JPH05109114A - Flexible information recording disk and production thereof - Google Patents

Abstract

PURPOSE:To obtain a substrate having high quality by using polyimide fluoride formed by converting a part or the whole of the univalent element bonding to C of the alkyl group, fenyl ring, etc., of polyamide acid to F or perfluoroalkyl group as a flexible substrate material. CONSTITUTION:The total polyimide fluoride is the constitution expressed by formula. In the formula, R1 and R2 consist of 1 to 3 pieces of benzene rings. These rings are coupled indirectly at R1 or directly and indirectly at R2 in the case of >=2 pieces. The hydrogen in this polyimide is all substd. with fluorine or perfluoroalkyl group. Tetracarboxylic acid and the acid anhydride, acid chloride and esterified matter as its deriv. are used for production of the polyimide fluoride. This polyimide fluoride is cast on a master disk with pregrooves and is then heated and is parted from the mold. A recording layer and a transparent protective film are superposed on a groove forming surface. This disk exhibits excellent quality in transparency, double refractiveness, low water absorptivity, heat resistance, flexibility, surface accuracy, and uniformity of film thicknesses.

Description

Detailed Description of the Invention

[0001]

The present invention relates to transparency, birefringence, low water absorption, heat resistance, flexibility, surface accuracy, and film thickness used for image files, document files, and file memories in computer systems. The present invention relates to a flexible information recording disk having excellent uniformity and a method for manufacturing the same.

[0002]

2. Description of the Related Art An optical disk storage system capable of writing and reading information by light and a magneto-optical disk storage system capable of writing and reading information by light and magnetism are used as a small-sized and large-capacity storage device having a high areal recording density. It has shown rapid development in recent years. These storage systems have characteristics such as large capacity, non-contact recording / reproduction, high-speed random access, and long life. For example, a typical example of the optical disk storage system is a thin film of an information recording medium on a transparent substrate. After forming a protective layer on the information recording medium, information is written and read by irradiating a laser beam with a diameter of several μm from the substrate side. On the other hand, there is a flexible information recording disk system that has been developed for future computer peripheral devices like the optical disk storage system. This method may be considered to replace the conventional floppy disk magnetic storage method with a storage method that uses light or a combination of light and magnetism, and uses an air-floating flexible type disk to reduce the substrate thickness of the disk. It is kept to several tens of μm. The flexible type disc structure and the recording / reproducing of information are basically the same as those of the optical disc, and the flexible substrate of this disc has a high degree of transparency, low birefringence, as in the case of the optical disc substrate. Properties such as low water absorption, heat resistance, flexibility, surface accuracy and film thickness uniformity are required. Conventionally, plastic materials such as polyethylene terephthalate and polycarbonate, which are easily formed into a film, have been used for flexible type disk substrates from the viewpoints of the surface accuracy of the substrate and the uniformity of the film thickness.

[0003]

When the above plastic material is used as a substrate constituting a flexible information recording disk, a thin film having a thickness of several tens of μm is formed by a film forming method such as an extrusion forming method or a calendar forming method. Since it is made into a film, the molding strain is increased due to its manufacturing constraints, and the plastic material has a large photoelastic constant, and thus has a large birefringence, and has the drawback that it cannot be used practically. There is. Also, it is difficult to ensure the uniformity of the film thickness. In order to solve this problem, even when a polycarbonate film is produced by a casting method which is advantageous in terms of film thickness accuracy and molding distortion, the polycarbonate is easily crystallized in the presence of a solvent, and therefore a flexible substrate having high transparency is used. Hard to get. Further, the formation of the information recording medium on the surface of the flexible substrate, usually, a method such as vapor deposition, sputtering is used, but in this case too, considerable heat is added to the flexible substrate,
Since the flexible substrate using the above-mentioned ordinary plastic material lacks heat resistance, it has a drawback that the flexible substrate is likely to be thermally deformed. On the other hand, it is necessary to form a pre-groove for tracking on the flexible substrate surface of the flexible information recording disk. However, also in the formation of this pre-groove, restrictions on the flexible substrate material and the manufacturing method become a big problem. ing. In the case of an optical disk substrate or a magneto-optical disk substrate, the 2P method,
Although pregrooves can be formed by the injection method or the like, in the case of a flexible substrate for a flexible information recording disk, the above-mentioned pregroove forming method cannot be adopted because of its thin film and low strength reliability. In view of the above problems, the present invention is excellent in transparency, birefringence, low water absorption, heat resistance, flexibility, surface accuracy and film thickness uniformity, and it is easy to form a pregroove for tracking. An object of the present invention is to provide a flexible information recording disk and a method for manufacturing the same.

