JP3039165B2 - Optical recording film and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical recording film and other films,
In particular, the present invention relates to a hologram having high durability and a method for suitably producing the hologram.

[0002]

2. Description of the Related Art In recent years, holographic techniques for recording and reproducing interference fringes formed by light waves having coherence have been widely used in various fields such as gratings, optical demultiplexers, condensers, and laser beam scanning elements as well as display holograms. Research, development, and practical application of optical elements have been made.

[0003] As hologram recording materials, silver salt emulsions,
Gelatin dichromates, photoresists, thermoplastics, and various photopolymers have been developed. Silver salt is a commercially available hologram recording material having extremely high exposure sensitivity, and a material in which a silver halide is dispersed using a gelatin film as a support is used. Dichromated gelatin is an excellent volume phase hologram recording material with very high diffraction efficiency and low noise. This component is a material obtained by adding dichromate ion to gelatin and sensitizing it. The photoresist is used as a master when a large number of embossed holograms are copied, and plastic is used as a material to be copied. Thermoplastic is a recording material that can be repeatedly recorded and reproduced, and is recorded on a thermoplastic resin as surface irregularities.
In any of the hologram recording materials, a substance mainly containing an organic compound is used.

In general, as a technique for forming a surface unevenness on a chemically stable metal oxide glass to process a diffraction grating, there is an ultra-precision lathe processing method such as electron beam lithography, ion etching, and a diamond turning machine. .

[0005]

However, the method of processing a surface of a metal oxide glass has an advantage of using a material having excellent durability, but is not suitable for mass production and a large area. In this respect, the use of a technique for exposing to actinic radiation such as holographic exposure and photolithography makes it possible to increase the area and mass production. However, in any of the hologram recording materials, a substance mainly containing an organic compound is used, so that generally the durability is not good. For example, when the temperature reaches 250 ° C. or higher, the recorded hologram material itself is oxidized and decomposed, the recorded interference fringes are destroyed, and the optical performance is reduced. The heat resistance temperature is at most 300 degrees or less. In addition, it also has a disadvantage in that it yellows under the influence of ultraviolet rays, moisture and the like in terms of weather resistance. Further, since the temperature change of the refractive index and the temperature change of the body expansion coefficient are larger by one digit than that of the metal oxide glass, the wavefront aberration due to the temperature change is apt to occur.

Accordingly, recently, in the field of holography, hologram recording such as no need for wet processing and high heat resistance of the hologram recording film are required from the viewpoint of expanding the application of the hologram, in addition to high optical characteristics irrespective of transmission type and reflection type. Therefore, new hologram recording materials, which are radically different from the conventional ones, are being developed.

Among them, the hologram recording material disclosed in Japanese Patent Application No. 4-172534 has relatively high heat resistance.
Although it has a performance that can withstand even 00 degrees, it is inevitable that it will yellow due to ultraviolet rays in terms of weather resistance.

[0008]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned problems of the prior art and exhibits excellent optical characteristics such as high diffraction efficiency, high resolution and high transmittance, high sensitivity, etc., and at the same time, excellent environmental resistance. Optical recording film and other films having durability and durability,
And a method for manufacturing the optical recording film in a simple process.

That is, the present invention provides (1) a film-like network of an inorganic substance having a large number of minute voids inside;
(2) An optical recording film comprising a gas present in the void, wherein a porosity in the film is changed depending on a location in the film.

[0010] The present invention also relates to A.I. (1) a photopolymerizable monomer or oligomer, (2) a photopolymerization initiator, (3) an organometallic compound capable of hydrolysis and polycondensation, (4) a solvent for the organometallic compound, (5) water, And (6) a starting solution containing a catalyst for accelerating the hydrolysis of the organometallic compound was applied to a substrate, and the organometallic compound was hydrolyzed and polycondensed to form a gelled film. Thereafter, the volatile components are vaporized by drying to produce a solid optical recording film. Irradiating the optical recording film with actinic radiation; A method for producing an optical recording film having an apparent density distribution and / or surface irregularities of the metal oxide, comprising removing an organic component contained in the optical recording film.

The photopolymerizable monomers in the starting solution used for producing the optical recording film and other films in the present invention include:
A monomer containing at least one polymerizable group such as an acryloyl group, a methacryloyl group, a vinyl group and an allyl group in the molecule can be suitably used. Examples include tetrohydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyloxyethyl acrylate, phenyl carbitol acrylate,
Nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ω-hydroxyhexanoyloxyethyl acrylate, acryloyloxyethyl succinate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate,
Phenyl acrylate, naphthyl acrylate, tribromophenyl acrylate, phenoxyethyl acrylate, tribromophenoxyethyl acrylate, benzyl acrylate, p-bromobenzyl acrylate,
2,2-bis (4-methacryloxyethoxy-3,5-
Monofunctional acrylates such as dibromophenyl) propane, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, and methacrylates corresponding to these monofunctional acrylates; , 6
-Hexanediol diacrylate, butanediol diacrylate, EO-modified tetrabromobisphenol A
Polyfunctional acrylates such as diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, bisphenol A diacrylate and the like, and methacrylates corresponding to these polyfunctional acrylates; styrene, p-chlorostyrene, divinylbenzene, vinyl acetate, Vinyl compounds such as acrylonitrile, N-vinylpyrrolidone, vinylnaphthalene, and N-vinylcarbazole; and allyl compounds such as diethylene glycol bisallyl carbonate, triallyl isocyanurate, diallylidenepentaerythritol, diallyl phthalate, diallyl isophthalate, etc. Including).

