A water-based transfer coating, a water-based composite laser transfer film, and a manufacturing process for the laser transfer film.

Abstract

This application relates to the field of packaging materials technology, specifically disclosing a water-based transfer coating, a water-based composite laser transfer film, and a manufacturing process for the laser transfer film. The water-based composite laser transfer film comprises a base layer, a water-based transfer coating, an aluminum plating layer, a water-based polyurethane adhesive layer, and a CPP film layer, stacked sequentially. The water-based transfer coating comprises the following components by weight: 25-40 parts epoxy acrylate resin, 0.5-1.5 parts graphene, 1.2-1.75 parts co-solvent, 0.4-0.7 parts antioxidant, 0.25-0.45 parts defoamer, 3-5 parts sodium dodecyl sulfate, 0.2-0.5 parts preservative, and 44-67 parts water. By adding graphene to the water-based transfer coating, this application achieves a water-based transfer coating with better water-repellent properties, thereby hindering the contact between the aluminum plating layer and water molecules, reducing the possibility of corrosion and peeling of the aluminum plating layer, and improving the long-term performance of the laser transfer film.

Description

Technical Field

[0001] This application relates to the field of packaging materials technology, and more specifically, it relates to a water-based transfer coating, a water-based composite laser transfer film, and a manufacturing process for the laser transfer film. 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 primarily use organic solvents for laminating the film to the substrate, which leads to the diffusion of volatile solvents into the atmosphere, causing environmental pollution and posing certain safety hazards.

[0003] One related technology is an aqueous composite laser transfer film, comprising a base layer, an aqueous transfer coating, an aluminum plating layer, an aqueous polyurethane adhesive layer, and a CPP film layer stacked sequentially. The base layer is a PET film, and the aqueous transfer coating is obtained by baking and curing the aqueous transfer coating. The aqueous transfer coating comprises the following components in parts by weight: 25 parts epoxy acrylate resin, 1.2 parts cosolvent, 0.4 parts antioxidant, 0.25 parts defoamer, 3 parts sodium dodecyl sulfate, 0.2 parts preservative, and 44 parts water.

[0004] Regarding the aforementioned technologies, the inventors believe that although water-based transfer coatings have been implemented, epoxy acrylate resins have good hydrophilicity, making them prone to moisture absorption after film formation. Under humid and hot conditions, the aluminum plating layer in these technologies will corrode, easily causing it to detach from the surface of the water-based transfer coating, which is detrimental to improving the long-term performance of the laser transfer film. Summary of the Invention

[0005] In related technologies, the aluminum plating layer corrodes under humid and hot conditions, easily causing it to detach from the surface of the water-based transfer coating, which is detrimental to improving the long-term performance of the laser transfer film. To overcome this deficiency, this application provides a water-based transfer coating, a water-based composite laser transfer film, and a manufacturing process for the laser transfer film.

[0006] In a first aspect, this application provides a water-based transfer coating, which adopts the following technical solution:

[0007] A water-based transfer coating comprises the following components in parts by weight: 25-40 parts epoxy acrylate resin, 0.5-1.5 parts graphene, 1.2-1.75 parts cosolvent, 0.4-0.7 parts antioxidant, 0.25-0.45 parts defoamer, 3-5 parts sodium dodecyl sulfate, 0.2-0.5 parts preservative, and 44-67 parts water.

[0008] By adopting the above technical solution, this application incorporates graphene into the waterborne transfer coating. Graphene is a two-dimensional sheet-like nanomaterial that is fixed within the waterborne transfer coating during curing and hinders the migration of water molecules through its sheet-like structure. Simultaneously, graphene can fill micropores and defects in the waterborne transfer coating, increasing its density and reducing the resistance that water molecules must overcome to penetrate it. By adding graphene to the waterborne transfer coating, a waterborne transfer coating with better water-repellent properties can be obtained, thereby hindering contact between the aluminum plating layer and water molecules, reducing the possibility of corrosion and peeling of the aluminum plating layer, and improving the long-term performance of the laser transfer film.

[0009] Preferably, the waterborne transfer coating further comprises 1-1.5 parts by weight of N-hydroxymethylacrylamide.

[0010] By adopting the above technical solution, N-hydroxymethylacrylamide has self-crosslinking properties. During the baking and curing process of waterborne transfer coatings, it can form crosslinking products with a certain molecular weight through self-crosslinking, thereby improving the density of the waterborne transfer coating after film formation. This helps to improve the water-proof properties of the waterborne transfer coating, hinders the contact between the aluminum plating layer and water molecules, and reduces the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0011] Preferably, the water-based transfer coating also includes a waterproof filler, which is activated carbon powder with a polyurea shell coating on its surface.

