JP2000221869A - Production of hologram molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the deformation of sheets by deformation of organic layers, such as adhesives, by the heat treatment after combination of the sheets as far as possible. SOLUTION: The production of a hologram molding 8 to perform heat development after hologram exposure is executed before or after a laminating stage of the second substrate 3 of a hologram laminate formed by successively laminating a first substrate 5, a hologram photosensitive layer and the second substrate 3 is carried out in this process. The absolute value of the difference in the coefficients of thermal expansion between the first substrate 5 and the second substrate 3 is so specified as to be kept, within a range of <=100×10-7/10 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hologram formed body in which a hologram sensitive material is laminated between substrates such as thin glass.

[0002]

2. Description of the Related Art In electronic parts and optical parts, there are substrates provided with various functions, the surfaces of which are coated with thin glass.
For example, a laminate for forming a volume hologram is one example. Volume holograms are used for 3D image display, measurement, optical elements, etc., and industrially, it is necessary to duplicate the same volume hologram in large quantities. Conventionally, this duplication is performed as follows. Was. In the following description, a hologram material is assumed to be a typical volume hologram material such as a photopolymer such as "OMNIDEX" manufactured by DuPont, USA.

[0003] A volume hologram master and a volume hologram forming substrate (a glass substrate coated with a volume hologram forming resin composition layer) are superposed and exposed.
The hologram master is duplicated on the volume hologram-forming resin composition layer by performing each of the steps of ultraviolet irradiation (= decomposition and polymerization of the photopolymerization initiator) and heat treatment (= diffusion transfer of the photopolymerizable compound). .

[0004] Conventionally, the hologram thus copied is
Furthermore, a volume hologram forming substrate similar to the above is prepared, and the hologram layer side is brought into contact with the volume hologram forming substrate and exposed to light, thereby producing a volume hologram.

[0005] Regardless of the production of a master for duplication and the use of mass replication for producing a hologram, a hologram in which a photocurable resin composition layer for hologram formation is laminated on a substrate is required. Using a photosensitive material for formation, the photocurable resin composition layer is exposed to hologram information, and then a heat treatment is performed to move unreacted photocurable resin to the polymerized portion. Specifically, after exposing hologram information to a hologram photosensitive material having a volume hologram-forming resin composition layer laminated on a substrate, a transparent substrate is placed on the volume hologram-forming resin composition layer via an optical adhesive. After stacking, heat treatment is performed.

[0006]

However, for example, in a heat treatment for manufacturing a substrate covered with a thin glass on a volume hologram layer, since the substrate coated with the thin plate is heated alone, the bonding is not performed. There is a problem that the deformation of the agent layer and the intermediate layer deforms the thin plate on the surface.

In particular, in the case of an optical element using a volume hologram as one of the organic layers due to this deformation, the angle of diffraction in the plane of the volume hologram is (Bragg angle:
Since the incident angle at which the first-order diffraction efficiency at the time of incidence at a specific wavelength is maximized is different between the central portion and the peripheral portion, a difference in brightness (the peripheral portion becomes darker) occurs as shown in FIG. This phenomenon is called shading. In order to suppress this shading, the difference between the absolute values of the Bragg angles of the central portion and the peripheral portion must be 2 ° or less.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a hologram having a hologram coated with a thin plate in which deformation of the thin plate due to deformation of an organic layer such as an adhesive due to heat treatment after the combination of the thin plates is eliminated as much as possible. An object of the present invention is to provide a method for manufacturing a material substrate.

