JPS63287987A - Hologram - Google Patents

Abstract

PURPOSE:To enable sticking of a holographic image to various objects with a simple operation by providing a volume phase type hologram film of a desired image strippably onto a transparent base material consisting of a crystalline resin. CONSTITUTION:The film-shaped volume phase type hologram film 2 recorded with the desired image is strippably formed on the base material 1 consisting of the transparent and crystalline resin, for example, crystalline high polymers such as PE and PP. The film formed by using a vinyl carbazole polymer as a sensitizing agent and subjecting the same to exposure and development is more adequate in this case. This base material 1 and film 2 are stripped and are stuck to the various objects or the hologram film 2 is transferred to articles, by which the holographic image is easily applied to a desired part.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a volume phase hologram that allows a three-dimensional image to be observed on, for example, a flat film. The present invention relates to a transfer hologram that can be easily provided.

[Conventional technology]

Holography is a method in which an object is irradiated with light waves with good coherence, such as a laser, and the reflected or transmitted light, whose width and phase are modulated according to the shape of the object, is received by a sensitive material and recorded. This is a technique for reproducing an optical image of an object recorded using light irradiated onto a formed hologram. For example, a stereoscopic optical image can be observed on a flat film.

With the progress of research on holography, the requirements for sensitizers have become quite clear. As a sensitizer that can be used in holography, bleaching agent 1'! Many materials are known, such as silver salt 5 photoresists, thermoplastics, dichromate gelatin, electrical glass materials, and strong electric materials, and their suitability for holography is being further studied.

Characteristics that a sensitizer for forming holograms should have include, for example, (1) laser sensitivity, especially laser sensitivity in the visible light region, and high sensitivity; (2) high resolution; (3) The obtained hologram has high diffraction efficiency, (4) hologram noise is low, (5) hologram is stable, and (6) recording and reproducing operations are easy. can.

On the other hand, with the advancement of holography technology, it is becoming possible to form holograms that can withstand practical use, and the uses of holograms are expanding into various fields, such as enjoying the single image itself and using it to decorate various items. holograms are becoming increasingly popular, and holograms are being required to take on various forms in response to these trends.

For example, a type of hologram that reproduces an image by forming unevenness corresponding to the image on the surface of the sensitive layer and utilizing the reflection or transmission of light on the unevenness can be used as a wooden cover, or for counterfeiting or alteration of magnetic cards. It is already used as a preventive mark.

[Problems to be Solved by the Invention] However, in response to the various demands associated with the expansion of the above-mentioned uses, both in terms of the characteristics of the hologram-forming sensitizer mentioned above and the form of the hologram itself, At present, there are no holograms available that can adequately handle this problem.

For example, a technique for applying holograms to various desired objects with simple operations and a form of hologram suitable for this have not yet been provided.

The present invention has been made in view of the various demands that have arisen with the expansion of the uses of holograms, and provides technology that facilitates the application of hologram films to various objects;
The object of the present invention is to provide a hologram film that is particularly excellent in stability, strength, solvent resistance, and the like.

[Means for solving problems]

The above object can be achieved by the following invention. That is, the hologram is characterized by having a transparent base material made of a crystalline resin, and a volume phase type hologram film provided on the base material on which a desired image is written.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic side view showing the configuration of an example of a hologram of the present invention in a sheet shape.

This hologram includes a base material 1 and a hologram film 2 provided on the upper surface of the base material l. Such a hologram film can be used by attaching the back side of the base material to another object, or depending on the adhesive strength between the base material and the hologram film, the two can be peeled off at the same time or after the peeling.
It can be used for transfer to other objects.

That is, a holographic image can be easily applied to a desired portion of various objects made of paper, metal, plastic, ceramic, etc., for example.

For example, as an article to be transferred or pasted, a hologram film can be transferred and pasted onto a suitable mount and enjoyed in the same way as a picture or photograph.

