CN1456591A - Color three-dimensional storage material for optical information storage and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of optical information storage materials and optical signal conversion, and in particular relates to a color three-dimensional storage material for optical information storage and a preparation method thereof. Dissolve the polymer in cyclohexanone or toluene to make a polymer solution with a concentration of 0.1g/ml; choose two or more photochromic materials with different sensitivity and uniformly dissolve in the polymer , the ratio between the photochromic materials is an equimolar ratio, the concentration of each photochromic material in the high molecular polymer is 0.3mmol/g respectively, and a colored three-dimensional storage material for optical information storage is prepared. The material of the invention can be used for organic photochromic three-dimensional discs, multi-wavelength sensors and optical signal converters. This color three-dimensional optical disc can increase storage capacity and storage density, and realize multi-level recording.

Description

Colored three-dimensional storage material for optical information storage and preparation method thereof

Technical field

The invention belongs to the technical field of optical information storage materials and optical signal conversion, and in particular relates to a color three-dimensional storage material for optical information storage and a preparation method thereof.

Background technique

Optical disk storage technology has the characteristics of high storage density, large capacity, multiple functions, and low cost. With the rapid development of human spiritual civilization and material civilization, people will have amazing requirements for the amount of information needed for production and life and the speed of information processing. The amount of information can only be represented by "mass", and the processing speed of information will go from the current microseconds to nanoseconds and ultra-fast picoseconds, or even femtoseconds.

In recent years, with the development of multimedia technology, higher requirements have been put forward for the capacity and speed of computer external memory. The first generation of multimedia technology that started in 1993 required only 600MB of external storage capacity and a data transmission rate of 1Mbps, while the third generation of multimedia technology that is expected to start in 2005 requires an external storage capacity of at least 20GB and a data transmission rate of at least 20Mbps. The current two-dimensional optical storage principle is based on a single wavelength, and a certain recording medium is irradiated with a certain wavelength of laser light, so that the recording micro-area changes, thereby realizing the storage of information. In this case, the information storage density is inversely proportional to the square of the writing wavelength. For a laser of λ=532nm, the storage capacity is 3.5×10 ⁸ bits/cm ² , while the theoretical maximum storage capacity of three-dimensional storage is 6.5× 10 ¹² bits/cm ² . The three-dimensional storage mechanism is to use two beams of light that completely overlap in time and space to record information in a three-dimensional (3-D) medium. In 1989, Rentzepis first proposed the concept of three-dimensional optical storage, and found that photochromic spiropyran can be used as a three-dimensional optical storage material (Parthenopoulos DA, Rentzepis PM, Science, 1989, 245, 844).

Existing storage materials include inorganic materials and organic dyes. Compared with inorganic materials, organic dyes greatly reduce the production cost of write-once digital discs. Inorganic materials include alloy films such as tellurium, bismuth, selenium, and selenium, submicron metal particles, As ₂ -S ₃ or As ₂ -Se ₃ amorphous films, antimony-selenium (Sb-Se) or bismuth-tellurium (Bi -Te) amorphous film, etc.; organic dyes can be divided into cyanines, phthalocyanines, quinones, metal complexes, and azo compounds according to their structures. The defect of inorganic materials is that it has a strong absorption of light of various wavelengths, and cannot meet the requirement of an original reflectivity higher than 70% at 780nm, so it cannot be compatible with CD-ROMs; secondly, inorganic materials also have Prolonged exposure to light is prone to cracks and oxidation. For organic dyes, since the relationship between the molecular structure of dyes and their functions has not been thoroughly studied, the choice of dyes largely depends on experiments. At present, the primary criterion for choosing dyes is to look at their absorption wavelength, which must It matches the laser wavelength of the semiconductor. Organic photochromic materials have a wide range of absorption wavelengths, compounds exist from 400-800nm, and they have good thermal stability and fatigue resistance.

At the beginning of the 21st century, the development direction of the optical disc storage field: first, the development of green, blue and ultraviolet wavelength lasers; second, the corresponding optical recording system, measurement, detection and standardization, and complete drives. The third is to develop new unconventional optical storage materials and technologies.

