A biodegradable film paper and a method for preparing the same

Abstract

The application discloses a biodegradable film paper and a preparation method thereof. The film paper comprises a base paper, an oil-proof layer arranged on the base paper and a water-proof layer arranged on the oil-proof layer. The oil-proof layer is formed by coating an oil-proof glue solution and drying the oil-proof glue solution. The oil-proof glue solution is prepared from a film forming agent, a cellulose derivative, deionized water and glycerol. The water-proof layer is formed by coating a water-proof glue solution and drying the water-proof glue solution. The water-proof glue solution is prepared by mixing polylactic acid and dichloromethane or by mixing polyvinyl butyral and anhydrous ethanol. The water-proof layer and the oil-proof layer have good adhesion and good barrier properties to hot water or hot oil. No leakage occurs on the paper after 30 minutes of testing under the condition of 95±5 DEG C hot water or 125±5 DEG C hot oil.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of degradable high polymer materials, and particularly relates to a biodegradable film paper and a preparation method thereof. BACKGROUND

[0002] In order to reduce the use of plastic packaging, people turn their attention to degradable paper packaging. Paper packaging is a kind of green and environmentally friendly packaging material, which is mainly applied to food packaging and industrial product packaging. However, due to the porous network structure of cellulose in the paper used in paper packaging, the barrier property of paper material to liquid (such as water and oil) is not ideal, so it is still necessary to spray a layer of plastic film (laminated film) on the surface of the paper. At present, the market still mainly uses non-degradable polyethylene (PE) or polypropylene (PP) as the laminated film material, and these laminated film materials are difficult to recycle and are also harmful to the environment. Therefore, using biodegradable materials, especially biologically derived materials, as laminated film materials will be an effective solution to promote the environmental protection of paper packaging materials.

[0003] CN110777566A discloses a degradable waterproof and oil-proof coating prepared from modified chitosan, montmorillonite and fluorosilicon organic matter, and the barrier property is very close to that of common packaging paper on the market, but the barrier property to hot water needs to be improved, the fluorosilicon organic matter used may affect human health, and the solvent used is acetic acid, which may produce a pungent smell and affect the sensory experience; CN116556101A discloses a waterproof and oil-proof paper pulp molding prepared from chitosan and stearic acid, which has very strong waterproof and oil-proof effects on hot water and hot oil at 95±5℃, but the adhesive property of the waterproof layer is prone to be affected by external force and needs to be improved; CN114990936A discloses a waterproof and oil-proof paper prepared from sodium alginate, chitosan, nanoparticles and biological wax, which has good oil-proof property (oil-proof grade 12) and waterproof property (Cobb value = 9.5 g / m 2 ). SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide a biodegradable film paper.

[0005] Still another object of the present application is to provide a preparation method of the biodegradable film paper.

[0006] The technical solution of the present application is as follows:

[0007] A biodegradable film paper, comprising a base paper, an oil-proof layer arranged on the base paper, and a waterproof layer arranged on the oil-proof layer, wherein,

[0008] The oil-proof layer is formed by coating and drying an oil-proof glue solution, which is prepared by a film-forming agent, a cellulose derivative, deionized water and glycerol; the film-forming agent is gellan gum, kappa-carrageenan or iota-carrageenan, and the cellulose derivative is hydroxypropyl methyl cellulose or sodium carboxymethyl cellulose;

[0009] The waterproof layer is formed by coating and drying a waterproof glue solution, which is prepared by mixing polylactic acid and dichloromethane, or by mixing polyvinyl butyral and anhydrous ethanol.

[0010] In a preferred embodiment of the present application, the oil-proof glue solution is prepared by the film-forming agent, the cellulose derivative, deionized water and glycerol in a mass ratio of 0.4-1.6:0.4-1.6:96.5-97.5:0.5-1.5.

[0011] Further preferably, the oil-proof glue solution is prepared by kappa-carrageenan, hydroxypropyl methyl cellulose, deionized water and glycerol in a mass ratio of 0.8-1.2:0.8-1.2:97:1.

[0012] In a preferred embodiment of the present application, the waterproof glue solution is prepared by mixing polylactic acid and dichloromethane in a mass ratio of 5-10:90-95, or by mixing polyvinyl butyral and anhydrous ethanol in a mass ratio of 5-10:90-95.

