CN100495552C - Film material for erasable short wavelength optical memory and preparing method thereof - Google Patents

Abstract

This invention relates to a film material used in an erasable rewrite short wavelength light storage and its preparation method, which applies a suitable solvent to dissolve the K(TCNQ) in adaptive high polymers then coats it on a glass chip or a PC chip to manufacture a high polymer film containing K(TCNQ), the inverse photochromic spectrum and the light storage property of said film are studied. The film has two character absorption peaks at the wavelength of 365nm and 605nm and can be used in the erasable write optical storage disk of 650nm red light DV and 405nm short wavelength, the result tested by a 650nm static device shows the performance does not become serious after circulating a hundred times.

Description

A kind of membraneous material that is used for the erasable rewrite short wavelength optical storage and preparation method thereof

Technical field

The invention belongs to optical memory material and field of optical disc technology, be specifically related to a kind of erasable rewrite short wavelength optical storage membraneous material and preparation method thereof that is used for.

Technical background

Optical storage technology has extensively entered every science and technology, economic field and our daily life.But numerous scientific workers still constantly pursue higher storage density, bigger memory capacity.In pursuing high density, jumbo technology path, " short wavelength " route is that a kind of technical requirement is simple relatively, thereby the approach of most probable realization.Because limited by optical diffraction limit, the minimum diameter of laser beam spot is directly proportional with wavelength, shortens wavelength and can reduce beam spot size.Storage density in principle with (～1/ λ that square is inversely proportional to of wavelength ²).Adopt short wavelength laser can increase storage density greatly.

At present DVD adopt red (laser of λ=650nm), DVD-R with the dyestuff record but only record once, DVD-RW can record repeatedly and wipe hundreds ofly to 1,000 times, but disc adopts polynary phase-change material, complex manufacturing, price height.And owing to utilize " heat " effect of light, technology is more difficult when adopting short-wave laser (cold laser).

K (TCNQ) is by metallic potassium and organism TCNQ (7,7,8,8-tetracyanoquinodimethane) the metal organic charge transfevent complex of Gou Chenging, the Ag that has reported (TCNQ) similar [1,2],, thereby can be used as a kind of storage medium of short wavelength's high-density storage CD because it has the ability of reverse photochromism characteristic.And, owing to be to utilize " light " pattern of variable color mechanism but not " heat " pattern, to adopting short wavelength laser favourable.But as use the method for vacuum evaporation to prepare film because crystal grain big [3], so shot noise is also bigger; Vacuum Coating method cost height, film forming speed are slow in addition, also can't with the spin-coating method process compatible of the large-scale production CD of present employing.On the other hand, because K (TCNQ) is insoluble in common solvent, be the key of technology with the spin-coating method preparation technology requirement that adapts to recording sheet so study suitable system, also be difficult point.

List of references

[1]Robert?C.Hoffman?and?Richard?S.Potember；Applied?Optics?28?No.71417-1421(1989)

[2]Zhong-yi?Hua，Guo-Rong?Chen，Dian-Yong?Chen?and?Hua-Hua?Xu；IEEE?Transaction?onConsumer?Electronics?45/197(1999)

[3]Xiao-Liang?Mo，Guo-Rong?Chen，Qin-Jia?Chai，Zhi-Yong?Fan，Hua-Hua?Xu，Yan?Yao，JianYang，Hai-Hua?Gu，Zhong-Yi?Hua；Thin?Solid?Film?436?259-263(2003)

[4]L.R.Melby，R.J.Harder，W.R?Hertler，W.Mahler，R.E?Benson?and?W.E.Mochel；J.Am.Chem.Soc.Vol?84?3374-3387(1962)

Summary of the invention

The objective of the invention is to propose that a kind of cost is low, speed is fast and is applicable to erasable rewrite short wavelength optical storage membraneous material of spin coating proceeding and preparation method thereof.

TCNQ can form 3 electron-like conductivity type compounds [4].The first kind keeps characteristic and aromatic hydrocarbon, amine and the polyhydroxy phenol of its quinone to form crystalline π-complex compound (charge transfer type complex compound), contour resistivity (10 during this class complex compound has ³～10 ⁴Ohm cm) and very weak electron paramagnetic resonance absorb.Second compounds can be expressed as M with the molecular formula of simple salt ^N+(TCNQ ^-) _n, this compounds has high resistivity (10 when solid-state ⁴～10 ¹²Ohm cm) and weak electron paramagnetic resonance absorb.The 3rd compounds useful molecules formula M ^N+(TCNQ ^-) _n(TCNQ) expression, this compounds also contains the TCNQ of a neutrality, so have low especially resistivity (10 ^-2～10 ³Ohm cm) and variable electron paramagnetic resonance absorb.

