Transfer printing label and transfer printing method thereof

Abstract

The invention provides a transfer printing label which sequentially comprises a flexible base material layer, a release layer, a glue layer, a pattern layer, a protective film layer and a transfer film, and the glue layer comprises at least one adhesive which has viscosity at normal temperature and can be cured at high temperature or under the UV condition. The transfer printing method of the transfer printing label comprises the steps that the release layer and the flexible base material layer are separated, and the glue layer is exposed; applying an external force to press the glue layer on the surface of the printing stock to finish initial adhesion, and removing the transfer film at the same time; and the printing stock subjected to initial adhesion is moved into a baking box or a UV box to be subjected to thermocuring or UV curing, and after the adhesive is cured and cooled, the transfer printing procedure is completed. Initial adhesion transfer printing does not need heating or waiting for self-drying, compared with water transfer printing and heat transfer printing processes, the transfer printing speed is higher, and high-speed automatic production is achieved through roll material printing, roll material attaching and assembly line heating and curing.

Description

Technical Field

[0001] The present invention relates to the field of printing technology, and in particular to a transfer label and a transfer method for the transfer label. Background Art

[0002] A transfer label refers to a pattern that has been printed on a transfer film. Through a specific method, the pattern layer leaves the transfer film as a whole and is transferred to a substrate, and then a physical method is selected to cure the pattern layer. Just like direct printing, the pattern composed of ink is cured on the substrate. According to the different media used during transfer, the current transfer methods are divided into two types: water transfer and thermal transfer.

[0003] Water transfer is a process method that uses water as a medium to transfer a pattern to a substrate. The specific process includes: First, cut out the required pattern, put the cut sticker into water for about 10 seconds, and the mask and the base paper will automatically separate; take out the sticker and place it at the position to be transferred, fix the pattern and drag out the base paper, wipe off the moisture with a cloth or tissue paper, and for large areas, a rubber squeegee can be used to discharge the air bubbles and moisture under the face paper, and then leave it to dry naturally; after completely drying naturally, put it into an oven for heating, and the temperature and time depend on different materials, and finally the finished product is completed. Thermal transfer is a process in which a rubber roller is heated to about 180 degrees, the release layer loses its adhesion, the hot melt adhesive layer generates viscosity, the pattern layer and the release coating separate, and the pattern layer is transferred (adhered) to the substrate as a whole through the hot melt adhesive layer.

[0004] Currently, water transfer mainly has problems such as low efficiency and environmental unfriendliness. First of all, the water-soluble coating on the surface of the base paper of the water sticker contains chemical materials such as plasticizers. Dissolving the coating causes water pollution of the medium, and the used water cannot be directly discharged and is industrial wastewater. Secondly, the initial adhesion process with water as the medium is slow and inefficient. The initial adhesion of the water sticker transfer process is that the transfer film is initially adhered to the object through water, then the rubber squeegee drains the water, and then it is left to dry. The moisture in the bonding area slowly evaporates to form a vacuum, thereby completing the initial adhesion of the transfer film. After manual pasting in winter, it takes at least 12 hours overnight to enter the next process. In addition, water transfer usually requires manual operation, with a large number of workers, and the economic benefits of enterprises are low.

[0005] Thermal transfer, on the other hand, mainly has problems such as high energy consumption, low speed of establishing initial adhesion, and low automation efficiency. Thermal transfer is completed through heat. The heat is sequentially transferred from the source (heating rubber roller) to the base film, release coating, pattern layer, hot melt adhesive layer until the hot melt adhesive layer softens. During actual operation on substrates such as glass bottles, since glass absorbs heat, it directly affects the heating rate, thereby reducing the transfer speed. The glass bottle needs to be preheated to complete industrial transfer. In addition, since the base film of thermal transfer is plastic, if the thickness is large, the heat conduction is slow, and if it is thin, it is easily deformed by heat, resulting in pattern deformation. Summary of the Invention

[0006] The present invention aims to provide a transfer label, as well as a transfer method and application of the transfer label, so as to solve the above-mentioned defects existing in the background technology.