[0013] In a preferred embodiment of the present application, the coating amount of the oil-proof glue solution is 3-6 g / m 2 , and the coating amount of the waterproof glue solution is 5-10 g / m 2 .

[0014] The preparation method of the biodegradable film paper comprises the following steps:

[0015] (1) heating and stirring the film-forming agent, the cellulose derivative and deionized water until uniform, then adding glycerol, continuing to stir until uniform, and then standing to remove bubbles to obtain an oil-proof glue solution;

[0016] (2) mixing and stirring polylactic acid and dichloromethane until uniform, or mixing and stirring polyvinyl butyral and anhydrous ethanol until uniform, and then standing to remove bubbles to obtain a waterproof glue solution;

[0017] (3) coating the oil-proof glue solution on one side of the base paper, and drying to obtain a single-layer oil-proof paper with an oil-proof layer;

[0018] (4) coating the waterproof glue solution on the oil-proof layer obtained in step (3), and drying to obtain the biodegradable film paper.

[0019] In a preferred embodiment of the present application, in step (1), the temperature for stirring is 60-70℃, and the temperature for standing to remove bubbles is 60-70℃.

[0020] In a preferred embodiment of the present application, in the step (2), the temperature of stirring is 20-25℃, and the temperature of standing for defoaming is 20-25℃.

[0021] In a preferred embodiment of the present application, in the step (3), the coating speed is 15-20mm / s, and the drying temperature is 50-70℃.

[0022] In a preferred embodiment of the present application, in the step (4), the coating speed is 15-20mm / s, and the drying temperature is 20-25℃.

[0023] The present application has the following beneficial effects:

[0024] 1. The waterproof layer and the oil-proof layer of the present application have good adhesion, and have good barrier performance to hot water or hot oil, and the paper does not leak after being tested in 95±5℃ hot water or 125±5℃ hot oil for 30min.

[0025] 2. The preparation method of the present application has simple process and low cost, and is suitable for industrial production. DETAILED DESCRIPTION

[0026] The technical solutions of the present application are further described and explained through specific embodiments.

[0027] Example 1

[0028] (1) Preparation of oil-proof glue solution (by mass fraction): 1 part of K-carrageenan and 1 part of hydroxypropyl methyl cellulose are added to a container containing 97 parts of deionized water, and stirred at a temperature of 60℃ for 2h to obtain an oil-proof glue solution; 1 part of glycerol is added, and then stirring is continued at a temperature of 60℃ for 1h, and the stirring is stopped; the oil-proof glue solution is placed at a temperature of 60℃ for standing for defoaming, and the standing time for defoaming is 2h;

[0029] (2) Preparation of waterproof glue solution (by mass fraction): 5 parts of polylactic acid are added to a container containing 95 parts of dichloromethane, and stirred at a temperature of 25℃ for 1.5h, and then the stirring is stopped, and the container is placed at a temperature of 25℃ for standing for defoaming for 0.5h to obtain a waterproof glue solution;

[0030] (3) First coating: the oil-proof coating glue solution in step (1) is coated on one side of the base paper using a coating machine, and after coating, the paper is placed in a drying box for drying, and after drying, a single-layer oil-proof paper with an oil-proof layer is obtained, the coating amount is 5g / m 2 , the coating speed is 15mm / s, the drying temperature is 50℃, and the drying time is 0.5h;

[0031] (4) Second coating: The waterproof coating adhesive from step (2) is applied to the single-layer oil-proof paper from step (3) using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a biodegradable film paper is obtained with a coating amount of 10 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 25℃, and the drying time is 1 hour.

[0032] Example 2

[0033] (1) Preparation of oil-resistant adhesive (by mass): 1 part 1-carrageenan and 1 part hydroxypropyl methylcellulose were added to a container containing 97 parts deionized water and stirred at 60°C for 2 hours to obtain the oil-resistant adhesive; 1 part glycerin was added and stirred at 60°C for 1 hour, then stirring was stopped; the oil-resistant adhesive was allowed to stand at 60°C for 2 hours to defoam.

[0034] (2) Preparation of waterproof adhesive (by mass): Add 5 parts of polylactic acid to a container containing 95 parts of dichloromethane, stir at 25°C for 1.5 h, stop stirring, and let stand at 25°C for 0.5 h to defoam, and obtain waterproof adhesive.

