A coating for bamboo fiber substrate combined tableware and its preparation method and application

Abstract

The present invention relates to the technical field of coatings, and in particular to a coating for bamboo fiber substrate combined tableware, a preparation method thereof and an application thereof, comprising the following raw materials in parts by weight: 30-50 parts of waterproof monomer, 10-20 parts of VAE emulsion, 1-3 parts of initiator, 1-5 parts of emulsifier, 3-7 parts of nano filler, 1-3 parts of plasticizer, 1-3 parts of curing agent, 30-60 parts of solvent and 4-8 parts of ethylene-acrylic acid copolymer. The coating of the present invention has good adhesion, peeling resistance after boiling water immersion, oil resistance and non-leakage to meet the process requirements, has good mechanical properties, is easy to process and use, has good water resistance, weather resistance, glossiness and mechanical properties after film formation, is applied to plant fiber degradable and environmentally friendly packaging lunch boxes, improves its waterproof performance, has almost no toxic side effects on the human body, is biodegradable, and completely solves the problem of plastic pollution of dining utensils.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a coating for bamboo fiber substrate combined tableware and a preparation method and application thereof. Background Art

[0002] Foam plastic fast food boxes are one of the important sources of white pollution and cause great harm to the environment. The state has ordered a complete cessation of the production and sale of foam plastic fast food boxes in 2001. In recent years, a variety of substitutes have appeared on the market, which are mainly divided into three categories: (1) plant fiber tableware; (2) starch tableware; (3) paper tableware. Since plant fiber, starch and paper tableware cannot meet the requirements of waterproof and oil-proof performance, they all need to be coated on their surfaces. In addition to the basic properties of general coatings, the coatings used for degradable fast food boxes must also meet two basic requirements: processability and hygiene. The so-called processability requires the coating to have low viscosity, high solid content, good film-forming properties, strong adhesion, anti-adhesion, high temperature baking resistance, boiling water resistance and oil resistance; the so-called hygiene requires it to be non-toxic and odorless. However, the coatings used for degradable fast food boxes in the prior art have the following disadvantages: (1) poor processability, low adhesion, easy to peel off when soaked in boiling water; (2) not oil-resistant and easy to leak; (3) toxic and contain volatile organic compounds. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a coating for bamboo fiber substrate combined tableware, which has good adhesion, peeling resistance when immersed in boiling water, oil resistance and non-leakage, thereby meeting the process requirements, and has good mechanical properties, is easy to process and use, is environmentally friendly, and has high safety in use. After film formation, it has good water resistance, weather resistance, glossiness and mechanical properties. It is applied to plant fiber degradable and environmentally friendly packaging lunch boxes to improve their waterproof performance. It has almost no toxic side effects on the human body and is biodegradable, which completely solves the problem of plastic pollution in tableware.

[0004] Another object of the present invention is to provide a method for preparing a coating for bamboo fiber substrate combined tableware, which has simple operation, convenient control, high production efficiency, low production cost, and is suitable for large-scale production.

[0005] Another object of the present invention is to provide an application method of coating for bamboo fiber substrate combined tableware, by which the coating for tableware can be evenly sprayed on the inner surface of the bamboo fiber substrate combined tableware, and a layer of tableware glue can be solidified on the surface of the tableware, which can effectively improve the oil resistance, heat resistance, and salt hydrolysis resistance of the tableware.

[0006] The objective of the present invention is achieved by the following technical scheme: A coating for bamboo fiber substrate combined tableware, comprising the following raw materials in parts by weight: 30-50 parts of waterproof monomer, 10-20 parts of VAE emulsion, 1-3 parts of initiator, 1-5 parts of emulsifier, 3-7 parts of nano filler, 1-3 parts of plasticizer, 1-3 parts of curing agent, 30-60 parts of solvent, 4-8 parts of ethylene-acrylic acid copolymer, 1-3 parts of fullerene carboxylic acid derivative and 1-3 parts of ferric hydroxide oxide; the solvent is a mixture of deionized water and glycerol in a weight ratio of 12-16:0.6-1.0.

