JP2009163127A - Hologram recording material and hologram recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hologram recording material having improved diffraction efficiency, and to provide a hologram recording medium having a recording layer formed by using the same. <P>SOLUTION: The hologram recording material contains zirconia fine particles having an average dispersion particle diameter of from 1 nm to 20 nm, the surface of which is modified with an alkoxysilane compound and/or an organic acid, wherein a mass ratio of the modified portion in the zirconia fine particles is controlled to 10 to 200 mass% and a viscosity of the material before cured is controlled to ≤10,000 mPa s. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hologram recording material and a hologram recording medium, and more specifically, a hologram recording material having improved diffraction efficiency by containing zirconia fine particles having a high refractive index and excellent transparency, and the hologram recording material The present invention relates to a hologram recording medium in which a recording layer is formed using.

Conventionally, holograms using light interference fringes have been used in various fields.
This hologram is a device that reproduces signal light derived from interference fringes by irradiating the recording layer on which the interference fringes are recorded. A hologram recording material having high diffraction efficiency as the recording layer is refined. Development is required.
Such a hologram recording material includes, for example, metal oxide particles such as titania, alumina, zirconia, a polymerizable monomer, and a photopolymerization initiator that initiates polymerization of the monomer when irradiated with light. Hologram recording materials have been proposed (see, for example, Patent Document 1).
JP 2005-77740 A

By the way, the conventional hologram recording material has a problem that it is difficult to achieve both the crystallinity and atomization of the metal oxide particles.
In particular, when the particle diameter of the metal oxide particles is set to 20 nm or less, fine particles with high crystallinity cannot be obtained. Therefore, even if fine particles such as zirconia and titania that are expected to have a high refractive index are used, a sufficient refractive index is obtained. In addition, when the required amount of fine particles is added to the organic component, the viscosity of the mixture increases as the ratio of the fine particles increases, so the viscosity increases before adding the required amount of fine particles. Therefore, the required amount of fine particles cannot be added, and as a result, there is a limit to improving the diffraction efficiency as a hologram recording material.

  The present invention has been made to solve the above problems, and provides a hologram recording material with improved diffraction efficiency and a hologram recording medium in which a recording layer is formed using the hologram recording material. Objective.

  As a result of intensive studies on improving the diffraction efficiency of the hologram recording material, the present inventors have modified the surface of the particles with an alkoxysilane compound and / or an organic acid and have an average dispersed particle diameter of 1 nm or more and 20 nm or less. When the zirconia fine particles are contained, even when mixed with an organic component, the viscosity of the obtained mixture before curing can be kept at 10000 mPa · s or less, and even when mixed with an organic component. It has been found that a sufficient amount of high refractive index fine particles can be contained, and therefore the diffraction efficiency can be improved, and the present invention has been completed.

  That is, the hologram recording material of the present invention contains zirconia fine particles having a surface modified with an alkoxysilane compound and / or an organic acid and an average dispersed particle diameter of 1 nm or more and 20 nm or less, and a viscosity before curing is 10,000 mPa · s or less. It is characterized by being.

  The mass ratio of the modified portion in the zirconia fine particles is preferably 10% by mass or more and 200% by mass or less of the zirconia fine particles.

  The hologram recording medium of the present invention is characterized in that a recording layer provided on a substrate is formed from the hologram recording material of the present invention.

  The content of the zirconia fine particles in the recording layer is preferably 10% by mass or more and 80% by mass or less.

According to the hologram recording material of the present invention, since the zirconia fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less are contained, both refractive index and transparency can be achieved.
In addition, since the surface of the zirconia fine particles is modified with an alkoxysilane compound and / or an organic acid, a significant increase in viscosity can be avoided even when mixed with an organic component. As a result, diffraction efficiency can be improved.

According to the hologram recording medium of the present invention, since the recording layer provided on the substrate is formed of the hologram recording material of the present invention, it has a sufficiently high refractive index and excellent diffraction efficiency.
Therefore, a hologram recording medium having a high refractive index and excellent diffraction efficiency can be provided.

