JPH02300287A - Photostabilizer consisting of nitrosoaniline derivative and product containing the same - Google Patents

Abstract

PURPOSE:To obtain a photostabilizer which improves the stability to light of a photodegradable org. substance, especially cyanine coloring matter by using a nitrosoaniline derive. of a specified formula as an active ingredient. CONSTITUTION:A photostabilizer is obtd. by using a nitrosoaniline derive. of formula I (wherein R1 and R2 are each a lower alkyl or a lower hydroxyalkyl; R3 is OH, a lower alkyl, a halogen or H) (e.g. N,N-dimethyl-p-nitrosoaniline of formula II, N,N-dimethyl-3-methyl-4-nitrosoaniline of formula III, etc.) as an active ingredient. Said photostabilizer can improve the stability to light of a photodegradable org. substance, especially a cyanine coloring matter. A photorecording medium with excellent storing characteristics of a recording layer and recording and reproducing characteristics is obtd. by incorporating said photostabilizer in an optical recording medium using a thin film of an org. coloring matter as a recording layer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a photostabilizer, and particularly to a cyanine stabilizer for improving the stability of photodegradable organic substances to light. 0 regarding dye stabilizers and their use
Honmei! ! ! In this book, photodegradable organic substances are a general term for organic substances that undergo changes such as degeneration, deterioration, change, discoloration, and discoloration when exposed to light, and cyanine dyes are particularly important.

[Conventional technology] Organic dyes have traditionally been widely used for coloring fibers and plastics, analytical indicators, photographic photosensitizers, etc.Recently, organic dyes have been used in a different way than before as functional dyes. For example, dye lasers, optical energy conversion, and optical recording are some of the ways in which dyes are used.9 Regardless of which of these applications they are used for, dyes pose several challenges.

Optical recording media using 28 layers of organic dye thin films are also well known. The dyes used in such optical recording media can be used for a long time after the optical recording medium is manufactured, since the medium is exposed to light in various forms during that time.
Since photodegradation occurs and the recording properties of the dye deteriorate, it is an important issue to prevent photodeterioration of the recording medium due to such causes. Addition of various light stabilizers has been carried out as a method for preventing photodeterioration of this type of optical recording medium, but the light stabilizers that have been used conventionally have poor light resistance and compatibility with dyes. Therefore, the storage stability and recording/reproducing characteristics of the recording layer were not fully satisfactory.

On the other hand, forming a thin film on a recording medium is usually carried out by methods such as vapor deposition or coating, and the method of forming a thin film by coating is industrially advantageous compared to other methods in terms of large area, capacitance, etc. In order for the coating method to be adopted, all recording medium materials must be soluble in solvents.However, among the recording medium materials conventionally used, organic dyes are relatively well soluble in general organic solvents. However, many photostabilizers have poor solubility, so 1. There was a drawback that it was strictly necessary to shape the thin film for recording media by the coating method.

The essential properties required for dyes include good dyeability and washing fastness, moderately high density, and high sunlight fastness. Cyanine dyes have attracted attention due to their clear hue and high density (large molecular extinction coefficient), but their use has been limited due to poor sunlight fastness [Horiguchi, synthetic dye, 9.3 tl] (Sankyo Publishing)].

7. Methods for improving sunlight fastness; and 7. In this case, a gold complex having light absorption in the long wavelength range is prepared by adding 24 4'5. Legal (Japanese Patent Publication No. 59-215892, 62-193891, 62-207688, 63-199248, 6
3-19293),! A method of adding a substance that suppresses discoloration due to the element (JP-A-59-55705), a method of introducing a ring into the methine chain (JP-A-62-18708).
No. 8, No. 62-196180, No. 62-207684
No. 83-33477), etc.8 However, none of these proposals solves the problem in one minute, and methods by adding metal chains or improving the structure of the dye do not solve the problem. It also has the disadvantage that it is often difficult to dissolve in various solvents.