From the perspective of basic principles, the cutting-edge technologies for improving the storage density and speed of optical discs include: holographic storage, spectral hole burning, electron capture and photochromic, etc. Photochromic digital storage is a high-density, high-speed storage that may be used earlier. technology.

The digital storage technology based on photochromism is to store information through chemical changes under the action of photons. level), which can achieve ultra-high-speed storage; in addition, because this reaction is based on the molecular scale, it is theoretically possible to reduce the scale of a single information symbol to the molecular level, which is conducive to greatly improving the storage density of the medium and achieving ultra-high density storage. The average time required for an existing magneto-optical disk to be accessed once is on the order of milliseconds (10 ^-3 ). If photon storage is directly used, the speed is expected to increase to the order of nanoseconds (10 ^-8 ) or even picoseconds (10 ^-12 ) , so as to adapt to the processing speed of the current computer (about 10 ^-8 execution once).

Contents of Invention

One of the objects of the present invention is to provide a color three-dimensional storage material for optical information storage, so as to overcome the defect of small storage capacity of existing storage materials.

Another object of the present invention is to provide a method for preparing a colored three-dimensional storage material for optical information storage.

The principle of color three-dimensional storage is based on the interaction of multiple wavelengths and various photosensitive materials. The information recording principle of this color three-dimensional optical disc is shown in Figure 1.

The so-called color three-dimensional optical disk refers to the addition of frequency dimensionality on the basis of the original two-dimensional optical disk, that is, on the same recording point, only one information bit (bit) can be recorded originally, and the three-dimensional optical disk can use different information on the same recording point. Photochromic materials with photosensitive wavelengths to achieve multiple recordings. As shown in Figure 1. If laser beams of four different wavelengths can be integrated into the same optical head output, quadruple recording can be realized at one point.

The colored three-dimensional storage material for optical information storage of the present invention is composed of an organic photochromic material and a polymer, wherein the organic photochromic material is composed of any two or more organic photochromic materials with different sensitivities. The composition of the photochromic material, the ratio between the organic photochromic materials is an equimolar ratio; the concentration of each organic photochromic material in the high molecular polymer is 0.3mmol/g respectively.

The preparation method of the colored three-dimensional storage material for optical information storage of the present invention is:

Dissolve the polymer in cyclohexanone or toluene to form a polymer solution with a concentration of 0.1g/ml; any two or more organic photochromic materials with different sensitivities are uniformly dissolved in the polymer In this method, the ratio between the organic photochromic materials is an equimolar ratio, and the concentration of each organic photochromic material in the polymer is 0.3mmol/g, and a color three-dimensional storage material for optical information storage is prepared. .

Apply the color three-dimensional storage material evenly on the photochromic glass substrate with a silver reflective layer by the glue-spinning method or vacuum coating method, put it in a dark place, and the solvent will evaporate naturally to form a color three-dimensional storage disk. The recording and erasing of information can be achieved through structural reversible reactions. In Examples 2 and 3, the organic photochromic three-dimensional storage material is taken as an example for specific description and property determination.

The high molecular polymer is polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polyvinyl chloride (PVC) or polyamide.

The recording medium is several materials that have obvious absorption to the light of specific wavelengths. The recording medium used in the present invention is an organic photochromic material, which is a near-infrared (chromatic body ultraviolet-visible absorption at 760-800nm) sensitive material, For example, dicyano derivatives of pyrrole fulginic anhydride; red light (color forming body ultraviolet-visible absorption at 630-670nm) sensitive materials, such as pyrrole fulginic anhydride compounds; green light (color forming body ultraviolet absorption at 510-550nm) Sensitive materials, such as fulgimides or oxazole fulgide derivatives; blue light (chromophore UV-visible absorption at 420-460nm) sensitive materials, such as oxazole fulgide compounds or diaryl heterocyclic groups Vinyl compounds.

The color three-dimensional storage material of the present invention can be used for:

1. Organic photochromic three-dimensional disc

Dissolve several types of organic photochromic compounds in a solution containing high polymers such as polymethyl methacrylate, and prepare photochromic discs by the glue-spinning method. The photosensitive wavelengths of several types of compounds can be well matched with different wavelength lasers. After the light beam is integrated, the output of multiple wavelengths has matching specificity, so as to realize information recording. That is, a material can only be sensitive to a specific wavelength.

