CN112918145A - Reusable UV transfer film and production method thereof - Google Patents

Abstract

The invention discloses a reusable UV transfer film which sequentially comprises a PET (polyethylene terephthalate) base layer, a UV imaging information layer, an isolation layer, an aluminum layer and a back adhesive layer from top to bottom, wherein the UV imaging information layer is printed by adopting a UV gravure printing method. Meanwhile, the invention also discloses a production method of the reusable UV transfer film, which comprises the following steps: s1, carrying out corona treatment on a PET base layer; s2, coating UV ink on the PET base layer by adopting gravure printing, and irradiating by using ultraviolet light to solidify the UV ink to obtain a UV imaging information layer; s3, spraying an isolation layer on the information surface of the UV imaging information layer; s4, aluminum plating is carried out on the surface of the isolation layer to form an aluminum layer; and S5, coating a back glue layer below the aluminum layer. The concave-convex microstructure on the UV imaging information layer can form a special holographic anti-counterfeiting pattern on the aluminum layer, the aluminum layer is directly adhered to paper, and the UV imaging information layer is reserved on the PET base film so as to achieve the purpose of repeated use.

Description

Reusable UV transfer film and production method thereof

Technical Field

The invention belongs to the field of transfer films, and particularly relates to a reusable UV transfer film and a production method thereof.

Background

UV printing ink, also called shadowless printing ink or ultraviolet curing printing ink, is printing ink with a UV visible light curing modified acrylate structure, and is a forming agent which can be cured only by ultraviolet light irradiation. Since the 60 s in the 20 th century, UV inks have been rapidly developed and widely used in various fields such as medical and health, aviation, electronics, printing, optical instruments, and the like. The UV ink curing principle is that a photoinitiator (or photosensitizer) in a UV curing material generates active free radicals or cations after absorbing ultraviolet light under the irradiation of ultraviolet rays, and the polymerization, crosslinking and grafting chemical reactions of monomers are initiated, so that the adhesive is converted from a liquid state to a solid state within a few seconds. The paint has the advantages of high hardness, corrosion and friction resistance, difficult scratch, strong adhesive force, strong durability, water resistance, chemical corrosion resistance, wear resistance, aging resistance and the like.

The UV transfer film is characterized in that the lines on the nickel plate are instantaneously transferred to the transfer film by utilizing the characteristic of UV glue instantaneous solidification, then the transfer film is adhered to the surface of paper, then the PET film layer of the transfer film is quickly removed by the transfer film, and then a pattern is printed. Chinese patent CN108407484A discloses a UV transfer film and its production process and application, the UV transfer film is laminated by a PET film layer, a shape-separated base film layer, a UV glue layer, a top coat layer and an aluminized layer, and the shape-separated base film layer, the UV glue layer and the top coat layer are respectively composed of raw materials with specific weight percentages, however, the UV glue layer of the transfer film is firmly bonded with the aluminized layer, when the PET film layer is peeled off, the UV glue layer is still bonded with the aluminized layer, which results in that the UV glue layer can not be reused, and when the transfer film is used again, the UV glue layer needs to be prepared again, so that the production cost is increased.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provide a reusable UV transfer film.

In order to achieve the purpose, the invention adopts the technical scheme that:

the utility model provides a UV transfer film that can use repeatedly, from the top down includes PET basic unit, UV formation of image information layer, isolation layer, aluminium lamination and gum layer in proper order, wherein UV formation of image information layer adopts UV gravure. Different concave-convex microstructures are formed on the PET base layer through UV gravure printing, and the concave-convex microstructures are the UV imaging information layers. The isolation layer is used for separating the PET basic unit, the UV formation of image information layer and the aluminium lamination and the gum layer of lower floor, does benefit to follow-up separation from the isolation layer. The aluminum layer is thin, and interference fringes can be formed on the aluminum layer after the aluminum layer is coated on the concave-convex microstructure of the UV imaging information layer, namely pattern information on the UV imaging information layer is transferred to the aluminum layer to form a holographic anti-counterfeiting pattern. The back glue layer is formed by directly adhering the aluminum layer with the target pattern on the paper.

The use method of the UV transfer film comprises the following steps: the concave-convex microstructure of the UV imaging information layer forms a target pattern on the aluminum layer, then the UV transfer film and the paper are subjected to thermal transfer printing together, the back glue layer and the aluminum layer with the target pattern are adhered to the paper at the moment, the isolation layer is broken, and the PET base layer and the UV imaging information layer are separated from the aluminum layer. Therefore, the holographic anti-counterfeiting pattern on the aluminum layer is directly transferred to the paper, the concave-convex microstructure of the UV imaging information layer is still remained on the peeled PET base layer, and the PET base layer can be reused only after the isolation layer, the aluminum layer and the back glue layer are sprayed again, so that the aim of repeated use is fulfilled.

