydroxyhexanoic acid, 4-hydroxyhexanoic acid, and 6-hydroxyhexanoic acid copolymers of at least three hydroxyoctanoic acids selected from the group consisting of 3-hydroxyoctanoic acid, 4-hydroxyoctanoic acid, and 6-hydroxyoctanoic acid; poly(3-hydroxyoctanoate) (P3HO); poly(4-hydroxyoctanoate) (P4HO); poly(6-hydroxyoctanoate) (P6HO); copolymers of at least three hydroxyoctanoic acids selected from the group consisting of 3-hydroxyoctanoic acid, 4-hydroxyoctanoic acid, and 6-hydroxyoctanoic acid; copolyesters of 3-hydroxybutyric acid and at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyvaleric acid, hydroxyhexanoic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid;Copolyesters of 4-hydroxybutyric acid and 3-hydroxyoctanoic acid [P(4HB-co-3HO)], 3-hydroxybutyric acid and 3-hydroxyoctanoic acid [P(3HB-co-3HO)], 4-hydroxybutyric acid and 3-hydroxyoctadecanoic acid [P(4HB-co-3HOd)], 3-hydroxybutyric acid and 3-hydroxyoctadecanoic acid [P(3HB-co-3HOd)]; copolyesters of hydroxyvaleric acid, in particular 3-hydroxyvaleric acid or 4-hydroxyvaleric acid, with at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyhexanoic acid, hydroxyoctanoic acid, and hydroxyoctadecanoic acid; copolyesters of 3-hydroxyhexanoic acid with at least one monomer selected from the group consisting of 3-hydroxypropionic acid, hydroxyoctanoic acid, preferably 3-hydroxyoctanoic acid and hydroxyoctadecanoic acid;

[0105] Suitable polyhydroxyalkanoates as a rule have molecular weights Mw of 100,000 to 1,000,000 g / mol, preferably 300,000 to 600,000 g / mol, determined from GPC in HFIP as solvent against narrowly distributed PMMA standards.

[0106] Polylactide, also known as polylactic acid, has the skeletal formula (C3H4O2) n or [-C(CH3)HC(=O)O-] n and is formally obtained by the condensation of lactic acid, C(CH3)(OH)HCOOH, followed by dehydration. It can also be prepared by the ring-opening polymerization of the cyclic dimer of the basic repeating unit, lactide [-C(CH3)HC(=O)O-]2. Suitable PLA typically contains at least 90% by weight, and preferably at least 95% by weight or more, of lactic acid repeating units, based on the total weight of the PLA.

[0107] The polylactide can be crystalline, semi-crystalline, or amorphous. In particular, suitable polylactides have a melting or softening point, as determined by DSC, of ​​less than 240°C, particularly less than 230°C, and especially less than 220°C. Generally, the melting point of crystalline or semi-crystalline polylactides is at least 120°C.

[0108] The polylactide preferably has a melt volume rate (MFR) according to EN ISO 1133 (190°C, 2.16 kg weight) in the range of 5 to 60 g / 10 min, preferably 10 to 55 g / 10 min, more preferably 15 to 50 g / 10 min.

[0109] Preferred polylactides are commercially available from NatureWorks, for example, under the trade names Ingeo™ 6201D, Ingeo™ 6202D, Ingeo™ 6251D, Ingeo™ 3051D, Ingeo™ 4043D, especially Ingeo™ 3251D; from Total Corbion, under the trade names Luminy LX975, LX930, LX175; LX575, L130, LX530, especially Luminy L105; and from Hisun, under the trade names Revode 110, 190, especially Revode 290.

[0110] In a preferred group of embodiments, the polymer b) is selected from the group consisting of polylactides.

[0111] Biodegradable polymer blends containing at least one aliphatic-aromatic polyester as defined above and polylactic acid are suitable for coating paper. Polymer blends typically have a multiphase structure, i.e., different polymer components of the blend are present in different spatial regions within the blend. For example, the blend may have a continuous phase and a discontinuous phase distributed within the continuous phase. For example, polymer b), preferably polylactic acid, may form the continuous phase of the polymer blend, with the other components forming dispersed or co-continuous phases with the polylactic acid continuous phase. This may be the case for polymer blends containing more than 50% by weight of polylactic acid. Compared to pure PLA, these blends are notable for a reduction in the neck-in of the molten web upon exiting a flat die, with the neck-in reduced by at least 10%, preferably 20-80%, and more preferably 30-60%. Compared to pure polybutylene adipate terephthalate (PBAT), the molten web is significantly more stable, reaching thicknesses of 30 g / m². 2 less than 20 g / m 2 less than 17 g / m 2 It has better stretching properties up to less than 100 m / min. Effective adhesion to cellulosic substrates (paper, cardboard) is maintained depending on the cooling conditions for high web speeds above 100 m / min.

[0112] Polymer blends may also have a co-continuous phase configuration, that is, different polymer components of the blend are present in different interpenetrating spatial regions within the blend.

[0113] Polyglycolic acid, also known as polyglycolide, is a biodegradable thermoplastic polymer and the simplest linear aliphatic polyester. It can be prepared starting from glycolic acid by polycondensation or from glycolide by ring-opening polymerization.

[0114] Polyglycolic acid includes glycolic acid homopolymers consisting only of glycolic acid repeating units represented by the formula -(O-CH-CO)- (including ring-opening polymerization products of glycolide, a dicyclic ester of glycolic acid), as well as glycolic acid copolymers containing at least 70% by weight of the above-mentioned glycolic acid repeating units.

[0115] Examples of comonomers for providing polyglycolic acid copolymers with glycolic acid monomers such as glycolide include, but are not limited to, ethylene oxalate (i.e., 1,4-dioxane-2,3-dione); lactide; cyclic monomers including lactones such as β-propiolactone, β-butyrolactone, pivalolactone, γ-butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, and ε-caprolactone; carbonates such as trimethylene carbonate; ethers such as 1,3-dioxane; ether esters such as dioxanone; and amides such as ε-caprolactam; hydroxycarboxylic acids such as lactic acid, 3-hydroxypropanoic acid, 4-hydroxybutanoic acid, and 6-hydroxycaproic acid, and alkyl esters thereof; substantially equimolar mixtures of aliphatic diols such as ethylene glycol and 1,4-butanediol with aliphatic dicarboxylic acids such as succinic acid and adipic acid, and alkyl or aromatic esters thereof; and two or more of these. These monomers may be substituted with the glycolic acid monomers mentioned above, such as glycolide, into polymers that can be used as starting materials to provide polyglycolic acid copolymers.

[0116] The glycolic acid repeating unit should account for at least 70% by weight, preferably at least 90% by weight, of the polyglycolic acid. If the content is too low, the expected strength or gas barrier properties of the polyglycolic acid will be insufficient. As long as this requirement is met, the polyglycolic acid may contain two or more polyglycolic acid (co)polymers in combination.