2. Multi-wavelength sensor and optical signal converter

This kind of organic photochromic sensitive material, each medium has its specific light-sensitive wavelength, and the photosensitive material can be coated on a suitable plastic sheet by spinning or spinning to make a photosensitive sensor, which can be used for the detection and protection of laser beams .

The organic photochromic compound used in the colored three-dimensional storage material of the present invention is:

1. Near-infrared (760-800nm) sensitive materials: dicyano derivatives of pyrrole fulginic anhydride

Synthesize according to the method of the patent application whose publication number is CN1158882A applied by Fan Meigong et al. The structure of the compound is as follows, wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ are alkyl, aryl or substituted aryl, etc., Me is methyl, CN is cyano

2. Red light (630~670nm) sensitive material: pyrrole fulginic anhydride compounds

It is synthesized by the patent method of 93108615.9 according to the application number of Fan Meigong et al. The structure of the compound is as follows, wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ are alkyl, aryl or substituted aryl, and Me is methyl

3. Green light (510~550nm) sensitive materials:

(1) Spermimide compounds

It is synthesized by the patent application method of 00132705.4 applied by Fan Meigong and others. The structure of the compound is as follows, wherein R ¹ and R ² are alkyl, allyl, aryl or substituted aryl, the alkyl is a C ₁ -C ₂₀ aliphatic chain, and Me is methyl

(2) Oxazole fulginic anhydride derivatives

The synthesis method is as follows: at room temperature, under the protection of nitrogen, 1 times the mole of sodium hydride is added to toluene, stirred for 5 minutes, and 4-acetyloxazole and isopropylidene substituted with R ¹ of the same molar number as sodium hydride are dissolved. The toluene solution of diethyl diacid was added dropwise to the above-mentioned sodium hydride suspension. When about 1/5 of the volume was added, a drop of absolute ethanol was added to initiate the reaction. After the addition was completed, it was stirred at room temperature for 3 days. The reactants were treated to obtain gelatinous half esters. The half ester and potassium hydroxide are completely dissolved in absolute ethanol at a molar ratio of 1:2 to 1:5, heated and refluxed for 5 to 10 hours, cooled, and treated to obtain the diacid. The dried diacid and equimolar dicyclohexylcarbodiimide (DCC) were dissolved in tetrahydrofuran, and stirred at room temperature for 7 to 11 hours in the dark. Separation through a silica gel column, chloroform:petroleum ether eluting ^with a volume ratio of 4:1～1:1, to obtain a light yellow solid compound, the structure of which is as follows, wherein R is methyl, ethyl, aryl or substituted aryl base, Me is methyl

4. Blue light (420~460nm) sensitive materials:

(1) Oxazole fulginic anhydride compounds

For the synthesis method, refer to Japanese Patent 4-128282 in 1992 and the patent application method of application number 00128274.3 filed by Fan Meigong et al. Wherein ^R is methyl, ethyl, aryl or substituted aryl, Me is methyl

(2) Diaryl heterocyclic vinyl compounds

It is synthesized by the patent application method of 00105493.7 applied by Fan Meigong and others. The structure of the compound is as follows, where He is 2-methylindolyl, methyl-substituted thienyl, methyl-substituted benzothienyl, methyl-substituted indolyl, or 1,3-dimethylindolyl

For the optical disc prepared with the three-dimensional material of the present invention, a driver integrating multiple wavelengths into an optical head can be used to write, read and erase information. Certain organic photochromic materials can absorb light of a certain wavelength And react chemically, it is not sensitive to light of other wavelengths. The recording layer contains multiple or multi-layer organic photochromic materials with different absorption bands, and the corresponding multiple wavelengths are used to realize writing and reading respectively, so as to realize multi-wavelength Multiple records. This method is reported in the patent application No. 00103232.1 filed by Tsinghua University and the title of the invention is "Digital Color Multi-Layer Multi-level Optical Disc Writing and Reading Method". Different laser wavelengths can record different data at the same recording point. Information. When the laser beam of the integrated multi-wavelength laser irradiates the recording medium, a certain wavelength is absorbed by a certain substance, and different information is recorded, thereby increasing the storage capacity.

