JPS6147425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for mass duplicating holograms.

With the development of lasers as coherent light sources, holograms in which three-dimensional stereoscopic information is recorded on two-dimensional recording materials have been manufactured. however,
Developmental research on hologram production to date has mainly focused on improving methods for recording objects, and although there have been one or two proposals for mass supply of holograms, it has been considered difficult. The reason for this is as follows.

First of all, the essential principle of creating a hologram is to record interference fringes of coherent light on the photosensitive material surface (dry plate). The positional relationship between the original plate (master) and the dry plate is as follows.
If there is vibration or movement on the order of the wavelength of light, interference fringes cannot be formed. Therefore, repeated recording and duplication are difficult, and mass production of holograms is difficult. In addition, optical duplication from an original plate requires darkroom work, and only repeats one-to-one duplication, which is not suitable for mass production.

In response, a method has been proposed in which the original plate is made of metal and the fine interference fringes constituting the holographic information are pressed onto the surface of the polymer material. Manufacturing of blazed
holography) “Appl.Phys.Lett. 12 , 316―318
(1968)) This technique is typically performed as follows. That is, first, interference fringes are recorded on a photoresist coated on a glass plate, and after development, gold is deposited on the uneven interference fringes formed on the resist. Next, nickel plating is applied to this gold evaporated surface using a nickel counter electrode in a sulfamic acid nickel plating bath to form a mother plate.
make. After that, a master (original version) is created from the mother using the same plating process. Next, this nickel original plate is pressed onto a thermoplastic resin sheet to record interference fringes to form a hologram.

This hologram manufacturing method has the advantage of being more easily mass-produced than conventional methods that employ optical methods, since the process of duplicating the product hologram from the original is performed by press working. however,
This method uses the thermoplasticity of the resin to record minute interference fringes, so it is difficult to control the temperature during pressing, and due to the springback of the resin, it may change over time.
There is a drawback that the diffraction efficiency of the produced hologram decreases due to temperature changes.

In view of these circumstances, the present invention aims to provide a method and apparatus for producing holograms in large quantities and with high precision.

According to the research of the present inventor, such purpose is
Although it is similar to the method of pressing the original resin sheet described above, it utilizes the electron beam curability of the resin instead of its thermoplasticity to shape the resin for recording fine interference fringes, and It has been found that this can be achieved by harmonizing the mold release effect and the shaping effect through two-stage irradiation.

That is, in the method for manufacturing a hologram of the present invention, an electron beam curable resin layer coated on a base sheet,
Only the surface layer is cured by preliminary exposure to an electron beam, and then a printing plate having fine irregularities constituting holographic information is pressed onto the resin layer, and at the same time as this pressing, the resin layer is again irradiated with an electron beam and cured. It is characterized by completing the following.

Further, the continuous hologram manufacturing apparatus of the present invention includes:
A supply device for a base sheet on which an electron beam curable resin layer is formed, and a supply device for preparing only the surfaces of the resin layers sequentially arranged on the resin layer forming surface side of the base sheet along the flow direction of the base sheet. A first electron beam irradiation device for curing, an original plate having holographic information as a fine uneven pattern for press-transferring to the pre-cured resin layer, and a base sheet on a side opposite to the side on which the resin layer is provided. It is characterized by comprising a second electron beam irradiation device provided on the surface side facing the original plate.

The present invention will be explained in more detail below.

As a method for obtaining the master plate used in the present invention, any known method can be used, including, for example, the method described in the above-mentioned Sheridon document.

Preparation of the master plate, more commonly a dichromate gelatin plate;
Using a silver dry plate, etc., a He-Ne laser (wavelength 632/
8nm), Ar laser (wavelength 488nm, 543nm), etc., using an optical system including an appropriate lens, mirror, or beam splitter to obtain an object beam and a reference beam, and irradiate these onto the photosensitive layer of the dry plate. Recording is performed by doing this. after that,
A hologram is obtained by performing treatments such as hardening, dehydration, and drying. This becomes the mother (mother version).

Preparation of original plate As described above, a metal original plate may be obtained from this mother plate by a method including metal vapor deposition by the method described in Sieridon. However, in order to obtain a cylindrical metal master plate, it is preferable to manufacture the master plate by the following method, which includes the use of a carboxylic plate and etching.

