Degradable full-biological-base food coating paper, preparation method and application thereof

Abstract

The application belongs to the technical field of coated paper and specifically discloses a food degradable full-biological-based coated paper, a preparation method and application; the food degradable full-biological-based coated paper is composed of a coated paper special for coating and a biodegradable film; the preparation raw material of the biodegradable film comprises, in terms of weight parts, PLA: 60-70 parts, PHA: 30-40 parts, a compatibilizer: 1-3 parts, an antioxidant: 0.1-1 part, a lubricant: 0.2-0.5, and a chain extender: 0.1-0.5 part; wherein the PLA is polylactic acid, the molecular weight of the PLA is 4000-5000, the melting point of the PLA is 150-165 DEG C, and the melt flow index of the PLA is 25-35 g / 10 min; the PHA is a copolymer of hydroxyhexanoate and 3-hydroxybutyric acid ester, and the molecular weight of the PHA is 1000-8000. In the preparation of the coated paper, the compatibilizer PLA-g-GMA is added to the preparation raw material, the PLA and the PHA can be effectively combined through the compatibilizer, the prepared food degradable full-biological-based coated paper not only has a biodegradation capacity and is beneficial to environmental protection, but also has good toughness and is not easy to be damaged in use.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laminated paper, and particularly relates to a degradable full-biobased laminated paper for food, a preparation method and application. BACKGROUND

[0002] Laminated paper is a composite material in which plastic particles are coated on the surface of paper by a flow coater, and the main feature is that it can prevent oil and water (relatively), and can be heat sealed. At present, laminated paper made of polyethylene (PE) is commonly used to make disposable paper cups, paper bowls and other disposable tableware, but the laminated paper made of polyethylene cannot be biodegraded, which is not conducive to environmental protection.

[0003] Polylactic acid (PLA) is a new type of biobased and renewable biodegradable material, which is made of starch raw materials extracted from renewable plant resources (such as corn, cassava, etc.). The starch raw material is saccharified to obtain glucose, and then the glucose and certain strains are fermented to prepare high-purity lactic acid, and then a certain molecular weight of polylactic acid is synthesized by chemical synthesis method. It has good biodegradability, can be completely degraded by microorganisms in nature under certain conditions after use, and finally generates carbon dioxide and water, which has no pollution to the environment, and is recognized as an environmentally friendly material. The PLA laminated paper made of PLA laminating can greatly reduce the burden on natural resources and the environment compared with the disposable tableware made of PE laminated paper, and is favored by consumers. However, PLA has high brittleness, and when it is directly used to process laminated paper, the stability is poor, and the toughness of the laminated layer after forming is not enough, which is easy to break, and is not conducive to the wide application of PLA laminated paper.

[0004] Polyhydroxyalkanoate (PHA) is an intracellular polyester synthesized by many bacteria, which mainly exists in the body as a carbon source and energy storage material, and has many excellent properties such as biodegradability, biocompatibility, optical activity, piezoelectricity, gas barrier property and other properties similar to synthetic plastics. In addition, because the molecular structure of PHA has a long aliphatic chain, its toughness is better than that of polylactic acid.

[0005] Therefore, we combine PHA with PLA and propose a degradable full-biobased laminated paper for food, a preparation method and application. SUMMARY

[0006] In view of the shortcomings of the prior art, the application provides a degradable full-biobased laminated paper for food, a preparation method and application.

[0007] The object of the application can be achieved by the following technical scheme:

[0008] The application discloses a food degradable full-bio-based laminated film paper, which is composed of a laminated film special paper and a biodegradable film.

[0009] PLA: 60-70 parts,

[0010] PHA: 30-40 parts,

[0011] compatibility agent: 1-3 parts,

[0012] antioxidant: 0.1-1 part,

[0013] lubricant: 0.2-0.5,

[0014] chain extender: 0.1-0.5 parts.

[0015] The PLA is polylactic acid, the molecular weight of the PLA is 4000-5000, the melting point of the PLA is 150-165 DEG C, and the melt flow index of the PLA is 25-35 g / 10 min.

[0016] The PHA is a copolymer of hydroxyhexanoate and 3-hydroxybutyric acid, and the molecular weight of the PHA is 1000-8000.

[0017] Preferably, full-wood pulp is used as the preparation raw material of the laminated film special paper.

[0018] Preferably, the compatibility agent is PLA-g-GMA, specifically polylactic acid grafted glycidyl methacrylate.

[0019] Preferably, the lubricant is pentaerythritol stearate.

[0020] Preferably, the antioxidant is at least one of antioxidant 1010 or antioxidant 1076.

[0021] Preferably, the chain extender is one or more of sodium benzoate, p-tert-butyl benzoic acid and vitamin B13.