[0007] The coating of the present invention has good adhesion, peeling resistance when immersed in boiling water, oil resistance and non-leakage, thereby meeting the process requirements, and has good mechanical properties, is easy to process and use, is environmentally friendly, and has high safety in use. It can be used to prepare food packaging materials or tableware, and has good water resistance, weather resistance, glossiness and mechanical properties after film formation. It is applied to plant fiber degradable and environmentally friendly packaging lunch boxes to improve their waterproof performance. It has almost no toxic side effects on the human body and is biodegradable, which completely solves the plastic pollution problem of tableware. Among them, the ethylene-acrylic acid copolymer used has thermoplasticity and extremely high adhesion. When MI is the same, its transparency, toughness, adhesion and environmental stress cracking resistance will increase with the increase of AA content, which can further improve the comprehensive performance of the coating; and VAE emulsion has the characteristics of plasticizing performance, good rigidity, and high initial adhesion strength, and can utilize the addition of various additives to have excellent synergistic viscosity and rapidly develop "fiber tearing adhesion", which can help increase the adhesion between the coating and tableware; the fullerene-containing complex prepared by the reaction of fullerene carboxylic acid derivatives and ferric hydroxide oxide as a degradation promoter can accelerate the degradation process of the coating film, promote the separation of paper and plastic, achieve the purpose of sufficient and rapid degradation, and have little effect on the performance of the product.

[0008] Preferably, the waterproof monomer is one or more of acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, methacrylamide, hydroxyethyl acrylate and polyacrylate.

[0009] The waterproof monomer used in the present invention has good waterproof and oil-proof properties, can improve the film-forming property and film strength of the coating, and can also enhance the adhesion of the film layer on the surface of the paper material through the interaction between the self-crosslinking group and the paper material. At the same time, it can assist in improving the coating to form a glossy and water-resistant film with strong adhesion, not easy to peel off, and good weather resistance.

[0010] Preferably, the initiator is potassium persulfate or ammonium persulfate.

[0011] Preferably, the emulsifier is one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, Tween 80, glyceryl monostearate, and fatty acid polyoxyethylene ether.

[0012] Preferably, the nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 0.8-1.2:0.3-0.7:0.4-0.8.

[0013] The nano-organic montmorillonite added in the present invention can adjust the mechanical properties of the coating film and prevent the coating film from aging prematurely. At the same time, the nano-organic montmorillonite provides a favorable environment for the growth of microorganisms, promotes the reproduction of microorganisms, and promotes the biodegradation of film paper. The introduction of nano-silicon dioxide can improve the toughening effect of the coating film and improve the cohesion.

[0014] Preferably, the plasticizer is one or more of food-grade sodium carboxymethyl cellulose, epoxidized soybean oil, tributyl citrate, and acetyl tributyl citrate.

[0015] Preferably, the curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 0.8-1.2:0.4-0.8.

[0016] The water-based amino resin used in the curing agent of the present invention has excellent water solubility and can improve the adhesion, hardness and water resistance of the paint film, while dimethylimidazole has a good curing effect and can further assist the water-based amino resin in improving the curing rate of the coating.

[0017] The invention also provides a method for preparing a coating for bamboo fiber substrate combined tableware, which is prepared by the following steps:

[0018] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight, mix evenly, heat to 65-85°C and stir at 400-800r / min for 2-6h to obtain mixture A, which is set aside.

[0019] S2. Mix the fullerene carboxylic acid derivative and ferric oxyhydroxide according to weight, stir evenly, add a plasticizer, an initiator and a curing agent, heat to 50-70° C., stir at a speed of 300-600 r / min for 40-80 min to obtain a mixture B for standby use;

[0020] S3. Add the emulsifier and mixture B to mixture A according to weight, keep the temperature at 50-70°C and stir for 30-60 minutes, then add the solvent and stir for 20-40 minutes, cool the reaction material to room temperature, and obtain tableware coating.

