JPH08101627A - Photosensitive composition for volumetric hologram recording, recording medium formed by using the same, and formation of volumetric hologram - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a photosensitive composition which has a high refractive index modulation and gives a volume hologram excellent in light resistance, and a volume hologram recording method using the same. In a photosensitive composition for volume hologram recording used for recording interference fringes produced by interference of laser light or light having excellent coherence as fringes having different refractive indices, the composition comprises a) a glycidyl group-containing compound having a residual chlorine content of 1% by weight or less, (b) a radically polymerizable compound, (c) the component (b) is polymerized by being exposed to the above-mentioned laser light or light having excellent coherence. A photosensitive composition for volume hologram recording, comprising each component of a photo-radical polymerization initiator system and (d) a cationic polymerization initiator system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition for recording a volume hologram, a recording medium using the same and a method for recording a volume hologram. More specifically, the present invention is
TECHNICAL FIELD The present invention relates to a photosensitive composition for volume hologram recording which gives a hologram having excellent refractive index modulation and light resistance, and a volume hologram recording method capable of easily producing a hologram using the same.

[0002]

2. Description of the Related Art A hologram is one in which two light beams having the same wavelength (object light and reference light) are made to interfere with each other and the wavefront of the object light is recorded as an interference fringe on a photosensitive material. When this light is applied, a diffraction phenomenon due to interference fringes occurs, and the same wavefront as the original object light can be reproduced.

Holograms are classified into several types according to the recording pattern of interference fringes. In recent years, so-called volume holograms, which record interference fringes by the difference in refractive index inside the recording layer, have high diffraction efficiency and excellent wavelength selection. Due to its properties, it is being applied to applications such as three-dimensional displays and optical elements.

As a material for recording such a volume hologram, a material using silver halide or dichromated gelatin which has been conventionally used in the art field is generally used. However, these are not suitable for industrial production of holograms because they require wet development and complicated development and fixing processing, and have a problem that the image disappears due to moisture absorption after recording. .

In order to solve these problems, it is known that a volume hologram can be produced by using a photopolymer only by a simple dry process. US Pat. Nos. 3,658,526 and 3,993,485. It has been proposed in. In addition, regarding the presumed formation mechanism of the hologram by the photopolymer, "Applied OPTICS"
(BL Booth, Volume 14, No3, P
P593-601 (1975) and W.P. J. Tomlinson
(W. J. Tomlinson), E.I. A. Chandross (EA
Chandross), Vol. 15, No. 2, PP534-54
1 (1976). However, in these techniques, the most important performance of the hologram, that is, the refractive index modulation, did not reach the above-mentioned conventional techniques.

In recent years, as a photopolymer material excellent in refractive index modulation, a photopolymer material described in JP-A-5-107999, in which a radical polymerizable compound having a different refractive index and a cation polymerizable compound are used in combination, has been proposed. There is. When this material is used, a volume hologram having a relatively large refractive index modulation can be obtained by a dry process, but a volume hologram having light resistance that can withstand outdoor use is desired.

[0007]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a photosensitive composition which provides a volume hologram having high refractive index modulation and excellent light resistance, and a volume hologram recording method using the same. To aim.

[0008]

That is, the present invention relates to a photosensitive composition for volume hologram recording used for recording interference fringes produced by interference of laser light or light having excellent coherence as fringes having different refractive indexes. In the composition, the composition comprises (a) a glycidyl group-containing compound having a residual chlorine content of 1% by weight or less, (b) a radically polymerizable compound, (c) the above laser beam or light having excellent coherence. A photoradical polymerization initiator system that polymerizes the component (b) upon exposure to light, and
(d) A photosensitive composition for volume hologram recording, comprising each component of a cationic polymerization initiator system.

The present invention also provides a recording medium and a volume hologram recording method using the above composition. The invention further provides a hologram obtained using the above composition.

When a glycidyl group-containing compound is used as a cationically polymerizable compound in a photopolymer material for hologram recording in which a radically polymerizable compound and a cationically polymerizable compound are used in combination, the glycidyl group-containing compound is
It is usually synthesized using a chlorine-containing epoxy compound such as epichlorohydrin in a two-step reaction consisting of an addition reaction step of epichlorohydrin and a glycidylation step by alkali ring closure as follows:

First reaction (addition step of epichlorohydrin):

Embedded image

Second reaction (alkali ring closure step):

Embedded image

In the formula, R mainly represents an alkyl group or an aryl group. Further, as the catalyst, for example, caustic soda, sodium carbonate, tertiary amines and the like can be used.