[0012] By adopting the above technical solution, the polyurea shell layer on the surface of the waterproof filler has good water-repellency and weather resistance. When the waterproof filler is added to the water-based transfer coating, it works together with graphene to provide water repellency, improving the water-repellency of the water-based transfer coating and hindering contact between the aluminum plating layer and water molecules. Simultaneously, the waterproof filler also provides a certain degree of roughness to the surface of the water-based transfer coating, which is beneficial for the full bonding between the aluminum plating layer and the water-based transfer coating, thereby reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0013] Preferably, the waterproof filler is prepared according to the following method:

[0014] (1) Mix water, activated carbon powder, surfactant and polyvinyl alcohol and stir to obtain a filler dispersion for later use; stir and mix diisocyanate and toluene to obtain an isocyanate solution and keep it warm for later use.

[0015] (2) The filler dispersion was added to the isocyanate solution under heating conditions. The resulting mixture was kept warm and amine curing agent and dibutyltin dilaurate were added. After stirring, the solid particles in the mixture were recovered. After washing and drying, the waterproof filler was obtained.

[0016] By adopting the above technical solution, this application first prepares a filler dispersion and an isocyanate solution, respectively. Then, in the presence of an amine curing agent, the filler dispersion and the isocyanate solution are mixed. The diisocyanate reacts with the amine curing agent to form a polyurea, which coats the surface of the activated carbon powder to form a polyurea shell. After washing and drying, a waterproof filler is obtained. During the reaction process, the reaction rate between the amine curing agent and the isocyanate groups is much higher than the reaction rate between water and the isocyanate groups, thus significantly reducing the occurrence of side reactions.

[0017] Preferably, the activated carbon powder has an average particle size of 1.2-1.8 μm.

[0018] By adopting the above technical solution, the particle size range of activated carbon powder was optimized. Within this particle size range, the waterproof filler prepared using activated carbon powder can effectively improve the surface roughness of the water-based transfer coating, thereby improving the water-proof performance of the water-based transfer coating and reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0019] Preferably, the amount of the waterproof filler is 5-9% of the weight of the epoxy acrylate resin.

[0020] By adopting the above technical solution, the amount of waterproof filler is optimized, which helps to improve the water-proof performance of the water-based transfer coating, hinders the contact between the aluminum plating layer and water molecules, and reduces the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0021] Secondly, this application provides an aqueous composite laser transfer film, which adopts the following technical solution.

[0022] A water-based composite laser transfer film includes a base layer, a water-based transfer coating, an aluminum-plated layer, a water-based polyurethane adhesive layer, and a CPP film layer stacked sequentially. The base layer is a PET film, and the water-based transfer coating is obtained by baking and curing any of the above-mentioned water-based transfer coatings.

[0023] By adopting the above technical solution, the water-based transfer coating of this application has good water-repellent properties, thus reducing the contact between the aluminum plating layer surface and water molecules, thereby reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0024] Thirdly, this application provides a manufacturing process for a laser transfer film, which adopts the following technical solution.

[0025] A manufacturing process for an aqueous composite laser transfer film includes the following steps:

[0026] (1) Select PET film as the base layer;

[0027] (2) Apply any of the above-mentioned water-based transfer coatings to the surface of the substrate layer using a coating machine, and then bake to form a water-based transfer coating on the surface of the substrate layer.

[0028] (3) Vacuum aluminum plating is performed on the surface of the water-based transfer coating to obtain an aluminum plating layer;

[0029] (4) Perform embossing printing on the surface of the aluminum plating layer to form an embossed pattern on the surface of the aluminum plating layer;

[0030] (5) The aluminum-plated layer is washed in an alkaline bath;

[0031] (6) The aluminum-plated layer and the CPP film layer are bonded together with water-based polyurethane adhesive to obtain a water-based composite laser transfer film.

[0032] By adopting the above technical solution, this application uses PET film as a substrate and sequentially laminates a water-based transfer coating, an aluminum plating layer, a water-based polyurethane adhesive layer, and a CPP film layer on the surface of the substrate to obtain a water-based composite laser transfer film.

[0033] Preferably, the water-based transfer coating comprises waterproof fillers, and in step (2) of the production process, the coating amount of the water-based transfer coating on the substrate surface is 1.0-1.2 g / m². 2 .

[0034] By adopting the above technical solution, the coating amount of the water-based transfer coating was optimized. According to this coating amount, the waterproof filler can fully improve the surface roughness of the water-based transfer coating, which helps to reduce the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0035] Preferably, in step (4) of the production process, the embossing pressure is 0.3-0.5 MPa.