Examples of the photopolymerizable oligomer in the starting solution used in the present invention include urethane acrylate oligomer, epoxy acrylate oligomer, ester acrylate oligomer in addition to the above-mentioned oligomer of the photopolymerizable monomer. , Polyfunctional oligoacrylates such as polyol polyacrylates, modified polyol polyacrylates, polyacrylates having an isocyanuric acid skeleton, and methacrylates corresponding to these acrylates (including mixtures), but are not limited thereto. Absent.

Examples of the polyurethane acrylate oligomer include those formed by an addition reaction of polyisocyanate, 2-hydroxyalkyl (meth) acrylate and polyol. Here, examples of the polyisocyanate include toluene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate. Examples of the polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, polyester polyols, polycarbonate polyols, and polysiloxane polyols.

The organometallic compounds which can be hydrolyzed and polycondensed in the starting solution used in the production of optical recording films and other films used in the present invention include organosilicon compounds, organotitanium compounds and organozirconium compounds. A compound containing at least one of a compound and an organoaluminum compound is preferable, and a metal alkoxide having an alkoxyl group is particularly preferable. Specifically, methoxide such as silicon, titanium, zirconium, and aluminum, ethoxide, propoxide, butoxide, and the like are used alone or as a mixture. Examples thereof include organic silicon compounds such as tetraethoxysilane, tetramethoxysilane and tetrabutoxysilane; organic titanium compounds such as titanium isopropoxide and titanium butoxide; organic zirconium compounds such as zirconium methoxide and zirconium butoxide; aluminum ethoxide and aluminum Organic aluminum compounds such as butoxide are exemplified. Compounds having an organic moiety in the side chain, such as dimethylsiloxane, aminosilane, and polydimethylsiloxane at the end of silanol, or compounds having a functional group that can be polymerized with other organic monomers such as vinylsilane, acrylsilane, and epoxysilane are used as organic compounds. May be modified.

In addition to the above metal alkoxides, carboxylate such as metal acetylacetonate, acetate and oxalate and metal inorganic compounds such as nitrate, chloride and oxychloride may be used.

The organometallic compound is hydrolyzed in a solution, and as the polycondensation proceeds, an inorganic network structure is formed from the sol to form a gel. When this gel is heated at a high temperature, a metal oxide solid can be produced.

In order to hydrolyze and polycondense the organometallic compound used in the present invention, a solvent, water and a catalyst for accelerating the hydrolysis are required. As the solvent in which the metal organic compound is to be dissolved, alcohols such as methanol, ethanol, propanol and butanol are most preferred. Examples of the catalyst include acids such as hydrochloric acid, acetic acid, sulfuric acid, and nitric acid, and bases such as ammonia.

Regarding the combination of the aforementioned photopolymerizable monomer or oligomer and the aforementioned organometallic compound, Japanese Patent Application No.
In 172534, there is a difference in the refractive index of each polymer, and preferably, the larger the difference is, the higher the diffraction efficiency is. However, in the present invention, the combination should be selected independently of the refractive indices of both polymers. Can be. This is because, as described later, organic polymer photopolymerizable monomer or oligomer is Deki by polymerization are removed by about Engineering after, during the optical recording film leaving only the network of inorganic, the gap of the air This is because such a gas exists.

In order to polymerize the above-mentioned photopolymerizable monomer or oligomer by actinic radiation, it is necessary to add a photopolymerization initiator thereto. Examples of the photopolymerization initiator of the present invention include the following compounds. For example,
2,3-bornanedione (camphorquinone), 2,
Cyclic cis-α- such as 2,5,5-tetramethyltetrahydro-3,4-furanic acid (imidazoletrione)
Dicarbonyl compound, 3,3 ′, 4,4′-tetra-
Benzophenones such as (t-butylperoxycarbonyl) benzophenone, diacetyl, benzyl, Michler's ketone, diethoxyacetophenone, ketones such as 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, benzoyl peroxide, di-t Peroxides such as -butyl peroxide, azo compounds such as allyldiazonium salt, N-
Aromatic carboxylic acids such as phenylglycine, xanthenes such as 2-chlorothioxanthone and 2,4-diethylthioxanthone, diallyliodonium salts, triallylsulfonium salts, triphenylalkylborates, iron arene complexes, bisimidazoles, and polyhalogens Compound,
Phenylisoxazolone, benzoin ethyl ether, benzyldimethyl ketal, and the like (including mixtures). Further, examples of the auxiliary include amines, thiols, p-toluenesulfonic acid and the like.