The best mode for carrying out the hologram recording material and the hologram recording medium of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

"Hologram recording material"
The hologram recording material of the present invention is a material whose surface is modified with an alkoxysilane compound and / or an organic acid, contains zirconia fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and has a viscosity before curing of 10,000 mPa · s or less. It is.
Here, the reason for modifying the surface of the zirconia fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less with an alkoxysilane compound and / or an organic acid is that the polarity of the surface of the zirconia fine particles depends on the organic component used during mixing. One approach is to make it as close as possible to the polarity. By bringing the polarity of the zirconia fine particles closer to the polarity of the organic component, aggregation and reticulation of the fine particles during mixing can be avoided, and transparency can be maintained and increase in viscosity can be suppressed.

The reason why the average dispersed particle size of the zirconia fine particles is limited to 1 nm or more and 20 nm or less is that the average dispersed particle size is within the above range, and the average dispersed particle size with respect to the wavelength of light when irradiated with light. Is sufficiently small and excellent in transparency.As a result, when applied to the recording layer of the hologram recording medium, the light that forms interference fringes and the reference light during reproduction can be sufficiently guided into the recording layer, This is because the diffraction efficiency is improved.
In particular, if the average dispersed particle size is less than 1 nm, the crystallinity becomes poor and it becomes difficult to express particle characteristics such as refractive index, resulting in a decrease in diffraction efficiency, while the average dispersed particle size is 20 nm. If the zirconia fine particle exceeds the above, scattering of light in a light wavelength region of 500 nm or less increases when the zirconia fine particles are applied to the recording layer of the hologram recording medium, and the diffraction efficiency decreases.

As the surface modifier for modifying the surface of the zirconia fine particles, an alkoxysilane compound and / or an organic acid is preferably used.
As the alkoxysilane compound, a silane coupling agent is suitable. Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n- Propyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, p -Styryltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropylto Silane, 3-mercaptopropyl triethoxysilane, and the like.
These alkoxysilane compounds may be used alone or in combination of two or more.

Organic acids include carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, etc. Unsaturated carboxylic acid such as saturated carboxylic acid, acrylic acid, crotonic acid, oleic acid and elaidic acid, polysaturated carboxylic acid such as oxalic acid, malonic acid, succinic acid, glutaric acid and adipic acid, polyunsaturated carboxylic acid And aromatic carboxylic acids.
These carboxylic acids may be used alone or in combination of two or more. It is also possible to use salts of these carboxylic acids.
When used in combination with the alkoxysilane compound and the organic acid, the weight ratio of the alkoxysilane compound (AC) and organic acid _{(OA) (M AC: M} OA) is 1: 10 to 10: 1, more preferably 1 : 5 to 5: 1.

Examples of a method for modifying the surface of the zirconia fine particles using the surface modifier include a wet method and a dry method.
The wet method is a method of modifying the surface of the zirconia fine particles by introducing a surface modifier and zirconia fine particles into a solvent and mixing them.
The dry method is a method of modifying the surface of the zirconia fine particles by introducing the surface modifier and the dried zirconia fine particles into a dry mixer such as a mixer and mixing them.

  The mass ratio of the modified portion in the zirconia fine particles is preferably 10% by mass or more and 200% by mass or less of the zirconia fine particles. The reason for this is that if it is less than 10% by mass, dispersion with a nonpolar solvent becomes unstable, the light transmittance during coating decreases, or the viscosity of a mixture obtained by adding zirconia fine particles to an organic component is remarkably high. On the other hand, if it exceeds 200% by mass, it is difficult to obtain a sufficiently high refractive index due to the influence of the refractive index of the surface modifier.

  In addition to the above zirconia fine particles, this hologram recording material polymerizes the photopolymerizable monomer as a resin component constituting the recording layer of the hologram recording medium and the photopolymerizable monomer when irradiated with light of a predetermined intensity. And a photopolymerization initiator. In this hologram recording material, the zirconia fine particles are uniformly dispersed in a component containing a photopolymerizable monomer and a photopolymerization initiator.

Any photopolymerizable monomer may be used as long as it is polymerized to become a photopolymerizable polymer when irradiated with light of a predetermined intensity. For example, fluorine monomer, epoxy monomer, acrylic monomer, silsesquioxy Sun, modified polyvinyl alcohol, etc. can be illustrated.
Examples of the fluorine-based monomer include ethylene tetrafluoride, ethylene chloride trifluoride, vinyl fluoride, vinylidene fluoride, and perfluorobutenyl vinyl ether.