[0035] (3) First coating: The oil-resistant coating solution from step (1) is applied to one side of the base paper using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a single-layer oil-resistant paper with an oil-resistant layer is obtained, with a coating amount of 5 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 50℃, and the drying time is 0.5 h.

[0036] (4) Second coating: The waterproof coating adhesive from step (2) is applied to the single-layer oil-proof paper from step (3) using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a biodegradable film paper is obtained with a coating amount of 10 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 25℃, and the drying time is 1 hour.

[0037] Example 3

[0038] (1) Preparation of oil-resistant adhesive (by mass): Add 1 part gellan gum and 1 part hydroxypropyl methylcellulose to a container containing 97 parts deionized water, and stir at 60°C for 2 hours to obtain the oil-resistant adhesive; add 1 part glycerin, and then continue stirring at 60°C for 1 hour, and stop stirring; let the oil-resistant adhesive stand at 60°C for 2 hours to defoam;

[0039] (2) Preparation of waterproof adhesive (by mass): Add 5 parts of polylactic acid to a container containing 95 parts of dichloromethane, stir at 25°C for 1.5 h, stop stirring, and let stand at 25°C for 0.5 h to defoam, and obtain waterproof adhesive.

[0040] (3) First coating: The oil-resistant coating solution from step (1) is applied to one side of the base paper using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a single-layer oil-resistant paper with an oil-resistant layer is obtained, with a coating amount of 5 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 50℃, and the drying time is 0.5 h.

[0041] (4) Second coating: The waterproof coating adhesive from step (2) is applied to the single-layer oil-proof paper from step (3) using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a biodegradable film paper is obtained with a coating amount of 10 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 25℃, and the drying time is 1 hour.

[0042] Example 4

[0043] (1) Preparation of oil-resistant adhesive (by mass): 1 part κ-carrageenan and 1 part hydroxypropyl methylcellulose were added to a container containing 97 parts deionized water and stirred at 60°C for 2 hours to obtain the oil-resistant adhesive; 1 part glycerin was added and stirred at 60°C for 1 hour, then stirring was stopped; the oil-resistant adhesive was allowed to stand at 60°C for 2 hours to defoam.

[0044] (2) Preparation of waterproof adhesive (by mass): Add 5 parts of polyvinyl butyral to a container containing 95 parts of anhydrous ethanol, stir at 25°C for 1.5 h, stop stirring, and let stand at 25°C for 0.5 h to defoam, and obtain waterproof adhesive.

[0045] (3) First coating: The oil-resistant coating solution from step (1) is applied to one side of the base paper using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a single-layer oil-resistant paper with an oil-resistant layer is obtained, with a coating amount of 5 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 50℃, and the drying time is 0.5 h.

[0046] (4) Second coating: The waterproof coating adhesive from step (2) is applied to the single-layer oil-proof paper from step (3) using a coating machine. After coating, it is placed in a drying oven to dry. After drying, a biodegradable film paper is obtained with a coating amount of 10 g / m². 2 The coating speed is 15 mm / s, the drying temperature is 25℃, and the drying time is 1 hour.

[0047] Example 5

[0048] Example 5 is prepared in the same way as Example 1, except that in Example 5, hydroxypropyl cellulose is replaced with sodium carboxymethyl cellulose in the oil-resistant adhesive formula.

[0049] Example 6

[0050] Example 6 is prepared in the same way as Example 1, except that the raw materials in Example 6 include, by mass, 1.2 parts of κ-carrageenan, 0.8 parts of hydroxypropyl methylcellulose, 1 part of glycerol, and 97 parts of deionized water.

[0051] Example 7

[0052] Example 7 is prepared in the same way as Example 1, except that the raw materials in Example 7 include, by mass, 0.8 parts of κ-carrageenan, 1.2 parts of hydroxypropyl methylcellulose, 1 part of glycerol, and 97 parts of deionized water.

[0053] Comparative Example 1

[0054] The difference between Comparative Example 1 and Example 1 is that the preparation of the waterproof adhesive and the second coating are omitted.

[0055] Comparative Example 2

[0056] The difference between Comparative Example 2 and Example 1 is that the preparation of the anti-oil adhesive and the first coating are missing.

[0057] Comparative Example 3

[0058] The preparation steps of Comparative Example 3 are the same as those of Example 1, except that the raw materials of Comparative Example 3 include, by mass, 1 part of hydroxypropyl methylcellulose, 1 part of glycerol, and 98 parts of deionized water.