Compared with the current optical disc, the storage density of the optical disc proposed by the present invention is increased by an order of magnitude.

The color three-dimensional disc prepared by the color three-dimensional storage material of the present invention has the following advantages:

a) Large storage capacity. For example, from the original monochrome to the current four-color, the amount of information will directly increase by 4 times on the original basis.

b) High storage density. If one of the media is written by a short-wave laser, such as 780nm to 400nm laser, the amount of information can be increased by about 6 times.

c) Multi-stage recording is realized. To achieve multiple recordings on one recording spot, for four dyes, four different information may be stored.

d) This kind of optical disk can be realized by preparing a new photosensitive storage layer with the commercialized disk base by the glue-spinning method.

Description of drawings

Figure 1. Schematic diagram of color 3D recording principle;

Fig. 2. 3-[(2-p-tolyl 5-methyl-) oxazole-4] ethylidene-4-isopropylidene-5-[2-p-tolyl-5-methyl of the embodiment 3 of the present invention Base-4 formyl] methylene-furan-2-ketone UV absorption spectrum;

—Absorption of open-loop body, ... absorption of closed-loop body

Specific implementation methods Example 1. Preparation of static test samples

Washing of silver-plated substrates: Soak in lotion for 2 hours, take it out and rinse it with tap water, put it into a beaker filled with washing solution and ultrasonically clean it for 20 minutes, then soak it in ethanol for 1 hour, wash it in distilled water, take it out, wipe it with lens tissue Dry.

Preparation of film-spinning solution: 5 g of polymethyl methacrylate (PMMA) was dissolved in 50 ml of cyclohexanone to prepare a polymer solution. Red light sensitive material (1-p-methoxyphenyl-2-methyl-5-phenyl-3-pyrrole (isopropylidene) succinic anhydride) (pyrrole fulginic anhydride), near infrared sensitive material (5- Dicyanomethylene-4-dimethylidene-3-[1-(1-p-methoxyphenyl-2-methyl-5-phenyl)-3-pyrrole]-ethylidene (isopropylidene) Tetrahydrofuranone-2) (a dicyano derivative of pyrrole fulginic anhydride) was dissolved in the above solution, and 0.03 mmol of each photochromic component was added to each 1 ml of the solution.

Preparation of the recording film: drop the above-mentioned film-spinning solution to the middle of the glass substrate, add 0.5ml dropwise to each glass substrate with a size of 12×38cm, rotate at 2000 rpm, and take the film-spinning time for 20 seconds. Solvent naturally volatilizes in the dark.

Example 2.

The cross-interference test of the two-layer storage material of 650nm (red light) and 780nm (near infrared) was carried out on the disk of Example 1. The 650nm written area and the unwritten area were respectively irradiated with 780nm light, and the changes of initial transmittance and final transmittance in the two areas were compared. 1 2 3 4 5 650 write area Initial transmittance 0.30 0.30 0.26 0.38 0.30 Final transmittance 0.74 0.71 0.69 0.71 0.71 650 unwritten area Initial transmittance 0.38 0.41 0.43 0.41 0.34 Final transmittance 0.69 0.74 0.74 0.74 0.71

After 5 tests, the average initial transmittance in the written area is 0.308, the average value in the unwritten area is 0.394, and the average final transmittance is 0.712 and 0.724, respectively. It can be seen from the above that the deviation of the initial transmittance is slightly larger, and the deviation of the final transmittance is small, but they are all within the error range. The same result was obtained when the written area and the unwritten area were irradiated with 650nm light for 780°. That is, writing to one material has little effect on the other. There is very little cross-interference between the two materials. It can be used as a three-dimensional optical information storage material. Embodiment 3. According to the method of embodiment 1, a static test disk is produced.

Washing of silver-plated substrates: Soak in lotion for 2 hours, take it out and rinse it with tap water, put it into a beaker filled with washing solution and ultrasonically clean it for 20 minutes, then soak it in ethanol for 1 hour, wash it in distilled water, take it out, wipe it with lens tissue Dry.