[0021] The present invention also provides an application method of coating for bamboo fiber substrate combined tableware. When spraying the coating, the folded combined tableware is placed in a rotating seat of a spraying device, and the coating for the tableware is sprayed on the inner surface of the tableware by using the spraying device. The spraying amount is 10-12g / ㎡. During the spraying process, the rotating seat rotates at a rate of 100-120r / min to throw out excess coating to ensure that the coating on the sprayed surface is uniform. After the spraying is completed, the tableware is taken out by a robot and placed at a temperature of 90-110°C for drying, that is, a layer of tableware coating is solidified on the surface of the tableware.

[0022] The beneficial effects of the present invention are as follows: the coating of the present invention has good adhesion, resistance to peeling when immersed in boiling water, oil resistance and non-leakage, thereby meeting the process requirements, has good mechanical properties, is easy to process and use, is environmentally friendly, and has high safety in use. It can be used to prepare food packaging materials or tableware, has good water resistance, weather resistance, glossiness and mechanical properties after film formation, and is applied to plant fiber degradable and environmentally friendly packaging lunch boxes to improve their waterproof performance. It has almost no toxic side effects on the human body and is biodegradable, thus completely solving the problem of plastic pollution in tableware.

[0023] The preparation method of the coating for bamboo fiber substrate combined tableware of the present invention is simple to operate, convenient to control, high in production efficiency, low in production cost, and suitable for large-scale production; by using the method, the coating for tableware can be well and evenly sprayed on the inner surface of the bamboo fiber substrate combined tableware, and a layer of tableware glue is solidified on the surface of the tableware, which can effectively improve the oil resistance, heat resistance, and salt hydrolysis resistance of the tableware. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0025] Example 1

[0026] A coating for bamboo fiber substrate combined tableware comprises the following raw materials in parts by weight: 30 parts of waterproof monomer, 10 parts of VAE emulsion, 1 part of initiator, 1 part of emulsifier, 3 parts of nano filler, 1 part of plasticizer, 1 part of curing agent, 30 parts of solvent, 4 parts of ethylene-acrylic acid copolymer, 1 part of fullerene carboxylic acid derivative and 1 part of ferric oxyhydroxide. The VAE emulsion adopts the VAE emulsion with product model 707 provided by Shenzhen Boshun Chemical Co., Ltd.; the ethylene-acrylic acid copolymer adopts the ethylene-acrylic acid copolymer with acrylic acid content: AA: 20%, melt index: MI: 300g / 10min, density: 0.93g / cm3 produced by Zhangjiagang Chuangli New Materials Co., Ltd.; the fullerene carboxylic acid derivative is prepared by the following method: under nitrogen protection, fullerene C60, p-carboxylbenzaldehyde and sarcosine are dispersed in toluene, and reacted at 110°C for 10 hours, the molar ratio of fullerene C60: p-carboxylbenzaldehyde: sarcosine: toluene is: 1:10:8:35, after the reaction, the obtained solid is washed with water and dried to obtain the fullerene carboxylic acid derivative.

[0027] The solvent is a mixture of deionized water and glycerol in a weight ratio of 12:0.6.

[0028] The waterproof monomer is acrylic acid, the initiator is potassium persulfate, and the emulsifier is sodium dodecylbenzene sulfonate.

[0029] The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 0.8:0.3:0.4.

[0030] The plasticizer is food grade sodium carboxymethyl cellulose.

[0031] The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 0.8:0.4; the water-based amino resin produced by Suzhou Qingtian New Materials Co., Ltd. is AA-9077 water-based amino resin, and the dimethylimidazole is provided by Shanghai Jizhi Biochemical Technology Co., Ltd. with a density of 1.0±0.1g / cm 3 , dimethylimidazole with a melting point of 85-87°C.

[0032] The coating for bamboo fiber substrate combined tableware is prepared by the following steps:

[0033] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight parts, mix evenly, heat to 65°C and stir at 400r / min for 2h to obtain mixture A, which is set aside.

[0034] S2. According to weight parts, the fullerene carboxylic acid derivative and iron oxyhydroxide are mixed and stirred, and then a plasticizer, an initiator and a curing agent are added, and the mixture is heated to 50° C. and stirred at a speed of 300 r / min for 40 min to obtain a mixture B for standby use;

[0035] S3. Add the emulsifier and mixture B to mixture A according to weight parts, keep the temperature at 50° C. and stir for 30 minutes, then add the solvent and stir for 20 minutes, cool the reaction material to room temperature, and obtain tableware coating.