That obtain usually with the reaction of metal iodide and TCNQ is M ^N+(TCNQ ^-) _nSo simple class salt compound.Utilize this reaction, we have prepared metal-TCNQ complex K (TCNQ).Because iodide are excessive greatly in the reaction, so the I that is generated by the TCNQ oxidation ₂With excessive I ^-Complexing becomes I ₃ ^-, its chemical reaction is

3KI+2TCNQ→2K(TCNQ)+K ⁺+I ₃ ^-。

The erasable rewrite short wavelength optical storage membraneous material that the present invention proposes is coated after being scattered in the ethyl cellulose by metal organic complex K (TCNQ) on the substrate and is prepared, and the weight ratio of ethyl cellulose and K (TCNQ) is 2:100-10:100.K is a metallic potassium, and TCNQ is 7,7,8,8-four cyano benzoquinones bismethane.

The preparation method of above-mentioned optical storage membraneous material is as follows: 10Amg K (TCNQ) is dissolved in (2-6) Aml acetonitrile (CH ₃CN) and (2-6) Aml DMF (N, dinethylformamide, HCON (CH ₃) ₂) mixed solution in, obtain K (TCNQ)-acetonitrile-DMF mixed solution; Treat to dissolve fully the back and add the ethyl cellulose of corresponding part by weight (i.e. (0.2-1) Amg) and (3-8) Aml methylene chloride (CH ₂Cl ₂) solution, sonic oscillation 10-40 minute; Then K (TCNQ) Polymer Solution is spun on the substrate, the infrared lamp oven dry gets final product.Here A is a scale-up factor.

Among the above-mentioned preparation method, substrate can adopt glass substrate, also can adopt PC (polycarbonate) substrate.When adopting the PC substrate, also be added with (1-2) Aml cellosolve in the solution of ethyl cellulose and methylene chloride, add then in K (TCNQ)-acetonitrile-DMF mixed solution.Here A is a scale-up factor.

Be spun on respectively on glass substrate and the PC substrate after K (TCNQ) is dissolved in macromolecule, the film that makes is surveyed its transmitted spectrum (see figure 1) at 330-900nm wave band.As shown in the figure, the macromolecule membrane that contains K (TCNQ) respectively has an absorption peak near 365nm and 605nm in this wave band, and this two peak is TCNQ ^-Electronic transition produces.

Fig. 2 (a) and (b), (c), (d), (e) and (f) be respectively TCNQ, K (TCNQ), contain K (TCNQ) macromolecule membrane and do not contain the infrared spectrogram of the macromolecule membrane of K (TCNQ), wherein (e), (f) have added cellosolve in preparation process.Comparison diagram 2 (a) and (b) can be found 2220cm in (a) ^-1Near the stretching vibration absorption peak of C ≡ N be the infrared signature absorption peak of TCNQ, and (b) among the K (TCNQ) C ≡ N infrared absorption peak only than TCNQ red shift in (a) about 20cm ^-1, and be split into 2195cm ^-1And 2181cm ^-1Two peaks, this is the infrared signature absorption peak of K (TCNQ).No strong lattice vibration peak occurs in (b) simultaneously, shows that K (TCNQ) molecule is weak ion-type.In (b), can observe 720cm in addition ^-1Near an absorption peak is arranged, and do not observe this peak in corresponding (a), in Li (TCNQ) infrared spectrum, also find to have this peak.

Relatively (c) and (d) and (e) and (f) find, (c) with (e) infrared absorption spectrum only than (d) with (f) at 2220cm ^-1Many absorption peaks, this is the C ≡ N characteristic absorption peak among the K (TCNQ), and this peak compares with (b), does not almost have any drift.Hence one can see that, and K (TCNQ) only is that physics is dissolved in the macromolecule.

The present invention has made high-quality optical thin film with " ethyl cellulose-methylene chloride-K (TCNQ)-DMF-acetonitrile " system by spin-coating method.Measure its static light storage characteristics, obtained satisfactory result.Fig. 3 is the static test result, shown among the figure 60 times read-write-wipe circulation (can also continue circulation), contrast reaches more than 25, can satisfy the requirement of commercial optical discs.At wavelength is that 365 nanometers have another absorption peak, and herein, contrast is defined as:

$K=2\frac{|R_2-R_1|}{R_2+R_1}\×100\%$

In a word, the present invention has successfully developed K (TCNQ)/polymer body mesentery and has proposed spin coating preparation technology.Experiment shows that this spin-coating film has good wiped rewriting optical storage function.Can be used for the short wavelength and can wipe the rewriting HIGH-DENSITY OPTICAL STORAGE.This membraneous material specifically can be used for ruddiness DVD (wavelength is 650nm) and short wavelength's (wavelength is 405nm) can wipe rewriting optical storage CD.This CD can be made up of substrate (glass or PC), above-mentioned membraneous material and a metallic reflector, and this metallic reflector can be gold, silver or aluminium.In addition, the K (TCNQ) that is dissolved in the macromolecule is unformed, and its particle is significantly smaller than K (TCNQ) particle in the film of vacuum method preparation, so optical noise is less, can obtain high carrier-to-noise ratio.The present invention can wipe the research that rewrites the optical storage function material for high density from now on and the industrialization of optical disc production provides wide prospect.

