JPH0643797A - Formation of hologram - Google Patents

Abstract

PURPOSE:To form the hologram which has high diffraction efficiency and is free from variations in diffraction efficiency and reproduced wavelength by development conditions by inserting a polymn. component different from the polymn. component of a recording carrier into the unpolymerized regions in the dark parts of interference fringes and forming a hologram image by the difference in the refractive index therebetween. CONSTITUTION:The recording carrier consisting of a matrix polymer and a photopolymerizable compd. (host monomer) and further, a photopolymn. initiator is exposed to interference patterns of light and is then immersed into a developer contg. a photo- or thermopolymerizable compd. (host monomer). The recording carrier is then cured by heat or light, by which the hologram is formed. This development stage is so executed as to induce a swelling or contrating effect in accordance with the hologram patterns and to elute the unreacted photosensitive component in unexposed parts, to substitute the host monomer in the unexposed parts with the guest monomer or to add the guest monomer to the host monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hologram forming method,
In particular, it relates to a volume phase hologram forming method.

[0002]

2. Description of the Related Art Holography is a technique for recording interference fringes generated on a recording medium by using a light source having good coherence such as a laser. Photoresist as the recording material,
Although dichromated gelatin, silver halide emulsion, etc. are known, all of them have problems in resolution, cost, moisture resistance, etc., and it is the current situation that a high-quality volume phase hologram has not yet been obtained. .

A hologram recording material comprising poly-N-vinylcarbazole, a polyfunctional monomer and a photopolymerization initiator is known as a recording material (Japanese Patent Laid-Open No. 2-21).
No. 6180, No. 2-216181), the swelling step and the shrinking step are performed at the time of development, but the hologram reproducibility depends largely on the temperature and humidity at that time, and the same reproduction wavelength and diffraction efficiency should be maintained. However, it was difficult to avoid the occurrence of the whitening phenomenon due to the rapid film shrinkage because the crosslink density of the polymer was low at low exposure energy.

[0004]

SUMMARY OF THE INVENTION The present invention firstly provides a hologram forming method which has a high diffraction efficiency and is free from variations in diffraction efficiency and reproduction wavelength due to developing conditions.

Secondly, there is provided a method of forming a hologram without a whitening phenomenon.

Thirdly, there is provided a hologram forming method capable of controlling the reproduction color.

[0007]

In the hologram forming method of the present invention, a record carrier comprising a matrix polymer, a photopolymerizable compound (hereinafter referred to as a host monomer), and a photopolymerization initiator is exposed to a light interference pattern. After that, the record carrier is immersed in a developing solution containing a compound capable of photopolymerization (hereinafter referred to as guest monomer), and then the record carrier is cured by heat or light. The components constituting the record carrier in 1) will be described.

As the matrix polymer, polymethacrylic acid ester or its partial hydrolyzate, polyvinyl acetate or its hydrolyzate, polystyrene, polyvinyl butyral, polychloroprene, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, poly -N-vinylcarbazole or a derivative thereof, poly-N-vinylpyrrolidone or a derivative thereof, a copolymer of styrene and maleic anhydride or a half ester thereof, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, acrylamide, acrylic A copolymer having a monomer selected from a group of copolymerizable monomers such as nitrile as a polymerization component is used.

Particularly preferred is poly-N-vinylcarbazole or a derivative thereof, such as poly-N-vinylcarbazole, vinylcarbazole-styrene copolymer, vinylcarbazole-vinyl chloride copolymer, vinylcarbazole-methylmethacrylate. Copolymer, vinylcarbazole-vinylanthracene copolymer, vinylcarbazole-vinylpyridine copolymer, vinylcarbazole-acrylate copolymer, vinylcarbazole-
Ethyl acrylate copolymer, vinylcarbazole-acrylonitrile copolymer, vinylcarbazole-butylacrylate copolymer, vinylcarbazole-nitrovinylcarbazole copolymer, nitrated poly-N-vinylcarbazole, polyvinylaminocarbazole, vinylcarbazole-N -Methylaminovinylcarbazole copolymer, halogen-substituted poly-N-vinylcarbazole,
Examples thereof include vinylcarbazole-dibromovinylcarbazole copolymer, polyiodovinylcarbazole, polybenzylidenevinylcarbazole, and polypropenylcarbazole. By using these poly-N-vinylcarbazoles as a matrix polymer, it is possible to obtain a hologram having good moisture resistance. Also, poly-N
-Vinylpyrrolidone or a derivative thereof is also preferable, and examples thereof include copolymers of poly-N-vinylpyrrolidone and vinyl acetate, glycidyl methacrylate, alkyl (meth) acrylate, styrene and the like.

