Biodegradable coated paper product and method thereof

Abstract

A biodegradable coated paper product comprising a paper substrate and a layer disposed on the paper substrate wherein the layer is formed from a biodegradable coating composition comprising: a. A cellulose ester which is cellulose acetate propionate (CAP) in an amount of 5.5 to 15 weight percent based on the total weight of (a), (b) and (c); b. A biodegradable polymer which is a polyester in an amount of from 45 to 75 wt% based on the total weight of (a), (b) and (c); and c. An inorganic filler in an amount of 12 to 40 wt%, based on the total weight of (a), (b), and (c); wherein the polyester is selected from the group consisting of poly (butylene succinate) (PBS), poly (butylene succinate adipate) (PBSA), polycaprolactone (PCL), poly (butylene adipate terephthalate) (PBAT), polylactic acid (PLA), and combinations thereof.

Description

Technical Field

[0001] The embodiments disclosed herein generally relate to biodegradable coated paper products and methods for manufacturing biodegradable coated paper products. Background Technology

[0002] Generally speaking, paper products (such as paper cups, bowls, plates, boxes, lunch boxes, beverage containers, non-woven fabrics, and paper containers) are increasingly popular with consumers because they are considered more natural, biodegradable, and recyclable. Uncoated paper-based packaging is often highly biodegradable under certain conditions and is easily recycled in commercial paper recycling systems. However, paper without any coating or adhesive cannot be easily formed into paper products. Furthermore, uncoated paper products have poor water / moisture barrier properties.

[0003] To improve barrier properties, polyethylene polymers or other non-biodegradable polymers are coated onto the surface of paper. However, if the coating is too thick, it can negatively impact the recyclability of the paper laminate in a typical commercial paper recycling system. Examples of such problems include: i) the coating clogging repulping tanks and filters in the system; ii) the coating adhering tightly to the paper fibers, preventing a high percentage of paper fibers from being released into the water of the repulping system; iii) the coating eventually being incorporated into the recycled paper, negatively affecting the appearance or performance properties of the resulting recycled paper. If the coating is made too thin, the overall structure can be considered recyclable in the paper recycling stream if it can be peeled off and sent to a landfill or incinerated to provide fuel for the plant, leaving the paper fibers to be collected and recycled back into the paper. However, this structure still has several drawbacks because the paper will biodegrade if it is not disposed of properly in the environment, but the polyethylene coating or other non-biodegradable coating will not. This can lead to persistent microplastics, negatively impacting the environment or becoming a non-nutritive food source for some animals.

[0004] To address the challenges of using polyethylene-based polymers or other non-biodegradable polymers, bio-based and biodegradable materials are being developed. However, some novel bio-based and biodegradable materials exhibit poor processability (slow coating and conversion rates), poor paper adhesion with thin coatings, and high water vapor permeability.

[0005] To address some of these issues, manufacturers have sought to modify existing coating / conversion machines and apply thicker coatings. However, these changes have significantly increased costs and slowed the biodegradation rate of coated paper products.

[0006] Therefore, there is still a need for a biodegradable coating composition that can be applied to paper more effectively, has good paper adhesion and a thin coating, resulting in paper products with low water vapor permeability and a fast biodegradation rate. Summary of the Invention

[0007] The embodiments herein disclose biodegradable coated paper articles. The articles comprise a paper substrate and a layer disposed on the paper substrate, wherein the layer is formed of a biodegradable coating composition comprising (optionally, substantially comprising or consisting of): a. a cellulose ester, wherein the cellulose ester is cellulose acetate propionate (CAP), in an amount of 5.5 to 15 wt% based on the total weight of (a), (b), and (c); b. a biodegradable polymer, wherein the biodegradable polymer is polyester, in an amount of 45 to 75 wt% based on the total weight of (a), (b), and (c); and c. an inorganic filler, in an amount based on (a) The total weight of (b) and (c) is 12 to 40% by weight; wherein the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), and combinations thereof, wherein the average degree of substitution (DSOH) of hydroxyl substituents in CAP is 0.3 to 1.2, the average degree of substitution (DSAc) of acetyl substituents is 0 to 0.5, and the average degree of substitution (DSPr) of propionyl substituents is 1.8 to 2.7, and according to ASTM The falling ball viscosity measured by D-1343 is 0.05 to 30 seconds; the glass transition temperature (Tg) of the biodegradable coating composition is -40 to -10°C, the melting temperature (Tm) is 80 to 110°C, the crystallization temperature (Tc) is 40 to 70°C, and the Young's modulus of the biodegradable coating composition is greater than 700 MPa, the elongation at break is 10% to 300%, and the water vapor transmission rate (WVTR) is less than 600 g·mil / (m 2 ·sky).

