JP2582778B2 - Method of manufacturing volume phase hologram - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a volume phase hologram capable of observing a three-dimensional image on, for example, a flat film, and more particularly, to transferring or attaching a holographic image to wood, paper, or plastic. The present invention relates to a method of manufacturing a hologram that can be provided easily and easily on ceramics or the like.

[Conventional technology]

Holography irradiates an object with a wave of light with good coherence like a laser, and receives and records the reflected or transmitted light whose amplitude and phase are modulated according to the shape of the object with a photosensitive agent, It is a technique to reproduce the optical image of the object recorded by the light irradiated on the formed hologram, for example,
A stereoscopic optical image can be observed on a flat film.

With the progress of such holographic research, the demand for the photosensitizer has become quite clear. As photosensitive agents that can be used for holography, many materials such as silver salts subjected to bleaching treatment, photoresists, thermoplastics, gelatin dichromate, acid-free glass materials, and ferroelectrics are known, and their suitability for holography is known. Further study.

The characteristics that the photosensitive agent for hologram formation should have are:
For example, (1) having laser sensitivity, particularly having a laser sensitivity in the visible light region, and having high sensitivity; (2) having high resolution; (3) having a high diffraction efficiency of the obtained hologram; ) The hologram has little noise, (5) the hologram is stable, and (6) the recording and reproducing operations are easy.

By the way, with the progress of holography technology, it is becoming possible to form holograms that can withstand practical use.
The use of holograms has been expanded in various directions, such as for enjoying images themselves and for decorating various articles, and various forms corresponding to them have been demanded for holograms.

For example, forming irregularities according to the image on the photosensitive agent layer surface,
A hologram of a type that reproduces an image by using the reflection or transmission of light on the unevenness has already been used as a cover of a book or as a mark for preventing forgery or alteration of a magnetic card.

[Problems to be solved by the invention]

On the other hand, since the volume phase hologram has characteristics of high resolution and high diffraction efficiency, it is required to give a more luxurious feeling and expand its use. However, dichromated gelatin, for example, has been pointed out as a major drawback in terms of storage stability and low moisture resistance of the obtained hologram. A volume phase holograph using a vinyl carbazole polymer as a photosensitizer
It is to overcome the above problems.

However, in a volume phase hologram, a mere combination of the conventional techniques cannot expand the application unlike a surface reflection hologram, so that the hologram is merely fixedly laminated on a transparent substrate.

Therefore, the present inventors have developed a method for producing a sheet-like hologram which can be used for producing a new transfer type hologram and which is useful for expanding a wide range of applications, particularly for producing a hologram sheet having a unique shape other than a flat plate. The present invention has been completed as a result of intensive studies on the development of a manufacturing method that can be suitably used, and a method of manufacturing a transfer and an attachment hologram using this sheet.

That is, an object of the present invention is to provide a method for easily manufacturing a hologram sheet (film) and a method for manufacturing a hologram that can be used for transfer, attachment and the like using the sheet.

[Means for solving the problem]

The above object can be achieved by the present invention described below.

That is, a photosensitive material layer containing a vinylcarbazole-based polymer as a main component is laminated on a transparent substrate made of a polymer, exposed and developed, and then the polymer is dissolved and the vinylcarbazole-based polymer is substantially dissolved. A method of manufacturing a volume phase hologram sheet, characterized by immersing in a solvent that does not dissolve, dissolving and removing a transparent substrate, and swelling and peeling, and a method of manufacturing a volume phase hologram by laminating the sheet on a substrate.

The hologram sheet can be easily manufactured by such a manufacturing method. If this sheet is provided on a substrate so that it can be peeled off, a desired holographic image can be applied to various objects such as paper, metal, plastic, and ceramic by a simple operation of transfer. Further, the hologram sheet provided on the base material can be used for attaching the base material to another object.