Next, the photopolymerizable compound (host monomer) having an ethylenically unsaturated bond will be described.

As the host monomer, photopolymerization having at least one ethylenically unsaturated double bond in one molecule,
Photocrosslinkable monomers, oligomers, prepolymers and mixtures thereof, examples of monomers and copolymers thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds. , Amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds, and the like.

Specific examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and their halogen-substituted unsaturated carboxylic acids such as chlorinated unsaturated carboxylic acids. Examples thereof include brominated unsaturated carboxylic acid and fluorinated unsaturated carboxylic acid. Examples of the salts of unsaturated carboxylic acids include sodium salts and potassium salts of the above-mentioned acids.

Specific examples of the monomer of the ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate and 1,3-butanediol diacrylate. Acrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4 -Cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol Lutriacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri ( Acryloyloxyethyl) isocyanurate, polyester acrylate oligomer and the like.

Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis- [p- (3 -Methacryloxy-2- Mud propoxy) phenyl] dimethyl methane, bis - [p- (acryloxy ethoxy phenyl] dimethyl methane, 2,2-bis (4-methacryloyloxy) propane, methacrylate -2
-There is naphthyl, etc.

As itaconic acid esters, ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,
4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like can be mentioned.

As the crotonic acid ester, ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Examples thereof include sorbitol tetracrotonate.

Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate and sorbitol tetramaleate.

As the halogenated unsaturated carboxylic acid,
2,2,3,3-tetrafluoropropyl acrylate, 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 1H, 1H, 2H, 2H-heptadeca Fluorodecyl methacrylate, methacrylic acid-
2,4,6-Tribromophenyl, dibromoneopentyl dimethacrylate (trade name: NK ester DBN, manufactured by Shin Nakamura Chemical Co., Ltd.), dibromopropyl acrylate (trade name: NK ester A-DBP, Shin Nakamura Chemical Co., Ltd.) Co., Ltd.), dipromopropyl methacrylate (trade name: NK ester DBP, Shin Nakamura Chemical Co., Ltd.),
Methacrylic acid chloride, methacrylic acid-2,4,6-
Trichlorophenyl, p-chlorostyrene, methyl-2
-Chloroacrylate, ethyl-2-chloroacrylate, n-butyl-2-chloroacrylate, methacrylic acid-2,4,6-trichlorophenyl, tribromophenol acrylate, tetrabromophenol acrylate and the like.

Specific examples of the amide monomer of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound include methylenebisacrylamide, methylenebismethacrylamide, 1,6-hexamethylenebisacrylamide, 1,
6-hexamethylene bis methacrylamide, diethylene triamine tris acrylamide, xylylene bis acrylamide, xylylene bis methacrylamide, N-phenyl methacrylamide, diacetone acrylamide, etc. are mentioned.

[0021] As another example, Japanese Patent Publication No. 48-417
No. 08, the polyisocyanate compound having two or more isocyanate groups in one molecule, the following general formula CH ₂ ═C (R) COOCH ₂ CH (R ′) OH (wherein R and R ′ are hydrogen or And a vinyl urethane compound having two or more polymerizable vinyl groups in one molecule, to which a vinyl monomer having a hydroxyl group represented by a methyl group) is added.