[0036] A method for applying coating for combined tableware with a bamboo fiber substrate comprises the following steps: placing the folded combined tableware in a rotating seat of a spraying device, spraying the coating for the tableware on the inner surface of the tableware by using the spraying device, and spraying the coating on the inner surface of the tableware in an amount of 10 g / m2. During the spraying process, the rotating seat rotates at a rate of 100 r / min to throw out excess coating. After the spraying is completed, the tableware is taken out by a robot and dried at a temperature of 90°C, so that a layer of tableware coating is solidified on the surface of the tableware.

[0037] Example 2

[0038] A coating for bamboo fiber substrate combined tableware comprises the following raw materials in parts by weight: 35 parts of waterproof monomer, 13 parts of VAE emulsion, 1.5 parts of initiator, 2 parts of emulsifier, 4 parts of nano filler, 1.5 parts of plasticizer, 1.5 parts of curing agent, 38 parts of solvent, 5 parts of ethylene-acrylic acid copolymer, 1.5 parts of fullerene carboxylic acid derivative and 1.5 parts of ferric oxyhydroxide. The VAE emulsion adopts the VAE emulsion with product model 707 provided by Shenzhen Boshun Chemical Co., Ltd.; the ethylene-acrylic acid copolymer adopts the ethylene-acrylic acid copolymer with acrylic acid content: AA: 20%, melt index: MI: 300g / 10min, density: 0.93g / cm3 produced by Zhangjiagang Chuangli New Materials Co., Ltd.; the fullerene carboxylic acid derivative is prepared by the following method: under nitrogen protection, fullerene C60, p-carboxylbenzaldehyde and sarcosine are dispersed in toluene, and reacted at 110°C for 10 hours, the molar ratio of fullerene C60: p-carboxylbenzaldehyde: sarcosine: toluene is: 1:10:8:35, after the reaction, the obtained solid is washed with water and dried to obtain the fullerene carboxylic acid derivative.

[0039] The solvent is a mixture of deionized water and glycerol in a weight ratio of 13:0.7.

[0040] The waterproof monomer is butyl acrylate, the initiator is ammonium persulfate, and the emulsifier is sodium dodecyl sulfate.

[0041] The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 0.9:0.4:0.5.

[0042] The plasticizer is tributyl citrate.

[0043] The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 0.9:0.5; the water-based amino resin produced by Suzhou Qingtian New Materials Co., Ltd. is AA-9077 water-based amino resin, and the dimethylimidazole is provided by Shanghai Jizhi Biochemical Technology Co., Ltd. with a density of 1.0±0.1g / cm 3 , dimethylimidazole with a melting point of 85-87°C.

[0044] The coating for bamboo fiber substrate combined tableware is prepared by the following steps:

[0045] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight parts, mix evenly, heat to 70°C and stir at 500r / min for 3h to obtain mixture A, which is set aside.

[0046] S2. According to weight parts, the fullerene carboxylic acid derivative and iron oxyhydroxide are mixed and stirred, and then a plasticizer, an initiator and a curing agent are added, heated to 55° C., and stirred at a speed of 380 r / min for 50 min to obtain a mixture B for standby use;

[0047] S3. According to weight parts, emulsifier and mixture B are added to mixture A, and the temperature is maintained at 55° C. and stirred for 38 minutes. Then, the solvent is added and stirred for 25 minutes. The reaction material is cooled to room temperature to obtain tableware coating.

[0048] A method for applying coating for combined tableware with a bamboo fiber substrate comprises the following steps: placing the folded combined tableware in a rotating seat of a spraying device during spraying; spraying the tableware coating on the inner surface of the tableware by using the spraying device; and spraying the coating in an amount of 10.5 g / m2. During the spraying process, the rotating seat rotates at a rate of 105 r / min to throw out excess coating. After spraying is completed, the tableware is taken out by a robot and dried at a temperature of 95°C, so that a layer of tableware coating is solidified on the surface of the tableware.