[0008] The embodiments herein also disclose a method for manufacturing a biodegradable coated paper article. The method includes: providing a paper substrate; and extruding a layer onto the paper substrate to form a biodegradable coated paper article, wherein the layer is formed of a biodegradable coating composition comprising (optionally, substantially comprising or consisting of): a. a cellulose ester, wherein the cellulose ester is cellulose acetate propionate (CAP), in an amount of 5.5 to 15% by weight based on the total weight of (a), (b), and (c); b. a biodegradable polymer, wherein the biodegradable polymer is a polyester, in an amount of 45 to 75% by weight based on the total weight of (a), (b), and (c); and c. an inorganic filler. The amount of which is 12 to 40% by weight based on the total weight of (a), (b), and (c); wherein the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), and combinations thereof; wherein the average degree of substitution (DSOH) of the CAP is 0.3 to 1.2, the average degree of substitution (DSAc) of the acetyl substituent is 0 to 0.5, the average degree of substitution (DSPr) of the propionyl substituent is 1.8 to 2.7, and according to ASTM The falling ball viscosity measured by D-1343 is 0.05 to 30 seconds; the glass transition temperature (Tg) of the biodegradable coating composition is -40 to -10°C, the melting temperature (Tm) is 80 to 110°C, the crystallization temperature (Tc) is 40 to 70°C, and the Young's modulus of the biodegradable coating composition is greater than 700 MPa, the elongation at break is 10% to 300%, and the water vapor transmission rate (WVTR) is less than 600 g·mil / (m 2 ·sky).

[0009] In one or more embodiments herein, the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), poly(butylene terephthalate adipate) (PBAT), or mixtures thereof.

[0010] In one or more embodiments of this document, the inorganic filler is calcium carbonate.

[0011] In one or more embodiments herein, the amount of inorganic filler is 20 to 40 by weight of the biodegradable coating composition.

[0012] In one or more embodiments herein, the average degree of substitution of hydroxyl substituents in the CAP is 0.5 to 1.0, the average degree of substitution of acetyl substituents (DSAc) is 0 to 0.2, the average degree of substitution of propionyl substituents (DSPr) is 2.0 to 2.5, and the falling ball viscosity, as measured according to ASTM D-1343, is 0.1 to 5 seconds.

[0013] In one or more embodiments herein, the crystallization temperature (Tc) of the biodegradable coating composition is 40 to 60°C.

[0014] In one or more embodiments herein, the biodegradable coating composition has a viscosity (V200) of 500 to 800 Pa·s at 200 °C and 10 rad / s, and a viscosity ratio (V65 / V200) of less than 28, wherein V65 is the viscosity measured at 65 °C and 10 rad / s.

[0015] In one or more embodiments herein, the weight of the paper substrate is from 50 gsm to 350 gsm. Detailed Implementation

[0016] Reference will now be made in detail to embodiments of biodegradable coated paper products and methods for manufacturing them. Biodegradable coated paper products can be used to manufacture food and beverage containers, such as cups, plates, bowls, gable-top cartons, folding cartons, paper bags, and sandwich wraps. However, it should be noted that these are merely illustrative embodiments disclosed herein. These embodiments are also applicable to other technologies susceptible to similar problems, such as paper bags, paper tape, paper labels, and ream wraps.