[0117] The polyglycolic acid preferably has a molecular weight of 3×10 as measured by GPC using hexafluoroisopropanol as a solvent. 4 ~8×10 5 , especially 5×10 4 ~5×10 5 The molecular weight Mw (weight average molecular weight based on polymethyl methacrylate) ranges from 0.01 to 0.01. If the molecular weight is too small, the polyglycolic acid may be expected to exhibit insufficient strength in application. On the other hand, if the molecular weight is too large, melt extrusion, molding, and processing may be difficult.

[0118] The polyglycolic acid is preferably 0.1 to 70 cm 3 / 10 min, preferably 0.8 to 70 cm 3 / 10 minutes, preferably 1 to 60 cm 3 / 10 minutes range of melt volume rate (MVR) according to EN ISO 1133 (240 °C, 2.16 kg weight).

[0119] Polycaprolactone c) The biodegradable polymer blend according to the invention comprises 2 to 72 wt. %, in particular 5 to 50 wt. %, in particular 5 to 30 wt. %, based on the total weight of polyester a), polymer b), and polycaprolactone c), of at least one polycaprolactone c) having a viscosity number (VN) of at least 110 ml / g, determined according to DIN 53728-3:1985-1, the viscosity number being determined at 25°C using a solution of the respective polymer in a 50:50 w / w mixture of phenol and 1,2-dichlorobenzene.

[0120] Polycaprolactone, or more precisely poly-ε-caprolactone, is a class of linear aliphatic polyesters obtained by ring-opening polymerization of ω-caprolactone monomers under the catalysis of metal-organic compounds (such as tetraphenyltin). Generally, polycaprolactone has a melting point of 59-64°C and a glass transition temperature of -60°C. Its structural repeating unit has five nonpolar methylene -CH- and one polar ester group -COO-, i.e., -(COOCHCHCHCHCHCH-).n This structure allows polycaprolactone to have good flexible processability and at the same time good biocompatibility.

[0121] Polycaprolactones are commercially available, for example, from Daicel under the trade name Placel® or from Ingevity under the trade names Capa™ 6400, Capa™ 6500, Capa™ 6800. The viscosity number (VN) of the polycaprolactone c) is in particular at least 150 ml / g, preferably at least 200 ml / g, in particular at least 250 ml / g, determined in accordance with DIN 53728-3:1985-1. In a particular group of embodiments, the VN of the polycaprolactone c) is in the range of 150 to 600 ml / g, preferably 200 to 500 ml / g, in particular 250 to 450 ml / g, determined in accordance with DIN 53728-3:1985-1.

[0122] The number average molecular weight (Mn) of the polycaprolactone c) is generally at least 20,000 g / mol, in particular at least 25,000 g / mol, preferably at least 28,000 g / mol, in particular at least 31,000 g / mol, determined by GPC. In particular, the Mn of the polycaprolactone c) is in the range of 20,000 to 200,000 g / mol, in particular 25,000 to 170,000 g / mol, preferably 28,000 to 150,000 g / mol, in particular 31,000 to 100,000 g / mol, determined by GPC.

[0123] The weight-average molecular weight (Mw) of the polycaprolactones c) is generally at least 50,000 g / mol, in particular at least 70,000 g / mol, preferably at least 80,000 g / mol, in particular at least 115,000 g / mol and for example in the range from 50,000 to 500,000 g / mol, in particular in the range from 70,000 to 350,000 g / mol, preferably in the range from 80,000 to 300,000 g / mol, in particular in the range from 115,000 to 250,000 g / mol, determined by GPC.

[0124] The polydispersity, the ratio of Mw to Mn (Mw / Mn), of the polycaprolactones c) is generally in the range of 1.0 to 6.0, in particular in the range of 1.5 to 5.5, preferably in the range of 2.0 to 5.2, in particular in the range of 2.2 to 5.0.

[0125] The melting point of suitable polycaprolactones is usually in the range of 40 to 70°C, in particular 50 to 65°C, preferably 55 to 65°C, as determined by DSC.

[0126] In particular, 1 to 30 cm 3 / 10 min, preferably 1-20 cm 3 / 10 minutes, especially 1-10cm 3 Polycaprolactones having an MVR according to EN ISO 1133 (160° C., 2.16 kg weight) in the range of 1 / 10 min are suitable.

[0127] The weight ratio of polyester a) to the total of polymer b) and polycaprolactone c) (polyester a:(polymer b+polycaprolactone c)) is in the range of 10:90 to 80:20, preferably 15:85 to 50:50, and more preferably 20:80 to 45:55.

[0128] The weight ratio of polymer b) to polycaprolactone c) is in the range of 9:1 to 1:4, preferably 9:1 to 1:3, more preferably 9:1 to 1:2.

[0129] Based on the total weight of polyester a), polymer b) and polycaprolactone c), the amount of polyester a) is in particular in the range of 15 to 50% by weight, in particular 20 to 40% by weight, the amount of polymer b) is in particular in the range of 35 to 70% by weight, in particular 40 to 70% by weight, and the amount of polycaprolactone c) is in particular in the range of 5 to 50% by weight, in particular 5 to 30% by weight.

[0130] The total weight of polyester a), polymer b) and polycaprolactone c) is at least 50% by weight, in particular at least 60% by weight, in particular at least 65% by weight or at least 70% by weight, based on the total weight of the blend.

[0131] Biodegradable Polymer Blends The biodegradable polymer blends according to the present invention have high biodegradability combined with good film properties.

[0132] Biodegradable polymer blends are generally used in a range of 0.5 to 35 cm according to EN ISO 1133 (190°C, 2.16 kg weight). 3 / 10 min range, preferably 1-30 cm 3 / 10 minutes range, preferably 1.5-25cm 3 It has a melt volume rate (MVR) in the range of 10 / 10 minutes.

[0133] The blends may also be used in applications where the blend is intended for lamination or paper coating, and the temperature is between 5 and 35 cm according to EN ISO 1133 (190°C, 2.16 kg weight). 3 / 10 minute range, especially 10-30cm 3 / 10 min range, especially 14-25cm 3 The melt volume rate (MVR) may range from 1 / 10 min.

[0134] The blends may also be subjected to a temperature of 2 to 35 cm according to EN ISO 1133 (190°C, 2.16 kg weight), especially if the blend is intended for injection molding. 3 / 10 min range, especially 3-30 cm 3 / 10 min range, especially 5-25cm 3 The melt volume rate (MVR) may range from 1 / 10 min.

[0135] The blends may also be used in applications where the blends are intended for thermoforming, particularly in applications where the blends are intended for thermoforming, and the blends are used ... 3 / 10 min range, especially 1-12 cm 3 / 10 minute range, especially 1.5-10cm 3 The melt volume rate (MVR) may range from 1 / 10 min.