In the conventional synthesis method described above, the glycidyl group-containing compound (II) containing chlorine as a side reaction product is produced together with the desired glycidyl group-containing compound (I).
The presence of this compound (II) causes problems such as a decrease in diffraction efficiency and yellowing of the hologram itself when the hologram is exposed to light such as sunlight.

Therefore, in the present invention, the residual chlorine content relative to the total amount of the glycidyl group-containing compound is set to 1% by weight or less, whereby a photosensitive composition having a high refractive index modulation and a volume hologram excellent in light resistance is obtained. Found that we can provide

The light resistance is improved because the C—Cl bond, which is easily cleaved by ultraviolet rays contained in sunlight, is substantially eliminated, and the deterioration reaction due to radical species generated from the photocleavage of the bond is suppressed. it is conceivable that.

In the present specification, "residual chlorine" means not only chlorine atoms present in the above-mentioned side reaction product (II) but all chlorine atoms present in the glycidyl group-containing compound.

The glycidyl group-containing compound (a) having a residual chlorine content of 1% by weight or less used in the present invention is obtained by reacting an alcohol with sodium hydroxide to form a sodium alkoxide, which is condensed with epichlorohydrin. It can be synthesized by a reaction. This reaction can be represented by the following reaction formula.

[0019]

Embedded image

In the formula, R mainly represents an alkyl group or an aryl group.

In this reaction, since the epichlorohydrin is directly condensed without the addition reaction of epichlorohydrin in the one-step reaction, the chlorine content becomes low.

Specific examples of the glycidyl group-containing compound (a) having a residual chlorine content of 1% by weight or less include a glycidyl group obtained by a condensation reaction between sodium alkoxide of ethylene oxide adduct of pentaerythritol and epichlorohydrin. Compound containing, glycidyl group-containing compound obtained by condensation reaction of sodium alkoxide of propylene oxide adduct of pentaerythritol with epichlorohydrin, compound obtained by condensation reaction of sodium alkoxide of propylene oxide adduct of glycerin with epichlorohydrin Examples thereof include, but are not limited to, a glycidyl group-containing compound, a glycidyl group-containing compound obtained by a condensation reaction of sodium alkoxide of an ethylene oxide adduct of sorbitol, and epichlorohydrin.

Radical polymerizable compound used in the present invention
It is preferable that (b) has at least one ethylenically unsaturated double bond in the molecule. The average refractive index of the radically polymerizable compound (b) is the glycidyl group-containing compound (a)
It is preferably larger than that. When the average refractive index of the compound (b) is lower than that of the compound (a), the refractive index modulation is insufficient, which is not preferable.

Specific examples of the radically polymerizable compound (b) include acrylamide, methacrylamide, styrene, 2-bromostyrene, phenyl acrylate and 2-
Phenoxyethyl acrylate, 2,3-naphthalenedicarboxylic acid (acryloxyethyl) monoester, methylphenoxyethyl acrylate, nonylphenoxyethyl acrylate, β-acryloxyethyl hydrogen phthalate, phenoxypolyethylene glycol acrylate, 2,4,6-tribromo Phenyl acrylate,
Diphenic acid (2-methacryloxyethyl) monoester,
Benzyl acrylate, 2,3-dibromopropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-naphthyl acrylate, N-vinylcarbazole, 2- (9-carbazolyl) ethyl acrylate, triphenylmethylthioacrylate, 2- ( tricyclo [5,2,10 ^2.6] dibromo decyl thio) ethyl acrylate, S- (1-naphthylmethyl) thio-acrylate, dicyclopentanyl acrylate, methylenebisacrylamide, polyethylene glycol diacrylate, trimethylol propane triacrylate, Pentaerythritol triacrylate, diphenic acid (2-acryloxyethyl) (3-acryloxypropyl-2-hydroxy) diester, 2,3-naphthalene dicarboxylic acid
(2-acryloxyethyl) (3-acryloxypropyl-2-hydroxy) diester, 4,5-phenanthrene dicarboxylic acid (2-acryloxyethyl) (3-acryloxypropyl-2-hydroxy) diester, dibromneo Pentyl glycol diacrylate, dipentaerythritol hexaacrylate, 1,3-bis [2-acryloxy-3- (2,4,6-tribromophenoxy) propoxy] benzene, diethylenedithioglycol diacrylate, 2,2-bis ( 4-acryloxyethoxyphenyl) propane, bis (4-acryloxydiethoxyphenyl) methane, bis (4-acryloxyethoxy-3,5
-Dipromophenyl) methane, 2,2-bis (4-acryloxyethoxyphenyl) propane, 2,2-bis (4-
Acryloxydiethoxyphenyl) propane, 2,2-bis (4-acryloxyethoxy-3,5-dibromophenyl) propane, bis (4-acryloxyethoxyphenyl) sulfone, bis (4-acryloxydiethoxyphenyl) Sulfone, bis (4-acryloxypropoxyphenyl) sulfone, bis (4-acryloxyethoxy-3,5
-Dibromophenyl) sulfone, and compounds in which the above-mentioned acrylate is changed to methacrylate, and further, at least two S atoms are contained in the molecule as described in JP-A-2-247205 and JP-A-2-261808. The above-mentioned compounds containing an ethylenically unsaturated double bond are included, and one or more of them may be used.