[0007] The present invention is implemented by adopting the following technical solutions:

[0008] A transfer label sequentially includes a flexible substrate layer, a release layer, an adhesive layer, a pattern layer, a protective film layer and a transfer film. The adhesive layer contains at least one adhesive that has adhesiveness at normal temperature and can be cured under high temperature or UV conditions.

[0009] The dynamic viscosity of the adhesive at normal temperature is 0.01 - 12 Pa·s. Specifically, it is adjusted according to different printing methods. For example, the dynamic viscosity suitable for screen printing is 3 - 12 Pa·s, the one suitable for flexographic printing is 0.09 - 0.3 Pa·s, the one suitable for gravure printing is 0.01 - 0.2 Pa·s, and the one suitable for inkjet printing is 1 - 10 Pa·s.

[0010] Preferably, the adhesive can be specifically selected from at least one of epoxy resin, acrylic resin or polyurethane resin, such as AG80 epoxy resin, YD-J-1 epoxy acrylate adhesive of Shanghai Yinding Printing Materials Co., Ltd., and OE-SJ-003 waterborne polyurethane adhesive of Shanghai Ouyi Organic Optoelectronic Materials Co., Ltd. Of course, common functional additives in the art, such as tackifiers, plasticizers, stabilizers, antibacterial agents, flame retardants, etc., can be further added to the adhesive to improve or increase certain functions of the adhesive layer and broaden the application scenarios.

[0011] The present invention uses an adhesive that has adhesiveness at normal temperature and can be cured under high temperature or UV conditions as the adhesive layer, and at the same time designs a brand-new transfer label structure. When the transfer label is printed, the adhesive layer pseudo-attaches to the release layer. After tearing off the flexible substrate layer and the release layer during the transfer operation, the label is integrally (together with the protective film layer, the pattern layer and the adhesive layer) transferred and adhered to the substrate under pressure at normal temperature, initially playing the role of adhesion. Subsequently, the adhesive layer is cured by high-temperature heating or UV curing to complete the transfer.

[0012] The protective film layer is a UV or thermosetting varnish, which has good weather resistance, certain hardness and anti-friction property, and plays a role in encapsulating and protecting the pattern layer.

[0013] The transfer film is a low-viscosity film or an electrostatic film, which is laminated on the protective film layer. The transfer film is combined with the protective film layer through low adhesion or electrostatic adsorption. The bonding force between the transfer film and the protective film layer should be greater than the bonding force between the glue layer and the release layer, so that the flexible substrate layer and the release layer can be smoothly removed during the transfer process. When the glue layer has initial adhesion to the printing substrate, the bonding force between the glue layer and the printing substrate should be greater than the bonding force between the protective film layer and the transfer film, so as to remove the transfer film synchronously during the initial adhesion process. The transfer film can be recycled and reused after the transfer is completed.

[0014] The flexible substrate layer can adopt common materials in the art, such as but not limited to paper, plastic film, etc.

[0015] The release layer can adopt common materials in the art, such as but not limited to silicone oil coating, PE film, etc.

[0016] The pattern layer can be ink or hot stamping, such as white, red and other color inks, or cold hot stamping, laser film, etc.

[0017] Preferably, there is also an isolation layer between the glue layer and the pattern layer. The isolation layer is used to isolate the glue layer from the pattern layer and can adopt thermosetting or UV-curable functional varnish, which isolates the sticky glue layer and provides a basic working surface for the printing of the pattern layer.

[0018] The present invention further provides a transfer method for the above transfer label, including the following steps:

[0019] S1. Separate the release layer and the flexible substrate layer to expose the glue layer;

[0020] S2. Apply an external force to press the glue layer onto the surface of the printing substrate to complete the initial adhesion, and at the same time remove the transfer film;

[0021] S3. Move the printing substrate with the initial adhesion into an oven or a UV box for heat curing or UV curing. After the adhesive is cured and cooled, the transfer process is completed.

[0022] As a preferred technical solution, in step S2, the glue layer is pressed onto the surface of the printing substrate by means of a pressure roller rolling or a flexible elastomer pressing. The flexible elastomer can adopt materials such as silica gel.