[0049] Example 3

[0050] A coating for bamboo fiber substrate combined tableware comprises the following raw materials in parts by weight: 40 parts of waterproof monomer, 15 parts of VAE emulsion, 2 parts of initiator, 3 parts of emulsifier, 5 parts of nano filler, 2 parts of plasticizer, 2 parts of curing agent, 45 parts of solvent, 6 parts of ethylene-acrylic acid copolymer, 2 parts of fullerene carboxylic acid derivative and 2 parts of ferric oxyhydroxide. The VAE emulsion adopts the VAE emulsion with product model 707 provided by Shenzhen Boshun Chemical Co., Ltd.; the ethylene-acrylic acid copolymer adopts the ethylene-acrylic acid copolymer with acrylic acid content: AA: 20%, melt index: MI: 300g / 10min, density: 0.93g / cm3 produced by Zhangjiagang Chuangli New Materials Co., Ltd.; the fullerene carboxylic acid derivative is prepared by the following method: under nitrogen protection, fullerene C60, p-carboxylbenzaldehyde and sarcosine are dispersed in toluene, and reacted at 110°C for 10 hours, the molar ratio of fullerene C60: p-carboxylbenzaldehyde: sarcosine: toluene is: 1:10:8:35, after the reaction, the obtained solid is washed with water and dried to obtain the fullerene carboxylic acid derivative.

[0051] The solvent is a mixture of deionized water and glycerol in a weight ratio of 14:0.8.

[0052] The waterproof monomer is a mixture of acrylic acid, ethyl acrylate, hydroxyethyl acrylate and polyacrylate in a weight ratio of 0.4:0.8:0.7:1.0.

[0053] The initiator is potassium persulfate.

[0054] The emulsifier is a mixture of sodium dodecylbenzene sulfonate, glyceryl monostearate and fatty acid polyoxyethylene ether in a weight ratio of 0.8:0.7:1.0.

[0055] The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 1.0:0.5:0.6.

[0056] The plasticizer is a mixture of food-grade sodium carboxymethyl cellulose, epoxy soybean oil and acetyl tributyl citrate in a weight ratio of 0.5:0.8:0.7.

[0057] The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 1.0:0.6; the water-based amino resin produced by Suzhou Qingtian New Materials Co., Ltd. is AA-9077 water-based amino resin, and the dimethylimidazole is provided by Shanghai Jizhi Biochemical Technology Co., Ltd. with a density of 1.0±0.1g / cm 3 , dimethylimidazole with a melting point of 85-87°C.

[0058] The coating for bamboo fiber substrate combined tableware is prepared by the following steps:

[0059] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight parts, mix evenly, heat to 75°C and stir at 600r / min for 4h to obtain mixture A, which is set aside.

[0060] S2. According to weight parts, the fullerene carboxylic acid derivative and iron oxyhydroxide are mixed and stirred, and then a plasticizer, an initiator and a curing agent are added, heated to 60° C., and stirred at a speed of 480 r / min for 60 min to obtain a mixture B for standby use;

[0061] S3. According to weight parts, emulsifier and mixture B are added to mixture A, and the temperature is maintained at 60° C. and stirred for 45 minutes. Then, the solvent is added and stirred for 30 minutes. The reaction material is cooled to room temperature to obtain tableware coating.

[0062] A method for applying coating for composite tableware with a bamboo fiber substrate comprises the following steps: placing the folded composite tableware in a rotating seat of a spraying device during spraying; spraying the coating on the inner surface of the tableware by using the spraying device; and spraying the coating on the inner surface of the tableware in an amount of 11 g / m2. During the spraying process, the rotating seat rotates at a rate of 110 r / min to throw out excess coating. After the spraying is completed, the tableware is taken out by a robot and dried at a temperature of 100°C, so that a layer of tableware coating is solidified on the surface of the tableware.