[0009]

SUMMARY OF THE INVENTION The present invention solves a conventional fatal defect by suppressing deformation of a thin plate due to deformation of an organic layer such as an adhesive. The invention according to claim 1 includes a first substrate, a hologram photosensitive material layer, and a second substrate.
In the method for manufacturing a hologram-formed body in which hologram exposure is performed before or after the step of laminating the second substrate of the hologram laminate obtained by sequentially laminating the first and second substrates, the first substrate and the second substrate are subjected to heat development. The absolute value of the difference between the expansion coefficients of the substrates is 100 × 10 ⁻⁷ / ° C. or less. According to a second aspect of the present invention, in the hologram laminate, one or more intermediate layers other than at least the hologram photosensitive material layer are further laminated between the first substrate and the second substrate. According to a third aspect of the present invention, the third substrate is further laminated on a surface of the second substrate on which no other layer is formed, and the second and third substrates are laminated with the first substrate.
The absolute value of the difference between the expansion coefficient and the substrate is 100 × 10 ⁻⁷ / ° C.
It is characterized by the following range. In the invention according to claim 4, the adhesion strength between the second substrate and the third substrate is 10 to 10.
It is characterized by being in the range of 10,000 g / cm. The invention according to claim 5 is characterized in that the in-plane deformation of the first substrate and the second substrate during the heat development is in the range of 0 to 1 mm. The invention according to claim 6 is characterized in that the respective in-plane deformations of the sum of the first substrate, the second substrate, and the third substrate during the heat development are in the range of 0 to 1 mm. The invention according to claim 7 is characterized in that the third substrate is a surface plate used in a manufacturing process. The invention according to claim 8 is characterized in that the substrate is a combination of at least one of glass, plastic and ceramic, and at least one substrate of the hologram forming body is light-transmissive. According to a ninth aspect of the present invention, the hologram sensitive material layer has a binder resin at least selected from polyvinyl acetate, cellulose acetate butyrate, methyl methacrylate copolymer, polymethyl methacrylate, and polyvinyl butyrate, and has 2-phenoxyethyl acrylate and p-chlorophenyl. Acrylate, N-vinylcarbazole, at least a monomer selected from N-phenylmaleimide, an initiator, a sensitizing dye, a chain transfer agent,
It is characterized by comprising a plasticizer composition. A tenth aspect of the present invention is characterized in that the intermediate layer includes an adhesive layer. An eleventh aspect of the present invention is that the condition of the heat development is a temperature of 10
0 to 200 ° C., and heating time is 0.5 to 5 hours
It is characterized by being in the range. The invention of claim 12 is
The relationship between the respective areas S1, S2 and S3 of the first substrate, the second substrate and the third substrate is S1, S2> S3. A thirteenth aspect of the present invention is characterized in that the flatness of the surfaces of the second substrate and the third substrate is 0 to 1 μm.

[0010]

Embodiments of the present invention will be described below. 1 to 6 are cross-sectional views of a main part for illustrating a method of manufacturing a hologram-formed body according to the present invention. As shown in FIG. 1, a platen 2 is placed on an air chuck 1 made of aluminum or the like for fixing an object to be coated, which is installed in a rotary coating machine as a base.
Is fixed by vacuum suction. The platen 2 may be fixed by means other than vacuum suction, such as mechanically. The front surface of the surface plate 2, that is, the surface opposite to the surface fixed with the air chuck is preferably a flat surface with improved flatness, and has a flatness of 0.5 μm or less. Use a BaK50 glass made by Shot. When the planarity is increased in this manner, the substrate 3 which is an object to be coated is brought into contact with the surface plate 2 without any gap in the substrate 3 contacting step described below, so that the substrate 3 can be adhered without an operation such as vacuum suction. Will be kept.

As an example, 65 mm × 65 mm, thickness 1
The platen 2 for placing the thin glass of 00 μm is 53 mm
× 53 mm, thickness 6 mm. Incidentally, the size of the substrate is 65 mm × 65 mm and the thickness is 1.1 mm. Surface plate 2
Is desirably 0.5 mm to 20 mm.
The material of the surface plate 2 is preferably a material having an expansion coefficient similar to that of the glass of the substrate 5 described later and transmitting ultraviolet light for curing the adhesive. For example, trade names are borosilicate glass, 7059, 1737, AF45, Pyrex, Tempax, 8337B, 8338, BK7, I
R5088, IR5188, 0700, 0709, Ba
K50 and the like.

