A fold-resistant high-transparency environment-friendly water-based transfer film and a preparation method thereof

Abstract

This invention relates to the field of transfer film technology, specifically to a fold-resistant, high-permeability, environmentally friendly waterborne transfer film and its preparation method. The method includes the following steps: Step 1: Adding polyether-type waterborne polyurethane, polyester-type waterborne polyurethane, waterborne polyacrylate, leveling agent, film-forming aid, defoamer, and water to a container and mixing them evenly to obtain a waterborne coating; Step 2: Performing corona treatment on one side of the substrate layer, and then coating this side with the waterborne coating, controlling the coating wet weight at 4-8 g / m². 2 Step 3: Drying to obtain a water-based coating layer; Step 4: Aluminizing the water-based coating layer to obtain an aluminum-plated layer, then molding and printing the aluminum-plated layer and alkali washing; Step 5: Applying a water-based adhesive to the aluminum-plated layer with a wet weight of 3-6 g / m². 2 A protective film is then applied to obtain a fold-resistant, highly transparent, and environmentally friendly water-based transfer film. The water-based transfer film prepared by this invention has excellent fold resistance and high transparency, is environmentally friendly, and is more suitable for current market demands.

Description

Technical Field

[0001] This invention relates to the field of transfer membrane technology, specifically to a fold-resistant, high-permeability, environmentally friendly water-based transfer membrane and its preparation method. Background Technology

[0002] Laser transfer film boasts both an attractive appearance and excellent anti-counterfeiting features, and its low production cost makes it widely used in various industries such as decoration, packaging, and printing. Traditional laser transfer films mainly use organic solvents (such as methyl ethyl ketone, ethyl acetate, and butyl acetate) to laminate the film with the substrate. However, these organic solvents produce strong, toxic, and irritating odors during both production and coating processes, posing potential health threats to human health.

[0003] On the other hand, with the improvement of people's living standards in recent years, these non-environmentally friendly transfer films are being gradually abandoned by consumers, and more and more manufacturers are beginning to develop environmentally friendly water-based transfer films. However, the existing water-based transfer films on the market have certain defects in product performance and quality, such as being not resistant to folding and exhibiting aluminum shedding after only 7 to 10 folds.

[0004] Based on this, the present invention provides a method for preparing a fold-resistant, high-transparency, environmentally friendly water-based transfer membrane, which can better meet the needs of consumers and has practical application significance. Summary of the Invention

[0005] The purpose of this invention is to provide a fold-resistant, high-permeability, environmentally friendly waterborne transfer membrane and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A fold-resistant, high-transparency, environmentally friendly water-based transfer membrane, comprising, from bottom to top, a base layer, a water-based coating layer, an aluminum-coated layer, an adhesive layer, and a protective layer.

[0008] Furthermore, the substrate layer includes, but is not limited to, any one of PET film, PVC film, PETG film, and BOPP film.

[0009] Furthermore, the water-based coating layer is obtained by applying and drying water-based coating;

[0010] The water-based coating comprises the following components by weight: 10-25 parts of polyether-type water-based polyurethane, 10-25 parts of polyester-type water-based polyurethane, 5-15 parts of water-based polyacrylate, 0.1-0.5 parts of leveling agent, 0.15-0.3 parts of defoamer, 1.5-3.5 parts of film-forming aid, and 40-80 parts of water.

[0011] Furthermore, the aluminum plating process of the aluminum plating layer is as follows: under high vacuum conditions of 0.01 to 0.05 Pa, the aluminum wire is heated to 1400°C and vaporized in a vacuum aluminum plating machine, and then it is attached to the water-based coating layer to form an aluminum plating layer with a thickness of 20 to 50 nm.

[0012] Furthermore, the adhesive layer is obtained by coating and drying with a water-based adhesive.

[0013] Furthermore, the protective layer is a CPP film.

[0014] Furthermore, the preparation method of the fold-resistant, high-transparency, environmentally friendly aqueous transfer membrane includes the following steps:

[0015] Step 1: Add polyether-based waterborne polyurethane, polyester-based waterborne polyurethane, waterborne polyacrylate, leveling agent, film-forming aid, defoamer, and water into a container and mix well to obtain a waterborne coating.