The radically polymerizable compound (b) of the present invention also has a 9,9-diarylfluorene skeleton, is liquid at room temperature, and has at least one ethylenically unsaturated double bond in the molecule. May be When this is used, high refractive index modulation is easily obtained. The radically polymerizable compound which has a 9,9-diarylfluorene skeleton and is liquid at room temperature is represented by the formula:

[0026]

[Chemical 4]

R ₁ , R ₂ : at least one of the terminals has a radically polymerizable group such as an acryloyl group or a methacryloyl group, and this group and the benzene ring have at least one oxyethylene chain, oxypropylene chain, It is bonded via a urethane bond or an amide bond.

Specific examples of X _{1 to} X ₄ are: H, alkyl group (C ₁ to X ₄
C _4), an alkoxy group (C ₁ ~C _4), an amino group, a dialkylamino group, a hydroxyl group, a carboxyl group, represented by a halogen group.

Among these, those in which an acryloyl group or a methacryloyl group in R ₁ and R ₂ is bonded to a benzene ring via an oxyethylene chain or an oxypropylene chain is particularly preferable. Specific examples of these are 9,9
-Bis (4-acryloxydiethoxyphenyl) fluorene, 9,9-bis (4-acryloxytriethoxyphenyl) fluorene, 9,9-bis (4-acryloxytetraethoxyphenyl) fluorene, 9,9-bis (4-acryloxydipropoxyphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3-methylphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3)
-Ethylphenyl) fluorene, 9,9-bis (4-acryloxydiethoxy-3-ethylphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3,5-
Examples include dimethyl) fluorene and compounds in which the above “acryloxy” is changed to “methacryloxy”.

Photoradical polymerization initiator system used in the present invention
(c) is an initiator that produces active radicals by the first exposure for hologram production, and the active radicals polymerize the radically polymerizable compound (b), which is one of the constituents of the present invention. Any system will do. Examples of such a radical photopolymerization initiator system (c) include, for example, US Pat.
No. 66,055, No. 4,868,092, No. 4,96
5,171, JP-A-54-151024, and JP-A-5-151024.
No. 8-15,503, No. 58-29,803,
59-189,340, 60-76735, JP-A-1-28715, and Japanese Patent Application No. 3-556.
No. 9 and "Proceedings of Conference on Radiation Curing Asia"
(PROCEEDINGS OF CONFERENC
E ON RADIATION CURING ASI
A) "(P.461-477, 1988) and the like, but known initiator systems can be used.

In the present specification, the term "initiator system" means that a sensitizer, which is a component that generally absorbs light, and an active radical generating compound or an acid generating compound can be used in combination. As the sensitizer in the photo-radical polymerization initiator system, a colored compound such as a dye is often used in order to absorb visible laser light, but when the final hologram is required to be colorless and transparent (for example, in an automobile, (When used as a head-up display of the above), as a sensitizer, JP-A-58-29803, JP-A 1-2
It is preferable to use cyanine dyes as described in Japanese Patent Application No. 87105 and Japanese Patent Application No. 3-5569.