Further, urethane acrylates described in JP-A-51-37193, JP-A-48-641
83, Japanese Patent Publication No. 49-43191, Japanese Patent Publication No. 5
Polyester acrylates, epoxy resins and (meth) as described in JP 2-30490 A, respectively.
Mention may be made of polyfunctional acrylates and methacrylates such as acrylic acid.

Furthermore, the magazine of Japan Adhesive Association Vol. 20, N
O7, those introduced as photocurable monomers and oligomers on pages 300 to 308 can also be used.

In addition, as the monomer containing phosphorus, mono (2-acryloyloxyethyl) acid phosphate (trade name: light ester PA, manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.), mono (2-methacryloyloxyethyl) Acid phosphate (trade name: Light Ester PM, manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), and epoxy acrylate type trade name: Lipoxy VR-60 (Showa Highpolymer Co., Ltd.), trade name: Lipoxy VR-90 (manufactured by Showa Highpolymer Co., Ltd.) and the like can be mentioned.

Trade name: NK ester M-230G
(Manufactured by Shin-Nakamura Chemical Co., Ltd.), trade name: NK ester 2
3G (manufactured by Shin-Nakamura Chemical Co., Ltd.) is also included.

Further, triacrylates having the following structural formula,

[0027]

[Chemical 1]

(Toagosei Chemical Industry Co., Ltd., trade name, Aronix M-315)

[0029]

[Chemical 2]

(Trade name, Aronix M-325, manufactured by Toagosei Kagaku Kogyo Co., Ltd.), and 2,2'-bis (4-
Acryloxy-diethoxyphenyl) propane (Shin-Nakamura Chemical Co., Ltd., trade name, NK ester A-BPE-4), tetramethylolmethane tetraacrylate (Shin-Nakamura Chemical)
(Trade name, NK ester A-TMMT) manufactured by K.K.

These host monomers are used in an amount of 0.1 to 3 parts by weight, preferably 0.3 to 1.5 parts by weight, based on 1 part by weight of the matrix polymer.

Next, the photopolymerization initiator / sensitizer includes 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 2-dimethylaminobenzoate, ethyl 2-dimethylaminobenzoate and 4-dimethyl. Ethyl aminobenzoate, butyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2,2-diethoxyacetophenone, benzyldimethylketal, benzyl-β-methoxyethylacetal. , 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, benzophenone, methyl o-benzoylbenzoate,
Michler's ketone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, dibenzoyl (1,2-diphenylethanedione), benzoin (2-phenyl-2-hydroxy-acetophenone), benzoin methyl ether, benzoin ethyl ether , Benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin butyl ether (n and iso 50: 5
0 mixture), benzoin alkyl ether, 4'-isopropyl-2-hydroxy-2-methyl-propiophenone, 2-hydroxy-2-methyl-propiophenone, p-dimethylaminoacetophenone, pt-butyltrichloroacetophenone. , P-t-butyldichloroacetophenone, p-azidobenzaldehyde, p-azidoacetophenone, p-azidobenzoic acid, p-azidobenzalacetophenone, p-azidobenzalacetone, 4,4′-diazidochalcone, 1, 3-bis-
(4'-azidobenzal) -acetone, 2,6-bis-
(4'-azidobenzal) -cyclohexanone, 2,6
-Bis- (4'-azicytobenzal) -4-methylcyclohexanone, 4,4'-diazidostilbene-2,
2'-disulfonic acid, 1,3-bis- (4'-azidobenzal) -2-propanone-2'sulfonic acid, 1,3-
Bis- (4'-azidobenzal) -2-propanone-
2,2'-sodium disulfonate, 1,3-bis-
(4'-Azidocinnaylidene) -2-propanone, azidopyrene, 3-sulfonylazidobenzoic acid, 4-sulfonylazidobenzoic acid, 2,6-bis- (4'-azidobenzal) -cyclohexanone-2 ', 2disulfone Acid (sodium salt), 2,6-bis- (4'-azidobenzal) -methyl-cyclohexanone 2,2'-disulfonic acid (sodium salt), 4-diazodiphenylamine sulfate, 4-diazo-4'-methoxy- Diphenylamine sulfate, 4-diazo-3-methoxy-diphenylamine, sodium salt of naphthoquinone (1,2) diazide (2) -4-sulfonic acid, sodium salt of naphthoquinone (1,2) diazide (2) -5-sulfonic acid Salt, naphthoquinone (1,2) diazide (2) -5-sulfonic acid ester (1), naphthoquinone (1, ) Diazide (2) -5-
Sulfonic acid ester, naphthoquinone (1,2) diazide (2) -5-sulfonic acid ester (3) -novolac resin ester, diazo resin (sulfate and zinc chloride double salt of diazodiphenylamine / paraformaldehyde condensate, etc.), tri Phenylpyrylium perchlorate, 4-methoxyphenyl-2,6-diphenylpyrylium perchlorate, 4-butoxyphenyl-2,6-diphenylpyrylium perchlorate, triphenylthiopyrylium perchlorate Salt, 4-methoxyphenyl-2,6-diphenylthiopyrylium perchlorate, thioxanthone, 2-methylthioxanthone (2-methyl-9H-thioxanthene-9-
On), chlorothioxanthone (2-chloro-9H-thioxanthene-9-one), 2-isopropylthioxanthone (2-isopropyl-9H-thioxanthene-9).
-On), dibenzosuberone, 2,5-bis- (4'-
Diethylaminobenzal) cyclopentanone, 1-acetylamino-4-nitronaphthalene, 5-nitroacenaphthene, 1-nitropyrene, α, α-dichloro-4-phenoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, or trade name : Kayakyu MBP (manufactured by Nippon Kayaku Co., Ltd.), trade name: UVECRYL P36
(UCB) and the like can be used, and these can be used alone or in combination.