Moreover, you may use the mixture which selected and mixed 2 or more types among this fluorine-type monomer.
Examples of such a mixture include ethylene / tetrafluoroethylene, ethylene / trichloroethylene, tetrafluoroethylene / 6-propylene, tetrafluoroethylene / 6-propylene / vinylidene fluoride, fluoroethylene / vinyl ether. And tetrafluoroethylene / perfluoroalkyl ether, tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether, and the like.

  Epoxy monomers include vinyl-n-butyl ether, vinyl-2-chloroethyl ether, di-2,3-epoxycyclopentyl ether, triethylene glycol divinyl ether, 1,4-cyclohexanemethanol divinyl ether, trimethylol methane trivinyl ether. Ethers such as vinyl glycidyl ether, phenyl glycidyl ether, diglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyethylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, 1,6-hexanediol diglycidyl ether, p-tarsha Libutylphenyl glycidyl ether, adipic acid diglycidyl ester, orthophthalic acid diglycidyl ester, Bi Toll polyglycidyl waders ether, resorcinol diglycidyl ether, dibromophenyl glycidyl ether can be exemplified glycidyl ethers such as dibromo neopentyl glycol diglycidyl ether.

  In addition, 1,2,7,8-diepoxyoctane, 1,4-bis (2,3-epoxypropoxyperfluoroisopropyl) cyclohexane, 1,6-dimethylol perfluorohexane diglycidyl ether, 4,4′- Bis (2,3-epoxypropoxyperfluoroisopropyl) diphenyl ether, bis- (3,4-epoxycyclohexylmethyl) adipate, 1,2,5,6-diepoxy-4,7-methanoperhydroindene, 1,2- Ethylenedioxy-bis (3,4-epoxycyclohexylmethane), 2- (3,4-epoxycyclohexyl) -3 ′, 4′-epoxy-1,3-dioxane-5-spirocyclohexane, 3,4-epoxy Cyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 4 ′, 5′-epoxy-2 Examples thereof also include '-methylcyclohexylmethyl-4,5-epoxy-2-methylcyclohexanecarboxylate, ethylene glycol-bis (3,4-epoxycyclohexane) carboxylate and the like.

Examples of acrylic monomers include acrylic acid, acrylic ester, methacrylic acid, methacrylic ester and the like.
Examples of acrylic esters include methyl acrylate, ethyl acrylate, acrylic acid-n-propyl, acrylic acid-n-butyl, cyclohexyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, 2-phenylethyl acrylate, acrylic 2-phenoxyethyl acid, p-chlorophenyl acrylate, benzyl acrylate, 2- (1-naphthyloxy) ethyl acrylate, trimethylolpropane triacrylate, ethoxylated bisphenol A diacrylate, bisphenol A di (3-acryloxy-2- Hydroxypropyl) ether, bisphenol A-diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 2,2-di (p-hydroxyphenyl) propane diacrylate It can be exemplified, and the like.

  Methacrylic acid esters include methyl methacrylate, ethyl methacrylate, methacrylate-n-propyl, methacrylate-n-butyl, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, 2-phenylethyl methacrylate, methacrylic acid. 2-phenoxyethyl acid, p-chlorophenyl methacrylate, trimethylolpropane trimethacrylate, 2,2-di (p-hydroxyphenyl) propane dimethacrylate, 1,4-butanediol dimethacrylate, 1,4-benzenediol dimethacrylate 1,5-pentanediol dimethacrylate, bisphenol A di (2-methacryloxyethyl) ether, polyoxyethyl-2,2-di (p-hydroxyphenyl) propane dimethacrylate Tetrabromo-bisphenol A di (2-methacryloxyethyl) ether, tetrachloro-bisphenol A di (2-methacryloxyethyl) ether, tetrabromo-bisphenol A di (3-methacryloxy-2-hydroxypropyl) ether, diphenolic acid di Examples include (3-methacryloxy-2-hydroxypropyl) ether.

Examples of silsesquioxanes include silsesquioxanes such as polyhydridosilsesquioxane, or polysilsesquioxanes such as polymethylsilsesquioxane, polyphenylsilsesquioxane, and polyphenyl-methylsilsesquioxane. Etc. can be illustrated. The molecular weight of the polysilsesquioxane is preferably about 300 to 10000, more preferably about 1000 to 8000.
Examples of the modified polyvinyl alcohol include water-soluble acrylic-modified polyvinyl alcohol and methacryl-modified polyvinyl alcohol.