Since the cyanine dyes are generally easily decomposed by light, the dyes in the hologram are decomposed to be in the visible region by post-exposure in the present invention, or by leaving them under room light or sunlight for several hours to several days. A colorless and transparent hologram is obtained without absorption. Specific examples of the cyanine dye include anhydro-3,3′-dicarboxymethyl-
9-ethyl-2,2'thiacarbocyanine betaine, anhydro-3-carboxymethyl-3 ', 9-diethyl-
2,2'thiacarbocyanine betaine, 3,3 ', 9-triethyl-2,2'-thiacarboxyanine iodine salt,
3,9-Diethyl-3'-carboxymethyl-2,2'-thiacarbocyanine iodine salt, 3,3 ', 9-triethyl-2,2'-(4,5,4 ', 5'-dibenzo ) Thiacarbocyanine iodine salt, 2- [3- (3-ethyl-2-benzothiazolidene) -1-propenyl] -6- [2- (3-ethyl-2-benzothiazolidene) ethylideneimino ] -3-Ethyl-1,3,5-thiadiazolium iodine salt, 2-
[[3-allyl-4-oxo-5- (3-n-propyl-
5,6-Dimethyl-2-benzothiazolilidene) -ethylidene-2-thiazolinylidene] methyl] 3-ethyl-4,
5-diphenylthiazolinium iodine salt, 1,1 ', 3,
3,3 ', 3'-hexamethyl-2,2'-indotricarbocyanine-iodine salt, 3,3'-diethyl-2,2'-thiatricarbocyanine perchlorate, anhydro-1-ethyl -4-Methoxy-3'-carboxymethyl-5'-chloro-2,2'-quinothiacyanine betaine, anhydro-5,5'-diphenyl-9-ethyl-3,3'-disulfopropyloxacarbocyanine Hydroxide triethylamine salt, 2- [3- (3-ethyl-2-benzothiazolidene) -1-propenyl] -6- [2- (3-ethyl-2)
-Benzothiazolidene) ethylideneimino] -3-ethyl-1,3,5-thiadiazolium iodine salt,
One or more of these may be used.

As the active radical generating compound which may be used in combination with the cyanine dye, the above-mentioned JP-A-58 is used.
-29803, JP-A-1-287105,
Diaryl iodonium salts as described in Japanese Patent Application No. 3-5569, or 2,4,6-substituted-1,3,
Examples include 5-triazines. The use of diaryliodonium salts is particularly preferred when high photosensitivity is required. Specific examples of the diaryliodonium salts include diphenyliodonium, 4,4′-dichlorodiphenyliodonium, 4,4′-dimethoxydiphenyliodonium, 4,4′-ditert-butyldiphenyliodonium and 3,3′-dinitrodiphenyliodonium. Chloride, bromide, tetrafluoroborate, etc.
Hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate, trifluoromethanesulfonate, etc. are exemplified. Specific examples of 2,4,6-substituted-1,3,5-triazines include 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,5. -Tris (trichloromethyl) -1,3,
5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (p-methoxyphenylvinyl)-
1,3,5-triazine, 2- (4'-methoxy-1'-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-
Examples include triazine and the like.

Cationic polymerization initiator system used in the present invention
(d) is capable of initiating a cationically polymerizable compound by generating an initiating species such as Bronsted acid or Lewis acid by the action of light or heat. The photocationic polymerization initiator system used in the present invention has a low photosensitivity to the first exposure and generates a Bronsted acid or a Lewis acid upon exposure to light having another wavelength, and these are the above-mentioned glycidyl groups. Group-containing compound
Any initiator system that polymerizes (a) may be used. In the present invention, during polymerization of the radically polymerizable compound by irradiation with laser light or light having excellent coherence, it is preferable that the cationically polymerizable compound in a liquid state at room temperature is present in a state in which almost no reaction is caused, which is more than the conventional technique. It is believed that a large index modulation is obtained. Therefore,
It is particularly preferable that the cationic photopolymerization initiator system does not polymerize the cationically polymerizable compound during the first exposure.

Examples of the cationic photopolymerization initiator system include "UV curing; science and technology (UV CURING: SCIEN).
CE AND TECHNOLOGY) "(pp.23-7)
6, S. Peter Purpose (S. PETER PAP
PAS) editing, a technology marketing
Publication (A TECHNOLOGY MAR
KETING PUBLICATION]] and "Comments Inorg. Che.
m. ) "(B. Klingert, M. Leediker and A.
Rolov (B.Klingert, M.RIEDIKER
and A. ROLOFF), Volume 7, No. 3, pp10
9-138 (1988)] and the like, and one or more of them may be used.

Particularly preferred cationic photopolymerization initiator systems used in the present invention include diaryl iodonium salts, triaryl sulfonium salts, iron allene complexes and the like.