[0136] In addition to components a), b), and c), the polymer blend may further comprise additional components other than the polymer components a), b), and c), which will be referred to hereinafter as component d), d1) one or more fillers as component d1); d2) a plasticizer as component d2), and d3) one or more additives other than plasticizers d2) as components d3) other than fillers d1), such as stabilizers, nucleating agents, lubricants and mold release agents, surfactants, waxes, antistatic agents, antifogging agents, dyes, pigments, UV absorbers, UV stabilizers, and mixtures thereof Including, but not limited to:

[0137] The total amount of component d) may be as high as 50% by weight, in particular up to 40% by weight, especially 35% by weight or up to 30% by weight, based on the total weight of the blend.

[0138] In one embodiment, the thermoplastic polymer blend optionally comprises 0 to 38 wt. %, particularly 0 to 30 wt. %, and especially 0 to 29 wt. % of one or more fillers (component (d1)), based on the total weight of the blend.

[0139] Suitable fillers include, but are not limited to, natural or plasticized starch, natural fibers, wood flour and / or inorganic fillers selected from the group consisting of chalk, precipitated calcium carbonate, graphite, gypsum, conductive carbon black, iron oxide, calcium chloride, dolomite, kaolin, silicon dioxide (quartz), sodium carbonate, titanium dioxide, silicates, wollastonite, mica, montmorillonite, talc, glass fibers, and mineral fibers. Starch and amylose may be natural, i.e., not thermoplasticized, or may be thermoplasticized with a plasticizer such as glycerol or sorbitol (see EP 539541, EP 575349, EP 652910). Natural fibers are understood to mean, for example, cellulose fibers, hemp fibers, sisal, kenaf, jute, flax, abaca, coconut fibers, or cordenka fibers. Preferred fibrous fillers include glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, and natural fibers, with E-glass being particularly preferred. These can be used as rovings or, especially, commercially available cut glass. These fibers generally have a diameter of 3 to 30 μm, preferably 6 to 20 μm, and particularly preferably 8 to 15 μm. The fiber length in the compound is generally 20 μm to 1000 μm, preferably 180 to 500 μm, and particularly preferably 200 to 400 μm.

[0140] The biodegradable polymer blend may also contain a plasticizer d2), such as a citrate ester (especially acetyl tributyl citrate), a glyceryl ester such as triacetin, or an ethylene glycol derivative. The plasticizer may be present in an amount of 0 to 10% by weight, in particular 0 to 8.5% by weight, in particular 0 to 5% by weight, based on the total weight of the polymer blend.

[0141] In one embodiment, the biodegradable polymer blend optionally comprises 0 to 2 wt. %, in particular 0 to 1.5 wt. %, in particular 0 to 1 wt. %, based on the total weight of the blend, of at least one component d3), typically selected from the group consisting of stabilizers, nucleating agents, lubricants and release agents, surfactants, waxes, antistatic agents, antifogging agents, dyes, pigments, UV absorbers, UV stabilizers, and mixtures thereof.

[0142] Particularly preferably, the biodegradable polymer blend comprises 0.1 to 30 wt. %, based on the total weight of the polymer blend, of a component d) selected from the group consisting of mineral fillers, plasticizers, nucleating agents, UV stabilizers, carbon black, antiblocking agents, antifogging agents, slip agents (lubricants), chain extenders, starch, cellulose, waxes, and mixtures thereof.

[0143] Suitable nucleating agents include, but are not limited to, polybutylene terephthalate, N,N'-ethylenebisstearylamide, zinc phenylphosphonate, graphite, talc, chalk, precipitated calcium carbonate, kaolin, silica sand, or silicates.

[0144] Suitable release agents include, but are not limited to, stearates (especially calcium stearate, erucamide, behenamide, and stearamide).

[0145] Suitable surfactants include, but are not limited to, polysorbates, palmitates, and laurates.

[0146] Suitable waxes include, but are not limited to, erucamide, stearamide, behenamide, montan wax, beeswax or beeswax esters, vegetable waxes such as candelilla wax or carnauba wax.

[0147] In particular, the polymer blend may optionally comprise: d1) 0 to 38 wt. %, in particular 0 to 30 wt. %, in particular 0 to 29 wt. % of component d1), based on the total weight of the blend; and d2) 0 to 10% by weight, in particular 0 to 8.5% by weight, in particular 0 to 5% by weight of one or more plasticizers d2, based on the total weight of the blend; d3) 0 to 2 wt. %, in particular 0 to 1.5 wt. %, in particular 0 to 1 wt. %, based on the total weight of the blend, of components d3) selected in particular from stabilizers, lubricants and release agents, surfactants, waxes, antistatic agents, antifogging agents, dyes, pigments, UV absorbers, UV stabilizers, and combinations thereof. Includes.

[0148] In one group of embodiments, components d1), d2), and / or d3) are provided to the polymer blend during and / or after the preparation of the polymer blend.

[0149] In another group of embodiments, components d1), d2), and / or d3) are already incorporated into polyester a), and the above-mentioned amounts of components d1) and d2) also apply to this group of embodiments.

[0150] The monolayer or multilayer film of the present invention can further contain additional additives known to those skilled in the art. Examples include additional substances conventionally used in plastics technology, such as stabilizers; nucleating agents; lubricants and release agents such as stearates (especially calcium stearate); plasticizers such as citric acid esters (tributyl acetyl citrate), glycerol esters such as triacetin, or ethylene glycol derivatives; surfactants such as polysorbates, palmitates, or laurates; waxes such as erucamide, stearamide, behenamide, beeswax, beeswax esters, candelilla, carnauba, or montan wax; antistatic agents; UV absorbers; UV stabilizers; antifogging agents; or dyes. The concentration of additives other than plasticizers (component d3) is typically 0 to 2 wt. %, particularly 0 to 1.5 wt. %, and especially 0 to 1 wt. % based on the total weight of the film of the present invention. The film of the present invention can contain 0.1 to 10 wt. % of plasticizer based on the total weight of the film of the present invention.

[0151] The preparation of biodegradable polymer blends from the individual components can be carried out by known methods (EP 792 309 and US 5,883,199), for example, all components of the mixture can be mixed in one process step in mixing equipment known to those skilled in the art, such as kneaders or extruders, at elevated temperatures, for example, 120°C to 300°C.