The starting solution for the optical recording film is represented by the main components, and the total amount of the photopolymerizable monomer or oligomer is 10 to 80% by weight, the photopolymerization initiator is 0.05 to 30% by weight, and the organometallic compound is 5 to 90%. It is preferable to contain 5 to 90% by weight of a solvent for the organometallic compound, 0.01 to 30% by weight of water, and 0.05 to 30% by weight of a catalyst. The total of the photopolymerizable monomers or oligomers is less than 10% by weight, or 80
If the amount exceeds 10% by weight, it becomes difficult to obtain high diffraction efficiency. Similarly, the organometallic compound is less than 5% by weight or 90% by weight.
If it exceeds, high diffraction efficiency cannot be obtained. This composition may contain, if necessary, 0.01 to 10% by weight of a photosensitizer,
A plasticizer can be contained at 0.01 to 10% by weight.

If the photopolymerizable monomer or oligomer to be used is a liquid having a low viscosity, a solvent is not necessary, but if it is a solid or has a high viscosity, a solvent for dissolving it is used. Use Examples of this solvent include toluene, dioxane, chloroform,
Dichloromethane, methylene chloride, tetrahydrofuran and the like can be used. However, when the photopolymerizable monomer or oligomer is dissolved in the above-mentioned solvent for the organometallic compound, for example, isopropyl alcohol is a solvent for tetraethoxysilane (an organometallic compound capable of hydrolysis and polycondensation) and Isopropyl alcohol, which is a solvent for the organometallic compound, also serves as a solvent for the photopolymerizable monomer or oligomer because it is also a solvent for 2-hydroxy-3-phenoxyhexyl acrylate (solid photopolymerizable monomer). be able to.

Further, organometallic compounds capable of hydrolysis and polycondensation reaction, such as dimethylsiloxane, aminosilane and silanol-terminated polydimethylsiloxane, γ-methacryloxypropyltriethoxysilane, γ-glucidyloxypropyl as silicon compounds The inorganic network structure may be organically modified with triethoxysilane to form an organic-inorganic composite. That is, among the above compounds, for example, dimethylsiloxane, polydimethylsiloxane,
In combination with an organometallic compound capable of hydrolysis and polycondensation, for example, tetraethoxysilane, it is also possible to introduce an organic group into the siloxane inorganic network structure to impart flexibility, whereby the film before heating can be formed. Handling becomes easy.

A plasticizer can be added to the starting solution for an optical recording film. The plasticizer is used to impart plasticity to the photopolymerizable monomer (or oligomer) in the optical recording composition. Examples of the plasticizer include triethylene glycol dicaprylate, triethylene glycol diacetate, and triethylene glycol. Glycol dipropionate, glyceryl tributyrate, tetraethylene glycol diheptanoate, diethyl adipate, diethyl sebacate, tributyl phosphate and the like can be mentioned.

Further, a sensitizer such as a dye can be added to the starting solution for an optical recording film. This is because the polymerization reaction is efficiently caused by actinic radiation. Examples of the dyes used include the following compounds, but are not limited thereto. For example, when visible light is used, it is a compound having absorption in the visible light region (including a mixture) such as methylene blue, acridine orange, thioflavin, ketocoumarin, erythrosin C, eosin Y, merocyanine, phthalocyanine, and porphyrin.

It is also very useful to add a leveling agent and other additives to the starting solution of the present invention, in addition to the above components, to form a uniform coating film.

Next, a method for recording light using the starting solution of the present invention will be described. To prepare an optical recording material, a photopolymerizable oligomer, a monomer, a photopolymerization initiator, and a dye are dissolved in an organic metal compound solution containing water, a solvent, and an acid or base serving as a catalyst. For example, for example, methanol, ethanol, isopropanol, toluene, dioxane, chloroform, dichloromethane, methylene chloride, tetrahydrofuran and other solvents (including a mixture thereof) are used. The use amount of these solvents is usually 10 to 1000 parts by weight based on 100 parts by weight (excluding the solvent) of the main component of the optical recording composition.

After that, a starting solution for optical recording is prepared at the above composition ratio, and this liquid material is coated on a smooth substrate surface such as a glass plate or a silicon substrate by various coating methods. . As a coating method, various methods such as spin coating, dip coating, bar coating, flow coating (curtain coating), a method using a doctor blade, and an applicator can be applied.