[0023] Since the bonding force between the glue layer and the printing substrate is greater than the bonding force between the protective film layer and the transfer film, the transfer film can be smoothly removed from the protective film layer during the initial adhesion. When using a pressure roller for the initial adhesion operation, as the pressure roller rotates, the transfer film leaves the protective film layer synchronously.

[0024] Preferably, the release layer and the flexible substrate layer are recycled through a substrate take-up reel, and the transfer film is recycled through a transfer film take-up reel.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention does not require water as a medium and is environmentally friendly and pollution-free compared to the water transfer printing process. The manual full load of water transfer printing is 600 per day, while the present invention can achieve 9,000 transfers per hour, greatly improving the transfer efficiency.

[0027] 2. Compared with self-adhesive labels, the present invention only transfers patterns and does not require a backing paper, saving materials. The glue layer is finally cured on the substrate, irreversible, alcohol-resistant and water-resistant, with a bonding force much greater than that of self-adhesive labels, and excellent weather resistance.

[0028] 3. The initial adhesion transfer does not require heating and has a faster transfer speed compared to the thermal transfer printing process. Traditional thermal transfer is limited by the heat absorption of the substrate, resulting in a slow transfer speed. For example, for the same material, thermal transfer can complete 20 per minute, while the initial adhesion transfer of the present invention can complete 150 per minute. In addition, the present invention has a wider scope of application. For example, the adhesion of wax powder, pearlescent mica powder, etc. to hot melt adhesives is poor, while the glue layer used in the present invention has high adhesion.

[0029] 4. The present invention can achieve high-speed automated production through roll-to-roll printing, roll-to-roll laminating, and in-line heating and curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the transfer label of the present invention.

[0031] Figure 2 It is a schematic process flow diagram of the transfer of the present invention.

[0032] In the figure: 1 - flexible substrate layer; 2 - release layer; 3 - glue layer; 4 - isolation layer; 5 - pattern layer; 6 - protective film layer; 7 - transfer film; 8 - substrate take-up reel; 9 - substrate; 10 - transfer film take-up reel; 11 - pressure roller. DETAILED DESCRIPTION OF THE INVENTION

[0033] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples and do not limit the scope of the present invention. Those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent schemes, and other technical schemes that do not depart from the spirit and scope of the present invention.

[0034] For the equipment or raw materials in the embodiments of the present invention that are not specified by the manufacturer, they are all conventional commercial equipment or raw materials. Among them, the glue layer uses YD-J-1 epoxy acrylate glue of Shanghai Yinding Printing Materials Co., Ltd., the flexible substrate layer uses 33-micron PET film, the release layer uses a silicone oil coating, the isolation layer uses a thermosetting varnish, the pattern layer uses UV color ink, the protective film layer uses a thermosetting varnish, and the transfer film uses a low-viscosity protective film or an electrostatic film.

[0035] Example 1

[0036] A typical transfer label of the present invention is as follows Figure 1 shown, successively including a flexible substrate layer 1, a release layer 2, an adhesive layer 3, an isolation layer 4, a pattern layer 5, a protective film layer 6, and a transfer film 7.

[0037] The transfer label of the present invention can be manufactured by two methods: direct printing or reverse printing, specifically as follows:

[0038] Direct printing process:

[0039] 1. Print (coat) the release layer on the flexible substrate;

[0040] 2. Print the adhesive layer on the release layer;

[0041] 3. Print the isolation layer on the adhesive layer;

[0042] 4. Print the pattern layer on the isolation layer;

[0043] 5. Print the protective film layer on the pattern layer;

[0044] 6. Composite the transfer film.

[0045] Reverse printing process:

[0046] 1. Print the protective film layer on the transfer film;

[0047] 2. Print the pattern layer on the protective film layer;

[0048] 3. Print the isolation layer on the pattern layer;

[0049] 4. Print the adhesive layer on the isolation layer;

[0050] 5. Composite the flexible substrate with a release layer.

[0051] In this example, the transfer label is manufactured by the direct printing process, and the transfer film uses a low-viscosity protective film.