[0017] In embodiments described herein, biodegradable coated paper articles and methods of manufacturing the same include a paper substrate and a layer disposed on the paper substrate, wherein the layer is formed of a biodegradable coating composition. The paper substrate has a weight base of 50 gsm to 350 gsm. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the weight base of the paper substrate ranges from a lower limit of 50, 75, 100, 125, or 150 gsm to an upper limit of 350, 300, 250, 200, or 150 gsm. The paper substrate may be made of cellulose or lignocellulose materials. Examples of cellulose raw materials include paper and paper products, such as newsprint, polycoated paper, and papermaking waste liquid; examples of lignocellulosic raw materials include wood, wood fibers, and wood-related materials, as well as materials derived from kenaf, grass, rice husks, bagasse, cotton, jute, other stem plants (e.g., hemp, flax, bamboo; bast and core fibers), leaf plants (e.g., sisal, abaca), and agricultural fibers (e.g., cereal straw, corn cobs, rice husks, and coconut fuzz). In addition to natural raw materials, post-consumer or post-industrial recycled materials, industrial waste (e.g., industrial byproducts), and processing waste (e.g., waste liquids) can also be used as fiber sources.

[0018] The layer is formed of a biodegradable coating composition comprising (a) a cellulose ester, (b) a biodegradable polymer, and (c) an inorganic filler. In one or more embodiments herein, the biodegradable coating composition comprises 5.5 wt% to 15 wt% of the cellulose ester as described herein, based on the total weight of (a), (b), and (c). All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the biodegradable coating composition comprises 5.5, 5.8, 6.0, 6.2, or 6.5 wt% to 15, 14, 13, or 12.5 wt% of the cellulose ester, based on the total weight of (a), (b), and (c). In other embodiments, the biodegradable coating composition comprises 5.5 wt% to 14 wt%, 5.8 wt% to 14 wt%, or 6.0 wt% to 12.5 wt% of the cellulose ester, based on the total weight of (a), (b), and (c). In one or more embodiments herein, the biodegradable coating composition comprises, based on the total weight of (a), (b), and (c), 45 wt% to 75 wt% of the biodegradable polymer as described herein. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the biodegradable coating composition comprises, based on the total weight of (a), (b), and (c), 45, 47.5, 50, 52.5, or 55 wt% to 75, 72.5, 70, 67.5, or 65 wt% of the biodegradable polymer. In other embodiments, the biodegradable coating composition comprises, based on the total weight of (a), (b), and (c), 45 wt% to 72.5 wt%, 47.5 wt% to 72.5 wt%, or 50 wt% to 72.5 wt% of the biodegradable polymer. In one or more embodiments herein, the biodegradable coating composition comprises, based on the total weight of (a), (b), and (c), 12 to 40 wt% of the inorganic filler as described herein. All individual values ​​and subranges are included and disclosed herein. For example, in some embodiments, based on the total weight of (a), (b), and (c), the biodegradable coating composition comprises 12, 15, 17.5, or 20% by weight to 40, 37.5, or 35% by weight of inorganic filler. In other embodiments, based on the total weight of (a), (b), and (c), the biodegradable coating composition comprises 15% to 40% by weight, 17.5% to 40% by weight, or 20% to 40% by weight of inorganic filler.

[0019] Cellulose esters The cellulose ester is cellulose acetate propionate (CAP). The CAP has an average degree of substitution (DSOH) of 0.3 to 1.2 for hydroxyl substituents, an average degree of substitution (DSAC) of 0 to 0.5 for acetyl substituents, and an average degree of substitution (DSPr) of 1.8 to 2.7 for propionyl substituents. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the CAP has an average degree of substitution (DSOH) of 0.3 to 1.1, 0.4 to 1.1, or 0.5 to 1.0 for hydroxyl substituents, an average degree of substitution (DSAC) of 0 to 0.4, 0 to 0.3, 0 to 0.25, or 0 to 0.2 for acetyl substituents, and an average degree of substitution (DSPr) of 1.9 to 2.6 or 2.0 to 2.5 for propionyl substituents. In other embodiments, the average degree of substitution of the hydroxyl substituent in the CAP is 0.5 to 1.0, the average degree of substitution of the acetyl substituent (DSAc) is 0 to 0.2, and the average degree of substitution of the propionyl substituent (DSPr) is 2.0 to 2.5.