Thereafter, the coating film is kept at a constant temperature for a certain period of time at room temperature or in a heated state, and if necessary, further under reduced pressure, to remove the solvent or photopolymerizable compound contained in the starting solution. The volatile components such as the solvent, water, and catalyst used when dissolving the oligomer or monomer are evaporated and removed from the coating film, and the organometallic compound is hydrolyzed into the inorganic network structure formed by the polycondensation reaction. It is obtained in a state where a solid optical recording film in which photopolymerizable oligomers, monomers, photopolymerization initiators, photosensitizers, etc. are uniformly incorporated is coated on a smooth substrate surface. Actually, even if these volatile components are not completely removed but remain up to about several weight%, there is no problem as long as a substantially solid film can be obtained.
The thickness of the optical recording film after drying is usually 0.01 to 100 μm.
It is. Thereafter, a resin film or a glass plate transparent to the active radiation irradiated or exposed in the next step is covered on the surface of the obtained optical recording film by an appropriate method. This is because the polymerization of the present composition proceeds by radical polymerization to prevent the polymerization from being inhibited by oxygen and to prevent adhesion of dust and foreign matter.

Next, a step of exposing the covered optical recording film to actinic radiation is performed. Actinic radiation is ultraviolet light,
Radiation that can cause a polymerization reaction of photopolymerizable oligomers and monomers by irradiation, such as radiation such as visible light and infrared light, an electron beam, and an ion beam. As this step, for example, there is a method of exposing to an interference fringe obtained by coherent radiation. In general, a known method using a laser light source as a coherent light source is used. The interference exposure can be performed using a known holographic exposure optical system. Usually, this method is called a two-beam interference exposure method. Laser light oscillated from a laser oscillator is divided into two parallel lights or diffused lights by using a beam splitter, a beam expander, a collimator lens and the like. Then, one of the light beams is incident on the optical recording material as reference light. For example, when recording an object image, the other light beam is applied to the object, and the light reflected from the object is incident on the optical recording material as object light. At this time, the reference light and the object light form interference fringes, and the interference fringes are recorded on the optical recording film to obtain an optical recording film (hologram).

As a method of exposure to actinic radiation,
In addition to the interference exposure method, a method using a patterning mask may be used. A method in which a mask having a predetermined pattern formed of a substance that does not allow radiation to pass therethrough is placed on the optical recording film, and for example, the radiation of a high-pressure mercury lamp is exposed through a patterning mask. Further, a method of scanning an active radiation beam having a constant diameter may be used.

The time of exposure to actinic radiation varies depending on the intensity of the actinic radiation, the recording area, and the like.
1 second to 30 minutes, total exposure 0.1 to 1000 mJ / c
are exposed so that m ^2.

[0032] The following optical recording film as engineering exposed to actinic radiation, light unpolymerized photopolymerizable oligomer remaining recording material, the polymerization of the monomers was completed, and a photopolymerization initiator unreacted and It is preferable to go through a step of inactivating a photosensitizer such as a dye.

In this step, uniform actinic radiation irradiation capable of causing a polymerization reaction can be performed on the entire surface of the optical recording film after being exposed to actinic radiation. By this uniform irradiation, the polymerization of the unpolymerized oligomer and monomer in the optical recording film is completed, and the formed composition distribution is fixed. This step is performed so that the total exposure is usually about 10 to 10000 mJ / cm ² . However, even if this step is not performed, the same effect can be obtained by the step of removing an organic component described below.

[0034] As extent following engineering is performed to remove organic components from the optical recording film obtained by the above process. The organic component includes not only the above-described organic polymer in which the photopolymerizable monomer or oligomer is polymerized, but also unpolymerized monomers, oligomers, and residues such as a photopolymerization initiator, a dye, and a solvent. As the method, for example, a method of heating to a temperature of at least 200 degrees or more can be mentioned.
The organic components in the optical recording film are oxidized and decomposed by the heat treatment, are removed from the optical recording film, and the trace of the removal remains as a void, where a gas such as air is present. This heating temperature also depends on the organic compound to be removed such as the photopolymerizable monomer, oligomer or solvent used. Further, it is preferable to heat the optical recording film to a high temperature in order to increase the denseness of the optical recording film and increase the mechanical strength. Therefore, the heating temperature range is preferably about 200 ° C. to 1200 ° C., and the heating time is preferably at least 1 minute or more.

Other methods for removing organic components from the optical recording film include a method in which the organic components are oxidized and decomposed by ozone generated by irradiating ultraviolet rays of about 184 nm, or a method in which the organic components are eluted using a solvent. No. Also it may be used in combination as these factories.

[0036] In this step, the water remaining in being optical recording film, a catalyst, an organic component is removed becomes void, inorganic component (metal oxide) remains. At that time, the composition distribution of the inorganic network structure and the organic polymer modulated by optical recording is recorded as the modulation of the inorganic network structure. Since the film obtained in this step does not contain any organic components, it has excellent heat resistance, weather resistance, and environmental resistance.

