KR102476337B1 - Image film having multiple layer and transfer material - Google Patents

Abstract

An image film including a base film, an image layer positioned on one side of the base film, and a lens layer positioned on the other side of the base film, and further comprising a buffer layer between the image layer and the lens layer, and the image film Provide transfer materials.

Description

Three-dimensional image film and transfer material having multi-layer structure {IMAGE FILM HAVING MULTIPLE LAYER AND TRANSFER MATERIAL}

The present invention relates to an image film for security and a transfer material including the image film.

With the recent development of mobile devices, counterfeit products are on the rise. Because it is so elaborately manufactured that it is difficult even for experts to distinguish, consumers who purchase it knowing that it is genuine have reached a considerable level of damage. The problem is that it is difficult to distinguish genuine products from counterfeit products based on appearance. In the meantime, efforts have been made to develop technology at the corporate level to solve this problem, but it is not possible to obtain effective results due to problems such as cost for research and application of security technology or equipment required to check forgery. Accordingly, there is an urgent need to develop a new security technology to cope with increasingly increasing counterfeit products.

In order to solve this problem, various authenticity detection methods are being developed. As one of the methods for determining authenticity, labels that cannot be easily counterfeited and manufactured by others are attached through gold foil embossing or laser engraving. However, with the development of printing technology or gold leaf technology, even the corresponding label can be copied without difficulty, so the purpose is not sufficiently achieved.

Accordingly, new film manufacturing technologies, such as labels through printing processing that causes color change by heat, are being developed. In addition, a technology has been developed in which a specific image is not expressed in a normal state but is displayed only when the film is viewed from a specific angle by constructing a film using a hidden image that appears when a specific state changes. . A method of expressing hidden images is to print on a transparent or translucent substrate in a form that makes it difficult to identify specific information by saturation and brightness, and then illuminate the substrate with light from a monitor (specific state change) to identify hidden information. There is a way to make it possible. That is, the conventional hidden image expression used a method of inducing visual illusion by differentiating the brightness or saturation of the background and image painted with dyes or pigments, or by making the background or image composed of fine and complex patterns or symbols.

In this way, a film produced by printing using conventional dyes or pigments merely expresses a two-dimensional image, and there is also a problem of discoloration due to ultraviolet rays or the like of dyes or pigments.

Accordingly, a three-dimensional lens sheet capable of reconstructing a flat 2D image into a three-dimensional video object by utilizing the principle of optical illusion caused by binocular parallax using a lenticular or microlens is being illuminated. In the conventional three-dimensional image expression method through a three-dimensional lens sheet, a three-dimensional effect and various transformation effects of the image were used by combining a lenticular lens or a microlens on an image expressed with dyes or pigments. In other words, the most important factor to feel the three-dimensional effect is to use the binocular disparity that appears because the human eyes exist at a distance of about 65 mm in the horizontal direction. Using a stereo lens, the blocking effect of some images and the selective advancement of light By using the effect, the effect of a 3D stereoscopic image can be obtained with a 2D flat image.

An embodiment may provide an image film having excellent security, having a thin thickness, and greatly reducing the occurrence 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 side of the base film, and a lens layer positioned on the other side of the base film, and further including a buffer layer between the image layer and the lens layer. .

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

The buffer layer may be positioned 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-based resin, a urethane-based resin, an acrylic resin, an epoxy-based resin, or a combination thereof.

The lens layer may be a diverging lens layer.

A 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 (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 ( PI, Polyimide), polyurethane (PU), or thermoplastic polyurethane (TPU).

The protective film may be hard coated.

Another embodiment provides a transfer material including the image film.

The specific details of other aspects of the present invention are included in the detailed description below.

The image film according to one embodiment further includes a buffer layer, so that the focal length can be easily adjusted without modifying the size of the lens, so that a very clear image can be provided.

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

Preferred embodiments of the present invention will be described in detail. 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 so that the disclosed content will be thorough and complete and the spirit of the present invention will be sufficiently conveyed to those skilled in the art.

Hereinafter, preferred embodiments will be described in detail so that those skilled in the art can easily practice the present invention with reference to the accompanying drawings. However, in describing a preferred embodiment of the present invention in detail, if it is determined that a detailed description of a related known function or configuration 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 actions.