The photopolymerization initiator is not particularly limited as long as it can polymerize the photopolymerizable monomer when irradiated with light of a predetermined intensity, but a photoradical polymerization initiator is suitable.
Examples of the photo radical polymerization initiator include azide compounds, azo compounds, organic thiol compounds, titanocene compounds, organic peroxides, onium salts, iodonium salts, bisimidazole derivatives, halogenated hydrocarbon derivatives, and the like. it can. Among these photoradical polymerization initiators, particularly effective are titanocene compounds.

  The titanocene compounds include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,4,6-tri Fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,4 , 5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2, Examples thereof include 6-di-fluorophen-1-yl.

  Further, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyru-1- Yl) -phen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2 , 3,4,5,6-pentafluorophen-1-yl and the like.

"Hologram recording medium"
The hologram recording medium of the present invention is a medium in which a recording layer provided on a substrate is formed of the hologram recording material of the present invention, and a transparent protective film is formed on the recording layer.
The content of the zirconia fine particles in this recording layer is preferably 10% by mass or more and 80% by mass or less.

  In this hologram recording medium, the above-mentioned hologram recording material is applied onto a substrate using a spin coating method, a bar coating method, a roll coating method, a screen printing method, etc., and the resulting coating film is dried or heated under reduced pressure. It can be obtained by drying to form a recording layer and forming a transparent protective film made of silica or the like so as to cover the recording layer.

When this hologram recording medium is irradiated with interference light formed by superimposing reference light and recording light, a photopolymerization initiator acts on the irradiated portion to accelerate polymerization of the photopolymerizable monomer. . At this time, the zirconia fine particles present in the light-irradiated part are inactive with respect to the photopolymerization reaction, and are covered with a modifying group having a high affinity with the photopolymerizable monomer. Because it is not directly involved in the polymerization reaction and is excellent in dispersion suitability with the photopolymerizable monomer, it diffuses to the monomer site in the area not irradiated with adjacent light as the photopolymerizable monomer is accelerated. Transition. As a result, the content ratio of the zirconia fine particles in the non-light-irradiated portion is higher than that in the light-irradiated portion, and the refractive index of the non-light-irradiated portion is relatively high.
In this way, when the reference light is irradiated to the hologram recording medium on which the interference fringes are recorded, the interference fringes are reproduced by the diffraction effect corresponding to the refractive index difference.

  The wavelengths of the reference light and recording light used for this hologram recording medium are generally in the range of 250 nm to 500 nm. If the wavelength is less than 250 nm, the absorption of the photopolymerizable monomer is large and the light does not easily reach the deep part. On the other hand, if it exceeds 500 nm, the energy becomes too low, and it is difficult to start the polymerization reaction.

According to this hologram recording medium, since the recording layer is formed of the hologram recording material of the present invention, it has a sufficiently high refractive index and is excellent in diffraction efficiency.
Therefore, a hologram recording medium having a high refractive index and excellent diffraction efficiency can be provided.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

"Example 1"
As the zirconia fine particles, a nano zirconia aqueous dispersion NZD-8007 (manufactured by Sumitomo Osaka Cement) containing 40% by mass of zirconia fine particles was used. ) 200 parts by mass was added to modify the surface of the zirconia fine particles, followed by toluene substitution to obtain a toluene dispersion containing 30% by mass of zirconia fine particles.

Next, this toluene dispersion was dried at 150 ° C. and 750 ° C., and the mass ratio of the modified portion on the surface of the zirconia fine particles was determined from the mass decrease. As a result, the mass ratio of the modified moiety was 30% by mass.
Subsequently, the average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured. These measuring methods are shown below. These measurement results are shown in Table 1.

(1) Average particle size The particle size distribution of a sample prepared by adjusting the content of zirconia fine particles in the toluene dispersion to 1% by mass is measured using a dynamic light scattering type particle size distribution analyzer (manufactured by Malvern). The average particle size was determined from the measurement results.
(2) Refractive index Two types of samples in which the concentration of zirconia fine particles in the above toluene dispersion was adjusted to 10% by mass and 30% by mass were prepared, and the refractive index of each sample was set to Abbe refractometer (manufactured by Atago Co., Ltd.). The refractive index of the particles was calculated from the difference between these measured values.