In the type using the uneven surface described above, when a holograph is directly adhered onto various types of materials to be transferred by pressure bonding or adhesion, the influence of deformation or breakage on the unevenness formed on the surface cannot be avoided. Since a volume type phase hologram is used in a transfer sheet or the like using a hologram sheet made by the method described above, such a problem does not occur at the time of transfer.

Hereinafter, typical embodiments of the present invention will be described step by step.

First, a photosensitive material layer containing a vinylcarbazole-based polymer as a main component is formed on a transparent substrate (first step). As this transparent substrate, a substrate having no noticeable absorber in the visible light region can be used. In particular, when the light transmittance is measured according to the method described in ASTM D 1003, it is 30% at 400 nm.
Or more, preferably having a transmittance of 50% or more, and 450 to 8
It is preferable to use one having a transmittance of 40% or more at 00 nm.

At this time, as long as the above conditions are not impaired, an ultraviolet absorber and a coloring agent can be mixed into the transparent substrate to prevent light deterioration.

Further, in the present invention, it is necessary to select a substrate material in consideration of a melting step described later. Therefore, preferred substrate materials will be described in the description.

Discharge treatment using corona, plasma, etc. on the surface of the transparent substrate on the side of the photosensitive material layer mainly composed of a vinyl carbazole polymer for the purpose of enhancing the affinity with the photosensitive material layer, etc. Physical treatment such as sulfuric acid, nitric acid, a fluorine compound, an alkali, a silane compound or the like, and a surface treatment such as a scientific treatment. However, it is necessary to perform the operation within a range where the required optical characteristics described above are not impaired.

The thickness of the transparent substrate is set depending on its mechanical strength, light transmittance, and the like, and is preferably 10 μm or more and 10 mm or less.

The photosensitive material layer mainly composed of a vinyl carbazool-based polymer formed on a transparent substrate is used in the present invention because the obtained hologram itself is excellent in overall moisture resistance, storage stability, diffraction efficiency and the like. . The vinyl carbazole polymer refers to polyvinyl carbazole, an alkyl-substituted product of polyvinyl carbazole, a halogen-substituted derivative of polyvinyl carbazole, and a polymer mainly composed of these, and one or more of these may be used as desired. Specifically, for example, polyvinyl carbazole, 3-chlorovinyl carbazole polymer, 3-bromo vinyl carbazole polymer, 3-iodo vinyl carbazole polymer, 3-methyl vinyl carbazole polymer, 3-ethyl vinyl carbazole polymer, Chlorinated polyvinyl carbazole, brominated polyvinyl carbazole, and the like can be used.

Among them, unsubstituted vinyl carbazole polymers
Since it is easy to obtain and the obtained hologram has particularly excellent performance, it is practically suitable.

The vinyl carbazole-based polymer may be copolymerized with another monomer, if necessary, for controlling properties such as strength and flexibility when formed into a film. Other monomers that can be used in such applications include, for example, in addition to the above-mentioned vinyl carbazoles, vinyl esters such as vinyl acetate, acrylic acid, esters of methacrylic acid, styrene and styrene derivatives copolymerized by radical polymerization. And vinyl monomers which can be used. Further, for example, other polymers such as polystyrene, styrene-butadiene copolymer, and styrene-hydrogenated butadiene copolymer can be blended and used as long as a hologram image can be recorded.

These are used by selecting the ratio of addition so that desired characteristics can be obtained.

As the iodine compound, for example, carbon tetraiodide, iodoform, ethylene tetraiodide, triiodoethane, tetraiodoethane, pentaiodoethane, coexist in a polymer component such as hexaiodoethane, sufficient for visible light wavelength Those that can form a photosensitive layer having sensitivity are used.

In addition, to form a photosensitive agent layer containing a vinylcarbazool-based polymer as a main component on a transparent substrate, specifically, dissolving the polymer in a solvent that does not dissolve the substrate, spin-coating the substrate, It may be applied by a known technique such as a bar coat and dried.