In addition, with the above-mentioned type using an uneven surface, when the hologram is directly adhered to various transfer materials by pressure bonding or adhesion, the unevenness formed on the surface is unavoidably affected by deformation or damage. Since the transfer type hologram uses a volume phase type hologram film, such a gap does not occur during transfer.

Preferred embodiments for both application and transfer will be described later, but first, a hologram film, which is a base material common to both applications, will be explained.

The base material 1 must be transparent and crystalline, and this point constitutes a characteristic part of the present invention.

Transparency refers to having optical properties that do not affect image exposure operations, that is, transparency to the extent that exposure operations can be performed satisfactorily at the wavelength or wavelength range of light used for exposure. Since the base material has such characteristics, a hologram can be formed by exposing and developing five images with the recording material for hologram formation laminated on the base material 1, which is good for production efficiency. Moreover, since the substrate 1 according to the invention is crystalline, it exhibits high stability towards the developer during the development process. From this point of view, the hologram is particularly suitable for practical use. Furthermore, since the base material is a crystal, there is an advantage that the range of usable developers is expanded.

Furthermore, since the base material 1 is crystalline, the hologram of the present invention has the advantage of exhibiting high stability against various solvents during use.

The preferred range of transparency is ASTM 0100
When the light transmittance is measured according to the method described in No. 3, it has a transmittance of 30% or more at 400 nm, preferably 50% or more, and a transmittance of 40% or more at 450 to 800 na. It is.

The strength of the base material 1 may be such that it can support the hologram film 2.

The shape of the base material 1 is not necessarily limited to the sheet shape shown in the figure, but may have various three-dimensional shapes such as a rectangular parallelepiped or a cube.

In addition, it is desirable that the base material 1 when used in the form of a sheet has appropriate flexibility from the viewpoint of being usable for objects having curved surfaces such as cylinders.

Examples of such transparent and crystalline base materials include polyesters such as polyethylene, polypropylene, poly(4-methyl)pentene, polyetheretherketone, polyvinylidene fluoride, polyacrylonitrile, and polyethylene terephthalate; polyesters such as polyamide; The main component is a crystalline polymer, which is made transparent by biaxially stretching during molding to cause oriented crystallization.

When used in the form of a sheet, the thickness of the base material 1 is preferably about 20 μm to 100 μm, for example, from the viewpoint of mechanical strength and transparency.

Further, the base material 1 is observed together with the hologram film 2, that is, the base material 1 is observed together with the hologram film 2 at the time of observation.
If the hologram film 2 is in close contact with
To make the image on the hologram film 2 clearer, for example, by using a color that is complementary to the image recorded on the hologram film 2, within a range that does not interfere with the exposure for forming the hologram film 2.
It may be colored in a color that is effective for improving appearance.

In addition, the surface of the base material 1 on the hologram film 2 side may be subjected to discharge treatment using corona, plasma, etc., flame treatment, etc. for the purpose of improving adhesion with the hologram film 2, if necessary. Physical treatment: Chemical treatment using sulfuric acid, nitric acid, fluorocarbon compounds, alkalis, silane compounds, etc.
A surface treatment such as A-embedding may be applied.

However, it is desirable that the coloring, surface treatment, etc. be carried out within a range that does not impair the above-mentioned optical properties of the base material 1.

As the hologram film 2, various volume phase type holograms in the form of a film on which a desired image is recorded can be used.

Among these, volume-phase holograms using vinylcarbazole polymers as a sensitizer satisfy the performance requirements listed above for sensitizers, and the resulting hologram itself has excellent moisture resistance and storage stability. It also has excellent stability against various operations during hologram coloring or transfer, and is therefore suitable for use in the hologram of the present invention.

The vinylcarbazole polymer refers to polyvinylcarbazole, alkyl-substituted polyvinylcarbazole, halogen-substituted derivatives of polyvinylcarbazole, and polymers mainly composed of these.
More than one species may be used.