[0063] Example 4

[0064] A coating for bamboo fiber substrate combined tableware comprises the following raw materials in parts by weight: 45 parts of waterproof monomer, 18 parts of VAE emulsion, 2.5 parts of initiator, 4 parts of emulsifier, 6 parts of nano filler, 2.5 parts of plasticizer, 2.5 parts of curing agent, 52 parts of solvent, 7 parts of ethylene-acrylic acid copolymer, 2.5 parts of fullerene carboxylic acid derivative and 2.5 parts of ferric oxyhydroxide. The VAE emulsion adopts the VAE emulsion with product model 707 provided by Shenzhen Boshun Chemical Co., Ltd.; the ethylene-acrylic acid copolymer adopts the ethylene-acrylic acid copolymer with acrylic acid content: AA: 20%, melt index: MI: 300g / 10min, density: 0.93g / cm3 produced by Zhangjiagang Chuangli New Materials Co., Ltd.; the fullerene carboxylic acid derivative is prepared by the following method: under nitrogen protection, fullerene C60, p-carboxylbenzaldehyde and sarcosine are dispersed in toluene, and reacted at 110°C for 10 hours, the molar ratio of fullerene C60: p-carboxylbenzaldehyde: sarcosine: toluene is: 1:10:8:35, after the reaction, the obtained solid is washed with water and dried to obtain the fullerene carboxylic acid derivative.

[0065] The solvent is a mixture of deionized water and glycerol in a weight ratio of 15:0.9.

[0066] The waterproof monomer is polyacrylate, the initiator is potassium persulfate, and the emulsifier is sodium dodecyl sulfate.

[0067] The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 1.1:0.6:0.7.

[0068] The plasticizer is tributyl citrate.

[0069] The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 1.12:0.7; the water-based amino resin produced by Suzhou Qingtian New Materials Co., Ltd. is AA-9077 water-based amino resin, and the dimethylimidazole is provided by Shanghai Jizhi Biochemical Technology Co., Ltd. with a density of 1.0±0.1g / cm 3 , dimethylimidazole with a melting point of 85-87°C.

[0070] The coating for bamboo fiber substrate combined tableware is prepared by the following steps:

[0071] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight parts, mix evenly, heat to 80°C and stir at 700r / min for 5h to obtain mixture A, which is set aside.

[0072] S2. According to weight parts, the fullerene carboxylic acid derivative and iron oxyhydroxide are mixed and stirred, and then a plasticizer, an initiator and a curing agent are added, heated to 65° C., and stirred at a speed of 520 r / min for 70 min to obtain a mixture B for standby use;

[0073] S3. According to weight parts, emulsifier and mixture B are added to mixture A, and the temperature is maintained at 65° C. and stirred for 52 minutes. Then, the solvent is added and stirred for 35 minutes. The reaction material is cooled to room temperature to obtain tableware coating.

[0074] A method for applying coating for combined tableware with a bamboo fiber substrate comprises the following steps: placing the folded combined tableware in a rotating seat of a spraying device, spraying the coating for the tableware on the inner surface of the tableware by using the spraying device, and spraying the coating on the inner surface of the tableware in an amount of 11.5 g / m2. During the spraying process, the rotating seat rotates at a rate of 115 r / min to throw out excess coating. After the spraying is completed, the tableware is taken out by a robot and dried at a temperature of 105°C, so that a layer of tableware coating is solidified on the surface of the tableware.

[0075] Example 5

[0076] A coating for bamboo fiber substrate combined tableware comprises the following raw materials in parts by weight: 50 parts of waterproof monomer, 20 parts of VAE emulsion, 3 parts of initiator, 5 parts of emulsifier, 7 parts of nano filler, 3 parts of plasticizer, 3 parts of curing agent, 60 parts of solvent, 8 parts of ethylene-acrylic acid copolymer, 3 parts of fullerene carboxylic acid derivative and 3 parts of ferric oxyhydroxide. The VAE emulsion adopts the VAE emulsion with product model 707 provided by Shenzhen Boshun Chemical Co., Ltd.; the ethylene-acrylic acid copolymer adopts the ethylene-acrylic acid copolymer with acrylic acid content: AA: 20%, melt index: MI: 300g / 10min, density: 0.93g / cm3 produced by Zhangjiagang Chuangli New Materials Co., Ltd.; the fullerene carboxylic acid derivative is prepared by the following method: under nitrogen protection, fullerene C60, p-carboxylbenzaldehyde and sarcosine are dispersed in toluene, and reacted at 110°C for 10 hours, the molar ratio of fullerene C60: p-carboxylbenzaldehyde: sarcosine: toluene is: 1:10:8:35, after the reaction, the obtained solid is washed with water and dried to obtain the fullerene carboxylic acid derivative.