[0022] Preferably, a preparation method of the food degradable full-bio-based laminated film paper comprises the following steps.

[0023] S1, dry preparation raw materials PLA, PHA, compatibility agent, antioxidant and chain extender are uniformly mixed to obtain a mixture;

[0024] S2, the mixture is added into an extruder to be melted, extruded and granulated to obtain a laminated film paper biodegradable special resin.

[0025] S3, after drying and dehumidifying the special resin for biodegradation of the coated paper, the special resin is added into a coating machine, coating is performed on the special paper for coating by using the coating machine, and after the coating is completed, the coated special paper for coating is dried to obtain the fully biobased coated paper for food which is degradable.

[0026] Preferably, the extruder in the step S2 is a double-screw extruder, the extrusion temperature is 80-165 DEG C, and the rotating speed is 180-210 rpm / min.

[0027] Preferably, in the step S3, the body temperature is 170-180 DEG C, and the die temperature is 180-190 DEG C; and the drying temperature in the step S3 is 25-30 DEG C, and the drying time is 4-6 hours.

[0028] Preferably, the fully biobased coated paper for food which is degradable is applied in the field of food packaging and the catering industry.

[0029] The beneficial effects of the present application are as follows:

[0030] 1. In the preparation of the coated paper, the compatible agent PLA-g-GMA is added in the preparation raw material, and the PLA and the PHA can be effectively combined through the compatible agent, so that the fully biobased coated paper for food which is degradable not only has the biodegradation ability and is beneficial to environmental protection, but also has good toughness and is not easy to be damaged in use.

[0031] 2. The fully biobased coated paper for food which is degradable prepared by the present application has good high-temperature resistance and good waterproof performance.

[0032] 3. The preparation method of the fully biobased coated paper for food which is degradable provided by the present application has no need for multiple production equipment, the process is simple, the production efficiency is high, and the method is beneficial to large-scale promotion. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0034] Figure 1 The physical map of the fully biobased coated paper for food which is degradable prepared by the embodiment 1 of the present application. DETAILED DESCRIPTION

[0035] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] Embodiment 1

[0037] S1, dry preparation raw materials PLA 60 parts, PHA 30 parts, compatibilizer PLA-g-GMA 1 part, antioxidant 1010 0.5 part, lubricant pentaerythritol stearate 0.2 part and chain extender sodium benzoate 0.5 part are mixed uniformly to obtain a mixture;

[0038] S2, the mixture is added to the double screw extruder to melt, extrude and granulate to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the double screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0039] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0040] It should be noted that the parts mentioned in embodiment 1 are 50g of material.

[0041] Embodiment 2

[0042] S1, dry preparation raw materials PLA 70 parts, PHA 30 parts, compatibilizer PLA-g-GMA 1 part, antioxidant 1010 0.5 part, lubricant pentaerythritol stearate 0.2 part and chain extender sodium benzoate 0.5 part are mixed uniformly to obtain a mixture;

[0043] S2, the mixture is added to the double screw extruder to melt, extrude and granulate to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the double screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0044] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0045] It should be noted here that the number of portions mentioned in Example 2 is 50 g of material.

[0046] Example 3

[0047] S1, 60 parts of the dried raw materials PLA, 40 parts of PHA, 1 part of the compatibilizer PLA-g-GMA, 0.5 parts of the antioxidant 1010, 0.2 parts of the lubricant pentaerythritol stearate, and 0.5 parts of the chain extender sodium benzoate were mixed to obtain a mixture;

[0048] S2. Add the mixture into a twin-screw extruder, melt, extrude, and granulate to obtain a biodegradable resin for coated paper; wherein the extrusion temperature of the twin-screw extruder is 150° C. and the rotation speed is 200 rpm / min;

[0049] S3. After drying and dehumidifying the biodegradable resin for laminated paper, add it into the laminating machine, and use the laminating machine to laminate the laminated paper. After the laminating is completed, place the laminated paper in a drying oven and dry it at 30°C for 5 hours to obtain biodegradable fully bio-based laminated paper for food. During the laminating process, the body temperature of the laminating machine is 170-180°C, and the die head temperature is 180-190°C.

[0050] It should be noted here that the number of portions mentioned in Example 3 is 50 g of material.

[0051] Example 4

[0052] S1, 70 parts of the dried raw materials PLA, 40 parts of PHA, 1 part of the compatibilizer PLA-g-GMA, 0.5 parts of the antioxidant 1010, 0.2 parts of the lubricant pentaerythritol stearate, and 0.5 parts of the chain extender sodium benzoate were mixed to obtain a mixture;

[0053] S2. Add the mixture into a twin-screw extruder, melt, extrude, and granulate to obtain a biodegradable resin for coated paper; wherein the extrusion temperature of the twin-screw extruder is 150° C. and the rotation speed is 200 rpm / min;

[0054] S3. After drying and dehumidifying the biodegradable resin for laminated paper, add it into the laminating machine, and use the laminating machine to laminate the laminated paper. After the laminating is completed, place the laminated paper in a drying oven and dry it at 30°C for 5 hours to obtain biodegradable fully bio-based laminated paper for food. During the laminating process, the body temperature of the laminating machine is 170-180°C, and the die head temperature is 180-190°C.