The porosity of the film (in other words, the apparent density of an inorganic substance (metal oxide)), for example, per unit minute volume of the film (per 10 −21 cubic m)
If the porosity of but you change the location of a modulation by the membrane surface of the optical recording, to heat the inorganic material such as silica constituting the inorganic network structure to a high temperature, for example about 300 ° C. or higher, such as to be able to deform in the above step Due to the surface tension of the inorganic substance, the film part with a relatively small density of the inorganic substance shrinks more than the film part with a relatively large density, and controlled irregularities are formed on the surface of the film. You.

Next, the principle of the present invention will be described.

In a solution of an organic metal compound containing a certain amount of a solvent, water and an acid or base as a catalyst, a photopolymerization initiator,
Then, a photopolymerizable monomer or oligomer containing additives such as a photosensitizer and a plasticizer is added as required, followed by stirring and mixing. The uniformly mixed solution is coated on the substrate by various methods to obtain a film. At this stage, the film is a film made of a viscous liquid, but as time elapses after coating, hydrolysis and polycondensation of the organometallic compound progress to form an inorganic network structure and change from a sol to a gel state. Further, by performing forced drying or natural drying, volatile components such as solvent and water contained in the inorganic network structure evaporate, and as a result, a solid optical recording film is obtained.

In the optical recording film before exposure to the actinic radiation, the photopolymerizable monomer or oligomer is uniformly held in the inorganic network structure formed on the entire film. yo Ru actinic radiation exposure, or etc. mask pattern exposure to an interference pattern formed
During exposure Engineering enough for selectively polymerized by light intensity distribution inside an optical recording layer is started. That is, the polymerization is started in the portion where the light intensity is high, and the monomer is consumed accordingly, so that the monomer is supplied from the adjacent portion where the light intensity is low to the portion where the light intensity is high, and the polymerization is further promoted. At this time, a part of the inorganic network structure originally existing in the portion where the light intensity is strong is extruded by the polymer whose volume has been increased by the monomer supplied from the portion where the light intensity is weak, and the adjacent portion where the light intensity is weak. The organic polymer-rich region where the photopolymerizable monomer (or oligomer) is polymerized, which is a portion where the light intensity is high, and a portion where the light intensity is weak, on the contrary, This is considered to be divided into an inorganic network structure rich region and a large composition difference occurs between the two regions. At this time, the refractive index Np of the organic polymer obtained by polymerization of the photopolymerizable monomer (or oligomer) and the refractive index Nm of the inorganic network structure (the refractive index of the inorganic substance formed by hydrolysis and polycondensation of the organometallic compound) An optical recording film utilizing this difference is Japanese Patent Application No. 4-172534 filed by the present applicant.

In the optical recording film of the present invention, the organic polymer contained therein or the reaction is not completed from the recording film in which the composition distribution of the organic polymer component and the inorganic network structure is formed by the above-mentioned exposure to actinic radiation. Organic components such as oligomers and monomers of the above are removed. Therefore, Japanese Patent Application No. 4
Rather than utilizing the difference between the refractive index Np of the polymer and the refractive index Nm of the inorganic network structure indicated by 172534, air existing in the space from which the organic component emerged and the refractive index Nm of the inorganic network structure Since the difference between the refractive index of the gas and the organic polymer compound is selected, there is no restriction on the refractive index when selecting a combination of the photopolymerizable monomer or oligomer and the organometallic compound, so that more combinations are possible.

The optical recording film is made porous by the step of removing the organic component of the present invention, and the whole shrinks to a thickness of about 1/2 to 20 in the thickness direction. Although this film also tends to shrink in the plane direction, it hardly actually shrinks in the plane direction because it is constrained by the base material. At this time, two types of changes can occur. In the first type, the porosity of the region is increased by removing the organic components in the organic polymer-rich region. In contrast, the porosity of the region rich in the inorganic network structure is lower than that of the region rich in the organic polymer. The low porosity portion has a higher apparent refractive index than the high porosity portion. That is, in this case, the light intensity distribution is recorded as a porosity distribution. In other words, the apparent density of the inorganic material in the film portion to which the light of high intensity is applied becomes lower, and conversely, the apparent density of the inorganic material in the film portion to which the light of lower intensity is applied becomes higher. As an organometallic compound capable of hydrolysis and polycondensation, the use of an organotitanium compound rather than an organosilicon compound results in a larger apparent refractive index difference between a low porosity portion and a high porosity portion. Become. The reason is that titanium oxide constituting the inorganic network structure is silicon oxide (refractive index =
This is because it has a higher refractive index (2.35) itself than 1.46). In the second type, when the porous film is further densified following the change of the first type, the region which is rich in the organic polymer having a high porosity is relatively relatively formed compared to the region which is rich in the inorganic network structure. This is the case where surface irregularities are formed on the recording film because the shrinkage increases. At this time, a region having a high light intensity forms a concave portion, and a region having a low light intensity forms a convex portion. The height of the unevenness depends on the composition of the recording film, the thickness of the film, the light intensity distribution to be irradiated, the heating temperature, and the like.
An uneven height of 1 μm to 10 μm results.