Preferred diaryl iodonium salts as the cationic photopolymerization initiator system are iodonium tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimodium as shown in the photoradical polymerization initiator (c). And trifluoromethane sulfonate, 9,10-dimethoxyanthracene sulfonate and the like.
Preferred triarylsulfonium salts are triphenylsulfonium, 4-tert-butyltriphenylsulfonium, tris (4-methylphenyl) sulfonium, tris (4-methoxyphenyl) sulfonium, 4-thiophenyltriphenylsulfonium and the like. Examples include sulfonium tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate, trifluoromethanesulfonate, 9,10-dimethoxyanthracene-2-sulfonate, and the like.

In the photosensitive composition of the present invention, if necessary, a polymer binder, a thermal polymerization inhibitor, a silane coupling agent,
You may use a coloring agent etc. together. The polymer binder is used to improve the film-forming property and film thickness uniformity of the composition before hologram formation, and to post-expose the interference fringes formed by polymerization by irradiation with laser light or light with excellent coherence. Until
Used for stable presence. The polymeric binder is
Any compound having good compatibility with the cationically polymerizable compound or the radically polymerizable composition may be used, and specific examples thereof include chlorinated polyethylene, polymethylmethacrylate, copolymers of methylmethacrylate and other (meth) acrylic acid alkyl ester. , A copolymer of vinyl chloride and acrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, ethyl cellulose, acetyl cellulose and the like. The polymer binder may have reactivity such as a cationically polymerizable group in its side chain or main chain.

In the composition of the photosensitive composition of the present invention, the component (a) is contained in an amount of 5-80 wt% (particularly 30-%) based on the total weight of the composition.
60 wt%), component (b) is 10-80 wt% (especially 30-60w)
t%), the radical photopolymerization initiator system (c) is 0.3 to 8 wt% (particularly 1 to 5 wt%), and the cationic polymerization initiator system (d) is 0.
3 to 8 wt% (particularly 1 to 5 wt%) is preferable.

The photosensitive composition of the present invention may be prepared by a conventional method. For example, the above-mentioned essential components (a) to (d) and optional components as they are or as necessary a solvent (e.g., methyl ethyl ketone, methyl isobutyl ketone, acetone,
Ketone solvents such as cyclohexanone, ethyl acetate, butyl acetate, ester solvents such as ethylene glycol diacetate, aromatic solvents such as toluene and xylene,
Cellosolve solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methanol, ethanol,
Propanol, alcohol solvent such as n-butanol, tetrahydrofuran, ether solvent such as dioxane, halogen solvent such as dichloromethane, dichloroethane, chloroform) are blended and mixed by using, for example, a high-speed stirrer in a cool dark place. Can be prepared.

In the production of the hologram of the present invention, the recording layer is a transparent support such as a glass plate, a polyethylene terephthalate film, a polyethylene film, an acrylic plate, a triacetyl cellulose film or a polycarbonate plate, which is prepared by using the above-mentioned photosensitive composition by a conventional method. It can be formed by coating on the surface and drying if necessary. The coating amount is appropriately selected. For example, the dry coating amount is 1 g / m ²
It may be ˜50 g / m ² .

Further, usually, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a triacetyl cellulose film, a polycarbonate plate, a glass plate, an acrylic plate or the like is provided as a protective layer on the recording layer for use. As another method for producing a three-layer body in which the intermediate layer is the recording layer of the composition of the present invention, for example, recording is performed between two polyethylene terephthalate films, each of which has been subjected to a treatment for easy peeling. A layer may be formed in advance, and one film may be peeled off at the time of use and the surface thereof may be laminated on an appropriate support. Further, for example, the composition of the present invention can be injected between two glass plates.

The recording layer thus prepared is made of laser light or light having excellent coherence (for example, a wavelength of 300 to 1).
The interference fringes are recorded in the inside by the interference fringes by the usual holographic exposure device of 200 nm). In the case of the composition of the present invention, diffracted light due to the recorded interference fringes can be obtained at this stage to form a hologram. However, at this stage, since the unreacted polymerizable compound remains in the photosensitive layer, the hologram film strength may not be obtained in some cases. Heat treatment is performed to polymerize the unreacted components remaining in these photosensitive layers, or as a post-exposure, light from a xenon lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a halogen lamp, etc. is entirely exposed to the hologram. By doing so, a hologram having excellent film strength can be obtained. It is also possible to change the diffraction efficiency, the peak wavelength of the diffracted light, the half-value width, etc. by treating the recording layer with heat or infrared rays before or after the post-exposure.