[0004]

SUMMARY OF THE INVENTION The present invention will be outlined. The first invention of the present invention relates to a flexible information recording disk, which is represented by the following general formula (Formula 1):

[Chemical 1] [Wherein R ₁ is the following formula (Formula 2):

[Chemical 2] R ₂ is a group represented by the following formula (Formula 3):

[Chemical 3] Wherein Rf is fluorine or a perfluoroalkyl group, and X is the following formula (Formula 4):

[Chemical 4] (Wherein Rf ′ is a perfluoroalkylene group, and n is a number of 1 to 10) and a fluorinated polyimide containing a repeating unit represented by the formula: A film having as a main component, a tracking pre-groove formed on one surface of the film, an information recording layer provided on the pre-groove forming surface of the film with pre-groove, and the information recording layer so as to cover the information recording layer. It has a formed optically transparent protective layer. A second invention of the present invention relates to a method for manufacturing a flexible information recording disk, which is represented by the following general formula (Formula 5):

[Chemical 5] Tetracarboxylic acids represented by [wherein R ₁ is the general formula (Formula 1) in the same meaning as R _1], or an acid component mainly composed of a derivative represented by the following general formula (Formula 6):

Embedded image H ₂ N-R ₂ -NH _2-diamine was reacted with a diamine component mainly comprising represented by [wherein R ₂ is Formula 1 in the same meaning as R ₂ in] , The following general formula (Formula 7):

[Chemical 7] [R ₁ and R ₂ wherein R ₁ and R ₂ are the general formula (Formula 1)
Synonymous with] a step of producing a fluorinated polyamic acid having a polyamic acid containing a repeating unit as a main component, and flowing the solution of the fluorinated polyamic acid on the surface of a master with a pregroove for tracking. A step of producing a pre-grooved fluorinated polyimide film by releasing and releasing, followed by heat treatment, a step of providing an information recording layer on the pre-groove forming surface of the pre-grooved fluorinated polyimide film, and covering the information recording layer Thus, each step of providing an optically transparent protective layer.
A third invention of the present invention relates to another method for manufacturing a flexible information recording disk, comprising the step of manufacturing a fluorinated polyamic acid by the method of the second invention,
After the heat treatment of the fluorinated polyamic acid, a step of polyimidizing, dissolving the fluorinated polyimide in an organic solvent,
Step of applying to the surface of the master with pre-groove for tracking, after removing the solvent by evaporation, a step of releasing from the surface of the master with pre-groove for tracking to produce a fluorinated polyimide film with pre-groove, with the pre-groove It is characterized by comprising each step of providing an information recording layer on the pregroove forming surface of the fluorinated polyimide film, and providing an optically transparent protective layer so as to cover the information recording layer.

The inventors of the present invention have earnestly conducted various studies on flexible substrates to achieve the above object, and as a result, have found that fluorinated polyimides have high transparency, low birefringence,
It was found that it has low water absorption and heat resistance.

The fluorinated polyimide used as the flexible substrate material in the present invention is one in which a part or all of the monovalent element bonded to carbon such as an alkyl group of polyamic acid or a phenyl ring is a fluorine or perfluoroalkyl group. is there.

The information recording layer is not limited to recording systems such as thermal recording and thermomagnetic recording, and includes information recording layers for all recording systems, and the flexible information recording disk of the present invention. Is applicable to all flexible type recording methods.

In the fluorinated polyimide of the present invention, part or all of the monovalent element bonded to carbon such as an alkyl group or a phenyl ring is fluorine or perfluoroalkyl group, and a C-H bond is preferably contained in the repeating unit. With the structure that does not allow, vibration absorption based on the C—H bond, which is the largest cause of light loss in the near infrared region, can be eliminated.

