JPH06274083A - Hologram recording material and production of hologram - Google Patents

Abstract

PURPOSE:To provide the hologram which is usable also as a recording material for HOE having extremely high required performance and has an excellent sensitivity in a visible light region, high resolution and excellent diffraction efficiency, transparency and preservable stability. CONSTITUTION:The hologram recording material consisting of a combination of a polymer having at least >=1 pieces of polymerizable ethylenic unsatd. bonds and >=80000 weight average mol.wt., a compd. having at least >=1 pieces of polymerizable ethylenic unsatd. bonds, a diaryl iodinium salt and a compd. for sensitization capable of absorbing light of any wavelength within a 400 to 550nm wavelength range and sensitizing this diaryl iodinium salt is applied on a substrate and the interference fringe patterns generated by interference of reference light from a visible laser beam source and information light is recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volume phase hologram which is highly sensitive to visible light, especially argon laser light, has good characteristic values such as diffraction efficiency, and is excellent in storage stability. The present invention relates to a recording material and a method of using the recording material.

[0002]

2. Description of the Related Art A hologram reproduces a three-dimensional stereoscopic image and is therefore preferred for its excellent design, and is used for the covers of books, magazines, POP displays, gifts and the like.
In addition, since holograms are equivalent to recording information on the order of submicrons, they are also used to prevent counterfeiting of securities and credit cards. Further, in recent years, in addition to display applications, application to a hologram optical element (HOE) represented by a head-up display mounted on an automobile is expected. The hologram recording material is required to be sensitive to a laser beam having a visible oscillation wavelength with high sensitivity and exhibit high resolution. Also,
In actual use, the hologram diffraction efficiency,
It is required that characteristics such as wavelength reproducibility of reproduction light and band width (half-value width of reproduction light peak) meet the purpose. Specifically, in order to make a recording material for HOE, the diffraction efficiency is 90% or more at a spatial frequency of 5000 to 6000 lines, the half value width (band width) of the peak of the reproduction light is 20 to 30 nm, and the peak of the reproduction wavelength is The wavelength is preferably within 5 nm from the photographing wavelength, and it is also necessary that the storage stability is excellent for a long period of time.

Conventionally, as a hologram material, a bleached silver salt and a dichromated gelatin type photosensitive material have been generally used. However, these hologram recording materials are
All of them have a problem that they require complicated processing after the production and recording of the photosensitive plate and are inferior in environmental resistance characteristics such as humidity resistance and weather resistance.

On the other hand, it has excellent environmental resistance and
A hologram recording material using poly-N-vinylcarbazole can be cited as a material having characteristics that a hologram recording material should have, such as high resolution and high diffraction efficiency. For example, a hologram recording material comprising a cyclic cis-α-dicarbonyl compound as a crosslinking agent and a sensitizer (JP-A-60-45).
No. 283), 1,4,4,5,6,7,7-hexachloro-5-nobornene-anhydrous-2,3-dicarboxylic acid and a hologram recording material comprising a dye (JP-A-60-
No. 227280), a hologram recording material composed of 2,3-bornanedione and thioflavin (Japanese Patent Laid-Open No. Sho 60).
-260080), a hologram composed of thioflavin T and iodoform (Japanese Patent Laid-Open No. 62-123489).
(See Japanese Patent Publication) and the like are proposed. Since these hologram recording materials are photosensitive materials containing poly-N-vinylcarbazole as a main ingredient, they are chemically stable, have high resolution, and are excellent in environmental resistance. However, poly-N-vinylcarbazole is crystallized. It has the problems that it is very likely to whiten, the reproducibility of transparency is poor, and the solvent is limited. Furthermore, further improvement in sensitivity characteristics is desired.

As a material which can be photocured with high sensitivity, a photocurable resin composition which is used in combination with 3-ketocoumarins and a diaryl iodonium salt, which are components of a photopolymerization initiator (see JP-A-60-88005). ), And a hologram recording material in which the photopolymerization initiator is combined with polymethylmethacrylate as a supporting polymer (see JP-A-4-31590). This product is chemically stable and has high resolution and high sensitivity, but because it forms voids by a wet process, it causes variations in the peak wavelength of the reproduction wavelength and expansion of the half-value width of the peak wavelength. At this time, since the supported polymer was slightly dissolved in the swelling solvent, there was a problem that uneven development was likely to occur.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a hologram having excellent chemical stability such as environmental resistance, high resolution, high diffraction efficiency, high transparency, reproduction wavelength reproducibility and developing characteristics even in wet processing. A recording material and a hologram manufacturing method are provided.