Next, 200 parts by mass of this toluene dispersion, 50 parts by mass of DPHA (manufactured by Nippon Kayaku Co., Ltd.) as a photopolymerizable monomer, and 2.5 parts by mass of IRG-784 (manufactured by Ciba Geigy) as a titanocene compound as a photo radical polymerization initiator Were mixed and dissolved, and then the toluene solvent was removed by drying under reduced pressure to produce the hologram recording material of Example 1, and the viscosity was measured. The measuring method is as follows.
(3) Viscosity A B-type viscometer (model name) BL (manufactured by Toki Sangyo Co., Ltd.) was used. 2 or No. 3 was measured at a sample temperature of 25 ° C.

Next, this hologram recording material was applied onto a glass substrate using a bar coating method to obtain a coating film of Example 1.
Subsequently, the light transmittance and film thickness of this coating film were measured, and the diffraction efficiency was evaluated. These results are shown in Table 1. The measurement method and evaluation method are as follows.

(4) Light Transmittance Using a spectrophotometer (manufactured by JASCO Corporation), the visible light transmittance in the wavelength range of 350 nm to 800 nm was measured for the case where air was 100%.
(5) Film thickness It measured using the level | step difference and the surface roughness measuring device (made by KLA-TENCOL).
(6) Diffraction efficiency The case where the refractive index is 1.8 or more, the light transmittance is 90% or more, and the viscosity is 5000 mPa · s or less is “◎”, the refractive index is 1.8 or more, and the light transmittance is 90% or more. The case where the viscosity was 10,000 mPa · s or less was rated as “◯”, and the case where at least one of the refractive index, light transmittance and viscosity did not satisfy the above numerical range was marked as “Δ”.

"Example 2"
As a zirconia fine particle, a nano zirconia aqueous dispersion NZD-8007 (manufactured by Sumitomo Osaka Cement) containing 40% by mass of zirconia fine particles was used. To 500 parts by mass of this nano zirconia aqueous dispersion, 75 parts by mass of glacial acetic acid and a silane coupling agent KBM -3103 (Shin-Etsu Chemical Co., Ltd.) 190 parts by mass was added to modify the surface of the zirconia fine particles, followed by toluene substitution to obtain a toluene dispersion containing 30% by mass of zirconia fine particles.

Next, this toluene dispersion was dried at 150 ° C. and 750 ° C., and the mass ratio of the modified portion on the surface of the zirconia fine particles was determined from the mass decrease. As a result, the mass ratio of the modified moiety was 30% by mass.
The average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured according to Example 1. These results are shown in Table 1.

  Next, using this toluene dispersion, the hologram recording material and the coating film of Example 2 were produced in the same manner as in Example 1. The viscosity of the hologram recording material and the light transmittance of the coating film were obtained in accordance with Example 1. And the film thickness was measured, and the diffraction efficiency was evaluated. These results are shown in Table 1.

"Example 3"
As a zirconia fine particle, a nano zirconia aqueous dispersion NZD-8007 (manufactured by Sumitomo Osaka Cement) containing 40% by mass of zirconia fine particles was used. To 500 parts by mass of this nano zirconia aqueous dispersion, 75 parts by mass of glacial acetic acid and a silane coupling agent KBM -3103 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to modify the surface of the zirconia fine particles, followed by toluene substitution to obtain a toluene dispersion containing 30% by mass of zirconia fine particles.

Next, this toluene dispersion was dried at 150 ° C. and 750 ° C., and the mass ratio of the modified portion on the surface of the zirconia fine particles was determined from the mass decrease. As a result, the mass ratio of the modified moiety was 8% by mass.
The average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured according to Example 1. These results are shown in Table 1.

  Next, using this toluene dispersion, the hologram recording material and the coating film of Example 3 were produced in the same manner as in Example 1. The viscosity of the hologram recording material and the light transmittance of the coating film were obtained according to Example 1. And the film thickness was measured, and the diffraction efficiency was evaluated. These results are shown in Table 1.

Example 4
As the zirconia fine particles, a nano zirconia aqueous dispersion NZD-8007 (manufactured by Sumitomo Osaka Cement) containing 40% by mass of zirconia fine particles was used. To 500 parts by mass of this nano zirconia aqueous dispersion, 20 parts by mass of phthalic acid and a silane coupling agent KBM -3103 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added to modify the surface of the zirconia fine particles, followed by toluene substitution to obtain a toluene dispersion containing 30% by mass of zirconia fine particles.

