JPH049943A - Spirooxazine recording material - Google Patents

Abstract

PURPOSE:To enhance the light resistance of the recording material and to stabilize both a decoloring state and a color developing state over a long period of time by using prescribed spirooxazines and a bivalent metal ion supplying material in combination. CONSTITUTION:This recording material is constituted by dispersing the spirooxazines (A) and the bivalent metal ion supplying material (B) into a thermoplastic resin film in such a manner that the components A, B form a colored chelate by the effect of heat and are dissociated to the decolored state by visible light. The compd. of formula is usable as the component A. In the formula, R1 denotes lower alkoxyl, lower alkyl, etc.; R2 denotes alkyl or benzyl; R3 denotes lower alkoxyl, hydroxyl group, etc. The complex ion compds. of Ni (II), Cu (II), etc., are usable as the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording material that has excellent recording storage properties and durability against repeated writing and erasing. More specifically, the present invention utilizes spirooxazines, which are photochromic materials, and divalent metals.An optical recording system using conventional technology photochromism is expected to have characteristics such as high speed, high density, and multiplex recording. Therefore, attempts have been made to apply various photochromic compounds as optical information recording materials. However, these technologies have many problems to be solved. Among these, the most important issues are improving the thermodynamic stability of each state of color development and decolorization and the durability of repeated color development and decolorization.

As photochromic compounds, fulgides, spiropyrans, spirooxazines, azobenzenes, thioindigos, and diallylethenes are known. Fulgides [H, G, Hera-1], Diarylethenos [Masahiro Irie et al.,
Journal of Organic Chemistry (J,
Org, Chem,) Volume 53, Page 803, 19
1988] or photooxygenated aromatic polycyclic compounds [R.
Schmidt et al., Journal of the American Chemical Society (J, Am, Chew, Sa.
c,) Volume 102, page 2791, 1980] is
It is a compound that has relatively excellent thermodynamic stability in decoloring and/or coloring states. In addition, spiropyrans have good photoresponsive sensitivity, so much research and development has been conducted on them. Recently, we have been working on the production of compounds with benzothiazoline rings [JP-A-58-37078] and the use of J-aggregate formation in LB films [Eiji Ando, "Nikkei New Materials J
June 30, 1986 issue], or by using bilayer membranes of amphiphilic substances or cyclodextrins, etc., to improve the thermal stability of coloring bodies. [For example, see "New Applications of Photofunctional Polymers J, 1988, published by CMC, supervised by Kunihiro Ichimura." Also, for example, 1°, 3', 3'
-trimethyl-6-nitro-8-methoxyspiro[2H
-1-benzobilane-2,2゛-indoline 1 is copper (
I+) It is known that acetylacetonate and tetrahydrofuran form a chelate in the presence of a trace amount of hydrochloric acid, and based on this, the possibility of stabilizing the color former has been suggested. [Shin Ohno, Journal of the Chemical Society of Japan, page 633, 1
977]. However, spiropyrans have disadvantages in that they have poor repeat durability and are easily photodegraded.

On the other hand, although spirooxazines are far superior to other photochromic compounds in terms of repeated coloring and decoloring durability, the thermodynamic stability of the color formers is low, so they do not last in the dark and do not fade easily. The return to color is extremely fast, completing within a few seconds at room temperature. This characteristic suits the purpose of use as a material for controlling the amount of light in sunglasses, etc., so research into practical application is being actively carried out. However, research and development is at a standstill, as it is actually a negative factor for the purpose of recording materials.

1: Problems to be Solved by the Invention The purpose of the present invention is to provide a recording material using spirooxazines that is highly durable and can remain stable in both decolorized and colored states over a long period of time. It has been done.

The present invention will be explained in detail below.

The spirooxazines used in the present invention include -Means for solving the binding problem As a result of intensive research to dramatically improve the thermal stability of spirooxazines, the oxazinyl The photochromic derivative, which has a coordinating group substituted adjacent to oxygen, forms a stable colored chelate with the tertiary + al metal ion supply substance present in the medium by heating, and the thermal stability of the colored state increases. It was also discovered that this chelate dissociates and returns to a stable decolorized state upon irradiation with visible light, and based on this knowledge, the present invention was accomplished. That is, the present invention provides a recording material comprising a spirooxazine having chelate-forming ability and a divalent metal ion supplying substance dispersed in a medium.