The surface unevenness or the pore distribution depends on conditions such as the compound used for the inorganic component, the concentrations of the organic component and the inorganic component, and the temperature of the heat treatment. When the heat treatment temperature is extremely high, the porosity of both the organic polymer rich region having a high porosity and the inorganic network structure rich region becomes zero, and only surface irregularities are formed. It is also possible to form both surface irregularities and pore distribution. When forming both the surface irregularities and the pore distribution, they work additively as an optical recording film.

Although it has been described above that no pore (void) distribution occurs in the thickness direction of the film, actually, the pore distribution often occurs also in the thickness direction and the plane direction of the film. This is particularly noticeable when exposing to interference fringes obtained by coherent radiation.

[0045]

According to the present invention, the present invention has excellent durability such as light resistance, heat resistance and environmental resistance, which is composed of chemically stable inorganic components, and has high diffraction efficiency, high resolution and high transmittance. An optical recording film exhibiting excellent optical characteristics such as the above can be obtained. Further, according to the present invention, it is possible to obtain a thin film subjected to fine unevenness processing.

[0046]

The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples. <Description of Compounds Shown Below> TEOS: tetraethoxysilane PDMS: polydimethylsiloxane having terminal silanol group THF: tetrahydrofuran i-PA: isopropyl alcohol HCl: 12N hydrochloric acid Ti (OPr) ₄ : tetraisopropoxytitanium HPPA: 2-hydroxy- 3-phenoxypropyl acrylate EBPA: ethoxylate bisphenol A diacrylate BTTB: 3,3 ', 4,4'-tetra- (t-butylperoxycarbonyl) benzophenone (manufactured by NOF Corporation, purity: 50%) KCD: 3,3 '-Carbonylbis (7-diethylaminocoumarin) (manufactured by Japan Photographic Dye Laboratories) Example 1 First, a starting solution for an optical recording film was prepared under the following conditions. <Solution 1> ---------------------------------------------- ------ TEOS (as an organometallic compound capable of hydrolysis and polycondensation) 27 g PDMS (same as above) 3 g THF (solvent) 5 cc i-PA (solvent) 9 cc ---------- -------------------------------------------- <Solution 2>- -------------------------------------------------- ---------- i-PA (solvent) 12cc H2O (for hydrolysis of TEOS and PDMS) 2cc HCl (concentration 12N ) (catalyst to promote hydrolysis) 5cc ------ -------------------------------------------------- ------ Solution 1 and solution 2 were separately prepared and stirred, and then solution 2 as a catalyst for hydrolysis and polycondensation reaction was added dropwise to solution 1 with stirring to obtain a uniform solution. Then, the solution is heated to 80 ° C.
For 40 minutes to obtain a solution of an organometallic compound.

Next, under a lamp for a red dark room, the photopolymerization initiator BTTB and the dye KCD were dissolved in a mixed solution of methylene chloride and methanol in the following weight ratio, and the solution 3 obtained by mixing and stirring the photopolymerized monomers HPPA and EBPA was used. And 5.0 g of a solution of the above-mentioned organometallic compound (mixture of solutions 1 and 2), followed by stirring and mixing to obtain a uniform starting solution for optical recording.

<Solution 3> ------------------------------------------- --------------------- HPPA (photopolymerization monomer) 4.75 g EBPA (photopolymerization monomer) 0.25 g BTTB (photopolymerization initiator) 0.50 g KCD (Dye) 0.01 g Methylene chloride / methanol (= 95/5% by weight) (solvent) 1.00 g -------------------------- -------------------------------------- Put this solution under a red dark room lamp at 300x 150 × 2
A glass substrate having a thickness of about 9.5 μm was coated by using an applicator, allowed to stand at 30 ° C. for about 24 hours, gelled, and dried to obtain a crack-free photosensitive layer having a thickness of about 9.5 μm. Thereafter, a cover film of polyethylene terephthalate having a thickness of 100 μm is adhered onto the above-mentioned photosensitive layer, which is cut, and a photosensitive material comprising a laminate of a glass substrate having a size of 60 × 60 mm, a photosensitive layer and a polyethylene terephthalate film ( Optical recording film) was obtained.

Next, in the optical system shown in FIG. 1, the wavelength oscillated from the argon ion laser 1 is 514.5 nm.
Through the shutter 2, the beam expander 3 and the collimator lens 4 convert the light into parallel light, and the beam splitter 5 splits the light into two parallel light beams.
Using 6 ′, the three photosensitive materials (laminate of glass substrate-optical recording layer-polyethylene terephthalate film) were incident at an angle θ and subjected to interference exposure. Note that the angle θ
Are 5 °, 14 °, and 42 °, respectively, and 30 to 5
It was produced at an exposure of 0 mJ / cm ² .