[Problems to be Solved by the Invention] Conventional methods of photostabilizing by using additives or improving the dye structure deteriorate the solubility of the dye in solvents, especially amphoteric solvents, so it is necessary to adjust the usage method and amount. In many cases, they were unsatisfied with the resolution of the problem. Therefore, dye I
: A light stabilizer that not only has a Q-friendly light stabilization method, but also has good solubility in solvents and good compatibility with dyes, which can be used as an additive without impairing the solubility of dyes. We have developed and used this as a photostabilizer that helps prevent each of the four photodegradation reactions, for example, as a photostabilizer for organic dyes, especially cyanine dyes, and for use in thin films for optical recording. The problem to be solved by the present invention is to provide a light stabilizer for improving the storage stability and recording/reproducing characteristics of optical recording media used as optical recording media.

[Means to solve the problem] Organic pigments fade or change color when exposed to light, but the mechanism is often unclear.The causes are the structure of the pigment and the environment (e.g. substrate, atmosphere and its pollutants, humidity, temperature). Charles H.
, G11es and Robert B, McKay's review "'The Lightfastness of D
Yes.

A Review''; Textile Re
5earch Journal vol. 33 p. 527
(19631: Kitao, “Chemistry of functional pigments” p. 65
(CMC): Akamatsu, Hanin, et al., “Utilization of Photochemistry” p, I69 (Soy Publishing), etc., but the photobleaching mechanism and photostabilization conditions of cyanine dyes are not clearly specified. Therefore, the present inventor As a result of intensive research, they hypothesized that cyanine dyes undergo photodecomposition (radical decomposition) and discoloration when exposed to light, rather than autooxidation, and developed various radical decomposition inhibitors or compounds predicted to exhibit equivalent functions. We searched for compounds that were effective in photostabilizing cyanine dyes and found a series of highly effective compounds. That is, it is a nitrosoaniline derivative represented by the following general formula (1). They dissolve well in solvents, especially general-purpose chronic solvents such as methanol, ethanol, acetone, etc., and can coexist in the solvent without impairing the favorable properties of cyanine dyes, so they can be used as photostabilizers for cyanine dyes. It's convenient to be cheerful.

- General formula [where %R1 and R8 represent the same or different lower alkyl group (preferably a lower alkyl group having 1 to 3 carbon atoms) or a hydroxy lower alkyl group (preferably a hydroxyethyl group), and R5 is hydroxyl group,
represents any group or atom selected from the group consisting of a lower alkyl group (preferably a lower alkyl group having 1 to 3 carbon atoms), a halogen atom, and a hydrogen atom; It goes without saying that the light stabilizer of the invention is effective when the same compound is used alone, but the names of the inventions that were achieved at the same time as the present invention and filed for a patent on the same day as the present invention are "nitroso group-containing phenol or ``Light stabilizer consisting of a naphthol derivative and its uses'', ``Light stabilizer consisting of a nitrosodiphenylamine derivative and its use'', and ``Light stabilizer consisting of l-vicryl-2゜2-diarylhydrazyl free radical. One of the photostabilizers or 2F! It has been confirmed that the desired effect can be achieved even when used in combination with the above, and that no particular inconvenience occurs due to the combination.

Some specific examples of nitrosoaniline derivatives having the structure represented by the above general formula (1) and which can be particularly advantageously used in carrying out the present invention are as follows.

(1) N,N-dimethyl-p-nitrosoaniline (2)
N,N-diethyl-p-nitrosoaniline (3)N,N
-'dipropyl-p-di-rosoaniline (41N,
N-bis(2-hydroxyethyl)-p-nitrosoaniline (51N, N-dimethyl-3-hydroxy-4-nitrosoaniline (61N), N-dimethyl-3-chloro-4-nitrosoaniline (blank below) (71N, N-dimethyl-3-methyl-4-nitrosoaniline These photostabilizers can be used alone or in combination of two or more types together with organic substances for photostabilization. You can also do it.