The above-mentioned volume hologram is, for example, a lens, a diffraction grating, an interference filter, a head-up display device, a general three-dimensional display, a coupler for optical fibers, an optical polarizer for facsimiles, a memory material for ID cards, etc., for construction. It can be used for window glass, advertising media, etc.

[0045]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Using the photosensitive compositions shown in each of Examples and Comparative Examples described below, a test plate was prepared by the following method, exposed to obtain each hologram, and the physical properties were evaluated by the following methods.

(Preparation of test plate) After dissolving or dispersing a predetermined amount of the photoradical polymerization initiator (system) component (c) and the photocationic polymerization initiator (system) component (d) in the solvent, the component (a), The component (b) and other components such as a polymer binder were added, stirred, and filtered to obtain a photosensitive solution. Apply this sensitizing solution on a 16 cm x 16 cm glass plate using an applicator and
Allow to dry for minutes. Further, a polyethylene film having a thickness of 80 μm (LUPIC LI, Tonen Kagaku KK) was laminated thereon, using a laminating roller, and this plate was divided into 3 to 4 cm squares to obtain test plates.

(Exposure) The first exposure was carried out by using 514.5 nm light of an argon ion laser. FIG. 1 shows a schematic diagram of a recording method of a reflection hologram. The light intensity of one light flux on the surface of the test plate was all 1.0 mW / cm ² , and the exposure was performed for 30 seconds. After the first exposure, as a post-exposure, a high-pressure mercury lamp (manufactured by Nippon Battery Co., Ltd.
The light of L-1001-2) was irradiated from the polyethylene film side for 1 minute.

(Evaluation) The diffraction efficiency of the reflection hologram is
It was determined by measuring the reflectance of the hologram using a self-recording spectrophotometer UV-2100 manufactured by Shimadzu Corporation and an attached integrating sphere reflector ISR-260.

Regarding the light resistance, Dainippon Plastic Co., Ltd.
Super Accelerated Weathering Tester Eye Super UV Tester W
Type holographic test plate with wavelength 295nm
The change of the diffraction efficiency of the hologram test plate, the change of the diffraction peak wavelength, and the yellowing were examined when the ultraviolet rays of ˜450 nm were continuously irradiated for 60 hours.

Yellowing was evaluated by the change in yellowness YI described in JIS-K7103. The yellowness YI was measured by Suga Test Instruments Co., Ltd.
JIS-
It was measured by the transmission measurement method described in K7103.

The photosensitive compositions of the following Examples and Comparative Examples were prepared, and each hologram was prepared by the above method, and evaluated as described above.

(Examples 1 to 3) Here, an example is shown in which a hologram was prepared using a photosensitive composition using a low chlorinated epoxy compound (a) as a cationically polymerizable compound and a light resistance test was conducted. . A-BPHE is used as the radical polymerizable compound, and DYE-1 and DPI are used as the photo radical polymerization initiator system.
A combination of CF ₃ SO ₃ was used. TPS.SbF ₆ was used as the photocationic polymerization initiator system (d).

Table 1 shows the compositions of the hologram recording compositions of Examples 1 to 3 and the evaluation results of the holograms. Table 2 shows the results of the light resistance test of Examples 1 to 3.

[0054]

[Table 1]

[0055]

[Table 2]

In any of the examples, a reflection type hologram was obtained with high refractive index modulation, which showed little change in diffraction efficiency, diffraction peak wavelength and yellowness in the light resistance test.

(Comparative Examples 1 to 3) These are comparative examples to Examples 1 to 3, and when an epoxy compound containing chlorine was used instead of the component (a), the result of the light resistance test was It is an example showing that it is inferior to 1-3.

Table 3 shows the compositions of the photosensitive compositions for hologram recording of Comparative Examples 1 to 3 and the evaluation results of holograms. In addition, Table 4 shows the light resistance test results of Comparative Examples 1 to 3.

[0059]

[Table 3]

[0060]

[Table 4]

The above Examples 1 to 3 and Comparative Examples 1 to
The abbreviations of the compounds described in 3 and Tables 1 to 4 are as follows.