[0016] Step 2: Perform corona treatment on one side of the substrate, and then apply a water-based coating to that side, controlling the wet weight at 4-8 g / m². 2 Drying yields a water-based coating layer;

[0017] Step 3: Aluminum plating is performed on the water-based coating layer to obtain an aluminum plating layer, and then the aluminum plating layer is subjected to molding printing and alkaline washing;

[0018] Step 4: Apply a water-based adhesive to the aluminum plating layer, with a wet coating weight of 3-6 g / m². 2 A protective film is then applied to obtain a fold-resistant, highly transparent, environmentally friendly water-based transfer membrane.

[0019] Furthermore, the preparation method of the polyether-type waterborne polyurethane is as follows: (1) Under the protection of an inert gas, polyether diol is added to a reaction vessel, stirred and heated to 60-80°C, then diisocyanate and catalyst are added, mixed evenly, and the prepolymerization reaction is carried out for 2-4 hours. The reaction is then stopped to obtain prepolymer I; (2) hydrophilic chain extender I and organic solvent are added to prepolymer I, stirred and heated to 60-80°C, and the chain extension reaction is carried out for 1-3 hours. The reaction is then stopped, and the polyether-type waterborne polyurethane is obtained after separation and purification.

[0020] Furthermore, the mass ratio of the polyether diol, diisocyanate, catalyst, and hydrophilic chain extender I is 10:20:0.1:(5-10).

[0021] Furthermore, the polyether diol includes, but is not limited to, any one of polytetrahydrofuran ether diol, polypropylene glycol, and polyoxypropylene glycol, with a molecular weight of 600 to 2000.

[0022] Furthermore, the diisocyanate includes, but is not limited to, at least one of isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4-toluene diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0023] Furthermore, the catalyst is dibutyltin dilaurate or stannous octoate.

[0024] Furthermore, the preparation method of the hydrophilic chain extender I is as follows: (1) DL-cysteine ​​and photoinitiator are added to a reaction vessel containing unsaturated diol, and after stirring and dispersing for 5 to 15 min, the reaction is irradiated with 365 nm ultraviolet light for 15 to 60 min, and the reaction is ended to obtain product I; (2) Sodium p-aminobenzenesulfonate, condensing agent and 4-dimethylaminopyridine are added to product I, and the reaction is stirred at 0 to 40 °C for 12 to 48 h, and the reaction is ended. After separation and purification, hydrophilic chain extender I is obtained.

[0025] Furthermore, the mass ratio of the unsaturated diol and DL-cysteine ​​is 3:4.

[0026] Furthermore, the amount of photoinitiator added is 2-5% of the mass of the unsaturated diol.

[0027] Furthermore, the unsaturated diol includes, but is not limited to, any one of butenyl glycol and 1,4-dihydroxy-2-butene.

[0028] Furthermore, the mass ratio of product I, sodium p-aminobenzenesulfonate, condensing agent, and 4-dimethylaminopyridine is 1:(1-2):1:1.

[0029] Furthermore, the condensing agent includes, but is not limited to, any one of N,N'-dicyclohexylcarbodiimide, N,N-diisopropylcarbodiimide, 1,3-di(2,2-dimethyl-1,3-dioxolane-4-ylmethyl)carbodiimide, and 1-hydroxybenzotriazole.

[0030] Furthermore, the preparation method of the polyester-type waterborne polyurethane is as follows: (1) Under the protection of an inert gas, polyester diol is added to a reaction vessel, stirred and heated to 60-80°C, then diisocyanate and catalyst are added, mixed evenly, and the prepolymerization reaction is carried out for 2-4 hours. The reaction is then stopped to obtain prepolymer II; (2) hydrophilic chain extender II and organic solvent are added to prepolymer II, stirred and heated to 60-80°C, and the chain extension reaction is carried out for 1-3 hours. The reaction is then stopped, and the polyester-type waterborne polyurethane is obtained after separation and purification.

[0031] Furthermore, the mass ratio of the polyester diol, diisocyanate, catalyst, and hydrophilic chain extender II is 10:20:0.1:(5-10).

[0032] Furthermore, the polyester diol includes, but is not limited to, at least one of polyethylene adipate, diethylene glycol oxophosphate, and neopentyl glycol oxophosphate, with a molecular weight of 1000 to 2000.