[0007]

The present inventor has conducted extensive studies to obtain a recording material having the above various characteristics, and as a result,
The present invention has been completed.

That is, the present invention provides (A) a polymer having at least one polymerizable ethylenically unsaturated bond and having a weight average molecular weight of 80,000 or more, and (B) at least one polymerizable ethylenically unsaturated bond. Having at least one, (C) diaryliodonium salt, and (D) 400
A holographic recording material composed of a combination of sensitizing compounds capable of absorbing any light within a wavelength range of 550 nm to 550 nm and capable of sensitizing a diaryl iodonium salt. The hologram recording material is characterized by recording an interference fringe pattern generated by the interference between the reference light and the information light.

The present invention will be described in detail below.

The polymer of the component (A) used in the present invention has at least one ethylenically unsaturated bond in the structural unit. Specifically, a polymer obtained by reacting (meth) acrylic acid with a polymer having an epoxy ring such as glycidyl poly (meth) acrylate in the presence of a base,
Alternatively, a polymer obtained by reacting a polymer having a hydroxyl group such as 2-hydroxyethyl poly (meth) acrylate or p-hydroxystyrene with (meth) acrylic acid chloride, and further, these and various (meth) acrylic acid esters, Examples thereof include, but are not limited to, copolymers with styrene and the like. The weight average molecular weight of the polymer of component (A) must be 80,000 or more, and if the molecular weight is smaller than that, a good coating film cannot be obtained.

The polymerizable monomer which is the component (B) is a compound containing at least one ethylenically unsaturated bond, and includes an oligomer in addition to a monofunctional vinyl monomer. It may be a mixture of. Specifically, high-boiling vinyl monomers such as (meth) acrylic acid, itaconic acid, maleic acid, (meth) acrylamide, diacetone acrylamide, and 2-hydroxyethyl (meth) acrylate, and further aliphatic polyhydroxy compounds, For example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, 1,3
-Propanediol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, 1,
Di- or poly (meth) acrylic acid esters such as 10-decanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol and mannitol, aromatic polyhydroxy compounds such as hydroquinone, resorcin, catechol and pyrogallol. Or poly (meth) acrylic acid ester,
Examples thereof include ethylene oxide-modified (meth) acrylic acid ester of isocyanuric acid, but not limited thereto.

The component (C), a diaryliodonium salt, has the property of generating radicals upon irradiation with light.
The compound used in the present invention includes Macromol
ecules, 10, 1307 (1977). A compound described in, for example, diphenyliodonium, ditolyliodonium, (p-anisyl) phenyliodonium,
Bis (m-nitrophenyl) iodonium, bis (p-
Examples thereof include chloride salts such as tert-butylphenyl) iodonium, bromide salts, borofluoride salts, hexafluorophosphate salts, and hexafluoroarsenate salts.

The sensitizing compound capable of absorbing any light within the wavelength range of 400 to 550 nm which is the component (D) and capable of sensitizing the diaryl iodonium salt is a photodecomposition of the diaryl iodonium salt. It has the function of sensitizing. Specific examples of the sensitizing compound can be selected from dialkylaminobenzylidene compound derivatives, 3-ketocoumarins and the like.

The following compounds can be exemplified as the dialkylaminobenzylidene compound represented by the general formula (I).

[0015]

[Chemical 2]

The ketocoumarins are represented by the general formula (II)

[0017]

[Chemical 3]

(In the formula, R ₁ and R ₂ represent a hydrogen atom, a halogen atom, an alkoxy group, a dialkylamino group, an aryl group or a condensed benzene ring;
₃ represents a hydrogen atom or a cyano group, and R ₄ represents a lower alkyl group or an aryl group) or a 3-ketocoumarin compound represented by the general formula (III)

[0019]

[Chemical 4]

(Wherein R ₁ , R ₂ , R ₅ and R ₆ represent a hydrogen atom, a halogen atom, an alkoxy group, a dialkylamino group, an aryl group or a condensed benzene ring, and R ₃ , R ₇ Represents a hydrogen atom or a cyano group) and is at least one compound selected from bisketocoumarins carbonyl-substituted at the 3-position represented by
It is desirable that the benzene nucleus of coumarin be substituted with an alkoxy group or a dialkylamino group.

