JP3126395B2 - Method for manufacturing hologram recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram recording photoreceptor capable of suitably recording a volume phase hologram and a method for manufacturing the photoreceptor.

[0002]

2. Description of the Related Art Conventionally, an amplitude type, a phase type (refractive index modulation type) and a surface type and a volume type based on the recording principle, and a transmission type (opposite direction) from the direction of illumination light and diffracted light at the time of reproduction. Holograms classified into reflection type (in the same direction) and the like are known. Among them, the volume phase type is the most excellent particularly in optical characteristics such as diffraction efficiency, and it has been proved that the maximum diffraction efficiency obtained is theoretically 100% for both the transmission type and the reflection type. Therefore, volume phase holograms are not only display holograms that record images, but also gratings that use high diffraction efficiency,
Applications as various optical elements such as optical demultiplexing, light condensing, and laser beam scanning elements are also considered.

[0003] As a volume phase type hologram material, a photographic light-sensitive material such as a silver salt emulsion or dichromated gelatin (D
CG) has been used. Silver salt materials are widely used because of their high sensitivity and DCG because of their excellent optical properties such as diffraction efficiency, but they also have the disadvantage that complicated wet processing is indispensable. Is the current situation.

In recent years, so-called photopolymers have been attracting attention and developed as volume phase hologram materials in place of silver salts and DCG. Photopolymers can be classified into types that require wet processing after interference exposure and types that require or omit dry processing. Examples of the former include JP-A-60-502125 and JP-A-2-88.
8, 2-2168180 and the like. Examples of the latter are described in JP-A-2-3081, 2-3082, 2-
51188 and the like. In this case, the photopolymerizable monomer is contained in the recording material, and the polymerization of the photopolymerizable monomer proceeds selectively according to the light intensity distribution formed by the interference fringe exposure, and the interference fringes are recorded according to the composition distribution. Is done.

[0005]

The above-mentioned conventional photopolymer uses a solid polymer soluble in a solvent as one component of the composition, is dissolved in the solvent and mixed with other components, and the solution is used as a substrate. Need to be applied to the surface. That is, once all components including the polymer component are dissolved and mixed in a solvent,
Thereafter, the composition is coated on a substrate such as a glass plate or a plastic film, and the solvent is volatilized and dried to produce a hologram recording composition. That is, the conventional photopolymer is applied on a smooth surface such as a glass plate or a resin film by using various coating methods to provide a photosensitive material as a photosensitive layer / substrate laminate.

Therefore, in order to actually use a hologram recorded on a conventional photopolymer as, for example, an optical element, the layer on which the hologram is recorded must be strongly adhered to the substrate. It is necessary to provide a special adhesive layer between the substrate and the photosensitive layer, add an additive to increase the adhesive strength, or re-stack the recorded hologram on another substrate. did.

An object of the present invention is to provide a hologram recording apparatus in which a photosensitive layer is formed inside a surface layer of a plastic substrate itself without requiring a process for increasing the adhesive force between the hologram recording layer and the substrate as in the prior art. It is an object of the present invention to provide a photosensitive member for use, a method for manufacturing the same, and a method for manufacturing a hologram recording body.

[0008]

That is, the present invention provides a polymer film or sheet having a polymerizable carbon-carbon double bond in a transparent plastic film or sheet made of a resin having a three-dimensional crosslinked structure , and Contacting a photopolymerizable composition containing a monomer or oligomer capable of producing a polymer having a refractive index different from the refractive index of the plastic film or sheet by at least 0.02 to form a surface layer of the plastic film or sheet. a first step of forming a photosensitive layer by impregnating the photopolymerizable composition therein, the photosensitive layer, a second step of exposure light on the interference fringes obtained by radiation having a coherence, require According to the second
Following the step, the photopolymerizable set of the photosensitive layer after the interference fringe exposure
Weight of unpolymerized oligomers and monomers remaining in the product
Production of a hologram recording body consisting of a third step to complete the integration
Is the way .

Hereinafter, the present invention will be described in detail. The photopolymerizable composition used in the present invention has at least one carbon-carbon double bond in the molecule, and has a refractive index of at least 0.0
1, preferably a monomer or oligomer capable of producing a polymer having a refractive index difference of 0.02 or more, for example, a carbon-carbon double bond such as an acryloyl group, a methacryloyl group, a vinyl group, or an allyl group in a molecule. And a monomer or oligomer containing one or more polymerizable groups, which can be photopolymerized by adding an appropriate photoinitiator.

