KR20200034085A - Image film having multiple layer and transfer material - Google Patents

Abstract

Provided are: an image film comprising a base film, an image layer positioned on one surface of the base film, and a lens layer positioned on the other surface of the base film, and further comprising a buffer layer between the image layer and the lens layer; and a transfer material comprising the image film. An embodiment can provide the image film which is excellent in security, has a thin thickness, and can significantly reduce the frequency of spherical aberration.

Description

Multi-layered stereoscopic image film and transfer material {IMAGE FILM HAVING MULTIPLE LAYER AND TRANSFER MATERIAL}

The present invention relates to a security image film and a transfer material comprising the image film.

With the recent development of mobile devices, counterfeit products are rapidly increasing. Since it is manufactured to be sophisticated enough to discriminate even experts, the damage of consumers who know and buy as genuine products has reached a considerable level. The problem is that it is difficult to distinguish counterfeit products from genuine products. In the meantime, efforts have been made to develop technologies at the corporate level to solve these problems, but it is not possible to obtain effective results due to problems such as cost for research and application of security technologies and equipment required to check for forgery. Accordingly, it is urgent to develop a new security technology to cope with the increasing number of counterfeit products.

Various authenticity discrimination methods have been developed to solve this problem. As one of the methods for discrimination of authenticity, a label that other people cannot forge and manufacture through gold foil or laser engraving may be attached. However, due to the development of printing technology or gold foil technology, even the corresponding label can be reproduced without difficulty, and thus, the purpose has not been sufficiently achieved.

Accordingly, new types of film manufacturing technologies such as labels through print processing that cause color changes by heat are being developed. In addition, a technology has been developed to configure a film by using a hidden image that is not expressed in a general state but is displayed when a specific state is changed, so that the corresponding trademark or the like is displayed only when the film is viewed from a specific angle. . As a method of expressing hidden images, it is difficult to identify specific information by saturation and lightness, and after printing on a transparent or translucent substrate, the substrate is illuminated by the light of the monitor (change in a specific state) to identify hidden information. There is a way to do it. That is, the conventional hidden image expression used a method of causing visual illusion by changing the brightness or saturation of the background and the image painted with a dye or pigment, or by making the background or image composed of fine and complicated patterns or symbols.

As described above, a film produced by printing using a conventional dye or pigment is merely a representation of a two-dimensional image, and there is also a problem of discoloration of the dye or pigment by ultraviolet rays.

Accordingly, a three-dimensional lens sheet that can reconstruct a planar 2D image into a three-dimensional image using a lenticular or micro lens using an optical illusion principle by binocular parallax is illuminated. In the conventional method for expressing a stereoscopic image through a stereoscopic lens sheet, a lenticular lens or a microlens is combined on an image represented by a dye or pigment to use a stereoscopic effect and various conversion effects of the corresponding image. In other words, the most important factor for feeling the stereoscopic effect is to use a binocular disparity that occurs because the human eye is present about 65 mm apart in the horizontal direction. When a stereoscopic lens is used, the blocking effect of some images and selective light advancement By using the effect, it is possible to obtain the effect of a 3D stereoscopic image as a 2D plane image.

One embodiment can provide an image film that is excellent in security, has a thin thickness, and can significantly reduce the frequency of spherical aberration.

Another embodiment relates to a transfer material including the image film.

One embodiment provides an image film including a base film, an image layer positioned on one surface of the base film, and a lens layer positioned on the other surface of the base film, and further comprising a buffer layer between the image layer and the lens layer .

The buffer layer may be located between the lens layer and the base film.

The buffer layer may be located between the base film and the image layer.

The image film may include a first buffer layer positioned between the lens layer and the base film and a second buffer layer positioned between the base film and the image layer.

The buffer layer may include a polyester resin, a urethane resin, an acrylic resin, an epoxy resin, or a combination thereof.

The lens layer may be a diverging lens layer.

The difference in refractive index between the lens layer and the buffer layer may be 0.15 or more.

The lens layer may have a refractive index of 1.47 to 1.67.

The image layer may have a refractive index of 1.47 to 1.60.

The base film is polyethylene (PE, Polyethylene), polyethylene terephthalate (PET, Polyethylene terephthalate), polyvinyl chloride (PVC, Polyvinyl chloride), polycarbonate (PC, Polycarbonate), polypropylene (PP, Polypropylene), polyimide It may be (PI, Polyimide), polyurethane (PU, Polyurethane) or thermoplastic polyurethane (TPU, Thermoplastic Polyurethane).