[0020] For cellulose esters, the level of substitution is typically expressed as the degree of substitution (“DS”), which is the average number of non-OH substituents in each dehydrated glucose unit (“AGU”). Typically, conventional cellulose contains three substituted hydroxyl groups in each AGU unit. As used herein, the term “degree of substitution” or “DS” refers to the average number of substituents in each dehydrated glucose ring of the cellulose polymer, with a maximum degree of substitution of 3.0. Because DS is a statistical average, a value of 1 does not guarantee that each AGU has a single substituent. In some cases, unsubstituted dehydrated glucose units may be present, some may have two substituents, and some may have three, and typically the values ​​will be non-integer. Total DS is defined as the average number of all substituents in each dehydrated glucose unit. The degree of substitution per AGU can also refer to a specific substituent, such as, for example, hydroxyl (DSOH) or acetyl (DSAC).

[0021] In the embodiments described herein, the falling ball viscosity of the CAP, as measured according to ASTM D1343, is 0.05 to 30 seconds. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the falling ball viscosity of the CAP, as measured according to ASTM D1343, may be 0.05 to 10, 0.05 to 5, 0.05 to 2, or 0.1 to 2 seconds. In other embodiments, the falling ball viscosity of the CAP, as measured according to ASTM D1343, may be 0.1 to 5 seconds.

[0022] In one or more embodiments herein, the average degree of substitution of hydroxyl substituents (DSOH) for CAP is 0.3 to 1.2, the average degree of substitution of acetyl substituents (DSAC) is 0 to 0.5, the average degree of substitution of propionyl substituents (DSPr) is 1.8 to 2.7, and the falling ball viscosity, as measured according to ASTM D1343, is 0.05 to 30 seconds. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the average degree of substitution of hydroxyl substituents (DSOH) in the CAP is 0.3 to 1.1, 0.4 to 1.1, or 0.5 to 1.0; the average degree of substitution of acetyl substituents (DSAC) is 0 to 0.4, 0 to 0.3, 0 to 0.25, or 0 to 0.2; the average degree of substitution of propionyl substituents (DSPr) is 1.9 to 2.6 or 2.0 to 2.5; and the falling ball viscosity, measured according to ASTM D1343, is 0.05 to 10, 0.05 to 5, 0.05 to 2, or 0.1 to 2 seconds. In other embodiments, the average degree of substitution of hydroxyl substituents in the CAP is 0.5 to 1.0; the average degree of substitution of acetyl substituents (DSAc) is 0 to 0.2; the average degree of substitution of propionyl substituents (DSPr) is 2.0 to 2.5; and the falling ball viscosity, measured according to ASTM D1343, is 0.1 to 5 seconds.

[0023] Biodegradable polymers In the embodiments described herein, the biodegradable polymer is a polyester. The polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), derivatives thereof, and combinations thereof. In some embodiments, the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), poly(butylene terephthalate adipate) (PBAT), derivatives thereof, and combinations thereof. In other embodiments, the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), derivatives thereof, and combinations thereof. In another embodiment, the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), and combinations thereof. In even further embodiments, the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), poly(butylene terephthalate adipate) (PBAT), and combinations thereof.

[0024] Inorganic packing Examples of suitable inorganic fillers may include calcium carbonate, titanium dioxide, alumina, silica, aluminosilicate, diatomaceous earth, magnesium oxide, talc, mica, zinc oxide, clay, barium sulfate, and mixtures thereof. In some embodiments herein, the inorganic filler is calcium carbonate, titanium dioxide, mica, or mixtures thereof. In other embodiments, the inorganic filler is calcium carbonate.

[0025] In embodiments herein, the biodegradable coating composition has a glass transition temperature (Tg) of -40 to -10°C, a melting temperature (Tm) of 80 to 110°C, and a crystallization temperature (Tc) of 40 to 70°C. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the biodegradable coating composition has a glass transition temperature (Tg) of -40 to -10°C, -35 to -15°C, -30 to -15°C, or -30 to -20°C; a melting temperature (Tm) of 80 to 110°C, 85 to 110°C, 90 to 105°C, or 92.5 to 102.5°C; and a crystallization temperature (Tc) of 40 to 70°C, 40 to 65°C, 40 to 60°C, or 42.5 to 58°C.