Description of drawings

Fig. 1 is the visible spectrum characteristic before and after K (TCNQ)/ethyl cellulose film variable color.

Fig. 2 is the infrared absorption spectrum of TCNQ, K (TCNQ), K (TCNQ)/ethyl cellulose and ethyl cellulose.

Fig. 3 is static test result (optical maser wavelength 650nm).

Reading performance number writes performance number and writes pwm value and wipe performance number and wipe pwm value

1.4mw 12mw 600ns 4mw 3500ns

Embodiment

1.K preparation (TCNQ)

2.5g KI is dissolved in 20mlCH ₃Make solution A among the OH, 1.0gTCNQ (Tokyo changes into) is dissolved in 150mlCH ₃Make solution B among the CN, under constantly stirring, solution A is added in the solution B gradually, static 4 hours, obtain mauve K (TCNQ) powder after suction filtration, washing, the drying.

2. the preparation of K (TCNQ) film on the glass substrate

10mg K (TCNQ) is dissolved in 2ml or 6mlCH ₃In the mixed solution of CN and 2ml or 6mlDMF, treat to dissolve fully the back and add 0.3g or 1g ethyl cellulose (import packing), add 4ml or 8mlCH after the dispersed with stirring ₂Cl ₂, sonic oscillation 40min, placement is spent the night.K (TCNQ) Polymer Solution of above-mentioned preparation is spun on the slide infrared lamp oven dry.

3.PC the preparation of K on the substrate (TCNQ) film

6mlCH ₂Cl ₂After mixing with the 1.5ml cellosolve, add the 0.2g ethyl cellulose, fully make solution A after the dissolving, 10mg K (TCNQ) is dissolved in 4mlCH ₃Make solution B in the mixed solution of CN and 2mlDMF, A, B two solution are mixed back sonic oscillation 10-30min, placement is spent the night.Solution with above-mentioned preparation is spun on the PC substrate, the infrared lamp oven dry.

4. test

The visible spectrum that uses UV-240 ultraviolet-visible pectrophotometer (day island proper Tianjin) and NEXUS 470 FT-IR Fourier transform infrared spectrometer (Nicolet) to measure K (TCNQ) film absorbs and the infrared spectrum absorption characteristic.Test static read-write with homemade static test instrument and wiped cycle characteristics.Contrast can be greater than 25.Circulate and do not see obvious deterioration hundreds of times.

Claims (4)

1, a kind of being used for can be wiped the membraneous material that rewrites the short wavelength light storage, coat after it is characterized in that being scattered in the ethyl cellulose by metal organic complex K (TCNQ) on the substrate and prepare, the weight ratio of ethyl cellulose and K (TCNQ) is 2:100-10:100; Here K is a metallic potassium, and TCNQ is 7,7,8,8-four cyano benzoquinones bismethane.

2, a kind of preparation method who is used for to wipe the membraneous material that rewrites the short wavelength light storage, it is characterized in that 10AmgK (TCNQ) is dissolved in (2-6) Aml acetonitrile and (2-6) Aml N, in the mixed solution of dinethylformamide, obtain K (TCNQ)-acetonitrile-N, the dinethylformamide mixed solution; Treat to dissolve fully the back and add the ethyl cellulose of (0.2-1) Amg and (3-8) solution of Aml methylene chloride, sonic oscillation 10-40 minute, thus obtain K (TCNQ) Polymer Solution; Then this K (TCNQ) Polymer Solution is spun on the substrate, the infrared lamp oven dry, A is a scale-up factor here, and K is a metallic potassium, and TCNQ is 7,7,8,8-four cyano benzoquinones bismethane.

3, preparation method according to claim 2 is characterized in that also being added with (1-2) Aml cellosolve in the solution of ethyl cellulose and methylene chloride when substrate adopts polycarbonate substrate, and A is a scale-up factor here.

4, a kind of application of membraneous material according to claim 1 is characterized in that being used for ruddiness DVD or short wavelength and can wipe rewriting optical storage CD.

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