JPH02301032A - Silicon dioxide-coated optical information recording medium and its production - Google Patents

Abstract

PURPOSE:To obtain the recording medium excellent in resistance to moisture, corrosion, scuffing and heat by laminating a silyl peroxide compd. layer and an SiO2 film on a synthetic resin substrate and treating the material under conditions where the silyl peroxide compd. is thermally decomposed. CONSTITUTION:A dielectric layer of SiAlON, a recording layer of TbFeCo and a protective layer of SiAlON are laminated on an optical disk substrate of polycarbonate resin to form a recording medium. A layer of the compd. shown by the formula and an SiO2 film are further laminated. In the formula, R is the same or different 1-6 C hydrocarbonic group, a vinyl group, a methacryloxy group, an epoxy group, an amino group, a mercapto group, an org. group having fluorine and an org. group having chlorine, R' is the same or different alkyl group, an acyl group and an arylalkyl group, and (n) is an integer of 1-4. The compd. is then thermally decomposed to generate a free radical, hence the compd. is chemically bonded by the action of the radical to attach SiO2 firmly to the substrate surface, and a recording medium having excellent characteristics is obtained.

Description

[Industrial application field]

The present invention relates to an optical information recording medium whose entire surface is coated with a silicon dioxide film, and more specifically, to moisture resistance. The present invention relates to a silicon dioxide-coated optical information recording medium with improved corrosion resistance and scratch resistance, and a method for manufacturing the same.

[Background Art] In recent years, many types of optical information recording media such as optical discs and video discs have been developed and are commercially available. These optical information recording media have a basic structure that focuses laser light onto a rotating disk and detects the strength of the reflected light from the disk. A typical example is one in which a recording layer is provided on a substrate. By the way, as recording medium materials used for the recording layer,
Metals or metal alloys with T e % Ti, Te low oxides, organic dye thin films, silver salt thin films, photochromic compounds, etc. have been widely proposed and used, but all of these are susceptible to oxidation and hydrolysis. Since the recording layer is a material that is easily damaged, development of a protective layer to prevent the recording layer from deteriorating is progressing. In addition, in optical information recording media that use synthetic resin substrates, warping occurs due to water absorption and swelling of the substrate, which may cause the recording layer to peel off, signal reading to become impossible, or the amount of water that permeates. This causes problems such as deterioration of the recording layer. Therefore, how to solve these problems and ensure the long-term reliability of optical information media has become an important issue. Conventionally, it has been proposed to provide various synthetic resin layers or transparent dielectric layers such as silicon dioxide on the surface of the recording layer as a protective layer. For example, in JP-A No. 61-39949, one to two molecular layers of a silane coupling agent or a titanium coupling agent are provided on the surface of an optical information recording layer provided on one side of a transparent substrate. Alternatively, it has been proposed to improve moisture resistance and corrosion resistance by forming polyvinylidene chloride copolymer-containing layers on both surfaces of the recording layer and the substrate. However, when only the surface of the recording layer is protected with a polyvinylidene chloride copolymer-containing layer, it is not possible to block moisture permeating from the substrate surface side. It is not possible to prevent deterioration of the recording layer due to peeling or permeated moisture, and this problem also occurs when the surface of the recording layer is covered with a dielectric layer. Further, even in optical information recording media having a structure in which a reflective layer is provided on the surface of the recording layer or a reflective layer is provided via a dielectric layer, the problem of water absorption from the substrate side cannot be solved. On the other hand, if a polyvinylidene chloride copolymer-containing layer is formed on both the surfaces of the recording layer and the substrate, the surface of the substrate, which serves as the light path, will have poor scratch resistance (a grease-resistant layer will be formed, resulting in signal degradation). There is a risk that the basic performance as an optical information recording medium will be significantly impaired, such as deterioration of sensitivity or deterioration of sensitivity.Furthermore, even if layers containing polyvinylidene chloride copolymer are formed on both surfaces, moisture resistance will not be sufficient. It is not possible to completely prevent the deterioration of the recording layer due to permeated moisture.Furthermore, some optical information recording media have structures such as adhesive bonded structures and air sandwich structures, which have two-sided structures with the recording layer as the center layer. Due to the laminated structure, the problem of warping is alleviated, but it cannot prevent deterioration of the recording layer due to permeated moisture.Also, SiO, SiO□, etc.