[0036] By adopting the above technical solution, the pressure range used during molding printing is optimized, which helps to ensure full contact between the aluminum plating layer and the water-based transfer coating, allowing the water-based transfer coating to fully exert its water-repellent effect and reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. This application achieves a water-based transfer coating with good water-repellent properties by adding graphene to the water-based transfer coating, thereby hindering the contact between the aluminum plating layer and water molecules, reducing the possibility of corrosion and peeling of the aluminum plating layer, and improving the long-term performance of the laser transfer film.

[0039] 2. This application utilizes the synergistic effect of waterproof fillers and graphene to improve the water-repellent properties of the water-based transfer coating, hindering the contact between the aluminum plating layer and water molecules. Simultaneously, the waterproof fillers also provide a certain degree of roughness to the surface of the water-based transfer coating, which facilitates the full bonding between the aluminum plating layer and the water-based transfer coating, thereby reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments, preparation examples and comparative examples. The raw materials involved in the present application can all be obtained commercially.

[0041] Preparation example of waterproof filler

[0042] The following explanation uses Preparation Example 1 as an example.

[0043] Preparation Example 1

[0044] In this preparation example, the waterproof filler is prepared according to the following method:

[0045] (1) Water, activated carbon powder, surfactant and polyvinyl alcohol are mixed in a weight ratio of 50:5:0.1:2.5 and stirred at 1300 r / min for 40 min to obtain a filler dispersion for later use; diisocyanate and toluene are mixed in a weight ratio of 3:100 and stirred at 1000 r / min for 1 h to obtain an isocyanate solution, which is kept at 75℃ for later use; the surfactant is n-octanol, the polyvinyl alcohol is type 1788, the average particle size of activated carbon powder is 0.8 μm, the diisocyanate is TDI, and the weight ratio of diisocyanate to activated carbon powder is 3:5;

[0046] (2) The filler dispersion was added to the isocyanate solution under heating conditions. The resulting mixture was kept at 75°C. An amine curing agent and dibutyltin dilaurate were added. After stirring at 1000 r / min for 4 h, the solid particles in the mixture were recovered. After washing and drying, the waterproof filler was obtained. The amine curing agent was diethylenetriamine. The weight ratio of the amine curing agent, dibutyltin dilaurate and the activated carbon powder used in step (1) was 1:1:10.

[0047] As shown in Table 1, the difference between preparation examples 1-5 lies in the average particle size of the activated carbon powder.

[0048] Table 1 Average particle size of activated carbon powder

[0049]

[0050]

[0051] Example

[0052] Examples 1-5

[0053] The following description uses Example 1 as an example.

[0054] Example 1

[0055] This embodiment provides a water-based transfer coating comprising the following components: 25 kg of epoxy acrylate resin, 0.5 kg of graphene, 1.2 kg of co-solvent, 0.4 kg of antioxidant, 0.25 kg of defoamer, 3 kg of sodium dodecyl sulfate, 0.2 kg of preservative, and 44 kg of water. The epoxy acrylate resin is model EA1279A, the graphene has the CAS number 1034343-98-0, the co-solvent is ethylene glycol monobutyl ether, the preservative is nano zinc oxide, the defoamer is BYK defoamer, and the antioxidant is butylated hydroxytoluene.

[0056] This embodiment also provides an aqueous composite laser transfer film, comprising a base layer, an aqueous transfer coating, an aluminum plating layer, an aqueous polyurethane adhesive layer, and a CPP film layer stacked sequentially. The base layer is a PET film with a thickness of 22 μm and a surface tension of 37 dyn, the aluminum plating layer has a thickness of 300 μm, and the CPP film layer has a thickness of 30 μm.

[0057] This embodiment also provides a method for preparing a laser transfer film, including the following steps:

[0058] (1) Select PET film as the base layer;

[0059] (2) Apply a coating to the substrate surface using a coating machine at a speed of 90 m / min at a concentration of 3.5 g / m 2 Apply water-based transfer coating at a certain coating amount, and then bake at 95°C for 15 seconds to form a water-based transfer coating on the substrate surface.

[0060] (3) Vacuum aluminum plating was performed on the surface of the water-based transfer coating to obtain an aluminum plating layer with a thickness of 300 μm;

[0061] (4) At 170°C, embossing is performed on the surface of the aluminum-plated layer at a rate of 45 m / min and an embossing pressure of 0.1 MPa to form an embossed pattern on the surface of the aluminum-plated layer.