Further, a coumarin compound represented by the following general formula (1) and an organic peroxide may be mentioned.

[0034]

[Chemical 3]

(In the formula, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a chlorine atom, a lower alkoxy group, a lower dialkylamino group, a lower dialkenylamino group or an alicyclic amino group. Has a total of 5 carbon and heteroatoms
~ 9 heterocyclic groups or -COY groups are represented. Here, Y is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a lower alkoxy group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted steryl group, or a substituted or unsubstituted 3'-coumarino group. Represent Z represents a hydrogen atom or a cyano group. In the formula, R ₁ , R ₂ and R ₃ are preferably hydrogen atoms, chloro atoms, lower alkoxy groups such as methoxy, ethoxy and butoxy, lower dialkylamino such as dimethylamino, diethylamino and N-methyl-N-propylamino. Base, N
Examples thereof include alicyclic amino groups such as -morpholino and N-piperidino, and lower dialkenylamino groups such as dipropenylamino and di (α-methylpropenyl) amino groups.

The heterocyclic group in X is 2-imidazole, 2-N-methylimidazole, 2-benzimidazole, 2- (4-phenyl) -imidazole, 2-oxazole, 2-benzoxazole, 2- (4- Phenyl) oxazole, 2-thiazole, 2-benzthiazole, 2- (4-phenyl) thiazole, 2- (5-
Phenyl) thiadiazole, 2- (5-tolyl) thiadiazole, 2- (5-biphenyl) thiadiazole, 2
-(5-phenyl) oxadiazole, 2- (5-p-
Methoxyphenyl) oxadiazole, 2- (5-p-
Examples thereof include residues such as chlorophenyl) oxadiazole.

As Y in the --COY group, methyl, ethyl, propyl, hexyl, β-cyanoethyl,
A substituted or unsubstituted C ₁ -C ₆ alkyl group such as ethoxycarbonylmethyl, butoxycarbonylmethyl, phenyl, p-cyanophenyl, p-methylphenyl, p-
A substituted or unsubstituted phenyl group such as methoxyphenyl and m-hydroxycarbonylphenyl, a steryl group such as steryl, p-methoxysteryl, p-cyanosteryl, and m-chlorsteryl, and a 3-coumarino group represented by the following general formula:

[0038]

[Chemical 4]

(Wherein R ₁ , R ₂ , R ₃ and Z are the same as those in the above formula (1)) and the like.