Preferably, the isolation layer is made of nano wax or resin, and the thickness of the isolation layer is 10-50 nm. The nano wax or resin is large in brittleness and easy to break, so that the PET base layer and the UV imaging information layer on the upper layer can be separated from the aluminum layer and the back glue layer on the lower layer after the isolating layer is broken, and the PET base layer and the UV imaging information layer can be recycled and reused. Wherein too thin a spacer layer can result in processing difficulties; and the isolation layer too thick can be difficult to the fracture, leads to PET basic unit, UV formation of image information layer and the aluminium lamination and the gum layer of lower floor to separate incompletely, consequently considers the simplicity and the peeling effect of processing comprehensively, selects the thickness of isolation layer 10 ~ 50 nm.

Preferably, the thickness of the isolation layer is 30 nm.

Preferably, the thickness of the PET base layer is 35-110 μm, and the PET base layer is too thin, so that the PET base layer can be damaged in the repeated use process; too thick a PET base film affects its optical properties, resulting in poor transparency.

Preferably, the PET base layer has a thickness of 60 μm.

Preferably, the PET substrate is corona treated. The principle is that corona discharge is carried out on the surface of the treated plastic by utilizing high frequency and high voltage to generate low-temperature plasma, so that the adhesion capability of the PET surface is improved, and the adhesion of a UV imaging information layer is facilitated.

Preferably, be equipped with the surface modification layer between the PET basic unit with UV formation of image information layer, the surface modification layer is made by hyperbranched polyurethane, and hyperbranched polyurethane all has stronger adhesive force with PET basic unit and UV formation of image information layer to can increase the adhesive force between UV formation of image information layer and the PET basic unit.

Preferably, the back adhesive layer is made of water-based environment-friendly thermal transfer adhesive. The adhesive capacity of the back adhesive layer and the aluminum layer is strong, so that the aluminum layer with the holographic anti-counterfeiting pattern can be directly adhered to paper.

A method of producing a reusable UV transfer film, comprising the steps of:

s1, carrying out corona treatment on a PET base layer;

s2, coating UV ink on the PET base layer by adopting gravure printing, and irradiating by using ultraviolet light to solidify the UV ink to obtain a UV imaging information layer;

s3, spraying an isolation layer on the information surface of the UV imaging information layer;

s4, aluminum plating is carried out on the surface of the isolation layer to form an aluminum layer;

and S5, coating a back glue layer below the aluminum layer.

Compared with the prior art, the invention has the beneficial effects that:

(1) the isolation layer is additionally arranged between the UV imaging information layer and the aluminum layer, so that the aluminum layer and the UV imaging information layer are conveniently separated, and the UV imaging information layer is kept on the PET base film so as to achieve the purpose of repeated use.

(2) By means of UV gravure printing, a UV imaging information layer with various concave-convex microstructures is formed, and the concave-convex microstructures can form mutually interfered stripes on an aluminum layer, so that a special holographic anti-counterfeiting pattern is formed.

(3) The back glue layer is coated under the aluminum layer, so that the aluminum layer with the special holographic anti-counterfeiting pattern can be directly adhered to paper.

(4) Carry out corona treatment to the PET basic unit to increase the surface modification layer between PET basic unit and UV formation of image information layer, thereby increased the adhesive force between PET basic unit and the UV formation of image information layer, avoided the droing of UV formation of image information layer.

Drawings

FIG. 1 is a schematic structural view of example 1 of the present invention;

FIG. 2 is a schematic structural diagram of example 2 of the present invention;

in the figure: 1. a PET base layer; 2. a UV imaging information layer; 3. an isolation layer; 4. an aluminum layer; 5. a back glue layer; 6. a surface modification layer.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

This example provides a reusable UV transfer film as shown in fig. 1. Firstly, processing PET into 110 mu m to obtain a PET base layer 1, and carrying out corona treatment on the PET base layer 1. And then, feeding the PET base layer 1 with UV ink in a gravure printing mode, irradiating with ultraviolet light to solidify the UV ink, and forming different concave-convex microstructures on the PET base layer 1 to obtain the UV imaging information layer 2. The resin was dissolved in acetone and then sprayed onto the UV imaging information layer 2, resulting in a 50nm thick spacer layer 3. And aluminizing the surface of the isolation layer 3 to form an aluminum layer 4, and finally coating a back glue layer 5 of the water-based environment-friendly thermal transfer glue below the aluminum layer 4 to obtain the reusable UV transfer film.