This method is implemented as follows, by way of example.

That is, as shown in FIG. 1, a gelatin layer 2 of a carbon tissue A is formed on a dark-colored mount 1 such as a red iron mount, and a gelatin layer 2 having a thickness of, for example, 10 to 300 μm is sensitized with dichromic acid in advance. The photosensitive resin layer 4 of the mother plate B, which has the photosensitive resin layer 4 containing holographic information as minute interference fringes, is closely attached to the glass substrate 3.
By irradiating the laser beam 5 from the mother plate B side, the holographic information of the mother plate B is transferred to the gelatin layer 2 of the carbon tissue A. It is considered that holographic information is recorded in the gelatin layer 2 as a latent image of fine interference fringes 6, as shown in FIG. Such interference fringes 6 may be recorded on the entire surface of the gelatin layer 2, or may be recorded on a portion thereof after performing appropriate masking.

The carbon tissue A with the holographic information recorded thereon is wound around the metal plate cylinder. For example, as shown in FIG. 3, an alcohol aqueous solution 11 is applied onto a Cu gravure plate cylinder 13 via a rubber roll 12, and two gelatin sides of carbon tissue A are brought into close contact with this applied surface. This is done by pressing the guide rolls 14a, b, c with a rotating belt 16. The alcohol aqueous solution has an alcohol content of 2 to 20%, especially 5 to 12%, and is preferably used at 16 to 24°C, especially 20 to 22°C, and can be used not only for roll coating as shown in the figure, but also for roll coating as shown in the figure.
You can also spray coat it. Further, the adhesion of the carbon tissue A to the plate cylinder 13 is preferably carried out under pressure.
It is carried out at a rate of 200g/cm ² to 7.5Kg/cm ² and a speed of 15 to 80cm/min.

After confirming complete adhesion of the carbon tissue A to the plate cylinder 13, the mount 2 is peeled off. To do this, first, water at a temperature of 15 to 65°C is gradually oozed from the mount 2 side while gradually increasing the temperature, and then the mount is removed.

After peeling off the mount, gelatin in the unexposed area is dissolved and removed by flowing hot water, preferably at 32 to 58°C, onto the gelatin layer 2 attached to the plate cylinder, and then a 50 to 100% alcohol aqueous solution is added while rotating the plate cylinder. 1 to 3
Wash twice. Next, the gelatin is rapidly dried for 10 to 40 minutes while blowing hot air at 90 to 190°C to harden the gelatin. The development start process up to this point is
It is preferable to carry out the recording within 24 hours, especially within 3 hours after recording the holographic information on the carbon tissue. Also, the gelatin layer in this state is sensitive to humidity, so it is best to keep it dry.

The cross section of the surface layer of the plate cylinder 13 on which the gelatin layer 2 formed in this way is formed is as shown in FIG. 4 when a Ballard method gravure plate cylinder is used as the plate cylinder 13. Ag layer 17,
A gelatin layer 2 having holographic information as minute cracks 19 is formed on an outer Cu layer 18. Therefore, when the plate cylinder is immersed in an appropriate etching solution in this state, the etching solution first passes through the cracks 19 in the gelatin layer 2.
The etching liquid that has passed through the gelatin also reaches the Cu surface 18 after a while. In this way, the etching speed differs depending on where gelatin is attached and where it is not, and where the thickness of the gelatin layer is different, and the etching surface pattern is due to the interference of gelatin in the areas that are in close contact with the Cu surface 18. The stripes will be recorded. FIG. 5 shows a conceptual cross-sectional view of the surface layer of the plate cylinder 13 after the gelatin layer has been removed after etching. The present inventor discovered that the surface layer etching pattern formed on the Cu surface 18 in this manner is similar to the pattern of a commonly-known blazed hologram.

For etching, use a Cu plating layer on the outside of the plate cylinder 13 of 1.0 to 40μ, especially 2 to 10μ,
Be'35-44°, especially Be'39-42°, using ferric chloride solution as an etching solution for 5-30 minutes, especially 10-42°.
It is preferable to do this for 15 minutes. Immediately after etching, the gelatin is washed with water, and the gelatin is sufficiently dissolved and removed using warm water of 30 to 45°C to expose the Cu surface 18.