[0033] Further, the preparation method of the hydrophilic chain extender II is as follows: (1) Sodium p-aminobenzenesulfonate and diisocyanate are added to the reaction vessel, and under the protection of inert gas, the temperature is raised to 90-100℃ and stirred for 12-24h. After the reaction is stopped, after the temperature is restored to room temperature, excess n-pentane is added, the precipitate is collected, and washed several times with n-pentane. The product II is obtained by vacuum drying at 50℃. (2) Product II and 2-amino-2-methyl-1,3-propanediol are added to the reaction vessel containing chloroform. Under the protection of inert gas, the temperature is raised to 50-70℃ and refluxed for 6-24h. After the reaction is stopped, the hydrophilic chain extender II is obtained by separation and purification.

[0034] Furthermore, the mass ratio of sodium p-aminobenzenesulfonate to diisocyanate is 1:(5-10).

[0035] Furthermore, the mass ratio of product II to 2-amino-2-methyl-1,3-propanediol is 2:1.

[0036] Furthermore, the leveling agent is a water-based leveling agent.

[0037] Furthermore, the defoamer is an aqueous defoamer.

[0038] Furthermore, the film-forming aid is one or more of the following: alcohol ester film-forming aids, alcohol ether film-forming aids, and alcohol ether ester film-forming aids.

[0039] In this invention, an unsaturated diol and DL-cysteine ​​undergo a click reaction, followed by an amidation reaction with sodium p-aminobenzenesulfonate to prepare hydrophilic chain extender I. This hydrophilic chain extender I is then used to prepare a polyether-type waterborne polyurethane (polyether-type waterborne polyurethane exhibits weaker interaction forces, lower crystallinity, and higher transparency). This hydrophilic chain extender I is a sulfonic acid-type chain extender, which enhances the hydrophilicity of the polyurethane. Furthermore, it can form weak hydrogen bonds with the polyether diol, thereby imparting a certain degree of toughness to the material and improving the folding resistance of the waterborne transfer film. Moreover, considering that polyether-type waterborne polyurethane is prone to hardening and embrittlement (poor folding resistance), the inventors further prepared a polyester-type waterborne polyurethane (polyester-type waterborne polyurethane has high ester group polarity, is prone to crystallization, and has low transparency). The two are then combined to obtain a waterborne transfer film with even better toughness. This polyester-based waterborne polyurethane incorporates hydrophilic chain extender II, which also possesses the ability to form weak hydrogen bonds with polyester polyols, thereby imparting a certain degree of toughness to the material and improving the folding resistance of the waterborne transfer film. Furthermore, the blending of two waterborne polyurethanes yields a waterborne transfer film with excellent overall performance. The addition of waterborne polyacrylate and the blending of multiple resins further reduce crystallinity, enhancing transparency and also contributing to improved toughness of the waterborne transfer film.

[0040] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0041] (1) The present invention prepared two different waterborne polyurethanes (polyether type and polyester type), and the two were compounded to obtain a waterborne coating with excellent hydrophilicity. The waterborne coating layer obtained by the waterborne coating has excellent toughness.

[0042] (2) The aqueous transfer membrane prepared by the present invention has excellent folding resistance and transparency. It does not contain volatile solvents that may harm human health during use and production, and it does not pollute the environment. It is more suitable for today's market demand. Detailed Implementation

[0043] The following are preferred embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. For those skilled in the art, all other embodiments obtained by those skilled in the art without creative effort without departing from the principles of the embodiments of the present invention are within the scope of protection of the present invention.

[0044] Example 1: A method for preparing a fold-resistant, high-transparency, environmentally friendly waterborne transfer membrane:

[0045] Step 1: 1. Preparation of hydrophilic chain extender I: (1) Add 8 parts of DL-cysteine ​​and 0.18 parts of photoinitiator to a reaction vessel containing 6 parts of butenyl glycol. After stirring and dispersing for 10 min, irradiate with 365 nm ultraviolet light for 30 min to obtain product I; (2) Add 12 parts of sodium p-aminobenzenesulfonate, 10 parts of N,N'-dicyclohexylcarboimide and 10 parts of 4-dimethylaminopyridine to 10 parts of product I. Stir and react at 20 °C for 24 h. After the reaction is completed, the hydrophilic chain extender I is obtained by separation and purification.

[0046] 2. Preparation of polyether-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polytetrahydrofuran ether diol were added to the reaction vessel, stirred and heated to 75°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and the prepolymerization reaction was carried out at the temperature for 3 hours. The reaction was then stopped to obtain prepolymer I; (2) 8 parts of hydrophilic chain extender I and 40 parts of acetone were added to prepolymer I, stirred and heated to 70°C, and the chain extension reaction was carried out at the temperature for 2 hours. The reaction was then stopped, and the polyether-type waterborne polyurethane was obtained after separation and purification.