[0059] Comparative Example 4

[0060] Comparative Example 4 was prepared in the same way as Example 1, except that the raw materials for Comparative Example 4, by mass, included: 0.2 parts κ-carrageenan, 1.8 parts hydroxypropyl methylcellulose, 1 part glycerol, and 97 parts deionized water.

[0061] Comparative Example 5

[0062] Comparative Example 5 was prepared using the same steps as Comparative Example 2, the difference being that the coating amount of the waterproof coating in Comparative Example 5 was approximately 5 g / m². 2 .

[0063] Comparative Example 6

[0064] Comparative Example 6 was prepared using the same steps as Example 1, except that the coating amount of the oil-resistant layer in Comparative Example 6 was 2 g / m². 2 .

[0065] Comparative Example 7

[0066] The preparation steps of the oil-resistant adhesive and the waterproof adhesive in Comparative Example 7 and Example 1 are the same, except that the waterproof adhesive is applied first and then the oil-resistant adhesive is applied in Comparative Example 7.

[0067] The hot water and heat-resistant oil-paper obtained from the above embodiments and comparative examples was subjected to the following performance tests:

[0068] (1) Oil resistance rating test: TAPPI T559 pm-96 standard;

[0069] (2) Waterproof performance test: TAPPI T441 om-09 standard;

[0070] (3) Mechanical performance testing: GB / T 453-2002 standard;

[0071] (4) Water resistance test: GB / T 36392-2018 standard;

[0072] (5) Oil resistance test: GB / T 36392-2018 standard, in which the test temperature for edible oil is increased to 130±5℃;

[0073] (6) Adhesion strength test: GB / T 36392-2018 standard;

[0074] The test results are shown in Table 1 below:

[0075] Table 1. Test Results of Biodegradable Fluorine-Free Hot Water and Heat-Proof Paper

[0076]

[0077]

[0078] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A biodegradable film paper, characterized by: The biodegradable film paper comprises a base paper, an oil-proof layer arranged on the base paper, and a water-proof layer arranged on the oil-proof layer, wherein The oil-proof layer is formed by coating and drying an oil-proof glue solution, the oil-proof glue solution is prepared by mixing a film-forming agent, a cellulose derivative, deionized water and glycerol in a mass ratio of 0.8-1.2: 0.8-1.2: 97: 1; the film-forming agent is gellan gum, kappa-carrageenan or iota-carrageenan, and the cellulose derivative is hydroxypropyl methyl cellulose or sodium carboxymethyl cellulose; The water-proof layer is formed by coating and drying a water-proof glue solution, the water-proof glue solution is prepared by mixing polylactic acid and dichloromethane in a mass ratio of 5-10: 90-95, or by mixing polyvinyl butyral and anhydrous ethanol in a mass ratio of 5-10: 90-95; The coating amount of the oil-proof glue solution is 3-6 g / m 2 The coating amount of the waterproof glue solution is 5-10 g / m 2 ; The preparation method comprises the following steps: (1) heating and stirring the film-forming agent, the cellulose derivative and the deionized water until they are uniformly mixed, then adding glycerol, continuing to stir until they are uniformly mixed, and then standing to remove bubbles to obtain the oil-proof glue solution; (2) mixing and stirring polylactic acid and dichloromethane, or mixing and stirring polyvinyl butyral and anhydrous ethanol, and then standing to remove bubbles to obtain the water-proof glue solution; (3) coating the oil-proof glue solution on one side of the base paper, and drying to obtain the single-layer oil-proof paper with the oil-proof layer; (4) coating the water-proof glue solution on the oil-proof layer obtained in step (3), and drying to obtain the biodegradable film paper.

2. A biodegradable film paper as claimed in claim 1, wherein: In step (1), the temperature for stirring is 60-70℃, and the temperature for standing to remove bubbles is 60-70℃.

3. The biodegradable film paper according to claim 1, wherein: In step (2), the temperature for stirring is 20-25℃, and the temperature for standing to remove bubbles is 20-25℃.

4. The biodegradable film paper of claim 1, wherein: In step (3), the coating speed is 15-20mm / s, and the drying temperature is 50-70℃.

5. The biodegradable film paper of claim 1, wherein: In step (4), the coating speed is 15-20mm / s, and the drying temperature is 20-25℃.

Images