Furthermore, in order to protect the Cu surface and improve the mold releasability from the resin described later, 0.1 to 4μ, especially
It is preferable to apply Cr plating with a thickness of 0.2 to 1.0μ.

In this way, a preferable hologram master plate for use in the present invention was obtained.

Reproduction of hologram In order to reproduce a hologram from the hologram master plate obtained as described above, it is preferable to use the method shown in FIG. The following method is adopted using such a device system.

That is, it is made of paper or preferably biaxially stretched plastic film, etc., and has a thickness of 10 μm or more.
While feeding out the base sheet 20 of about 300 μm from the supply roll 21 at a rate of 5 to 50 m/min, preferably 15 to 35 m/min, the electron beam curable resin 23 is applied via the application roll 21 at, for example, 2.0 to 6.0 g/m ^{2 .} or in a layer thickness of 20 to 300μ. Although not shown, the base sheet 20 may be printed by adding an appropriate printing roll prior to applying the electron beam curable resin.

The base sheet 20a coated with the electron beam curable resin in this manner is then introduced into the nitrogen chamber 24, where the first electron beam provided facing the electron beam curable resin coated surface of the base sheet 20a is introduced. The electron beam 26 is irradiated from the irradiation device 25 to harden only the surface layer 27 of the electron beam curable resin layer 23 (sixth
(Fig. 7).

Next, the base sheet 20a having the surface hardened electron beam curable resin layer is introduced into the second nitrogen chamber 24a, where the electron beam curable resin layer 23 is provided on the side of the base sheet 20a having the electron beam curable resin layer 23. With the gravure cylinder-shaped hologram original plate 30 created as described above, the fine irregularities 31 constituting the holographic information are pressed against the hardened thermosetting resin layer 23 on the surface layer, and the corresponding holographic information becomes the fine irregularities 32. is recorded in the electron beam curable resin layer 23 or its cured product layer 27. Pressure is applied by a pair of tension rolls 30
Adjust by a and b. On the other hand, the base sheet 20a
An electron beam 26 is irradiated onto the electron beam curable resin layer 23 through the base sheet 20 from a second electron beam irradiation device 33 provided opposite to the side on which the hologram original plate 30 is provided. A cured product 27 covering the entire layer is provided (FIGS. 6 and 8).

Finally, the hologram continuous sheet 34, which is formed by recording holographic information as fine irregularities 32 on the surface layer of the cured resin layer 27 of the base sheet 20a thus formed, is wound up by a winding roll 35. A product hologram is obtained by cutting this sheet 34 into appropriate dimensions.

In the case of the present invention, as can be clearly seen with reference to FIGS. 7 and 8, when viewed from the wavelength order of light, such as the surface of the base sheet 20 made of paper or resin film, The electron beam curable resin layer 23 is coated and formed, and the surface layer 27 is irradiated with an electron beam.
When cured, a smooth, high-gloss surface is obtained. The thus formed resin layer, in which only the surface layer is hardened, has an ideal balance of overall softness suitable for imparting fine irregularities of interference fringes and surface releasability. Since the entire resin layer is cured by being irradiated with the second electron beam almost simultaneously with the shaping, springback, which occurs when molding using thermoplastic resin, is hardly a problem. Therefore, the fine irregularities of the interference fringes formed on the original plate 30 are accurately transferred to the cured resin layer 27.

The electron beam curable resin used in the present invention is a radical curable composition and usually consists of an oligomer having double bonds alone or in a mixture with a vinyl monomer. Vinyl monomers are viscosity modifiers to enable coating on films, and
When curing, it copolymerizes with oligomers. Oligomers include unsaturated polyester resins, acrylic resins, urethane-modified unsaturated polyesters, silicone-modified unsaturated polyesters, vinyl urethane resins, epoxy-modified unsaturated polyesters, acrylic-modified epoxy resins, etc. alone or as a mixture of two or more. Can be used. In addition, vinyl monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate,
n- and i-propyl acrylate, n- and i-propyl methacrylate, n-, i-acrylate
- and t-butyl, n-, i- and t-butyl methacrylate, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, vinyltoluene, ethylene glycol diacrylate, ethylene glycol diacrylate Methacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene Glycol dimethacrylate, 1,4-butylene glycol diacrylate, 1,4-butylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, divinylbenzene, diallyl phthalate, trimethylolethane triacrylate, trimethylolethane triacrylate Methacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, glycerin triacrylate,
Compounds such as glycerin trimethacrylate, pentaerythritol tetraacrylate, and pentaenethritol tetramethacrylate can be used alone or as a mixture of two or more.