Specifically, for example, polyvinylcarbazole, 3-chlorovinylcarbazole polymer, 3-bromvinylcarbazole polymer, 3-iodovinylcarbazole polymer, 3-methylvinylcarbazole polymer, 3-ethylvinylcarbazole polymer, Chlorinated polyvinyl carbazole, brominated polyvinyl carbazole, etc. can be used.

Among them, unsubstituted polyvinyl rubazole is practically suitable because it is easily available and the performance of the obtained hologram is particularly excellent.

The vinyl carbazole polymer may be copolymerized with other polymers, if necessary, in order to control properties such as strength and flexibility when formed into a film. Other polymers that can be used for such purposes include, for example, in addition to the above-mentioned vinyl carbazoles, vinyl esters such as vinyl acetate, esters of acrylic acid and methacrylic acid, styrene and styrene derivatives, etc. can be produced by radical polymerization. Examples include copolymerizable vinyl yarn threads and the like. Further, other polymers such as polystyrene, styrene-butadiene copolymer, styrene-hydrogenated butadiene copolymer, etc. can also be blended to the extent that a hologram image can be recorded.

Incidentally, the addition ratio of these materials is selected so as to obtain the desired characteristics.

This vinyl carbazole polymer is used for holography in a state activated by radiation with an iodinated metal.

Examples of this iodine compound include carbon tetraiodide, iodoform, ethylene tetraiodide, triiodoethane, tetraiodoethane, pentayodoethane, and hexaiodoethane, which coexist in polymer components and have sufficient resistance to visible light wavelengths. A material capable of forming a sensitive sensitizer is used.

A sensitive layer using a vinylcarbazole polymer with such a configuration exhibits sensitivity to visible light up to 560 nm, and can achieve interference between two beams of object light and reference light with appropriate wavelengths within such a wavelength range. A volume phase type hologram with high resolution and high diffraction efficiency can be formed by exposing an interference pattern to an optical laser and then performing a development process using swelling and shrinkage phenomena caused by a solvent.

Note that the hologram film used in the present invention is not limited to its material or image recording method, and may be made of any material or formed by any recording method; The configuration of the present invention is particularly effective when using a forming method that requires a development step.

In order to provide the hologram film 2 on the base material 1, as described above, a method of laminating a sensitive layer for forming a hologram on a crystalline transparent film and subjecting it to predetermined exposure and development treatments can be suitably used. However, a method may also be used in which a hologram film on which a desired image has already been recorded is used as the hologram film 2, and the film is laminated on the transparent crystal base material 1. In this case as well, the produced product exhibits high solvent resistance and has the advantage of improved mechanical strength.

To use the present invention for transfer, the peelable base material and the exposed surface of the hologram film 2 are superimposed on the surface of the transfer material to which the material is to be transferred.
By pressing these together, the hologram film 2
is transferred onto another desired article.

That is, the term "peelable" as used in the present invention means that the hologram film 2 can be peeled off from the base material 1 without any change in its shape or image recording state during the above-described transfer operation. .

Therefore, the base material 1 and the hologram film 2 are as follows:
It is preferable to select each material in a combination that allows a good transfer operation.

However, in the configuration shown in FIG. 1, if the hologram film 2 is difficult to peel off from the base material 1, or if the hologram film 2 is thin and has low strength, the hologram film 2 and the base material 1 may not be able to be transferred properly. When using a combination of films, a good transfer operation can be achieved by providing a release layer 3 between the base material 1 and the hologram film 2, as shown in FIG. 2, for example.

The release layer 3 used for this purpose is used during the transfer operation.
It is sufficient to use a material having a function of facilitating peeling between the base material 1 and the hologram film 2 and a thickness of F3.

The type of peeling layer 3 may be one that remains on the base material 1 side after the transfer operation, or one that closely adheres to the hologram film z side and is transferred together with it.

The peeling layer 3 used for this purpose has, for example, a surface tension of the hologram film 2 (30 to 35 dyne/cI when N-vinylcarbazole polymer is used).
I), for example, a layer made of a polymer or a low-molecular surface modification called a silane coupling agent or a titanium coupling agent, which has a surface tension sufficiently large or small to obtain a good peeling state. A layer consisting of a quality agent can be used.