[0047] 3. Preparation of hydrophilic chain extender II: (1) Add 1 part of sodium p-aminobenzenesulfonate and 8 parts of 2,4-toluene diisocyanate to a reaction vessel. Under nitrogen protection, heat to 100°C and stir for 18 h. After the reaction is stopped, after the temperature is restored to room temperature, add excess n-pentane, collect the precipitate, wash it 3 times with n-pentane, and dry it under vacuum at 50°C to obtain product II; (2) Add 6 parts of product II and 3 parts of 2-amino-2-methyl-1,3-propanediol to a reaction vessel containing 10 parts of chloroform. Under nitrogen protection, heat to 60°C and reflux for 18 h. After the reaction is stopped, the hydrophilic chain extender II is obtained by separation and purification.

[0048] 4. Preparation of polyester-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polyethylene adipate were added to the reaction vessel, stirred and heated to 70°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and the prepolymerization reaction was carried out at the temperature for 3 hours. The reaction was then stopped to obtain prepolymer II; (2) 8 parts of hydrophilic chain extender II and 40 parts of acetone were added to prepolymer II, stirred and heated to 70°C, and the chain extension reaction was carried out at the temperature for 2 hours. The reaction was then stopped, and the polyester-type waterborne polyurethane was obtained after separation and purification.

[0049] 5. Add polyether-type waterborne polyurethane, polyester-type waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 22 parts of polyether-type waterborne polyurethane, 15 parts of polyester-type waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water;

[0050] Step 2: Corona treatment is applied to one side of the PET film, and then it is placed on a coating machine and coated at a speed of 300 mm / min, with the coating wet weight controlled at 6 ± 0.2 g / m. 2 Finally, it is dried to obtain a water-based coating layer;

[0051] Step 3: The film obtained in Step 2 is aluminum-coated using a vacuum aluminum plating machine. Under a high vacuum of 0.01 Pa, the aluminum wire is heated to 1400℃ and vaporized. Then, an aluminum plating layer with a thickness of 40 nm is deposited on the water-based coating layer. The aluminum plating layer is then subjected to molding printing and alkaline washing treatment.

[0052] Step 4: Place the film obtained in Step 3 on a coating machine and coat it on the aluminum-coated side at a speed of 300 mm / min, controlling the coating wet weight at 5 ± 0.2 g / m. 2 Finally, a CPP film is applied to obtain a fold-resistant, high-transparency, environmentally friendly water-based transfer membrane.

[0053] Example 2: A method for preparing a fold-resistant, high-transparency, environmentally friendly waterborne transfer membrane:

[0054] Step 1: 1. Preparation of hydrophilic chain extender I: (1) Add 8 parts of DL-cysteine ​​and 0.18 parts of photoinitiator to a reaction vessel containing 6 parts of butenyl glycol. After stirring and dispersing for 10 min, irradiate with 365 nm ultraviolet light for 30 min to obtain product I; (2) Add 10 parts of sodium p-aminobenzenesulfonate, 10 parts of N,N'-dicyclohexylcarboimide and 10 parts of 4-dimethylaminopyridine to 10 parts of product I. Stir and react at 20 °C for 24 h. After the reaction is completed, the hydrophilic chain extender I is obtained by separation and purification.

[0055] 2. Preparation of polyether-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polytetrahydrofuran ether diol were added to the reaction vessel, stirred and heated to 75°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and the prepolymerization reaction was carried out at the temperature for 3 hours. The reaction was then stopped to obtain prepolymer I; (2) 5 parts of hydrophilic chain extender I and 40 parts of acetone were added to prepolymer I, stirred and heated to 70°C, and the chain extension reaction was carried out at the temperature for 2 hours. The reaction was then stopped, and the polyether-type waterborne polyurethane was obtained after separation and purification.