The image film may further include a protective film positioned on one surface of the lens layer.

The protective film is polyethylene (PE, Polyethylene), polyethylene terephthalate (PET, Polyethylene terephthalate), polyvinyl chloride (PVC, Polyvinyl chloride), polycarbonate (PC, Polycarbonate), polypropylene (PP, Polypropylene), polyimide ( It may be PI, Polyimide (PU), Polyurethane (PU), or Thermoplastic Polyurethane (TPU).

The protective film may be hard-coated.

Another embodiment provides a transfer material including the image film.

Other details of aspects of the present invention are included in the detailed description below.

The image film according to an embodiment may further include a buffer layer, and a focal length can be easily adjusted without modifying the size of the lens, thereby providing a very clear image.

1 to 3 are diagrams each independently showing an image film configuration according to an embodiment of the present invention.

It will be described in detail preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete and that the spirit of the present invention is sufficiently conveyed to those skilled in the art.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement the present invention. However, in the detailed description of a preferred embodiment of the present invention, when it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the same or similar reference numerals are used throughout the drawings for parts having similar functions and functions.

In addition, in the entire specification, when a part is said to be 'connected' with another part, it is not only 'directly connected', but also 'indirectly connected' with another element in between. Includes. In addition, "including" a component means that other components may be further included instead of excluding other components, unless otherwise stated.

One embodiment is for an image film expressing a stereoscopic image, wherein the image film includes a base film, an image layer positioned on one surface of the base film, and a lens layer positioned on the other surface of the base film, and the image layer And a buffer layer between the lens layer.

In general, it is most important to adjust the focal length of the image film in order to increase image clarity. The focal length can be adjusted to the size of the lenses constituting the lens layer. However, since the lens layer constituting the image film is expensive, a large amount of cost is incurred each time the lens layer is changed to adjust the size of the lens. In addition, as time goes by, the adhesive force between the lens layer and the base film is inevitably lowered, which leads to deformation of the focal length, which causes a decrease in image clarity. The image film according to one embodiment uses an additional buffer layer to easily adjust the focal length without changing the lens size to increase image clarity, as well as improve the adhesion between the lens layer and the base film or the base film and the image layer, The problem of deterioration of image clarity caused by the deterioration of adhesive strength over time can also be solved. This is because the buffer layer acts as a kind of primer coating layer. On the other hand, since it further includes an additional buffer layer according to one embodiment, the film thickness is inevitably increased. As described above, due to the buffer layer, adjustment of a focal length is very easy. Since the thickness can be greatly reduced, it is possible to realize an equivalent level or a thinner thickness than the conventional image film.

For example, only one or two buffer layers may be present in the image film according to an embodiment. For example, when the image film includes one buffer layer, the buffer layer may be located between the lens layer and the base film, or may be located between the base film and the image layer. For example, when two buffer layers of the image film are included, the buffer layer may be divided into a first buffer layer positioned between the lens layer and the base film and a second buffer layer positioned between the base film and the image layer. Compared to the case of one buffer layer, when the two buffer layers, the adhesion between the lens layer, the base film and the image layer can be further improved, and the focal length adjustment is easier, but the overall thickness of the image film may be slightly thicker. The first buffer layer and the second buffer layer may have the same composition and thickness. However, when the first buffer layer and the second buffer layer are positioned adjacent to each other, the distance between the lens layer and the base film or the base film and the image layer becomes too far, which is disadvantageous for adjusting the focal length, and thus the image clarity is deteriorated. May be undesirable.

The buffer layer may include polyester resin such as polyethylene terephthalate, urethane resin, acrylic resin, epoxy resin, or a combination thereof. When the buffer layer includes the resin, it is easy to control the refractive index, and not only can greatly improve image clarity through adjusting a focal length, but also can have an excellent effect in improving adhesion.

For example, the lens layer may be a diverging lens layer. When the lens layer is a divergent lens layer, when the above-described buffer layer is applied, it is easy to adjust a focal length, thereby improving image clarity.

The difference in refractive index between the lens layer and the buffer layer may be 0.15 or more, for example, 0.15 to 0.25. When the difference in refractive index between the lens layer and the buffer layer is less than 0.15, the sharpness of the image may be deteriorated due to disadvantageous adjustment of the focal length.