[0026] In the embodiments described herein, the biodegradable coating composition has a Young's modulus greater than 700 MPa, an elongation at break of 10% to 300%, and a water vapor transmission rate (WVTR) less than 600 g·mil / (m²). 2 • Days). All individual values ​​and subranges are included and disclosed herein. For example, in some embodiments, the biodegradable coating composition has a Young's modulus greater than 700 MPa, greater than 800 MPa, greater than 900 MPa, or greater than 1,000 MPa; an elongation at break of 10% to 300%, 10% to 275%, or 10% to 250%; and a water vapor transmission rate (WVTR) of less than 600 g·mil / (m 2 ·day), 400 to 600g·mil / (m 2 (day) or 400 to 585 g·mil / (m 2 ·sky).

[0027] In one or more embodiments herein, the viscosity (V200) of the biodegradable coating composition at 200°C and 10 rad / s may be 500 to 800 Pa·s, and the viscosity ratio (V65 / V200) may be less than 28, wherein V65 is the viscosity measured at 65°C and 10 rad / s. All individual values ​​and subranges are included herein and disclosed herein. For example, in some embodiments, the viscosity (V200) of the biodegradable coating composition at 200°C and 10 rad / s may be 500 to 800 Pa·s or 500 to 750 Pa·s, and the viscosity ratio (V65 / V200) may be less than 28 or may be 10 to 28, wherein V65 is the viscosity measured at 65°C and 10 rad / s. Unbound by theory, it is believed that viscosity and viscosity ratio (V65 / V200) parameters indicate extrusion coating speed and paper adhesion, such that a certain viscosity range at 200°C (i.e., the range to be protected) indicates a higher coating speed, while a certain viscosity ratio V65 / V200 range (i.e., the range to be protected) indicates better paper adhesion without any cold roll sticking problems.

[0028] The embodiments described herein also disclose a method for manufacturing a biodegradable coated paper article. The method includes: providing a paper substrate; and extruding a layer onto the paper substrate to form a biodegradable coated paper article, wherein the layer is formed from a biodegradable coating composition as previously described herein. In some embodiments, the layer is a single layer formed on the paper substrate. In other embodiments, the layer is a multilayer (i.e., two or more layers) formed on the paper substrate. In still other embodiments, the layer is a multilayer formed on the paper substrate, wherein at least one of the multilayers is formed from a biodegradable coating composition as previously described herein.

[0029] Test methods Viscosity Viscosities were measured using a TA Instruments ARES-G2. Samples were dried in a vacuum oven at 60°C for two days prior to viscosity measurement. Temperature sweeps were determined by measuring the viscosity from 230°C to 50°C at 10 rad / sec. The heating rate was 5°C / min, the sampling interval was 10 seconds, and the strain rate was 10%. Results are reported in Pa·s.

[0030] Differential scanning calorimetry (DSC) The thermal transition of the artificial turf infill coating composition was measured by differential scanning calorimetry (DSC) using a DSC instrument (Q 2000, TA Instruments, New Castle, DE, USA). For analysis, 4 to 8 mg of each sample was sealed in an aluminum DSC pan and evaluated using a “heat-cool-heat” method. For the first heating, the sample was evaluated from -80°C to 250°C at a scan rate of 20°C / min. Next, the sample was cooled from 250°C to -80°C at a scan rate of 20°C / min, and the midpoint transition value was labeled “Tc”. Finally, the sample was reheated from -80°C to 250°C at a scan rate of 20°C / min, and the midpoint transition values ​​were labeled Tg and Tm. Tg is the glass transition temperature, Tm is the melting point, and Tc is the crystallization temperature. Values ​​are reported in degrees Celsius (°C).

[0031] Tensile properties Tensile properties were tested using the ASTM D638-V method. Samples were compressed into 500 µm films at 200°C. Young's modulus is reported in MPa, and elongation at break is reported as a percentage (%).

[0032] Water vapor transmission rate (WVTR) WVTR was measured according to ASTM F1249. Samples were pressure-molded into 250 µm films at 200°C. WVTR is expressed as g·mil / (m 2 (Tian) report.