In addition to the above-mentioned roll coating method, methods such as a gravure coating method and a flexographic reverse method may be appropriately used to apply these electron beam curable resins to the base sheet 20.

As the first and second electron beam irradiation devices, either a linear filament curtain type electron beam irradiation device or a scanning type electron beam irradiation device can be used. However, if the second electron beam irradiation device uses a scanning method, if the electron beam is incident obliquely on the fine irregularities of the cylindrical original, it will create shadows and create unexposed areas in the electron beam curable resin. Therefore, the curtain method is preferable.
An example of a suitable curtain type electron beam irradiation device is a linear filament type manufactured by ESI (Energy, Science, Inc.).

The energy of the irradiated electron beam is 10 to 1000 KeV
In particular, the pre-exposure is preferably in the range of 15 to 65 KeV, and the second electron beam irradiation to complete curing is preferably in the range of 100 to 300 KeV. As a guideline, the preliminary irradiation energy is preferably in the range of 1/10 to 1/3 of the energy required for curing.

In carrying out the present invention, the original plate does not necessarily have to be cylindrical, and the invention can also be carried out by pressing a flat original plate against a pre-cured electron beam curable resin layer on a base sheet. At this time, in the apparatus system shown in FIG. 6, the supply of the base sheet is performed intermittently. The meaning of "continuously" in the continuous hologram manufacturing apparatus of the present invention includes such intermittent cases. However, it goes without saying that the apparatus system shown in FIG. 6 is more preferable in that it allows complete continuous production.

As described above, according to the present invention, an electron beam curable resin is used as the resin when a hologram master having a fine uneven pattern forming holographic information (interference fringes) is pressed onto a resin surface to reproduce a hologram. , and two-stage electron beam irradiation, it is possible to precisely transfer a fine uneven pattern. Particularly, by using a cylindrical hologram master plate obtained by a series of methods characterized by the combination of carbon tissue and etching, complete continuous production of holograms becomes possible.

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

Example 1 Using a gravure roll with the apparatus shown in FIG. 6, an electron beam curable resin (Mobil Chemical
Co., Ltd. 78E145B) was applied at a rate of 5.2 g/ ^m2 , and while being wound at a speed of 30 m/min, the surface of the electron beam curable resin was pre-irradiated with an electron beam at 12.5 kV and 30 mA in a nitrogen atmosphere. The layer was cured to about 0.4μ, and pressed with a cylindrical hologram original plate having interference fringes with a pitch of 3μ.At the same time, an electron beam was applied from the back of the paper in a curtain shape under the energy conditions of 175kV and 30mA.
A dose of 2.5 Mrad was irradiated. As a result, the resin layer was deformed by the irregularities of the original plate, and at the same time was cured, and interference fringes were recorded on the paper surface, and at the same time, the surface was given a glossy effect. The covers of the weekly newspapers produced in this way were glossy, and the silver-printed areas diffracted light due to interference fringes, making them appear rainbow-colored, creating an extremely fantastic effect.

Example 2 A biaxially stretched polypropylene film with a thickness of 25μ was deposited with aluminum to a thickness of 600 Å using a continuous two-tank vacuum evaporation apparatus while maintaining the vacuum level of the evaporation tank at 10 ^-5 Torr. And so.

Electron beam curable resin (Mobil) is applied to the film.
78E145B (manufactured by Chemical) was applied at an amount of 4.5 g/m ² using a gravure roll, and while being wound at a speed of 30 m/min, an electron beam was applied at 13 kV and Preliminary irradiation at 30 mA was used to harden only the surface layer, and a cylindrical hologram master was created by recording lattice-like interference fringes with a vertical and horizontal pitch of 2 μ on the entire surface of the carbon tissue. After applying interference fringes, the resin was completely cured with an electron beam of 175 kV and 30 mA. When this film was made into a bag for cosmetics, light was diffracted on the surface of the bag, giving it a rainbow-colored appearance, making the bag extremely appealing.