After the interference exposure, the photosensitive material was exposed to the entire surface for about 15 minutes from a distance of 3 cm using a fluorescent lamp of 30 W to complete the polymerization of the unpolymerized monomer and fix it.

As described above, about 170, 48
A diffraction grating was produced using interference fringes having a spatial frequency of 0.1400 lines / mm.

Next, after the polyethylene terephthalate film was peeled off from the diffraction grating, it was heated to 500 ° C. at a heating rate of 50 ° C./hour in an electric furnace. After maintaining the temperature for 4 hours, the inside of the electric furnace was cooled down to room temperature over about 10 hours, and the diffraction grating was taken out. In this way, a 1.2 μm-thick SiO 2 film on which a diffraction grating having spatial frequencies of 170, 480 and 1400 lines / mm was recorded and a laminate of a glass substrate were obtained. The cross section of this SiO2 film is 1000 times
Observation with a 50,000 × electron microscope confirmed that surface irregularities and a slight density distribution of silica particles were formed according to the intensity of the interference fringes. That is,
The height of the mountain-shaped projections on the surface is about 1 μm, the width is about 1 μm, and the pitch of the unevenness (the distance between the centers of the projections) is about 6 μm, about 2 μm, and about 0.7 μm, respectively, according to the spatial frequency.
m. Inside the film, silica particles (diameter: about 0.01 to 0.1 μm) exist tightly inside the convex part, while the concave part is rough (many voids).
It has been confirmed that it exists. The function as a diffraction grating is mainly due to the unevenness of the film surface.

Example 2 On the photosensitive material used in Example 1, a USAF test target (manufactured by Meles Griot, spatial frequency: 1 to 228 lines / m)
m) was mounted as a masking plate, and exposed to a 2 kW ultraviolet lamp for 5 seconds at a distance from the light source of 30 cm. After peeling off the polyethylene terephthalate film,
In an electric furnace, heating was performed at a heating rate of 50 ° C./hour up to 500 ° C. After maintaining the temperature for 4 hours, the inside of the electric furnace was cooled down to room temperature over about 10 hours, and the photosensitive material was taken out.
When observing the surface of this SiO2 film with an electron microscope,
It was confirmed that surface irregularities were formed according to the mask pattern.

Embodiment 3 Next, an embodiment in which TiO2 has an inorganic network structure will be described.
A starting solution for an optical recording film was prepared by the following method. <Solution 4> ------------------------------------------- Ti (OPr ) 4 20g i-PA 20cc ------------------------------------------- <Solution 5> ------------------------------------------- i-PA 40cc H2O 2.0cc HCl (concentration 12N ) 0.5cc ------------------------------------- ------ After Solution 4 and Solution 5 were separately stirred, Solution 5 which is a catalyst for hydrolysis and polycondensation was gradually added dropwise to Solution 6 while stirring to obtain a uniform solution. <Solution 6> ---------------------------------------------- ---------------- HPPA 4.75 g EBPA 0.25 g BTTB 0.50 g KCD 0.01 g Methylene chloride / methanol (= 95/5 wt%) 1.00 g --- -------------------------------------------------- --------- Next, under a lamp for a red dark room, the photopolymerization initiator BTTB and the dye KCD were dissolved in a mixed solution of methylene chloride and methanol at the weight ratio shown in the solution 6, and the photopolymerizable monomer H was dissolved.
Solution 6 mixed and stirred with PPA and EBPA was introduced into 10.0 g of the above-mentioned solution of the organometallic compound (mixture of solutions 4 and 5), and mixed by stirring to obtain a uniform starting solution.

Coating was performed in the same manner as in Example 1, an optical recording film was obtained, and a diffraction grating was recorded using interference fringes having a spatial frequency of 1400 lines / mm.

632.8 oscillating from He-Ne laser
The diffraction efficiency was measured using a nm beam. Diffraction efficiency was calculated as the ratio of the first-order diffracted light intensity to the incident light intensity. Table 1 shows the results. At the time of performing the entire surface exposure using a fluorescent lamp, the diffraction efficiency was slightly 0.022, but gradually increased as the heat treatment was performed.
A diffraction efficiency of about 0.5 was obtained by the heat treatment at 400 to 500 degrees.

Observation of the cross section of this TiO2 film by an electron microscope confirmed that the pore distribution was mainly formed according to the intensity of the interference fringes, and that the surface was slightly uneven. The reason why the diffraction efficiency of the diffraction grating is improved after heating compared to before heating is that the difference in the refractive index between the organic polymer-rich region and the inorganic network structure-rich region due to the incident light intensity distribution is due to the polymer (HPPA) before heating. And EBPA copolymer) of about 1.55 and a refractive index of titanium oxide gel of 1.6 (about 0.05), whereas
In the diffraction grating heated at 00 ° C., the difference between the refractive index of titanium oxide of about 2.35 and the refractive index of air of about 1.00 (about 1.3).
5) is due to the fact that the difference is much larger than that before heating.