[0152] Preferably, the biodegradable polymer blend comprises: 10 to 80% by weight, in particular 15 to 50% by weight, in particular 20 to 40% by weight, of at least one biodegradable polyester a) as defined herein, based on the total weight of polyester a), polymer b) and polycaprolactone c), and in particular comprising at least 50% by weight, in particular at least 70% by weight, or at least 80% by weight, or at least 90% by weight, and even 100% by weight of an aliphatic-aromatic polyester, based on the total weight of polyester a); 18 to 88% by weight, in particular 35 to 70% by weight, in particular 40 to 70% by weight, of at least one polymer b) as defined herein, based on the total weight of polyester a), polymer b) and polycaprolactone c); 2 to 72% by weight, in particular 5 to 50% by weight, in particular 5 to 30% by weight, of at least one polycaprolactone c), based on the total weight of polyester a), polymer b) and polycaprolactone c), having a viscosity number, determined in accordance with DIN 53728-3:1985-1, in particular in the range of at least 150 ml / g, preferably 200 to 500 ml / g, in particular 250 to 450 ml / g; Including, The total weight of polyester a), polymer b), and polycaprolactone c) is at least 50% by weight, in particular at least 60% by weight, in particular at least 65% by weight or at least 70% by weight, based on the total weight of the blend, the remainder, if present, being typically selected from components d1), d2), and d3).

[0153] In particular, the biodegradable polymer blends are 10 to 80% by weight, in particular 15 to 50% by weight, in particular 20 to 40% by weight, of at least one biodegradable polyester a) as defined herein, based on the total weight of polyester a), polymer b) and polycaprolactone c), and in particular comprising at least 50% by weight, in particular at least 70% by weight, or at least 80% by weight, or at least 90% by weight, and even 100% by weight of an aliphatic-aromatic polyester, based on the total weight of polyester a); 18 to 88% by weight, in particular 35 to 70% by weight, in particular 40 to 70% by weight, of at least one polymer b) selected from the group consisting of polylactides and mixtures thereof, based on the total weight of polyester a), polymer b) and polycaprolactone c); 2 to 72% by weight, in particular 5 to 50% by weight, in particular 5 to 30% by weight, of at least one polycaprolactone c), based on the total weight of polyester a), polymer b) and polycaprolactone c), having a viscosity number, determined in accordance with DIN 53728-3:1985-1, in particular in the range of at least 150 ml / g, preferably 200 to 500 ml / g, in particular 250 to 450 ml / g; Including, The total weight of polyester a), polymer b), and polycaprolactone c) is at least 50% by weight, in particular at least 60% by weight, in particular at least 65% by weight or at least 70% by weight, based on the total weight of the blend, the remainder, if present, being typically selected from components d1), d2), and d3).

[0154] In a preferred group (A) of embodiments, the biodegradable polymer blend comprises: 50% to 90% by weight, in particular 60% to 87% by weight, in particular 65% to 82% by weight or 70% to 82% by weight of polyester a), polymer b), and polycaprolactone c), based on the total weight of the blend; 10 to 40% by weight, in particular 13 to 38% by weight, in particular 18 to 35% by weight, or 18 to 30% by weight, of one or more fillers (component d1)), based on the total weight of polyester a), polymer b), and polycaprolactone c), Includes; The remainder, if present, is typically selected from component d3).

[0155] In a particularly preferred group (A.1) of group (A), the biodegradable polymer blend is 50% to 90% by weight, in particular 60% to 85% by weight, in particular 65% to 78% by weight or 70% to 82% by weight of polyester a), polymer b), and polycaprolactone c), based on the total weight of the blend; 10 to 40% by weight, in particular 15 to 38% by weight, in particular 22 to 35% by weight, or 18 to 30% by weight, of one or more fillers (component d1)), based on the total weight of polyester a), polymer b), and polycaprolactone c); 0 to 2% by weight, in particular 0 to 1.5% by weight, in particular 0 to 1% by weight or 0 to 0.5% by weight of one or more components d3), based on the total weight of the blend; Includes.

[0156] In another particularly preferred group (A.2) of group (A), the biodegradable polymer blend is 50% to 90% by weight, in particular 60% to 86% by weight, in particular 65% to 81% by weight or 70% to 81% by weight of polyester a), polymer b), and polycaprolactone c), based on the total weight of the blend; 10 to 40% by weight, in particular 13 to 35% by weight, in particular 18 to 30% by weight, or 18 to 29% by weight, of one or more fillers (component d1)), based on the total weight of polyester a), polymer b), and polycaprolactone c); 0 to 2% by weight, in particular 0.1 to 1.5% by weight, in particular 0.2 to 1% by weight, of one or more components d3), based on the total weight of the blend; Includes.

[0157] The biodegradable polymer blends according to this preferred group (A) of embodiments are particularly suitable for processing by manufacturing methods such as thermoforming or injection molding. Thermoforming is a manufacturing process in which a plastic sheet is heated to a pliable forming temperature, typically below its melting temperature, and molded into a specific shape in a mold and trimmed to create a usable product. Injection molding is a manufacturing process in which parts are produced by injecting molten materials, such as thermoplastic and thermosetting polymers, into a mold.

[0158] The biodegradable polymer blends according to group (A) are particularly suitable for the production of rigid packaging.

[0159] In particular, the biodegradable polymer blends according to group (A.1) are particularly suitable for the production of rigid packaging by thermoforming.

[0160] In particular, the biodegradable polymer blends according to group (A.2) are also particularly suitable for the production of rigid packaging by injection moulding.

[0161] Optionally, the biodegradable polymer blend contains at least one compatibilizer. When present, the amount of compatibilizer is often 0.05 to 2 wt. % based on the total weight of the polymer blend. Preferred compatibilizers are additives containing carboxylic acid anhydrides, such as maleic anhydride-grafted (co)polymers of poly(butylene adipate-co-terephthalate), especially those copolymers containing epoxide groups and based on styrene, acrylate, and / or methacrylate. The epoxide-containing units are preferably glycidyl (meth)acrylate. Epoxide-containing copolymers of the above-mentioned type are sold, for example, by BASF under the brand name Joncryl® ADR. For example, Joncryl® ADR 4468 and Joncryl® ADR 4400 are particularly suitable as compatibilizers.

[0162] Optionally, the biodegradable polymer blend comprises: 50 to 95% by weight, in particular 60 to 90% by weight, in particular 70 to 88% by weight of polyester a), polymer b), and polycaprolactone c), based on the total weight of the blend; If present, 0.05 to 2 wt. % of at least one compatibilizer, particularly at least one poly(meth)acrylate containing epoxide groups, based on the total weight of the blend. Includes.

[0163] The polymer blends may be used as dry blends or compounds.

[0164] The biodegradable polymer blends according to the present invention are suitable for the manufacture of monolayer and multilayer films and for coating substrate layers. As mentioned above, the polymer blends of the present invention improve adhesion at high coating line speeds.

[0165] The present invention therefore relates to monolayer and multilayer films comprising or consisting of at least one layer comprising or consisting of a biodegradable polymer blend as defined herein. The present invention also relates to the use of a biodegradable polymer blend as defined herein for coating a substrate layer.