The tetracarboxylic acid or its derivative used for producing the fluorinated polyimide of the present invention includes:
Bond to carbon such as alkyl group and phenyl ring in the molecule 1
Any one may be used as long as part or all of the valent element is fluorine or a perfluoroalkyl group.
Acid anhydrides as tetracarboxylic acids and their derivatives,
Examples of acid chlorides, ester compounds and the like include the following. Examples of the tetracarboxylic acid are 1,4-difluoropyromellitic acid, 1-trifluoromethyl-4-fluoropyromellitic acid, 1,4-di (trifluoromethyl) pyromellitic acid, and 1,4. -Di (pentafluoroethyl) pyromellitic acid, hexafluoro-3,3 ', 4,4'-biphenyltetracarboxylic acid, hexafluoro-3,3', 4,4'-benzophenonetetracarboxylic acid, 2,2 -Bis (3,4-dicarboxytrifluorophenyl) hexafluoropropane, 1,3-bis (3,4-dicarboxytrifluorophenyl) hexafluoropropane, 1,4-bis (3,4-dicarboxytri) Fluorophenoxy) tetrafluorobenzene, hexafluoro-3,3 ′ (or 4,4 ′) oxybisphthalic acid, etc. It is. Among these, 1,4-di (trifluoromethyl) pyromellitic dianhydride, which is a fluorine-containing dianhydride in which a fluoroalkyl group is introduced into the benzene ring of pyromellitic dianhydride, 1,
A method for producing 4-di (pentafluoroethyl) pyromellitic dianhydride and the like is described in Japanese Patent Application No. 63-165056.

Examples of the diamine which can be used in the present invention include an alkyl group excluding an amino group in the molecule, a part or all of a monovalent element bonded to carbon such as a phenyl ring, or fluorine or perfluoroalkyl. Any group may be used as long as it is based on 3,4,5,6-tetrafluoro-1,2-phenylenediamine, 2,4,5,5.
6-tetrafluoro-1,3-phenylenediamine,
2,3,5,6-tetrafluoro-1,4-phenylenediamine, 4,4′-diaminooctafluorobiphenyl, bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether, bis ( 2,3,5,6-tetrafluoro-4-aminophenyl) sulfone, hexafluoro-2,2'-bis (trifluoromethyl) -4,
4'-diaminobiphenyl and the like.

The method for producing the fluorinated polyamic acid, which is the fluorinated polyimide precursor used in the present invention, may be the same as the production conditions for ordinary polyamic acid, and generally, N-methyl-2-pyrrolidone, N, The reaction is carried out in a polar organic solvent such as N-dimethylacetamide or N, N-dimethylformamide. In the present invention, not only a diamine or a tetracarboxylic acid component is used as a single compound, but a plurality of diamine and tetracarboxylic acid components may be mixed and used. In that case, the total number of moles of the plural or single diamine components and the total number of moles of the plural or single tetracarboxylic acid components are equal or nearly equal. In the polymerization solution of the polyamic acid or the like, the concentration of the solution is 5 to 40% by weight (preferably 10 to 25% by weight), and the rotational viscosity (25 ° C.) of the polymer solution is 50 to 5000 poise. Is preferred.

The master disc with pregrooves for tracking used in the present invention can be easily obtained by the ordinary master disc manufacturing process exemplified in Japanese Patent Application No. 59-20732.

As described above, when a flexible information recording disk using the flexible substrate with a pre-groove made of the above-mentioned fluorinated polyimide resin is manufactured, the high transparency, low birefringence and low characteristic of the fluorinated polyimide resin are produced. It is possible to obtain a flexible information recording disk excellent in flexibility, surface accuracy, and uniformity of film thickness in addition to water absorption and heat resistance. Furthermore, by adopting a normal casting method using a pre-groove forming master as a base or a solvent evaporation method, a pre-groove can be formed on the surface of a flexible substrate. By combining these technologies, flexible information recording can be performed. A disc can be realized.

[0014]

The above fluorinated polyimide resin is transparent in the near infrared region and has low birefringence (main refractive index difference 1 × 1).
0 ^-3), low water absorption (saturated water absorption below 0.2%), has heat resistance and is very suitable as a flexible substrate material for a flexible information recording disc. Furthermore, since the fluorinated polyimide resin of the present invention can be easily made into a flexible substrate by casting and heating fluorinated polyamic acid, if a master with pregroove is used as a casting mold, surface accuracy and film thickness are uniform. A flexible substrate with a pre-groove having excellent properties can be easily obtained. Further, since the fluorinated polyimide resin has heat resistance, when the information recording medium is formed on the surface of the flexible substrate by vapor deposition, sputtering or the like, the flexible substrate is not thermally deformed.

[0015]

EXAMPLES The flexible information recording disk of the present invention will be described in detail below with reference to specific examples. In the examples of the present invention, a flexible information recording disk using a perfluorinated polyimide resin is illustrated, but the invention is not limited to this, and a flexible information recording disk using a partially fluorinated polyimide resin is used. Good. In addition, in the following examples, imidation was confirmed by characteristic absorption by symmetric and asymmetric stretching vibration of carbonyl group in infrared absorption spectrum, and light transmittance was measured by measuring ultraviolet-visible absorption spectrum.