[0077] The solvent is a mixture of deionized water and glycerol in a weight ratio of 16:1.0.

[0078] The waterproof monomer is acrylic acid, the initiator is potassium persulfate, and the emulsifier is glyceryl monostearate.

[0079] The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 1.2:0.7:0.8.

[0080] The plasticizer is food grade sodium carboxymethyl cellulose.

[0081] The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 1.2:0.8; the water-based amino resin produced by Suzhou Qingtian New Materials Co., Ltd. is AA-9077 water-based amino resin, and the dimethylimidazole is provided by Shanghai Jizhi Biochemical Technology Co., Ltd. with a density of 1.0±0.1g / cm 3 , dimethylimidazole with a melting point of 85-87°C.

[0082] The coating for bamboo fiber substrate combined tableware is prepared by the following steps:

[0083] S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight parts, mix evenly, heat to 85°C and stir at 800r / min for 6h to obtain mixture A, which is set aside.

[0084] S2. According to weight parts, the fullerene carboxylic acid derivative and iron oxyhydroxide are mixed and stirred, and then a plasticizer, an initiator and a curing agent are added, and the mixture is heated to 70° C. and stirred at a speed of 600 r / min for 80 min to obtain a mixture B for standby use;

[0085] S3. According to weight parts, the emulsifier and mixture B are added to mixture A, and the temperature is maintained at 70° C. and stirred for 60 minutes. Then the solvent is added and stirred for 40 minutes. The reaction material is cooled to room temperature to obtain a coating for tableware.

[0086] A method for applying coating for combined tableware with a bamboo fiber substrate comprises the following steps: placing the folded combined tableware in a rotating seat of a spraying device, spraying the coating for the tableware on the inner surface of the tableware by using the spraying device, and spraying the coating on the inner surface of the tableware in an amount of 12 g / m2. During the spraying process, the rotating seat rotates at a rate of 120 r / min to throw out excess coating. After the spraying is completed, the tableware is taken out by a robot and dried at a temperature of 110°C, so that a layer of tableware coating is solidified on the surface of the tableware.

[0087] Comparative Example 1

[0088] The difference between this comparative example and the above-mentioned Example 3 is that no waterproof monomer is added to the raw materials of the coating for bamboo fiber substrate combined tableware in this comparative example. The rest of the contents of this comparative example are the same as those of Example 3, and will not be repeated here.

[0089] The coating for bamboo fiber substrate combined tableware prepared in Example 3 and Comparative Example 1, and the NY-2601 water-based coating provided by Shenzhen Nengyu Ecological Chemical Technology Co., Ltd. were tested, and the results are shown in Table 1 below:

[0090] Oil resistance performance evaluation method: Tested according to standard GB / T 5406-2002;

[0091] Water resistance evaluation method: fold the coated paper into a 10*10*5cm paper container, add 50g of water into the paper container, leave it for 24 hours and observe whether it leaks;

[0092] Adhesion: Use 3M 810 tape to stick to the varnish coating surface, press the tape with your thumb to expel the bubbles below, make the tape and varnish completely fit, leave it for 1 minute, pull the tape away quickly and forcefully to see if the varnish falls off. The evaluation results are divided into 1-5 levels, 1 is the best, no fall off, 5 is the worst, completely fall off;

[0093] High temperature holding force: A temperature-type adhesive tape holding force tester (MIDEL KJ-6012, Dongguan Kejian Testing Instrument Co., Ltd.) was used to conduct a holding force test at 100°C to evaluate the high temperature resistance of the tape.