Preparation of film-spinning solution: 5 g of polymethyl methacrylate (PMMA) was dissolved in 50 ml of cyclohexanone to prepare a polymer solution. Will. Green light-sensitive materials (1,2-dimethyl-3-indole ethylidene (isopropylidene)-N-benzyl spermimide) (spermimides), red light-sensitive materials (1-p-methoxyphenyl-2-methyl-5-phenyl-3-pyrrole (isopropylidene) succinic anhydride) (pyrrole fulginic anhydride) and near infrared sensitive material (5-dicyanomethylene -4-Dimethylidene-3-[1-(1-p-methoxyphenyl-2-methyl-5-phenyl)-3-pyrrole]-ethylidene(isopropylidene)tetrahydrofuranone-2) (dicyano derivative of pyrrole fulginic anhydride) was dissolved in the above solution, and 0.03 mmol of each photochromic component was added to each 1 ml of the solution.

Preparation of the recording film: drop the above-mentioned film-spinning solution to the middle of the glass substrate, add 0.5ml dropwise to each glass substrate with a size of 12×38cm, rotate at 2000 rpm, and take the film-spinning time for 20 seconds. Solvent naturally volatilizes in the dark.

Example 4.

3-[(2-p-tolyl-5-methyl-)oxazole-4]ethylidene-4-isopropylidene-5-[2-p-tolyl 5-methyl-4-formyl]methylene- Synthesis of furan-2-one

At room temperature, under the protection of nitrogen, add 10ml toluene to 1.6g sodium hydride (60% dispersed in paraffin oil, 0.04mol), stir for 5 minutes, and dissolve 4.32g (0.02mol) of 5-methyl-2-p-tolyl -50ml toluene solution of 4-acetyloxazole and 4.28g (0.02mol) diethyl ethylene propylene succinate was added dropwise to the above-mentioned sodium hydride suspension. Stir at room temperature for 3 days. The reactants were poured into 100 g of crushed ice, the aqueous phase was separated, the organic phase was extracted with 2×30 ml of saturated sodium carbonate aqueous solution, the aqueous phases were combined, and back-extracted with 30 ml of toluene. The aqueous phase was acidified with 5N dilute hydrochloric acid to pH<1, extracted with 3×50ml toluene, and the organic phase was dried over anhydrous magnesium sulfate. Remove the desiccant by filtration, and remove toluene by rotary evaporation to obtain a colloidal half-ester. Add 5g of potassium hydroxide and 50ml of absolute ethanol to the half-ester, heat to reflux for 5 hours, cool, filter with suction, dissolve the precipitate in 15ml of water, and acidify with 5N hydrochloric acid. To PH<1, filter with suction to obtain solid diacid, and dry. The dried diacid and equimolar dicyclohexylcarbodiimide (DCC) were dissolved in tetrahydrofuran and stirred at room temperature for 7 hours in the dark. The precipitate was removed by filtration, the solvent was removed from the mother liquor, the silica gel column was separated, and the chloroform:petroleum ether was rinsed at a volume ratio of 4:1 to obtain a light yellow solid. MP = 126-127°C. ¹ H NMR: 1.56(s, 3H), 1.92(s, H), 2.10(s, 3H), 2.40(s, 3H), 2.44(s, 3H), 2.46(s, 3H), 2.70(s, 3H) ), 730(m, 4H), 7.95(m, 4H). See accompanying drawing 2 for ultraviolet absorption spectrum.

Claims (6)

1. one kind is used for the color three dimension storage medium that optical information is stored, it is characterized in that: described color three dimension storage medium is made up of organic photochromic material and high molecular polymer, wherein said organic photochromic material is made up of any two or more different responsive photochromic materials, and the ratio between the organic photochromic material such as is at a mol ratio; The concentration of each photochromic material in high molecular polymer is respectively 0.3mmol/g;

Described organic photochromic material be into the colour solid uv-absorbing the near infrared sensitive material of 760～800nm, become the colour solid uv-absorbing at the red light sensitiveness material of 630～670nm, become the colour solid uv-absorbing at the green light sensitive material of 510～550nm or become the sensitive to blue light material of colour solid uv-absorbing at 420～460nm.

2. material as claimed in claim 1 is characterized in that: described high molecular polymer is polymethylmethacrylate, polycarbonate, polystyrene, polyvinyl chloride or polymeric amide.