The following compounds can be mentioned. In the formula, R1 is a lower alkoxyl group, a lower alkyl group, an amine group, or an amino group having a substituent, R2 is an alkyl group or a benzyl group, and R3 is a lower alkoxyl group, a hydroxyl group, a piperidinomethyl group, an alkylamino group, or a substituent. amine group, alkyl ketone group, or allyl ketone group. moreover,
Such spirooxazines, which may have a quinoline ring instead of a naphthalene ring in formula (1), can be produced according to known methods.

・The spirooxazine itself has a pale yellow or yellowish green color.・
Obtained as a solid, containing acetone, benzene, tolu 14
, ij ζene, xylene, dichloromethane, dichloroethane,
Soluble in common organic solvents such as chloroform, diethyl ether, tetrahydrofuran, dioxane, ethyl acetate, alcohol and dimethyl sulfoxide. In these soluble solvents or binder resin films, when exposed to ultraviolet light, like other spirooxazines, the colorless ring-closed form is converted to the colored open-ring form, and this ring-open form is stable at room temperature and in the dark. Immediately returns to the colorless closed ring form.

Divalent metal ion supply in the present invention! Examples of the eight substances include nickel (II), copper (II), and cobalt (
II), nitrates such as cadmium (II), chlorides, perchloride oxides, tetraphenylborides, and the like. However, since these metal (II) ion compounds are poorly soluble in the above-mentioned organic solvents, it is more preferable to use metals in which one or two types of ligands are chelated to these metal (II) ion compounds. (II) Using a complex ionic compound. In this case, the ligand may be a diketone compound such as acetylacetone or benzoylacetone, or N,N
Examples include diamine compounds such as '-tetramethylethylenediamine and N,N'-tetraethylethylenediamine. These ligands can be used alone or as a mixture of two, using known methods [for example, Yutaka Fukuda et al., rBull,
Chew, Sac, Jpn, 499.1017, 1976], the gold JX(II) complex ion compound is easily formed by chelate bonding to bimetal(II) ions. The resulting metal(II) complex ion compound is soluble in the above organic solvent.The efficiency of the chelate reaction with the spirooxazines is as follows: It is most effective in the case of metals obtained using diamine compounds alone (
II) It is slightly inferior in the case of complex ionic compounds, and hardly occurs in the case of metal (11) complex ionic compounds obtained using a diketone compound alone. These metal (n) complex ion compounds can be used alone or in a mixture of two or more.

Examples of the binder resin in the present invention include polynylacetic acid, polymethylmethacrylic acid, polychlorinated urethane, polyamide, and copolymers thereof. These resins are dissolved in a suitable solvent, and the photochromic compound and the metal (11) complex ion are mixed to form a resin film of 1tiI. As the solvent, dichloroethane and acetone, which have a small coordination ability to the metal (II) complex ion compound, are preferably used. However, solvents with strong coordinating ability such as alcohol and dimethyl sulfoxide are unsuitable because they interfere with the chelate formation of the spirooxazines. The photochromic compound is preferably used in an amount of 0.002 to 0.01 parts by weight per 1 part by weight of the resin.

The amount of the metal (II) complex ion added is preferably 1 to 10 parts by weight, more preferably 2 to 411 parts by weight, based on one part of the photochromic compound.

When the spirooxazines and the metal (II) complex ion compound are dispersed in a binder resin and dried under reduced pressure, a blue transparent resin film is obtained. This coloration is due to the fact that some of the nuclear spirooxazines form a chelate with the metal (II) complex ion compound. The coloring density depends on the dispersion concentration of the spirooxazines and the metal (1) complex ion compound. This color disappears when irradiated with visible light. When this resin film is further heated or irradiated with ultraviolet light, the quinoidal oxygen and the adjacent substituent R2 of the spirooxazines in the ring-opened form are converted into coexisting third It quickly forms a chelate with the substance, the metal (II) complex ion compound, and is colored deep blue. The absorption spectrum of this colored chelate is -
It's 7R Bashi.

Very slow compared to alone. For example, the time required for the absorbance of the colored chelate to be halved at its absorption maximum in a polyvinyl acetate resin film is approximately three months or more, which is about 10,000 times longer than when only the spirooxazines are dispersed.

The colored chelate returns to its uncolored state by irradiation with visible light.