Specifically, examples of the compound represented by the general formula (II) include 3-thienoylcoumarin and 3- (4
-Methoxybenzoyl) coumarin, 3-benzoylcoumarin, 3- (4-cyanobenzoyl) coumarin, 3-thienoyl-7-methoxycoumarin, 7-methoxy-3-
(4-Methoxybenzoyl) coumarin, 3-benzoyl-7-methoxycoumarin, 3- (4-cyanobenzoyl) -7-methoxycoumarin, 5,7-dimethoxy-3
-Thienoylcoumarin, 5,7-dimethoxy-3- (4
-Methoxybenzoyl) coumarin, 3-benzoyl-
5,7-dimethoxycoumarin, 3- (4-cyanobenzoyl) -5,7-dimethoxycoumarin, 7-diethylamino-3-thienoylcoumarin, 7-diethylamino-
3- (4-cyanobenzoyl) coumarin, 7-diethylamino-3- (4-diethylaminobenzoyl) coumarin, 3- (2-benzofuroyl) -7-diethylaminocoumarin, 3-cinnamoyl-7-diethylaminocoumarin, 4-cyano- 3-Cinnamoyl-7-diethylaminocoumarin, 3- (p-diethylaminocinnamoyl) -7-diethylaminocoumarin, 3-acetyl-7
-Diethylaminocoumarin, 3-carboxy-7-diethylaminocoumarin, 3- (4-carboxybenzoyl) -7-diethylaminocoumarin and the like can be mentioned. Further, an aromatic ring may be condensed with the coumarinbenzene ring.

Next, as the compound represented by the general formula (III), 3,3'-carbonylbiscoumarin and 3,3 '
-Carbonylbis (7-methoxycoumarin), 5,7-
Dimethoxy-3,3'-carbonylbiscoumarin, 5,
7,7'-trimethoxy-3,3'carbonylbiscoumarin, 3,3'-carbonylbis (5,7-dimethoxycoumarin), 3,3'-carbonylbis (5,7-dimethoxycoumarin), 3,3 '-Carbonyl bis (5,7
-Diethoxycoumarin), 7-diethylamino-3,
3'-carbonylbiscoumarin, 7-diethylamino-
5 ', 7'-dimethoxy-3,3'-carbonylbiscoumarin, 3,3'-carbonylbis (7-diethylaminocoumarin), 3,3'-carbonylbis (julolidinocoumarin), 3,3'- Carbonyl bis (4-cyano-7-diethylaminocoumarin) and the like can be mentioned.

The amount of the component (B) contained in the hologram recording material of the present invention can be in the range of 20 to 200 parts by weight, preferably 40 to 140 parts by weight, relative to 100 parts by weight of (A). Parts by weight. The amount of the diaryliodonium salt of the component (C) is 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the component (A). Furthermore, the sensitizing dye of the component (D) can be in the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of the component (A). The amount used is limited by the film thickness of the photosensitive layer and the optical density of the film thickness. That is,
It is preferable to use it in a range where the optical density does not exceed 2.

If desired, known additives such as binders, plasticizers, thermal polymerization inhibitors and chain transfer agents may be added to the hologram recording material of the present invention.

As a visible light laser light source suitable for the hologram recording material of the present invention, a helium-cadmium laser,
Argon laser is available.

Next, a method of manufacturing a hologram will be described. First, on a support, (A) a polymer having at least one polymerizable ethylenically unsaturated bond and having a weight average molecular weight of 80,000 or more, and (B) at least one polymerizable ethylenically unsaturated bond. A compound having the above, (C)
Diaryliodonium salt and (D) 400-55
A hologram recording material comprising a sensitizing compound capable of absorbing any light within the wavelength range of 0 nm and capable of sensitizing a diaryl iodonium salt is applied by a method such as spin coating to form a photosensitive layer. After that, an oxygen barrier film such as polyvinyl alcohol was provided on the photosensitive layer.

The hologram recording material is holographically exposed by a known two-beam interference optical system. More specifically, an argon laser 488 nm light is used as the laser oscillator, and the laser light oscillated from the laser oscillator is split into two light fluxes (information light and reference light) by a beam splitter after passing through a plurality of reflecting mirrors. Further, the two light fluxes interfere with each other on the hologram recording material after passing through the lens and the pinhole to generate an interference fringe pattern, which is recorded on the hologram recording material. Then, after removing the oxygen barrier film, the hologram is obtained by drying the one immersed in a swelling solvent such as xylene, and subsequently in a shrinking solvent such as n-heptane.