[0033] Nuclear magnetic resonance (NMR) 20 mg of sample was dissolved in 1 mL of deuterated dimethyl sulfoxide at 80 °C. 85 µL of trifluoroacetic acid-d / tetramethylsilane (TFA-d / TMS) solution was added to the vial and slowly rotated. The solution was then transferred to a 5 mm NMR tube. Proton NMR data were acquired on a Bruker Avance III 600 MHz spectrometer. Each spectrum was processed using ACD-Spectrus Processor software.

[0034] Falling ball viscosity Falling ball viscosity was measured according to ASTM D1343. Results are reported in seconds.

[0035] Example The following specific examples illustrate the process and performance characteristics related to biodegradable coated paper products and their components. Examples and comparative examples of the invention are provided below, with details of formulations and results provided in the tables below.

[0036] Table 1 – Raw Materials Table 2 – Properties of CAP Resin The biodegradable coating compositions were formulated according to the following procedure: formulations were compounded and granules were produced using an 18 mm Leistritz twin-screw extruder and a single-hole die. All resins were dried at 60–80°C for at least 4 hours. All formulations were compounded at 180–230°C under non-vacuum conditions. Formulation details are shown in Table 3 below.

[0037] Table 3 – Biodegradable Coating Compositions Various properties and characteristics of the examples were analyzed, and the results are shown in Table 4-7.

[0038] Table 4 – DSC Values Table 5 – Viscosity Table 6 – Tensile Properties Table 7 – Water Vapor Transmission Rate (WVTR) Other formulation examples were generated using the same procedure as in Examples 1-19 above. Formulation details and DSC analysis results are shown in Table 8 below.

[0039] Table 8 - Biodegradable coating compositions and DSC The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​stated. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and a functionally equivalent range around that value. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0040] Unless expressly excluded or otherwise limited, every reference cited herein (if any), including any cross-referenced or related patent or application and any patent application or patent claiming priority or benefit to this application, is hereby incorporated in its entirety by reference. Reference to any document does not imply that it is prior art relating to any invention disclosed or claimed herein, or that it, alone or in any combination with any other reference, teaches, suggests, or discloses any such invention. Furthermore, where any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a referenced document, the meaning or definition given to that term in this document shall prevail.

[0041] While specific embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all such changes and modifications that fall within the scope of the invention.

Claims

1. A biodegradable coated paper article, the article comprising a paper substrate and a layer disposed on the paper substrate, wherein the layer is formed of a biodegradable coating composition, the biodegradable coating composition comprising: a. A cellulose ester, wherein the cellulose ester is cellulose acetate propionate (CAP), and the amount thereof is 5.5 to 15% by weight based on the total weight of (a), (b) and (c); b. A biodegradable polymer, said biodegradable polymer being a polyester, wherein the amount thereof is 45 to 75% by weight based on the total weight of (a), (b) and (c); and c. Inorganic filler, the amount of which is 12 to 40% by weight based on the total weight of (a), (b) and (c); The polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), its derivatives, and combinations thereof. The CAP has an average degree of substitution (DSOH) of 0.3 to 1.2 for hydroxyl substituents, an average degree of substitution (DSAc) of 0 to 0.5 for acetyl substituents, an average degree of substitution (DSPr) of 1.8 to 2.7 for propionyl substituents, and a falling ball viscosity of 0.05 to 30 seconds as measured according to ASTM D-1343. The biodegradable coating composition has a glass transition temperature (Tg) of -40 to -10°C, a melting temperature (Tm) of 80 to 110°C, and a crystallization temperature (Tc) of 40 to 70°C. The biodegradable coating composition described herein has a Young's modulus greater than 700 MPa, an elongation at break of 10% to 300%, and a water vapor transmission rate (WVTR) of less than 600 g·mil / (m²). 2 ·sky).

2. The biodegradable coated paper product according to claim 1, wherein the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate) (PBSA), poly(butylene terephthalate) (PBAT), derivatives thereof, and combinations thereof.