As a specific example of the above-mentioned monomer, those having at least one acryloyl group, methacryloyl group, vinyl group or allyl group in the molecule are preferable. For example, methyl acrylate, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyloxyethyl acrylate, isobornyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ω-
Hydroxyhexanoyloxyethyl acrylate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate, phenyl acrylate, tribromophenyl acrylate, phenoxyethyl acrylate, tribromophenoxyethyl acrylate, tribromophenoxy polyethylene glycol acrylate, benzyl acrylate, p-bromobenzyl Acrylates, 2-ethylhexyl acrylate, lauryl acrylate, 2,2,3,3-tetrafluoropropyl acrylate and methacrylates corresponding to these monofunctional acrylates, bisphenol A diacrylate, 2,2-bis (4 Polyacrylic acid such as -acryloxyethoxy-3,5-dibromophenyl) propane or Methacrylates corresponding to these acrylates - DOO acids, or vinyl benzoate, styrene, p- chlorostyrene, divinylbenzene, vinyl acetate, acrylonitrile, N- vinylpyrrolidone,
Vinyl compounds such as vinyl naphthalene, or diethylene glycol bisallyl carbonate, dialylidene pentaerythritol, triallyl isocyanurate,
Allyl compounds such as diallyl phthalate and diallyl isophthalate are exemplified.

Examples of the oligomer include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, polyacrylate having an isocyanuric acid skeleton, melamine acrylate, polyacrylate having a hydantoin skeleton, polybutadiene acrylate, and the like.
Epoxy acrylate, urethane acrylate and the like can be mentioned.

These monomers or oligomers can be used alone, but a mixture of these monomers or oligomers or a mixture of these monomers or oligomers and a solvent can also be used. Examples of the solvent include toluene, n-hexane, cyclohexane methyl alcohol,
Examples include organic chemicals such as ethyl alcohol, acetone, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, dimethylformamide, dimethylacetamide, and acetonitrile. The solvent helps the above-mentioned monomer or oligomer to penetrate inside the surface layer of the plastic film or sheet.

The photoinitiator to be added to the photopolymerizable composition used in the present invention generates a chemical species having polymerization activity, for example, a radical by irradiation with coherent light used for recording a hologram. The photopolymerization initiator comprises a photopolymerization initiator and a photosensitizer for extending the photosensitive wavelength range of the photopolymerization initiator.
If the photopolymerization initiator has sufficient sensitivity to the wavelength of the light for hologram recording, no photosensitizer is required.

The photopolymerization initiator of the present invention includes the following compounds. For example, 2,3-bornanedione (camphorquinone), 2,2,5,5-tetramethyl
Cyclic cis-α- such as tetrahydro-3,4-furanic acid
Dicarbonyl compound, benzophenone, diacetyl, benzyl, Michler's ketone, diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone,
Ketones such as -hydroxycyclohexylphenyl ketone; peroxides such as benzoyl peroxide and di-t-butyl peroxide; azo compounds such as allyldiazonium salt; aromatic carboxylic acids such as N-phenylglycine; 2-chlorothioxanthone , Xanthenes such as 2,4-diethylthioxanthone, diallyliodonium salts, triallylsulfonium salts, triphenylalkylborates, iron allene complexes, bisimidazoles, polyhalogen compounds, phenylisoxazolone, benzoin ethyl ether, benzyldimethyl ketal (Including a mixture). Further, examples of the auxiliary include amines, thiols, p-toluenesulfonic acid and the like.

The concentration of the photopolymerization initiator varies depending on the type of the photopolymerizable composition, but is usually added in an amount of 0.1 to 10 parts by weight based on the photopolymerizable composition.

Furthermore, examples of the photosensitizer that may be used in the present invention include the following compounds, but are not limited thereto. For example, compounds having an absorption band in the visible light region (including a mixture) such as methylene blue, acridine orange, thioflavin, ketocoumarin dyes, erythrosine C, eosin Y, merocyanine, phthalocyanine, porphyrin and the like.

The concentration of the photosensitizer also varies depending on the type of the photopolymerizable composition.
1 to 5 parts by weight are added.