Next, by exposing and developing the photosensitive material layer,
A volume phase hologram image is formed (second step).
The exposure method may be any known photosensitive method, and may be appropriately selected depending on the type of the subject, the use of the hologram, and the like.
The developing method may be any of known photosensitizing methods, and may be, for example, a method disclosed in JP-A-54-102140.

More specifically, for example, with an argon laser light of 488 nm, the interference pattern is exposed by a coherent laser of two light fluxes of the object light and the reference light, and then, a swelling due to a solvent, a developing step of developing a contraction phenomenon By going through
Can be implemented.

Thereafter, the film on which the hologram image is recorded is dipped in the transparent substrate in a solvent, and only the transparent substrate is dissolved to obtain a hologram film. (Third step). Therefore, as the solvent that can be used in this step, a solvent that dissolves or swells the vinylcarbazool-based polymer is generally not preferable. Those that do not substantially dissolve and swell the polymer include aliphatic hydrocarbons, carbon tetrachloride, ethylene tetrachloride, mono- and polyhydric alcohols, cellosolves, ethyl ether, dimethyltetrahydrofuran, acetal, aromatic ketones, Aliphatic esters, water and the like. A transparent polymer compound that does not dissolve in these solvents can be used as a substrate material in the first step. Examples include polyacrylates, polymethyl methacrylate, polyvinyl acetate, polystyrene and polyvinyl alcohol,
Natural polymers such as polyvinylpyrrolidone, polyacrylamide, cellulose derivatives, agar, and starch can be used.

However, in the present invention, it is preferred in embodiments that a water-soluble polymer is used as the transparent substrate. For example, after dissolving a vinyl carbazool-based polymer in xylene and applying it on a PVA substrate to form a film, the exposure and development steps are completed, and water or a mixed solvent of water (water / ethanol, propyl alcohol, etc.) ) To obtain a vinylcarbazool-based polymer film on which a hologram is recorded. At this time, the substrate does not always need to be dissolved, and may be swollen and peeled off.

The transparent substrate used in the present invention does not necessarily have to be a flat plate.For example, in the case of a spherical surface, a spherical shape is formed on the transparent substrate directly or indirectly by using a molded silicone resin, and a hologram image is formed on the spherical surface. Such as when forming
This is extremely effective for manufacturing a hologram sheet that cannot be formed on a flat surface.

When the transparent substrate is dissolved, the hologram sheet floats in or on the solution and can be easily taken out.

The hologram sheet taken out can be stacked on the transfer material by placing it on the transfer material and drying it. This can be used for a sticking sheet or the like to be stuck to another object. If the hologram sheet is laminated on the transfer material to such an extent that it can be peeled off, it can be used as a transfer sheet.

The transfer material used in this case is not limited at all,
Known ones can be widely used, and may be appropriately selected according to the purpose and use.

When the transfer material back surface is to be attached to an object, aside from the case where the transfer transfer plate itself has an adhesive ability, in the present invention, an adhesive layer exhibiting tackiness or an adhesive layer having an adhesive ability is previously formed on the transfer material back surface. It is convenient to stack them. The material of the pressure-sensitive adhesive layer and the adhesive layer can be selected from substantially any material in consideration of the material to be transferred and the transparency.

Also, glue on hologram film or other objects,
An adhesive layer may be attached, and the film may be attached to another object. As typified by the use of such an adhesive layer, particularly when the hologram film is adhered to the object, only the material to be transferred is easily peeled off due to the adhesive force. Available to However, it can be used even in the attached state.

The material of the adhesive layer and the adhesive layer that can be used in such a case is a material that does not adversely affect the hologram film and that does not itself react chemically and physically with the hologram film to harm the hologram film. It may be appropriately selected and used.