[0055] It should be noted here that the number of portions mentioned in Example 4 is 50 g of material.

[0056] Example 5

[0057] S1, dry preparation raw material PLA 60 parts, PHA 40 parts, compatibilizer PLA-g-GMA 3 parts, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts were mixed uniformly to obtain a mixture;

[0058] S2, the mixture was added to the twin-screw extruder and melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder was 150°C, and the rotation speed was 200 rpm / min;

[0059] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it was added to the laminating machine, and the laminating machine was used to laminate the special paper for laminating. After the lamination was completed, the laminated special paper for laminating was placed in a drying oven and dried at 30°C for 5 hours to obtain a fully biobased laminated paper for food use. The body temperature of the laminating machine during the lamination process was 170-180°C, and the die temperature was 180-190°C.

[0060] It should be noted here that the parts mentioned in Example 5 are 50g of material.

[0061] Example 6

[0062] S1, dry preparation raw material PLA 70 parts, PHA 40 parts, compatibilizer PLA-g-GMA 3 parts, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts were mixed uniformly to obtain a mixture;

[0063] S2, the mixture was added to the twin-screw extruder and melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder was 150°C, and the rotation speed was 200 rpm / min;

[0064] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it was added to the laminating machine, and the laminating machine was used to laminate the special paper for laminating. After the lamination was completed, the laminated special paper for laminating was placed in a drying oven and dried at 30°C for 5 hours to obtain a fully biobased laminated paper for food use. The body temperature of the laminating machine during the lamination process was 170-180°C, and the die temperature was 180-190°C.

[0065] It should be noted here that the parts mentioned in Example 6 are 50g of material.

[0066] Comparative Example 1

[0067] S1, dry preparation of raw materials PLA 40 parts, PHA 30 parts, compatible agent PLA-g-GMA 1 part, antioxidant 101 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0068] S2, the mixture is added to the twin-screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0069] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0070] It should be noted here that the parts mentioned in Comparative Example 1 are 50g of material.

[0071] Comparative Example 2

[0072] S1, dry preparation of raw materials PLA 40 parts, PHA 30 parts, compatible agent PLA-g-GMA 1 part, antioxidant 101 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0073] S2, the mixture is added to the twin-screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0074] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0075] It should be noted here that the parts mentioned in Comparative Example 2 are 50g of material.

[0076] Comparative Example 3

[0077] S1, dry preparation of raw materials PLA 60 parts, PHA 20 parts, 1 part of compatible agent PLA-g-GMA, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0078] S2, the mixture is added to the twin-screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0079] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0080] It should be noted here that the parts mentioned in Comparative Example 3 are 50g of material.

[0081] Comparative Example 4

[0082] S1, dry preparation of raw materials PLA 60 parts, PHA 20 parts, 1 part of compatible agent PLA-g-GMA, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0083] S2, the mixture is added to the twin-screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0084] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to the laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the lamination is completed, the laminated special paper for laminating is placed in a drying box and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the lamination process is 170-180℃, and the die temperature is 180-190℃.

[0085] It should be noted here that the parts mentioned in Comparative Example 4 are 50g of material.

[0086] Comparative Example 5

[0087] S1, dry preparation of raw materials PLA 60 parts, PHA 30 parts, compatibilizer PLA-g-GMA 0.5 parts, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0088] S2, the mixture is added to the twin screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0089] S3, the special resin for biodegradable laminated paper is dried and dehumidified, then added to the laminating machine, and laminated on the special laminated paper using the laminating machine. After the lamination is completed, the laminated special laminated paper is placed in a drying oven and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during lamination is 170-180℃, and the die temperature is 180-190℃.

[0090] It should be noted here that the parts mentioned in Comparative Example 5 are 50g of material.

[0091] Comparative Example 6

[0092] S1, dry preparation of raw materials PLA 60 parts, PHA 30 parts, compatibilizer PLA-g-GMA 5 parts, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0093] S2, the mixture is added to the twin screw extruder, melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin screw extruder is 150℃, and the rotating speed is 200rpm / min;

[0094] S3, the special resin for biodegradable laminated paper is dried and dehumidified, then added to the laminating machine, and laminated on the special laminated paper using the laminating machine. After the lamination is completed, the laminated special laminated paper is placed in a drying oven and dried at 30℃ for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during lamination is 170-180℃, and the die temperature is 180-190℃.