[0018] As the plastic film or sheet used in the present invention, those having transparency (colorless or colored), in which the monomer, oligomer monomer or melted to the solvent, the oligomer can penetrate
In addition , a resin having a three- dimensional crosslinked structure is used. As the resin having a three- dimensional cross-linked structure, for example, at least one of the above monomers or oligomers is a polyfunctional resin.
A film or a sheet obtained by polymerizing the composition containing the kinds is exemplified. Further, these mixtures and copolymers are also included. If necessary, a stabilizer or a light absorber is added to these plastic films or sheets.
These plastic films or sheets Ru can suitably used in a thickness of 0.05 to 10 mm.

As an example of the combination of the monomer or oligomer used in the present invention and a plastic film or sheet, polymethyl methacrylate (refractive index: 1.49)
0) and benzyl acrylate (polymer having a refractive index of 1.55)
8), polyvinyl butyral (refractive index: 1.490) and phenoxyethyl acrylate (polymer refractive index: 1.55)
7) can be mentioned.

In the present invention, a method of contacting the plastic film or sheet with the photopolymerizable composition maintained in a liquid or gaseous state, or applying the photopolymerizable composition to the plastic film or sheet, etc. To form a swollen photosensitive layer by infiltrating a monomer or oligomer into the surface layer of the plastic film or sheet. At this time, it is possible to accelerate the formation of the photosensitive layer by bringing the monomer or oligomer into contact with the surface of the plastic film or sheet while applying pressure, such as contacting with heating or contacting in a high-pressure atmosphere. it can. The thickness of the photosensitive layer is at least 1 to 100 μm, preferably 5 to 100 μm.
接触 30 μm, and the contact time is usually 1 minute to 1 hour. At this time, the gel layer is in a state where the photopolymerizable composition has entered the gap between the polymers of the resin constituting the plastic film or sheet.

Thereafter, a resin film or a glass plate transparent to the coherent radiation to be exposed in the next step is covered on the surface of the obtained hologram recording film by an appropriate method. This is because the polymerization proceeds by radical polymerization of the present composition, so as to prevent polymerization inhibition by oxygen upon exposure to coherent radiation, and to prevent adhesion of dust and foreign matter. . If the exposure is performed under an inert gas, the polymerization is not inhibited by oxygen, so that the cover may be omitted.

Next, the above-mentioned photoreceptor for hologram recording is exposed to interference fringes obtained by coherent radiation. In this step, a known method using a laser light source as a coherent light source is generally used. As an interference exposure method, for example, an optical system as shown in FIG. 1 can be used. Usually, this method is called a two-beam interference exposure method. In the case of the exposure optical system shown in FIG. 1, a laser beam from a laser oscillator 1 passes through a shutter 2 and is collimated by a beam expander 3 and a collimator lens 4. Further, the light is split into two by a beam splitter 5 and is incident on the hologram recording material 7 at a constant angle θ on the recording material via total reflection mirrors 6 and 6 ′. On the recording surface, interference fringes having a constant spatial frequency (fringe interval) are formed by the angles of these two light beams, so that the interference fringes are recorded on the recording material.

When recording an object, the object is irradiated with one of the two light beams and the reflected light (in this case, referred to as object light)
Then, interference fringes due to the other light beam (in this case, referred to as reference light) are recorded in the recording material. When the recording material is held so that both light beams are irradiated from the same direction (in the case of FIG. 1), the transmission hologram is recorded, and the recording material is held so that the light is irradiated from the opposite direction. In this case (FIG. 2), a reflection hologram is recorded. The irradiation time of the coherent radiation for exposing the interference fringes varies depending on the intensity of the radiation, the recording area and the like, but is usually 1 second to 30 minutes, and the total exposure amount is 1 to 5000 mJ / cm ^2. Exposure so that