Next, this toluene dispersion was dried at 150 ° C. and 750 ° C., and the mass ratio of the modified portion on the surface of the zirconia fine particles was determined from the mass decrease. As a result, the mass ratio of the modified moiety was 8% by mass.
The average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured according to Example 1. These results are shown in Table 1.

  Next, using this toluene dispersion, the hologram recording material and the coating film of Example 4 were produced in the same manner as in Example 1. The viscosity of the hologram recording material and the light transmittance of the coating film were obtained according to Example 1. And the film thickness was measured, and the diffraction efficiency was evaluated. These results are shown in Table 1.

"Comparative Example 1"
Using zirconia toluene dispersion ZRT-406 (manufactured by Sumitomo Osaka Cement) containing 30% by mass of zirconia fine particles as the zirconia fine particles, the average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured according to Example 1. did. These results are shown in Table 1.
Next, using this toluene dispersion, the hologram recording material and the coating film of Comparative Example 1 were produced in the same manner as in Example 1. According to Example 1, the viscosity of the hologram recording material and the light transmittance of the coating film were obtained. And the film thickness was measured, and the diffraction efficiency was evaluated. These results are shown in Table 1.

"Comparative Example 2"
An organosilica sol MEK-ST (content ratio: 30% by mass, manufactured by Nissan Chemical Industries, Ltd.) was used in place of the zirconia fine particles, and the average particle size and refractive index of the colloidal silica were measured according to Example 1. These results are shown in Table 1.
Next, using this colloidal silica, the hologram recording material and the coating film of Comparative Example 2 were produced in the same manner as in Example 1. According to Example 1, the viscosity of the hologram recording material, the light transmittance of the coating film, and The film thickness was measured and the diffraction efficiency was evaluated. These results are shown in Table 1.

“Comparative Example 3”
As the zirconia fine particles, nano zirconia aqueous dispersion NZD-8007 (manufactured by Sumitomo Osaka Cement) containing 40% by mass of zirconia fine particles was used, and titanate coupling agent KR-138S (Ajinomoto Fine Techno Co., Ltd.) was added to 500 parts by mass of this nano zirconia aqueous dispersion. (Manufactured) 170 parts by mass was added to modify the surface of the zirconia fine particles, followed by toluene substitution to obtain a toluene dispersion containing 30% by mass of zirconia fine particles.

Next, this toluene dispersion was dried at 150 ° C. and 750 ° C., and the mass ratio of the modified portion on the surface of the zirconia fine particles was determined from the mass decrease. As a result, the mass ratio of the modified moiety was 25% by mass.
The average particle diameter and refractive index of the zirconia fine particles in this toluene dispersion were measured according to Example 1. These results are shown in Table 1.

  Next, using this toluene dispersion, a hologram recording material and a coating film of Comparative Example 3 were produced in the same manner as in Example 1. According to Example 1, the viscosity of this hologram recording material and the light transmittance of the coating film And the film thickness was measured, and the diffraction efficiency was evaluated. These results are shown in Table 1.

  According to these evaluation results, Examples 1-4 showed favorable numerical values in all of refractive index, light transmittance, and viscosity, and excellent in diffraction efficiency, as compared with Comparative Examples 1-3. I understood that.

  The hologram recording material of the present invention has a high refractive index while maintaining a high refractive index because the surface is modified with an alkoxysilane compound and / or an organic acid and contains zirconia fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less. Since the transparency and the viscosity of 10,000 mPa · s or less can be realized, and thus the diffraction efficiency can be improved, the hologram recording medium in which the recording layer is formed using this hologram recording material is of course. Even in various industrial fields to which this hologram recording medium is applied, the effect is great.

Claims (4)

  Hologram recording material characterized in that the surface is modified with an alkoxysilane compound and / or an organic acid, contains zirconia fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and has a viscosity before curing of 10,000 mPa · s or less. .   2. The hologram recording material according to claim 1, wherein a mass ratio of the modified portion in the zirconia fine particles is 10% by mass or more and 200% by mass or less of the zirconia fine particles.   A hologram recording medium, wherein a recording layer provided on a substrate is formed of the hologram recording material according to claim 1 or 2.   4. The hologram recording medium according to claim 3, wherein the content of the zirconia fine particles in the recording layer is 10% by mass or more and 80% by mass or less.