FIG. 2 shows a state in which the substrate 3 is placed on and adhered to a fixed surface plate. The above-mentioned close contact means that the height difference Δx between the surface of each of the surface plate 2 and the substrate 3 is 1
This means that when substrates having a high flatness of not more than μm are stacked, an effect such as a self-vacuum suction state is exhibited. Here, the height difference Δx indicates the unevenness and the amount of warpage of the substrate surface. Other laminating methods include a method of vacuum-sucking between the substrates using a vacuum pump or the like from the outside, a method of applying a load or pressure between the substrates, and a method of increasing the adhesion strength between the two using an adhesive. There is.
The material of the substrate 3 is desirably the same as that of the surface plate, but may be a material having a similar expansion coefficient.

FIG. 3 shows a state in which a liquid adhesive is applied to the surface of the substrate 3 by dripping or the like, and the substrate 5 to be bonded thereon is applied thereto.
Is shown. The surface of the substrate 5 is exposed to a hologram pattern with a laser, and then irradiated with ultraviolet rays (decomposition of a photopolymerization initiator) to form a volume hologram layer 6 and a protective film 7.
Is formed. The glass material of the substrate 5 is preferably the same as that of the surface plate, but may be a material having a similar expansion coefficient. When the liquid adhesive 4 is dropped using a dispenser or the like, discharge conditions are set so that the amount is sufficient and not excessive for bonding, and care is taken so that air bubbles are not mixed. Depending on the weight of the substrate 5 and the discharge amount of the adhesive 4, the adhesive spreads somewhat due to the weight of the substrate, resulting in a state as shown in FIG.

Subsequently, when the spinner is rotated at a high speed,
The adhesive spreads to the periphery between the substrate 3 and the substrate 5, and the thickness of the adhesive decreases accordingly, and the excess adhesive protrudes from the periphery, so that the excess adhesive is shaken off by centrifugal force. At this time, the thickness of the adhesive can be controlled by adjusting the viscosity of the adhesive, the number of rotations (= number of rotations / minute) with respect to the elapsed time, and the rotation time. Through the above steps, the substrate 3 and the substrate 5 are laminated with the adhesive.

FIG. 4 shows a state in which the layers are stacked. If the adhesive is curable with ionizing radiation, ionizing radiation (eg,
The adhesive is cured by irradiation with an electron beam or ultraviolet rays. In the subsequent process, it is necessary to peel off the integrated substrate 3 and substrate 5 from the surface plate. Therefore, an ionizing radiation-curable adhesive is used as the adhesive, and the adhesive is sufficiently cured by irradiation with ionizing radiation. It is desirable.

FIG. 5 shows a state of heat treatment (at 140 ° C. for 90 minutes) with the hologram forming body 8 (the substrate 5 and the substrate 3 adhered) and the surface plate 2 kept in contact with each other from the air chuck 1. After the heat treatment, the substrate 8 covered with a thin plate obtained by peeling off the close contact is shown upside down in FIG.

As a result obtained by projecting the hologram forming body 8, the difference between the Bragg angles of the central portion and the peripheral portion was 0.3 °, and no shading was observed. Note that the substrate 5 and the substrate 3 and the substrate 3
The thermal expansion when the surface plate 2 was brought into close contact with the platen was evaluated by visual observation or Bragg angle while changing the type and thickness of the substrate, and the difference in the thermal expansion coefficient between the substrate 5 and the substrate 3 or the substrate 5 and the substrate was evaluated. It was found that the absolute value of the difference in the coefficient of thermal expansion when the platen 2 was brought into close contact with No. 3 was 100 × 10 ⁻⁷ / ° C. or less. At this time, when the in-plane deformation (the amount of deformation in the normal direction to the surface) was evaluated with a Fizeau interferometer, the in-plane deformation of the substrate 5 and the substrate 3 was desirably 0 to 1 mm. It was found that it is desirable that the in-plane deformation in a state where the surface plate 2 is in close contact is also 0 to 1 mm.
Further, the adhesion strength between the substrate 3 and the surface plate 2 was evaluated by a 90 ° peel strength. The adhesion strength between the two can be as high as possible, but in practice, it has been found that 10 to 10,000 g / cm is sufficient.