Companies using photostabilizers usually use 0.00% per mole of photostabilizing organic substances such as cyanine dyes. The amount may be from 1 mol to 1 mol, but it can be increased or decreased depending on the degree of need. Preferably cyanine dye 1
It is 0.1 to 1 mole per mole. Although it is possible to use more, the color density will naturally become lighter, and depending on the application, the desired color density may not be obtained. Furthermore, if the amount of mold used is small, the effect may not be clear.

Advanced organic substances that can be stabilized by the light stabilizer of the present invention include polymethine dyes, triarylmethane dyes, biryllium dyes, phenanthrene dyes, tetradehydrocholine dyes, and triarylamine dyes. Examples include pigments such as squarylium pigments, croconic methine pigments, and merocyanine pigments. Particularly preferred cyanine dyes that can be used include indolenine cyanine dyes and thiazole cyanine dyes, and a more desirable cyanine dye is indodicarbocyanine. Examples will be described below, but these are shown for illustrative purposes only, and are not intended to limit the present invention. In the examples, the substrate as the object to be colored is a glass plate or polycarbonate. (Although we used a PCj board, of course other substrates such as fibers, etc.
Similar effects can be obtained when paper, film, etc. are used.

Furthermore, an example of using ethanol as a solvent for dissolution is shown. Other positive solvents can also be used, but they are toxic, volatile and
This is because ethanol was the best when considering the erosion of the substrate.8 [Example 1] Add NK242 to 100 parts by weight of ethanol while stirring.
1 (Cyanine dye manufactured by Japan Photosensitive Color Research Institute Co., Ltd.) 3.
0 parts by weight and 1.0 parts of N,N-dimethyl-p-nitrosoaniline (the compound of (1) above) were sequentially added, and stirring was continued for 1 hour at a temperature of 20 to 30°C. Gravity filtration was performed using N012 (for qualitative use), and the filtrate was applied to a glass plate by a spin cord method.

This way it's even! 1! After measuring the maximum absorption wavelength λmax of the clothed glass plate specimen as a measurement standard, a lamp (Irie Seisakusho IDR
irradiated with light of 400 T) for 3 hours, 6 hours, and 9 hours, respectively, starting from the time of measuring λa + ax,
Maximum absorption wavelength λ at that point after irradiation for each of the above specified times
1. Measure max. The fading rate was calculated from the above measurement standards and their measurements (+U). The results are shown in Table 1.

[Example 2] Add NK242 to 100 parts by weight of ethanol while stirring.
3.0 parts by weight of 1 and 0.1 ffiffi parts of N,N-dimethyl-p-nitrosoaniline were added in sequence to 520~
Stirring was continued for 1 hour at a temperature of 30°C. The subsequent operations were performed in exactly the same manner as in Example 1, and the fading rate was calculated. The results are shown in Table 1.

[Comparative Example 1] Add NK242 to 100 parts of ethanol while stirring.
3.0 parts of N,N-dimethyl-p-nitroaniline having a structure represented by the following formula: 0.1 parts of N,N-dimethyl-p-nitroaniline having a structure represented by the following formula were added sequentially, and the mixture was heated to 1 at a temperature of 20 to 30°C
Stirring was continued for an hour. The subsequent operations were performed in exactly the same manner as in Example 1, and the fading rate was calculated. The results are shown in Table 1.