Laminating transparent dielectric layers such as MgF* and Aj2N can protect the recording layer from oxidation and hydrolysis, but these transparent dielectric materials have poor adhesion to the synthetic resin that serves as the substrate. It is difficult to use it as a protective layer for a substrate. Incidentally, in recent years, in order to modify the surface of a synthetic resin molded article, a technique of coating it with a thin film of an oxide such as silicon dioxide has been developed and put into practical use. Conventionally, various methods such as vacuum evaporation, sputtering, ion blating, and plasma CVD are known as methods for coating oxide films, etc., but these film forming methods require special equipment or However, there are problems in that it is difficult to form a coating on the surface of a large molded article or a molded article with a complicated shape, and the adhesion between the synthetic resin molded article and the coating is insufficient. Recently, instead of directly coating the surface of a synthetic resin molded body with a silicon dioxide film, a silicon-containing film with good adhesion is coated on the surface of the synthetic resin molded body in advance as a primary film (brimer), and then a silicon-containing film with good adhesion is applied on top of that. A method of creating a silicon dioxide film with good adhesion to the primary film has been proposed (Japanese Unexamined Patent Publication No. 6
1-12734). According to this method, since the brimer is cured to form a polymer having siloxane bonds, the adhesion between the silicon dioxide film and the brimer is improved, and a more durable coating can be obtained than in the conventional method. Moreover, since a coating and dipping method can be used, it is also applicable to large-sized or complicated-shaped synthetic resin molded bodies. However, in this method, almost no strong chemical bond is formed between the brimer and the synthetic resin molded body, so the adhesion between the synthetic resin molded body and the brimer is insufficient, and therefore the synthetic resin of the silicon dioxide film Adhesion to molded bodies is also not sufficient. Therefore, even if a conventionally known silicon dioxide coating method is simply applied to forming a protective layer of an optical information recording medium, it is difficult to form a coating with excellent adhesion to a substrate. [Problems to be Solved by the Invention] An object of the present invention is to improve moisture resistance, corrosion resistance, and scratch resistance.
Another object of the present invention is to provide an optical information recording medium that undergoes extremely little change in shape due to water absorption. Another object of the present invention is to provide a coated optical information recording medium having a silicon dioxide coating on the entire surface with excellent adhesion to a substrate. As a result of intensive research to overcome the problems of the prior art, the present inventors have discovered an optical information recording medium in which a recording layer, a dielectric layer and/or a protective layer are provided on a transparent substrate made of synthetic resin. , by providing a coating layer of a specific silyl peroxide compound on the surface of a transparent substrate, then forming a silicon dioxide coating on the entire surface of the optical information recording medium, and then heat-treating it under conditions that thermally decompose the silyl peroxide compound. , it is possible to form a silicon dioxide film with excellent adhesion to the substrate, and since the entire surface is covered with silicon dioxide film, moisture resistance, corrosion resistance, and scratch resistance are significantly improved, and water absorption is extremely low. It has been found that an optical information recording medium can be obtained. The present invention has been completed based on these findings.

[Means to solve the problem]

(According to the present invention, in an optical information recording medium in which a recording layer, a dielectric layer and/or a protective layer are provided on a transparent substrate made of synthetic resin, the following We-M formula (1
) A coating layer of a silyl peroxide compound shown in ) is provided, a silicon dioxide film is then formed on the entire surface of the optical information recording medium, and then a heat treatment is performed under conditions in which the silyl peroxide compound is thermally decomposed. A silicon dioxide-coated optical information recording medium and a method for manufacturing the same are provided. R, I, 5t(OOR'), 1(1) (in the formula, R may be the same or different from each other (, a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group, a methacryloxy group, an epoxy group, It represents an amino group, a mercapto group, an organic group having fluorine, or an organic group having chlorine, R' may be the same or different from each other, and represents an alkyl group, an acyl group, or an arylalkyl group, and n is 1 to 4. Each component of the present invention will be explained below. (Optical information recording medium) The optical information recording medium used in the present invention has a recording layer, a dielectric layer and/or a transparent substrate made of synthetic resin on a transparent substrate. Or, it is an optical information recording medium with a multilayer structure provided with a protective layer.The synthetic resin used as the material for the substrate includes polycarbonate resin, acrylic resin, epoxy resin, etc. It is not particularly limited as long as it is a synthetic resin with a high temperature.As the recording layer, TbFeCo, GdFe, TbCo,
DyFe, NdDyFeCo, TbFe, GdFeB1
．． Any conventionally known recording film such as a recording film made of GdTbFe or the like, or a film made of a phase change recording material or a dye-based recording material can be used. The material of the dielectric layer and/or protective film is 5in.