Example 3 A subject with the letters “DNP” on the cover of a gravure-printed catalog made in a concave shape.
It was recorded on a hologram, and using this hologram as an original plate, it was transferred to the gelatin layer of a carbon tissue as shown in FIG. At this time, the direction of the reference light incident on the original was set to be opposite to the direction of incidence of the reference light when recording the subject. A cylindrical hologram original was made from the carbon tissue by the method described in the text. After examining the hologram portion of the original plate and the printed character portion using the apparatus shown in FIG. 6, a hologram was recorded under the electron beam irradiation conditions described in Example-1.

When you look at this catalog under light (point light source),
The text "DNP" appears to protrude approximately 1 cm from the cover, further increasing the value of the catalog.

Example 4 Electron beam curable resin (78E145B manufactured by Mobil Chemical) was applied to 80 g/m ² high-quality paper (0.75 m width roll) using a gravure roll in an amount of 45 g/m ² .
In a nitrogen atmosphere while winding at a speed of m/min.
With a 175kV, 30mA electron beam curtain,
Paper with a smooth resin-coated surface was obtained by irradiating with a dose of 2.5 Mrad.

This was then used in a continuous two-tank vacuum evaporation apparatus to maintain the vacuum level of the evaporation tank at 10 ^-5 Torr, and aluminum was evaporated to a thickness of 600 Å to obtain a evaporated paper.

The electron beam curable resin was again coated on this vapor-deposited paper under the conditions described in Example 2, and a hologram was recorded on the surface of the vapor-deposited paper using the apparatus shown in FIG. The vapor-deposited paper with the diffraction grating (hologram) produced in the above manner has a surface that exhibits a completely metallic luster with the metal layered evenly and closely on the resin-coated surface. , when exposed to light, the light is emitted on that surface.
It reflects nearly 80%, increasing the diffraction effect of the diffraction grating on the surface. Moreover, even when the resin was cured by electron beam irradiation, this vapor-deposited paper remained flexible and did not lose its properties as paper, and had good moldability.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the mother plate-carbon tissue laminate showing the transfer process from the hologram mother plate to the carbon tissue, Figure 2 is a sectional view of the carbon tissue after transfer, and Figure 3 is the carbon tissue laminate. 4 and 5 are cross-sectional views of the surface layer of the plate cylinder before and after etching, respectively. FIG. 6 is a side view showing the process of attaching the plate to the plate cylinder, and FIG. 6 is a layout of various parts showing an example of the hologram manufacturing apparatus of the present invention. 7 and 8 are enlarged cross-sectional views of the base sheet viewed from the side, conceptually showing changes in the two nitrogen chambers of FIG. 6. A...Carbon tissue, (1...mounting paper, 2...gelatin layer), B...hologram mother plate (3...substrate, 4
...photosensitive agent layer), 5...laser light, 6...interference fringe latent image, 13...plate cylinder, 15...pressing belt, 16...inside
Cu layer, 17...Ag layer, 18...Outer Cu plating layer, 1
9... Gelatin layer crack, 20... Base sheet, 2
3... Electron beam photosensitive resin layer, 24... Nitrogen chamber, 25, 33... Electron beam irradiation device, 26... Electron beam, 27... Cured resin, 30... Hologram original plate, 3
1...Minute irregularities forming holographic information, 32
...Transferred unevenness, 34...Hologram.

Claims (1)

[Claims] 1. An electron beam curable resin layer coated on a base sheet is pre-exposed to an electron beam to harden only the surface layer, and then has a finely uneven surface constituting holographic information. Pressing the original plate onto the resin layer,
A method for manufacturing a hologram, characterized in that simultaneously with this pressing, the resin layer is irradiated with an electron beam again to complete curing. 2. A supply device for a base sheet on which an electron beam curable resin layer is formed, and a supply device for supplying only the surface layer of the resin layer sequentially arranged on the resin layer forming surface side of the base sheet along the flow direction of the base sheet. A first electron beam irradiation device for pre-curing, an original plate having holographic information as a fine uneven pattern for press-transferring to the pre-cured resin layer, and a base sheet opposite to the surface on which the resin layer is provided. and a second electron beam irradiation device provided on the side of the pressing plate facing the pressing plate. 3. The apparatus according to item 2 above, wherein the original plate is obtained by etching a metal plate cylinder through a hardened gelatin layer of a carbon tissue containing holographic information provided on the metal plate cylinder.