Example 1 1,4-bis (3,4-dicarboxytrifluorophenoxy) tetrafluorobenzene dianhydride having the following structural formula (Formula 8) in an Erlenmeyer flask:

[Chemical 8] 11.644 g (20.0 mmol) and 2,4,5,6-tetrafluoro- represented by the following structural formula (Formula 9)
1,3-phenylenediamine:

[Chemical 9] 3.602 g (20.0 mmol) and 86 g of N, N-dimethylacetamide (DMAc) were added. This solution was stirred at room temperature for 3 days in a nitrogen atmosphere to obtain a DMAc solution of polyamic acid. This solution was cast on a master with pregrooves for tracking kept at high temperature for imidization, and the solidified film was peeled off from the master to give a fluorinated polyimide flexible substrate with pregrooves having a thickness of 80 μm. Obtained. When the infrared absorption spectrum of this perfluorinated polyimide film was measured, the absorption peculiar to the imide group appeared at 1790 cm ^-1, and it was confirmed that the imidization proceeded completely. When the light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, as shown in FIG. 1, no light absorption other than water absorption was observed. In addition, Comparative Example 1 shown below
It was smaller than the conventional polyimide film prepared in. That is, in FIG. 1, the solid line is a graph showing the wavelength dependence of the light absorbance in the perfluorinated polyimide of Example 1, and the broken line is the polyimide of Comparative Example 1. In FIG. 1, the vertical axis represents the absorbance and the horizontal axis represents the wavelength (μm).

The perfluorinated polyimide flexible substrate with the pregroove thus produced has an outer diameter of 130 mm.
After being processed into a shape of φ and an inner diameter of 15 mmφ, a CS ₂ —Te plasma polymerized film which can be changed by light energy, for example, was applied to the pre-groove forming surface of the flexible substrate with a thickness of 300 A as an information recording layer. Further, a thickness of silicon oxide of 10 is formed on the information recording layer by sputtering.
A transparent protective layer having a thickness of μm was provided to prepare a flexible information recording disk as shown in FIG. That is, FIG. 2 is a diagram illustrating the configuration of the flexible information recording disk of the present invention. Here, 1 is a fluorinated polyimide flexible substrate with a pre-groove, 2 is an information recording layer, 3 is a transparent protective layer, and 4 is a flexible information recording disk. The flexible information recording disk 4 is placed on the turntable of the disk drive device, and the thickness of 1.2 mm is applied from above.
Recording was performed at an output of 4 mW and reproduction was performed at an output of 3 mW while the glass plate of 3 was pressure-bonded and rotated at 1800 rpm, and good recording and reproduction characteristics could be obtained.

Example 2 In an Erlenmeyer flask, 11.644 g (20.0 mmol) of 1,4-bis (3,4-dicarboxytrifluorophenoxy) tetrafluorobenzene dianhydride and the following structural formula (Formula 10) are shown. Bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether:

[Chemical 10] 6.883 g (20.0 mmol), and DMAc10
Then, 5 g was added, and a fluorinated polyimide flexible substrate with pregroove was molded in the same manner as in Example 1 below.
When the absorption spectrum of this flexible substrate was measured, no light absorption other than water absorption was found in the wavelength range of 0.8 to 1.7 μm. Further, it was smaller than the conventional polyimide flexible substrate manufactured in Comparative Example 1. Next, an information recording layer and a transparent protective layer were formed on the surface of the pregroove-formed fluorinated polyimide flexible substrate with pregrooves to obtain a flexible information recording disk. The flexible information recording disk manufactured in this manner showed good recording / reproducing characteristics as in Example 1.

Example 3 In an Erlenmeyer flask, 11.644 g (20.0 mmol) of 1,4-bis (3,4-dicarboxytrifluorophenoxy) tetrafluorobenzene dianhydride and the following structural formula (Formula 11) are shown. Bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfide:

[Chemical 11] 7.205 g (20.0 mmol), and DMAc10
7 g was added, and a fluorinated polyimide flexible substrate with pre-groove was molded in the same manner as in Example 1 below.
When the absorption spectrum of this flexible substrate was measured, no light absorption other than water absorption was found in the wavelength range of 0.8 to 1.7 μm. Further, it was smaller than the conventional polyimide flexible substrate manufactured in Comparative Example 1. Next, an information recording layer and a transparent protective layer were formed on the surface of the pregroove-formed fluorinated polyimide flexible substrate with pregrooves to obtain a flexible information recording disk. The flexible information recording disk manufactured in this manner showed good recording / reproducing characteristics as in Example 1.