[0166] Throughout this specification, the term "monolayer film" should be understood as a film that includes only a single layer, and the term "multilayer film" should be understood as a film that includes at least two layers, respectively. In this context, such multilayer films do not necessarily include a substrate layer onto which the film can be coated.

[0167] Cast film extrusion, blown film extrusion, extrusion coating, and lamination processes are suitable for producing the monolayer and multilayer films according to the present invention. Combinations of these processes are also contemplated.

[0168] The biodegradable polymer blends of the present invention are suitable for coating a substrate layer in a single layer, also known as a monolayer coating, and for coating a substrate in two or more layers, i.e., multiple layers, also known as a multilayer coating.

[0169] The average basis weight is generally 5 to 50, preferably 10 to 30 g / m for a single layer coating. 2 In the case of multi-layer coating, it is generally 10 to 60, preferably 15 to 35 g / m 2 is.

[0170] Basis weight is determined by punching a circular panel, typically 4.5 inches (114.3 mm) in diameter. The circular panel is weighed both before and after coating. From the weight difference and the known area, the basis weight is calculated in g / m². 2 It is possible to report it at

[0171] Multilayer coating is a completely conventional method, especially for paper or cardboard coating. Typically, two to seven layers are applied, preferably two or three. Multilayer coating offers the possibility of individually optimizing the welding properties, barrier properties, and adhesion of the coating to the substrate layer. Furthermore, a single or multiple layer can serve as a primer layer for subsequent coatings, e.g., lamination, providing good adhesion, a smooth surface, or both.

[0172] Therefore, the outer or top layer of a multilayer coating must, in principle, be scratch-resistant, heat-stable, and have little to no tack, for example, and must have a reduced tendency to exhibit tack, simply to avoid the film sticking to the chill roll during the manufacturing process.

[0173] In a particular embodiment, the outer layer comprises 80 to 100 wt. %, in particular 85 to 99.9 wt. %, in particular 90 to 99 wt. %, of a biodegradable polymer blend as defined herein, based on the total weight of the outer layer, and optionally, if present, 0 to 20 wt. %, in particular 0.3 to 13 wt. %, in particular 3 to 10 wt. %, of a wax formulation comprising a wax, a dispersant, and an antiblocking agent, based on the total weight of the outer layer.

[0174] The wax formulation preferably comprises 0 to 5 wt. %, in particular 0.1 to 4 wt. %, and in particular 1 to 3 wt. % of wax, based on the total weight of the outer layer; 0 to 10 wt. %, in particular 0.1 to 5 wt. %, and in particular 1 to 4 wt. % of dispersing agent, based on the total weight of the outer layer; and 0 to 5 wt. %, in particular 0.1 to 4 wt. %, and in particular 1 to 3 wt. % of antiblocking agent, based on the total weight of the outer layer.

[0175] Suitable examples of waxes, dispersants, and antiblocking agents used in the wax formulation, as well as their preferred counterparts, are described above.

[0176] Suitable examples of dispersants for use in the wax formulation include, but are not limited to, stearic acid, metal salts of oleic acid, N,N'-ethylenebisstearamide, fatty acid amides such as erucamide, oleamide.

[0177] Suitable examples of anti-blocking agents for use in the wax formulation include, but are not limited to, calcium carbonate, silica, talc, behenamide, stearamide, N,N'-ethylene-bis-oleamide.

[0178] When a multilayer coating contains at least three layers, the layer between the outer layer and the layer coated directly on the substrate is called the intermediate layer. The intermediate layer is generally more rigid and may also be called the substrate layer or barrier layer. In thin-film paper coatings, the intermediate layer can be omitted entirely.

[0179] At least one layer comprises at least one aliphatic-aromatic polyester. Suitable examples of the aliphatic-aromatic polyester used in at least one layer include, but are not limited to, the aliphatic-aromatic polyesters described above. Examples include poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene sebacate-co-terephthalate) (PBSeT), poly(butylene azelate-co-terephthalate) (PBAzT), poly(butylene adipate-co-furanoate) (PBAF), poly(butylene sebacate-co-furanoate) (PBSeF), poly(butylene azelate-co-furanoate) (PBAzF), poly(butylene adipate-co-seb Particularly preferred are aliphatic-aromatic polyesters selected from poly(butylene adipate-co-azelate-co-terephthalate) (PBASeT), poly(butylene adipate-co-azelate-co-furanoate) (PBAAzF), poly(butylene adipate-co-azelate-terephthalate) (PBAAzT), poly(butylene succinate-co-furanoate) (PBSF), and poly(butylene adipate-co-sebacate-co-furanoate) (PBASeF).

[0180] The inner layer is the layer that contacts the substrate layer, and therefore, in principle, it should be soft and adhere well to the substrate layer.

[0181] Suitable examples of aliphatic-aromatic polyesters for use in the intermediate and inner layers, as well as preferred examples thereof, are described above.

[0182] The present invention also provides a method of coating a substrate layer, comprising the steps of: A) providing a substrate layer; B) coating the substrate with at least one layer comprising a biodegradable polymer blend as defined herein; The present invention relates to a method, comprising:

[0183] Step B), i.e. the coating of the substrate with at least one layer comprising the biodegradable polymer blend as defined herein, is preferably carried out by extrusion coating, coextrusion coating or lamination, such as extrusion lamination or adhesive lamination, in particular by extrusion coating or coextrusion coating.

[0184] Extrusion and coextrusion coating methods have been developed to apply thin polymer layers to flexible substrates, such as paper, cardboard, or multilayer films containing metal layers, at high web speeds of 100 to 600 m / min. The biodegradable polymer blends described herein can be processed using existing extrusion coating plants for polyethylene, as described in J. Nentwig: Kunststofffolien, Hanser Verlag, Munich 2006, p. 195; HJ Saechtling: Kunststoff Taschenbuch, Hanser Verlag, Munich 2007, p. 256; C. Rauwendaal: L Polymer Extrusion, Hanser Verlag, Munich 2004, p. 547.

[0185] Lamination is a method for producing composite systems with improved strength, stability, and appearance by using two or more materials, such as a substrate layer and a film layer, or two film layers, assembled using heat, pressure, welding, or adhesives. Suitable lamination methods for joining a substrate layer and at least one film layer, or two or more films, to obtain a laminate are extrusion lamination and adhesive lamination. The polymer blend of the present invention can be processed using lamination methods known to those skilled in the art.

[0186] Generally, any material can be used as the substrate layer as long as it is suitable for application in the method according to the present invention. Examples of suitable substrate layers include, but are not limited to, fiber-based substrates such as paper, cardboard, paperboard, or fiberboard. In this regard, the raw materials for paper, cardboard, and fiberboard may be wood, wood products, or recycled pulp, as well as other plant fibers. Suitable examples of other plant fibers include, but are not limited to, fibers from sugarcane, bamboo, grasses, or silphium.