Even if the decolorized product is stored at room temperature in the dark for a long period of time, there is no color change and no increase in colored chelate is observed. However, irradiation with visible light does not completely restore the color to the colorless state, but the color can be completely restored by immersing it in warm water at about 40°C for about 1 minute or by exposing it to steam. In this case, chelate-forming ability is not lost at all.

The chelate formation of the present invention is performed using spirooxazines other than the spirooxazines, such as 1,3,3-trimethylspiro[indoline-2,3'-[3-formed naphtho[2,1-
This does not occur at all in derivatives that do not have a second coordinating group adjacent to the oxazinyl oxygen, such as bl[1,4]oxazine J.

The spirooxazines are originally photochromic compounds with very good repeat durability both in solution and in the binder resin film, but this excellent property is due to the fact that the metal (+1) complex is The coexistence of ionic compounds does not cause any damage.

Effects of the Invention The recording material of the present invention has the advantage of excellent durability for repeated writing and erasing of records, and can also be used for recording in both thermal and optical modes, so it can be used depending on the purpose. It is.

The recording material of the present invention can be suitably used as a recording material that can be used repeatedly, mainly for the purpose of preserving records for a relatively short period of time or temporarily.

Example Trine-2.3'-[Marnaphth[2,1-bl[1,
4] Oxazine] (hereinafter abbreviated as DMSO) is produced from 5-methoxy-1,3,3-trimethyl-2-methyleneindoline and 3-methoxy-1nitroso-2-naphthol by a dehydration condensation reaction in methanol. Obtained as yellow crystals (melting point, 164-166°C). 3-methoxy-1-
Nitroso-2-naphthol is a white crystal of 3-methoxy-2-naphthol (I!! point, 1
(08-109°C) was nitrosated with sodium nitrite to obtain red crystals.

As a metal (I+) complex ion compound, N1(CIO-h
acetylacetone (hereinafter abbreviated as 1lCac) and N
, N'-tetramethylethylenediamine (hereinafter referred to as tie
A mixed complex ionic compound (abbreviated as d) was prepared and used. The manufacturing method was carried out according to the literature [for example, Yutaka Fukuda et al., Bulletin of Chemical Society of Japan (Bull
, Chew, Soc, Jpn, ) 49 volumes,
1017, 1976], [Ni(aca
c) A red crystalline powder of (tmed)ICIO- was obtained.

This complex ionic compound immediately turned green when exposed to warm air, so it was stored in a dry desiccator.

DMSN obtained above and [Ni(acac)(tmed)ICIO] were added to a 1.2-dichloroethane solution (5 wt%) of polyvinyl acetic acid (hereinafter abbreviated as PVAC).
4 to 0.5wt% and 2.0vt% of PVAC, respectively.
In addition, a resin film was created on a polyester (PET) film by a casting method.

1 set of 1.2-dichloroethane solution removed by evaporation 40
The mixture was dried under reduced pressure at °C for 24 hours to obtain a blue resin film with a thickness of about 100 μm. This resin film was heated in a hair dryer or in an oven at about 60° C. for about 30 seconds to obtain a resin film colored blue.

The maximum absorption wavelength of this resin film is 620 degrees darkness, and its absorbance is approximately 1.0.This coloring is very stable at room temperature and in the dark, and
There was almost no change even after 4 hours (see attached drawing).

In fact, it took more than 3 months for the color density to be halved.

; He-Ne laser light (input = 83
Records were written by irradiating with 3 nm, output 1/:125 mw). The illumination for several seconds is 0.25, which is about 1/4 of the unirradiated area.
The color faded to. The decolorized state was also extremely stable, and no increase in color density was observed even after several months at room temperature in the dark.

For light resistance by continuous irradiation with ultraviolet light, a 500W ultra-high pressure mercury lamp was used to test the Corning colored glass filter (7-5
In step 1), the emission line of 385 nm was mainly extracted, and a 1,2-dichloroethane solution of the photochromic compound and PVA were extracted.
The C resin film was irradiated. In the solution, it took about three and a half hours for the maximum absorbance of the colored material in the visible region to decrease to half of its initial value due to photodeterioration.

On the other hand, the resin film exhibited excellent light resistance, with only a few percent decrease even after 10 hours of irradiation.