[0094] Boiling water resistance test: The determination method refers to GB18006.1-1999 "General Technical Requirements for Disposable Degradable Tableware".

[0095] Table 1

[0096] project Example 1 Comparative Example 1 Commercially available products Oil resistance(g) 0.00 0.56 1.21 Water resistance No water leakage There is a water leak No water leakage Adhesion 1 2 2 High temperature adhesion 4 hours 45 minutes 2 hours 45 minutes 2 hours 12 minutes Boiling water resistance test ≥3hr ≥1hr ≥1hr

[0097] It can be seen from the data in the table that the coating for combined tableware with bamboo fiber substrate prepared in Example 3 of the present invention has excellent adhesion, water and oil resistance, and high-temperature adhesion; wherein, the addition of waterproof monomer effectively improves the comprehensive performance of the coating for combined tableware with bamboo fiber substrate, which is beneficial to improving the comprehensive performance of the tableware after the coating for combined tableware with bamboo fiber substrate is coated with a membrane.

[0098] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A coating for bamboo fiber substrate combined tableware, characterized in that: The invention comprises the following raw materials in parts by weight: 30-50 parts of waterproof monomer, 10-20 parts of VAE emulsion, 1-3 parts of initiator, 1-5 parts of emulsifier, 3-7 parts of nano filler, 1-3 parts of plasticizer, 1-3 parts of curing agent, 30-60 parts of solvent, 4-8 parts of ethylene-acrylic acid copolymer, 1-3 parts of fullerene carboxylic acid derivative and 1-3 parts of iron oxyhydroxide; The waterproof monomer is one or more of acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, methacrylamide, hydroxyethyl acrylate and polyacrylate; The nano filler is a mixture of nano organic montmorillonite, nano silicon dioxide and nano calcium carbonate in a weight ratio of 0.8-1.2:0.3-0.7:0.4-0.8; The curing agent is a mixture of water-based amino resin and dimethylimidazole in a weight ratio of 0.8-1.2:0.4-0.

8.

2. The coating for bamboo fiber substrate combined tableware according to claim 1, characterized in that: The initiator is potassium persulfate or ammonium persulfate.

3. The coating for bamboo fiber substrate combined tableware according to claim 1, characterized in that: The emulsifier is one or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, Tween 80, glyceryl monostearate, and fatty acid polyoxyethylene ether.

4. The coating for bamboo fiber substrate combined tableware according to claim 1, characterized in that: The plasticizer is one or more of food-grade sodium carboxymethyl cellulose, epoxidized soybean oil, tributyl citrate, and acetyl tributyl citrate.

5. A method for preparing a coating for bamboo fiber substrate combined tableware according to any one of claims 1 to 4, characterized in that: Prepared by the following steps: S1. Add waterproof monomer, VAE emulsion, ethylene-acrylic acid copolymer and nanofiller into a reaction kettle according to weight, mix evenly, heat to 65-85°C and stir at 400-800r / min for 2-6h to obtain mixture A, which is set aside. S2. Mix the fullerene carboxylic acid derivative and ferric oxyhydroxide according to weight, stir evenly, add a plasticizer, an initiator and a curing agent, heat to 50-70° C., stir at a speed of 300-600 r / min for 40-80 min to obtain a mixture B for standby use; S3. Add the emulsifier and mixture B to mixture A according to weight, keep the temperature at 50-70°C and stir for 30-60 minutes, then add the solvent and stir for 20-40 minutes, cool the reaction material to room temperature, and obtain tableware coating.

6. A method for applying the coating for bamboo fiber substrate combined tableware according to any one of claims 1 to 4, characterized in that: When spraying the paint, put the folded combined tableware into the rotating seat of the spraying equipment, and use the spraying equipment to spray the tableware paint on the inner surface of the tableware. The spraying amount is 10-12g / ㎡. During the spraying process, the rotating seat rotates at a rate of 100-120r / min to throw out the excess paint. After the spraying is completed, the tableware is taken out by a robot and placed at a temperature of 90-110℃ for drying, that is, a layer of tableware paint is solidified on the surface of the tableware.