The adhesive layer, the adhesive layer, for example, the above properties from acrylate polymer, vinyl acetate polymer, α-cyanoacrylate, urethane adhesive, rubber adhesive, epoxy adhesive, etc. Satisfaction can be selected and used, for example, when polyester is used, acrylate, butyl acrylate,
When copolymerizing 2-ethylhexyl acrylate and ethylene, these compositions are appropriately changed and used,
The characteristics are adjusted and used as needed so as to obtain a desired effect.

To provide the adhesive layer and the adhesive layer, depending on the form, a method of directly applying the film onto the hologram film, a method of temporarily forming a film by casting or the like onto the hologram film 2 or a method of bonding the film is used. It may be appropriately selected and used.

In addition, when the thing made by the present invention is brought into close contact with another thing, depending on the type of the adhesive and the adhesive, 200 ° C. or less, if the pressure is 100 kg / cm ² or less, heating and pressing may be performed. .

Also, such as when used for transfer, when it is desired to reduce the adhesion between the material to be transferred and the hologram film, in order to increase the peelability of the material to be transferred in advance, for example, TSW820,
A known method such as treatment with a known silicone compound such as TSW831 or a Teflon-based oligomer may be used. For the same purpose, a release layer may be interposed between the two.

The release layer according to the present invention is for making the hologram film easier to peel.

As the release layer used for such a purpose, for example, the surface tension of the hologram film (30 to 35 dyne / cm when an N-vinyl carbazole polymer is used)
Has a surface tension that is large or small enough to obtain good peeling conditions. For example, a layer made of a polymer or a layer made of a low-molecular surface modifier called a silane coupling agent or a titanium coupling agent can be used.

Specific examples of the material that can constitute the release layer include polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyfluoroethylene-propylene, and polyorganosiloxane; and silane cups such as γ-glycidoxypropyltrimethoxysilane and vinyltrimethoxysilane. Ring agent; titanium coupling agent and the like can be mentioned.

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

A protective layer may be provided on the hologram film as needed. It is desirable that the protective layer is such that when observing the image of the hologram film through the protective layer, it does not prevent good observation of the image.

The protective layer is provided as a layer made of polyvinyl alcohol, polyfluoroethylene-propylene, polyvinylidene chloride, or the like, for example, in the case where oxygen transmission through the protective layer is controlled to prevent the hologram film from being deteriorated by oxidation. be able to. The protective layer for preventing abrasion due to friction or the like may be formed, for example, by forming a polysiloxane ladder-type polymer layer or an epoxy resin layer directly on the hologram film, or by forming various resin films on which these treatments are applied. It can be formed by laminating on a hologram film.

When forming the protective layer, for example, a triazole derivative such as 2- (hydroxyphenyl) benzotriazole, a triazine derivative such as 1,3,5-tris (2'hydroxyphenyl) triazine, a resole seal monobenzoate, etc. Various protective agents, such as a benzophenone derivative or the like, are added to the layer to form various protective functions. May be.

Further, in addition to the above-mentioned materials, a metal or metal oxide such as InO, Al ₂ O ₃ , Al, and An may be deposited on the hologram film to a thickness of about 50 to 1000 ° to form a protective layer.

The protective layer, the adhesive layer, the adhesive layer, and the like may be formed in the course of the process without impairing the basic steps of the present invention.

〔Example〕

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

Example 1 A 10% by weight aqueous solution of polyvinyl alcohol (Gohsenol GH23 manufactured by Nippon Gosei Co., Ltd.) was applied to a film (about 50 μ
m) Prepared and made poly (N-vinylcarbazole) in the dark
A solution in which 2.5 g and 0.2 g of carbon tetraiodide were dissolved in 30 g of monochlorobenzene was applied using a spinner (Mikasa Spinner, 1H-2) and then dried to obtain a hologram-forming photosensitive agent layer having a layer thickness of 5.0 μm. Was.

Measure the absorbance of the obtained photosensitive agent layer with a spectrophotometer UVIDEC-650
(Manufactured by JASCO Corporation) and found to have an absorption edge of up to 560 nm.