3. The biodegradable coated paper product according to claim 1 or 2, wherein the inorganic filler is calcium carbonate.

4. The biodegradable coated paper product according to claims 1-3, wherein the amount of the inorganic filler is 20 to 40% by weight of the biodegradable coating composition.

5. The biodegradable coated paper product according to claims 1-4, wherein the average degree of substitution of the CAP is 0.5 to 1.0 for hydroxyl substituents, 0 to 0.2 for acetyl substituents (DSAc), 2.0 to 2.5 for propionyl substituents (DSPr), and the falling ball viscosity is 0.1 to 5 seconds as measured according to ASTM D-1343.

6. The biodegradable coated paper product according to claims 1-5, wherein the crystallization temperature (Tc) of the biodegradable coating composition is 40 to 60°C.

7. The biodegradable coated paper product according to claims 1-6, wherein the biodegradable coating composition has a viscosity (V200) of 500 to 800 Pa·s at 200°C and 10 rad / s, and a viscosity ratio (V65 / V200) of less than 28, wherein V65 is the viscosity measured at 65°C and 10 rad / s.

8. The biodegradable coated paper article according to claims 1-7, wherein the paper substrate has a weight of 50 gsm to 350 gsm.

9. A method for manufacturing biodegradable coated paper products, the method comprising: Provide paper substrates; The layers are extruded and coated onto the paper substrate to form a biodegradable coated paper product. The layer is formed from a biodegradable coating composition comprising: a. A cellulose ester, wherein the cellulose ester is cellulose acetate propionate (CAP), and the amount thereof is 5.5 to 15% by weight based on the total weight of (a), (b) and (c); b. A biodegradable polymer, said biodegradable polymer being a polyester, wherein the amount thereof is 45 to 75% by weight based on the total weight of (a), (b) and (c); and c. Inorganic filler, the amount of which is 12 to 40% by weight based on the total weight of (a), (b) and (c); The polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), polycaprolactone (PCL), poly(butylene terephthalate adipate) (PBAT), polylactic acid (PLA), its derivatives, and combinations thereof. The CAP has an average degree of substitution (DSOH) of 0.3 to 1.2 for hydroxyl substituents, an average degree of substitution (DSAc) of 0 to 0.5 for acetyl substituents, an average degree of substitution (DSPr) of 1.8 to 2.7 for propionyl substituents, and a falling ball viscosity of 0.05 to 30 seconds as measured according to ASTM D-1343. The biodegradable coating composition has a glass transition temperature (Tg) of -40 to -10°C, a melting temperature (Tm) of 80 to 110°C, and a crystallization temperature (Tc) of 40 to 70°C. The biodegradable coating composition described herein has a Young's modulus greater than 700 MPa, an elongation at break of 10% to 300%, and a water vapor transmission rate (WVTR) of less than 600 g·mil / (m²). 2 ·sky).

10. The method of claim 9, wherein the polyester is selected from poly(butylene succinate) (PBS), poly(butylene adipate succinate) (PBSA), poly(butylene terephthalate adipate) (PBAT), derivatives thereof, and combinations thereof.

11. The method according to claim 9 or 10, wherein the inorganic filler is calcium carbonate.

12. The method according to claims 9-11, wherein the amount of the inorganic filler is 20 to 40% by weight of the biodegradable coating composition.

13. The method according to claims 9-12, wherein the average degree of substitution of the hydroxyl substituents in the CAP is 0.5 to 1.0, the average degree of substitution of the acetyl substituents (DSAc) is 0 to 0.2, the average degree of substitution of the propionyl substituents (DSPr) is 2.0 to 2.5, and the falling ball viscosity measured according to ASTM D-1343 is 0.1 to 5 seconds.

14. The method according to claims 9-13, wherein the crystallization temperature (Tc) of the biodegradable coating composition is 40 to 60°C.

15. The method according to claims 9-14, wherein the biodegradable coating composition has a viscosity (V200) of 500 to 800 Pa·s at 200°C and 10 rad / s, and a viscosity ratio (V65 / V200) of less than 28, wherein V65 is the viscosity measured at 65°C and 10 rad / s.

16. The method according to claims 9-15, wherein the weight of the paper substrate is from 50 gsm to 350 gsm.

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