The mechanism by which the hologram is formed is probably as follows. For example, a photosensitive layer (gel layer) formed by infiltrating a monomer or oligomer B (polymer B ′ obtained by polymerizing it with a high refractive index) into the surface of a plastic film or sheet made of polymer A (having a low refractive index) ) Is exposed to interference fringes obtained by coherent radiation, a light intensity distribution corresponding to the interference fringes is formed inside the gel layer, and polymerization of the monomer or oligomer B starts from a portion having a high light intensity. ,
The monomer or oligomer B in the low light intensity portion diffuses and moves to the high light intensity portion, and the concentration of the polymer B ′ in the high light intensity portion increases. Accordingly, the structure of the polymer A originally existing partially moves or shifts from a portion having a high light intensity to a portion having a low light intensity. as a result,
At the time when the polymerization is completed, the concentration of the polymer B 'is high in the portion having a high light intensity (the concentration of the polymer A is low), and conversely, the concentration of the polymer A is high in the portion having a low light intensity (the concentration of the polymer B' is low). )Become. Since the polymer B 'has a higher refractive index than the polymer A, the surface of the plastic film or sheet has a portion having a high refractive index (a portion having a high light intensity) and a portion having a low refractive index (a portion having a low light intensity). Are formed, which can be confirmed by an optical microscope.

In the present invention, a hologram can be recorded only by the first step of exposing the photosensitive member for hologram recording to interference fringes obtained by coherent radiation. However, subsequent to the first step, the polymerization of the unpolymerized monomer or oligomer remaining in the hologram recording material in the first step is completed, and the unreacted photopolymerization initiator and the photosensitizer such as a dye are increased. It is preferable to go through the second step of deactivating the sensitizer. This step can be carried out by irradiating the hologram composition after interference exposure with uniform light having a wavelength capable of polymerizing or reacting.
This uniform light irradiation promotes the polymerization of the unpolymerized monomer or oligomer in the hologram material, and the interference fringes recorded in the first step are completely fixed. Further, by the second step, the photopolymerization initiator and the photosensitizer can be made inactive, whereby the durability of the recording film, that is,
Heat resistance and moisture resistance are also improved. The light irradiation in the second step is performed so that the total exposure amount is usually about 10 to 10,000 mJ / cm ² .

[0026]

Ri by the present invention, by using a resin having a three-dimensional crosslinking, at the same time capable of forming a hologram recording photosensitive material, without the need for a conventional such laminate, the plastic substrate or film it has become possible to produce a hologram Symbol Rokutai with hologram Symbol Rokuso the surface layer.

[0027]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Description of Compounds Shown Below> BTTB:

Embedded image KCD:

Embedded image UA:

Embedded image Example 1 t-based on 100 parts by weight of methyl methacrylate monomer
A composition containing 1.2 parts by weight of butyl peroxypivalate, 0.6 parts by weight of t-butyl peroxyisopropyl carbonate, and 2.5 parts by weight of nonaethylene glycol diacrylate was polymerized by thermal polymerization to obtain a particle having a size of 20.
A transparent polymethyl methacrylate sheet (refractive index: 1.490) having a size of 20 mm × 20 mm and a thickness of 3 mm was prepared.

One side of this sheet was treated with 100 parts by weight of a benzyl acrylate monomer (polymer having a refractive index of 1.55).
8) A photosensitive layer having a tackiness of about 15 μm having a thickness of about 15 μm by immersing in a mixed solution of 5 parts by weight of BTTB and 0.1 part by weight of KCD for 10 minutes at an ambient temperature of 50 ° C. to swell the sheet surface. I got Size 20mm x 20mm,
A 100 μm-thick polyethylene terephthalate cover film was placed on the photosensitive layer and allowed to adhere to obtain a photosensitive member.

Using the two-beam interference exposure method as shown in FIG. 1, the photosensitive member 7 (the photosensitive layer is perpendicular to the paper surface) is used to radiate 514.5 nm light oscillated from the argon ion laser 1 into the shutter 2 and the shutter 2. The beam expander 3 and the collimator lens 4 convert the light into parallel light, and the light split by the beam splitter 5 is incident on the recording material at an incident angle θ = 5 °.
And made incident on the photoreceptor. Exposure was performed so that the total exposure amount was about 500 mJ / cm ^2, and the light completed polymerization of the photosensitive layer, and a bright transmission type diffraction grating was obtained.

Example 2 3 g of polyvinyl butyral was dissolved in 12 g of dioxane, and a transparent polyvinyl butyral film (refractive index: 1.490) of about 200 μm was obtained by casting.
One side of this film was treated with 100 parts by weight of phenoxyethyl acrylate monomer (polymer refractive index 1.55).
7) Contacted with a mixed solution of 5 parts by weight of BTTB and 0.1 part by weight of KCD at an ambient temperature of 50 ° C. for 10 minutes to swell to obtain a gel-like photosensitive layer having a thickness of about 20 μm on the surface. A 100 μm-thick polyethylene terephthalate cover film was adhered onto the photosensitive layer to obtain a photosensitive member.