Specific examples of materials that can constitute the release layer 3 include polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyfluorinated ethylene-propylene, and polyorganosiloxane; and silane coupling such as γ-glycidoxyprodoltrimethoxysilane and vinyltrimethoxysilane. Agents: titanium coupling agents such as isopro and stearoyl titanate, isopropyloctyl titanate, and the like.

However, when the release layer 3 is transferred together with the hologram film 2 and is left on the hologram film 2 after the transfer operation, the release layer 3 is It must be such that it does not interfere with

In addition, when using a release layer of the type that is left on the hologram film 2, the release layer may be made of a material that functions as a protective layer for the hologram film, or each M additive material that can impart a protective function to the release layer may be used. By adding it to give the peeling layer 3 the function of a protective layer, the protective layer can be automatically provided on the hologram film after transfer.

Materials for forming a release layer that can also function as a protective layer include:
Examples include polyethylene terephthalate, polyether ether ketone, boliber fluoroethylene-brobylene, polyvinylidene fluoride, polyvinyl alcohol, and the like.

Further, as additives that can be added to provide a function as a protective layer, for example, as an ultraviolet absorber, 2-
Examples include triazole derivatives such as (hydroxyphenyl)benzotriazole, triazine derivatives such as 1,3,5-tris(2'hydroxyphenyl)triazine, and benzophenone derivatives such as resorcyl monobenzoate.

The release layer 3 can be provided by laminating, for example, a layer made of the above polymer on the base material 1, or by treating the surface of the base material 1 with a solution containing a silane coupling agent or a titanium coupling agent.

On the other hand, on the exposed surface of the hologram film 2, in order to improve the transfer operation or to improve the fixation of the hologram film on other objects after transfer, as shown in FIG. An adhesive or adhesive layer 4 may also be provided.

The material that can be used for the layer 4 is one that has a good adhesion or adhesive effect, does not give a bad a2ff to the hologram film 2 in the adhesion or adhesion process using the layer, and is itself compatible with the hologram film 2. scientific,
Depending on the configuration of the desired transfer hologram, any material that does not physically react and cause harm may be selected and used.

For example, select and use an acrylic ester polymer, vinyl acetate polymer, α-cyanoacrylate ester, urethane adhesive, rubber adhesive, epoxy adhesive, etc. that satisfies the above characteristics. For example, when using polyester, the copolymer composition of acrylic ester, butyl acrylate, 2-ethylhexyl acrylate, and ethylene can be changed as appropriate to adjust its properties to the target object to obtain the desired effect. Since it is adjusted accordingly, it can be used selectively.

Note that the layer 4 may be pretreated with a primer, if necessary.

In addition, the form of the adhesive or pressure-sensitive adhesive may be one-component type, two-component type, water-based latex, oil-based latex, hot melt type (powder form, sheet form), heat Any form such as a seal type may be used.

Layer 4 can be formed by coating it directly on the hologram film 2 (or sensitive layer for hologram formation), or by gluing it onto the hologram film 2 after it has been formed into a film by casting or the like. Alternatively, an appropriate method of adhesion may be selected and used.

Note that when layer 4 is provided as an adhesive layer, for example, 10
An adhesive layer that can be bonded under conditions of 0 to 120° C. and several kg/cm 2 can be suitably used.

In addition, the adhesion and adhesive strength of layer 4 is, for example, 200 g.
/25 mm or more is sufficient.

A preferred embodiment of the present invention for use in pasting applications is one in which an adhesive or adhesive layer 5 is provided on the back surface of the base material, as shown in FIG. The layer 5 may be appropriately selected depending on the base material.

Furthermore, in the present invention, a protective layer 6 may be provided on the upper surface of the hologram film 2 as shown in FIG.