[0187] The substrate layer is preferably a fibrous substrate such as paper, cardboard, paperboard, or fiberboard, especially paper.

[0188] In particular, step B) is carried out by coating a substrate layer with two or more layers, i.e. multiple layers, comprising the biodegradable polymer blend as defined herein, using extrusion coating, coextrusion coating, lamination such as extrusion lamination or adhesive lamination, or thermoforming, preferably coextrusion coating, wherein the substrate layer is a fiber-based substrate, in particular paper or cardboard.

[0189] In particular, the coating in step B) is carried out by extrusion coating, coextrusion coating, lamination with a monolayer or multilayer film, or by thermoforming.

[0190] In a preferred embodiment, step B is carried out by coating the substrate layer with at least one layer comprising a biodegradable polymer blend as defined herein, and optionally one or more further layers formed by a biodegradable material other than the biodegradable polymer blend as defined herein in one of the layers.

[0191] Suitable examples of biodegradable materials other than the biodegradable polymer blends defined herein include, but are not limited to, metallized or otherwise inorganically coated biodegradable polymer films, cellophane, PLANTIC™ barrier film sold by Kuraray Co., Ltd., polyvinyl alcohol (PVOH), particularly PVOH commercially available under the trade name G-polymer™, ethylene vinyl alcohol (EVOH), hydrolyzed polyvinyl acetate (PVOAc), and polyglycolic acid (PGA), and copolymers thereof.

[0192] The advantages mentioned above also apply to laminates comprising at least one film according to the present invention. Accordingly, the present invention further relates to a laminate comprising at least one film according to the present invention and a substrate to which the film is laminated. Furthermore, the present invention relates to a laminate obtainable by the method for coating a substrate layer defined herein.

[0193] Throughout this specification, the term "laminate" should be understood as a composite system made by lamination using two or more materials, such as a substrate layer and a film layer or two film layers, assembled using heat, pressure, welding, or adhesives.

[0194] In particular, step B) and / or lamination can be carried out using heat and pressure to achieve the desired shape (thermoforming). Thermoforming is a common lamination method for paper packaging in which heat and pressure are used to simultaneously form a substrate, including a film.

[0195] In the context of the present invention, a laminate can comprise either one or more substrate layers and one or more film layers together, or one or more substrate layers only, or one or more film layers only.

[0196] One or more film layers can be barrier layers that prevent atmospheric gases, such as O2 or N2, and / or moisture or liquids from permeating. Examples of such barrier layers include, but are not limited to, metal layers and wax; metal oxides such as silicon oxide or aluminum oxide; lignin and / or oligosaccharides or polysaccharides; proteins; and layers that include or consist of ethylene-vinyl alcohol copolymers, such as hydrolyzed ethylene vinyl acetate copolymers. Preferably, such barrier layers should be compostable.

[0197] The method according to the invention is suitable for coating packaging such as packaging for food, beverages, nutritional products, personal care products, cleansing and detergents; paper and cardboard cups and plates; carrier bags; paper adhesive tape; paper labels; flower pots; and substrates used for producing flower pots.

[0198] The present invention therefore also relates to packaging, such as packaging for food, beverages, nutritional products, personal care products, cleansing and detergents, comprising at least one film according to the present invention or a laminate as defined herein; paper and cardboard cups and plates; carrier bags; paper adhesive tape; paper labels; flower pots; and materials selected from flower pots.

[0199] Furthermore, the method according to the invention is particularly suitable for coating paper to produce paper bags for dry foods, for example for coffee, tea, soup powders, sauce powders, etc.; paper bags for liquids, for example for cosmetics, cleansers, beverages, etc.; tube laminates; paper carrier bags; paper laminates and coextrusions for ice cream, confectionery (e.g. chocolate bars and muesli bars), paper adhesive tape; cardboard cups (paper cups, yogurt pots; meal trays; rolled cardboard containers (cans, drums); wet-strength cartons for outer packaging (wine bottles, food); coated cardboard fruit boxes; fast food plates; clamshells; beverage cartons and cartons for liquids, such as detergents and cleansers, frozen food cartons, ice packaging (e.g. ice cups, wrapping material for cone-shaped ice cream wafers); paper labels; flower pots and flower pots.

[0200] The blends of the present invention can also be used in rigid packaging applications. In contrast to flexible packaging, rigid packaging is understood to be packaging with a predetermined shape. Therefore, a further aspect of the present invention relates to the use of the blends defined herein in the manufacture of rigid packaging articles.

[0201] Rigid packaging is typically produced by thermoforming sheets or laminates containing the blends of the present invention or by injection molding of the blends of the present invention. Thermoforming and injection molding can be carried out in a manner similar to well-known processes for thermoforming and injection molding, respectively, of thermoplastic materials.

[0202] In thermoforming, sheets or laminates can be made of plastic materials containing one or more layers formed from the blends of the present invention. However, it is also possible to produce rigid packaging by thermoforming sheets or laminates containing a base layer made of a fibrous material, such as a paper or cardboard layer, coated with one or more thermoplastic layers containing at least one layer of the blends of the present invention. Sheets or laminates used to produce rigid packaging by thermoforming preferably have at least one outer layer formed from the blends of the present invention. Sheets or laminates used to produce rigid packaging by thermoforming preferably have at least one barrier layer. For example, laminates with an ABC structure (A and C refer to layers formed from the blends of the present invention, but are not necessarily identical, and B refers to the barrier layer) can be used. Rigid packaging articles with the same ABC structure can also be prepared by injection molding, for example, co-injection molding.

[0203] Thus, the present invention also relates to a method for producing a rigid packaging article, comprising the step of forming, by thermoforming or injection molding, a polymer blend of the present invention, or a single or multi-layer sheet or laminate comprising a polymer blend of the present invention.

[0204] Example The present invention will be explained in more detail by the following examples.

[0205] 1 Analysis 1.1 Measurement of performance characteristics: The seal strength of paper substrates coated with polymer films was determined using a Kopp sealing device LM 3000 at a pressure of 500 bar and a dwell time of 0.2 seconds. Two different sealing times of 0.2 seconds and 0.5 seconds were applied to Sappi and CFN papers, respectively. The towing speed was 12 m / min.

[0206] Adhesion evaluation was performed by an expert. First, an expert peeled the applied polymer coating from the paper substrate using his or her own hands. The resulting peel area of ​​the pre-bonded paper substrate and polymer film was then evaluated for fiber breakage or fiber adhesion according to the adjacent scheme. Adhesion was evaluated on a scale of 1 to 5 (0 = "no adhesion," 1 = "slight adhesion," 2 = "some torn fibers," 3 = "less than 50% fiber tear," 4 = "more than 50% fiber tear," 4.5 = "more than 90% fiber tear," and 5 = "100% fiber tear; perfect adhesion").