Cationic polymerizable compound (a) CAT-1 ... Glycidyl ether obtained by adding 4 moles of propylene oxide to pentaerythritol Number of glycidyl groups per molecule = about 3 Total chlorine amount = 0.11% by weight, epoxy equivalent = 179 g / e
q CAT-2 ... Glycidyl ether obtained by adding 4 moles of propylene oxide to pentaerythritol Number of glycidyl groups per molecule = about 2.1 Total chlorine amount = 0.17% by weight, epoxy equivalent = 233 g / e
q CAT-3 ... Glycidyl ether obtained by adding 5 mol of propylene oxide to glycerin Number of glycidyl groups per molecule = about 2.3 Total chlorine amount = 0.11% by weight, epoxy equivalent = 225 g / e
q

CAT-1C: pentaerythritol polyglycidyl ether "Nagase Kasei Kogyo, Denacol EX-411" Total chlorine amount = 17% by weight, epoxy equivalent = 231 g / eq ・ CAT-2C ... glycerol polyglycidyl ether "Nagase Kasei, Denacol EX-314" Total chlorine amount = 11.5 wt%, epoxy equivalent = 145 g / e
q CAT-3C ... Sorbitol polyglycidyl ether "Nagase Kasei Kogyo, Denacol EX-614B" Total chlorine amount = 10.5% by weight, epoxy equivalent = 180 g / e
q

Radical polymerizable compound (b) A-BPHE ... 9,9-bis (3-ethyl-4-acryloxydiethoxyphenyl) fluorene

Photoradical polymerization initiator system (c) DYE-1 ... 3,9-diethyl-3'-carboxymethyl-2,2'-thiacarbocyanine, iodine salt-DPI.TF ... diphenyl Iodonium trifluoromethanesulfonate

Photocationic polymerization initiator system (d) TPS SbF ₆ ... Ciba Geigy, triarylsulfonium hexafluoroantimonate compound, trade name UVI-6974

Other Components and Solvents P-1 ... Copolymer of methyl methacrylate / ethyl acrylate / acrylic acid (copolymerization ratio = 45/49 /
6) ・ MIBK ・ ・ ・ Methyl isobutyl ketone ・ BuOH ・ ・ ・ n-Butyl alcohol

[0068]

By using the composition of the present invention, a volume hologram having high refractive index modulation and excellent light resistance can be prepared. Further, the volume hologram prepared by using the composition can sufficiently withstand outdoor use.

[Brief description of drawings]

FIG. 1 shows a schematic view of a reflection hologram recording method in the first exposure.

[Explanation of symbols]

 1: Glass plate 2: Recording layer 3: Polyethylene film 4: Laser 5: Laser beam 6: Mirror 7: Beam splitter 8: Objective lens 9: Lens

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Iwao Sumiyoshi 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Paint Co., Ltd.

Claims (9)

[Claims] 1. A photosensitive composition for volume hologram recording, which is used to record interference fringes produced by interference of laser light or light having excellent coherence as fringes having different refractive indexes, the composition comprising: , (A) a glycidyl group-containing compound having a residual chlorine content of 1% by weight or less, (b) a radically polymerizable compound, (c) the component (b) which is exposed to the above laser beam or light having excellent coherence. A photosensitive composition for volume hologram recording, comprising a photoradical polymerization initiator system to be polymerized and (d) a cationic polymerization initiator system components. 2. A composition according to claim 1, wherein the average refractive index of component (a) is lower than that of component (b). 3. The method according to claim 1, further comprising a polymeric binder.
The composition as described. 4. A volume hologram recording medium having a recording layer of the composition of claim 1 between two transparent supports, which may be the same or different. 5. A volume for exposing the recording medium according to claim 4 to interference fringes generated by the interference of laser light or light having excellent coherence, and subsequently exposing the recording medium to ultraviolet and / or visible light over the entire surface. Hologram recording method. 6. A method for recording a volume hologram, which comprises exposing the recording medium according to claim 4 to interference fringes generated by interference of laser light or light having excellent coherence, and then subjecting the recording medium to heat treatment. 7. The recording medium according to claim 4 is exposed to interference fringes generated by the interference of laser light or light having excellent coherence, and then the entire surface of the recording medium is exposed to light in the ultraviolet and / or visible region. A method for recording a volume hologram in which heat treatment is performed simultaneously or sequentially. 8. The heat treatment is carried out by utilizing the heat generated in the entire surface exposure step of light in the ultraviolet and / or visible region.
Recording method. 9. A volume hologram produced by the recording method according to claim 5.