Example 4 1,4-Erlenmeyer flasks having the following structural formula (Formula 12)
Difluoropyromellitic dianhydride:

[Chemical 12] 5.082 g (20.0 mmol) and 2,4,5,6,6
-Tetrafluoro-1,3-phenylenediamine 3.6
02 g (20.0 mmol) and 49 g of DMAc were added, and a fluorinated polyimide flexible substrate with a pre-groove was molded in the same manner as in Example 1 below. When the absorption spectrum of this flexible substrate was measured, no light absorption other than water absorption was found in the wavelength range of 0.8 to 1.7 μm. Further, it was smaller than the conventional polyimide flexible substrate manufactured in Comparative Example 1. Next, an information recording layer and a transparent protective layer were formed on the surface of the pregroove-formed fluorinated polyimide flexible substrate with pregrooves to obtain a flexible information recording disk.
The flexible information recording disk manufactured in this manner showed good recording / reproducing characteristics as in Example 1.

Example 5 In an Erlenmeyer flask, 5.082 g (20.0 mmol) of 1,4-difluoropyromellitic dianhydride and bis (2,2)
3,583,6-tetrafluoro-4-aminophenyl) ether 6.883 g (20.0 mmol), and DMA
Then, 68 g of c was added, and then a fluorinated polyimide flexible substrate with pregroove was molded in the same manner as in Example 1. When the absorption spectrum of this flexible substrate was measured, no light absorption other than water absorption was found in the wavelength range of 0.8 to 1.7 μm. Further, it was smaller than the conventional polyimide flexible substrate manufactured in Comparative Example 1. Next, an information recording layer and a transparent protective layer were formed on the surface of the pregroove-formed fluorinated polyimide flexible substrate with pregrooves to obtain a flexible information recording disk. The flexible information recording disk manufactured in this manner showed good recording / reproducing characteristics as in Example 1.

Example 6 In an Erlenmeyer flask, 5.082 g (20.0 mmol) of 1,4-difluoropyromellitic dianhydride and bis (2,2)
7.205 g (20.0 mmol) of 3,5,6-tetrafluoro-4-aminophenyl) sulfide and DM
Ac 70 g was added, and then a fluorinated polyimide flexible substrate with pregroove was molded in the same manner as in Example 1. When the absorption spectrum of this flexible substrate was measured, no light absorption other than water absorption was found in the wavelength range of 0.8 to 1.7 μm. Further, it was smaller than the conventional polyimide flexible substrate manufactured in Comparative Example 1. Next, an information recording layer and a transparent protective layer were formed on the surface of the pregroove-formed fluorinated polyimide flexible substrate with pregrooves to obtain a flexible information recording disk. The flexible information recording disk manufactured in this manner showed good recording / reproducing characteristics as in Example 1.

Example 7 The DMAc solution of the polyamic acid obtained in Example 1 was heated at 70 ° C. for 2 hours, 160 ° C. for 1 hour, 250 ° C. for 30 minutes, and 350 ° C.
Imidization was carried out under the condition of 1 ° C. for 1 hour. This imidization was 1790c as measured by infrared absorption spectrum as in Example 1.
Absorption peculiar to an imide group was not found in m ⁻¹ , and no light absorption other than water absorption was observed in the wavelength range of 0.8 to 1.7 μm in the measurement of light absorption. Then, the fluorinated polyimide thus produced is treated with a polar solvent such as DMAc.
Etc., then apply the solution to the surface of the master with pre-groove for tracking, remove the solvent by evaporation and release the film from the surface of the master with pre-groove for tracking to form a fluorinated polyimide film with pre-groove. Obtained.
After that, an information recording layer and a protective layer were provided on the pre-groove forming surface in the same manner as in the above example to obtain a flexible information recording disk. The flexible information recording disk manufactured in this manner showed good recording and reproducing characteristics as in Example 1.