Using a two-beam interference exposure method as shown in FIG. 2, the photosensitive member 17 (the photosensitive layer is perpendicular to the plane of the paper) is used to apply 514.5 nm light oscillated from an argon ion laser 11 to a shutter 12. The light was collimated by the beam expander 13 and the collimator lens 14, and the light split by the beam splitter 15 was incident on the recording material 17 at an incident angle θ = 30 °. Total exposure is about 3
Exposure was performed so as to be 00 mJ / cm ^2, and a bright reflective diffraction grating was obtained.

Example 3 Polyether urethane acrylate (UA; refractive index of polymer: 1.493) obtained by reaction of polypropylene glycol having an average molecular weight of 1,000 with toluene diisocyanate and 2-hydroxyethyl acrylate 10
A composition in which 3 parts by weight of hydroxyisobutylphenone is added to 0 parts by weight is 10 cm × 10 cm and has a thickness of 2 mm.
Was applied to a thickness of about 500 μm on a transparent glass plate, and polymerized by irradiation with a high-pressure mercury lamp to obtain a transparent film having a thickness of about 500 μm. The glass plate with the film attached thereto is treated with benzyl acrylate monomer 1
00 parts by weight (polymer refractive index 1.558), BTTB
The film was immersed in a bath of a mixed solution of 5 parts by weight and 0.1 part by weight of KCD at an ambient temperature of 20 ° C. for 30 minutes to swell the outer surface of the film attached to the glass plate, thereby forming a gel-like photosensitive layer of about 16 μm. Obtained. A 100 μm-thick polyethylene terephthalate cover film was adhered onto the photosensitive layer to obtain a photosensitive member.

In the same manner as in Example 1, the above photoreceptor was exposed by ^two- beam interference so that the total exposure amount was about 300 mJ / cm ^2, and a bright transmission type diffraction grating was obtained.

[Brief description of the drawings]

FIG. 1 shows an exposure optical system for producing a transmission diffraction grating.

FIG. 2 shows an exposure optical system for producing a reflection type diffraction grating.

[Explanation of symbols]

 1, 11, Argon ion laser 2, 12, Shutter 3, 13, Beam expander 4, 14, Collimator lens 5, 15, Beam splitter 6, 16, Total reflection mirror 7, 17, Photoreceptor for hologram recording

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoshi Ishizuka 3-5-1, Doshomachi, Chuo-ku, Osaka City Inside Nihonita Glass Co., Ltd. (72) Toshifumi Tsujino 3-5-1, Doshomachi, Chuo-ku, Osaka-shi No. Nihon Sheet Glass Co., Ltd. (72) Inventor Naoto Hirayama 3-5-1, Doshomachi, Chuo-ku, Osaka-shi Nihon Sheet Glass Co., Ltd. (56) References JP-A-61-165784 (JP, A) 53-15152 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03H 1/00-5/00

Claims (3)

(57) [Claims] 1. A resin body which is transparent and has a three-dimensional crosslinked structure
The Ranaru plastic film or sheet, a polymerizable carbon - carbon double bond, and a monomer or oligomer capable of producing a polymer wherein the plastic film or sheet refractive index of at least 0.02 refractive index different A first step of forming a photosensitive layer by contacting a photopolymerizable composition containing the photopolymerizable composition into the surface layer of the plastic film or sheet to form a photosensitive layer; a second step of exposure light on the interference fringes obtained by radiation having a coherence needs
Accordingly, following the second step, the sensitivity after the exposure of the interference fringes is adjusted.
Unpolymerized oligomer remaining in the photopolymerizable composition of the optical layer
And holography <br/> method for manufacturing a ram recording body comprising a third step to complete the polymerization of the monomers. Wherein said third step, the feeling after interference fringe exposure
To the optical layer, the unpolymerized oligomers and monomers heavy <br/> case or reaction rows uniform light irradiation by a wavelength can Umo is <br/> of claim 1 hologram recording material according Production method. Wherein the third step, the feeling after interference fringe exposure
For light layer, the manufacturing method according to claim 1 hologram recording material according to heat treatment of at least 60 ° C. is the row of Umo <br/>.