[0056] 3. Preparation of hydrophilic chain extender II: (1) Add 1 part of sodium p-aminobenzenesulfonate and 5 parts of 2,4-toluene diisocyanate to a reaction vessel. Under nitrogen protection, heat to 100°C and stir for 18 h. After the reaction is stopped, after the temperature returns to room temperature, add excess n-pentane, collect the precipitate, wash it 3 times with n-pentane, and dry it under vacuum at 50°C to obtain product II; (2) Add 6 parts of product II and 3 parts of 2-amino-2-methyl-1,3-propanediol to a reaction vessel containing 10 parts of chloroform. Under nitrogen protection, heat to 60°C and reflux for 18 h. After the reaction is stopped, the hydrophilic chain extender II is obtained by separation and purification.

[0057] 4. Preparation of polyester-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polyethylene adipate were added to the reaction vessel, stirred and heated to 70°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and the prepolymerization reaction was carried out at the temperature for 3 hours. The reaction was then stopped to obtain prepolymer II; (2) 5 parts of hydrophilic chain extender II and 40 parts of acetone were added to prepolymer II, stirred and heated to 70°C, and the chain extension reaction was carried out at the temperature for 2 hours. The reaction was then stopped, and the polyester-type waterborne polyurethane was obtained after separation and purification.

[0058] 5. Add polyether-type waterborne polyurethane, polyester-type waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 22 parts of polyether-type waterborne polyurethane, 15 parts of polyester-type waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water;

[0059] Step 2: Corona treatment is applied to one side of the PET film, and then it is placed on a coating machine and coated at a speed of 300 mm / min, with the coating wet weight controlled at 6 ± 0.2 g / m. 2 Finally, it is dried to obtain a water-based coating layer;

[0060] Step 3: The film obtained in Step 2 is aluminum-coated using a vacuum aluminum plating machine. Under a high vacuum of 0.01 Pa, the aluminum wire is heated to 1400℃ and vaporized. Then, an aluminum plating layer with a thickness of 40 nm is deposited on the water-based coating layer. The aluminum plating layer is then subjected to molding printing and alkaline washing treatment.

[0061] Step 4: Place the film obtained in Step 3 on a coating machine and coat it on the aluminum-coated side at a speed of 300 mm / min, controlling the coating wet weight at 5 ± 0.2 g / m. 2 Finally, a CPP film is applied to obtain a fold-resistant, high-transparency, environmentally friendly water-based transfer membrane.

[0062] Example 3: A method for preparing a fold-resistant, high-transparency, environmentally friendly waterborne transfer membrane:

[0063] Step 1: 1. Preparation of hydrophilic chain extender I: (1) Add 8 parts of DL-cysteine ​​and 0.18 parts of photoinitiator to a reaction vessel containing 6 parts of butenyl glycol. After stirring and dispersing for 10 min, irradiate with 365 nm ultraviolet light for 30 min to obtain product I; (2) Add 20 parts of sodium p-aminobenzenesulfonate, 10 parts of N,N'-dicyclohexylcarboimide and 10 parts of 4-dimethylaminopyridine to 10 parts of product I. Stir and react at 20 °C for 24 h. After the reaction is completed, the hydrophilic chain extender I is obtained by separation and purification.

[0064] 2. Preparation of polyether-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polytetrahydrofuran ether diol were added to the reaction vessel, stirred and heated to 75°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and kept warm for 3 hours for prepolymerization reaction. The reaction was then stopped to obtain prepolymer I; (2) 10 parts of hydrophilic chain extender I and 40 parts of acetone were added to prepolymer I, stirred and heated to 70°C, and kept warm for 2 hours for chain extension reaction. The reaction was then stopped, and after separation and purification, polyether-type waterborne polyurethane was obtained.

[0065] 3. Preparation of hydrophilic chain extender II: (1) Add 1 part of sodium p-aminobenzenesulfonate and 10 parts of 2,4-toluene diisocyanate to a reaction vessel. Under nitrogen protection, heat to 100°C and stir for 18 h. After the reaction is stopped, after the temperature is restored to room temperature, add excess n-pentane, collect the precipitate, wash it three times with n-pentane, and dry it under vacuum at 50°C to obtain product II; (2) Add 6 parts of product II and 3 parts of 2-amino-2-methyl-1,3-propanediol to a reaction vessel containing 10 parts of chloroform. Under nitrogen protection, heat to 60°C and reflux for 18 h. After the reaction is stopped, the hydrophilic chain extender II is obtained by separation and purification.