The lens layer may have a refractive index of 1.47 to 1.67. The image layer may have a refractive index of 1.47 to 1.60. When the refractive indexes of the lens layer and the image layer are within the above range, the focal length adjustment may be easier when the above-described buffer layer is applied.

The above-described effect can be realized by additionally applying the buffer layer, but the difference in refractive index is also very important. By satisfying the difference in refractive index, the thickness of the image film according to one embodiment can be appropriately adjusted. For example, when the difference in refractive index between the lens layer and the buffer layer is less than 0.15, the thickness of the film becomes too thick, for example, it has a thickness of 90 µm or more, and thus there is a limit in utilizing / applying it to the application, and the difference in refractive index between the lens layer and the buffer layer If it is more than 0.25, the thickness of the film becomes thinner, but the efficiency to reduce the focal length decreases, which reduces the wide viewing angle (which allows you to see the image clearly), and the frequency of spherical aberration at the interface of the lens becomes frequent, which is undesirable. not.

In the past, there was no image film having the same configuration as the image film according to one embodiment, so a clear image is realized, but the thickness of the film is limited to apply to other applications, or the thickness of the film is thin but the image viewing angle is narrow due to the narrow viewing angle. Since there is a problem that is not clearly visible, a film for security purposes is generally manufactured using a hologram, but according to one embodiment, since a thin thickness and a wide wide viewing angle can be achieved, various images are used instead of a hologram. Therefore, it is possible to manufacture a film for security purposes.

The lens of the lens layer may have a radius of curvature of 30 to 50, such as 30 to 40, such as 30. When the lens has a high-radius radius in the above range, it is easy to implement the difference in refractive index described above.

The shape of the lens is not limited in shape, and any shape that can be arranged, such as a triangle, a square, a hexagon, or a circle, may be possible. For example, in addition to the basic lens shape, a reticular bar type (one-shaped) lens shape is also possible.

The image layer may be a cured layer of a composition including a pigment, dye, or pearl.

For example, the refractive index of the base film and the image layer may be the same.

The image film according to an embodiment may further include a protective film positioned on one surface of the lens layer. For example, the protective film may be hard coated.

The protective film prevents the lens from being exposed to the outside, thereby greatly reducing the risk of external damage, and may further have a higher hardness through a heart coating process.

The protective film and the base film are each independently polyethylene (PE, Polyethylene), polyethylene terephthalate (PET, Polyethylene terephthalate), polyvinyl chloride (PVC, Polyvinyl chloride), polycarbonate (PC, Polycarbonate), polypropylene (PP, Polypropylene), polyimide (PI, Polyimide), polyurethane (PU, Polyurethane) or thermoplastic polyurethane (TPU, Thermoplastic Polyurethane), but may be a film capable of printing and imprinting may be used as the protective film and the base film. .

On the other hand, another embodiment of the present invention provides a transfer material including the above-described image film.

For example, the transfer material may be configured to include the image film, an adhesive layer formed on the lower portion of the image film, and a release film formed on the lens layer or the protective film of the image film.

The adhesive layer may be formed under the image forming layer or the light shielding layer of the image film, and may serve to fix and attach the image film to the molded article. Depending on the embodiment, it can be formed using various known thermosensitive or pressure-sensitive resins, for example, polyacrylic resin, polystyrene resin, polyamide-based, chlorinated polyolefin-based resin, chlorinated ethylene-vinyl acetate copolymer resin Or it may be formed using a rubber-based resin, but is not limited thereto.

The release film, which is peeled after adhesion to the molded article, may be formed on the top of the image film. Depending on the embodiment, a resin film mainly made of polypropylene-based resin, polyethylene-based resin, polyamide-based resin, polyester-based resin, polyacrylic-based resin or polyvinyl chloride-based resin, and metal foil such as aluminum foil or copper foil A release film may be formed by forming a release layer by performing a release treatment on one surface of the substrate, using a cellulose-based sheet such as glycine paper, coated paper or cellophane, or a composite sheet of two or more of the above. . In this case, the release treatment method for forming the release layer is not particularly limited, for example, epoxy-based, epoxy-melamine-based, amino-alkyd-based, acrylic-based, melamine-based, silicone-based, fluorine-based, cellulose-based, urea resin-based, polyolefin-based, It may be formed using various printing methods or a coating method using a paraffin-based or a composite release agent of two or more of the above.