Due to the thinness of the aluminum layer, the uneven microstructure of the UV imaging information layer 2 forms mutually interfering fringes on the aluminum layer 4, thereby forming a special holographic security pattern on the aluminum layer 4. Then the UV transfer film and the paper are subjected to thermal transfer printing together, at the moment, the back glue layer 5 and the aluminum layer 4 with the holographic anti-counterfeiting pattern are adhered to the paper together, the isolation layer 3 is broken, and the UV imaging information layer 2 is separated from the aluminum layer 4. Therefore, the holographic anti-counterfeiting pattern on the aluminum layer 4 is directly transferred to paper, the concave-convex microstructure of the UV imaging information layer 2 is still reserved on the peeled PET base layer 1, and the UV transfer film can be reused only after the isolation layer 3, the aluminum layer 4 and the back glue layer 5 are sprayed on the surface of the UV imaging information layer 2 again, so that the aim of reusing the UV transfer film is fulfilled.

In the thermal transfer process of the UV transfer film obtained in the embodiment, the isolating layer 3 can be smoothly broken, so that the aluminum layer 4 and the UV imaging information layer 2 are separated, and part of the UV imaging information layer 2 can fall off from the PET base layer 1.

Example 2

The present embodiment is different from embodiment 1 in that: as shown in fig. 2, (1) PET was processed to 60 μm to obtain a PET base layer 1; (2) spraying hyperbranched polyurethane on the lower surface of the PET base layer 1 to serve as a surface modification layer 6, coating UV (ultraviolet) ink on the surface modification layer 6 in a gravure printing mode, irradiating by ultraviolet light to cure the UV ink to obtain a UV imaging information layer 2, wherein the hyperbranched polyurethane has strong adhesive force with the PET base layer 1 and the UV imaging information layer 2, so that the adhesive force between the UV imaging information layer 2 and the PET base layer 1 is enhanced; (3) the nano wax is dissolved by toluene and then sprayed to the UV imaging information layer 2, and the isolation layer 3 with the thickness of 30nm is obtained.

In the thermal transfer process of the UV transfer film obtained in this embodiment, the isolation layer 3 can be smoothly broken to separate the aluminum layer 4 from the UV imaging information layer 2, and compared to embodiment 1, the UV imaging information layer 2 in this embodiment adheres closely to the PET base layer 1 and does not fall off.

Comparative example 1

This comparative example differs from example 2 in that: magnesium oxide is plated on the lower surface of the UV imaging information layer 2 in a PVD (physical vapor deposition) coating mode to obtain an isolation layer 3 with the thickness of 30 nm.

According to the comparative example, the isolating layer 3 can not be broken in the thermal transfer process of the UV transfer film, so that the aluminum layer 4 and the UV imaging information layer 2 can not be separated smoothly.

Comparative example 2

This comparative example differs from example 2 in that: the thickness of the spacer layer 3 was 70 nm.

This comparative example resulted in a UV transfer film that did not completely break during thermal transfer due to the thicker spacer layer 3, resulting in incomplete separation of the aluminum layer 4 and the UV imaging information layer 2.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (9)

1. The reusable UV transfer film is characterized by sequentially comprising a PET (polyethylene terephthalate) base layer, a UV imaging information layer, an isolation layer, an aluminum layer and a back adhesive layer from top to bottom, wherein the UV imaging information layer is printed by adopting a UV gravure printing method.

2. The reusable UV transfer film according to claim 1, wherein the isolation layer is made of nano wax or resin, and the thickness of the isolation layer is 10 to 50 nm.

3. The reusable UV transfer film of claim 2, wherein the spacer layer has a thickness of 30 nm.

4. The reusable UV transfer film according to claim 1, wherein the PET substrate has a thickness of 35 to 110 μm.

5. The reusable UV transfer film according to claim 4, wherein the PET base layer has a thickness of 60 μm.

6. The reusable UV transfer film of claim 1, wherein the PET substrate is corona treated.

7. The reusable UV transfer film according to claim 1, wherein a surface modification layer is provided between the PET base layer and the UV imaging information layer, the surface modification layer being made of hyperbranched polyurethane.

8. The reusable UV transfer film of claim 1, wherein the backing layer is made of an aqueous environmentally friendly thermal transfer adhesive.

9. A method for producing a reusable UV transfer film according to any one of claims 1 to 8, comprising the steps of:

s1, carrying out corona treatment on a PET base layer;

s2, coating UV ink on the PET base layer by adopting gravure printing, and irradiating by using ultraviolet light to solidify the UV ink to obtain a UV imaging information layer;

s3, spraying an isolation layer on the information surface of the UV imaging information layer;

s4, aluminum plating is carried out on the surface of the isolation layer to form an aluminum layer;

and S5, coating a back glue layer below the aluminum layer.

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