[0028]

[Action]

In hologram recording, by irradiating the polymerizable photosensitive material with laser interference light, at least one polymerizable ethylenically unsaturated bond is present in a portion of the laser-irradiated portion having a strong optical interference action. The polymer (A) having at least one ethylenically unsaturated bond capable of being polymerized simultaneously with the polymerization reaction of the compound (B) has a polymerization reaction with itself or the component (B). It becomes insoluble in organic solvents.
In the laser irradiation site where light interference is weak, a compound (B) having at least one polymerizable ethylenically unsaturated bond and a compound (B) having at least one polymerizable ethylenically unsaturated bond. 2) does not cause a polymerization reaction or has a low degree of polymerization, the compound (B) is dissolved by the organic solvent for developing treatment and removed from the photosensitive film. It is presumed that this causes a difference in density between the two parts, resulting in a difference in the refractive index and hologram recording. In this method, the polymer compound as the support also has a crosslinked structure and is insoluble in the developing treatment solvent. In fact, after laser interference exposure,
The procedure of removing the oxygen barrier film, immersing the photosensitive plate in a swelling solvent to swell the polymer, removing residual monomers and dyes, and then immersing in the shrinking solvent and shrinking to the size at the time of photographing is taken. .

The hologram recording material and the method for producing a hologram of the present invention are better than conventional hologram recording materials.
The peak wavelength of reproduced light and the reproducibility of its bandwidth are excellent, the development characteristics are good, and the environment resistance is also excellent, so that it can be applied to a hologram optical element.

[0031]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

<Examples 1 to 3> Methyl methacrylate (M
MA) -glycidyl methacrylate (GMA) copolymer (molar charging ratio, weight average molecular weight are shown in Table 1) 20.00
Tetrabutylammonium chloride (TBAC) and acrylic acid (AA) were added to a solution of g in 200 ml of dimethylacetamide, and the mixture was stirred at 70 ° C. for about 4 hours. The reaction solution was poured into a large amount of methanol, the precipitate was collected and dried to obtain a polymer.

[0033]

[Table 1]

100 parts of the polymer (Experiment Nos. 1-3),
Pentaerythritol triacrylate (PETA) 7
8 parts of 0 parts and 5 parts of diphenyliodonium hexafluorophosphate and 2.5 parts of 2-benzoyl-3- (p-dimethylaminophenyl) -2-propenenitrile.
What was dissolved in 00 parts of diethylene glycol dimethyl ether was used as a photosensitive solution. The photosensitive solution was applied on a glass plate so that the film thickness was about 7 μm, and then covered with a polyvinyl alcohol (PVA) film to prepare a hologram recording photosensitive plate.

This photosensitive plate was exposed to light of an argon laser 488 nm in a two-beam interference optical system, then immersed in xylene for 1 minute to develop and swell the photosensitive layer, and heptane to 2
A reflection type hologram was produced by immersing it for 0 second and shrinking it.

The diffraction efficiency was measured by a spectrophotometer of JASCO Corporation type. The apparatus is a photomultimeter having a slit with a width of 3 mm and a radius of 20 mm with the sample as the center.
Can be installed on the circumference of cm. Monochromatic light having a width of 0.3 mm was incident on the sample at an angle of 45 degrees, and diffracted light was detected from the sample. The diffraction efficiency was defined as the ratio between the largest value other than the specularly reflected light and the value obtained when the incident light was directly received without placing the sample. The results are shown in Table 2.

[0037]

[Table 2]

These holograms were recorded at 25 ° C. and 60% RH.
No decrease in diffraction efficiency was observed even when left for 180 days in the environment.

<Examples 4 to 6> 2 in Examples 1 to 3
-Benzoyl-3- (p-dimethylaminophenyl)-
2-propenenitrile (sensitizing compound) was added to 3,3'-
Table 3 shows the results of the same operations as in Examples 1 to 3 except that carbonylbis (7-diethylaminocoumarin) was used instead.

[0040]

[Table 3]

<Examples 7 to 9> P in Examples 1 to 3
Table 4 shows the results of the same operations as in Examples 1 to 3 except that ETA (monomer) was replaced with triallyl isocyanurate (trade name Aronix M-315, Toagosei Kagaku Kogyo Co., Ltd.).