[0058]

[Table 1] ----------------------------------------

[Brief description of the drawings]

FIG. 1 is an example of an optical system used when recording a transmission diffraction grating as an embodiment of the present invention.

[Explanation of symbols]

 1. Laser oscillator, 2. Shutter, 3. Beam expander, 4. Collimator lens, 5. Beam splitter, 7. Photosensitive material,

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁷ identification code FI G11B 7/24 516 G11B 7/24 516 (56) References JP-A-64-51334 (JP, A) JP-A-2-5062 (JP, A) Patent 2953200 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/027 G03F 7/004 G03F 7/028 G03H 1/02 G11B 7/24

Claims (8)

(57) [Claims] 1. A. First Embodiment (1) a photopolymerizable monomer or oligomer, (2) a photopolymerization initiator, (3) an organometallic compound capable of hydrolysis and polycondensation, (4) a solvent for the organometallic compound, (5) water, and (6) the catalyst for accelerating the hydrolysis of the organometallic compound, only containing the content of the organic metal compound is 5-90 wt%
The starting solution is coated on the substrate, the volatile components in the coating film evaporates, is removed, the organometallic compound is hydrolyzed,
In the network structure of the metal oxide formed by polycondensation
A step of forming an optical recording film holding a photopolymerizable monomer or oligomer on the substrate , B. Irradiating the optical recording film with actinic radiation , the film
In addition, the photopolymerizability in a portion where the light intensity is strong in the film
Monomer or oligomer polymerizes and organic polymer
And the acid of the metal in the area where the light intensity is low.
B. forming a region rich in oxides, and then C.I. When the organic polymer of the irradiated film is rich,
Polymerized and unpolymerized monomer orientation in both the region and the region rich in oxides of the metal.
The organic components including sesame are removed to remove the organic components.
Metal oxide film with many microvoids
Leaving a network of the porosity in the film and the light intensity portion and light
A base material having an apparent density distribution and / or surface unevenness of the metal oxide , which is changed between a portion having a low strength and a portion having a low strength
A method for producing an optical recording film coated on the surface . 2. A process according to claim 1, wherein the optical recording film removal of the organic component carried out by heating the optical recording film 200 ° C. or higher. 3. A. (1) Photopolymerizable monomer or oligo
Ma, (2) a photopolymerization initiator, (3) Organometallic compounds capable of hydrolysis and polycondensation
object, (4) a solvent for the organometallic compound, (5) water, and (6) To promote the hydrolysis of the organometallic compound
Catalyst, And the content of the organometallic compound is 5 to 90% by weight.
Is applied onto the substrate, and the volatile solution
The organic metal compound is hydrolyzed,
In the network structure of the metal oxide formed by polycondensation
Optical recording with photopolymerizable monomer or oligomer retained
Forming a film for the substrate on the substrate, B. Irradiating the optical recording film with actinic radiation, the film
In addition, the photopolymerizability in a portion where the light intensity is strong in the film
Monomer or oligomer polymerizes and organic polymer
And the acid of the metal in the area where the light intensity is low.
The process of forming a region rich in oxides, and then C. When the organic polymer of the irradiated film is rich,
Region and the region rich in oxides of the metal
Of polymerized polymer and unpolymerized monomer
The organic components including sesame are removed to remove the organic components.
Metal oxide film with many microvoids
The process of leaving the network of Wherein the removal of the organic component comprises
The recording film is formed at a temperature at which the metal oxide can be deformed.
This creates controlled irregularities on the surface of the film
A method for producing an optical recording film coated on a substrate surface. 4. An unpolymerized light is provided between the step B and the step C.
Process to complete polymerization of polymerizable monomers and oligomers
The optical recording film according to claim 1, further comprising:
Production method. 5. The method according to claim 1, wherein the actinic radiation is irradiated using interference fringes obtained by coherent radiation .
5. The method for producing an optical recording film according to any one of items 4 to 5 . 6. The method according to claim 1, wherein the irradiation with the actinic radiation is performed for the optical recording.
Through a patterning mask placed on the film
The method for producing an optical recording film according to any one of claims 1 to 4. 7. The method of claim 1, wherein the starting solution comprises the photopolymerizable monomer.
Or a total of 10 to 80% by weight of the The photopolymerization initiator 0.05 to
30% by weight, The organometallic compound 5
90% by weight, The solvent 5
90% by weight, The water 0.01-
30% by weight, and The catalyst 0.05-
30% by weight, The optical recording film according to any one of claims 1 to 6, comprising:
Production method. 8. The organic metal compound is an organosilicon compound.
Substances, organic titanium compounds, organic zirconium compounds and
Less selected from the group consisting of organoaluminum compounds
8. The composition according to claim 1, wherein the composition comprises at least one kind.
3. The method for producing an optical recording film according to item 1.