Comparative Example 1 In an Erlenmeyer flask, 2,2 having the following structural formula (Formula 13)
-Bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride:

[Chemical 13] 8.885 g (20.0 mmol) and 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl represented by the following structural formula (Formula 14):

[Chemical 14] 6.405 g (20.0 mmol), and DMAc87
Then, a polyimide flexible substrate with a pre-groove was molded in the same manner as in Example 1 below. When the absorption of light in the wavelength range of 0.8 to 1.7 μm of this flexible substrate was measured, as shown by the broken line in FIG.
The absorption of the stretching vibration of the C—H bond by the third overtone is around 1 μm, and the absorption of the harmonic of the stretching vibration of the C—H bond and the combined sound of the bending vibration is around 1.45 μm.
In the vicinity of m, absorption by the second harmonic of the stretching vibration of the C—H bond appeared. From these results, it became clear that the perfluorinated polyimide of the present invention has an extremely small light transmission loss rate in the near infrared region as compared with the conventional one. Next, an information recording layer and a transparent protective layer were formed on the pre-groove forming surface of the polyimide flexible substrate with pre-groove to obtain a flexible information recording disk. The recording / reproducing characteristics of the flexible information recording disk manufactured in this manner were extremely poor.

[0025]

As described above, according to the flexible information recording disk of the present invention using the fluorinated polyimide as the substrate material, the fluorinated polyimide flexible substrate with the pre-groove is extremely transparent, low in birefringence and low in refractive index. Excellent in water absorption, heat resistance, flexibility, surface accuracy, and uniformity of film thickness, so it is good for flexible information recording disks in which an information recording layer and a transparent protective layer are formed on the pre-groove forming surface of the flexible substrate. It is possible to obtain excellent recording / reproducing characteristics.

[Brief description of drawings]

FIG. 1 is a graph showing the wavelength dependence of light absorbance in the perfluorinated polyimide of Example 1 and in the polyimide of Comparative Example 1, respectively.

FIG. 2 is a diagram illustrating a configuration of a flexible information recording disc of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fluorinated polyimide flexible substrate with pre-groove, 2 ... Information recording layer, 3 ... Transparent protective layer, 4 ... Flexible information recording disk

[Procedure amendment]

[Submission date] October 8, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shigekuni Sasaki 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. The following general formula (Formula 1): [Wherein R ₁ is the following formula (Formula 2): R ₂ is a group represented by the following formula (Formula 3): Wherein Rf is fluorine or a perfluoroalkyl group, and X is the following formula (Formula 4): (Wherein Rf ′ is a perfluoroalkylene group, and n is a number of 1 to 10) and a fluorinated polyimide containing a repeating unit represented by the formula: A film having as a main component, a tracking pre-groove formed on one surface of the film, an information recording layer provided on the pre-groove forming surface of the film with pre-groove, and the information recording layer so as to cover the information recording layer. A flexible information recording disk having an optically transparent protective layer formed. 2. The following general formula (Formula 5): Tetracarboxylic acids represented by [wherein R ₁ is the general formula (Formula 1) in the same meaning as R _1], or an acid component mainly composed of a derivative represented by the following general formula (Formula 6): [ of 6] H ₂ N-R ₂ -NH ₂ the diamine represented by [wherein R ₂ is the general formula (formula 1) R ₂ as synonymous in] by reacting a diamine component composed mainly, The following general formula (Formula 7): [R ₁ and R ₂ wherein R ₁ and R ₂ are the general formula (Formula 1)
Synonymous with] a step of producing a fluorinated polyamic acid containing a polyamic acid containing a repeating unit as a main constituent, and flowing the fluorinated polyamic acid in a solution form on the surface of a master with a pregroove for tracking. A step of producing a pre-grooved fluorinated polyimide film by releasing and releasing, followed by heat treatment, a step of providing an information recording layer on the pre-groove forming surface of the pre-grooved fluorinated polyimide film, and covering the information recording layer A method of manufacturing a flexible information recording disk, comprising the steps of: providing an optically transparent protective layer. 3. A step of producing a fluorinated polyamic acid by the method according to claim 2, a step of subjecting the fluorinated polyamic acid to heat treatment and then polyimidization, and dissolving the fluorinated polyimide in an organic solvent for tracking. Step of applying to the surface of the master with pre-groove, after removing the solvent by evaporation, a step of releasing from the surface of the master with pre-groove for tracking to produce a fluorinated polyimide film with pre-groove, the fluorination with pre-groove Manufacture of a flexible information recording disk characterized by comprising the steps of providing an information recording layer on the pre-groove forming surface of a polyimide film, and providing an optically transparent protective layer so as to cover the information recording layer. Method.