Examples of OMNIDEX used as the hologram sensitive material used in the present invention are as follows (Source: Magazine, Functional Materials, August 1995, vol. 15, vol.
No8, p51). Binder polymer: 45-65 wt% ・ Cellulose acetate butyrate ・ Methyl methacrylate copolymer ・ Polymethyl methacrylate ・ Polyvinyl butyrate ・ Polyvinyl acetate Monomer: 28-46 wt% ・ 2-phenoxyethyl acrylate ・ p-chlorophenyl acrylate ・ N-vinyl Carbazole (solid) N-phenylmaleimide (solid) Initiator: 1 to 3 wt% Hexaarylbisimidazole derivative (HABI) Sensitizing dye: 0.1 to 0.2 wt% [blue to green] DBC, DEAW, Dimethyoxy-JDI [red] ・ Cyanine dye, squarylium dye Chain transfer agent: 2-3 wt% ・ 2-mercaptobenzoxazole (MBO) Plasticizer: 0-15 wt% ・ Triethylene glycol esters ・ A Diethyl dipinate, tributyl phosphate The substrate may be a combination of at least one of glass, plastic, and ceramic. The intermediate layer includes an adhesive layer. ~ 200 ° C, heating time is 0.
It is desirable to be 5 to 5 hours.

Example 1 The following was prepared as a photosensitive material forming composition. Photosensitive material forming composition: Vinyl butyrate 30 parts by weight Vinyl acetate 30 parts by weight N-vinylcarbazole 37 parts by weight Hexaarylbisimidazole 3 parts by weight A sensitizing dye was added to the photosensitive material forming composition having the above composition.
2. thickness on a glass substrate of 1100 μm thickness (Corning 1737 expansion coefficient 38 × 10 ⁻⁷ / ° C. manufactured by Corning).
A photosensitive material layer of 8 μm was formed.

The separately prepared volume hologram master was placed on the hologram photosensitive layer obtained above, and hologram exposure was performed using an Ar laser light source having a wavelength of 488 nm. After the exposure, an ultra-high pressure mercury lamp (intensity of 300 W) was used to perform 365 nm hologram exposure.
And irradiating it for 2 minutes (exposure 3
000 mJ / cm ² ), and the monomer remaining unreacted after the exposure was cured to obtain a duplicate hologram. A thin plate of transparent glass (Corning 1737, Corning 1737, expansion coefficient 38 × 10 ⁻⁷ / ° C.) having a thickness of 1100 μm was directly bonded to the obtained duplicate hologram using the adhesiveness of the photosensitive layer. A duplicate hologram with a transparent glass sheet attached to it
Heat treatment was performed in an oven at 20 ° C. for 2 hours. When a light was applied to the duplicated hologram after the heat treatment, the hologram was reproduced with high reproducibility and no shading was observed.

[Embodiment 2] Thickness in the same manner as in Embodiment 1.
A photosensitive material layer having a thickness of 3.8 μm was formed. Volume E prepared separately
Place the program original on the hologram photosensitive layer obtained above.
Hologram using an Ar laser light source with a wavelength of 488 nm.
Exposure, and after exposure, ultra-high pressure mercury lamp (intensity 300W)
Take out 365nm light and irradiate for 2 minutes
(Exposure amount 3000 mJ / cm^Two ), Not after exposure
The monomer remaining in the reaction is cured to obtain a duplicate hologram.
Was. UV-curable adhesive on the resulting duplicate hologram
A certain optical adhesive (NOA61, manufactured by Norland) is applied
Using a pinner, apply 5 μm and apply a thickness of 100
μm transparent glass (Shot AF45, expansion coefficient 4
5 × 10^-7/ ° C)
UV irradiation (365 nm, 9 J / cm ^Two )
The adhesive was cured. When the curing of the adhesive is completed,
A duplicate hologram with a light glass thin plate attached to it
Heat treatment was performed in an oven at 20 ° C. for 2 hours. heating
When light was given to the duplicate hologram after processing,
Inspection showed slight shading,
There was no effect.