[0062] (5) The aluminum plating layer is washed in an alkaline bath at 60°C at a machine speed of 45 m / min, and then dried at 60°C.

[0063] (6) The aluminum-plated layer and the CPP film layer were bonded together with a water-based polyurethane adhesive at 70℃ to obtain a water-based composite laser transfer film. The dry adhesive weight of the water-based polyurethane adhesive was 3.2 g / m³. 2 .

[0064] As shown in Table 2, the main difference between Examples 1-5 lies in the different raw material ratios of the water-based transfer coatings.

[0065] Table 2 Raw material ratios for waterborne transfer coatings

[0066]

[0067]

[0068] Example 6

[0069] The difference between this embodiment and Embodiment 5 is that the water-based transfer coating also includes 0.5 kg of N-hydroxymethylacrylamide.

[0070] As shown in Table 3, the difference between Examples 6-10 is the amount of N-hydroxymethylacrylamide used.

[0071] Table 3 Dosage of N-hydroxymethylacrylamide

[0072] sample Example 6 Example 7 Example 8 Example 9 Example 10 N-hydroxymethylacrylamide / kg 0.5 0.8 1 1.2 1.5

[0073] Example 11

[0074] The difference between this embodiment and Example 10 is that the water-based transfer coating also includes a waterproof filler, the amount of which is 1% of the weight of the epoxy acrylic resin, and the waterproof filler is prepared according to the method of Preparation Example 1.

[0075] As shown in Table 4, the difference between Examples 11-15 lies in the different preparation methods of the waterproof filler.

[0076] Table 4 Examples of Waterproofing Filler Preparation

[0077] sample Example 11 Example 12 Example 13 Example 14 Example 15 Preparation Example Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5

[0078] As shown in Table 5, the difference between Examples 15-19 is that the percentage of waterproof filler used in the epoxy acrylic resin (hereinafter referred to as the waterproof filler percentage) is different.

[0079] Table 5. Proportion of Waterproofing Filler

[0080] sample Example 15 Example 16 Example 17 Example 18 Example 19 Waterproof filler percentage / % 1 3 5 7 9

[0081] As shown in Table 6, the difference between Examples 19-23 is that the amount of water-based transfer coating applied to the substrate surface is different.

[0082] Table 6. Coating amount of water-based transfer coating on the substrate surface

[0083]

[0084] As shown in Table 7, the difference between implementations 23-27 is that the embossing pressure in step (4) of the process for producing laser transfer film is different.

[0085] Table 7 Imprint Pressure

[0086] sample Example 23 Example 24 Example 25 Example 26 Example 27 Imprint pressure / MPa 0.1 0.2 0.3 0.4 0.5

[0087] Comparative Example

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 1 is that the water-based transfer coating does not include graphene.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is that the weight of graphene in the water-based transfer coating component is 0.3 kg.

[0092] Performance testing methods

[0093] Accelerated damp heat aging tests were conducted using a Ci3000+ xenon lamp weathering tester (ATLAS, USA). The test conditions were 50°C and RH = 95%. The laser transfer films of each embodiment and comparative example were cut into rectangular samples of 12cm × 5cm. Accelerated aging was carried out under the test conditions. The time from when the aluminum plating layer of the sample began to peel off from the surface of the water-based transfer coating was detected and recorded as the peeling time t (in minutes). Then, the ratio between the peeling time of each embodiment and comparative example and the peeling time of Comparative Example 1 was calculated, and this ratio was recorded as the relative peeling time. The results are shown in Table 8.

[0094] Table 8 Relative Shedding Time

[0095]

[0096]

[0097] Combining Examples 1-5 and Comparative Examples 1-2 with Table 8, it can be seen that the relative detachment times measured in Examples 1-5 are all greater than those in Comparative Examples 1-2. This indicates that only when the water-based transfer coating contains graphene and the amount of graphene reaches the lower limit specified in this application can graphene play a more sufficient role in improving the water-based transfer coating, thereby reducing the erosion of the aluminum plating layer in a humid and hot environment, delaying the detachment of the aluminum plating layer, and improving the long-term performance of the laser transfer film.

[0098] As can be seen from Examples 5 and 6-10 and Table 8, the addition of N-hydroxymethylacrylamide can delay the time of aluminum plating layer peeling off under humid and hot conditions, indicating that N-hydroxymethylacrylamide can reduce the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions. When the amount of N-hydroxymethylacrylamide is 1-1.5 parts by weight, the peeling off of the aluminum plating layer is relatively delayed.