3. material as claimed in claim 1 is characterized in that: the dicyano derivatives quasi-compound that described near infrared sensitive material is pyrroles's fulgide; The red light sensitiveness material is pyrroles's fulgide compounds; The green light sensitive material is fulgenimide compounds or oxazole fulgide derivatives quasi-compound; The sensitive to blue light material is oxazole fulgide compounds or two aromatic heterocyclic ethylene compounds;

The structure of the dicyano derivatives quasi-compound of pyrroles's fulgide is:

R wherein ¹, R ², R ³, R ⁴, R ⁵Be alkyl, aryl or substituted aryl, Me is a methyl, and CN is a cyano group;

The structure of pyrroles's fulgide compounds is:

R wherein ¹, R ², R ³, R ⁴, R ⁵Be alkyl, aryl or substituted aryl, Me is a methyl;

The structure of fulgenimide compounds is:

R wherein ¹, R ²Be alkyl, allyl group, aryl or substituted aryl, described alkyl is C ₁-C ₂₀Aliphatic chain, Me is a methyl;

The structure of oxazole fulgide derivatives quasi-compound is:

R wherein ¹Be the aryl of methyl, ethyl, aryl or replacement, Me is a methyl;

The structure of oxazole fulgide compounds is:

R wherein ¹Be the aryl of methyl, ethyl, aryl or replacement, Me is a methyl;

The structure of two aromatic heterocyclic ethylene compounds is:

Wherein He is 2 methyl indole base, methyl substituted thienyl, methyl substituted benzothienyl, methyl substituted indyl or 1, the 3-dimethylated indolyl.

4. one kind as any described preparation method who is used for the color three dimension storage medium of optical information storage of claim 1-3, it is characterized in that: high molecular polymer is dissolved in pimelinketone or the toluene, is made into the macromolecular solution that concentration is 0.1g/ml; Appoint photochromic materials of getting two or more different sensitivities evenly to be dissolved in the high molecular polymer, mol ratios such as the ratio between the photochromic material is, the concentration of each photochromic material in high molecular polymer is respectively 0.3mmol/g, prepares the color three dimension storage medium that is used for the optical information storage;

Described organic photochromic material be into the colour solid uv-absorbing the near infrared sensitive material of 760～800nm, become the colour solid uv-absorbing at the red light sensitiveness material of 630～670nm, become the colour solid uv-absorbing at the green light sensitive material of 510～550nm or become the sensitive to blue light material of colour solid uv-absorbing at 420～460nm.

5. method as claimed in claim 4 is characterized in that: described high molecular polymer is polymethylmethacrylate, polycarbonate, polystyrene, polyvinyl chloride or polymeric amide.

6. method as claimed in claim 4 is characterized in that: the dicyano derivatives quasi-compound that described near infrared sensitive material is pyrroles's fulgide; The red light sensitiveness material is pyrroles's fulgide compounds; The green light sensitive material is fulgenimide compounds or oxazole fulgide derivatives quasi-compound; The sensitive to blue light material is oxazole fulgide compounds or two aromatic heterocyclic ethylene compounds;

The structure of the dicyano derivatives quasi-compound of pyrroles's fulgide is:

R wherein ¹, R ², R ³, R ⁴, R ⁵Be alkyl, aryl or substituted aryl, Me is a methyl, and CN is a cyano group;

The structure of pyrroles's fulgide compounds is:

R wherein ¹, R ², R ³, R ⁴, R ⁵Be alkyl, aryl or substituted aryl, Me is a methyl;

The structure of fulgenimide compounds is:

R wherein ¹, R ²Be alkyl, allyl group, aryl or substituted aryl, described alkyl is C ₁-C ₂₀Aliphatic chain, Me is a methyl;

The structure of oxazole fulgide derivatives quasi-compound is:

R wherein ¹Be the aryl of methyl, ethyl, aryl or replacement, Me is a methyl;

The structure of oxazole fulgide compounds is:

R wherein ¹Be the aryl of methyl, ethyl, aryl or replacement, Me is a methyl;

The structure of two aromatic heterocyclic ethylene compounds is:

Wherein He is 2 methyl indole base, methyl substituted thienyl, methyl substituted benzothienyl, methyl substituted indyl or 1, the 3-dimethylated indolyl.