Example 3 A duplicate hologram was obtained in the same manner as in Example 2. Resin solution (10% aqueous solution) composed of polyvinyl alcohol resin on the obtained duplicate hologram
Was applied by a spinner (1500 rpm) coating method, and dried by heating to form a protective layer of 7 μm. Further, on the protective layer, an optical adhesive (NOA61, manufactured by Norland Co., Ltd.), which is an ultraviolet curable adhesive, was applied for 5 μm using a spinner.
and a thin plate of 100 μm thick transparent glass (AF45, manufactured by Schott Co., expansion coefficient 45 × 10 ⁻⁷ / ° C.) is bonded to the coated surface, and the bonded product is irradiated with ultraviolet rays (36).
5 nm, 9 J / cm ² ) to cure the adhesive. When the curing of the adhesive is completed, the duplicate hologram bonded to the transparent glass sheet is placed in an oven at a temperature of 120 ° C. for 2 hours.
Heat treatment was performed after a certain time. When light was applied to the duplicated hologram after the heat treatment, it was observed that shading was slightly observed by a visual inspection as in Example 2, but the duplicated hologram was not affected.

Example 4 As in Example 3, a protective layer was formed on the obtained duplicate hologram. Next, a glass substrate having a thickness of 1.1 mm (1737, manufactured by Corning Incorporated, expansion coefficient: 38 × 10 ⁻⁷ / ° C.) is set as a surface plate on the air chuck of the spinner. The height difference Δx of the surface of the surface plate is 10
μm. On this platen, a thin glass sheet of 100 μm thickness (AF45 manufactured by Schott Co., Ltd., expansion coefficient 45 × 10 ⁻⁷ /
℃). The height difference Δx of the surface of the thin glass is 50
μm. As described above, since the height difference Δx between the surface of the surface plate and the thin glass is small, the close contact between the surface plate and the thin glass was maintained without vacuum suction. At this time, the adhesion strength is 30 g / c.
m (90 ° peel strength).

Next, an optical adhesive (NOA61, manufactured by Norland Co., Ltd.), which is an ultraviolet curable adhesive, is dropped on the surface of the thin glass that is not in contact with the surface plate, and the photosensitive layer surfaces of the duplicate hologram are arranged so as to face each other. , Spinner (2000rpm)
An optical adhesive layer having a thickness of 30 μm was formed by a lamination method to obtain a hologram formed body.

Thereafter, the platen and the hologram forming body were taken out of the spinner air chuck as they were, and irradiated with ultraviolet rays (365 nm, 9 J / cm ² ) from the platen side to cure the adhesive. Further, the hologram-formed body was heated in an oven at a temperature of 120 ° C. for 2 hours while the platen was integrated. Finally, when the light was applied to the hologram-formed body from which the surface plate was removed, no shading was observed as in Example 1.

Example 5 100 μm in Example 4
125 µm PET film (T-
When PET (manufactured by Toray Industries, Inc.) was used, as in Examples 2 and 3, slight shading was observed by visual inspection, but there was no effect on reproduction.

[Embodiment 6] 100 μm in Embodiment 4
When a 100 μm silicon wafer was used in place of the thin glass, no shading was observed as in Example 4.

COMPARATIVE EXAMPLE Corning 17 of Example 1
In place of 37, quartz glass manufactured by Matsunami Glass Co., Ltd. (expansion coefficient: 5 × 10 ⁻⁷ / ° C.) and 7622 manufactured by Matsunami Glass Co., Ltd.
When light was applied to the duplicate hologram produced in the combination (expansion coefficient: 120 × 10 ⁻⁷ / ° C.), shading occurred, and the hologram did not function as a hologram former.

Next, using the duplicated hologram-formed bodies obtained in Examples 1 to 6 and Comparative Example, the deformation in the normal direction to the surface at the time of heating and at the time of non-heating was measured. When the presence or absence of shading was inspected, the following evaluation results were obtained. In the following results, in-plane shading indicates the presence or absence of shading of the hologram-formed bodies obtained in Examples and Comparative Examples. Conditions ・ Heating: 100 ° C for 45 minutes ・ Nonheating: 25 ° C ・ Measuring device: Fizeau interferometer ・ Measurement unit: 20 × 30mm ・ Measurement surface: Top surface of hologram photosensitive layer coating

[0030]

As described above, according to the present invention, the difference in the coefficient of thermal expansion between the substrates of the hologram forming body or between the substrates when another substrate is laminated on the thin substrate side is within a predetermined range. This makes it possible to prevent shading from occurring.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a surface plate is fixed to an air chuck.