2. Dielectrics that form SL-based transparent layers, such as SiN++, SiA ON, and SiAβN, can be preferably used. The laminated structure of the optical information recording medium used in the present invention is as follows:
Typical examples include dielectric layer/recording layer/protective layer or substrate/recording layer/protective layer. In addition, it is not only possible to use a single-layer optical information recording medium (i.e., two optical information recording media each having a recording layer, a dielectric layer, and/or a protective layer formed on a transparent substrate made of synthetic resin), but also a recording layer with an adhesive layer between them. It may have a structure in which the side surfaces are pasted together, for example, a structure such as substrate/dielectric layer/recording layer/protective layer/adhesion H/protective layer/recording layer/dielectric layer/substrate. Such a laminated structure has fewer problems of warping. (Silyl Peroxide Compound) The silyl peroxide compound used in the present invention is a compound having a chemical structure represented by the following general formula (I). R,nS i (OOR'),, (I)(
In the formula, R may be the same or different from each other and may be a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group, a methacryloxy group, an epoxy group, an amino group, a mercapto group, an organic group having fluorine, or an organic group having chlorine. (R' may be the same or different from each other and represent an alkyl group, an acyl group, or an arylalkyl group, and n represents an integer of 1 to 4) Specific examples of silyl peroxide compounds include vinyl tris (t-butylperoxy)silane, vinyltris(cumemberoxy)silane, vinyltris(acetylperoxy)silane, vinyltris(benzoylperoxy)silane, vinyltris(lauroylperoxy)silane, γ-glycidoxyprobyltris( t-Butylperoxy) silane, γ-glycidoxyprobyl tris(cumemberoxy) silane, γ-glycidoxyprobyl tris(cumemberoxy) silane, γ-glycidoxyprobyl tris(acetylperoxy) ) silane, γ-glycidoxypropyltris(benzoylperoxy)silane, γ-glycidoxypropyltris(lauroylperoxy)silane, Y-methacryloxypropyltris(t-butylperoxy)silane, γ- Methacryloxypropyltris (cumene oxygen) silane, γ-methacryloxypropyltris (acetylperoxy) silane, γ-methacryloxypropyltris (benzoylperoxy) silane, γ-methacryloxypropyltris (lauroylperoxysilane) etc. can be mentioned. (Coating method) The coated optical information recording medium of the present invention is an optical information recording medium that includes a coating layer of the silyl peroxide compound after coating the synthetic resin substrate with the silyl peroxide compound (first step). It is manufactured by a coating method consisting of essentially three steps: forming a silicon dioxide film on the entire surface (second step) and then heat-treating (third step). (1) First step In the present invention using silyl peroxide A, a silyl peroxide compound is used as a brimer. First, one or more silyl peroxide compounds are dissolved in an organic solvent such as toluene, hexane, methyl ethyl ketone, methyl isobutyl ketone, heptane, ethyl acetate, butyl acetate, acetone, cyclohexanone, etc. to create a brimer solution. . The concentration of the silyl peroxide compound can be determined as appropriate, but from the viewpoint of ease of solution preparation and coating work, and from the viewpoint of obtaining a single layer of brimer with a desired thickness, a range of 1 to 30% by weight is usually preferred. This brimer solution is applied to a synthetic resin substrate by a spin-coating method, a dipping method, a spraying method, etc., and then the solvent is removed. When the optical information recording medium has a single-plate structure, it is preferable to apply the coating onto the synthetic resin substrate by a spin code method.The solvent is removed within a temperature range in which the silyl peroxide compound does not decompose thermally.Specifically, , air dry at room temperature for about 1 to 2 hours, or heat to about 60℃ and dry for 1 to 5 hours.