[0207] 1.2 Maximum line speed To determine the maximum line speed (m / min), the plant is started slowly and the plant speed is increased continuously until the maximum possible coating speed is reached.

[0208] 1.3 Viscosity number of PCL (VN) As mentioned above, the viscosity number (VN) was determined according to DIN 53728-3:1985-1. The viscosity number is determined at 25°C using a solution of the respective polymer in a 50:50 w / w mixture of phenol and 1,2-dichlorobenzene.

[0209] 1.4 Number average molecular weight (Mn) As described above, Mn was determined by GPC with a refractive index (RI) detector using a mixture of hexafluoroisopropanol and 0.05% potassium trifluoroacetate as the eluent (temperature: 40 °C, flow rate: 1 mL / min) and polymethyl methacrylate of defined molecular weight as the calibration standard.

[0210] 1.5 MVR: MVR (Melt Volume Rate) of polymers and polymer blends was measured according to EN ISO 1133 at 190°C with a weight of 2.16 kg unless otherwise indicated.

[0211] 1.6 Elastic Modulus: The modulus of elasticity was measured according to ISO 527-2:2012 on dumbbell-shaped specimens (specimen type 1A) with a thickness of approximately 3.95 mm at 23°C and 50% relative humidity.

[0212] 1.7 Heat Deflection Temperature (HDT / B) The heat deflection temperature (HDT / B) was determined according to DIN EN ISO 75-2:2004-9 using planar orientation of 80 mm x 10 mm x 4 mm specimens. Method B with a stress of 0.45 MPa and a temperature rise rate of 120 K / h was used.

[0213] 2. Experimental Setup: 2.1 Paper coating The extruder setup of the pilot coating plant included four separate extruders, two of which were used for the experiments (Extruders A and B) - see Table A. The feed of a single extruder can be selected using a selector plug, allowing for the application and encapsulation of multilayer structures of up to five layers. For single-layer coatings, only the feed of the main extruder A was used. The polymer melt was fed onto the substrate through an internal deck extrusion T-die (Cloern EBR™ III A) with edge encapsulation.

[0214] [Table 1]

[0215] The paper substrate used was 58 g / m 2 Sappi Magnostar ("Sappi") having a basis weight of 195 g / m 2 The substrates were Cupforma Natura ("CFN") papers manufactured by Stora Enso with a basis weight of 1000 mm and their width was 500 mm. The substrates were activated by corona treatment (3.2 kV).

[0216] All coatings were extruded onto paper substrates at melt temperatures between 235 and 260 °C. The temperatures in temperature profile zones 1 to 7 were 170 °C, 195 °C, 210 °C, 230–240 °C, 220–240 °C, 220–240 °C, and 220–240 °C, respectively. The pressure at the nozzle was 100 bar, and the normal contact pressure on the chill roll was 6 bar. The chill roll was glossy. The throughput was kept constant, and the substrate speed was increased in stages from 80 to 360 m / min.

[0217] 2.2 Polymer Blend Production Polymers used to make the blend: Polyester 1: 6+ / -2cm according to EN ISO 1133 (190℃, 2.16kg weight) 3 Poly(butylene sebacate-co-terephthalate) with an MVR (190°C, 2.16 kg) of 10 min.

[0218] Polyester 2: 10+ / -2cm according to EN ISO 1133 (190℃, 2.16kg weight) 3 Poly(butylene adipate-co-terephthalate) available from BASF SE as ecoflex F Blend C1300 with an MVR (190°C, 2.16 kg) of 10 min.

[0219] Polylactide (PLA): A biopolymer comprising polylactide with an MVR (190°C, 2.16 kg) of 32-38 g / 10 min, which is commercially available from Natureworks under the brand Ingeo™ 3251D.

[0220] Polycaprolactone 1 (PCL1): A high molecular weight linear polyester derived from caprolactone monomers having a viscosity number of 375.5 ml / g, determined in accordance with DIN 53728-3:1985-1, and an Mn of 39,000 g / mol, determined by GPC. It is commercially available from Ingevity under the brand name Capa™ 6800.

[0221] Polycaprolactone 2 (PCL2): A high molecular weight linear polyester derived from caprolactone monomers having a viscosity number of 137.5 ml / g, determined in accordance with DIN 53728-3:1985-1, and an Mn of 24,000 g / mol, determined by GPC. It is commercially available from Ingevity under the brand name Capa™ 6400.

[0222] Polycaprolactone 3 (PCL3): A high molecular weight linear polyester derived from caprolactone monomers having a viscosity number of 224.1 ml / g, determined in accordance with DIN 53728-3:1985-1, and an Mn of 30,000 g / mol, determined by GPC. It is commercially available from Ingevity under the brand name Capa™ 6500.

[0223] Filler: Talc powder commercially available from Elementis under the brand name Plustalc H05C.

[0224] Additives: Erucamide commercially available from Croda under the brand name Crodamide™ ER.

[0225] All blends were prepared by extrusion using a Coperion ZSK 26 MC twin-screw extruder (11 zones; zone 2 = 140°C, zones 3 to 11 = 190°C) at a rotation speed of 300 rpm. The individual components were added by separate weight scales in zone 1 and melted and mixed in the following zones. The polymer melt was degassed in zone 9 at 600 mbar. The die plate temperature was between 215 and 225°C. The resulting compound was strand pelletized. The amounts of the polymer components forming the blends of comparative examples CE1 and CE2 and inventive examples IE1 and IE2 are summarized in Table B below. The amounts of the blend components are given in weight % based on the total weight of the blend.

[0226] [Table 2]

[0227] 3. Examples and Results 3.1 Comparative example CE1 The compounds were applied as a single layer via main extruder A. The melt temperature was approximately 238°C in all cases.

[0228] 3.2 Comparative Example CE2, Inventive Examples IE1 and IE2 Further paper substrate coatings were carried out in the same manner as Comparative Example CE1, varying the polymer and / or amount of polymer used as shown in Table B above.

[0229] Table C below summarizes further coating conditions and adhesion results for CE1, CE2, IE1, and IE2. Adhesion was rated on a scale of 1 to 5 (0 = "no adhesion", 1 = "slight adhesion", 2 = "some torn fibers", 3 = "less than 50% fiber tear", 4 = "more than 50% fiber tear", 4.5 = "more than 90% fiber tear", 5 = "100% fiber tear; perfect adhesion").

[0230] [Table 3]

[0231] Additionally, Table D below summarizes the coating conditions and seal strength results for CE1, CE2, IE1, and IE2.

[0232] [Table 4]

[0233] 3.3 Comparative Example CE3 and Inventive Examples IE3 and IE4 To investigate the effect of PLA content on processability in an extrusion coating line, extrusion coatings were carried out using polyester 1, PLA, and PCL 1 or 2, varying the amounts of the single components. The weight ratios of the components used and the maximum line speeds achieved are summarized in the table below.