Specific examples of the coumarin compound include 3-acetyl-7-dimethylaminocoumarin and 3-benzoyl-
7-dimethyl-aminocoumarin, 3-benzoyl-5,
7-dimethoxycoumarin, methyl, 7-diethylamino-3-coumarinoyl acetate, 3-cinnamoyl-7
-Diethylaminocoumarin, 3,3'-carbonylbis (7-diethylamino) coumarin, 3,3'-carbonylbis (5,7-dimethoxyamino) coumarin, 7-diethylamino-5,7'-dimethoxy-3,3 ' -Biscoumarin, 3- (2'-benzimidazoyl) -7-diethylaminocoumarin, 3- (2'-benzoxazoyl) -7-diethylaminocoumarin, 3- (5'-phenylthiadiazoyl-2 ') Examples thereof include -7-diethylaminocoumarin, 3- (2'-benzthiazoyl) -7-diethylaminocoumarin, and 3,3'-carbonylbis (4-cyano-7-diethylamino) coumarin. .

Preferred compounds of the organic peroxide used as a mixture with the coumarin compound include methyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, t-butyl peroxide, cumene hydroperoxide and diisopropylbenzene. Peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α′-bis (t-
Butyl cumyl peroxyisopropyl) benzene, t-
Butyl peroxy isopropyl carbonate, benzoyl peroxide, di (t-butyl peroxy) isophthalate, di (t-butyl peroxy) terephthalate, di (t-butyl peroxy) phthalate, t-butyl peroxybenzoate, 3, 3 ', 4,4'-tetra- (t-butylperoxycarbonyl) benzophenone, 2,5-dimethyl-2,5- (dibenzoylperoxy) hexane and the like are used.

Of these, particularly preferred are di (t-butylperoxy) isophthalate, di (t-butylperoxy) terephthalate, di (t-butylperoxy) phthalate, 3,3 ', 4. 4'-tetra-
(T-butylperoxycarbonyl) benzophenone may be mentioned.

The proportion of the organic peroxide added to the coumarin compound is 1 part by weight to 1 part by weight of the coumarin compound.
It is 100 parts by weight, preferably 1 part by weight to 50 parts by weight.

These photopolymerization initiators are 1 to 80 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the total amount of the above-mentioned matrix polymer and host monomer.
Used in parts by weight.

Further, a composition for forming a record carrier is prepared by adding a thermal polymerization inhibitor, a plasticizer and the like in addition to the above composition.

The record carrier in the present invention comprises the above composition, for example, benzene, chlorobenzene, tetrahydrofuran, 1,4-dioxane, 1,2-dichloroethane,
Dissolve in dichloromethane, chloroform, etc., glass,
It is coated on a support such as a transparent resin film. The coating method is spinner coating, blade coating, roll coating, etc., and the film thickness after drying is 0.5.
It is applied to a thickness of μm to 50 μm. The support itself of the matrix polymer itself may be used to form a film by itself.

The record carrier thus obtained is sensitive to a laser beam having a bright line at, for example, 4579Å, 4880Å, 5145Å, 5287Å, etc., for example, 1 for an argon laser having a wavelength of 4880Å.
Energy of up to 500 mJ / cm ² gives diffraction efficiency in a practical range.

Next, the hologram forming method of the present invention will be described.

The hologram forming method of the present invention comprises a step of exposing the record carrier to radiation, a developing step using a developing solution containing a guest monomer, and a step of photo-curing or heat curing the record carrier after development.

Radiation rays that can be used in the step of exposing the recording unit to radiation rays are preferably radiation rays using a laser beam, a mercury lamp, or the like as a light source.