The image film according to an embodiment may further include an adhesive layer and a release film as described above to constitute a transfer material, and may be used as a method of transferring it to a surface of a desired molded product.

As a transfer method of a transfer material including an image film according to an embodiment to a molded article, the adhesive layer of the transfer material is placed so as to contact the surface of the molded article, the temperature is about 80 ° C to 260 ° C, and the pressure is 50kg / m2 to 200kg / m2 Under conditions, when heat and pressure are applied to the release film side with a transfer device such as a heat-resistant rubber-like elastic body, and then the release film is peeled off after the cooling process, peeling occurs at the interface between the image film and the release film, and the image film is transferred to the surface of the molded product. Can be. However, this is limited to one embodiment, and in addition, the image film may be transferred to a molded product by various methods such as a mold injection method.

The material of the molded article is not particularly limited. For example, the molded product may be a resin molded product, a woodworking product, a metal product, a composite product of two or more of the above, or any other molded product requiring hard coating. As the resin of the resin molded article, general-purpose resins such as polystyrene-based resins, polyolefin-based resins, ABS resins, AS resins, or AN resins may be mentioned. In addition, polyphenylene oxide polystyrene resins, polycarbonate resins, polyacetal resins, acrylic resins, polycarbonate modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, or ultra high molecular weight polyethylene resins, etc. Universal engineering resin, polysulfone resin, polyphenylene sulfide resin, polyphenylene oxide resin, polyacrylate resin, polyetherimide resin, polyimide resin, liquid crystal polyester resin, polyaryl heat resistant resin, super Engineering resins can also be used. In addition, in the present invention, a composite resin to which a reinforcing material such as glass fiber or inorganic filler is added can also be used.

The film according to one embodiment may be used in most fields used in portable electronic devices, such as keypads of mobile phones in various fields. Furthermore, the image film according to one embodiment is useful for various products that require three-dimensional representation such as business cards, credit cards, decorative materials, keypads, packaging materials, switches, sidewalk blocks, coasters, billboards, interior accessories, wallpaper, photos, cards, etc. Can be utilized.

The present invention is not limited to the above embodiments, but may be manufactured in various different forms, and those skilled in the art to which the present invention pertains have other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that can be carried out. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

1: Lens layer
2: Buffer layer
3: base film
4: Image layer

Claims (13)

An image film including a base film, an image layer positioned on one surface of the base film, and a lens layer positioned on the other surface of the base film, and further comprising a buffer layer between the image layer and the lens layer.
In claim 1,
The buffer layer is an image film positioned between the lens layer and the base film.
In claim 1,
The buffer layer is an image film positioned between the base film and the image layer.
In claim 1,
The image film includes a first buffer layer positioned between the lens layer and the base film, and a second buffer layer positioned between the base film and the image layer.
In claim 1,
The lens layer is a support film that is a divergent lens layer.
In claim 1,
The difference in refractive index between the lens layer and the buffer layer is 0.15 or more image film.
In claim 6,
The lens layer is an image film having a refractive index of 1.47 to 1.67.
In claim 1,
The image layer is an image film having a refractive index of 1.47 to 1.60.
In claim 1,
The base film is polyethylene (PE, Polyethylene), polyethylene terephthalate (PET, Polyethylene terephthalate), polyvinyl chloride (PVC, Polyvinyl chloride), polycarbonate (PC, Polycarbonate), polypropylene (PP, Polypropylene), polyimide (PI, Polyimide), polyurethane (PU, Polyurethane) or thermoplastic polyurethane (TPU, Thermoplastic Polyurethane).
In claim 1,
The image film further includes a protective film positioned on one surface of the lens layer.
In claim 10,
The protective film is polyethylene (PE, Polyethylene), polyethylene terephthalate (PET, Polyethylene terephthalate), polyvinyl chloride (PVC, Polyvinyl chloride), polycarbonate (PC, Polycarbonate), polypropylene (PP, Polypropylene), polyimide (PI, Polyimide), polyurethane (PU, Polyurethane) or thermoplastic polyurethane (TPU, Thermoplastic Polyurethane).
In claim 10,
The protective film is a hard-coated image film.
A transfer material comprising the image film according to any one of claims 1 to 12.

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