[0042]

[Table 4]

<Examples 10 to 12> The 2-benzoyl-3- (p-dimethylaminophenyl) -2-propenenitrile (sensitizing compound) in Examples 7 to 9 was mixed with 3,
3'-carbonylbis (7-diethylaminocoumarin)
Table 5 shows the results of the same operations as in Examples 7 to 9 except that the above was used.

[0044]

[Table 5]

<Examples 13 to 14> Methyl methacrylate (MMA) -2-hydroxyethyl methacrylate (HE)
MA) Copolymer (molar charging ratio; 9/1, weight average molecular weight; 190,000) 5.00 g of tetrahydrofuran 50 ml
Triethylamine (1.23 g) was added to the solution dissolved in, and acryloyl chloride (0.13 g) was added while stirring and maintaining the reaction system at 0 ° C.
After 66 g was added dropwise and the temperature was slowly returned to room temperature, the mixture was stirred for about 4 hours. The reaction solution was poured into a large amount of methanol, the precipitate was collected and dried to obtain a polymer.

100 parts of the polymer, 70 parts of the monomer, 5 parts of diphenyliodonium hexafluorophosphate, 2.5 parts of 2-benzoyl-3- (p-dimethylaminophenyl) -2-propenenitrile and 800 parts of diethylene glycol dimethyl ether. Table 6 shows the results when the same procedure as in Example 1 was carried out using the solution dissolved in Example 1 as the photosensitive solution.

[0047]

[Table 6]

<Examples 15 to 16> The 2-benzoyl-3- (p-dimethylaminophenyl) -2-propenenitrile (sensitizing compound) obtained in Examples 13 to 14 was added to
Table 7 shows the results of the same operations as in Examples 13 to 14 except that 3,3′-carbonylbis (7-diethylaminocoumarin) was used instead.

[0049]

[Table 7]

<Comparative Example 1> A hologram was prepared in the same manner as in Example 1 except that PMMA having a weight average molecular weight of 200,000 was used instead of the polymer in Example 1, but the exposure amount was 4 mJ / cm 2. ^In No. ² , the diffraction efficiency was 70%, but uneven development occurred on the entire hologram surface.

[0051]

INDUSTRIAL APPLICABILITY The hologram recording material of the present invention has excellent sensitivity in the visible light region, high resolution, and high diffraction efficiency.
It can be produced by wet-processing a hologram having excellent transparency and storage stability.

Therefore, it can be used as a recording material for HOE having extremely high performance requirements.

Claims (4)

[Claims] 1. A polymer having (A) at least one polymerizable ethylenically unsaturated bond and having a weight average molecular weight of 80,000 or more, and (B) having at least one polymerizable ethylenically unsaturated bond. A compound, (C) a diaryliodonium salt, and (D) a sensitizing compound capable of absorbing any light within the wavelength range of 400 to 550 nm and capable of sensitizing the diaryliodonium salt. A hologram recording material characterized by: 2. A sensitizing compound capable of absorbing any light within a wavelength range of 400 to 550 nm and capable of sensitizing a diaryl iodonium salt is represented by the general formula (I): (In the formula, R ₁ and R ₂ represent a lower alkyl group, X is a residue selected from a hydrogen atom, a phenyl group, an acyl group, a cyano group, an ammonio group or an alkoxycarbonyl group, and Y is an acyl group, 2. A hologram recording according to claim 1, which is a p-alkylaminobenzylidene derivative represented by a residue selected from a cyano group, an ammonio group or an alkoxycarbonyl group, and n is 0 or 1. material. 3. A sensitizing compound capable of absorbing any light within a wavelength range of 400 to 550 nm and capable of sensitizing a diaryl iodonium salt is a 3-ketocoumarin. The hologram recording material according to claim 1. 4. A polymer having (A) at least one polymerizable ethylenically unsaturated bond and having a weight average molecular weight of 80,000 or more, and (B) having at least one polymerizable ethylenically unsaturated bond. A compound, (C) a diaryliodonium salt, and (D) a sensitizing compound capable of absorbing any light within the wavelength range of 400 to 550 nm and capable of sensitizing the diaryliodonium salt. A holographic recording material characterized by being applied onto a substrate, holographically exposing the recording material provided with an oxygen blocking film, and then subjecting the product without the oxygen blocking film to wet treatment. And a method of manufacturing a hologram.