When forming a hologram, a Lippmann hologram forming apparatus for forming a volume phase hologram by irradiating an object with two coherent bundles of radiation at a predetermined offset angle as shown in FIG. 1, or
A Deniseuk-type hologram forming apparatus that forms a volume phase hologram by the interference between the irradiation light and the reflected light from the subject as shown in FIG. 2 is used.

Next, the developing step is carried out by immersing the record carrier on which the hologram latent image is formed in a developing solution containing a guest monomer.

This developing step is a feature of the present invention. The swelling or shrinking action is caused on the record carrier according to the formed hologram pattern, and the unreacted photosensitive component in the unexposed area is eluted. At the same time, a developing solution containing a guest monomer is permeated into the unexposed area to replace the host monomer in the unexposed area with the guest monomer or to add the guest monomer to the host monomer.

The solvent in the developer has a function of causing swelling or contraction of the crosslinked polymer produced by the photopolymerization reaction of the photosensitive component in a short time and eluting unreacted photosensitive component. Examples of the swelling liquid include benzene, toluene, xylene, ethylbenzene, n-propylbenzene, cumene, phenol, cresol, chlorobenzene, dichlorobenzene, nitrobenzene, benzyl alcohol, benzyl chloride, benzyl bromide, α-methylnaphthalene, Examples thereof include derivatives of benzene and naphthalene such as α-chlornaphthalene, and a mixed solvent thereof may be used. The contraction liquid is a solvent that does not dissolve or swell the recording material, and includes, for example, n-pentane, n-hexane, n.
-Alkanes such as heptane, n-octane, isooctane and cyclohexane, cycloalkanes, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, n-amyl alcohol, isoamyl alcohol, etc. Alcohols, ethers such as diethyl ether, methyl ethyl ether and diisopropyl ether, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, methyl acetate, ethyl formate and methyl propionate are used. A mixed solvent may be used.

In the present invention, it is necessary to allow the guest monomer to enter between the interference fringes, and it is preferable to use a solvent having a swelling action.

The interval of the interference fringes can be controlled by appropriately selecting the solvent in the developing solution.

Next, the photo- or heat-polymerizable compound (guest monomer) in the developing solution will be described.

First, as the guest monomer that can be photo- or heat-polymerized, those described as the host monomer are used, and the same compound as the host monomer may be used, but the photo-refraction between the guest monomer and the host monomer is different. By using a monomer having a difference in refractive index, it is possible to obtain a high diffraction efficiency when it is made into a hologram, and it is possible to obtain a hologram having a higher diffraction efficiency as the difference in the optical refractive index is larger.

The guest monomer is preferably liquid at 25 ° C. to 100 ° C., soluble in the solvent in the developing solution, and has a high molecular weight (viscosity). Furthermore, if the molecular weight of the guest monomer is too low, it flows out from the unexposed portion in the hologram preparation stage, and as a result, the refractive index difference required for the hologram cannot be obtained, and the obtained hologram tends to gradually disappear.

The developing step is carried out by directly immersing the record carrier in the developing solution. First, the photosensitive component in the unexposed portion of the recording carrier is removed by using only the solvent, and then the developing solution is immersed in the developing solution. May be. The concentration of the guest monomer in the developing solution is appropriately set, but it is preferably at least 1% by weight or more.

The record carrier thus developed is then subjected to a curing step.

In the curing step, the guest carrier in the unexposed area is cured and the record carrier is fixed by irradiating the record carrier with light such as ultraviolet rays or by heating.

The surface of the obtained hologram may be left as it is, or glass, a plastic film or the like may be stuck.

[0064]

The volume phase hologram using a photopolymer largely depends on the composition of the record carrier and the developing method, but in the conventional production of this kind of hologram, the developing step was swollen, Reproducibility is difficult to obtain because it requires two steps of shrinkage, and the white turbidity phenomenon due to film shrinkage and drying steps is an unavoidable problem. It was discovered that a polymerization component different from the polymerization component is inserted and a hologram image is formed by the difference in the refractive index.