[Example 3] Add NK141 to 100 parts of ethanol while stirring.
4 (Cyanine dye manufactured by Japan Photosensitive Color Research Institute Co., Ltd.) 3
, 01 and N, N-diethyl-p-nitrosoaniline (the compound of (2) above) O, tS were sequentially added to the reactor, and stirring was continued at a temperature of 20 to 30° C. for 1 hour. The subsequent operations were performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 4] Add NK141 to the 100-fold portion of ethanol.
4 to 5.01 parts and N,N-dimethyl-3-hydroxy-4-nitrosoaniline (compound (5) above) 0
．． Three portions were added one after another, and stirring was continued for 1 hour at a temperature of 20 to 30°C. The subsequent operations were performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 5] Add NK141 to 100 parts of ethanol while stirring.
5.0 parts by weight of 4, N,N-dihydroxyethyl-p-
Nitrosoaniline (compound of (4) above) 0.5 weight 1i
The mixture was successively added to the mixture, and stirring was continued for 1 hour at a temperature of 20 to 30°C. The subsequent operations were performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2] NK141 was added to 100 parts by weight of ethanol while stirring.
5,0 parts of 4 and 0.5 parts of N,N-dimethyl-p-chloroaniline having a structure represented by the following formula were added one after another and stirred at a temperature of 20 to 30°C for 1 hour. continued. The subsequent operations were performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 6] NK242 was stirred into 100 parts by weight of ethanol.
1 to 3. A portion of OM and 1.0 parts of N,N-dimethyl-p-nitrosoaniline (above (+1 compound)) were sequentially added, and stirring was continued for 1 hour at a temperature of 20 to 30°C.Following operations The same procedure as in Example 1 was carried out except that a 2PC board was used as a substrate and the droplets were applied thereto.The results are shown in Table 1.

[Comparative Example 3] Add N to ethanol + 00ffiffi part while stirring.
3.0 parts by weight of K2421 was added, and stirring was continued for 1 hour at a temperature of 20 to 30°C. Other operations were carried out in the same manner as in Example 1, except that no aniline derivative was used. The results are shown in Table 1.

[Comparative Example 4] Add NK1 to 100 parts of ethanol while stirring.
Add 3.0 parts by weight of 414 and heat at a temperature of 20 to 30°C.
Stirring was performed for hours. The aniline derivative was not used, and other operations were performed in the same manner as in Example 1. The results are shown in Table 1.

Table 1 below summarizes the experimental results of each Example and each Comparative Example and shows the relationship between light irradiation time and color fading rate.

(The following is a blank space) Table 1 [Effects of the Invention] As can be seen from the experimental results shown in Table 1, the effects of using nitrosoaniline derivatives as light stabilizers are remarkable.

Since this compound has good solubility, a quantitative effect can be expected (Examples 1 and 2).Also, a comparison of Example 1 (using a glass plate) and Example 6 (using a PC plate) reveals the difference in substrates. There is almost no difference in effectiveness depending on the type of treatment, and the use of nitrosoaniline derivatives is effective in all cases.

By adding and using these derivatives as a light stabilizer in an optical recording medium using a thin film of an organic dye as a recording layer, an optical recording medium with excellent recording layer storage stability and recording/reproducing characteristics can be obtained.

Claims (6)

[Claims] (1) General formula▲ Numerical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (However, R_1 and R_2 represent the same or different lower alkyl group or hydroxy lower alkyl group, and R_3 is a hydroxyl group. , a lower alkyl group, a halogen atom, and a hydrogen atom). (2) General formula▲ Numerical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (However, R_1 and R_2 represent the same or different lower alkyl group or hydroxy lower alkyl group, and R_3 is a hydroxyl group. , a lower alkyl group, a halogen atom, and a hydrogen atom). Stabilizer. (3) The light stabilizer according to claim 2, wherein the organic substance is a pigment. (4) The light stabilizer according to claim 3, wherein the dye is a cyanine dye. (5) General formula▲ Numerical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (However, R_1 and R_2 represent the same or different lower alkyl group or hydroxy lower alkyl group, and R_3 is a hydroxyl group. , a lower alkyl group, a halogen atom, and a hydrogen atom.] An optical recording medium comprising a photostabilized nitrosoaniline derivative. (6) The optical recording medium according to claim 5, wherein the optical recording medium is a recording medium containing a cyanine dye.