Example 2 DMSO and [Ni (ac
ac) (tned)] A PET film coated with PVAC in which CIL was dispersed was irradiated with visible light from a 500 W high-pressure mercury lamp to obtain a transparent film in a decolorized state. The absorbance at 620 nm, which is the absorption needle size of the colored chelate, decreased to about 0.3. The decolored state was extremely stable at room temperature in the dark, and no coloring was observed for more than half a year. This colorless transparent film was printed using a commercially available thermal printer to obtain blue characters. The print results were extremely stable and could be clearly read even after several months of use.

However, this printed result was not completely erased by irradiation with visible light from a 500W high-pressure mercury lamp, but was able to be restored to its original decolorized state by irradiation with a He-Ne laser.

Example 3 A PET film similar to Example 2 was exposed to steam for about 1 minute or soaked in warm water at about 40°C to obtain a colorless and transparent film. 620no+, the maximum absorption of colored chelate
The absorbance was approximately 0, and a completely colorless film was obtained. The decolored state was extremely stable at room temperature in the dark, and no coloring was observed for more than half a year. This colorless transparent film was printed using a commercially available thermal printer to obtain blue characters. Printing conclusion 1. ) The nest was extremely stable and could be clearly read even after several injuries.

(Sword Example 4 In place of DMSO in Example 1, 5″-methoxy-1,3,3-trimethylspiro[indoline-2,3′-[311]naphtho[2
, 1-bl [1,41 oxazine] (hereinafter abbreviated as MSO) was used to produce a PvAC resin film.

The absorption maximum of the colored chelate generated by heating is 502r
m, and its absorbance was about 0.6. It took about 10 days for the absorbance to decrease by half at room temperature.

Recording with He-Ne laser light from a colored state was performed in the same manner as in Example 1, and after several seconds of irradiation, the maximum absorbance in the irradiated area was 0.15, and it disappeared to about 1/4 of the unirradiated area. It was colored. The decolorized state was also extremely stable, with almost no increase in coloring rate being observed semi-permanently at room temperature in the dark.

Further, as in Examples 2 and 3, bright characters could be printed from the decolorized state by printing using a commercially available thermal printer, and the storage stability of the records was good. Furthermore, recording could be erased in the same manner using the methods of Examples 2 and 3.

Comparative Example I A polyvinyl acetic acid resin film in which only DMSO was dispersed was colored by a photochromic reaction caused by ultraviolet light irradiation, but no coloration was observed by heating. The wavelength of maximum absorption of the colored body was 610 nm, and the absorbance of maximum absorption immediately after irradiation with ultraviolet light was about 0.8. At room temperature in the dark, the absorbance at maximum absorption was halved in about 1 minute (see attached drawing). This value is when the metal (II) complex ion compound is added (Example 1)
This is approximately 1/100,000th of that.

When the light resistance by continuous irradiation with ultraviolet light was evaluated in the same manner as in Example 1, about half of the light resistance deteriorated in about 9 hours. Comparing this result with Example 1, it is clear that the metal (II) complex ion compound improves the light resistance.

Note that the value in the absence of the metal (II) complex ion compound is 1,3.3-trimethylspiro[indoline-
2,3'-[3+1]naphtho[2,1-bl[1,4]
As a result of examining the light resistance of Phosphorus 1 at approximately the same level as Oxazine 1 (hereinafter abbreviated as SO), photodeterioration was observed in 5 minutes.

Comparative Example 2 D) In Example 1, SO was used as a photochromic compound instead of ISO, and [Ni(acac)(t
med) ] A fractionated PVAC membrane was prepared with CIDa.

The coloring caused by ultraviolet light irradiation disappeared immediately as in the case where the N1(IJ) compound was not present. Moreover, no coloring occurred upon heating.

[Brief explanation of drawings]

Figure 2 shows changes over time in the absorbance of colored bodies in Example 1 (actual WS) and Comparative Example 1 (broken line).

Claims (1)

[Scope of Claims] 1) A spirooxazine that forms a chelate with a divalent metal ion supply substance under the action of heat and dissociates with visible light, and the divalent metal ion supply substance is dispersed in a thermoplastic resin film. 2) The recording material according to claim 1, wherein the recording material is written in a visible light and the erasure is performed in a thermal mode; 3) The recording material according to claim 1, in which the recording material is written in a thermal mode and the erasure is performed in a visible light mode.