When the hologram of the present invention is used for pasting, the image of the hologram film is observed through the protective layer 6, so it is desirable that the protective layer 6 not interfere with good observation of the image.

Such a protective layer 6 may be made of polyvinyl alcohol, polyfluorinated ethylene-propylene, polyvinylidene fluoride, etc., when controlling oxygen permeation through the protective layer to prevent the possibility of deterioration of the hologram film due to oxidation. It can be provided as a layer. In addition, the protective layer for preventing scratches due to friction etc. can be formed by forming, for example, a single layer of polysiloxane ladder type polymer, an epoxy resin layer directly on the hologram film 2, or various resin films that have been subjected to these treatments. can be formed by laminating them on the hologram film 2.

Furthermore, when forming the protective layer 6, various protective functions may be formed, such as adding various ultraviolet absorbers that may be added to the above-mentioned peeling layer 3 to impart a photodegradation prevention function. The protective layer 5 may be provided with various desired protective functions by adding various additives that can be added to the layer.

When the protective layer 6 is formed from such a material, the n thickness may be set to the extent necessary for the protective layer to exhibit a sufficient function.

Furthermore, in addition to the above materials, Ink, ^1203. 5 Metals and metal oxides such as AI and 〇 are placed on the hologram film 2.
It may also be used as a protective layer by vapor deposition to a film thickness of about 0 to 1000 layers.

In addition, when using the flexible base material 1, if the height of the protective layer is too high, cracks or damage may occur in the protective layer when it is flexible, and sufficient effects may not be obtained. Therefore, if there is such a risk, it is preferable to set the hardness of the protective layer to, for example, 4H or less in terms of pencil hardness, although this varies depending on the materials of the base material 1 and the hologram film 2.

In addition, when layers 3 to 6 are laminated on the base material 1 or the sensitive layer for hologram formation during exposure for forming a hologram, the same exposure operation as for the transparent base material described above is applied to these layers. optical properties are required.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Poly(N-vinylcarbazole) 2.5% was applied in the dark onto biaxially stretched crystalline polyetheretherketone (Nisbeck, manufactured by Takuhō Kagaku) with a thickness of 50 scales as a base material.
g, 0.2 g of carbon tetraiodide to 30 g of monochlorobenzene
The solution dissolved in
) and dried to obtain a sensitive layer for forming a hologram with a layer thickness of 5.0 μm.

The absorbance of the obtained sensitive layer was measured using a spectrophotometer tlVI [1Ec
-850 (JASCO Group), 560nm
It had an absorption edge of up to

Using a laser beam (<514.5 nm) on this sensitive layer, a desired object is detected according to Denisyuk's method under the conditions of a light intensity ratio of 1:1 (the sum of the light intensities of both beams is 15 mJ/cm2 immediately before the incidence). The corresponding image was recorded.

After exposure, the sensitive layer is sequentially processed through the following steps 1 to 2 to record a desired image on the substrate.The Lippmann type reflection hologram is transferably provided on the substrate. A transfer hologram was obtained.

Immersed in acetone for 2 minutes at 020°C ■ Immersed in xylene for 3 minutes at 30°C ■ Immersed in n-hebutane for 3 minutes at 25°C, then dried The resulting hologram was exposed to light with a wavelength of 514.5 n-. Approximately 3 pieces
It was a volume phase type with a spatial frequency of 000 wood/1l111, a diffraction efficiency of 88%, and a transmittance of 90%.

The transfer type hologram thus obtained was superimposed on a transfer material coated with Polysol 8B-4]2ON (manufactured by Showa Kobunshi Co., Ltd.) on a vinyl chloride sheet via the hologram film surface, and the transfer rate was 2 kg/cs2. By applying a certain amount of pressure with a roller, the hologram film was able to be transferred onto the vinyl chloride sheet in good condition, even though the hologram film was as thin as 5 mm.

The characteristics of the transferred hologram were the same as those immediately after its formation, and a good holographic image could be observed there.