[0234] [Table 5]

[0235] It was shown that a relatively high PLA content is necessary for processability in extrusion coating lines.

[0236] 3.4 Implementation of the present invention IE5, IE6, and IE7 To investigate the effect of viscosity number of PCL on processability in an extrusion coating line, extrusion coating was carried out using Polyester 1, PLA, and PCL 1 and 3, varying the amounts of the single components. The weight ratios of the components used and the maximum line speeds achieved are summarized in the table below.

[0237] [Table 6]

[0238] 3.5 Comparative Example CE4 and Inventive Example IE8 The following blends were prepared as described above and are particularly suitable for the production of rigid packaging by injection molding the blends.

[0239] [Table 7]

[0240] [Table 8]

[0241] As shown, the introduction of PCL increases stiffness without dramatically affecting other properties such as thermal stability and flowability. Thus, the blends are particularly suitable for producing rigid packaging.

Claims

1. 10 to 80 wt. % of at least one biodegradable polyester a) selected from the group consisting of aliphatic-aromatic polyesters different from polymers b) and c), aliphatic polyesters, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 18 to 88 wt. % of at least one polymer b) selected from the group consisting of polyhydroxyalkanoates, polylactides, polyglycolic acids, and mixtures thereof, based on the total weight of polyester a), polymer b), and polycaprolactone c); 2 to 72 wt. % of at least one polycaprolactone c) having a viscosity number of at least 110 ml / g, determined in accordance with DIN 53728-3:1985-1, based on the total weight of polyester a), polymer b), and polycaprolactone c), Including, A biodegradable polymer blend, wherein the total weight of polyester a), polymer b), and polycaprolactone c) is at least 50% by weight, based on the total weight of the blend.

2. 2. The biodegradable polymer blend of claim 1, wherein the weight ratio of polyester a) to the sum of polymer b) and polycaprolactone c) is in the range of from 10:90 to 80:20, preferably from 15:85 to 50:50, more preferably from 20:80 to 45:

55.

3. 3. The biodegradable polymer blend according to claim 1 or 2, wherein the weight ratio of polymer b) to polycaprolactone c) is in the range of from 9:1 to 1:4, preferably from 9:1 to 1:3, more preferably from 9:1 to 1:

2.

4. 4. The biodegradable polymer blend according to claim 1, wherein the amount of polyester a) is in the range of 15 to 50% by weight, in particular 20 to 40% by weight, the amount of polymer b) is in the range of 35 to 70% by weight, in particular 40 to 70% by weight, and the amount of polycaprolactone c) is in the range of 5 to 50% by weight, in particular 5 to 30% by weight, based on the total weight of polyester a), polymer b), and polycaprolactone c).

5. 5. The biodegradable polymer blend according to claim 1, wherein the number average molecular weight of the polycaprolactone c) is at least 20,000 g / mol, in particular at least 25,000 g / mol, preferably at least 28,000 g / mol, in particular at least 31,000 g / mol, determined by GPC.

6. The polyester a) is 0.5 to 70 cm ３ / 10 min, preferably 1 to 65 cm ３ / 10 min, more preferably 1 to 60 cm ３ 6. The biodegradable polymer blend according to claim 1, having a melt volume rate (MVR) according to EN ISO 1133 (190°C, 2.16 kg weight) in the range of 0.15 / 10 minutes.

7. EN ISO 1133 (190°C, 2.16 kg weight) 1-35 cm ３ / 10 min range, preferably 1 to 30 cm ３ / 10 minutes range, more preferably 1.5 to 25 cm ３ 7. The biodegradable polymer blend of claim 1, having a melt volume rate (MVR) in the range of 1 / 10 minutes.

8. 8. The biodegradable polymer blend of claim 1, wherein polymer b) is selected from the group consisting of polylactides.

9. Polyester a) is poly(butylene adipate-co-terephthalate), poly(butylene sebacate-co-terephthalate), poly(butylene azelate-co-terephthalate), poly(butylene succinate-co-terephthalate), poly(butylene adipate-co-sebacate-co-terephthalate), poly(butylene adipate-co-azelate-co-terephthalate), poly(butylene adipate-co-succinate-co-terephthalate), poly(butylene sebacate-co-azelate-co-terephthalate), poly(butylene sebacate-co-succinate-co-terephthalate), poly(butylene azelate-co-succinate-co-terephthalate), poly(butylene adipate-co-furanoate), poly(butylene sebacate-co-furanoate), poly 9. The biodegradable polymer blend of any one of claims 1 to 8, wherein the polymer is selected from the group consisting of poly(butylene azelate-co-furanoate), poly(butylene succinate-co-furanoate), poly(butylene adipate-co-sebacate-co-furanoate), poly(butylene adipate-co-azelate-co-furanoate), poly(butylene adipate-co-succinate-co-furanoate), poly(butylene sebacate-co-azelate-co-furanoate), poly(butylene sebacate-co-succinate-co-furanoate), poly(butylene azelate-co-succinate-co-furanoate), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(butylene succinate-co-sebacate), and mixtures thereof.

10. A monolayer or multilayer film comprising or consisting of at least one layer comprising or consisting of a biodegradable polymer blend according to any one of claims 1 to 9.

11. 10. Use of the biodegradable polymer blend according to any one of claims 1 to 9 for coating a substrate layer or for producing a rigid packaging article.

12. 1. A method of coating a substrate layer, comprising: A) providing a substrate layer; Step B) of coating the substrate with one or more polymer layers, at least one of the polymer layers comprising or consisting of the biodegradable polymer blend according to any one of claims 1 to 9; A method comprising:

13. 13. The method according to claim 12, wherein the coating in step B) is carried out by extrusion coating, co-extrusion coating, lamination with a monolayer or multilayer film, or thermoforming.

14. 14. The use or method of any one of claims 11 to 13, wherein the substrate layer is a fiber-based substrate such as paper, cardboard, paperboard, or fiberboard.

15. A laminate comprising at least one film of claim 10 and a substrate to which the film is laminated.

16. A laminate obtainable by the method according to any one of claims 12 to 13.

17. 17. Materials selected from packaging such as packaging for food, beverages, nutritional products, personal care products, cleansing and detergents, comprising at least one film according to claim 10 or a laminate according to any one of claims 15 or 16; paper and cardboard cups and plates; carrier bags; paper adhesive tape; paper labels; flower pots; and flower pots.

18. 10. A method for producing a rigid packaging article, the method comprising the step of forming by thermoforming or injection molding a polymer blend according to any one of claims 1 to 9, or a mono- or multi-layer sheet or laminate comprising a polymer blend according to any one of claims 1 to 9.

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