[0066] 4. Preparation of polyester-type waterborne polyurethane: (1) Under nitrogen protection, 10 parts of polyethylene adipate were added to the reaction vessel, stirred and heated to 70°C, 20 parts of 2,4-toluene diisocyanate and 0.1 parts of dibutyltin dilaurate were added, mixed evenly, and the prepolymerization reaction was carried out at the temperature for 3 hours. The reaction was then stopped to obtain prepolymer II; (2) 10 parts of hydrophilic chain extender II and 40 parts of acetone were added to prepolymer II, stirred and heated to 70°C, and the chain extension reaction was carried out at the temperature for 2 hours. The reaction was then stopped, and the polyester-type waterborne polyurethane was obtained after separation and purification.

[0067] 5. Add polyether-type waterborne polyurethane, polyester-type waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 22 parts of polyether-type waterborne polyurethane, 15 parts of polyester-type waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water;

[0068] Step 2: Corona treatment is applied to one side of the PET film, and then it is placed on a coating machine and coated at a speed of 300 mm / min, with the coating wet weight controlled at 6 ± 0.2 g / m. 2 Finally, it is dried to obtain a water-based coating layer;

[0069] Step 3: The film obtained in Step 2 is aluminum-coated using a vacuum aluminum plating machine. Under a high vacuum of 0.01 Pa, the aluminum wire is heated to 1400℃ and vaporized. Then, an aluminum plating layer with a thickness of 40 nm is deposited on the water-based coating layer. The aluminum plating layer is then subjected to molding printing and alkaline washing treatment.

[0070] Step 4: Place the film obtained in Step 3 on a coating machine and coat it on the aluminum-coated side at a speed of 300 mm / min, controlling the coating wet weight at 5 ± 0.2 g / m. 2 Finally, a CPP film is applied to obtain a fold-resistant, high-transparency, environmentally friendly water-based transfer membrane.

[0071] Based on Example 1, the following control experiments were conducted, specifically Comparative Examples 1 to 5, as described below:

[0072] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustments: polyester-based waterborne polyurethane is not added, and it is replaced with polyether-based waterborne polyurethane, while other processes remain unchanged. Specifically:

[0073] Step 1: Add polyether-type waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 37 parts of polyether-type waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water.

[0074] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustments: no polyether-based waterborne polyurethane is added, and it is replaced with polyester-based waterborne polyurethane, while other processes remain unchanged. Specifically:

[0075] Step 1: Add polyester-type waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water into a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 37 parts of polyester-type waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water.

[0076] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustment: water-based polyacrylate is not added, while other processes remain unchanged. Specifically:

[0077] Step 1: Add polyether-type waterborne polyurethane, polyester-type waterborne polyurethane, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 22 parts of polyether-type waterborne polyurethane, 15 parts of polyester-type waterborne polyurethane, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water.

[0078] Comparative Example 4: Comparative Example 4 is based on Example 1, but the following was adjusted: the amount of water-based coating components was adjusted, while other processes remained unchanged. Specifically:

[0079] The weight proportions of each component of the water-based coating are as follows: 10 parts of polyether-type water-based polyurethane, 10 parts of polyester-type water-based polyurethane, 8 parts of water-based polyacrylate, 0.2 parts of water-based leveling agent, 0.25 parts of water-based defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water.

[0080] Comparative Example 5: Comparative Example 5 is based on Example 1, with the following adjustments: the waterborne polyurethane used is commercially available model HT-1282 waterborne polyurethane, while other processes remain unchanged. Specifically:

[0081] Step 1: Add HT-1282 waterborne polyurethane, waterborne polyacrylate, waterborne leveling agent, alcohol ether ester film-forming aid, waterborne defoamer, and water to a container and mix evenly to obtain a waterborne coating; wherein, the weight parts of each component of the waterborne coating are: 37 parts of HT-1282 waterborne polyurethane, 8 parts of waterborne polyacrylate, 0.2 parts of waterborne leveling agent, 0.25 parts of waterborne defoamer, 2 parts of alcohol ether ester film-forming aid, and 65 parts of water.