An Ar laser (514.5 nm) was used for the sensitizer layer, and the light intensity ratio was 1: 1 (the sum of the light intensities of both beams was 15 mJ / cm ² immediately before the incidence).
The image corresponding to the desired object was recorded according to the Denisshuk method under the following conditions.

After exposure, the photosensitive agent layer is sequentially processed in the following steps (1) to (4), and a Lippmann type reflection hologram in which a desired image is recorded on a substrate is provided so as to be transferable on a base material. A shaped hologram was obtained.

After immersion in toluene at 20 ° C for 2 minutes, immersion in xylene at 30 ° C for 3 minutes, immersion in n-heptane at 25 ° C for 3 minutes, drying and development, immersion in warm water at 70 ° C for 105 minutes, and PVA After dissolution and removal, a poly (N-vinylcarbazole) -hologram film was obtained.

The obtained hologram is approximately 3 to light of 514.5 nm wavelength.
It has a spatial frequency of 000 lines / mm and a diffraction efficiency of 88%.
It was a volume phase hologram hologram having a transmittance of 90%.

Example 2 Polyvinylpyrrolidone, molecular weight 360,000 (Tokyo Kasei)
Was used in place of polyvinyl alcohol to obtain a hologram sheet in the same manner as in Example 1. The performance was not different from that of Example 1.

Example 3 A hologram sheet was formed in the same manner as in Example 1, except that a polyvinyl alcohol film was formed in a cylindrical shape with a radius of 10 cm, and a sensitizer layer was formed while rotating the cylinder thereon. Its performance was not different from that of Example 1.

Example 4 A hologram sheet was obtained in the same manner as in Example 1, except that polyacrylamide was used as a transparent substrate and water was used as a solvent for dissolving the same. Its performance was not different from that of Example 1.

Example 5 (Performance test as transfer sheet) The holograms obtained in Examples 1 and 4 were placed on a polyester film and dried to obtain a hologram transfer sheet.

Adhesive Acrylic acid emulsion polysol AB-412BN
(Manufactured by Showa Polymer Co., Ltd.) was applied on a structural paper and dried. The hologram transfer sheet was brought into contact with the hologram surface, and a pressure of ² kg / cm ² was applied thereto from above using a roller to peel off the polyester film. The performance of the hologram did not change at all.

[Effects of the Invention] According to the present invention, a hologram sheet having a volume phase which is extremely effective for expanding the use of a volume hologram, that is, can be used for transfer, pasting, and the like can be easily produced. INDUSTRIAL APPLICATION This invention can be utilized suitably especially for manufacture of a hologram sheet which has a special shape other than a flat plate. Moreover, the resulting hologram sheet is excellent in terms of overall efficiency, such as diffraction efficiency and light deterioration, and is sufficiently satisfactory for practical use.

Claims (5)

(57) [Claims] 1. A photosensitizer layer comprising a vinyl carbazole-based polymer as a main component is laminated on a transparent substrate made of a polymer, exposed and developed, and then the transparent substrate is dissolved and the vinyl carbazole is substantially dissolved. A method for producing a volume phase hologram sheet, comprising immersing the transparent polymer in a solvent that does not dissolve the system polymer and dissolving and removing or swelling and peeling the transparent substrate. 2. The method according to claim 1, wherein said transparent substrate is made of a water-soluble polymer. 3. A photosensitizer layer comprising a vinyl carbazole-based polymer as a main component is laminated on a transparent substrate made of a polymer, exposed and developed, and then the transparent substrate is dissolved and the vinyl carbazole is substantially dissolved. Immerse in a solvent that does not dissolve the system polymer, dissolve and remove the transparent substrate or swell and peel,
A method for producing a volume phase hologram, comprising obtaining a volume phase hologram sheet and laminating the sheet on a transfer object. 4. The method according to claim 3, wherein said transparent substrate is made of a water-soluble polymer. 5. The method according to claim 3, wherein said transfer object is paper, metal, plastic or ceramic.