A method of drying for about a minute is preferred. ■Second step 2 Methods for forming a silicon dioxide film on the entire surface of the optical information recording medium including the silicon silyl peroxide compound coating layer include CVD method using silane gas and sputtering using a quartz plate as a target. method, dipping method using an organic solvent of an organosilicon compound, and precipitation method in which silicon oxide is immersed in a supersaturated hydrofluorosilicic acid solution to deposit a silicon oxide film. Among these, the precipitation method is preferred because it is easy to work with and can form a uniform film. As for this precipitation method, a known method disclosed in detail in JP-A-61-12734 can be applied. A supersaturated hydrofluorosilicic acid solution of silicon dioxide is made by dissolving silicon dioxide (silica gel, aerosil, silica glass, other silicon dioxide-containing materials, etc.) in a hydrosilicic acid solution, and then using water or a reagent (boric acid, Aluminum chloride, etc.) is added to create a supersaturated state of silicon dioxide. An optical information recording medium coated with a silyl peroxide compound may be brought into contact with this treatment liquid. The contact may be carried out by immersing the optical information recording medium in the processing liquid or by allowing the processing liquid to flow down onto its surface, but the immersion method is preferable in order to form a uniform coating. The concentration of hydrofluorosilicic acid in the treatment solution is 1 to 2 mol/β
It is preferable to saturate silicon dioxide in an aqueous solution of hydrofluorosilicic acid with a concentration of more than 2 mol/flood, and then dilute with water to obtain 1
A concentration of ~2 mol/β is desirable because the film formation rate is fast and coating can be carried out efficiently. In order to efficiently obtain a homogeneous film, it is preferable to continuously add and mix the boric acid aqueous solution while the optical information recording medium is immersed in the treatment liquid, and to circulate the treatment liquid and filter it with a filter. When silica gel is used as a source of silicon dioxide, a filter with a pore size of 1.5 μm or less is preferable, and when silica glass or the like is used, a filter with a pore size of 10 μm or less is preferable. In addition, when putting the processing liquid into an immersion tank and bringing it into contact with the optical information recording medium, it is important to ensure that the processing liquid flows in a laminar flow over the surface of the optical information recording medium during immersion. Preferable for forming a homogeneous film. The thickness of the silicon dioxide film can be determined as appropriate depending on the purpose of use, but usually, the purpose of surface modification can be achieved with about several 100 to several 1,000 coats. ■ Third step 1 Place 1 In the present invention, after forming the silicon dioxide film,
Perform heat treatment. Through this heat treatment, the silyl peroxide compound is decomposed to generate free radicals, and the action of these free radicals causes chemical bonds to form, thereby firmly adhering the surface of the synthetic resin substrate and the silicon dioxide film. The heat treatment temperature and time can be determined depending on the heat distortion temperature of the synthetic resin used for the substrate and the half-life of the silyl peroxide compound. For example, when using polycarbonate resin, polyacrylate resin, etc., heat treatment may be performed at 90 to 120°C for 1 to 2 hours. Generally, heat treatment at about 100° C. for 1 to 2 hours is sufficient. As a method of heat treatment, heating in a hot air dryer is preferred because of ease of operation. [Function] In the conventional brimer treatment using a silicon compound such as a silane coupling agent, no strong chemical bond is formed between the silicon compound and the surface of the synthetic resin substrate. On the other hand, in the brimer treatment using a silyl peroxide compound, free radicals are generated by thermal decomposition of the silyl peroxide compound by heat treatment, and a chemical reaction proceeds. It is presumed that the surface of the synthetic resin substrate and the silicon oxide film are chemically bonded via the brimer layer by a radical mechanism. As a result, a strong adhesive layer is formed at the interface between each layer. For example, it can be assumed that the following reaction occurs due to the radical mechanism. For example, when a silyl peroxide compound having an R,5iOOR' structure is thermally decomposed by heat treatment, R*
S i O radical and OR' radical are generated,