[0095] It should be noted here that the parts mentioned in Comparative Example 6 are 50g of material.

[0096] Comparative Example 7

[0097] S1, dry preparation of raw materials PLA 60 parts, PHA 30 parts, compatible agent PLA-g-GMA 0 parts, antioxidant 1010 0.5 parts, lubricant pentaerythritol stearate 0.2 parts and chain extender sodium benzoate 0.5 parts are mixed uniformly to obtain a mixture;

[0098] S2, the mixture is added to the twin-screw extruder and melted, extruded and granulated to obtain a special resin for biodegradable laminated paper; wherein the extrusion temperature of the twin-screw extruder is 150°C, and the rotation speed is 200 rpm / min;

[0099] S3, after drying and dehumidifying the special resin for biodegradable laminated paper, it is added to a laminating machine, and the laminating machine is used to laminate the special paper for laminating. After the laminating is completed, the laminated special paper for laminating is placed in a drying box and dried at 30°C for 5 hours to obtain a fully biobased degradable laminated paper for food; the body temperature of the laminating machine during the laminating process is 170-180°C, and the die temperature is 180-190°C.

[0100] It should be noted here that the parts mentioned in Comparative Example 7 are 50g of material.

[0101] The laminated paper prepared in Examples 1-6 and Comparative Examples 1-7 is subjected to performance detection, and the high temperature resistance, tensile strength, breaking performance and waterproof performance of the laminated paper are measured respectively; the measurement results are shown in Table 3.

[0102] High temperature resistance measurement: mainly measures the critical temperature value at which the laminated paper softens;

[0103] Tensile strength measurement: refer to GB / T104Q-2006: Plastic tensile property test method.

[0104] Breaking performance measurement: refer to the test method for resin casting body performance in GB / T 2567-2008.

[0105] Waterproof performance measurement: water test is carried out on the laminated paper prepared in Examples 1-6 and Comparative Examples 1-7 respectively.

[0106]

[0107]

[0108] Table 3 is the performance detection result data of the laminated paper prepared in Examples 1-6 and Comparative Examples 1-7

[0109] ​In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0110] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A biodegradable fully bio-based coated paper for food, characterized in that: The biodegradable fully bio-based coated paper for food is composited with coated special paper and biodegradable film. The raw materials for preparing the biodegradable film include, by weight: PLA: 60-70 parts, PHA: 30-40 parts, Compatibilizer: 1-3 parts, Antioxidant: 0.1-1 parts, Lubricant: 0.2-0.5, Chain extender: 0.1-0.5 parts; Among them, PLA is polylactic acid, with a molecular weight of 4000-5000, a melting point of 150-165°C, and a melt flow index of 25-35g / 10min; PHA is a copolymer of hydroxycaproate and 3-hydroxybutyrate, and the molecular weight of the PHA is 1000-8000; The compatibilizer is PLA-g-GMA, specifically polylactic acid grafted with glycidyl methacrylate.

2. The biodegradable fully bio-based coated paper for food according to claim 1, characterized in that: The raw material for preparing the special laminating paper is whole wood pulp.

3. The biodegradable fully bio-based coated paper for food according to claim 1, characterized in that: The lubricant is pentaerythritol stearate.

4. The biodegradable fully bio-based coated paper for food according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant 1076.

5. The biodegradable fully bio-based coated paper for food according to claim 1, characterized in that: The chain extender is one or more of sodium benzoate, p-tert-butylbenzoic acid, and vitamin B13.

6. A method for preparing the biodegradable fully bio-based coated paper for food according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: S1. Mixing the dried raw materials PLA, PHA, a compatibilizer, an antioxidant, a lubricant, and a chain extender to obtain a mixture; S2, adding the mixture into an extruder, melting, extruding, and granulating to obtain a biodegradable resin for laminated paper; S3. After drying and dehumidifying the biodegradable resin for laminated paper, add it into a laminating machine, and use the laminating machine to laminate the laminated paper. After laminating, dry the laminated paper to obtain biodegradable fully bio-based laminated paper for food.

7. The preparation method according to claim 6, characterized in that In step S2, the extruder is a twin-screw extruder with an extrusion temperature of 80-165° C. and a rotation speed of 180-210 rpm / min.

8. The preparation method according to claim 6, characterized in that During the laminating process in step S3, the machine body temperature is 170-180°C, and the die head temperature is 180-190°C. The drying temperature in step S3 is 25-30°C, and the drying time is 4-6 hours.

9. Application of the biodegradable fully bio-based coated paper for food according to any one of claims 1 to 5 in the field of food packaging and the catering industry.

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