[0082] In the above embodiments, all raw materials were sourced as follows: polytetrahydrofuran ether glycol, butene glycol, and N,N'-dicyclohexylcarboimide, all with a purity of 99%, were purchased from Hubei Yongkuo Technology Co., Ltd.; 2,4-toluene diisocyanate, dibutyltin dilaurate, and polyethylene adipate, all with a purity of 99%, were purchased from Shanghai Jinjinle Industrial Co., Ltd.; sodium p-aminobenzenesulfonate and 2-amino-2-methyl-1,3-propanediol, both with a purity of 99%, were purchased from Hebei Zhentian Food Additives Co., Ltd.; waterborne polyacrylate, model LA-6099, was purchased from Zhaoqing Xinguangli Chemical Industry Co., Ltd.; waterborne leveling agent, model PU-202, was purchased from Lugong Additives Co., Ltd.; waterborne defoamer, model DE-H055, was purchased from Yueguan New Materials Co., Ltd.; and HT-1282 waterborne polyurethane was purchased from Hefei Hengtian New Materials Technology Co., Ltd.

[0083] Performance Testing: The folding endurance and adhesion of the high-permeability, environmentally friendly waterborne transfer films prepared in Examples 1-3 and Comparative Examples 1-5 were tested. Adhesion was tested using the 3M tape method after the folding endurance test. Specific test results are shown in Table 1.

[0084] Table 1

[0085]

[0086] Conclusion: Based on the test results in Table 1 above, the folding resistance of the high-transparency, environmentally friendly waterborne transfer film prepared by this invention, except for the commercially available waterborne polyurethane (Comparative Example 5), meets the standard in YC263-2008 (folding resistance > 20 times). No cracking occurs after more than 20 folds, indicating that the waterborne transfer film prepared by this invention has excellent folding resistance. Furthermore, the waterborne coating in this invention exhibits stable performance; after the folding resistance test, the waterborne transfer film prepared in the examples did not show any signs of poor adhesion, further demonstrating the excellent folding resistance of the waterborne transfer film prepared by this invention. In addition, since no volatile organic solvents such as acetone are added to the raw materials, no residue will be left during use. Moreover, the mixing and blending of multiple resins can effectively enhance the film transparency. Finally, this invention yields a high-transparency, environmentally friendly waterborne transfer film with excellent folding resistance.

[0087] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the spirit and principles of the present invention and within the technical scope disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features described in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane, characterized in that: Includes the following steps: Step 1: Add polyether-based waterborne polyurethane, polyester-based waterborne polyurethane, waterborne polyacrylate, leveling agent, film-forming aid, defoamer, and water into a container and mix well to obtain a waterborne coating. Step 2: Perform corona treatment on one side of the substrate, and then apply a water-based coating to that side, controlling the wet weight at 4~8g / m². 2 Drying yields a water-based coating layer; Step 3: Aluminum plating is performed on the water-based coating layer to obtain an aluminum plating layer, and then the aluminum plating layer is subjected to molding printing and alkaline washing; Step 4: Apply a water-based adhesive to the aluminum plating layer, with a wet weight of 3~6g / m². 2 A protective film is applied to obtain a fold-resistant, highly transparent, environmentally friendly water-based transfer membrane. The preparation method of the polyether-type waterborne polyurethane is as follows: (1) Under the protection of inert gas, polyether diol is added to the reaction vessel, stirred and heated to 60~80℃, diisocyanate and catalyst are added, mixed evenly, and kept warm for 2~4h to obtain prepolymer I; (2) hydrophilic chain extender I and organic solvent are added to prepolymer I, stirred and heated to 60~80℃, kept warm for 1~3h, and then separated and purified to obtain polyether-type waterborne polyurethane; wherein, the preparation method of hydrophilic chain extender I is as follows: (1) DL-cysteine ​​and photoinitiator are added to the reaction vessel containing unsaturated diol, stirred and dispersed for 5~15min, and then irradiated with 365nm ultraviolet light for 15~60min to obtain product I; (2) sodium p-aminobenzenesulfonate, condensing agent and 4-dimethylaminopyridine are added to product I, stirred and reacted at 0~40℃ for 12~48h, and then separated and purified to obtain hydrophilic chain extender I; The preparation method of the polyester-type waterborne polyurethane is as follows: (1) Under the protection of inert gas, polyester diol is added to the reaction vessel, stirred and heated to 60~80℃, then diisocyanate and catalyst are added, mixed evenly, and kept at the temperature for 2~4h to stop the reaction and obtain prepolymer II; (2) hydrophilic chain extender II and organic solvent are added to prepolymer II, stirred and heated to 60~80℃, kept at the temperature for 1~3h, and then separated and purified to obtain polyester-type waterborne polyurethane; wherein, the preparation method of hydrophilic chain extender II is as follows: (1) the hydrophilic chain extender II is added to the prepolymer II, stirred and heated to 60~80℃, kept at the temperature for 1~3h, and then separated and purified to obtain polyester-type waterborne polyurethane; wherein, the preparation method of hydrophilic chain extender II is as follows: (1) the hydrophilic chain extender II is added to the reaction vessel and heated to 60~80℃ to stop the reaction and obtain prepolymer II; Sodium aminobenzenesulfonate and diisocyanate were added to the reaction vessel and stirred for 12-24 hours under inert gas protection at 90-100°C. After the temperature was restored to room temperature, excess n-pentane was added, the precipitate was collected, washed several times with n-pentane, and dried under vacuum at 50°C to obtain product II. (2) Product II and 2-amino-2-methyl-1,3-propanediol were added to the reaction vessel containing chloroform and refluxed for 6-24 hours under inert gas protection at 50-70°C. After separation and purification, hydrophilic chain extender II was obtained.

2. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The water-based coating comprises the following components by weight: 10-25 parts of polyether-type water-based polyurethane, 10-25 parts of polyester-type water-based polyurethane, 5-15 parts of water-based polyacrylate, 0.1-0.5 parts of leveling agent, 0.15-0.3 parts of defoamer, 1.5-3.5 parts of film-forming aid, and 40-80 parts of water.

3. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The mass ratio of the polyether diol, diisocyanate, catalyst, and hydrophilic chain extender I is 10:20:0.1:(5~10); the polyether diol includes any one of polytetrahydrofuran ether diol, polypropylene glycol, and polyoxypropylene diol, with a molecular weight of 600~2000; the diisocyanate includes at least one of isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4-toluene diisocyanate, and 4,4'-diphenylmethane diisocyanate; the catalyst is dibutyltin dilaurate or stannous octoate.

4. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The mass ratio of the unsaturated diol and DL-cysteine ​​is 3:4; the amount of photoinitiator added is 2-5% of the mass of the unsaturated diol; the unsaturated diol includes any one of butenyl glycol and 1,4-dihydroxy-2-butene; the mass ratio of product I, sodium p-aminobenzenesulfonate, condensing agent, and 4-dimethylaminopyridine is 1:(1-2):1:1; the condensing agent includes at least one of N,N'-dicyclohexylcarbodiimide, N,N-diisopropylcarbodiimide, 1,3-di(2,2-dimethyl-1,3-dioxolane-4-ylmethyl)carbodiimide, and 1-hydroxybenzotriazole.

5. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 3, characterized in that: The mass ratio of the polyester diol, diisocyanate, catalyst, and hydrophilic chain extender II is 10:20:0.1:(5~10); the polyester diol includes at least one of polyethylene adipate, diethylene glycol oxalate, and neopentyl oxalate, with a molecular weight of 1000~2000; the diisocyanate and catalyst are the same as those used in the preparation method of the polyether-type waterborne polyurethane.

6. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The mass ratio of sodium p-aminobenzenesulfonate and diisocyanate is 1:(5~10); the mass ratio of product II and 2-amino-2-methyl-1,3-propanediol is 2:

1.

7. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The leveling agent is a water-based leveling agent; the defoamer is a water-based defoamer; the film-forming aid includes one or more of the following: alcohol ester film-forming aids, alcohol ether film-forming aids, and alcohol ether ester film-forming aids.

8. The method for preparing a fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane according to claim 1, characterized in that: The specific aluminum plating process of the aluminum plating layer is as follows: under high vacuum conditions of 0.01~0.05Pa, the aluminum wire is heated to 1400℃ and vaporized in a vacuum aluminum plating machine, and then it is attached to the water-based coating layer to form an aluminum plating layer with a thickness of 20~50nm.

9. The fold-resistant, high-permeability, environmentally friendly aqueous transfer membrane prepared by the method according to any one of claims 1 to 8 is characterized in that: The fold-resistant, high-transparency, environmentally friendly water-based transfer membrane is composed of, from bottom to top, a base layer, a water-based coating layer, an aluminum plating layer, an adhesive layer, and a protective layer.

10. The fold-resistant, high-transparency, environmentally friendly waterborne transfer membrane according to claim 9, characterized in that: The base layer includes any one of PET film, PVC film, PETG film, and BOPP film; the water-based coating layer is obtained by applying and drying water-based coating; the adhesive layer is obtained by applying and drying water-based adhesive; and the protective layer is CPP film.

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