The R55iO radical bonds with the silicon atom of silicon dioxide. On the other hand, the .OR' radical extracts the hydrogen atom bonded to the carbon atom of the synthetic resin to become R'OH, generating radicals on the surface of the synthetic resin substrate. The radicals generated on the surface of the synthetic resin substrate bond with the silicon atoms of the R and SiO groups bonded to silicon dioxide. Of course, various other radical reaction mechanisms can be assumed, but in short, the single layer of silyl peroxide compound brimer generates free radicals as a result of heat treatment, and a chemical reaction progresses. It is presumed that the chemical bonds between the two are strongly bonded. Furthermore, when R is a vinyl group or a methacryloxy group, a polymerization crosslinking reaction occurs due to the generated radicals, so that a -N strong adhesive layer is formed. As described above, by the brimer treatment method of the present invention, it is possible to increase the bonding strength between the synthetic resin substrate and the silicon dioxide film, and obtain a silicon dioxide film-coated synthetic resin molded article with excellent adhesion.Furthermore, an optical information recording medium S provided on the recording layer of
The adhesion between the protective layer made of t-based dielectric material and the silicon dioxide film is also good. Since the optical information recording medium of the present invention has a structure in which its entire surface is coated with a silicon dioxide film with excellent adhesion, it has improved moisture resistance and corrosion resistance, extremely little change in shape due to water absorption, and excellent heat resistance. is also excellent. Furthermore, since it is coated with a transparent silicon dioxide film that has a high surface hardness, it has excellent scratch resistance and prevents signal deterioration and sensitivity loss. [Example J Hereinafter, the present invention will be specifically explained by giving examples and comparative examples, but the present invention is not limited only to these examples. In addition, the method of the accelerated deterioration test in Examples and Comparative Examples is as follows. Accelerated Deterioration Test> After holding a silicon dioxide-coated optical information recording medium (disk) for 3 weeks in a constant temperature and humidity machine at 65°C and 95% RH, C/N, maximum burst length of medium defects, Mechanical properties were evaluated. Above Z: Measured at rotation speed 1,800 rpm, frequency 3.7 MHz,
The writing laser power was approximately 5 mW, as a result of minimizing the secondary high frequency. The measurement position is the innermost circumference of the disk 2, and the results are the average values of the 100 track measurements. A signal was written using the burst byte (2.7) RLL modulation method, and comparisons were made before and after the accelerated deterioration test. The measurement position is the innermost circumference of the disk, and the results are for the loo track. 1 Pulse Go 1 After being kept in an atmosphere of 65° C. and 95% RH for 3 weeks, the radial inclination of the disk was measured. The measurement position was 45 mm in the radial direction from the center of the disk. Note that only the single-plate specification disc was evaluated. [Example 1] Optical disk substrate made of polycarbonate resin (diameter 1
30 mm, thickness 1.2 mm), a dielectric layer (SiA
An optical information recording medium having a structure in which 12ON)/recording layer (TbFeC)/protective layer (SiAρON) was provided in this order was produced. An n-hexane solution (concentration 1% by weight) of various silyl peroxide compounds shown in Table 1 was applied to the optical information recording medium using a spin coater, and then heated and dried with hot air at 60°C for 3 minutes. . The thickness of the silyl peroxide compound film after drying is approximately 4
There were 0 people. A silicon dioxide film was deposited on the entire surface of the optical information recording medium which had been subjected to the above-mentioned brimer treatment using a silicon dioxide film manufacturing apparatus similar to that shown in Japanese Patent Application Laid-Open No. 12734/1983. That is, the silicon dioxide coating manufacturing apparatus has a dipping tank consisting of an outer tank and an inner tank, and the space between the inner tank and the outer tank is filled with water. This water is heated with a heater to a temperature of 35° C., and is stirred with a stirrer to make the temperature distribution uniform. The inner tank consists of a front part, a middle part, and a rear part, and each part is filled with an aqueous solution of hydrofluorosilicic acid at a concentration of 2.0 mol/β in which silicon dioxide is dissolved and saturated using industrial silica gel powder as a source of silicon dioxide. It is filled with a reaction solution of 3I2 diluted to 20% using 3I2. At this point, the circulation pump was activated to discharge a certain amount of the reaction liquid from the rear of the inner tank, filter it with a filter, and start circulating the treated liquid back to the front of the inner tank. Thereafter, a 0.5 mol/Q boric acid aqueous solution was continuously added to the rear of the inner tank and maintained for 10 hours. In this state, the reaction solution became a treatment solution having an appropriate degree of silicon dioxide supersaturation. Here, the absolute removal rate of the filter was adjusted to 1.5 μm, and the processing solution circulation rate was adjusted to 240 mI2/min (since the total amount of processing solution was about 3β, the circulation rate was 8%/min). Then, the optical information recording medium subjected to the above-mentioned brimer treatment was immersed vertically into the middle of the inner tank, and the above-mentioned conditions (0.5 mol/2
0.2 mjl of boric acid aqueous solution! /min, 8%/min.