Furthermore, since the polyetheretherketone used in this example is a crystalline polymer, it exhibited excellent solvent resistance even in the development process.

Example 2 A peeling layer was formed on the surface of the film by immersing a crystalline polyethylene terephthalate film, which was double-stretched for 50 μs, in a 10% nitric acid solution for about 30 minutes as a base material.

A transfer hologram of the present invention was obtained by performing exposure and development in the same manner as in Example 1 except that the above film was used as the base material.

When the obtained transfer hologram was transferred onto a vinyl chloride sheet in the same manner as in Example 1, a good peeling effect was obtained by the release layer, and the hologram sheet could be easily transferred onto the vinyl chloride sheet.

The characteristics of the transferred hologram were the same as those immediately after its formation, and although the release layer remained laminated on the top surface of the hologram film, a good holographic image could be observed.

Moreover, the release layer sufficiently functioned as a protective layer for the transferred hologram film.

Comparative Example 1 Using a 0.2-thick polystyrene film as a base material, 2.5 g of poly(N-vinylcarbazole) and 0.2 g of tetraiodide carbon J were added to 30 g of monochlorobenzene in a dark place on the film. When the dissolved solution was applied using a spinner (Mikasas Viner, II+-2), the film was dissolved and a holographic sensitive layer could not be obtained.

Comparative Example 2 Exposure and development were carried out in the same manner as in Example 1 except that a non-quality polymeric polyether sulfone film (Nispex-5, ffE Tomo (1tJ)) was used as the base material. The photosensitive layer swelled and dissolved, and the sensitive layer peeled off, making it impossible to perform good development.

Example 3 Vinyl roll E^ was placed on the back side of the hologram substrate obtained in Example 1.
-300 (manufactured by Showa Kobunshi Co., Ltd.) was coated to a dry film thickness of 5 μm to form an adhesive hologram.

The adhesive hologram obtained in this way was superimposed on a stainless steel plate via the adhesive layer, and was heated to 2 kg/cm at 50°C.
By applying a pressure of 2, the hologram film could be fixed on the stainless steel plate.

The properties of the fixed hologram were the same as those immediately after its formation, and a good holographic image could be observed there.

〔Effect of the invention〕

The hologram of the present invention has a structure in which a hologram film is provided on a suitable base material, and an adhesive or pasting layer is provided on at least one surface of the base material, and the hologram can be pasted onto the base material using this layer. A desired holographic image can be easily and easily applied to a desired part of various articles by a simple operation of transferring the hologram film held thereon to a desired article. Furthermore, for example, the hologram can be glued or pasted together with the base material onto a suitable mount, or the hologram film can be transferred and enjoyed in the same way as a picture or photograph. Moreover, since the substrate is transparent and crystalline, as mentioned above, manufacturing efficiency is improved and f! J.J.
It can facilitate manufacturing operations, improve solvent resistance during manufacturing and during product use, improve product strength, and be applied to large m manufacturing processes. Further, according to the present invention, the range of developing solutions that can be used after the exposure step for forming a hologram can be expanded.

Furthermore, in the type that uses the uneven surface described above, when holograms are directly laminated on various members by pressure bonding or adhesion, the unevenness formed on the surface is unavoidably affected by deformation or damage. Adhesive or sticky holograms include
Since a volume phase type hologram film is used, such noise does not occur during transfer.

[Brief explanation of the drawing]

1 to 5 are schematic side views showing typical configuration examples of the hologram of the present invention, respectively. Base material 2: Hologram film 3: Release layer 4.5: Adhesive or adhesive layer 6: Protective layer

Claims (1)

[Scope of Claims] 1) A hologram comprising a transparent base material made of a crystalline resin and a volume phase type hologram film provided on the base material and recorded with a desired image. 2) The hologram according to claim 1, wherein the volume phase type hologram film is provided so as to be peelable from the base material. 3) The hologram according to claim 1, wherein an adhesive or adhesive layer is provided on at least one surface of the base material.