FIG. 2 is a cross-sectional view showing a state where a substrate is brought into close contact.

FIG. 3 is a view showing a state in which an adhesive is dropped and substrates are stacked.

FIG. 4 is a cross-sectional view showing a state in which substrates are stacked.

FIG. 5 is a cross-sectional view showing a state where a surface plate and a substrate covered with the substrate are brought into close contact with each other and heated.

FIG. 6 is a sectional view of a product obtained by the manufacturing method of the present invention.

FIG. 7 is a diagram illustrating shading of a conventional product.

[Explanation of symbols]

1 ... air chuck, 2 ... platen, 3 ... substrate, 4 ... adhesive,
5: substrate, 6: volume hologram layer, 7: water-soluble resin layer protective film, 8: hologram formed body.

Claims (13)

[Claims] 1. A hologram exposure in which a first substrate, a hologram light-sensitive material layer, and a second substrate are sequentially laminated before or after a second substrate laminating step of a hologram laminate, and then heat development is performed. Wherein the absolute value of the difference between the expansion coefficients of the first substrate and the second substrate is in the range of 100 × 10 ⁻⁷ / ° C. or less. Method. 2. The hologram-forming body according to claim 1, wherein in the hologram laminate, at least one or more intermediate layers other than the hologram light-sensitive material layer are further laminated between the first substrate and the second substrate. Manufacturing method. 3. A third substrate is further laminated on a surface of the second substrate on which another layer is not formed, and expansion of the first substrate and the laminated second and third substrates is performed. 3. The method according to claim 1, wherein the absolute value of the difference between the coefficients is in a range of 100 × 10 ⁻⁷ / ° C. or less. 4. The method according to claim 3, wherein the adhesion strength between the second substrate and the third substrate is in a range of 10 to 10,000 g / cm. 5. The method for producing a hologram-formed body according to claim 1, wherein the in-plane deformation of the first substrate and the second substrate during the heat development is in a range of 0 to 1 mm. 6. The in-plane deformation of the sum of the first substrate, the second substrate, and the third substrate during heat development is 0 to 1 m, respectively.
5. The method for producing a hologram-formed body according to claim 3, wherein m is in the range of m. 7. The method according to claim 3, wherein the third substrate is a surface plate used in a manufacturing process. 8. The method according to claim 1, wherein the substrate is a combination of at least one of glass, plastic and ceramic, and at least one substrate of the hologram forming body is light-transmissive. The method for producing a hologram-formed body according to claim 1. 9. A hologram sensitive material layer wherein a binder resin selected from at least polyvinyl acetate, cellulose acetate butyrate, methyl methacrylate copolymer, polymethyl methacrylate and polyvinyl butyrate is added to 2-phenoxyethyl acrylate and p-chlorophenyl acrylate. , N-vinylcarbazole, at least a monomer selected from N-phenylmaleimide,
The method for producing a hologram-formed body according to any one of claims 1 to 6, comprising a composition of an initiator, a sensitizing dye, a chain transfer agent, and a plasticizer. 10. The method according to claim 2, wherein the intermediate layer includes an adhesive layer. 11. The condition of heat development is a temperature of 100 to 20.
The method for producing a hologram-formed body according to claim 1, wherein the heating time is in the range of 0 ° C and the heating time is in the range of 0.5 to 5 hours. 12. The hologram according to claim 3, wherein the relationship among the areas S1, S2, and S3 of the first substrate, the second substrate, and the third substrate is S1, S2> S3. A method for producing a formed body. 13. The method according to claim 3, wherein the height difference Δx between the surfaces of the second substrate and the third substrate is 1 μm or less.