The mixture was circulated for 3 hours and filtered through a 1.5 μm filter. Thereafter, the optical information recording medium was taken out from the immersion tank and heated in a hot air dryer at 100"C for 1 hour to thermally decompose the silyl peroxide compound. As a result, the silyl peroxide compound was thermally decomposed. An optical information recording medium whose entire surface was coated with a film was obtained.The results of the accelerated deterioration test of each coated optical information recording medium obtained are shown in Table 1.For comparison, A silicon dioxide-coated optical information recording medium was obtained in the same manner as in Example 1, except that the brimer treatment was not performed, and an accelerated deterioration test was conducted in the same manner, and the results are also shown in Table 1. [Example 2] Implementation An optical information recording medium with a laminated structure was prepared by laminating the two optical disks of the single-plate specification prepared in Example 1 with an adhesive made of an acrylic photocurable resin on their recording layer sides. An n-hexane solution (1% by weight) of various silyl peroxide compounds shown in Table 2 was applied to the information recording medium using a spin coater, and the solution was heated and dried with hot air at 60° C. for 3 minutes. An optical information recording medium whose entire surface was coated with a silicon dioxide film was obtained by operating in the same manner as in Example 1. The thickness of the silicon dioxide film was approximately 950 mm.Acceleration of each coated optical information recording medium obtained The results of the deterioration test are shown in Table 2.For comparison, a silicon dioxide-coated optical information recording medium was obtained in the same manner as in Example 2, except that the brimer treatment with the silyl peroxide compound was not performed. An accelerated deterioration test was conducted on the optical information recording medium, and the results are also shown in Table 2. (See the margins below) [Effects of the Invention] According to the present invention, a silicon dioxide film with excellent adhesion can be formed on the entire surface of an optical information recording medium. Therefore, it is possible to provide an optical information recording medium that has improved moisture resistance, corrosion resistance, and scratch resistance, and whose shape changes due to water absorption are extremely small.Therefore, it is possible to provide an optical information recording medium that can be stored for a long time under a wide range of temperature and humidity conditions. In addition, in single-panel optical information recording media, improved moisture resistance prevents deterioration of mechanical properties such as warping due to water absorption.Furthermore, excellent scratch resistance prevents signal deterioration. There is no deterioration in sensitivity or sensitivity.

Claims (5)

[Claims] (1) In an optical information recording medium in which a recording layer, a dielectric layer and/or a protective layer are provided on a transparent substrate made of synthetic resin, the surface of the transparent substrate is coated with a silyl peroxide compound represented by the following general formula (I). 1. An optical information recording medium coated with silicon dioxide, characterized in that the layer is formed, a silicon dioxide film is then formed on the entire surface of the optical information recording medium, and the silyl peroxide compound is then heat-treated under conditions that thermally decompose the silyl peroxide compound. R_4_−_nSi(OOR')_n(I) (in the formula,
R may be the same or different from each other, and have a carbon number of 1
to 6 hydrocarbon groups, vinyl groups, methacryloxy groups, epoxy groups, amino groups, mercapto groups, fluorine-containing organic groups, or chlorine-containing organic groups, R' may be the same or different from each other, and R' may be the same or different from each other; group, acyl group or arylalkyl group, n represents an integer of 1 to 4) (2) An optical information recording medium is formed by attaching two optical information recording media each having a recording layer, a dielectric layer and/or a protective layer on a transparent substrate made of synthetic resin to the surface of the recording layer side via an adhesive layer. 2. The silicon dioxide-coated optical information recording medium according to claim 1, which has a structure in which two layers are bonded together. (3) In an optical information recording medium in which a recording layer, a dielectric layer and/or a protective layer are provided on a transparent substrate made of synthetic resin, the surface of the transparent substrate is coated with a silyl peroxide compound represented by the following general formula (I). A method for producing a silicon dioxide-coated optical information recording medium, which comprises providing a layer, then forming a silicon dioxide film on the entire surface of the optical information recording medium, and then heat-treating the silyl peroxide compound under conditions that thermally decompose the silyl peroxide compound. . R_4_−_nSi(OOR')_n(I) (in the formula,
R may be the same or different from each other, and have a carbon number of 1
to 6 hydrocarbon groups, vinyl groups, methacryloxy groups, epoxy groups, amino groups, mercapto groups, fluorine-containing organic groups, or chlorine-containing organic groups, R' may be the same or different from each other, and R' may be the same or different from each other; group, acyl group or arylalkyl group, n represents an integer of 1 to 4) (4) An optical information recording medium is formed by attaching two optical information recording media each having a recording layer, a dielectric layer and/or a protective layer on a transparent substrate made of synthetic resin to the surface of the recording layer side via an adhesive layer. 4. The method for manufacturing a silicon dioxide-coated optical information recording medium according to claim 3, wherein the optical information recording medium is of a structure in which two layers are bonded together. (5) After providing a coating layer of a silyl peroxide compound on the surface of a transparent substrate, the optical information recording medium is immersed in a supersaturated hydrofluorosilicic acid solution of silicon dioxide to coat the entire surface of the optical information recording medium with silicon dioxide. The method for producing a silicon dioxide-coated optical information recording medium according to claim 3 or 4, wherein the silicon dioxide-coated optical information recording medium is precipitated.