In addition, throughout the specification, when a part is said to be 'connected' to another part, this is not only the case where it is 'directly connected', but also the case where it is 'indirectly connected' with another element in between. include In addition, 'including' a certain component means that other components may be further included, rather than excluding other components unless otherwise stated.

One embodiment relates to an image film expressing a three-dimensional image, wherein the image film includes a base film, an image layer positioned on one side of the base film, and a lens layer positioned on the other side of the base film, and the image layer And a buffer layer is further included between the lens layer.

In general, it is most important to adjust the focal length of an image film to increase image sharpness, and the focal length can be adjusted according to the size of the lens constituting the lens layer. However, since the lens layer constituting the image film is expensive, a lot of cost is incurred whenever the lens layer is changed to adjust the size of the lens. In addition, as time passes, the adhesive strength between the lens layer and the base film inevitably deteriorates, which leads to a deformation of the focal length and causes a decrease in image sharpness. The image film according to one embodiment not only increases image sharpness by easily adjusting the focal length without changing the lens size by using an additional buffer layer, but also improves the adhesion between the lens layer and the base film or between the base film and the image layer, It can also solve the problem of deterioration of image sharpness caused by deterioration of adhesion over time. It is believed that this is because the buffer layer serves as a kind of primer coating layer. On the other hand, since the additional buffer layer according to one embodiment is further included, the film thickness is inevitably increased. As described above, the adjustment of the focal length is very easy due to the buffer layer, so that the Since the thickness can be greatly reduced, it is possible to achieve a thickness equal to or thinner than that of conventional image films.

For example, only one buffer layer may be present in the image film according to an embodiment, or two buffer layers may be present. For example, when the image film includes one buffer layer, the buffer layer may be positioned between the lens layer and the base film, or may be positioned between the base film and the image layer. For example, when the image film includes two buffer layers, 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 where there is one buffer layer, when there are two buffer layers, the adhesive force between the lens layer, the base film and the image layer can be further improved, and the focal length can be more easily adjusted, 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 as each other. However, when the first buffer layer and the second buffer layer are located adjacent to each other, the distance between the lens layer and the base film or between the base film and the image layer becomes too far, which is rather disadvantageous in adjusting the focal length, and the image sharpness is reduced. may or may not be desirable.

The buffer layer may include a polyester-based resin such as polyethylene terephthalate, a urethane-based resin, an acrylic resin, an epoxy-based resin, or a combination thereof. When the buffer layer includes the resin, it is easy to control the refractive index, so image sharpness can be greatly improved by adjusting the focal length, and an excellent effect in improving adhesion can be obtained.

For example, the lens layer may be a diverging lens layer. When the lens layer is a diverging lens layer, when the above-described buffer layer is applied, the focal length can be easily adjusted and image sharpness can be increased.

A 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, it is disadvantageous to adjust the focal length, and image sharpness may be deteriorated.

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 indices of the lens layer and the image layer are within the above range, the focal length may be more easily adjusted when the above-described buffer layer is applied.

Although the above effect can be implemented by additionally applying the buffer layer, the refractive index difference is also very important. By satisfying the refractive index difference, the thickness of the image film according to an embodiment may 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, so there is a limit to utilizing / applying it to the application, and the difference in refractive index between the lens layer and the buffer layer When is greater than 0.25, the thickness of the film becomes thinner, but the efficiency of reducing the focal length decreases, reducing the wide viewing angle (where images can be seen clearly), and the frequency of spherical aberration occurring at the interface of the lens increases, which is undesirable. not.

Conventionally, since there is no image film having the same configuration as the image film according to one embodiment, a clear image is realized but the film is thick, so there are limitations in applying to other applications, or the film is thin but the wide viewing angle is narrow, so the image Due to the problem of not being clearly visible, films for security purposes are generally manufactured using holograms. Thus, it is possible to manufacture films for security purposes.

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

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

The image layer may be a cured layer of a composition including pigments, dyes, or pearls.

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

The image film according to one 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 additionally have higher hardness through a heart coating process.

The protective film and 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 any film capable of printing and imprinting can be used as the protective film and base film. .

Meanwhile, another embodiment of the present invention provides a transfer material including the image film described above.