The volume phase hologram has the property of reflecting and reproducing only specific light, and its wavelength depends on the interval of the interference fringes recorded in the hologram layer.
According to the hologram forming method of the present invention, by developing with a developing solution containing a photocurable or thermosetting polymer component and then curing the record carrier, the interval of the interference fringes is fixed without changing due to swelling and contraction. This makes it possible to manufacture a hologram having a uniform reproduction wavelength with good reproducibility, and it is possible to control the reproduction wavelength by selecting a solvent and a combination of a host monomer and a guest monomer. Further, it can be regarded as a transparent hologram which does not cause any whitening phenomenon due to cracks or the like generated when shrinking a conventional swelled record carrier.

Further, by making the photorefractive index of the polymerized component in the record carrier, that is, the host monomer and the polymerized component in the developing solution, that is, the guest monomer different from each other, it is possible to obtain a high diffraction efficiency and obtain a high brightness. It can be a high hologram.

According to the present invention, a hologram having a controlled reproduction wavelength and a high diffractive index can be produced with good reproducibility, so that the hologram can be used for, for example, a light control device.

The present invention will be described below with reference to examples.

[0069]

Example 1 The following composition: Poly-N-vinylcarbazole {manufactured by Anan Sangyo Co., Ltd., Tubicor No. 210 (trade name) average molecular weight 400,000 to 500,000} ... 1.0 g tribromophenol methacrylate [Daiichi Kogyo Seiyaku Co., Ltd., trade name BR-31] ・ ・ ・ 0.5 g ・ 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone ・ ・ ・ 0.08 g・ 3,3'-Carbonylbis (7-diethylaminocoumarin) ... A composition having 0.003 g was dissolved in 10 g of 1,4-dioxane,
A sensitizing solution was obtained after 0.25 μm filtration.

This photosensitive solution was applied onto a glass plate having a thickness of 3 mm using an applicator so that the film thickness after drying was 9 μm, and dried at 70 ° C. for 45 minutes, and then polyvinyl alcohol (manufactured by Kuraray Co., Ltd.). Polymerization degree 500 Saponification degree 88
%) 10% aqueous solution with a spin coater at 2000 rpm
It was applied by spin coating. This was dried at 60 ° C. for 10 minutes to obtain a record carrier.

Next, the Lippmann diffraction grating photographing optical system shown in FIG. 1 was used to expose the hologram with light having a wavelength of 488 nm by an argon laser. Exposure was performed with a light intensity ratio of 1: 1 and an exposure energy of 20 mJ / cm ² . After exposure with an argon laser, a chemical lamp (Toshiba Corp.)
FL-20BL) was used for full exposure for 60 seconds. At this time, a sharp cut filter L39 was used to irradiate only visible light of 400 nm or more. After exposure, put the record carrier in running water 1
After washing with water for 1 minute to remove the polyvinyl alcohol layer and drying, the record carrier was immersed in a 10 wt% acetone solution (developing solution) of trimethylolpropane acrylate for 3 minutes.

Then, the record carrier is taken out of the developer,
It was irradiated with a xenon lamp and cured to produce a Denishuk type hologram.

In the above examples, the guest monomers shown in the following table were used in place of the trimethylolpropane acrylate as the guest monomer, and Denisyuk holograms were produced. In the table below, the difference in optical refractive index between the guest monomer and the host monomer and the maximum diffraction efficiency of the obtained hologram are shown in the table below.

[0074]

[Table 1]

The products represented by the above-mentioned trade name: ACTYCRYL are all manufactured by SMP in France, ACTYCRYL CL959
Is the structural formula

[0076]

[Chemical 5]

ACTYCRYL CL960 is represented by the following structural formula

[0078]

[Chemical 6]

ACTYCRYL CL993 is represented by the following structural formula

[0080]

[Chemical 7]

ACTYCRYL CL1039 is represented by the following structural formula:

[0082]

[Chemical 8]

It is shown by.