[0052] Example 2

[0053] The typical transfer process of the transfer label of the present invention is as follows Figure 2 shown. In this example, the transfer label has no isolation layer, and the transfer film uses an electrostatic film. Its preparation process refers to Example 1, and the printing step of the isolation layer can be omitted. Specifically, it includes the following steps:

[0054] 1. Separate the release layer 2 and the flexible substrate layer 1 to expose the adhesive layer 3. The release layer and the flexible substrate layer are recycled through the substrate take-up reel 8;

[0055] 2. The glue layer 3 is pressed onto the surface of the substrate 9 by means of rolling with the pressure roller 11 to complete the initial adhesion. The glue layer 3, together with the pattern layer 5 and the protective film layer 6, adheres to the surface of the substrate. Since the bonding force between the glue layer and the substrate is greater than the bonding force between the protective film layer and the transfer film, as the pressure roller rotates, the transfer film synchronously leaves the protective film layer and is recycled through the transfer film take-up reel 10.

[0056] 3. The substrate 9 after the initial adhesion is moved into an oven, and the temperature is raised to the heat setting temperature of 180 °C of the glue layer. After the adhesive is cured and cooled, the transfer process is completed.

[0057] The transfer film is combined with the protective film layer through electrostatic adsorption. The bonding force between the transfer film and the protective film layer is greater than the bonding force between the glue layer and the release layer, and the flexible substrate layer and the release layer can be smoothly removed during the transfer process. When the glue layer is initially adhered to the substrate, the bonding force between the glue layer and the substrate should be greater than the bonding force between the protective film layer and the transfer film, and the transfer film can be removed synchronously during the initial adhesion process. The flexible substrate layer, the release layer, and the transfer film can be recycled and reused after the transfer is completed.

[0058] The initial adhesion transfer of the present invention does not require heating. Through roll-to-roll printing, roll-to-roll laminating, and in-line heat curing, high-speed automated production is achieved. The transfer speed is fast, the efficiency is high, and it is environmentally friendly and pollution-free.

[0059] Those skilled in the art should understand that the above embodiments are only examples and do not limit the present invention. The object of the present invention has been completely and effectively achieved. The functions and principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the said principles, the embodiments of the present invention can have any deformation or modification.

Claims

1. A transfer label, characterized in that: The invention comprises a flexible substrate layer, a release layer, a glue layer, a pattern layer, a protective film layer and a transfer film in sequence, wherein the glue layer comprises at least one adhesive which is sticky at room temperature and curable under high temperature or UV conditions.

2. The transfer label according to claim 1, characterized in that: The adhesive is selected from at least one of epoxy resin, acrylic resin or polyurethane resin.

3. The transfer label according to claim 2, characterized in that: The adhesive is AG80 epoxy resin, YD-J-1 epoxy acrylic adhesive or OE-SJ-003 water-based polyurethane adhesive.

4. The transfer label according to claim 1, characterized in that: The transfer film is a low-viscosity film or an electrostatic film.

5. The transfer label according to claim 1, characterized in that: The flexible substrate layer is selected from any one of paper and plastic film; the release layer is a silicone oil coating or a PE film; and the protective film layer is a UV or thermosetting varnish.

6. The transfer label according to claim 1, characterized in that: There is also an isolation layer between the glue layer and the pattern layer.

7. The transfer label according to claim 1, characterized in that: The isolation layer is UV or thermosetting varnish.

8. The transfer method of the transfer label according to any one of claims 1 to 7, characterized in that: The steps include: S1, separating the release layer and the flexible substrate layer to expose the glue layer; S2, applying external force to press the glue layer onto the surface of the substrate to complete the initial adhesion, and at the same time remove the transfer film; S3, the substrate after the initial bonding is moved into a baking box or a UV box for heat curing or UV curing. After the adhesive is cured and cooled, the transfer process is completed.

9. The transfer method according to claim 8, characterized in that: In step S2, the glue is laminated onto the surface of the substrate by rolling with a pressure roller or pressing with a flexible elastic body.

10. The transfer method according to claim 8, characterized in that: The release layer and the flexible substrate layer are recovered by the substrate winding drum, and the transfer film is recovered by the transfer film winding drum.

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