For example, the transfer material may include the image film, an adhesive layer formed under the image film, and a release film formed over a lens layer or 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 product. Depending on the embodiment, it may be formed using various known heat-sensitive or pressure-sensitive resins, such as polyacrylic resins, polystyrene-based resins, polyamide-based resins, chlorinated polyolefin-based resins, and chlorinated ethylene-vinyl acetate copolymer resins. Alternatively, it may be formed using a rubber-based resin or the like, but is not necessarily limited thereto.

The release film is peeled off after being adhered to the molded article, and may be formed on the top of the image film. Depending on the embodiment, a resin film mainly composed 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 cellulose-based sheet such as glycine paper, coated paper or cellophane, or a composite sheet of two or more of the above as a substrate, and a release treatment is performed on one surface of the substrate to form a release layer, thereby forming a release film. . In this case, the release treatment method for forming the release layer is not particularly limited, and examples thereof include epoxy-based, epoxy-melamine-based, aminoalkyd-based, acrylic-based, melamine-based, silicone-based, fluorine-based, cellulose-based, urea resin-based, polyolefin-based, It can be formed using various printing methods or coating methods using paraffin-based or two or more of the above composite release agents.

The image film according to one embodiment may constitute a transfer material by further including an adhesive layer and a release film, and may be used in a manner of transferring the same to the surface of a desired molded article.

As a method of transferring a transfer material including an image film to a molded product according to an embodiment, the adhesive layer of the transfer material is disposed so as to contact the surface of the molded product, the temperature is about 80 ° C to 260 ° C, and the pressure is 50 kg / m 2 to 200 kg / m 2 Under the condition, when heat and pressure are applied to the release film side with a transfer machine such as a heat-resistant rubber-like elastomer, 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 It can be. However, this is limited to one embodiment, and the image film may be transferred to the molded article 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 woodwork product, a metal product, a composite product of two or more of the above, or any other type of molded product requiring hard coating. Examples of the resin of the resin molded product described above include polystyrene-based resins, polyolefin-based resins, ABS resins, AS resins, and general-purpose resins such as AN resins. In addition, polyphenylene oxide polystyrene-based resins, polycarbonate-based resins, polyacetal-based resins, acrylic resins, polycarbonate-modified polyphenylene ether resins, polyethylene terephthalate resins, polybutylene terephthalate resins, or ultra-high molecular weight polyethylene resins, etc. general-purpose engineering resins, polysulfone resins, polyphenylene sulfide-based resins, polyphenylene oxide-based resins, polyacrylate resins, polyetherimide resins, polyimide resins, liquid crystal polyester resins, and polyaryl-based heat-resistant resins. Engineering resins can also be used. Additionally, in the present invention, composite resins to which reinforcing materials such as glass fibers and inorganic fillers are added can also be used.

The film according to one embodiment may be used in most exteriors of 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 requiring three-dimensional expression such as business cards, credit cards, decorative materials, keypads, packaging materials, switches, sidewalk blocks, coasters, billboards, interior props, wallpaper, photos, cards, etc. can be utilized

The present invention is not limited to the above embodiments, but can be manufactured in a variety of different forms, and those skilled in the art to which the present invention pertains may take other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that it can be implemented as. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

1: lens layer
2: buffer layer
3: base film
4: image layer

Claims (13)

A first buffer layer including a base film, an image layer positioned on one side of the base film, and a diverging lens layer positioned on the other side of the base film, and positioned between the diverging lens layer and the base film, and the base film and image layer Further comprising a second buffer layer located between,
The image layer is a cured layer of a composition containing a pigment, dye or pearl having a refractive index of 1.47 to 1.60,
The first buffer layer and the second buffer layer each independently include a polyester-based resin, a urethane-based resin, an acrylic resin, an epoxy-based resin, or a combination thereof,
The difference in refractive index between the diverging lens layer and the first buffer layer is 0.15 or more,
The difference in refractive index between the diverging lens layer and the second buffer layer is 0.15 or more,
The radius of curvature of the lens of the diverging lens layer is 30 to 50,
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), or Thermoplastic Polyurethane (TPU) image security film.
delete delete delete delete delete In paragraph 1,
The diverging lens layer has a refractive index of 1.47 to 1.67 image security film.
delete delete In paragraph 1,
The image security film further comprises a protective film positioned on one side of the diverging lens layer.
In paragraph 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), or Thermoplastic Polyurethane (TPU) image security film.
In paragraph 10,
The protective film is a hard-coated image security film.
A transfer material comprising the image security film according to any one of claims 1, 7 and 10 to 12.

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