Further, in the above-mentioned example, the hologram was prepared 10 times under the same conditions on the record carrier using tribromophenol methacrylate as the guest monomer, and the reproducibility was observed. The maximum diffraction efficiency was ± 10.
%, The reproduction wavelength (λ _max ) fluctuated only by ± 10%.

Further, with respect to the hologram using peptadecafluoropropyl acrylate as a guest monomer in the above-mentioned record carrier, the record carrier was exposed to light having a wavelength of 488 nm by an argon laser by a Deniseuk type hologram forming apparatus shown in FIG. did. The exposure energy is 20 mJ / cm ² . The diffraction grating obtained by the same treatment as above had a maximum diffraction efficiency of 50% or more, and a hologram similar to that of the Lippmann type was obtained.

The relationship between the refractive index difference in the above table and its maximum diffraction efficiency is shown in FIG. From the above table and FIG. 3, etc., it is possible to obtain a higher diffraction efficiency as the difference in the refractive index between the guest monomer and the host monomer is larger, and it is possible to change the reproduction wavelength by combining the guest monomer and the host monomer. Recognize.

[0087]

Comparative Example 1 The record carrier in the above example is immersed in toluene as a developing solution for 3 minutes to remove tourist components, dried and further immersed in a mixed solvent of toluene: xylene = 1: 1 for 1 minute. Swollen.

Next, when the hologram was prepared by immersing it in n-peptane for 1 minute to shrink it, and then forcibly drying it with a dryer to create a hologram, a whitening phenomenon occurred, and a hologram was prepared 10 times under the same conditions and reproduced. As a result, the maximum diffraction efficiency fluctuated between 0% and 80%, and the reproduction wavelength (λ _max ) fluctuated between 400 nm and 800 nm, and there was a problem in reproducibility.

[0089]

[Example 2] The product name ACT, which is a urethane acrylate monomer as the guest monomer in Example 1 above
Using YCRYL CL960, manufactured by SMP, France, and using the host monomers shown in the table below, a record carrier was prepared in the same manner as in Example 1 and developed in the same manner as in Example 1 to prepare a Lippmann hologram. The evaluation as a hologram is shown in the table below at the same time. The sensitivity of this hologram was as high as 5 mJ / cm ² .

[0090]

[Table 2]

From the above table, it can be seen that the reproduction wavelength changes depending on the host monomer.

[0092]

Example 3 In the above Example 1, triacrylate (Aronix manufactured by Toagosei Co., Ltd.) was used as the host monomer.
M-315 (trade name)} is used in the same manner, and a guest carrier shown in the table below is used to prepare a record carrier in the same manner as in Example 1, and development is performed in the same manner as in Example 1 to produce a Lippmann hologram. did. The evaluation as a hologram is shown in the table below at the same time.

[0093]

[Table 3]

(Incidentally, the guest monomers having the above trade names are the same as those used in Example 1.) From the above table, the use of guest monomers having a large difference in photorefractive index improves the diffraction efficiency. You can see that you can.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a Lippmann hologram forming apparatus.

FIG. 2 is a schematic diagram of a Deniseuk type hologram forming apparatus.

FIG. 3 is a diagram showing the relationship between the difference in optical refractive index between the host monomer and the guest monomer and the maximum diffraction efficiency of the hologram produced according to the present invention.

[Simple explanation of symbols]

In the figure, 1 is an argon laser, 2 is a half mirror, 3 is a mirror, 4 is a spatial filter, 5 is a photosensitive plate, and 6 is a subject.

Claims (2)

[Claims] 1. A development, which comprises exposing a record carrier comprising a matrix polymer, a photopolymerizable compound, and a photopolymerization initiator to an interference pattern of light, and then exposing the record carrier to a photopolymerizable or thermopolymerizable compound. A method for forming a hologram, which comprises immersing in a liquid and then curing the record carrier by heat or light. 2. The hologram according to claim 1, wherein the photorefractive index of the photopolymerizable compound in the record carrier is different from the photorefractive index of the photopolymerizable or thermopolymerizable compound in the developer. Forming method.