[0099] As can be seen from Examples 10 and 11-15 and Table 8, the addition of waterproof filler can delay the detachment of the aluminum plating layer. This indicates that the waterproof filler can hinder the contact between the aluminum plating layer and water molecules, and gives the surface of the water-based transfer coating a certain roughness, which is conducive to the full bonding of the aluminum plating layer and the water-based transfer coating, reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions. When the average particle size of the activated carbon powder used to prepare the waterproof filler is 1.2-1.8 μm, the water-repellent performance of the water-based transfer coating is better, and correspondingly, the aluminum plating layer is less likely to detach in a humid and hot environment.

[0100] As can be seen from Examples 15-19 and Table 8, when the amount of waterproof filler is 5-9% of the weight of epoxy acrylic resin, the water-based transfer coating has good water-proof performance, so the aluminum plating layer is not easy to peel off in a humid and hot environment.

[0101] Referring to Examples 19-23 and Table 8, it can be seen that when the water-based transfer coating contains waterproof fillers, setting the coating amount of the water-based transfer coating on the substrate surface to 1.0-1.2 g / m² is effective. 2 It can significantly improve the surface roughness of the water-based transfer coating through waterproof fillers, thereby improving the bonding effect between the aluminum plating layer and the water-based transfer coating, and helping to reduce the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0102] As can be seen from Examples 23-27 and Table 8, when the embossing pressure is 0.3-0.5 MPa, the aluminum plating layer peels off relatively late. This indicates that the embossing pressure set within this range helps to ensure sufficient contact between the aluminum plating layer and the water-based transfer coating, allowing the water-based transfer coating to fully exert its water-repellent effect and reducing the possibility of corrosion and peeling of the aluminum plating layer under humid and hot conditions.

[0103] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An aqueous composite laser transfer film, characterized in that, The water-based composite laser transfer film comprises a base layer, a water-based transfer coating, an aluminum plating layer, a water-based polyurethane adhesive layer, and a CPP film layer stacked sequentially. The base layer is a PET film, and the water-based transfer coating is obtained by baking and curing the water-based transfer coating. The water-based transfer coating comprises the following components in parts by weight: 25-40 parts epoxy acrylate resin, 0.5-1.5 parts graphene, 1.2-1.75 parts co-solvent, 0.4-0.7 parts antioxidant, 0.25-0.45 parts defoamer, 3-5 parts sodium dodecyl sulfate, 0.2-0.5 parts preservative, and 44-67 parts water; wherein the co-solvent is ethylene glycol monobutyl ether, the antioxidant is butylated hydroxytoluene, the defoamer is BYK defoamer, and the preservative is nano zinc oxide; The water-based transfer coating also includes a waterproof filler, which is activated carbon powder with a polyurea shell coating on its surface; the waterproof filler is prepared according to the following method: (1) Mix water, activated carbon powder, surfactant and polyvinyl alcohol and stir to obtain a filler dispersion for later use; stir and mix diisocyanate and toluene to obtain an isocyanate solution and keep it warm for later use. (2) The filler dispersion was added to the isocyanate solution under heating conditions. The resulting mixture was kept warm and amine curing agent and dibutyltin dilaurate were added. After stirring, the solid particles in the mixture were recovered. After washing and drying, the waterproof filler was obtained. The surfactant is n-octanol; the amine curing agent is diethylenetriamine; The water-based transfer coating also includes 1-1.5 parts by weight of N-hydroxymethylacrylamide; The average particle size of the activated carbon powder is 1.2-1.8 μm; The amount of the waterproof filler is 5-9% of the weight of the epoxy acrylic resin.

2. A manufacturing process for a laser transfer film, characterized in that, Includes the following steps: (1) Select PET film as the base layer; (2) Apply the water-based transfer coating of claim 1 to the surface of the substrate layer using a coating machine, and then bake it to form a water-based transfer coating on the surface of the substrate layer. (3) Vacuum aluminum plating is performed on the surface of the water-based transfer coating to obtain an aluminum plating layer; (4) Perform embossing printing on the surface of the aluminum plating layer to form an embossed pattern on the surface of the aluminum plating layer; (5) The aluminum-plated layer is washed in an alkaline bath; (6) The aluminum-plated layer and the CPP film layer are bonded together with water-based polyurethane adhesive to obtain a water-based composite laser transfer film.

3. The production process of the laser transfer film according to claim 2, characterized in that, The water-based transfer coating comprises waterproof fillers, and in step (2) of the production process, the coating amount of the water-based transfer coating on the substrate surface is 1.0-1.2 g / m². 2 .

4. The production process of the laser transfer film according to claim 2, characterized in that, In step (4) of the production process, the embossing pressure of the molding printing is 0.3-0.5 MPa.

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